Phenolics and condensed tannins of high altitude Pteridium arachnoideum in relation to sunlight exposure, elevation, and rain regime

A Systematic Review of Cardio-Metabolic Properties of Lonicera caerulea L

In the light of growing concerns faced by Western societies due to aging, natality decline, and epidemic of cardio-metabolic diseases, both preventable and treatable, new and effective strategical interventions are urgently needed in order to decrease their socio-economical encumbrance. The recent focus of research has been redirected towards investigating the potential of haskap (Lonicera caerulea L.) as a novel functional food or superfruit. Therefore, our present review aims to highlight the latest scientific proofs regarding the potential of Lonicera caerulea L. (LC), a perennial fruit-bearing plant rich in polyphenols, in reversing cardio-metabolic dysfunctions. In this regard, a systematic search on two databases (PubMed and Google Scholar) from 1 January 2016 to 1 December 2023 was performed, the keyword combination being Lonicera caerulea L. AND the searched pharmacological action, with the inclusion criteria consisting of in extenso original articles, written in English. The health-enhancing characteristics of haskap berries have been examined through in vitro and in vivo studies from the 35 included original papers. Positive effects regarding cardiovascular diseases and metabolic syndrome have been assigned to the antioxidant activity, hypolipidemic and hypoglycemic effects, as well as to the hepatoprotective and vasoprotective potential. Latest advances regarding LCF mechanisms of action are detailed within this review as well. All these cutting-edge data suggest that this vegetal product would be a good candidate for further clinical studies.

Urban Flora Riches: Unraveling Metabolic Variation Along Altitudinal Gradients in Two Spontaneous Plant Species

Using resilient, self-sustaining plants in urban green spaces enhances environmental and cultural benefits and reduces management costs. We assessed two spontaneous plant species, Linaria vulgaris Mill. and Cichorium intybus L., in four sites from the surrounding urban areas, ranging in altitude from 78 to 1040 m. Protection against UV-B radiation is crucial for plants at higher altitudes, guiding our focus on UV-visible absorption spectra, fluorometric emission spectra, secondary metabolite accumulation, and pigment dynamics in leaves. Our findings revealed a slight increase in UV-absorbing compounds with altitude and species-specific changes in visible spectra. The UV-emission of fluorochromes decreased, while red emission increased with altitude but only in chicory. Polyphenols and flavonoids showed a slight upward trend with altitude. Divergent trends were observed in condensed tannin accumulation, with L. vulgaris decreasing and C. intybus increasing with altitude. Additionally, chicory leaves from higher altitudes (792 and 1040 m) contained significantly lower triterpene concentrations. In L. vulgaris, chlorophyll pigments and carotenoids varied with sites, contrasting with UV absorbance variations. For C. intybus, pigment variation was similar to absorbance changes in the UV and VIS range, except at the highest altitude. These observations provide valuable insights into species-specific strategies for adapting to diverse environmental contexts.

Exploring morphological variability, in vitro antioxidant potential, and HR-LCMS phytochemical profiling of Phlomis cashmeriana Royle ex Benth. across different habitats of Kashmir Himalaya

Phytochemicals are broadly acknowledged for their health-promoting effects owing to the fact of their capacity to counteract free radicals (e.g., superoxide anion radical, hydroxyl radical, hydroperoxyl radical, singlet oxygen, hypochlorite, and nitric oxide) and shield against oxidative stress induced by environmental factors. This study aimed to investigate the relationship between altitude, morphology, soil parameters, in vitro antioxidant potential and phytochemical composition of Phlomis cashmeriana collected from four different locations of Kashmir Himalaya characterized by diverse habitats and elevations. Various factors, such as extraction method, solvent polarity, and habitat conditions, can impact the quantity and efficacy of phytochemicals in plants. The aim of current study was to analyze phytochemical composition and antioxidant activity of P. cashmeriana, an important medicinal plant found in the Kashmir Himalaya region. The antioxidant activity was accessed using several assays and the plant populations were selected based on their diverse habitat features and altitudes. HR-LCMS was conducted for both below-ground and above-ground parts. Some important compounds such as, catechin, vinainsenoside, acutilobin, and kaempferol were reported for the first time from P. cashmeriana. Results showed that methanol was the most efficient solvent for extracting phytochemicals. During the current study, it was also found that the below-ground parts exhibited superior antioxidant activity compared to the above-ground parts. Notably, Site IV demonstrated the highest antioxidant potential; a positive correlation between altitude and antioxidant activity was also found. In conclusion, present research identified specific elite populations having highest antioxidant potential and are well-suited for large-scale cultivation of P. cashmeriana.

Genetic divergence along a climate gradient shapes chemical plasticity of a foundation tree species to both changing climate and herbivore damage

Climate change is threatening the persistence of many tree species via independent and interactive effects on abiotic and biotic conditions. In addition, changes in temperature, precipitation, and insect attacks can alter the traits of these trees, disrupting communities and ecosystems. For foundation species such as Populus, phytochemical traits are key mechanisms linking trees with their environment and are likely jointly determined by interactive effects of genetic divergence and variable environments throughout their geographic range. Using reciprocal Fremont cottonwood (Populus fremontii) common gardens along a steep climatic gradient, we explored how environment (garden climate and simulated herbivore damage) and genetics (tree provenance and genotype) affect both foliar chemical traits and the plasticity of these traits. We found that (1) Constitutive and plastic chemical responses to changes in garden climate and damage varied among defense compounds, structural compounds, and leaf nitrogen. (2) For both defense and structural compounds, plastic responses to different garden climates depended on the climate in which a population or genotype originated. Specifically, trees originating from cool provenances showed higher defense plasticity in response to climate changes than trees from warmer provenances. (3) Trees from cool provenances growing in cool garden conditions expressed the lowest constitutive defense levels but the strongest induced (plastic) defenses in response to damage. (4) The combination of hot garden conditions and simulated herbivory switched the strategy used by these genotypes, increasing constitutive defenses but erasing the capacity for induction after damage. Because Fremont cottonwood chemistry plays a major role in shaping riparian communities and ecosystems, the effects of changes in phytochemical traits can be wide reaching. As the southwestern US is confronted with warming temperatures and insect outbreaks, these results improve our capacity to predict ecosystem consequences of climate change and inform selection of tree genotypes for conservation and restoration purposes.

