Environmental factors affecting the concentration of phenolic compounds in Myrcia tomentosa leaves

Effects of Annual Growth Conditions on Phenolic Compounds and Antioxidant Activity in the Roots of Eryngium montanum

Medicinal plants grown in natural settings are exposed to different adverse environmental conditions that determine their growth and development as well as the composition and concentration of secondary metabolites in their organs. The objective of this study was to evaluate the effects of environmental conditions associated with localities and annual growth cycles on the contents of phenolic compounds and flavonoids, antioxidant activity and potentially bioactive phenolic acids in the roots of Eryngium montanum, a medicinal species from temperate Mexico. The samples for composition analysis were collected using a bifactorial design: Factor A consisted of the localities (Morelos and La Unión de San Martin Huamelulpam, Mexico) and Factor B was represented by the annual growth cycle (2020 and 2021). In each sample, the contents of polyphenols and equivalent flavonoids of quercetin and catechin and antioxidant activity were evaluated using spectrophotometry. Subsequently, chlorogenic, caffeic and rosmarinic acids were identified and quantified using high-performance liquid chromatography with diode-array detection (HPLC-DAD). The annual growth conditions and, to a lesser extent, the locality of origin of the samples significantly influenced the contents of phenolic compounds and antioxidant activity. The environmental conditions that occurred in 2021 favored an increase in the contents of phenolic compounds compared to those in 2020, and the same pattern was observed for chlorogenic acid; however, for caffeic and rosmarinic acids, the opposite pattern was observed. The content of phenolic acids in the roots of E. montanum follows different and independent patterns between cycles based on the interaction between the locality of origin and annual growth cycle. This study quantifies the magnitude of the total environmental effect on the phenolic compound concentrations in E. montanum roots, which was measured via sampling during two annual growth cycles, where the sampling locations factor had little influence. The bioactive compounds identified in E. montanum roots have the potential for use as alternative medicines, as mentioned by different families from Oaxaca, Mexico.

Effects of invasive Rosa rugosa on Baltic coastal dune communities depend on dune age

Rosa rugosa Thunb. (Japanese Rose) is one of the most invasive species in Europe. It spreads spontaneously in coastal areas of western, central and northern Europe, posing a threat to dune habitats, including those indicated in the EU Habitats Directive as particularly valuable. R. rugosa has already been reported to displace native plants and alter soil properties. However, little is known about how these effects are mediated by the habitat context or the invader condition (health, ontogenetic stage). This study addressed that gap by examining vegetation and soil in 22 R. rugosa-invaded sites, half of which were in yellow dunes and the other half in grey dunes, i.e. two habitats representing the earlier and later stages of dune succession. The study was conducted on the Hel Peninsula (Poland’s Baltic coast). R. rugosa had a significant impact on dune vegetation, but the impact was strongly dependent on the habitat type. In the yellow dune sites, R. rugosa outcompeted most resident plant species, which translated into a strong decline in their total cover and richness. The invasion was almost not accompanied by changes in soil properties, suggesting that it affected the resident vegetation directly (through space takeover and shading). In the grey dunes, R. rugosa caused a shift in species composition, from that characteristic of open communities to that typical of forests. In this habitat, a significant increase in the soil organic layer thickness under R. rugosa was also observed, which means that both direct and indirect effects of the invasion on the vegetation should be assumed. Finally, a negative relationship was found between the total chlorophyll content in R. rugosa leaves and the parameters of resident plant communities, showing that the invasion effects can vary not only across habitats, but also with the condition of the invader. The results may have practical implications for managing R. rugosa invasions in coastal sand dune systems. Since R. rugosa accelerates grey dune succession, protecting this habitat may be more urgent and, at the same time, more complicated than protecting dunes at the earlier stages of development.

Biochemical Composition and Biological Activities of Various Population of Brassica tournefortii Growing Wild in Tunisia

Brassica tournefortii Gouan, commonly known (Aslooz) in Tunisia, is an annual plant, native to the North Africa and Middle East. Brassica species are used as food, their young leaves can be cooked, providing nutrients and health-giving phytochemicals such as phenolic compounds, polyphenols and carotenoids. Phytochemical composition and bioactivity of Brassica tournefortii leaf extracts, collected from four different bioclimatic zones in Tunisia, are investigated in the present study. Results showed that location and climatic variations can alter the phytochemical composition of B. tournefortii. Interestingly, HPLC analysis enabled identifying lutein and beta-carotene at high concentrations, especially in extracts of B. tournefortii collected from Gabes (B2) (344 µg/g of lutein) and B. tournefortii collected from Zarzis (B3) (1364 µg/g of beta-carotene). In particular, the antioxidant activity measured by DPPH assay showed that the extract of the plants collected from the growing region of Zarzis exhibits the highest antioxidant activities (0.99 mg/mL). All the Brassica tournefortii extracts showed a relevant antiproliferative activity, especially toward the Caco-2 cell line. These preliminary data resulted in being useful to correlate growth environmental conditions with different accumulation of metabolites in Brassica species still being poorly studied.

