Mechanistic Exploration of the anticancer activity of Justicia adhatoda Plant Leaf Ethanolic Extract against Colon Cancer Cells: An in silico and in vitro Approach

OBJECTIVE: Being the 3rd most prevalent cancer, colorectal cancer (CRC) has a high rate of mortality, a poor prognosis, and a clinical outcome. Treatment with commercial synthetic anti-cancer drugs also imparts a number of co-morbidities, further complicating the condition. Hence, there is a need to identify a potential anticancer agent to decrease the mortality rate and provide better clinical outcome in CRC patients. Pharmacologically active agents from natural sources are the currently recognized alternatives to synthetic drugs due to their minimal toxicity. In this study, a widely recognized plant, Justicia adhatoda (JA), traditionally used for treating respiratory ailments and rich in anti-inflammatory potential, was used to investigate its antiproliferative property against CRC. MATERIALS & METHODS: Preliminary phytochemical screening, GCMS, Antioxidant assay, anti-inflammatory assay, cell culture -MTT assay, fluorescence staining assay, and protein and gene expression analysis. RESULTS: The ethanolic extract of JA showed a strong cytotoxic effect on the cancer cells. The results of fluorescence staining show that the JA extract impart reactive oxygen species (ROS) -mediated apoptosis in proliferating cells by increasing ROS generation. This was further confirmed by evaluating the protein level of the antioxidant reservoirs and oxidative/inflammatory markers, which upon treatment were found to decrease and increase, respectively. This imbalance is attributed to the activation of the intrinsic apoptosis pathway, by altering the levels of pro- and anti- apoptotic genes in the cells and ultimately leading to cell death. The in silico analysis of pharmacokinetics, toxicity and molecular docking suggests that JA phytoconstituents show drug-like qualities and a promising activity against cancer. CONCLUSION: Overall, the findings suggest that JA ethanolic extract could be an effective anticancer agent against HT-29 colon adenocarcinoma cells.