Mass Spectrometry Metabolomics and Feature-Based Molecular Networking Reveals Population-Specific Chemistry in Some Species of the Sceletium Genus

The Sceletium genus has been of medicinal importance in southern Africa for millennia and Sceletium tortuosum (Aizoaceae), one of eight species in the genus has gained pharmaceutical importance as an anxiolytic and anti-depressant due to the presence of mesembrine alkaloids. S. tortuosum is used for the manufacture of herbal teas, dietary supplements and other phytopharmaceutical products. This study aimed to provide a metabolomic characterization of S. tortuosum and its sister species as these are not easy to distinguish using morphology alone. Plant samples were thus collected from various locations in the succulent Karoo (South Africa) and analyzed through liquid chromatography-mass spectrometry (LC-MS), using MS^E fragmentation as a putative tool for chemical identities. Metabolomics-based analyses in combination with molecular networking were able to distinguish between the four species of Sceletium based on the presence of 4-(3,4-dimethyoxyphenyl)-4-[2-acetylmethlamino)ethyl]cyclohexanone (m/z 334.2020; RT 6.60 min), mesembrine (m/z 290.1757; RT 5.10 min) and 4'-O-demethylmesembrenol (m/z 276.1597; RT 4.17 min). Metabolomic profiles varied according to the different localities and metabolites occurred at variable quantitative levels in Sceletium ecotypes. Molecular networking provided the added advantage of being able to observe mesembrine alkaloid isomers and coeluting metabolites (from the joubertiamine group) that were difficult to discern without this application. By combining high-throughput metabolomics together with global and feature based-molecular networking, a powerful metabolite profiling platform that is able to discern chemical patterns within and between populations was established. These techniques were able to reveal chemotaxonomic relationships and allowed for the discovery of chemical markers that may be used as part of monitoring protocols during the manufacture of phytopharmaceutical and dietary products based on Sceletium.

Gas chromatography-mass spectrometry (GC-MS) profiling reveals substantial metabolome diversity in seabuckthorn (Hippophae rhamnoides L.) berries originating from different geographical regions in the Indian Himalayas

INTRODUCTION

Seabuckthorn (Hippophae rhamnoides L.) is a high-altitude plant with immense medicinal, nutritional, and therapeutic value. Earlier studies have documented the presence of various useful bioactive substances in this species; however, comprehensive metabolome profiling of seabuckthorn berries originating from different regions of the Indian Himalayas has not been undertaken.

OBJECTIVE

Metabolomic profiling of seabuckthorn berries originating from different geographical sites in the Himachal Pradesh and Jammu & Kashmir regions of the Indian Himalayas was performed by using gas chromatography-mass spectrometry.

MATERIALS AND METHODS

The GC-MS metabolome profiles of seabuckthorn berries collected from different sites (altitude 1,400-4,270 m; average temperature 8°C-27°C) were subjected to multivariate analysis following principal component analysis and hierarchical clustering analysis.

RESULTS

The GC-MS results showed substantial variability for berry metabolites, including fatty acids, alkyl ethers, and alkyl esters. Fatty acids and their esters were mainly responsible for the variation in the berry metabolome. The metabolite expression profile heat map revealed two distinct groups of seabuckthorn berries originating from Himachal Pradesh (Lahaul and Spiti) and Jammu & Kashmir (Leh, Nubra, and Kargil), the former showing higher expression of metabolites. Interestingly, a strong negative association existed between altitude and the amounts of metabolites such as amides, alkyl esters, alcohols, sugars, and sugar esters. In contrast, temperature showed a strong positive association with ketone and alkyl ether levels.

CONCLUSION

GC-MS profiling provides important phytochemical indicators to distinguish between seabuckthorn berries from different geographical sites. Our metabolome profiling analysis generated valuable information that will be useful in the formulation of various seabuckthorn products, benefiting farmers and industries.

Quality evaluation of wild germplasm of Chinese prickly ash (Zanthoxylum bungeanum Maxim) from Qinling mountains at different elevations based on HPLC-fingerprint

Wild Chinese prickly ash resources provide a valuable genetic resource for Zanthoxylum bungeanum Maxim improvement and breeding. The Qinling Mountains was an abundant source for wild Chinese prickly ash. In this study, the phenolic and flavonoid compounds of wild germplasm resources from different altitudes and six cultivated varieties were analyzed by high performance liquid chromatography (HPLC). The chromatograms of them were essentially consistent, although their chemical composition contents were greatly different. The thirty samples were divided into three categories through the hierarchical clustering analysis. Catechin, hyperoside and quercitrin were considered to be key compounds for the quality evaluation, and by contrast, the wild samples with an altitude of 2300±50 m (Group IV) had the highest content of key compounds, and presented stronger antioxidant activity and antibacterial ability, indicating that these wild samples could be identified as the excellent breeding resources. This is the first time to evaluate the quality of wild Chinese prickly ash at different altitudes in Qinling Mountains. These excellent wild germplasm resources provided substantial potential accessions for use directly in Chinese prickly ash breeding programs.

