Ginseng Saponin Enriched in Rh1 and Rg2 Ameliorates Nonalcoholic Fatty Liver Disease by Inhibiting Inflammasome Activation

Nonalcoholic fatty liver disease (NAFLD) is becoming one of the most common chronic liver diseases in the world. One of the features of NAFLD is hepatic fat accumulation, which further causes hepatic steatosis, fibrosis, and inflammation. Saponins, the major pharmacologically active ingredients isolated from Panax notoginseng, contain several ginsenosides, which have various pharmacological and therapeutic functions. However, the ginsenoside-specific molecular mechanism of saponins in NAFLD remains unknown. This study aimed to elucidate the effects of ginseng saponin extract and its ginsenosides on hepatic steatosis, fibrosis, and inflammation and their underlying action mechanism in NAFLD. Mice were fed a fast food diet (FFD) for 16 weeks to induce NAFLD and then treated with saponin extract (50 or 150 mg/kg) for the remaining nine weeks to determine the effects of saponin on NAFLD. Saponin extract administration significantly alleviated FFD-induced hepatic steatosis, fibrosis, and inflammation. Particularly, saponin extract, compared with conventional red ginseng, contained significantly increased amounts of ginsenosides (Rh1 (10.34-fold) and Rg2 (7.1-fold)). In vitro Rh1 and Rg2 treatments exerted an anti-steatotic effect in primary hepatocytes, an antifibrotic effect in hepatic stellate cells, and anti-inflammatory and pro-mitophagy effects in immortalized mouse Kupffer cells. Mechanistically, saponin extract alleviated lipopolysaccharide-induced NLRP3 inflammasome activation by promoting mitophagy. In conclusion, saponin extract inhibited inflammation-mediated pathological inflammasome activation in macrophages, thereby preventing NAFLD development. Thus, saponin extract administration may be an alternative method for NAFLD prevention.

A Review of the Different Methods Applied in Ginsenoside Extraction From Panax ginseng and Panax quinquefolius Roots

Ginseng saponins, also called ginsenosides, are the main active ingredients of Panax ginseng and Panax quinquefolius and are often used as qualitative and quantitative markers in the regulation of ginseng products. Various methods have been used to extract the major ginsenosides, such as ginsenosides Rb1, Rb2, Rc, Rd, and Rf from P. ginseng and P. quinquefolius. The objective of this paper is to review the studies regarding the influence of different extraction systems on ginsenoside amount and pattern in P. ginseng and P. quinquefolius roots. Although traditional extraction methods, Soxhlet and heat reflux extractions, have many disadvantages, including long extraction times and low extraction efficiency, they are the most widely used methods for ginseng saponin extraction. The amount and pattern of ginsenosides found in P. ginseng and P. quinquefolius roots differ depending on the method of extraction. In particular, the total ginsenoside amount and extraction efficiency can be significantly increased with the use of advanced extraction techniques that apply the conditions of high temperature and/or high pressure, such as pressurized liquid extraction, high-pressure microwave-assisted extraction, supercritical fluid extraction, and pulsed electric field extraction. Among several advanced extraction procedures, ultrahigh-pressure extraction is thought to offer the most advanced and efficient technology in that it requires only a few minutes for ginseng saponin extraction.