Transformation of ginsenosides by moderate heat-moisture treatment and their cytotoxicity toward HepG2 cells

Abstract

In the current study, the effects of heat-moisture treatment on the ginsenoside contents and ginsenoside compositions such as Rg3, CK and Rb1 etc. were investigated at different temperatures, relative humidities (RHs) and treatment times. Our findings demonstrated that the highest total ginsenoside content was 7.48% after 12 days treatment at temperature 80 °C and RH 75%. Correspondingly, less polar ginsenosides Rg3 and CK were accumulated increasingly from 0.88 mg/g and 0.84 mg/g to 7.30 mg/g and 15.08 mg/g, respectively, during heat-moisture treatment. Compared to the ginsenoside extracts of untreated ginseng (UGE), the ginsenoside extracts of heat-moisture treated ginseng (HMGE) exerted better scavenging activities of 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS+), and hydroxyl (OH) radicals, as well as higher cytotoxicity efficiency against HepG2. In addition, HMGE promoted cell apoptosis by up-regulating the related protein expression, especially the caspase-3, caspase-9, and poly (ADP-ribose) polymerase (PARP). Therefore, the cytotoxicity of HMGE against HepG2 cells may be due to the mitochondrial apoptosis pathway induced by up-regulated caspase. These results strongly proved the promising prospect of HMGE as functional food or ingredient in nourishing or disease chemoprevention.