Selected Extracts from High Mountain Plants as Potential Sunscreens with Antioxidant Capacity

The photoprotective and antioxidant activities of extracts of six species of plants collected in a high mountain ecosystem at 3150 m.a.s.l. were evaluated. In vitro photoprotection according to UVA-UVB absorption spectrum, Sun Protection Factor (SPF), UVA Protection Factor (UVAPF), (critical wavelength) λ_c and UVA/UVB Ratio were assessed. Also, the antioxidant activity was determined using the DPPH radical assay and the inhibition of lipid peroxidation in methyl linoleate (MeLo). Total anthocyanins content (TAC) and total polyphenolic content (TPC) were evaluated. Among the extracts evaluated, the extract of B. antioquensis, an endemic plant of Colombia, showed a significant photoprotection against UVA-UVB range, with SPF values of 15 ± 2 and UVAPF of 7 ± 1, λ_c : 378, UVA/UVB Ratio: 0.78. Furthermore, this extract presented an excellent antioxidant activity, with EC₅₀ of 0.17 ± 0.04 g of dry extract/mmol DPPH, a value of TPC of 464 ± 9 mg gallic acid equivalents (GAE)/g dry extract and significant inhibition of MeLo peroxidation. The results suggest that the extract of B. antioquensis has the best quality to be a source of new UV filters, with a broad spectrum of protection and antioxidant properties.

Application of Polypodiopsida Class in Nanotechnology-Potential towards Development of More Effective Bioactive Solutions

The area of phytosynthesized nanomaterials is rapidly developing, with numerous studies being published yearly. The use of plant extracts is an alternative method to reduce the toxic potential of the nanomaterials and the interest in obtaining phytosynthesized nanoparticles is usually directed towards accessible and common plant species, ferns not being explored to their real potential in this field. The developed nanoparticles could benefit from their superior antimicrobial and antioxidant properties (compared with the nanoparticles obtained by other routes), thus proposing an important alternative against health care-associated and drug-resistant infections, as well as in other types of applications. The present review aims to summarize the explored application of ferns in nanotechnology and related areas, as well as the current bottlenecks and future perspectives, as emerging from the literature data.

Higher Elevations Tend to Have Higher Proportion of Plant Species With Glandular Trichomes

Glandular trichomes are well known to participate in plant chemical and physical defenses against herbivores, especially herbivorous insects. However, little is known about large-scale geographical patterns in glandular trichome occurrence. Herbivory pressure is thought to be higher at low elevations because of warmer and more stable climates. We therefore predicted a higher proportion of species with glandular trichomes at low elevations than at higher elevations. We compiled glandular trichome data (presence/absence) for 6,262 angiosperm species from the Hengduan Mountains (a global biodiversity hotspot in southwest China). We tested the elevational gradient (800-5,000 m a.s.l.) in the occurrence of plant species with glandular trichomes, and its correlations with biotic (occurrence of herbivorous insects) and abiotic factors, potentially shaping the elevational gradient in the occurrence of glandular trichomes. We found a significantly positive relationship between elevation and the occurrence of glandular trichomes, with the proportion of species having glandular trichomes increasing from 11.89% at 800 m a.s.l. to 17.92% at above 4,700 m. This cross-species relationship remained significant after accounting for phylogenetic relationships between species. Herbivorous insect richness peaked at mid-elevations and its association with the incidence of glandular trichomes was weak. Mean annual temperature was the most important factor associated negatively with glandular trichomes. Our results do not support the hypothesis that plant defenses decrease with increasing elevation. In contrast, a higher proportion of plant species with glandular trichome toward higher elevations is observed. Our results also highlight the importance of considering the simultaneous influences of biotic and abiotic factors in testing geographical variation in multifunctional plant defenses.

Epicormic bud protection traits vary along a latitudinal gradient in a neotropical savanna

Regrowth via production of epicormic shoots is an important strategy for many woody plants after environmental disturbances such as fire, drought, and herbivory. Populations spreading across a broad latitudinal gradient offer opportunities to investigate if essential traits vary with heterogenous environmental conditions, such as in savanna ecosystems. This information can help us predict plant responses to climate change. Here, we evaluated if epicormic bud protection traits varied among populations of three focal savanna species (Miconia albicans, Solanum lycocarpum, and Zeyheria montana) that have a wide distribution and grow under variable climatic conditions. We randomly sampled 225 individuals over five spatially independent sites (7°, 10°, 15°, 18°, and 24° S) in Brazil, totaling 15 individuals per species per area. We analyzed anatomical transverse sections of five buds per species per area to assess the relative area occupied by crystal and phenolic idioblasts, the thickness of the trichome boundary layer, and to test if these traits were associated with climatic conditions. The buds were protected by cataphylls and composed of a variable number of undeveloped leaves enveloping the shoot apex. For M. albicans, we found an association between maximum temperature and both phenolic idioblasts and trichome boundary layer, but no association with crystal idioblasts. In S. lycocarpum, only the trichome boundary layer was associated with maximum temperature plus high radiation. Z. montana showed no variation. Combination of two or more traits can lead to the development of adaptative strategies to different climatic conditions. We present for the first time an analysis of epicormic bud traits in plant populations occurring in an extensive latitudinal gradient and shed light on how maximum temperature is associated with these traits, contributing to a better understanding of plant resprouting capabilities in widespread savanna plant species.

Non-target metabolomics revealed the differences between Rh. tanguticum plants growing under canopy and open habitats

BACKGROUND

Rheum tanguticum (Rh. tanguticum) is an important traditional Chinese medicine plant, "Dahuang", which contains productive metabolites and occupies wide habitats on the Qinghai-Tibet plateau. Plants occupying wide habitats usually vary in phenotypes such as in morphology and metabolism, thereby developing into different ecotypes. Under canopy and open habitats are a pair of dissimilar habitats which possess Rh. tanguticum plants. However, few studies have focused on the effect of habitats on Rh. tanguticum growth, particularly combining morphological and metabolic changes. This study focused on Rh. tanguticum plants growing in under canopy and open habitats where morphology and metabolism changes were quantified using non-target metabolism methods.

