Rat dug 400 milijuna godina u tvom ormariću s dodacima prehrani

Zamišljamo da je scena tekla otprilike ovako:

• Saulkworm Goodman: Uzmi taj iminošećer i gubi se. Ti i ja, mi smo završili.

• Walter White Mulberry: :::prijeteći::: Završit ćemo kada ja kažem da smo završili!

Abstract

The plant kingdom produces hundreds of thousands of low molecular weight organic compounds. Based on the assumed functions of these compounds, the research community has classified them into three overarching groups: primary metabolites, which are directly required for plant growth; secondary (or specialized) metabolites, which mediate plant–environment interactions; and hormones, which regulate organismal processes and metabolism. For decades, this functional trichotomy of plant metabolism has shaped theory and experimentation in plant biology. However, exact biochemical boundaries between these different metabolite classes were never fully established. A new wave of genetic and chemical studies now further blurs these boundaries by demonstrating that secondary metabolites are multifunctional; they can function as potent regulators of plant growth and defense as well as primary metabolites sensu lato. Several adaptive scenarios may have favored this functional diversity for secondary metabolites, including signaling robustness and cost-effective storage and recycling. Secondary metabolite multifunctionality can provide new explanations for ontogenetic patterns of defense production and can refine our understanding of plant–herbivore interactions, in particular by accounting for the discovery that adapted herbivores misuse plant secondary metabolites for multiple purposes, some of which mirror their functions in plants. In conclusion, recent work unveils the limits of our current functional classification system for plant metabolites. Viewing secondary metabolites as integrated components of metabolic networks that are dynamically shaped by environmental selection pressures and transcend multiple trophic levels can improve our understanding of plant metabolism and plant–environment interactions.

Abstract

Alkaloids represent a highly diverse group of compounds that are related only by the occurrence of a nitrogen atom in a heterocyclic ring. Plants are estimated to produce approximately 12,000 different alkaloids, which can be organized into groups according to their carbon skeletal structures. Alkaloid biosynthesis in plants involves many catalytic steps, catalyzed by enzymes that belong to a wide range of protein families. The characterization of novel alkaloid biosynthetic enzymes in terms of structural biochemistry, molecular and cell biology, and biotechnological applications has been the focus of research over the past several years. The application of genomics to the alkaloid field has accelerated the discovery of cDNAs encoding previously elusive biosynthetic enzymes. Other technologies, such as large-scale gene expression analyses and metabolic engineering approaches with transgenic plants, have provided new insights into the regulatory architecture of alkaloid metabolism.

Iako riječ budi slike rukavica u liječničkoj ordinaciji, lateks je stručni izraz za svaku koloidnu disperziju polimernih čestica u tekućini. Sintetskih lateksa ima mnogo, a prirodni, biljni lateksi javljaju se kao mliječne tekućine, emulzije bjelančevina, alkaloida, šećera, škroba, ulja, tanina i guma, koje se u dodiru sa zrakom stvrdnjavaju.

Značenja izraza lateks i kaučuk djelomično se preklapaju, jer prirodni kaučuk iz kaučukovca doista jest lateks. Među druge poznate primjere spadaju mliječna tekućina makovih biljaka, od koje se izrađuju opijatni proizvodi, i chicle, od kojeg su se prvotno izrađivale žvakaće gume.

Abstract

Wounding of the leaves of potato or tomato plants by adult Colorado potato beetles, or their larvae, induces a rapid accumulation of a proteinase inhibitor throughout the plants' tissues that are exposed to air. This effect of insect damage can be simulated by mechanically wounding the leaves. The transport of a factor out of damaged leaves takes place rapidly after the wound is inflicted and the levels of proteinase inhibitor, in both damaged and adjacent leaves, rises strikingly within a few hours. The rapid accumulation of a powerful inhibitor of major intestinal proteinases of animals in response to wounding of the leaves is probably a defense mechanism.

Abstract

Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees’ bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.

Abstract

Preharvest applications of methyl jasmonate (MeJA) have been shown to improve postharvest fruit quality in strawberry fruit. However, the effectiveness of consecutive field applications at different phenological stages on the reinforcement of the antioxidant capacity remains to be analyzed. To determine the best antioxidant response of strawberry (Fragaria × ananassa ‘Camarosa’) fruit to different numbers and timing of MeJA applications, we performed three differential preharvest treatments (M1, M2, and M3) consisted of successive field applications of 250 μmol L-1 MeJA at flowering (M3), large green (M2 and M3), and ripe fruit stages (M1, M2, and M3). Then, we analyzed their effects on fruit quality parameters [firmness, skin color, soluble solids content/titratable acidity (SSC/TA) ratio, fruit weight at harvest, and weight loss] along with anthocyanin and proanthocyanidin (PA) accumulation; the antioxidant-related enzymatic activity of catalase (CAT), guaiacol peroxidase (POX), and ascorbate peroxidase (APX); the total flavonoid and polyphenol content, antioxidant capacity, and ascorbic acid content during postharvest storage (0, 24, 48, and 72 h). We also evaluated the effect on lignin, total carbon and nitrogen (%C and N), lipid peroxidation, and C and N isotopes signatures on fruits. Remarkably, the results indicated that MeJA treatment increases anthocyanin and PA contents as well as CAT activity in postharvest storage, depending on the number of preharvest MeJA applications. Also, M3 fruit showed a higher ascorbic acid content compared to control at 48 and 72 h. Noticeably, the anthocyanin content and CAT activity were more elevated in M3 treatment comparing with control at all postharvest times. In turn, APX activity was found higher on all MeJA-treated fruit independent of the number of applications. Unlike, MeJA applications did not generate variations on fruit firmness and weight, lignin contents, % C and N, and in lipid peroxidation and water/nitrogen use efficiency according to C and N isotope discrimination. Finally, we concluded that an increasing number of MeJA applications (M3 treatment) improve anthocyanin, PA, ascorbic acid contents, and CAT activity that could play an essential role against reactive oxygen species, which cause stress that affects fruits during postharvest storage.

