Investigation of in-vitro antioxidant and cytotoxic potential of methanol extract of begonia roxburghii leaves

Abstract

Begonia roxburghii (B. roxburghii) is a medicinal plant that belongs to Begoniaceae family which is commonly known as East Himalayan Begonia. Literature review revealed that, the leaves of this plant have been widely used as drug or component of drug to cure various gastrointestinal disorders like diarrhea, bile dysentery, stomach ache and skin diseases. Literature data also revealed that, the leaf extract possess therapeutic effects such as antimicrobial activity in order to prevent the growth of harmful microorganisms as well as antioxidant and cytotoxic potential in order to suppress the growth of cancer cells in human body. The current study was aimed to investigate the in-vitro antioxidant and cytotoxic potential of methanol extract of B. roxburghii by standard methods that had not been previously conducted. In this study, the methanolic extract of the leaf of B. roxburghii was screened for the identification of certain phytocompunds named as tannins, alkaloids, flavonoids, glycosides, resins, steroids, carbohydrates and phenols which provide definite pharmacological actions on human body. In this study, four methods were used for instance, DPPH free radical scavenging assay, total phenolic content, total flavonoid content and total antioxidant capacity for the determination of in-vitro antioxidant potential. With the increase in concentration, the % of inhibition of DPPH, total phenolic content, total flavonoid content and total antioxidant capacity also increased. In case of DPPH free radical scavenging assay, the highest % of inhibition, 89.92 % was obtained at the highest concentration of 1200 μg/mL. At the highest concentration of 1200 μg/mL the leaf extract showed remarkable value of total phenolic content and antioxidant capacity which was expressed as 100.58 mg of gallic acid per gram of dried extract and 98.58 mg of ascorbic acid per gram of dried extract respectively. Along with that, in-vitro cytotoxic potential of the leaf extract was also assessed by MTT assay at different concentrations of (25 mg/mL, 2.5 mg/mL, 0.25 mg/mL, 0.025 mg/mL) of B. roxburghii leaf extract against HeLa cell line (Cervical cancer cell line). The cytotoxicity test revealed that, at the highest concentration of 25 mg/mL, methanolic extract of B. roxburghii leaves showed 80 % of the cell death whereas HeLa cell survival was only 20 % at that concentration. Therefore, antioxidant potential was significant in three methods whereas cytotoxic potential was not that much significant. However, further investigation can also assist to invent unfamiliar properties and unexplored pharmacological activities of this plant as well as to familiarize the plant as a new source of medicine.