Total flavonoid concentrations of bryophytes from Tianmu Mountain, Zhejiang Province (China): Phylogeny and ecological factors

Comparison of Flavonoid Content, Antioxidant Potential, Acetylcholinesterase Inhibition Activity and Volatile Components Based on HS-SPME-GC-MS of Different Parts from Matteuccia struthiopteris (L.) Todaro

Matteuccia struthiopteris is one of the most globally consumed edible ferns and widely used in folk medicine. Reports mainly focus on young fronds and the rhizome which are common edible medicinal parts. However, there are few detailed reports on other parts. Therefore, the volatile components of different parts based on HS-SPME-GC-MS were identified, and total flavonoid contents, antioxidant activities and acetylcholinesterase inhibitory activities were compared in order to reveal the difference of volatile components and potential medicinal value of different parts. The results showed that total flavonoid contents, antioxidant activities and volatile components of different parts were obviously different. The crozier exhibited the strongest antioxidant activities, but only underground parts exhibited a dose-dependent inhibition potential against AChE. Common volatile compounds were furfural and 2-furancarboxaldehyde, 5-methyl-. In addition, it was found that some volatile components from adventitious root, trophophyll, sporophyll and petiole were important ingredients in food, cosmetics, industrial manufacturing and pharmaceutical applications.

Influence of phytocenosis on the medical potential of moss extracts: the Pleurozium schreberi (Willd. ex Brid.) Mitt. case

The question was asked "whether plant phytocenosis has an impact on the medical potential of the extracts from Pleurozium schreberi". Moss samples were collected from four different phytocoenoses: mixed forest (oak-pine forest), a forest tract in pine forest, 5-15-year-old pine forest and 50-year-old pine forest. Chemical composition of the extracts, antioxidative capacity (FRAP and ABTS·+ assays), as well as biological activities including cytotoxicity for the mouse fibroblasts L929 line (MTT reduction assay), biostatic/biocidal effect against selected bacteria and fungi (broth microdilution method followed by culture on solid media), and regenerative properties on human fibroblasts HFF-1 line (scratch assay) were tested. The conducted research clearly proves that phytocenosis determines the quality of moss extracts. The analyses showed that in every examined aspect the IV-7 extract (obtained from a specimen collected in a Pinus sylvestris L. forest, monoculture up to 15 years old) exhibited the highest values and the strongest activity. Other extracts of the same species but growing in other phytocenoses-in a mixed forest (IV-5), a forest tract in a Pinus sylvestris monoculture forest (IV-6) and in a P. sylvestris forest of pine monoculture about 50 years old (IV-8) showed much weaker activity and lower values of the above-mentioned parameters. At the same time, none of the tested extracts exerted a pro-regenerative effect. The P. schreberi extracts were characterized by a varied total content of phenolic compounds in the range from 0.63 ± 0.02 to 14.01 ± 0.25 mg/g of plant material. UPLC/MS analysis showed a varied phenolic profile of the extracts, with caffeoylquinic acid and quercetin triglucoside predominating in all of them.

Impact of in vitro phytohormone treatments on the metabolome of the leafy liverwort Radula complanata (L.) Dumort

INTRODUCTION

Liverworts are a group of non-vascular plants that possess unique metabolism not found in other plants. Many liverwort metabolites have interesting structural and biochemical characteristics, however the fluctuations of these metabolites in response to stressors is largely unknown.

OBJECTIVES

To investigate the metabolic stress-response of the leafy liverwort Radula complanata.

METHODS

Five phytohormones were applied exogenously to in vitro cultured R. complanata and an untargeted metabolomic analysis was conducted. Compound classification and identification was performed with CANOPUS and SIRIUS while statistical analyses including PCA, ANOVA, and variable selection using BORUTA were conducted to identify metabolic shifts.

RESULTS

It was found that R. complanata was predominantly composed of carboxylic acids and derivatives, followed by benzene and substituted derivatives, fatty acyls, organooxygen compounds, prenol lipids, and flavonoids. The PCA revealed that samples grouped based on the type of hormone applied, and the variable selection using BORUTA (Random Forest) revealed 71 identified and/or classified features that fluctuated with phytohormone application. The stress-response treatments largely reduced the production of the selected primary metabolites while the growth treatments resulted in increased production of these compounds. 4-(3-Methyl-2-butenyl)-5-phenethylbenzene-1,3-diol was identified as a biomarker for the growth treatments while GDP-hexose was identified as a biomarker for the stress-response treatments.

CONCLUSION

Exogenous phytohormone application caused clear metabolic shifts in Radula complanata that deviate from the responses of vascular plants. Further identification of the selected metabolite features can reveal metabolic biomarkers unique to liverworts and provide more insight into liverwort stress responses.