Plants produce metabolites that directly decrease herbivore performance, and as a consequence, herbivores are selected for resistance to these metabolites. To determine whether these metabolites actually function as defenses requires measuring the performance of plants that are altered only in the production of a certain metabolite. To date, the defensive value of most plant resistance traits has not been demonstrated in nature. We transformed native tobacco (Nicotiana attenuata) with a consensus fragment of its two putrescine N-methyl transferase (pmt) genes in either antisense or inverted-repeat (IRpmt) orientations. Only the latter reduced (by greater than 95%) constitutive and inducible nicotine. With D4-nicotinic acid (NA), we demonstrate that silencing pmt inhibits nicotine production, while the excess NA dimerizes to form anatabine. Larvae of the nicotine-adapted herbivore Manduca sexta (tobacco hornworm) grew faster and, like the beetle Diabrotica undecimpunctata, preferred IRpmt plants in choice tests. When planted in their native habitat, IRpmt plants were attacked more frequently and, compared to wild-type plants, lost 3-fold more leaf area from a variety of native herbivores, of which the beet armyworm, Spodoptera exigua, and Trimerotropis spp. grasshoppers caused the most damage. These results provide strong evidence that nicotine functions as an efficient defense in nature and highlights the value of transgenic techniques for ecological research.

Zapravo bi The Raison d’Être of Secondary Plant Substances mogla biti i cijela brend filozofija Junaia...

Isti onaj Paul Ehrlich koji je napisao The Population Bomb, glasoviti spis o apokaliptičnoj vjerojatnosti društvenog i demografskog sloma zbog posljedica prenapučenosti.

Znanost o leptirima je, blago rečeno, prošla test vremena s nešto više uspjeha.

Abstract

Plants are attacked by a broad array of herbivores and pathogens. In response, plants deploy an arsenal of defensive traits. In Brassicaceae, the glucosinolate–myrosinase complex is a sophisticated two-component system to ward off opponents. However, this so-called ‘‘mustard oil bomb’’ is disarmed by a glucosinolate sulfatase of a crucifer specialist insect, diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae). Sulfatase activity of this enzyme largely prevents the formation of toxic hydrolysis products arising from this plant defense system. Importantly, the enzyme acts on all major classes of glucosinolates, thus enabling diamondback moths to use a broad range of cruciferous host plants.

Abstract

A new spectrophotometric assay has been used to determine the gross concentration of cardiac glycoside in individual monarch butterflies. Adults sampled during the fall migration in four areas of eastern North America exhibited a wide variation in cardiac glycoside concentration. The correlation between spectrophotometrically measured concentrations and emetic dose determinations supports the existence of a broad palatability spectrum in wild monarch butterflies. The cardiac gylcoside concentration is greater in females than in males and is independent of the dry weight of the butterflies; contrary to prediction, both the concentration mean and variance decrease southward. The defensive advantage of incorporating cardiac glycosides may be balanced by detrimental effects on individual viability.

Abstract

Identifying the genetic mechanisms of adaptation requires the elucidation of links between the evolution of DNA sequence, phenotype, and fitness. Convergent evolution can be used as a guide to identify candidate mutations that underlie adaptive traits, and new genome editing technology is facilitating functional validation of these mutations in whole organisms. We combined these approaches to study a classic case of convergence in insects from six orders, including the monarch butterfly (Danaus plexippus), that have independently evolved to colonize plants that produce cardiac glycoside toxins. Many of these insects evolved parallel amino acid substitutions in the α-subunit (ATPα) of the sodium pump (Na+/K+-ATPase), the physiological target of cardiac glycosides. Here we describe mutational paths involving three repeatedly changing amino acid sites (111, 119 and 122) in ATPα that are associated with cardiac glycoside specialization. We then performed CRISPR–Cas9 base editing on the native Atpα gene in Drosophila melanogaster flies and retraced the mutational path taken across the monarch lineage. We show in vivo, in vitro and in silico that the path conferred resistance and target-site insensitivity to cardiac glycosides, culminating in triple mutant ‘monarch flies’ that were as insensitive to cardiac glycosides as monarch butterflies. ‘Monarch flies’ retained small amounts of cardiac glycosides through metamorphosis, a trait that has been optimized in monarch butterflies to deter predators. The order in which the substitutions evolved was explained by amelioration of antagonistic pleiotropy through epistasis. Our study illuminates how the monarch butterfly evolved resistance to a class of plant toxins, eventually becoming unpalatable, and changing the nature of species interactions within ecological communities.

About this paper

Evolution printed no abstracts in 1964, so this founding paper has none; what follows is our summary, not the publisher’s text. Ehrlich and Raven surveyed the food plants of butterfly families worldwide and noticed that related butterflies feed on related plants, with plant chemistry as the organizing thread. They proposed a stepwise engine: a plant lineage that evolves a novel chemical defense escapes its herbivores and diversifies into the breathing room, until some insect lineage cracks the defense and radiates in turn onto the newly available hosts. This reciprocal process, later named escape-and-radiate coevolution, made plant secondary compounds a central driver of the diversity of both plants and the insects that eat them.