RESULTS

The obtained results indicated that the two dissimilar habitats led to Rh. tanguticum developing into two distinct ecotypes where the morphology and metabolism were simultaneously changed. Under canopy habitats bred morphologically smaller Rh. tanguticum plants which had a higher level of metabolites (22 out of 31) which included five flavonoids, four isoflavonoids, and three anthracenes. On the other hand, the open habitats produced morphologically larger Rh. tanguticum plants having a higher level of metabolites (9 out of 31) including four flavonoids. 6 of the 31 metabolites were predicted to have effect targets, include 4 represent for under canopy habitats and 2 for open habitats. Totally, 208 targets were connected, among which 42 were communal targets for both under canopy and open habitats represent compounds, and 100 and 66 were unique targets for under canopy superior compounds and open habitats superior compounds, respectively. In addition, aloe-emodin, emodin, chrysophanol, physcion, sennoside A and sennoside B were all more accumulated in under canopy habitats, and among which aloe-emodin, emodin, chrysophanol and physcion were significantly higher in under canopy habitats.

CONCLUSIONS

This study determined that Rh. tanguticum growing in under canopy and in open habitats developed into two distinct ecotypes with morphological and metabolic differences. Results of network pharmacology study has indicated that "Dahuang" coming from different habitats, such as under canopy and open habitats, are different in effect targets and thus may have different medicinal use. According to target metabolomics, under canopy habitats may grow better "Dahuang".

Phytochemical characterization and effects on cell proliferation of Pinus nigra Arn. bark

Pinus nigra Arn. bark extracts from Mokra gora (MG) and Tara mountains were analyzed with regard to their polyphenolic profile and antioxidative and antiproliferative activity. The ethanol extract from MG showed the highest phenolic, flavonoid, tannin, and proanthocyanidin content when compared with the acetone and methanol extracts from both sites. The same extract exhibited the highest ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and ferric reducing antioxidant power (FRAP) radical scavenging ability and total antioxidant activity (TAA). On the basis of high-performance liquid chromatography analysis, catechin, caffeic, syringic, p-coumaric, and ferulic acids were predominantly present in the MG extracts. The ethanol extract from MG was rich in syringic acid, epicatechin and its derivatives, and ferulic acid and its derivatives. The bark extracts also exerted a high cytotoxic bioactivity against all evaluated cell lines (HeLa, MCF7, HT-29, and MRC-5). The antiproliferative activity of P. nigra bark is probably related to the ferulic acid content and its synergistic activity to caffeic acid and taxifolin. The antioxidative role of the presented phenols was confirmed through the obtained significant linear correlation between the total phenolic content and DPPH (r = .934) as well as the FRAP% of the extracts (r = .948). Also, the TAA significantly depended on the proanthocyanidins (r = .902) and tannin contents (r = .914). The composition of the presented compounds could be related to promising antioxidant and antiproliferative efficacy of MG bark.

Variability in morphology, phytochemicals, and antioxidants in Polygonatum verticillatum (L.) All. populations under different altitudes and habitat conditions in Western Himalaya, India

Polygonatum verticillatum (L.) All. is one among eight species of Astavarga group of plants known for its vitality strengthening properties and used in different herbal formulations. However, systematic investigation on morphology and antioxidant phytochemicals in relation to different environmental variables like altitude and habitat conditions is poorly available. The present study reveals significant (p < 0.05) differences in structural and functional attributes among sixteen different populations of P. verticillatum in West Himalaya. Among the different populations, plants growing in moist habitat and oak forest exhibited maximum plant height, leaf number, biomass and phytochemical content (total phenolics, tannin, and flavonol). Antioxidant activity using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) positively (p < 0.05) correlated with altitude. Presence of strong antioxidant and DNA damage prevention activity of the species validate its use as vitality strengthening and anti-aging properties. Identified suitable altitude, habitat conditions, and forest types can be utilized for reintroduction of species in to suitable agro-climatic condition. This will also help in obtaining higher quality produce and management practices for conservation of this species.

Temporal, Plant Part, and Interpopulation Variability of Secondary Metabolites and Antioxidant Activity of Inula helenium L

Variations in abiotic environmental factors have significant effects on quantity and quality of secondary metabolites, which is particularly important for plant species that possess biologically active compounds. The purpose of this study is determination of the total phenolic content, flavonoid concentration, and antioxidant activity of the different parts of Inula helenium L. (Asteraceae) sampled from different populations and in different time periods. The amounts obtained for the total phenolics varied from 16.73 to 89.85 mg of gallic acid (GA)/g. The concentration of flavonoids ranged from 9.32 to 376.22 mg of rutin (Ru)/g. The IC₅₀ values of antioxidant activity determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical method varied from 161.60 to 1563.02 μg/ml. The inflorescence and roots possessed high concentration of phenolic compounds and significant antioxidant activity, while leaves contained the highest concentration of flavonoids. Additionally, the quantity of the phenolics, as well as antioxidant activity, significantly varied among the different populations due to different impacts of environmental factors. This research showed that I. helenium represents an abundant source of bioactive substances, and that the quantity of these compounds greatly differs among the different populations as well as in the same populations regarding the different time periods as well as plant parts.

Who will win where and why? An ecophysiological dissection of the competition between a tropical pasture grass and the invasive weed Bracken over an elevation range of 1000 m in the tropical Andes

In tropical agriculture, the vigorously growing Bracken fern causes severe problems by invading pastures and out-competing the common pasture grasses. Due to infestation by that weed, pastures are abandoned after a few years, and as a fatal consequence, the biodiversity-rich tropical forest is progressively cleared for new grazing areas. Here we present a broad physiological comparison of the two plant species that are the main competitors on the pastures in the tropical Ecuadorian Andes, the planted forage grass Setaria sphacelata and the weed Bracken (Pteridium arachnoideum). With increasing elevation, the competitive power of Bracken increases as shown by satellite data of the study region. Using data obtained from field measurements, the annual biomass production of both plant species, as a measure of their competitive strength, was modeled over an elevational gradient from 1800 to 2800 m. The model shows that with increasing elevation, biomass production of the two species shifts in favor of Bracken which, above 1800 m, is capable of outgrowing the grass. In greenhouse experiments, the effects on plant growth of the presumed key variables of the elevational gradient, temperature and UV radiation, were separately analyzed. Low temperature, as well as UV irradiation, inhibited carbon uptake of the C4-grass more than that of the C3-plant Bracken. The less temperature-sensitive photosynthesis of Bracken and its effective protection from UV radiation contribute to the success of the weed on the highland pastures. In field samples of Bracken but not of Setaria, the content of flavonoids as UV-scavengers increased with the elevation. Combining modeling with measurements in greenhouse and field allowed to explain the invasive growth of a common weed in upland pastures. The performance of Setaria decreases with elevation due to suboptimal photosynthesis at lower temperatures and the inability to adapt its cellular UV screen.