Host Tree and Geography Induce Metabolic Shifts in the Epiphytic Liverwort Radula complanata

Bryophytes are prolific producers of unique, specialized metabolites that are not found in other plants. As many of these unique natural products are potentially interesting, for example, pharmacological use, variations in the production regarding ecological or environmental conditions have not often been investigated. Here, we investigate metabolic shifts in the epiphytic Radula complanata L. (Dumort) with regard to different environmental conditions and the type of phorophyte (host tree). Plant material was harvested from three different locations in Sweden, Germany, and Canada and subjected to untargeted liquid chromatography high-resolution mass-spectrometry (UPLC/ESI-QTOF-MS) and data-dependent acquisition (DDA-MS). Using multivariate statistics, variable selection methods, in silico compound identification, and compound classification, a large amount of variation (39%) in the metabolite profiles was attributed to the type of host tree and 25% to differences in environmental conditions. We identified 55 compounds to vary significantly depending on the host tree (36 on the family level) and 23 compounds to characterize R. complanata in different environments. Taken together, we found metabolic shifts mainly in primary metabolites that were associated with the drought response to different humidity levels. The metabolic shifts were highly specific to the host tree, including mostly specialized metabolites suggesting high levels of ecological interaction. As R. complanata is a widely distributed generalist species, we found it to flexibly adapt its metabolome according to different conditions. We found metabolic composition to also mirror the constitution of the habitat, which makes it interesting for conservation measures.

Ruthana date extract inhibited proliferation of human hepatocellular carcinoma (HepG2) cells by modulation of BAX gene

Cancer response to chemotherapeutic agents and its side effects remain a challenge for the development of new anticancer compounds. Dates are consumed worldwide due to their high nutritional value. We investigated the cytotoxicity and expression of the proapoptotic BAX gene in human hepatocellular carcinoma (HepG2) cells treated with Ruthana date ethanolic extract (RDE). The RDE ingredients analyzed by GC/MS and HepG2 cells were treated with different concentrations of RDE for 24, 48, and 72 h. Cytotoxicity, cell viability, DNA fragmentation, and BAX expression were determined. The GC/MS analysis of RDE showed its high content of quercetin, myricetin kaempferol, thymine, and catechol as the most active ingredients. HepG2 treated with RDE showed a significant change in morphological characteristics related to cell death. The antiproliferative activity determined by WST-1 demonstrated that RDE significantly reduced cell viability. Cells treated with RDE (10-60 mg) showed gradual DNA fragmentation in a dose-dependent manner. Gene expression analysis showed upregulation of BAX at 30 mg/ml of RDE (p < 0.001). However, it showed downregulation at (40-60 mg/ml) as compared to control. Our findings indicated that RDE exert cytotoxicity against HepG2 cells due to its high content of flavonoids. This effect through DNA fragmentation and activation of the proapoptotic BAX gene.

Comparative metabolomic and transcriptomic analyses revealed the differential accumulation of secondary metabolites during the ripening process of acerola cherry (Malpighia emarginata) fruit

BACKGROUND

Acerola cherry is a famous functional fruit containing plentiful antioxidants and other nutrients. However, studies on the variations among nutrients during the ripening process of acerola fruit are scare.

RESULTS

Comparative metabolomic and transcriptomic analyses were performed and identified 31 331 unigenes and 1896 annotated metabolite features in acerola cherry fruit. K Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that several antioxidant and nutrient-related metabolic pathways, such as the flavonoids, vitamins, carotenoids, amino acids, and fatty acids metabolic pathways, were significantly changed during the ripening process. The metabolites related to the vitamin, carotenoid, and fatty acid metabolic pathways were downregulated during the ripening process. Several flavonoid biosynthesis-related genes (including dihydroflavonol 4-reductase, chalcone synthase, flavanone 3-hydroxylase, and anthocyanidin synthase), were significantly upregulated, suggesting their essential functions in the accumulation of flavonoids in mature fruit.

CONCLUSION

Most of the vitamin and carotenoid metabolism-related metabolites significantly accumulated in immature fruit, suggesting that immature acerola fruit is a good material for the extraction of vitamins and carotenoids. For macronutrients, most of the amino acids accumulated in mature fruit and most of the fatty acids greatly accumulated in immature fruit. Our data revealed the differential accumulation of antioxidants and nutrients during the ripening process of acerola cherry fruit. © 2021 Society of Chemical Industry.