Abstract

The advent of embryophytes (land plants) is among the most important evolutionary breakthroughs in Earth history. It irreversibly changed climates and biogeochemical processes on a global scale; it allowed all eukaryotic terrestrial life to evolve and to invade nearly all continental environments. Before this work, the earliest unequivocal embryophyte traces were late Darriwilian (late Middle Ordovician; c. 463-461 million yr ago (Ma)) cryptospores from Saudi Arabia and from the Czech Republic (western Gondwana). Here, we processed Dapingian (early Middle Ordovician, c. 473-471 Ma) palynological samples from Argentina (eastern Gondwana). We discovered a diverse cryptospore assemblage, including naked and envelope-enclosed monads and tetrads, representing five genera. Our discovery reinforces the earlier suggestion that embryophytes first evolved in Gondwana. It indicates that the terrestrialization of plants might have begun in the eastern part of Gondwana. The diversity of the Dapingian assemblage implies an earlier, Early Ordovician or even Cambrian, origin of embryophytes. Dapingian to Aeronian (Early Silurian) cryptospore assemblages are similar, suggesting that the rate of embryophyte evolution was extremely slow during the first c. 35-45 million yr of their diversification. The Argentinean cryptospores predate other cryptospore occurrences by c. 8-12 million yr, and are currently the earliest evidence of plants on land.

Abstract

A few remarkable finds document the colonization of land by animals and plants in the mid-Palaeozoic, but much rarer is unequivocal evidence for plant-animal interaction. Here we announce the discovery of coprolites (fossil faeces) in Upper Silurian (412 Myr) and Lower Devonian (390 Myr) rocks from the Welsh Borderland that pre-date examples of similar composition in the Carboniferous by about 90 million years. The majority consist predominantly of undigested land-plant spores with varying proportions of cuticles, tubes and less readily identifiable (presumably plant) material. Because coeval animal fossils of suitable size are carnivores, direct evidence for the coprolite producers is lacking, but we speculate that they could have been spore eaters (and hence the earliest example of herbivory of higher plants) or detritivores similar to modern millipedes. In either case, they demonstrate the cycling of primary productivity in early terrestrial ecosystems.

Abstract

This study presents a new high-precision 40Ar/39Ar age for the Devonian hot-spring system at Rhynie. Hydrothermal K-feldspar sampled from two veins that represent feeder conduits and a hydrothermally altered andesite wall rock, date the hydrothermal activity, the fossilised biota, and syn K-feldspar gold mineralization at 403.9 ± 2.1 Ma (2σ). Oxygen isotope data for the parent fluid (−4‰ to 2‰) show that the K-feldspar was precipitated from a dominantly meteoric fluid, which mixed with magmatic fluids from a degassing magma chamber. The 40Ar/39Ar age (403.9 ± 2.1 Ma [2σ]) when recalculated (407.1 ± 2.2 Ma [2σ]) with respect to the astronomically tuned age for Fish Canyon sanidine (28.201 ± 0.023 Ma [1σ]), also provides a robust marker for the polygonalis-emsiensis Spore Assemblage Biozone within the Pragian-?earliest Emsian. Furthermore, the age identifies the Devonian pull-apart volcano-sedimentary basins of the British and Irish Caledonides (and their root zones), as specific targets for future gold exploration.

Abstract

Fossils in the Pragian Rhynie cherts, Aberdeenshire, Scotland, are preserved with exquisite cellular detail, and provide much information on Early Devonian terrestrial and freshwater ecosystems. The fossils include abundant and diverse coprolites which demonstrate the existence of consumers differing in life-habit and diet. The coprolites are small (0.5-3 mm) and diverse in morphology and content, including groups of amorphous coprolites as well as coprolites with identifiable, particulate content. The present authors define three new ichnogenera to accommodate these coprolites: Lancifaex encompasses elongate coprolites with particulate content, and includes three ichnospecies, distinguished on morphology, L. simplex, L. divisa and L. moniliforma. Rotundafaex encompasses rotund coprolites with particulate content, and includes a single ichnospecies, R. aggregata. Bacillafaex encompasses rod-shaped coprolites with amorphous content, and includes two ichnospecies, distinguished on size, B. constipatus and B. mina. Typically, plant spores do not dominate the content of these coprolites, but the population does include some spore-rich coprolites. The presence of spore-rich coprolites in this diverse assemblage adds evidence to the debate on spore-feeding as a nutritional strategy in early terrestrial ecosystems. The authors conclude that the coprolites described here indicate at least four types of consumer including detritivores and herbivores. Spore-rich coprolites might suggest sporivory; however, comparison with the faeces of modern millipedes demonstrates that they might equally well be the product of detritivores. The continuum observed here between spore-rich and spore-poor coprolites implies that, in this assemblage, spore-rich coprolites do not constitute a distinct group. Rather, they are part of a group of elongate, ellipsoidal coprolites with heterogeneous content that includes, at one extreme, coprolites which lack plant spores, and at the other, coprolites which contain abundant plant spores.

Abstract

The molecular origin of standard metabolic rate and thermogenesis in mammals is examined. It is pointed out that there are important differences and distinctions between the cellular reactions that 1) couple to oxygen consumption, 2) uncouple metabolism, 3) hydrolyze ATP, 4) control metabolic rate, 5) regulate metabolic rate, 6) produce heat, and 7) dissipate free energy. The quantitative contribution of different cellular reactions to these processes is assessed in mammals. We estimate that approximately 90% of mammalian oxygen consumption in the standard state is mitochondrial, of which approximately 20% is uncoupled by the mitochondrial proton leak and 80% is coupled to ATP synthesis. The consequences of the significant contribution of proton leak to standard metabolic rate for tissue P-to-O ratio, heat production, and free energy dissipation by oxidative phosphorylation and the estimated contribution of ATP-consuming processes to tissue oxygen consumption rate are discussed. Of the 80% of oxygen consumption coupled to ATP synthesis, approximately 25-30% is used by protein synthesis, 19-28% by the Na(+)-K(+)-ATPase, 4-8% by the Ca2(+)-ATPase, 2-8% by the actinomyosin ATPase, 7-10% by gluconeogenesis, and 3% by ureagenesis, with mRNA synthesis and substrate cycling also making significant contributions. The main cellular reactions that uncouple standard energy metabolism are the Na+, K+, H+, and Ca2+ channels and leaks of cell membranes and protein breakdown. Cellular metabolic rate is controlled by a number of processes including metabolic demand and substrate supply. The differences in standard metabolic rate between animals of different body mass and phylogeny appear to be due to proportionate changes in the whole of energy metabolism. Heat is produced by some reactions and taken up by others but is mainly produced by the reactions of mitochondrial respiration, oxidative phosphorylation, and proton leak on the inner mitochondrial membrane. Free energy is dissipated by all cellular reactions, but the major contributions are by the ATP-utilizing reactions and the uncoupling reactions. The functions and evolutionary significance of standard metabolic rate are discussed.

