A pharmacognostical study of Vernonia cinerea Less (Asteraceae) and evaluation of anti-inflammatory and antibacterial activities of stem

Abstract

Aim This study aimed to establish the pharmacognostical characteristics of leaf, stem and root of Vernonia cinerea, Asteraceae (ash-coloured fleabane), and to verify the anti-inflammatory and antibacterial activities of various extracts of the stem. Background V. cinerea (Asteraceae) is traditionally used to treat inflammation, diarrhoea, cough, smoking cessation, asthma, Parkinson's disease and leprosy. Materials and methods Leaf, stem and root and their powders were examined microscopically, and pharmacognostic standardization parameters were determined according to WHO guidelines. Extracts of different organs of the plant in petroleum ether, chloroform, ethanol, ethanol (50%) and water were prepared and examined by thin-layer chromatography. An antibacterial assay of the stem extracts for Staphylococcus aureus was performed. The anti-inflammatory activity of the same extracts was studied using a carrageenan-induced paw oedema model in Wistar rats. Results and conclusion Microscopic characterization of the different organs of the plant indicated the presence of trichomes, arrangement of vascular bundles (stem: radial, root: scattered), anomocytic and diacytic stomata, and wavy epidermal cells in stomata. The antibacterial assay indicated a zone of inhibition of 20 ± 0 and 19.33 ± 0.33 mm with alcoholic and chloroform extracts of V. cinerea leaf, respectively (extracts of stem showed a zone of inhibition of 21.00 ± 0.57 and 21.00 ± 0.57 mm, respectively). Diclofenac sodium and chloroform extract showed 11.11% inhibition of inflammation, whereas 16.66 and 13.33% inhibition were observed with alcoholic and hydroalcoholic extracts, respectively. Microscopic and pharmacognostic parameters aid in the identification and characterization of different organs of the plant. Traditional claims of antimicrobial and anti-inflammatory activities of the stem have been verified. Various extracts showed significant results for anti-inflammatory and antimicrobial action.