Metabarcoding reveals massive species diversity of Diptera in a subtropical ecosystem

Diptera is often considered to be the richest insect group due to its great species diversity and broad ecological versatility. However, data on dipteran diversity from subtropical ecosystems have hitherto been scarce, due to the lack of studies conducted at an appropriate large scale. We investigated the diversity and composition of Diptera communities on Tianmu Mountain, Zhejiang, China, using DNA metabarcoding technology, and evaluated their dynamic responses to the effects of slope aspect, season, and altitudinal zone. A total of 5,092 operational taxonomic units (OTUs) were discovered and tentatively assigned to 72 dipteran families, including 2 family records new for China and 30 family records new for the locality. Cecidomyiidae, Sciaridae, and Phoridae were the predominant families, representing 53.6% of total OTUs, while 52 families include >95% unidentified and presumed undescribed species. We found that the community structure of Diptera was significantly affected by aspect, seasonality (month) and elevation, with richer diversity harbored in north-facing than south-facing slopes, and seasonality a more profound driver of community structure and diversity than elevation. Overall, massive species diversity of Diptera communities was discovered in this subtropical ecosystem of east China. The huge diversity of potentially undescribed species only revealed by metabarcoding now requires more detailed taxonomic study, as a step toward an evolutionary integration that accumulates information on species' geographic ranges, ecological traits, functional roles, and species interactions, and thus places the local communities in the context of the growing knowledge base of global biodiversity and its response to environmental change.

Implications of ionizing radiation on pollen performance in comparison with diverse models of polar cell growth

Research concerning the effects of ionizing radiation (IR) on plant systems is essential for numerous aspects of human society, as for instance, in terms of agriculture and plant breeding, but additionally for elucidating consequences of radioactive contamination of the ecosphere. This comprehensive survey analyses effects of x- and γ-irradiation on male gametophytes comprising primarily in vitro but also in vivo data of diverse plant species. The IR-dose range for pollen performance was compiled and 50% inhibition doses (ID₅₀ ) for germination and tube growth were comparatively related to physiological characteristics of the microgametophyte. Factors influencing IR-susceptibility of mature pollen and polarized tube growth were evaluated, such as dose-rate, environmental conditions, or species-related variations. In addition, all available reports suggesting bio-positive IR-effects particularly on pollen performance were examined. Most importantly, for the first time influences of IR specifically on diverse phylogenetic models of polar cell growth were comparatively analysed, and thus demonstrated that the gametophytic system of pollen is extremely resistant to IR, more than plant sporophytes and especially much more than comparable animal cells. Beyond that, this study develops hypotheses regarding a molecular basis for the extreme IR-resistance of the plant microgametophyte and highlights its unique rank among organismal systems.

Flavonoids and antioxidant activity of rare and endangered fern: Isoetes sinensis

Isoetes sinensis Palmer is a critically endangered, first-class protected plant in China. Until now, researchers have primarily focused on the ultrastructure, phylogeny, and transcriptomes of the plant. However, flavonoid profiles and bioactivity of I. sinensis have not been extensively investigated. To develop the endangered I. sinensis for edible and medicinal purposes, flavonoid content, chemical constitution, and antioxidant activities were investigated in this study. Results revealed the following. 1) The total flavonoid content was determined as 10.74 ± 0.25 mg/g., 2) Antioxidant activities were stronger than most ferns, especially ABTS free radical scavenging activities. 3) Four flavones, containing apigenin, apigenin-7-glucuronide, acacetin-7-O-glcopyranoside, and homoplantageninisoetin; four flavonols, namely, isoetin, kaempferol-3-O-glucoside, quercetin-3-O-[6"-O-(3-hydroxy-3-methylglutaryl)-β-D-glucopyranoside], and limocitrin-Neo; one prodelphinidin (procyanidins;) and one nothofagin (dihydrochalcone) were tentatively identified in the mass spectrometry-DAD (254nm) chromatograms. This study was the first to report on flavonoid content and antioxidant activities of I. sinensis. Stronger antioxidant activity and flavonoid content suggests that the endangered I. sinensis is an important and potentially edible and medicinal plant.

Effects of different pretreatments on flavonoids and antioxidant activity of Dryopteris erythrosora leave

Flavonoids are secondary metabolites of plants that often have medical applications. The influences of different sample drying pretreatments on flavonoids and antioxidant activity of ferns have not studies. Dryopteris erythrosora leaves used to analyze flavonoid alterations resulting from drying pretreatments. The total flavonoid content of D. erythrosora leaves exposed to different pretreatments was significantly different. The total flavonoid content of samples initially air-dried in shade and then oven-dried at 75°C were the highest (7.6%), while samples initially dried at 75°C had the lowest content (2.17%). Antioxidant activities of D. erythrosora leaves with different pretreatments varied. Group B first air-dried in the shade and then oven-dried at 75°C and group C first air-dried in the sun and then oven-dried at 75°C, both showed relatively stronger antioxidant activity. The best pretreatment for preserving the flavonoids was to first dry the plant material in the shade and then complete the drying process in an oven at 75°C. It was tentatively identified 22 flavonoids among the four different pretreatments by HPLC-ESI-TOF-MS.

Correction: Total flavonoid concentrations of bryophytes from Tianmu Mountain, Zhejiang Province (China): Phylogeny and ecological factors

[This corrects the article DOI: 10.1371/journal.pone.0179837.].