Abstract

Berberine is an effective antimicrobial and antidiabetic alkaloid, primarily extracted from divergent botanical lineages, specifically Coptis (Ranunculales, early-diverging eudicot) and Phellodendron (Sapindales, core eudicot). In comparison with its known pathway in Coptis species, its biosynthesis in Phellodendron species remains elusive. Using chromosome-level genome assembly, coexpression matrix, and biochemical assays, we identified six key steps in berberine biosynthesis from Phellodendron amurense, including methylation, hydroxylation, and berberine bridge formation. Notably, we discovered a specific class of O-methyltransferases (NOMT) responsible for N-methylation. Structural analysis and mutagenesis of PaNOMT9 revealed its unique substrate-binding conformation. In addition, unlike the classical FAD-dependent berberine bridge formation in Ranunculales, Phellodendron uses a NAD(P)H-dependent monooxygenase (PaCYP71BG29) for berberine bridge formation, originating from the neofunctionalization of tryptamine 5-hydroxylase. Together, these findings reveal the convergence of berberine biosynthesis between Coptis and Phellodendron and signify the role of the convergent evolution in plant specialized metabolisms.

Abstract

Multidrug resistance pumps (MDRs) protect microbial cells from both synthetic and natural antimicrobials. Amphipathic cations are preferred substrates of MDRs. Berberine alkaloids, which are cationic antimicrobials produced by a variety of plants, are readily extruded by MDRs. Several Berberis medicinal plants producing berberine were found also to synthesize an inhibitor of the NorA MDR pump of a human pathogen Staphylococcus aureus. The inhibitor was identified as 5'-methoxyhydnocarpin (5'-MHC), previously reported as a minor component of chaulmoogra oil, a traditional therapy for leprosy. 5'-MHC is an amphipathic weak acid and is distinctly different from the cationic substrates of NorA. 5'-MHC had no antimicrobial activity alone but strongly potentiated the action of berberine and other NorA substrates against S. aureus. MDR-dependent efflux of ethidium bromide and berberine from S. aureus cells was completely inhibited by 5'-MHC. The level of accumulation of berberine in the cells was increased strongly in the presence of 5'-MHC, indicating that this plant compound effectively disabled the bacterial resistance mechanism against the berberine antimicrobial.

Abstract

Evolving antibiotic resistance of bacteria is a prevailing global challenge in health care and requires the development of safe and efficient alternatives to classic antibiotics. Photodynamic Inactivation (PDI) has proven to be a promising alternative for treatment of a broad range of microorganisms. Photodynamic Inactivation uses photoactive molecules that generate reactive oxygen species (ROS) upon illumination and in the presence of oxygen, which immediately kill pathogenic target organisms. Relevant photoactive properties are provided by berberine. Originally extracted from Barberry (Berberis vulgaris), it is a natural compound widely used in Traditional Chinese Medicine for its antimicrobial and anti-inflammatory effects. With this study, we demonstrated the potential of berberine chloride hydrate (Ber) as a photosensitizer for PDI of important human pathogens, Gram(+) Staphylococcus capitis subsp. capitis, Gram(+) Staphylococcus aureus, and Gram(−) Escherichia coli. In vitro experiments on planktonic and biofilm cultures were conducted focusing on Ber activated with visible light in the blue wavelength range. The number of planktonic S. capitis cells was reduced by 7 log10 steps using 100 µM Ber (5 min incubation, illumination with 435 nm LED array, radiant exposure 25 J/cm2). For an antibacterial effect of 4 log10 steps, static S. capitis biofilms required 1 mM Ber, a drug-to-light interval of 60 min, and illumination with 100 J/cm2. Almost all planktonic cells of Staphylococcus aureus could be photokilled using 100 µM Ber (drug-to-light interval of 30 min, radiant exposure 25 J/cm2). Biofilms of S. aureus could be phototreated (3 log10 steps inactivation) when using 1 mM Ber incubated for 5 min and photoactivated with 100 J/cm2. The study is highlighted by the proof that PDI treatment using Ber showed an antibacterial effect on Gram(−) E. coli. Planktonic cells could be reduced by 3 log10 steps with 100 µM Ber (5 min incubation, 435 nm, 25 J/cm2). With 5 mM ethylenediamine tetraacetic acid disodium salt dihydrate (Na2EDTA) or 1.2% polyaspartic acid (PASA) in addition, a relative inactivation of 4 log10 steps and 7 log10 steps, respectively, was detectable. Furthermore, we showed that an antibacterial effect of 3.4 log10 towards E. coli biofilms was given when using 1 mM Ber (5 min incubation, 435 nm, 100 J/cm2). These results underscore the significance of PDI-treatment with Ber as a natural compound in combination with blue light as valuable antimicrobial application.