Influence of light quality on growth, secondary metabolites production and antioxidant activity in callus culture of Rhodiola imbricata Edgew

Rhodiola imbricata is a rare medicinal herb well-known for its adaptogenic and antioxidant properties due to the presence of a diverse array of secondary metabolites, including phenylethanoids and phenylpropanoids. These secondary metabolites are generating considerable interest due to their potential applications in pharmaceutical and nutraceutical industries. The present study investigated the influence of light quality on growth, production of industrially important secondary metabolites and antioxidant activity in callus cultures of Rhodiola imbricata. Callus cultures of Rhodiola imbricata were established under different light conditions: 100% red, 100% blue, 100% green, RGB (40% red: 40% green: 20% blue) and 100% white (control). The results showed that the callus cultures grown under red light accumulated maximum amount of biomass (7.43 g/l) on day 21 of culture, as compared to other light conditions. Maximum specific growth rate (0.126 days^-1) and doubling time (132.66 h) was observed in callus cultures grown under red light. Reverse phase-high performance liquid chromatographic (RP-HPLC) analysis revealed that the callus cultures exposed to blue light accumulated maximum amount of Salidroside (3.12 mg/g DW) on day 21 of culture, as compared to other light conditions. UV-Vis spectrophotometric analysis showed that the callus cultures exposed to blue light accumulated maximum amount of total phenolics (11.84 mg CHA/g DW) and total flavonoids (5.53 mg RE/g DW), as compared to other light conditions. Additionally, callus cultures grown under blue light displayed enhanced DPPH free radical scavenging activity (53.50%). Callus cultures grown under different light conditions showed no significant difference in ascorbic acid content (11.05-13.90 mg/g DW) and total antioxidant capacity (27.37-30.17 mg QE/g DW). The correlation analysis showed a positive correlation between total phenolic content and DPPH free radical scavenging activity in callus cultures (r = 0.85). Taken together, these results demonstrate the remarkable potential of light quality on biomass accumulation and production of industrially important secondary metabolites in callus cultures of Rhodiola imbricata. This study will open new avenues and perspectives towards abiotic elicitation strategies for sustainable growth and enhanced production of bioactive compounds in in-vitro cultures of Rhodiola imbricata.

Impact of edaphic factors and nutrient management on the hepatoprotective efficiency of Carlinoside purified from pigeon pea leaves: An evaluation of UGT1A1 activity in hepatitis induced organelles

Carlinoside is a unique compound well-known for its excellent curative potential in hepatitis. There is a substantial research gap regarding the medicinal use of carlinoside, as its concentrations are greatly variable (depending on locality). We cultivated Cajanus cajan using vermicompost as a major organic amendment at two locations (Sonitpur and Birbhum) with different soil types, but identical climate conditions. Sonitpur soils were richer in soil organic C (SOC), enzyme activation, and N/P content than Birbhum. However, vermi-treatment improved many soil properties (bulk density, water retention, pH, N/P/K, and enzyme activity) to narrow the locational gap in soil quality by 15-28%. We also recorded a many-fold increment in SOC storage capacities in both locations, which was significantly correlated with carlinoside, total phenol, and flavonoid contents in Cajanus leaves. This significantly up-regulated the carlinoside induced expression of the bilirubin-solubilizing UGT1A1enzyme in HepG2 cell and rat liver. Leaf extracts of vermicompost-aided plants could cure hepatitis in affected rat livers and in the HepG2 cell line. Accordingly, vermi-treatment is an effective route for the growth of Cajanus as a cash crop for biomedical applications and can produce a concurrent improvement in soil quality.

Variability of Secondary Metabolites of the Species Cichorium intybus L. from Different Habitats

The principal aim of this paper is to show the influence of soil characteristics on the quantitative variability of secondary metabolites. Analysis of phenolic content, flavonoid concentrations, and the antioxidant activity was performed using the ethanol and ethyl acetate plant extracts of the species Cichorium intybus L. (Asteraceae). The samples were collected from one saline habitat and two non-saline habitats. The values of phenolic content from the samples taken from the saline habitat ranged from 119.83 to 120.83 mg GA/g and from non-saline habitats from 92.44 to 115.10 mg GA/g. The amount of flavonoids in the samples from the saline locality varied between 144.36 and 317.62 mg Ru/g and from non-saline localities between 86.03 and 273.07 mg Ru/g. The IC₅₀ values of antioxidant activity in the samples from the saline habitat ranged from 87.64 to 117.73 μg/mL and from 101.44 to 125.76 μg/mL in the samples from non-saline habitats. The results confirmed that soil types represent a significant influence on the quantitative content of secondary metabolites. The greatest concentrations of phenols and flavonoids and the highest level of antioxidant activity were found in the samples from saline soil. This further corroborates the importance of saline soil as an ecological factor, as it is proven to give rise to increased biosynthesis of secondary metabolites and related antioxidant activity.

UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations

Ongoing changes in Earth's climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280-315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (T_{UV A}) in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which T_{UV A} varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial T_{UV A}, measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8) and non-native (mean = 5.8%; n = 11) species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on T_{UV A}, though woody plants (shrubs and trees) were represented solely by native species whereas herbaceous growth forms (grasses and forbs) were dominated by non-native species. Along an elevation gradient spanning 2600-3800 m, T_{UV A} was variable (mean range = 6.0-11.2%) and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus; however, T_{UV A} was consistently low (3%) and did not vary with elevation in the native V. reticulatum. Results indicate that high levels of UV protection occur in both native and non-native species in this high UV-B tropical alpine environment, and that flexibility in UV screening is a mechanism employed by some, but not all species to cope with varying solar UV-B exposures along elevation gradients.

Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil

The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant’s dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of allelopathy in the dominance processes of this plant in the areas where it occurs.

Impact of Altitudes and Habitats on Valerenic Acid, Total Phenolics, Flavonoids, Tannins, and Antioxidant Activity of Valeriana jatamansi

The changes in total phenolics, flavonoids, tannins, valerenic acid, and antioxidant activity were assessed in 25 populations of Valeriana jatamansi sampled from 1200 to 2775 m asl and four habitat types of Uttarakhand, West Himalaya. Significant (p < 0.05) variations in total phenolics, flavonoids, valerenic acid, and antioxidant activity in aerial and root portions and across the populations were observed. Antioxidant activity measured by three in vitro antioxidant assays, i.e., 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) (ABTS) radical scavenging, 2,2'-diphenyl-1-picryylhydrazyl (DPPH) free radical scavenging, and ferric-reducing antioxidant power (FRAP) assays, showed significant (p < 0.05) differences across the populations. However, no clear pattern was found in phytochemicals across the altitudinal range. Among habitat types, (pine, oak, mixed forest, and grassy land), variation in phytochemical content and antioxidant activity were observed. Equal class ranking, neighbor-joining cluster analysis, and principal component analysis (PCA) identified Talwari, Jaberkhet, Manjkhali, and Khirshu populations as promising sources with higher phytochemicals and antioxidant activity. The results recommended that the identified populations with higher value of phytochemicals and antioxidants can be utilized for mass multiplication and breeding program to meet the domestic as well as commercial demand.

Carbon-nitrogen ratio and in vitro assimilate partitioning patterns in Cyrtanthus guthrieae L

In response to variations in nutritional composition of the growth medium, plants often adjust their metabolism and progressively alter their growth patterns. Carbon (C) and nitrogen (N) constitute the major plant nutritional components influencing plant growth and development patterns. This study examined the growth dynamics and patterns of assimilate partitioning to primary and secondary metabolites in response to varying levels and combinations of C and N in the culture media of Cyrtanthus guthrieae. In vitro callus-derived C. guthrieae plantlets were cultured on solid Murashige and Skoog (MS) media with different concentrations and combinations of C and N. Relative growth rate (RGR) increased proportionally with an increase in C concentrations up to 88 mM sucrose (0.58 d(-1)) beyond which it was hardly influenced by further increases in C. Growth was also significantly favoured in media with high concentrations of N at all C concentrations tested. In C-limited media regimes with growth saturating N conditions, alkaloid accumulation became favoured while polyphenol content increased with an increase in C levels in the medium, a characteristic pattern that appeared to be less influenced by the amount of N. Of the primary metabolites, only proteins showed small significant variations across different media treatments, with starch and soluble sugars increasing proportionately with C levels. In the medium with a high sucrose concentration (175 mM), soluble sugars, amino acids and polyphenols increased markedly, possibly as an adaptive response to the reduced osmotic potential in the media and/or a storage mechanism for excess C and N reserves in the media. From a medicinal perspective, with regard to polyphenolic compounds in C. guthrieae, growth medium conditions that allow for high levels of C pools in the tissue would thus be favourable for the enhanced synthesis of this group of compounds. The medium conditions with 175 mM sucrose and 10.3 mM NH4NO3 gave the highest total polyphenols, flavonoids and proanthocyanidins with a moderate growth rate.

Altitudinal and seasonal changes of phenolic compounds in Buxus sempervirens leaves and cuticles

The variation in the leaf content of phenolic compounds has been related to the UV-B changes of the environment in which plants grow. In this context, we aimed to investigate: a) whether the seasonal and altitudinal changes in the content of phenolic compounds of Buxus sempervirens L. leaves and cuticles could be related to the natural fluctuations in UV-B levels and b) the possible use of specific phenolic compounds as biomarkers of ambient UV-B levels. To achieve these goals we sampled, every three months during one year, leaves of B. sempervirens along an altitudinal gradient. At the lowest and the highest altitudes, we also conducted a UV-exclusion experiment to discern whether the observed changes could be attributed to the natural variation in UV-B. Results show that total phenolic content of leaves was lower in June than in the other sampling dates, which suggests a leaf ontogenic rather than a UV-B effect on the leaf content of these compounds. Regarding the elevational gradient, the overall amount of phenolic acids and neolignan of entire leaves increased with altitude while the total amount of flavonoids in leaf cuticles decreased. However, the lack of a significant effect of our UV-exclusion treatment on the content of these compounds suggests that the observed variations along the altitudinal gradient would respond to other factors rather than to UV-B. Concomitantly, we did not find any phenolic compound in leaves or cuticles of B. sempervirens that could be considered as a biomarker of ambient UV-B levels.

Wild leafy vegetables consumed in Buhera District of Zimbabwe and their phenolic compounds content

A questionnaire was used to gather information on the wild leafy vegetables consumed. The phenolic concentrations were determined by the vanillin, butanol, and tannin binding assays. Seventy-nine traditional vegetables were mentioned by the respondents and 20 of these were classified according to their species. The contents of flavonoids varied from 1.2 mg/g for Cleome gynandra to 8.0 mg/g for Bidens pilosa. The levels of proanthocyanidins ranged from 1.9 mg/g for lettuce to 11.2 mg/g for Bidens pilosa. The tannin contents of the vegetables ranged from 5.7 mg/g for Cleome gynandra to 8.3 mg/g for Bidens pilosa. The present study showed that these vegetables are valuable sources of phenolic compounds as compared to some exotic species.

