Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour)

Cell extraction method coupled with LC-QTOF MS/MS analysis for predicting neuroprotective compounds from Polygonum tinctorium

The cell extraction method coupled with LC-QTOF-MS/MS is a biological screening technique in which cells are incubated with extracts of natural products, which results in potential bioactive compounds selectively combining with various extracellular and intracellular targets. Although the neuroprotective effects of the plant Polygonum tinctorium are unknown, the ethyl acetate (EtOAc) fraction exhibits significant neuroprotective effects against ʟ-glutamate-induced cytotoxicity in HT22 cells. In this study, we attempted to identify the neuroprotective compounds in the EtOAc fraction of P. tinctorium using the cell extraction method coupled with LC-QTOF MS/MS. Potential neuroprotective components derived from P. tinctorium were combined selectively with HT22 cells, and cell-derived metabolites were identified. A new flavonoid compound, 3,5,3',4'-tetrahydroxy-6,7-methylendioxyflavone-3-O-β-ᴅ-glucopyranoside (1), and 14 known compounds (2-15), with compounds 2, 3, 8, 13, and 15 detected by the cell extraction method, were isolated from the EtOAc fraction of P. tinctorium. Compounds 2, 8, 12, and 14 showed strong neuroprotective effects, with compounds 2 and 14 identified in this plant for the first time in this study. Our results indicate that the cell extraction method coupled with LC-QTOF MS/MS is a useful tool for screening and identifying neuroprotective compounds in natural products.

Persicaria hydropiper (L.) Delarbre: A review on traditional uses, bioactive chemical constituents and pharmacological and toxicological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Various plant parts of Persicaria hydropiper (L.) Delarbre (Syn.: Polygonum hydropiper L., Family: Polygonaceae) are used in traditional medicine systems as astringent, sedative, antiseptic and also for the treatment of respiratory disorders, edema and snake bites. It is also used as a spice in many Asian countries.

AIM OF THE REVIEW

The main aim of this review is to critically analyze the reported traditional uses, bioactive chemical constituents and pharmacological activities of P. hydropiper.

MATERIALS AND METHODS

Scientific database including PubMed, Scopus, SciFinder and secondary resources including books and proceedings were searched using relevant terminologies related to P. hydropiper and available scientific information was critically analyzed.

RESULTS

Analysis of the scientific literature regarding the traditional uses revealed that P. hydropiper is used as a medicine and as spice in food preparations in various parts of the world. Various compounds including flavonoids, phenylpropanoid derivatives, and sesquiterpenoids among others were reported as active compounds. The extracts and compounds from P. hydropiper showed diverse biological activities including anti-inflammatory, antioxidant, cytotoxic, antimicrobial activities, etc. CONCLUSION: Although various research reports showed diverse biological activities for extracts and compounds obtained from P. hydropiper, very few studies were performed using animal models. Many of these studies also lacked proper experimental setting such as use of positive and negative controls and selection of dose as in most of these studies very high doses of extracts were administered. Further, as P. hydropiper is widely used in the treatment of snake bites and insect bites, such effects of extracts and/or compounds are not well explored. Future studies on P. hydropiper should be focused to establish the links between the traditional uses, active compounds and reported pharmacological activities.

A new sucrosephenylpropanoid ester from Polygonum pubescens Blume

The present study investigated the chemical constituents of aerial part of Polygonum pubescens Blume. Twenty-two compounds 1-22 were obtained from petroleum ether and ethyl acetate extracts of aerial part of P. pubescens, including a new phenylpropanoide esters 1 and 21 known compounds. The structures were determined on the basis of spectroscopic and chemical methods. Sixteen compounds were assessed for their cytotoxic and anti-inflammatory activities. Several compounds showed effects on different targets.