Abstract

Carnosic acid, a phenolic diterpene specific to the Lamiaceae family, is highly abundant in rosemary (Rosmarinus officinalis). Despite numerous industrial and medicinal/pharmaceutical applications of its antioxidative features, this compound in planta and its antioxidant mechanism have received little attention, except a few studies of rosemary plants under natural conditions. In vitro analyses, using high-performance liquid chromatography-ultraviolet and luminescence imaging, revealed that carnosic acid and its major oxidized derivative, carnosol, protect lipids from oxidation. Both compounds preserved linolenic acid and monogalactosyldiacylglycerol from singlet oxygen and from hydroxyl radical. When applied exogenously, they were both able to protect thylakoid membranes prepared from Arabidopsis (Arabidopsis thaliana) leaves against lipid peroxidation. Different levels of carnosic acid and carnosol in two contrasting rosemary varieties correlated with tolerance to lipid peroxidation. Upon reactive oxygen species (ROS) oxidation of lipids, carnosic acid was consumed and oxidized into various derivatives, including into carnosol, while carnosol resisted, suggesting that carnosic acid is a chemical quencher of ROS. The antioxidative function of carnosol relies on another mechanism, occurring directly in the lipid oxidation process. Under oxidative conditions that did not involve ROS generation, carnosol inhibited lipid peroxidation, contrary to carnosic acid. Using spin probes and electron paramagnetic resonance detection, we confirmed that carnosic acid, rather than carnosol, is a ROS quencher. Various oxidized derivatives of carnosic acid were detected in rosemary leaves in low light, indicating chronic oxidation of this compound, and accumulated in plants exposed to stress conditions, in parallel with a loss of carnosic acid, confirming that chemical quenching of ROS by carnosic acid takes place in planta.

Abstract

Rosemary plants were analysed using HPLC and eight different compounds (vanillic acid, caffeic acid, rosmarinic acid, naringin, hispidulin, cirsimaritin, carnosol and carnosic acid) were identified and quantified. The analysis of the DPPH radical scavenging activity revealed that rosmarinic and carnosic acids were the best rosemary scavengers with IC50 values of 27 and 32 µM, respectively. Environmental influences on rosmarinic and carnosic acids content in rosemary plants were studied over a period of one year under southern UK conditions. Carnosic acid reached the maximum concentrations in December, decreasing by 50% during the summer months, while rosmarinic acid showed a constant concentration during the year.

Abstract

The lipid-soluble antioxidants α-tocopherol and carnosic acid were studied in field-grown rosemary (Rosmarinus officinalis L.) plants subjected to drought. During summer in the Mediterranean region, the predawn water potential decreased to −3 MPa and the relative water content to 42%, which caused a depletion of the maximum diurnal CO2 assimilation rate by 80%. Meanwhile, the maximum efficiency of photosystem II photochemistry and the chlorophyll content of leaves remained unaltered, indicative of the absence of photooxidative damage. The concentration of α-tocopherol increased by 15-fold and that of carotenoids by approximately 26% in response to water stress. Enhanced formation of the highly oxidized abietane diterpenes isorosmanol (by 25%) and dimethyl isorosmanol (by 40%) was observed during the summer as result of the oxidation of carnosic acid, which decreased by 22%. The large amounts of carnosic acid, α-tocopherol, and carotenoids present in rosemary leaves might contribute to the prevention of oxidative damage in plants exposed to drought.

Abstract

Ultraviolet (UV) radiation is a small fraction of the solar spectrum, which acts as a key environmental modulator of plant function affecting metabolic regulation and growth. Plant species endemic to the Andes are well adapted to the harsh features of high-altitude climate, including high UV radiation. Maca (Lepidium meyenii Walpers) is a member of Brassicaceae family native to the central Andes of Peru, which grows between 3500 and 4500 m of altitude, where only highland grasses and few hardy bushes can survive. Even though maca has been the focus of recent researches, mainly due to its nutraceutical properties, knowledge regarding its adaptation mechanisms to these particular natural environmental conditions is scarce. In this study, we manipulated solar UV radiation by using UV-transmitting (Control) or blocking (UV-block) filters under field conditions (4138 m above the sea level) in order to understand the impact of UV on morphological and physiological parameters of maca crops over a complete growing season. Compared to the UV-blocking filter, under control condition a significant increase of hypocotyl weight was observed during the vegetative phase together with a marked leaf turnover. Although parameters conferring photosynthetic performance were not altered by UV, carbohydrate allocation between above and underground organs was affected. Control condition did not influence the content of secondary metabolites such as glucosinolates and phenolic compounds in hypocotyls, while some differences were observed in the rosettes. These differences were mainly related to leaf turnover and the protection of new young leaves in control plants. Altogether, the data suggest that maca plants respond to strong UV radiation at high altitudes by a coordinated remobilization and relocation of metabolites between source and sink organs via a possible UV signaling pathway.

About this guide

A joint recommendation of the World Health Organization, the World Meteorological Organization, the United Nations Environment Programme and the International Commission on Non-Ionizing Radiation Protection (WHO/SDE/OEH/02.2, 2002). In the WHO’s own words, the Global Solar UV Index “is a simple measure of the UV radiation level at the Earth’s surface and an indicator of the potential for skin damage”. The guide defines the exposure categories as published: Low (under 2), Moderate (3 to 5), High (6 to 7), Very High (8 to 10) and Extreme (11 and above). Extreme is the top category and it is open-ended: above 11, the scale simply stops subdividing.

Abstract

Since ancient times, mulberry leaves (Morus spp.) have been used to rear the silkworm Bombyx mori. Because the silkworm grows well on mulberry leaves, the toxicities and defensive activities of these leaves against herbivorous insects have been overlooked. Here we show that mulberry leaves are highly toxic to caterpillars other than the silkworm B. mori, because of the ingredients of the latex, a milky sap exuded from mulberry leaf veins. The toxicity of mulberry leaves was lost when the latex was eliminated from the leaves, and artificial diets containing latex showed toxicity. Mulberry latex contained very high concentrations of alkaloidal sugar-mimic glycosidase inhibitors reported to have antidiabetic activities, such as 1,4-dideoxy-1,4-imino-d-arabinitol, 1-deoxynojirimycin, and 1,4-dideoxy-1,4-imino-d-ribitol. The overall concentrations of these inhibitors in latex reached 1.5-2.5% (8-18% dry weight) in several mulberry varieties, which were ≈100 times the concentrations previously reported from whole mulberry leaves. These sugar-mimic alkaloids were toxic to caterpillars but not to the silkworm B. mori, indicating that the silkworm can circumvent the mulberry tree's defense. Our results suggest that latex ingredients play key roles in defense of this tree and of other plants against insect herbivory, and they imply that plant latexes are treasuries of bioactive substances useful as medicines and pesticides.

