In vitro screening of antioxidant and antimicrobial activities of medicinal plants growing in Slovakia

Abstract

Traditional medicine usage at the preventive medicine level is comprehensive and plant-based remedies are being prescribed for the treatment of a large scale of diseases by indigenous medical practitioners around the world. The phytochemicals being observed in the fruits and vegetables as well as herbal plants are getting investigated intensively as their important role in the avoidance of diverse human diseases is undoubtful. Antioxidant and antimicrobial activities of selected medicinal herbs were evaluated in this study. Aerial parts of plants from Hypericaceae, Lamiaceae, Fabaceae, Plantaginaceae, Rubiaceae growing wild in Slovakia (locality Zobor) were investigated to characterize their polyphenol content, flavonoid content, as well as antioxidant and antimicrobial activity. Inspection of the metabolic profile combined with HPLC data showed that the ethanol extract contained mainly eight polyphenols with apigenin, daidzein, kaempferol, rutin, quercetin, vitexin, and cynaroside as the main chemicals. Among them, neochlorogenic acid, chlorogenic acid, trans-p-caffeic acid, trans-p-coumaric acid, trans-p-sinapic acid, trans-p-ferulic acid, rosmarinic acid were identified. The antioxidant capacity of ethanol extracts was evaluated by employing DPPH radical scavenging and phosphomolybdenum assays. All samples were also tested against Gram-positive (Staphylococcus aureus, Bacillus thuringiensis, Micrococcus luteus, Staphyloccocus epidermidis) and Gram-negative (Citrobacter koseri, Escherichia coli, Pseudomonas proteolytica, Hafnia alvei, Salmonella enterica, Yersinia enterocolitica) bacterial species using the disk diffusion and minimum inhibitory concentration assays.