Isolation and Characterization of Gallic Acid and Methyl Gallate from the Seed Coats of Givotia rottleriformis Griff. and their Anti-Proliferative Effect on Human Epidermoid Carcinoma A431 Cells

In this study we have isolated and chemically characterized the bioactive compounds GA and MG from the bioassay guided methanolic (MeOH) seed coat extracts of G. rottleriformis. The fractions obtained from open silica column chromatography were subjected to in vitro enzymatic assays. Among seven fractions we found that only fraction 5 and 6 showed significant inhibition activity towards COX-1 with an IC50 value of 28μg/mL and 9.3μg/mL and COX-2 with an IC50 value of 35/mL and 7.0μg/mL respectively. However, we could not find 5-LOX enzyme inhibition activity. MG (10mg/g DW) and GA (6mg/g DW) were the major compounds of seed coats. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, which showed that GA/MG significantly reduced the growth of A431 cells with an IC50 value of 25μg/mL and 53μg/mL and 11μg/mL and 43μg/mL at 24h and 48h, respectively. However the cytotoxic effect of GA/MG on HaCaT normal skin keratinocyte cell line was found to be less. Western blot analysis has shown that GA/MG treatment down regulated Bcl-2 and up regulated cleaved caspase-3 with respect to increasing doses. Our results conclude that GA and MG have potential anticancer effects and can be used as therapeutic agents for skin cancers. Graphical abstract
Source: Toxicology Reports - Category: Toxicology Source Type: research