Phenolic acid composition and anticancer activity against human cancer cell lines of the commercially available fermentation products of Houttuynia cordata

A number of Houttuynia cordata fermentation products are commercially available in Thailand. However, their anticancer activity remains to be investigated. In this study, the phenolic acid composition and anticancer activity of two commercialized H. cordata fermentation products were investigated. Reversed phase HPLC was used to identify and quantify phenolic acids. MIT and Annexin V staining assays were used to investigate antiproliferative and apoptosis induction activities, respectively. Seven phenolic acids including protocatechuic, p-hydroxybenzoic, vanillic, syringic, p-coumaric, ferulic, and sinapinic acids were detected in the water-soluble constituents of both fermentation products 1 and 2. Water-soluble constituents of fermentation product 2 containing a greater phenolic acid content were more effective than product 1 in inhibiting the growth of HeLa, HCT116, and HT29 cells in a dose- and time-dependent manner. The non-cancer cell line Vero cells appeared to be resistant to both fermentation products. The growth inhibitory effects of both fermentation products in HeLa, HCT116, and HT29 cells included induction of apoptosis. These results suggest that commercially available fermentation products of H. cordata contain several anticancer phenolic acids that may be beneficial in the treatment of human cancer.