Determination of Antimicrobial, Cytotoxic and Antioxidant Activity in Extracts of Hemidesmus indicus (L.) R. Br.

Abstract

There is a growing interest in use of natural antioxidants instead of synthetic antioxidants due to its versatile health benefits. Hemidesmus indicus (L.) R. Br. is one of the most commonly used medicinal plants in traditional medicine due to its phytochemicals. The present study was conducted to evaluate antimicrobial, cytotoxic and antioxidant activities in 85% ethanol and hot water extracts of root and leaves of H. indicus. Total phenolic content, total flavonoid content and radical scavenging activity of both crude extracts were determined using Folin-Ciocalteu method, Aluminium chloride method and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay respectively. Anti-microbial properties of crude extracts were studied against Escherichia coli and Staphylococcus aureus using agar disk diffusion method. The cytotoxicity level of crude extracts against E. coli and S. aureus was evaluated using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Ethanol extracts of both root and leaves of H. indicus exhibited a higher phytochemical content than hot water extracts. Between ethanol extracts, H. indicus roots showed higher total phenolic content and total flavonoid content than H. indicus leaves, which were 309.0±2.6 mg gallic acid equivalent (GAE) per 100 g of dry weight of sample and 34.4±0.2 mg rutin equivalent (RT) per 100 g of dry weight of sample respectively. The highest radical scavenging activity was detected in H. indicus roots with IC50 at 0.26 mg/ml. The disk diffusion assay revealed an antimicrobial activity only for ethanol extracts, where H. indicus leaves showed a significant activity only against S. aureus. Moreover, ethanol extracts of H. indicus roots showed a significant cytotoxic activity against E. coli with the IC50 value of 4.4±0.2 mg/ml. This study revealed antimicrobial, cytotoxic and antioxidant properties of crude extracts of H. indicus exhibiting a new hope for a natural source of antioxidants and antimicrobial compounds for food and pharmaceutical industries.
Keywords: Hemidesmus indicus (L.) R. Br., Antioxidants, Cytotoxicity