Abstract

We searched in this study for novel agonists of transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and transient receptor potential cation channel, subfamily A, member 1 (TRPA1) in pepper, focusing attention on 19 compounds contained in black pepper. Almost all the compounds in HEK cells heterogeneously expressed TRPV1 or TRPA1, increased the intracellular Ca2+ concentration ([Ca2+]i) in a concentration-dependent manner. Among these, piperine, isopiperine, isochavicine, piperanine, pipernonaline, dehydropipernonaline, retrofractamide C, piperolein A, and piperolein B relatively strongly activated TRPV1. The EC50 values of these compounds for TRPV1 were 0.6-128 μM. Piperine, isopiperine, isochavicine, piperanine, piperolein A, piperolein B, and N-isobutyl-(2E,4E)-tetradeca-2,4-diamide also relatively strongly activated TRPA1, the EC50 values of these compounds for TRPA1 were 7.8-148 μM. The Ca2+ responses of these compounds for TRPV1 and TRPA1 were significantly suppressed by co-applying each antagonist. We identified in this study new transient receptor potential (TRP) agonists present in black pepper and found that piperine, isopiperine, isochavicine, piperanine, piperolein A, and piperolein B activated both TRPV1 and TRPA1.

Abstract

We have characterised the effects of piperine, a pungent alkaloid found in black pepper, on the human vanilloid receptor TRPV1 using whole-cell patch-clamp electrophysiology. Piperine produced a clear agonist activity at the human TRPV1 receptor yielding rapidly activating whole-cell currents that were antagonised by the competitive TRPV1 antagonist capsazepine and the non-competitive TRPV1 blocker ruthenium red. The current-voltage relationship of piperine-activated currents showed pronounced outward rectification (25±4-fold between −70 and +70 mV) and a reversal potential of 0.0±0.4 mV, which was indistinguishable from that of the prototypical TRPV1 agonist capsaicin. Although piperine was a less potent agonist (EC50=37.9±1.9 μM) than capsaicin (EC50=0.29±0.05 μM), it demonstrated a much greater efficacy (approximately two-fold) at TRPV1. This difference in efficacy did not appear to be related to the proton-mediated regulation of the receptor since a similar degree of potentiation was observed for responses evoked by piperine (230±20%, n=11) or capsaicin (284±32%, n=8) upon acidification to pH 6.5. The effects of piperine upon receptor desensitisation were also unable to explain this effect since piperine resulted in more pronounced macroscopic desensitisation (t1/2=9.9±0.7 s) than capsaicin (t1/2>20 s) and also caused greater tachyphylaxis in response to repetitive agonist applications. Overall, our data suggest that the effects of piperine at human TRPV1 are similar to those of capsaicin except for its propensity to induce greater receptor desensitisation and, rather remarkably, exhibit a greater efficacy than capsaicin itself. These results may provide insight into the TRPV1-mediated effects of piperine on gastrointestinal function.

Abstract

The tropical plant family Piperaceae has provided many past and present civilizations with a source of diverse medicines and food grade spice. The secondary plant compounds that produce these desired qualities function also as chemical defenses for many species in the genus Piper. The compounds with the greatest insecticidal activity are the piperamides. Many studies have shown the effectiveness of Piper spp. extracts for the control of stored products pests and recently studies from our laboratory group have tested the extracts of Piper nigrum, P. guineense and P. tuberculatum against insect pests of the home and garden. These results and those from investigations that examined the biochemical and molecular modes of action of the piperamides singly or in combination will be the focus of this review. The conclusions of our current work with Piperaceae are that Piper extracts offer a unique and useful source of biopesticide material for controlling small-scale insect out-breaks and reducing the likelihood of resistance development when applied as a synergist with other botanical insecticides such as pyrethrum.

Abstract

Dietary constituents (e.g., in grapefruit juice; NaCl) and phytochemicals (e.g., St. John's wort) are important agents modifying drug metabolism and transport and thereby contribute to interindividual variability in drug disposition. Most of these drug-food interactions are due to induction or inhibition of P-glycoprotein and/or CYP3A4. Preliminary data indicate that piperine, a major component of black pepper, inhibits drug-metabolizing enzymes in rodents and increases plasma concentrations of several drugs, including P-glycoprotein substrates (phenytoin and rifampin) in humans. However, there are no direct data whether piperine is an inhibitor of human P-glycoprotein and/or CYP3A4. We therefore investigated the influence of piperine on P-glycoprotein-mediated, polarized transport of digoxin and cyclosporine in monolayers of Caco-2 cells. Moreover, by using human liver microsomes we determined the effect of piperine on CYP3A4-mediated formation of the verapamil metabolites D-617 and norverapamil. Piperine inhibited digoxin and cyclosporine A transport in Caco-2 cells with IC50 values of 15.5 and 74.1 microM, respectively. CYP3A4-catalyzed formation of D-617 and norverapamil was inhibited in a mixed fashion, with Ki values of 36 +/- 8 (liver 1)/49 +/- 6 (liver 2) and 44 +/- 10 (liver 1)/77 +/- 10 microM (liver 2), respectively. In summary, we showed that piperine inhibits both the drug transporter P-glycoprotein and the major drug-metabolizing enzyme CYP3A4. Because both proteins are expressed in enterocytes and hepatocytes and contribute to a major extent to first-pass elimination of many drugs, our data indicate that dietary piperine could affect plasma concentrations of P-glycoprotein and CYP3A4 substrates in humans, in particular if these drugs are administered orally.

