Evaluation of In Vitro Anticancer Activity and Apoptotic Potential of Wrightia Tinctoria Bark Extracts on Oral Cancer Cell Lines

Abstract

Background and objectives: Bioprospecting of indigenous plants for biological/cytotoxic properties has become an area of growing interest in cancer research. Wrightia tinctoria is a lesser-studied plant widely distributed in India which is commonly used in traditional medicinal systems like Ayurveda and Siddha and holds potential as a source for novel therapeutic agents. In this study, the cytotoxic effects of Wrightia tinctoria bark extracts on oral cancer (KB) cell lines were evaluated, focusing on three different extraction solvents ethanol, ethyl acetate, and water. The present study aimed to evaluate and compare the cytotoxic effects of Wrightia tinctoria bark extracts, while also investigating their potential to induce apoptosis which can contribute into exploration of new plant based anticancer agents. Methods: Cytotoxic effects of ethanol, ethyl acetate, and aqueous extracts of Wrightia tinctoria bark were evaluated on human oral cancer cells (KB cell line). Cell viability was assessed by 3-(4,5-dimethylthiazoline-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay). Apoptosis was evaluated by acridine orange (AO) and ethidium bromide (EB) double staining method and expression of apoptotic enzymes Caspase 3 and Caspase 7 were measured by quantitative indirect ELISA technique. Results: Ethanol extract of Wrightia tinctoria bark exhibited highest cytotoxic activity towards oral cancer cell lines. The half-maximum inhibitory concentration (IC50) values of the ethanol, ethyl acetate, aqueous extracts were 75.084µg/ml, 179.743µg/ml and 115.258 µg/ml respectively. IC 50 concentration of ethanol and ethyl acetate extracts stimulated significant apoptosis in KB cells. Indirect ELISA showed increased expression of caspase 3 and caspase 7 among the cells on treatment with ethanol and ethyl acetate extracts. Conclusion: Ethanol extract of Wrightia tinctoria bark exhibited highest cytotoxic activity towards oral cancer cell lines and induced apoptotic changes. Further research may help us to identify newer, better anti cancer agents against oral cancer from Wrightia tinctoria bark.