Assessment of Phytochemical Profile, Antioxidant, and Anticancer Activity Against Colon Cancer-HT-29: A Potent Therapeutic Medicinal Plant (Tarenna alpestris) in Megamalai Hills, Western Ghats, India.

Medicinal plants have long been recognized as a valuable source of human health due to their therapeutic potential in treating a variety of diseases. Tarenna alpestris, a plant native to the Megamalai Hills in the Western Ghats of India, has traditionally been used for numerous medicinal purposes. However, despite its extensive use in folklore, scientific validation of its therapeutic properties remains limited. This study aims to evaluate the phytochemical composition of Tarenna alpestris, assess its antioxidant properties, and explore its potential anticancer effects against HT-29 colon cancer cells. The phytochemical profile was determined using preliminary screening and gas chromatography-mass spectrometry (GC-MS). Antioxidant activity was measured through DPPH, FRAP, H₂O₂, and N₂O₂ assays. The anticancer effects were investigated using the MTT assay for cell viability, AO/EtBr staining for apoptosis detection, DAPI staining for nuclear fragmentation analysis, and flow cytometry for cell cycle analysis. The phytochemical analysis identified several bioactive compounds, including flavonoids, alkaloids, terpenoids, and phenolic acids. Sixteen phytocomponents were detected from the extract by GCMS analysis, the major compounds are 9-octadecynoic acid (21%), N-hexadecanoic acid (16%), methylene diamine, N,N'-diacetyl (15%), 1-allyl-cyclohexane-1,2-diol (11%) 2-methyl-6-methylene-octa-1,7-dien-3-ol (5%), squalene (4%), and lupeol (3%) respectively. The antioxidant assays demonstrated significant free radical scavenging activity, with IC50 values comparable to known antioxidant standards. The antioxidant enzymatic activity of Tarenna alpestris extract suggests a potent ability to neutralize reactive oxygen species and protect against oxidative damage. In vitro studies revealed that Tarenna alpestris extract significantly inhibited the proliferation of HT-29 colon cancer cells and induced apoptosis, based on concentration dependent manner. The concentration needed to inhibit 50% of cell growth, known as the IC₅₀ value, was found to be 26 ± 0.20 μg/mL. Additionally, cell cycle analysis showed G0/G1 phase arrest in treated cells. Tarenna alpestris exhibits a robust phytochemical profile with substantial antioxidant and anticancer properties. These findings support its potential as a therapeutic agent for cancer prevention and treatment. Further research, including in vivo studies, is warranted to fully elucidate its therapeutic efficacy and mechanisms of action.