Abstract

Curcuminoid extract and piperine are being evaluated for beneficial effects in Alzheimer's disease, among other intractable disorders. Consequently, we studied the potential for herb-drug interactions involving cytochrome P450 (P450), UDP-glucuronosyltransferase (UGT), and sulfotransferase (SULT) enzymes. The curcuminoid extract inhibited SULT > CYP2C19 > CYP2B6 > UGT > CYP2C9 > CYP3A activities with IC50 values ranging from 0.99 +/- 0.04 to 25.3 +/- 1.3 microM, whereas CYP2D6, CYP1A2, and CYP2E1 activities were less affected (IC50 values > 60 microM). Inhibition of CYP3A activity by curcuminoid extract was consistent with competitive inhibition (Ki = 11.0 +/- 1.3 microM), whereas inhibition of both CYP2C9 and CYP2C19 activities were consistent with mixed competitive-noncompetitive inhibition (10.6 +/- 1.1 and 7.8 +/- 0.9 microM, respectively). Piperine was a relatively selective noncompetitive inhibitor of CYP3A (IC50 5.5 +/- 0.7 microM, Ki = 5.4 +/- 0.3 microM) with less effect on other enzymes evaluated (IC50 > 29 microM). Curcuminoid extract and piperine inhibited recombinant CYP3A4 much more potently (by >5-fold) than CYP3A5. Pure synthetic curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) were also evaluated for their effects on CYP3A, CYP2C9, UGT, and SULT activities. All three curcuminoids had similar effects on CYP3A, UGT, and SULT activity, but demethoxycurcumin (IC50 = 8.8 +/- 1.2 microM) was more active against CYP2C9 than either curcumin or bisdemethoxycurcumin (IC50 > 50 microM). Based on these data and expected tissue concentrations of inhibitors, we predict that a p.o. administered curcuminoid/piperine combination is most likely to inhibit CYP3A, CYP2C9, UGT, and SULT metabolism within the intestinal mucosa.

Mulberry 1-deoxynojirimycin (DNJ), a potent glucosidase inhibitor, has been hypothesized to be beneficial for the suppression of abnormally high blood glucose levels and thereby prevention of diabetes mellitus. However, DNJ contents in commercial mulberry products were as low as about 0.1% (100 mg/100 g of dry product), implying that the bioavailability of DNJ might not be expected. We carried out studies in two directions: (1) production of food-grade mulberry powder containing a maximally high DNJ content; (2) determination of the optimal dose of the DNJ-enriched powder for the suppression of the postprandial blood glucose through clinical trials. The following method was used: (1) DNJ concentrations in mulberry leaves from different cultivars, harvest seasons, and leaf locations were determined using hydrophilic interaction chromatography with evaporative light scattering detection. (2) Healthy volunteers received 0, 0.4, 0.8, and 1.2 g of DNJ-enriched powder (corresponding to 0, 6, 12, and 18 mg of DNJ, respectively), followed by 50 g of sucrose. Before and 30-180 min after the DNJ/sucrose administration, plasma glucose and insulin were determined. The following results were obtained: (1) Young mulberry leaves taken from the top part of the branches in summer contained the highest amount of DNJ. After optimization of the harvesting and drying processes for young mulberry leaves (Morus alba L. var. Shin ichinose), DNJ-enriched powder (1.5%) was produced. (2) A human study indicated that the single oral administration of 0.8 and 1.2 g of DNJ-enriched powder significantly suppressed the elevation of postprandial blood glucose and secretion of insulin, revealing the physiological impact of mulberry DNJ (effective dose and efficacy in humans). This study suggests that the newly developed DNJ-enriched powder can be used as a dietary supplement for preventing diabetes mellitus.

Background: High sugar and refined carbohydrate intake is associated with weight gain, increased incidence of diabetes and is linked with increased cardiovascular mortality. Reducing the health impact of poor quality carbohydrate intake is a public health priority. Reducose, a proprietary mulberry leaf extract (ME), may reduce blood glucose responses following dietary carbohydrate intake by reducing absorption of glucose from the gut.

Methods: A double-blind, randomised, repeat measure, phase 2 crossover design was used to study the glycaemic and insulinaemic response to one reference product and three test products at the Functional Food Centre, Oxford Brooks University, UK. Participants; 37 adults aged 19-59 years with a BMI ≥ 20kg/m2 and ≤ 30kg/m2. The objective was to determine the effect of three doses of mulberry-extract (Reducose) versus placebo on blood glucose and insulin responses when co-administered with 50g maltodextrin in normoglycaemic healthy adults. We also report the gastrointestinal tolerability of the mulberry extract.

Results: Thirty-seven participants completed the study: The difference in the positive Incremental Area Under the Curve (pIAUC) (glucose (mmol / L x h)) for half, normal and double dose ME compared with placebo was -6.1% (-18.2%, 5.9%; p = 0.316), -14.0% (-26.0%, -2.0%; p = 0.022) and -22.0% (-33.9%, -10.0%; p<0.001) respectively. The difference in the pIAUC (insulin (mIU / L x h)) for half, normal and double dose ME compared with placebo was -9.7% (-25.8%, 6.3%; p = 0.234), -23.8% (-39.9%, -7.8%; p = 0.004) and -24.7% (-40.8%, -8.6%; p = 0.003) respectively. There were no statistically significant differences between any of the 4 groups in the odds of experiencing one or more gastrointestinal symptoms (nausea, abdominal cramping, distension or flatulence).