Influence of bracken fern (Pteridium caudatum L. Maxon) pre-treatment on extraction yield of illudane glycosides and pterosins

INTRODUCTION

Bracken (Pteridium spp) illudane glycosidess are labile biologically active terpenoids that undergo decomposition in mild alkali or acid, heat and enzymatic reactions. Hypothetically, quantitation of these weakly chromophoric carcinogens may be challenged by plant sample preparation procedures that may alter the yield of isolates.

OBJECTIVE

To study the influence of common plant sample pre-treatments on the recovery of Pteridium caudatum illudane glycoside carcinogens, ptaquiloside (1a), caudatoside (1c) and ptaquiloside Z (1d), and associated pterosins A, B and Z (2a, b, c) using HPLC-DAD.

METHOD

Bracken fronds were divided in equal left/right sections. One section was subjected to high vacuum desiccation (VD) and the other to freeze-drying (FD), air drying at room temperature (AD) for 7 days, air drying at 70 °C for 72 h (HD), or no treatment (fresh frond, FF). Quantitation was achieved by brief hot-water extraction, base-acid transformation of 1a, 1c and 1d to 2a, b, c and HPLC-DAD analysis against standards.

RESULTS

Substantial differences in extraction yields were found for all illudane glycosides in the order FF > FD ≈ VD > AD > HD. Illudane instability to HD was 1c > 1d > 1a. Significant losses also were recorded in yields of Pterosins A, B and Z.

CONCLUSION

Glycoside extraction suffers from substantial yield loss of all illudane glycosides and indigenous pterosins in all sample pre-treatments studied relative to fresh frond material.

An integrated approach to demonstrating the ANR pathway of proanthocyanidin biosynthesis in plants

Proanthocyanidins (PAs) are oligomers or polymers of plant flavan-3-ols and are important to plant adaptation in extreme environmental conditions. The characterization of anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) has demonstrated the different biogenesis of four stereo-configurations of flavan-3-ols. It is important to understand whether ANR and the ANR pathway widely occur in the plant kingdom. Here, we report an integrated approach to demonstrate the ANR pathway in plants. This includes different methods to extract native ANR from different tissues of eight angiosperm plants (Lotus corniculatus, Desmodium uncinatum, Medicago sativa, Hordeum vulgare, Vitis vinifera, Vitis bellula, Parthenocissus heterophylla, and Cerasus serrulata) and one fern plant (Dryopteris pycnopteroides), a general enzymatic analysis approach to demonstrate the ANR activity, high-performance liquid chromatography-based fingerprinting to demonstrate (-)-epicatechin and other flavan-3-ol molecules, and phytochemical analysis of PAs. Results demonstrate that in addition to leaves of M. sativa, tissues of other eight plants contain an active ANR pathway. Particularly, the leaves, flowers and pods of D. uncinatum, which is a model plant to study LAR and the LAR pathways, are demonstrated to express an active ANR pathway. This finding suggests that the ANR pathway involves PA biosynthesis in D. uncinatum. In addition, a sequence BLAST analysis reveals that ANR homologs have been sequenced in plants from both gymnosperms and angiosperms. These data show that the ANR pathway to PA biosynthesis occurs in both seed and seedless vascular plants.

Habitat influence on antioxidant activity and tannin concentrations of Spondias tuberosa

CONTEXT

Different habitat conditions can be responsible for the production of secondary metabolites and for the antioxidant properties of plant products.

OBJECTIVE

Thus, the aim of this study was to evaluate whether the antioxidant activity and tannin concentrations in the stem bark of Spondias tuberosa Arruda (Anacardiaceae) varied with collection site.

MATERIAL AND METHODS

The bark was collected from 25 individual trees, distributed in five different landscape units, as follows: agroforestry gardens, areas of pastures, maize cultivation areas, mountain areas and mountain bases, with the former 3 being considered as anthropogenic habitats, and the latter 2 considered as habitats with native coverage. The study was conducted in the rural area of the city of Altinho, Pernambuco State (Northeast Brazil). The DPPH (1,1-diphenyl-2-picrylhydrazyl) method was used to measure the antioxidant activity and tannin concentrations were evaluated by using the radial diffusion method.

RESULTS

The results demonstrated that there were no significant differences among the tannin concentrations of the individuals from the native (6.27% ± 1.75) or anthropogenic areas (4.63% ± 2.55), (H = 2.24; p > 0.05). In contrast, there were significant differences (H = 5.1723; p < 0.05) among the CE₅₀ means of the antioxidant activities of the individuals from the native (32.10 µg/ml ± 5.27) and anthropogenic areas (27.07 µg/ml ± 2.29). However, correlations between the tannin concentrations and antioxidant activity of the extracts were not observed in the native (r = 0.39; p > 0.05) or in the anthropogenic areas (r = 0.38; p > 0.05).

DISCUSSION AND CONCLUSION

Because the variation of the antioxidant capacity of S. tuberosa bark was not accompanied by a variation in the tannin concentration, this property may be related to the presence of other metabolite(s).

Variations in antioxidant properties of strawberries grown in Brazilian savannah and harvested in different seasons

BACKGROUND

Strawberries are nutritive fruits and a source of antioxidants. We evaluated antioxidant properties of 'Camino Real' strawberries grown in the Brazilian savannah, harvested in different seasons. Analytical and meteorological data were analyzed by partial least squares regression.