Patterns of Plumericin Concentration in Leaves of Himatanthus tarapotensis (Apocynaceae) and Its Interactions with Herbivory in the Peruvian Amazon

We explored the concentration patterns of the bioactive metabolite plumericin produced by Himatanthus tarapotensis (Apocynaceae) under different edaphic conditions and variations in rainfall intensity, as well as its potential role in the chemical defense against insect herbivores. Values of plumericin concentration from leaves were obtained by High-Performance Liquid Chromatography, and evaluated as a function of differences in soil types, variation of precipitation, and variation of the abundance of insect herbivores, using first a Repeated Measures Correlation (rmcorr) and then a Generalized Linear Mixed Model (GLMM) analysis. Plumericin concentration is highly variable among plants, but with a significantly higher concentration in plants growing on clay soil compared to that of the white-sand soil habitat (p < 0.001). Plumericin concentration is not affected by precipitation. The caterpillar of Isognathus leachii (Lepidoptera: Sphingidae) is the most conspicuous herbivore of H. tarapotensis, and its presence is continuous but not related to plumericin concentration, probably because of its capacity to elude the chemical defense of this plant. Nevertheless, our multivariate model revealed that plumericin concentration is related to the abundance of Hymenoptera (Formicidae), and this relationship is significantly influenced by the soil parameters of carbon percentage, clay percentage, and phosphorous percentage (p < 0.001). Plumericin is a mediating agent in the interaction between H. tarapotensis and its natural environment. Variation in plumericin concentration would be induced by the abundance of Hymenoptera (Formicidae), probably as a chemical response against these insects, and by differences in soil nutrient availability.

Ethnobotanical and Biochemical Study of Berberis lycium Royle Collected from Different Areas of Azad Jammu and Kashmir

Berberis lycium Royle has a long history of medicinal uses to treat different diseases. It naturally grows on the mountains of Indian subcontinent. Its ethnobotanical and biochemical study from the state of Azad Jammu and Kashmir (AJ&K) was not previously explored. So, the objective of the current study was to explore the ethnobotanical and biochemical properties of the B. lycium Royle population of AJ&K. For this purpose, samples of B. lycium Royle were randomly collected from five districts of Azad Jammu and Kashmir, including thirty-five locations. Demographic features of informants such as plant part used, methods of preparation, modes of administration, conservation status, and ethnomedicinal uses were documented. It was used for treating different diseases such as diabetes, arthritis, joint pain, and stomach ulcer. This plant is very famous for providing medicinal roots, leaves, and fruits which are extensively used in many parts of the world. The biochemical analysis was conducted for total phenolic contents (TPC), chlorophyll contents, and antioxidant activity. The highest level of TPC found was 88.66 ± 1.07 µg/g of gallic acid equivalent phenolic (GAE) from leaves collected from Patikka (Chanjhal), Muzaffarabad District, AJ&K. The highest total chlorophyll contents (3.75 ± 0.53 µg/ml) were found in samples collected from Sathrian, Neelum District. The highest antioxidant activity with lowest IC50 value (33.26 µg/ml) was obtained from the root of sample collected from Bakreyali, Muzaffarabad District, as compared with other districts. The concentration of berberine was found to be 4.76 percent in the root bark of B. lycium Royle, estimated by high-performance liquid chromatography (HPLC). In syrup composition, 0.95 mg/5 ml of berberine was used. Hence, it is concluded that amongst the five districts, the plant parts (stem, fruits, and root) collected from Muzaffarabad District, AJ&K, showed the highest medicinal potential due to its unique climatic conditions.

Morphological and Chemical Diversity and Antioxidant Capacity of the Service Tree (Sorbus domestica L.) Fruits from Two Eco-Geographical Regions

Service tree, Sorbus domestica L., is a rare and neglected wild fruit tree species of southern and central Europe. Being distributed in different eco-geographical regions, with fragmented and low-density populations, S. domestica represents an interesting model case for investigating patterns of within- and between-population diversity at geographical and environmental scales. This study aimed to analyze the proximate composition, antioxidant activity, and morphometric fruit characteristics. We examined the diversity and population divergences of 49 S. domestica individuals originating from seven populations across continental and Mediterranean eco-geographical regions. In addition, tests of isolation by distance and environment were performed to detect the magnitude of divergence explained by geographic and environmental variables. Significant differences between the studied populations were found in almost all of the studied morphometric and chemical fruit characteristics. The studied service tree populations were characterized by high phenotypic variation despite the low number of trees per population. Model-based population structure analysis using morphometric and chemical fruit characteristics revealed three groups of service tree populations. We concluded that non-effective pollen and seed dispersal along with genetic drift and specific environmental factors resulted in a distinct phenotype with a specific chemical composition in the isolated island population. In addition, a pattern of isolation by the environment was revealed. We infer that morphological and chemical differences between the studied populations in the true service tree from different eco-geographical regions were mediated by adaptation to the specific environmental conditions.

