In vitro α-Glucosidase Inhibitory, Antioxidant and Anti-Colorectal Cancer Activities of Gourd (Coccinia grandis) Stems Fractions and its Compounds

Plant-derived agents from a medicinal plant Coccinia grandis, are known to have a considerably effect on several bioactivities. This present study evaluated the identified compounds on stem fractions of C. grandis through their antioxidant, anti-diabetes mellitus, and anti-colorectal cancer properties. Dried of C. grandis stems from Thailand were macerated with methanol and then fractionated with n-hexane and ethyl acetate. Each fraction was then assayed for antioxidant activities, anti-diabetes agent using rat intestinal a-glucosidase, and anti-colorectal cancer properties on HCT116 and SW620 cell lines. Ethyl acetate fractions were then subjected to further fractionation and compound identification. There were 7 identified compounds including caffeic acid, p-hydroxycoumaric acid, ferulic acid, 4-hydroxybenzaldehyde, methyl caffeate, syringaldehyde and vanillic acid. Methyl caffeate (IC50= 0.145mM) and ferulic acid (IC50= 0.057mM) have significant DPPH and ABTS radical scavenging activity, respectively. Caffeic acid had the strongest α-glucosidase inhibitory activity through both maltase (IC50= 0.732mM) and sucrase (IC50= 0.111mM), however it was not all that different from methyl caffeate. Methyl caffeate (IC50= 0.001mM) and caffeic acid (IC50= 0.085mM) exhibited anti-colorectal cancer effects against HCT116 and SW620, respectively. The kinetic investigation of methyl caffeate indicated that it retarded maltase function in a competitive manner and sucrase function in an uncompetitive manner. Regarding the results, it demonstrated that certain active compounds of C. grandis stems have their promising action on those bioactivities assay and have potent charges as drug candidates against oxidative stress, diabetes mellitus, and colorectal cancer diseases.