Conclusions: Mulberry leaf extract significantly reduces total blood glucose rise after ingestion of maltodextrin over 120 minutes. The pattern of effect demonstrates a classical dose response curve with significant effects over placebo. Importantly, total insulin rises were also significantly suppressed over the same time-period. There were no statistically significant differences between any of the treatment groups (including placebo) in the odds of experiencing one or more gastrointestinal symptoms. Mulberry extract may have multiple modes of action and further studies are necessary to evaluate ME as a potential target for the prevention of type 2 diabetes and the regulation of dysglycaemia.

Non-communicable diseases (NCDs) are becoming an increasingly important health concern due to a rapidly ageing global population. The fastest growing NCD, type 2 diabetes mellitus (T2DM), is responsible for over 2 million deaths annually. Lifestyle changes, including dietary changes to low glycemic response (GR) foods, have been shown to reduce the risk of developing T2DM. The aim of this study was to investigate whether three different doses of Reducose®, a mulberry leaf extract, could lower the GR and insulinemic responses (IR) to a full meal challenge in healthy individuals. A double-blind, randomised, placebo-controlled, repeat-measure, crossover design trial was conducted by the Oxford Brookes Centre for Nutrition and Health; 37 healthy individuals completed the study. Participants consumed capsules containing either 200 mg, 225 mg, 250 mg Reducose® or placebo before a test meal consisting of 150 g white bread and egg mayo filler. Capillary blood samples were collected at 15-min intervals in the first hour and at 30-min intervals over the second and third hours to determine glucose and plasma insulin levels. The consumption of all three doses of Reducose® resulted in significantly lower blood glucose and plasma insulin levels compared to placebo. All three doses of Reducose® (200 mg, 225 mg, 250 mg) significantly lowered glucose iAUC 120 by 30% (p = 0.003), 33% (p = 0.001) and 32% (p = 0.002), respectively, compared with placebo. All three doses of Reducose® (200 mg, 225 mg, 250 mg) significantly lowered the plasma insulin iAUC 120 by 31% (p = 0.024), 34% (p = 0.004) and 38% (p < 0.001), respectively. The study demonstrates that the recommended dose (250 mg) and two lower doses (200 mg, 225 mg) of Reducose® can be used to help lower the GR and IR of a full meal containing carbohydrates, fats and proteins.

Background: There are many benefits of maintaining healthy blood glucose levels, and studies have shown that lifestyle changes such as changes to diet can successfully restore normoglycaemia in participants with dysglycaemia. Significant health-related lifestyle changes are often difficult to implement and functional ingredients that can reduce glycaemic and insulaemic responses may help at risk populations. The aim of this study was to investigate whether a mulberry leaf extract could lower the glycaemic and insulinaemic responses to 75 g sucrose in healthy individuals.

Methods: A double-blind, randomised, placebo-controlled, crossover design trial was conducted by the Oxford Brookes Centre for Nutrition and Health. Thirty-eight participants were recruited into the trial and, after an overnight fast, were given 75 g sucrose + white mulberry leaf extract, or 75 g sucrose alone. Capillary blood samples were collected at 15-min intervals in the first hour and at 30-min intervals over the second hour to determine glucose and plasma insulin levels. Data analysis was conducted using a paired samples T test or a Wilcoxon signed rank test.

Results: The addition of mulberry leaf extract to sucrose resulted in a significantly lower glycaemic response and insulinaemic response compared to a matched placebo (sucrose alone). The change in blood glucose measurements were significantly lower at 15 min (p < 0.001), 30 min (p < 0.001), 45 min (p = 0.008), and 120 min (p < 0.001) and plasma insulin measurements were significantly lower at 15 min (p < 0.001), 30 min (p < 0.001), 45 min (p < 0.001), 60 min (p = 0.001) and 120 min (p < 0.001). The glucose iAUC (− 42%, p = 0.001), insulin iAUC (− 40%, p < 0.001), peak glucose (− 40.0%, p < 0.001) and peak insulin (− 41%, p < 0.001) from baseline were significantly lower for white mulberry leaf extract compared with the placebo. White mulberry leaf extract was well tolerated and there were no reported adverse events.

Conclusions: Mulberry leaf extract can be used as part of lifestyle changes that may lead to healthy blood glucose levels.

Trial registration: ISRCTN99601810 (23 October 2020, retrospectively registered).

In this study, the influences of mulberry leaf extract (MLE) addition on the physicochemical properties including the specific volume, texture and sensory features of white bread (WB) were evaluated by the sensory analysis technology. A double-blind, randomised, repeat-measure design was used to study the impact of MLE addition on the postprandial blood glucose response as well as the satiety index of WB. Results showed that the addition of MLE showed no significant effects on the physicochemical properties of WB except for the slight changes of color and bitterness. The addition of MLE significantly reduced the total blood glucose rise after ingestion of WB over 120 minutes, and reduced the GI value of WB in a dose-effect relationship. When the concentration of MLE reached 1.5 g per 100 g available carbohydrate, the GI value of WB could be reduced from 77 to 43. This study provides important information in terms of the appropriateness of MLE when added to more complex real food, the dose-dependent relationship could supply a reference for the application of MLE.

Worth being precise about what the trials measured. The effect is per meal. At label dose, mulberry leaf extract cuts the glucose curve after a carbohydrate meal by something like 30 to 40%, which is not modest at all. But the one trial that supplemented for 12 weeks found no change in fasting glucose, HbA1c, or glycated albumin. So DNJ blunts the meal in front of you. It does not reorganise your metabolism, and anyone selling you the second thing is selling past the evidence.

To je, naravno, najbolji mogući scenarij. Znatno češće smo došli i bilješke spalili, one koji su ih pisali porobili ili pobili, a zatim se stražnjicom naprijed spotaknuli o ono što su autohtoni narodi znali tisućljećima i otkriće prodali kao svoje. Pitajte Ande, koji su Europljane naučili što može kora kininovca (izvor antimalarika kinina)...