Content of resveratrol and glycoside and its contribution to the antioxidative capacity of Polygonum cuspidatum (Itadori) harvested in Kochi

Comparison of Vegetable Waste Byproducts of Selected Cultivars of Foeniculum vulgare Mill. by an Integrated LC-(HR)MS and 1H-NMR-Based Metabolomics Approach

INTRODUCTION

The metabolome of plants is influenced by various factors, especially environmental, as the season in which they are grown. So, distinct varieties of the identical plant might show an increase or decrease in metabolites. The diversity of content of primary and secondary metabolites can also determine the variation in their biological properties. Due to the current occurrence of various fennel varieties, the crop can now be grown for the entire year.

OBJECTIVE

This work used an integrated approach of LC/MS and NMR analysis to characterize the metabolome of fennel waste of different varieties by multivariate statistical analysis.

METHODS

The extracts were investigated by NMR and LC/MS analysis to focus attention on the primary and secondary metabolites. Both LC-HRMS and NMR data were analyzed by principal component analysis (PCA).

RESULTS

The 1H-NMR analysis led to the identification of 15 primary metabolites, such as amino acids, carbohydrates, and organic acid derivatives. The secondary metabolites identified by LC/MS analysis mainly belong to the phenolic, lipid, and fatty acid compounds classes.

CONCLUSION

This integrated approach guarantees a precise and complete overview of the variations in the metabolic expression of the fennel varieties grown in different seasons.

Screening and Evaluation of Dermo-Cosmetic Activities of the Invasive Plant Species Polygonum cuspidatum

Polygonum cuspidatum (P. cuspidatum) is among the world's most problematic invasive plant species with negative ecological, socio-economic and security consequences. Management operations in areas invaded systematically generate a large quantity of plant waste, most often without outlets. Using this plant material could constitute a new alternative treatment for sustainable management. P. cuspidatum is well known to have numerous biological properties, containing notably stilbenes, quinones, flavonoids and phenolic acids. The present work proposes a reliable strategy using powerful techniques for the screening and the evaluation of the dermo-cosmetic potential of its aerial parts (AP) and root parts (RP). To the best of our knowledge, only antioxidant and anti-tyrosinase activities were previously evaluated on P. cuspidatum among the targets studied (superoxide dismutase, hyaluronidase, elastase, collagenase and tyrosinase). The results revealed strong antioxidant and anti-collagenase activities, moderate anti-hyaluronidase activity, while weak anti-elastase and anti-tyrosinase activities were observed for ethanolic extracts. Different standards selected and screened on the same targets made it possible to correlate the observed residual activities of produced extracts of P. cuspidatum from Savoie Mont Blanc and their chemical compositions. A structure-activity study was thus conducted on main molecular families, widely represented in the genus Polygonum.

Characterization of the chemical constituents and metabolic profile of Polygonum cuspidatum Sieb. et Zucc. in rat plasma, urine, and feces by ultra-high performance liquid chromatography coupled with Quadrupole-Exactive Orbitrap mass spectrometry

Polygonum cuspidatum Sieb. et Zucc. is a traditional and popular Chinese medicine with a wide spectrum of pharmacological effects such as anti-bacterial, anti-inflammatory, and anti-tumor activities together with other health effects like lowering lipids, preventing diabetes, and regulating the immune system. It is of great significance to explore the complex chemical constituents and metabolic process of Polygonum cuspidatum in vivo to further clarify the effective substances. However, studies on its metabolism in vivo were not comprehensive in previous literature. In this study, ultra-high performance liquid chromatography coupled with Quadrupole-Exactive Orbitrap mass spectrometry was used to comprehensively identify the chemical constituents in Polygonum cuspidatum and further analyze its metabolic profile in rats. Compared with reference substances, various databases, and literature retrieval, 62 compounds were inferred from the Polygonum cuspidatum extract. Furthermore, a total of 119 compounds, including 44 prototype compounds and 75 metabolites, were annotated in rat plasma, urine, and feces. The main metabolic pathways of Polygonum cuspidatum in rats included hydrogenation reduction, hydroxylation, dehydration, methylation, sulfation, and glucuronidation. This is the first systematic study on the chemical constituents of Polygonum cuspidatum and its metabolic profile in vivo, which contributes to finding its bioactive components and seeking its therapeutic targets.

