Terminalia chebula Retz. (Fam. Combretaceae), locally called Manahei, is a well-known medicinal plant that grows wildly in Manipur, a Northeastern state of India. It is used as a mild laxative, an anti-inflammatory agent, and a remedy for piles, colds, and ulcers by ethnic communities of the state. The hydroalcoholic extract obtained from four fruit samples of T. chebula collected from different locations in Manipur were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-performance thin-layer chromatography (HPTLC) for their chemical constituents and evaluated for their anticancer activity against the colon cancer cell HCT 116. GC-MS analysis results indicated significant variation in the composition and percentage of major compounds present in the extracts. 1,2,3-Benzenetriol was the most abundant chemical constituent present in all four extracts of T. chebula, ranging from 20.95 to 43.56%. 2-Cyclopenten-1-one, 5-hydroxymethylfurfural, and catechol were commonly present in all extracts. Two marker compounds, gallic acid and ellagic acid, were also quantified usingHPTLC in all four extracts of T. chebula. The highest content of gallic acid (22.44 ± 0.056 µg/mg of dried extract) was observed in TCH, and that of ellagic acidwas found in TYH (11.265 ± 0.089 µg/mg of dried extract). The IC50 value of TYH for the DPPH and ABTS assays (12.16 ± 0.42 and 7.80 ± 0.23 µg/mL) was found to be even lower than that of Trolox (18 ± 0.44 and 10.15 ± 0.24 µg/mL), indicating its strong antioxidant properties among the four extracts of T. chebula. The MTT assay determined the effect of T. chebula extracts on the viability of HCT 116 cells. TYH showed the highest activity with anIC50 value of 52.42 ± 0.87 µg/mL, while the lowest activity was observed in TCH (172.05 ± 2.0 µg/mL). The LDH assay confirmed the cytotoxic effect of TYH in HCT 116 cells. TYH was also found to induce caspase-dependent apoptosis in HCT 116 cells after 48 h of treatment. Our study provides insight into the diversity of T. chebula in Manipur and its potential activity against colon cancer.
Keywords: GC-MS; HCT 116; HPTLC; Terminalia chebula Retz.; cytotoxicity; north east India.