Metabolomics of Myrcia bella Populations in Brazilian Savanna Reveals Strong Influence of Environmental Factors on Its Specialized Metabolism

Environmental conditions influence specialized plant metabolism. However, many studies aiming to understand these modulations have been conducted with model plants and/or under controlled conditions, thus not reflecting the complex interaction between plants and environment. To fully grasp these interactions, we investigated the specialized metabolism and genetic diversity of a native plant in its natural environment. We chose Myrcia bella due to its medicinal interest and occurrence in Brazilian savanna regions with diverse climate and soil conditions. An LC-HRMS-based metabolomics approach was applied to analyze 271 samples harvested across seven regions during the dry and rainy season. Genetic diversity was assessed in a subset of 40 samples using amplified fragment length polymorphism. Meteorological factors including rainfall, temperature, radiation, humidity, and soil nutrient and mineral composition were recorded in each region and correlated with chemical variation through multivariate analysis (MVDA). Marker compounds were selected using a statistically informed molecular network and annotated by dereplication against an in silico database of natural products. The integrated results evidenced different chemotypes, with variation in flavonoid and tannin content mainly linked to soil conditions. Different levels of genetic diversity and distance of populations were found to be correlated with the identified chemotypes. These observations and the proposed analytical workflow contribute to the global understanding of the impact of abiotic factors and genotype on the accumulation of given metabolites and, therefore, could be valuable to guide further medicinal exploration of native species.

Constituents and Pharmacological Activities of Myrcia (Myrtaceae): A Review of an Aromatic and Medicinal Group of Plants

Myrcia is one of the largest genera of the economically important family Myrtaceae. Some of the species are used in folk medicine, such as a group known as “pedra-hume-caá” or “pedra-ume-caá” or “insulina vegetal” (insulin plant) that it is used for the treatment of diabetes. The species are an important source of essential oils, and most of the chemical studies on Myrcia describe the chemical composition of the essential oils, in which mono- and sesquiterpenes are predominant. The non-volatile compounds isolated from Myrcia are usually flavonoids, tannins, acetophenone derivatives and triterpenes. Anti-inflammatory, antinociceptive, antioxidant, antimicrobial activities have been described to Myrcia essential oils, while hypoglycemic, anti-hemorrhagic and antioxidant activities were attributed to the extracts. Flavonoid glucosides and acetophenone derivatives showed aldose reductase and α-glucosidase inhibition, and could explain the traditional use of Myrcia species to treat diabetes. Antimicrobial and anti-inflammatory are some of the activities observed for other isolated compounds from Myrcia.

Seasonal Variations of Metabolome and Tyrosinase Inhibitory Activity of Lespedeza maximowiczii during Growth Periods

Lespedeza species are useful for pasture and energy crops as well as medical plants. We determined the metabolites discriminated from the each growth period (3, 4, 6, 8, 15, and 18 months) after germination in leaves and stems of Lespedeza maximowizii by a metabolomics technique. Specifically, levels of sugars and luteolin-dominated derivatives were significantly elevated in samples harvested in November. This may be related to the cold tolerance mechanism against the low temperatures of the winter season. The concentrations of secondary metabolites, isoflavones and flavanones, as well as tyrosinase inhibitory activity were the highest in the 6 month samples, which were harvested in September, during the fall season. The tyrosinase inhibitory activity in leaves was higher than that in stems irrespective of the growth period. This study suggests that mass spectrometry-based metabolite profiling could be used as a tool to examine quantitative or qualitative metabolite changes related to seasonal variations and to understand the correlation between activity and metabolites.

Antioxidant Activity and Phenolic Content of Bergenia crassifolia, B. x ornata and B. ciliata

This study focused on a phytochemical analysis of Bergenia crassifolia (L.) Fritsch., B. ciliata (Haw.) Sternb., and B. x ornata Stein. and evaluation of their free radical scavenging properties. Arbutin and total tannin contents of the leaves of the Bergenia species were determined during different seasons. The present study also aimed at analyzing, for the first time, environmental influence on concentrations of phenolic metabolites in Bergenia leaves. The highest total tannin content was found in the leaves of B. crassifolia (24.9 – 48.7 mg.g−1 DW) and B. x ornata (36.9 mg.g−1 DW). The highest amount of arbutin was in the leaves of B. x ornata (35.8 – 51.0 mg.g−1 DW) and B. crassifolia (24.6 – 41.7 mg.g−1 DW). Autumn was better than spring for the collection of Bergenia leaves for the highest amount of arbutin ( B. x ornata: 51.0 mg.g−1 DW). Free radical scavenging potential, in DPPH and ABTS assays, of the water leaf extracts revealed that extracts of B. crassifolia and B. x ornata are the most active radical scavengers. Antioxidant activity correlated well with the content of total tannin, especially in the ABTS assay, which suggests an important role for these compounds in antioxidant activity. It was shown that phenolic concentrations in Bergenia leaves are affected by seasonal factors. A significant correlation was found between arbutin and tannin contents and the average humidity.