Japanese Knotweed Rhizome Bark Extract Inhibits Live SARS-CoV-2 In Vitro

Coronavirus disease 2019 (COVID-19), a viral infectious respiratory disease, is caused by highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is responsible for the ongoing COVID-19 pandemic. Since very few drugs are known to be effective against SARS-CoV-2, there is a general need for new therapeutics, including plant-based drugs, for the prophylaxis and treatment of infections. In the current study, the activity of a 70% ethanolic(aq) extract of the rhizome bark of Japanese knotweed, an invasive alien plant species, was tested for the first time against the wild-type SARS-CoV-2 virus using a specific and robust virus neutralization test (VNT) on Vero-E6 cells, which best mimics the mechanism of real virus−host interaction. A statistically significant antiviral effect against SARS-CoV-2 (p-value < 0.05) was observed for the 50.8 µg mL−1 extract solution in cell medium. A suitable extract preparation was described to avoid loss of polyphenols throughout filtration of the extract, which was dissolved in cell medium containing fetal bovine serum (FBS). The significance of the differences between the sums of the test and control groups in the incidence of cytopathic effects (CPE) was determined using the one-way ANOVA test. A dose−response relationship was observed, with the cytotoxic effect occurring at higher concentrations of the extract (≥101.6 µg mL−1). The obtained results suggest possible use of this plant material for the production of various products (e.g., packaging, hygiene products, biodisinfectants, etc.) that would be useful against the spread of and for self-protection against COVID-19.

Antioxidant and Antimicrobial Biofoil Based on Chitosan and Japanese Knotweed (Fallopia japonica, Houtt.) Rhizome Bark Extract

A 70% ethanol_(aq) extract of the rhizome bark of the invasive alien plant species Japanese knotweed (JKRB) with potent (in the range of vitamin C) and stable antioxidant activity was incorporated in 1% w/v into a chitosan biofoil, which was then characterized on a lab-scale. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay confirmed the antioxidant activity of the JKRB biofoil upon contact with the food simulants A, B, C, and D1 (measured half-maximal inhibitory concentrations—IC₅₀) and supported the Folin–Ciocalteu assay result. The migration of the antioxidant marker, (−)-epicatechin, into all food simulants (A, B, C, D1, D2, and E) was quantified using liquid chromatography hyphenated to mass spectrometry (LC-MS). Calculations showed that 1 cm² of JKRB biofoil provided antioxidant activity to ~0.5 L of liquid food upon 1 h of contact. The JKRB biofoil demonstrated antimicrobial activity against Gram-positive bacteria. The incorporation of JKRB into the chitosan biofoil resulted in improved tensile strength from 0.75 MPa to 1.81 MPa, while elongation decreased to 28%. JKRB biofoil’s lower moisture content compared to chitosan biofoil was attributed to the formation of hydrogen bonds between chitosan biofoil and JKRB compounds, further confirmed with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The JKRB biofoil completely degraded in compost in 11 days. The future upscaled production of JKRB biofoil from biowastes for active packaging may support the fights against plastic waste, food waste, and the invasiveness of Japanese knotweed, while greatly contributing to the so-called ‘zero-waste’ strategy and the reduction in greenhouse gas emissions.

Integrated multiplatform-based metabonomics and network analysis to explore the mechanism of Polygonum cuspidatum on hyperlipidemia

Hyperlipidemia is a major risk factor and pathological basis for cardiovascular diseases. Polygonum cuspidatum (HZ), a famous traditional Chinese medicine, is frequently used to treat hyperlipidemia. However, little is known about its underlying mechanism. Herein, an integrated approach combining multiplatform-based metabonomics and network analysis was adopted to elucidate the ameliorative mechanism of HZ on hyperlipidemia. The global metabolomic characters of HZ on hyperlipidemia were investigated by GC-MS and LC-MS based metabonomics. Significant metabonomic alterations were observed in hyperlipidemic group, which could be restored by HZ supplementation. Furthermore, the drug-ingredients-target-metabolic pathway network was constructed, and the result indicated that HZ exhibited hypolipidemic efficacy through resveratrol, polydatin, torachrysone-8-O-β-D-(6'-oxayl)-glucoside, physciondiglucoside, (+)-catechin, β-sitosterol, quercetin, luteolin and physovenine acting on phospholipase A2, unspecific monooxygenase, arachidonate 15-lipoxygenase, aromatic-L-amino-acid decarboxylase, alcohol dehydrogenase and triacylglycerol lipase. In conclusion, this study explored potential mechanism of HZ on hyperlipidemia with the aid of the integrated approach combining multiplatform-based metabonomics and network analysis, which might provide a theoretical basis for the clinical application of HZ.

(-)-Epicatechin-An Important Contributor to the Antioxidant Activity of Japanese Knotweed Rhizome Bark Extract as Determined by Antioxidant Activity-Guided Fractionation

