Gentians, natural remedies for future of visceral pain control; an ethnopharmacological review with an in silico approach.

Different gentian preparations are used as traditional remedies for internal pain control in: Persian traditional medicine (PTM), Chinese traditional medicine (CTM) and Ancient Greek medicine (AGM) from the time of the Roman Empire. Objective: To present a survey of the ethnopharmacological applications of gentians recorded as being used in Eastern and Western traditional medical systems (PTM, CTM and AGM) and their pharmacological effects, chemical composition as well as an in silico investigation of the possible active component/s for the alleviation of internal pain via molecular docking studies. Major traditional medicine literature (PTM, CTM and AGM, 50 AD- 1770) and ethnobotanical studies for the application of gentians were reviewed. Nine European species representing 5 of the 13 sections currently attributed to Gentiana were selected. Chemical compounds and pharmacological activity data of these species were gathered from different databases including Google Scholar, PubChem, PubMed and Web of Science (between 1972 and 2020). The possible active constituents of gentians on visceral pain receptors were investigated, in silico. In all investigated literature, traditional uses of gentian were indicated to have anti-nociceptive effects on visceral pain and possess diuretic action. According to our computational study, acylated flavonoid glycosides, viz. trans-feruloyl-2"-isovitexin (33), trans-feruloyl-2"-isovitexin-4'-O-ß-D-glucoside (34), iso-orientin-4'-O-glucoside (38), trans-caffeoyl-2"-iso-orientin-4'-O-ß-D-glucoside (39), iso-orientin-2"-O-ß-D-glucoside (40) and isoscoparin (41), might be responsible for visceral pain reduction by interacting with the purinergic receptor (P2X3) and vanilloid receptor 1 (TrpV1). This finding shows a good correlation with different traditional gentian uses in Persian, Chinese and European ethnomedicine for visceral pain control.

Validated methods for the quantification of biologically active constituents of poplar-type propolis.

The validation of rapid, low-cost spectrophotometric procedures for the quantification of the three main groups of bioactive substances (flavones and flavonols, flavanones and dihydroflavonols, and total phenolics) in poplar-type propolis has been performed. A spectrophotometric assay based on the formation of an aluminium chloride complex was applied for the quantification of total flavones and flavonols using galangin as standard. Because of the high amount of flavanones and dihydroflavonols in "poplar type" propolis, the introduction of a distinct procedure for their quantification was considered of special significance and the DAB9 colorimetric method was applied for the purpose. Total phenolic content was measured by the Folin-Ciocalteu procedure using a mixture of pinocembrin and galangin as a reference. The procedures were validated using a model mixture of compounds representing the poplar-type propolis composition as found in previous studies. The accuracy (recovery) varied in the range 84-109%, and the relative standard deviation was 0.5-6.2%. The developed spectrophotometric procedures were applied to six poplar type propolis samples. The results were verified independently by a HPLC procedure. The two sets of results agreed satisfactory, as proven by Student's t-test.