RESULTS

Fruits from May showed the lowest contents of total phenolics (1789.78 mg kg⁻¹ fresh weight (FW)), catechin (21.37 mg kg⁻¹ FW), quercetins (4.89 mg kg⁻¹ FW) and total ellagic acid (208.68 mg kg⁻¹ FW) and the lowest antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) (11.39 mg Butylated hydroxytoluene (BHT) eq. g⁻¹ FW) and ferric reducing antioxidant power (FRAP) (22.01 mg ferrous sulfate eq. g⁻¹ FW) assays. Strawberries harvested in July presented the lowest concentrations of total (190.61 mg kg⁻¹ FW) and individual anthocyanins (73.88 mg kg⁻¹ FW and 5.96 mg kg⁻¹ FW for pelargonidin-3-glucoside and cyanidin-3-glucoside, respectively), but the highest contents of vitamin C (685.47 mg kg⁻¹ FW), DPPH (18.87 mg BHT eq. g⁻¹ FW) and FRAP (39.30 mg ferrous sulfate eq. g⁻¹ FW). The highest contents of free ellagic acid (26.11 mg kg⁻¹ FW), pelargonidin-3-glucoside (291.82 mg kg⁻¹ FW) and cyanidin-3-glucoside (11.84 mg kg⁻¹ FW) were found in strawberries from September. Rain in the previous 30 days to harvest influenced negatively many phenolics and antioxidant activity of strawberries harvested in May. In July, longer photoperiod and lower temperature at 30 days previous to harvest probably led to higher antioxidant activity and vitamin C. Increased photoperiod and temperature at the final stage of maturation seem to raise pigments and free ellagic acid in strawberries.

CONCLUSION

It was possible to observe significant relationships among meteorological and antioxidant variables for strawberries grown in the Brazilian savannah.

Influence of cultivation conditions, season of collection and extraction method on the content of antileishmanial flavonoids from Kalanchoe pinnata

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves from Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) are popularly used for healing wounds. Its antileishmanial properties are established in experimental animals, and its active flavonoid components have been identified.

AIM OF THE STUDY

In this study, we attempted to standardize the extract from K. pinnata leaves by evaluating the influence of season of harvest, sunlight exposure and method of extraction on antileishmanial flavonoids content.

MATERIALS AND METHODS

HPLC-DAD-MS was used to identify and quantify the active antileishmanial flavonoids in different extracts. ANOVA test for analyses of variance followed by the Tukey test of multiple comparisons were used in the statistical analysis. The antileishmanial potential was assessed by the activation of nitric oxide production by murine macrophage using the Griess method.

RESULTS

We demonstrated that active flavonoids were significantly more abundant when the leaves were collected in the summer, and that aqueous extraction at 50°C allowed the highest flavonoid extraction. The benefit of sunlight exposure was confirmed in plants cultivated under direct sunlight when compared with those that grown under shade. Under sunny conditions the yield of the most active antileishmanial favonoid quercitrin was increased by 7-fold. All aqueous extracts tested were capable to enhance the macrophage nitric oxide production. However, hot aqueous extract from leaves collected in summer exhibited the higher activity, in agreement with HPLC-DAD-MS analysis tendency. In addition, with the aim of reducing the individual chemical variations of the plant constituents and optimizing the production of the active extract, it was obtained in vitro monoclonal KP specimens that were easily adapted to field conditions and were able to produce antileishmanial flavonoids.

CONCLUSION

Our study reports the better conditions of cultivation, harvest and extraction protocol for obtaining a K. pinnata extract exhibiting the highest antileishmanial activity. Additionally, we propose the flavonoids quercetin 3-O-α-L-arabinopyranosyl (1→2)-α-L-rhamnopyranoside and quercitrin, as satisfactory chemical markers for standardization purposes.

The dynamics of phenolic concentration in some pasture species and implications for animal husbandry

BACKGROUND

Although secondary metabolites have often been studied considering their primary role as plant-defensive and their effect on consumers detrimental, their effects are usually dose-dependent, so it is important to consider their content at all phenological phases and in different plant organs. In this study the content of total phenolics (TotP), non-tannic phenolics (NTP) and proanthocyanidins (PA) was determined in natural populations of pasture species at defined phenological phases and in different plant organs and also in pathogen-infected plants.

RESULTS

Variation in TotP, NTP and PA content was observed in all species, phenological phases and plant organs. Leaf blades were the organs with the highest content in all species. The content of all examined compounds increased in infected leaves, reaching the maximum when 20% of plant tissues were attacked and decreasing at higher infection levels.

CONCLUSION

Delphinidin was found as an appropriate standard related to the PA structure of each plant species. PA concentrations were always in the range considered beneficial for animals, not exceeding 60 g delphinidin equivalent kg(-1) dry matter. The Folin-Ciocalteu and butanol/HCl/Fe(3+) assays remain the most practical methods for screening large numbers of different plant species for TotP and PA.

Evaluation of antihyperglycemia and antihypertension potential of native Peruvian fruits using in vitro models

Local food diversity and traditional crops are essential for cost-effective management of the global epidemic of type 2 diabetes and associated complications of hypertension. Water and 12% ethanol extracts of native Peruvian fruits such as Lucuma (Pouteria lucuma), Pacae (Inga feuille), Papayita arequipeña (Carica pubescens), Capuli (Prunus capuli), Aguaymanto (Physalis peruviana), and Algarrobo (Prosopis pallida) were evaluated for total phenolics, antioxidant activity based on 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay, and functionality such as in vitro inhibition of alpha-amylase, alpha-glucosidase, and angiotensin I-converting enzyme (ACE) relevant for potential management of hyperglycemia and hypertension linked to type 2 diabetes. The total phenolic content ranged from 3.2 (Aguaymanto) to 11.4 (Lucuma fruit) mg/g of sample dry weight. A significant positive correlation was found between total phenolic content and antioxidant activity for the ethanolic extracts. No phenolic compound was detected in Lucuma (fruit and powder) and Pacae. Aqueous extracts from Lucuma and Algarrobo had the highest alpha-glucosidase inhibitory activities. Papayita arequipeña and Algarrobo had significant ACE inhibitory activities reflecting antihypertensive potential. These in vitro results point to the excellent potential of Peruvian fruits for food-based strategies for complementing effective antidiabetes and antihypertension solutions based on further animal and clinical studies.