The antioxidant activities of Japanese knotweed rhizome bark extracts, prepared with eight different solvents or solvent mixtures (water, methanol, 80% methanol_(aq), acetone, 70% acetone_(aq), ethanol, 70% ethanol_(aq), and 90% ethyl acetate_(aq)), were determined using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Low half maximal inhibitory concentration (IC₅₀) values (2.632–3.720 µg mL⁻¹) for all the extracts were in the range of the IC₅₀ value of the known antioxidant ascorbic acid at t₀ (3.115 µg mL⁻¹). Due to the highest extraction yield (~44%), 70% ethanol_(aq) was selected for the preparation of the extract for further investigations. The IC₅₀ value calculated for its antioxidant activity remained stable for at least 14 days, while the IC₅₀ of ascorbic acid increased over time. The stability study showed that the container material was of great importance for the light-protected storage of the ascorbic acid_(aq) solution in a refrigerator. Size exclusion–high-performance liquid chromatography (SEC-HPLC)–UV and reversed phase (RP)-HPLC-UV coupled with multistage mass spectrometry (MSⁿ) were developed for fractionation of the 70% ethanol_(aq) extract and for further compound identification, respectively. In the most potent antioxidant SEC fraction, determined using an on-line post-column SEC-HPLC-DPPH assay, epicatechin, resveratrol malonyl hexoside, and its in-source fragments (resveratrol and resveratrol acetyl hexoside) were tentatively identified by RP-HPLC-MSⁿ. Moreover, epicatechin was additionally confirmed by two orthogonal methods, SEC-HPLC-UV and high-performance thin-layer chromatography (HPTLC) coupled with densitometry. Finally, the latter technique enabled the identification of (−)-epicatechin. (−)-Epicatechin demonstrated potent and stable time-dependent antioxidant activity (IC₅₀ value ~1.5 µg mL⁻¹) for at least 14 days.

Resveratrol: A Double-Edged Sword in Health Benefits

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) belongs to polyphenols' stilbenoids group, possessing two phenol rings linked to each other by an ethylene bridge. This natural polyphenol has been detected in more than 70 plant species, especially in grapes' skin and seeds, and was found in discrete amounts in red wines and various human foods. It is a phytoalexin that acts against pathogens, including bacteria and fungi. As a natural food ingredient, numerous studies have demonstrated that resveratrol possesses a very high antioxidant potential. Resveratrol also exhibit antitumor activity, and is considered a potential candidate for prevention and treatment of several types of cancer. Indeed, resveratrol anticancer properties have been confirmed by many in vitro and in vivo studies, which shows that resveratrol is able to inhibit all carcinogenesis stages (e.g., initiation, promotion and progression). Even more, other bioactive effects, namely as anti-inflammatory, anticarcinogenic, cardioprotective, vasorelaxant, phytoestrogenic and neuroprotective have also been reported. Nonetheless, resveratrol application is still being a major challenge for pharmaceutical industry, due to its poor solubility and bioavailability, as well as adverse effects. In this sense, this review summarized current data on resveratrol pharmacological effects.

Isolation and purification of two antioxidant isomers of resveratrol dimer from the wine grape by counter-current chromatography

Resveratrol dimers belong to a group of compounds called stilbenes, which along with proanthocyanidins, anthocyanins, catechins, and flavonols are natural phenolic compounds found in grapes and red wine. Stilbenes have a variety of structural isomers, all of which exhibit various biological properties. Counter-current chromatography with a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (2:5:4:5, v/v/v/v) was applied to isolate and purify stilbene from the stems of wine grape. Two isomers of resveratrol dimers trans-ε-viniferin and trans-δ-viniferin were obtained from the crude sample in a one-step separation, with purities of 93.2 and 97.5%, respectively, as determined by high-performance liquid chromatography. The structures of these two compounds were identified by (1) H and (13) C NMR spectroscopy. In addition, their antioxidant activities were assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The antioxidant activities of trans-δ-viniferin were higher than that of trans-ε-viniferin in this model. This work demonstrated that counter-current chromatography is a powerful and effective method for the isolation and purification of polyphenols from wine grape. Additionally, the DPPH radical assay showed that the isolated component trans-δ-viniferin exhibited stronger antioxidant activities than trans-ε-viniferin and a little bit weaker than vitamin E at the same concentration.

Comparative analysis of chemical constituents, antimicrobial and antioxidant activities of ethylacetate extracts of Polygonum cuspidatum and its endophytic actinomycete, Streptomyces sp. A0916

The present study investigated the chemical composition of ethylacetate extracts from an endophytic actinomycete Streptomyces sp. A0916 and its host Polygonum cuspidatum. A comparative analysis of the antimicrobial and antioxidant properties of the extracts was also conducted. 32 compounds of P. cuspidatum and 23 compounds of Streptomyces sp. A0916 were isolated and identified by GC/MS. Antimicrobial activities of the extracts were evaluated using eight microbial strains (3 Gram-positive bacteria, 3 Gram-negative bacteria, and 2 fungi). The Streptomyces sp. A0916 extracts showed a wide range of antimicrobial activities and presented greater antimicrobial effectiveness than the P. cuspidatum extracts. The minimum inhibitory concentration (MIC) of Streptomyces sp. A0916 extracts against the ampicillin-resistant strain Enterococcus faecium SIIA843 was 32 μg·mL(-1). Furthermore, the extracts had greater antimicrobial effect against Gram-positive bacteria than Gram-negative bacteria. Finally, the antioxidant activity of the Streptomyces sp. A0916 extracts was equal to that of the P. cuspidatum extracts. In conclusion, our results suggest that the endophytic actinomycetes of the medicinal plants are an important source of bioactive substances.