Phytochemical analysis and antimicrobial activity of different solvent extracts of stem of Cynanchum viminale (L.) L. (Muwakeeriya)

Abstract

In Sri Lanka, traditional healers use the Cynanchum viminale for treatment of various diseases associated with microbial infections. Although medicinal activities of many plants have been well documented in Sri Lanka, there is very less information about C. viminale. With this background, the present study aimed to elucidate antimicrobial activity and to analyse phytochemicals of ethyl acetate and water extracts of stem of C. viminale. The antimicrobial assays were carried out by agar well diffusion method using crude extracts (100 mg/ 100 μL). Five different bacterial species and three different Candida species were screened. Streptomycin sulphate (50 ng/100 μL) and Fungicon (100 ng/100 μL) were used as positive control for bacteria and Candida species, respectively. The phytochemical analysis showed positive to tannins, saponins, phlobatannins, flavonoids, cardiac glycosides, alkaloids, terpenoids and steroids. Ethyl acetate extract showed highest activity against the bacteria Escherichia coli (ATCC 25922) with diameter of inhibition zones 26.9 ± 1.4 mm and it also showed anti-candida activity against all tested Candida species and the highest activity (19.03±0.34) was against C. krusei. The present study confirmed the antimicrobial activity of C. viminale and revealed the major groups of phytochemicals in the extracts. Further studies are needed to find out the active compounds in these extracts.