BACKGROUND: Non-alcoholic fatty liver disease (NAFLD, recently renamed as metabolic dysfunction-associated steatotic liver disease [MASLD]) has emerged as one of the most prevalent chronic liver diseases globally. The more severe progressive form of the disease is called nonalcoholic steatohepatitis (NASH, now termed metabolic dysfunction-associated steatohepatitis [MASH]). The rising prevalence of NASH is placing an increasing burden on global healthcare systems also associated with a significant economic costs. Alternate-day fasting (ADF) as a nutritional intervention, has demonstrated potential in relieving symptoms associated with multiple metabolic syndromes, however, its clinical applicability is limited by hypoglycemia risk and poor long-term adherence. Therefore, pharmacological interventions are still needed, for thousands of years, natural products have been extensively utilized in human disease research.
PURPOSE: This study aimed to investigate the hepatoprotective effect and underlying mechanism of BS012 (a 70 % ethanol extract of Platycodon grandiflorum, Cinnamomum cassia, and Asiasarum sieboldii mixed in the ratio of 2:2:1) in the development of NASH.
EXPERIMENTAL METHODS: 3T3-L1 adipocytes were treated with various doses of BS012 (1, 5, and 10 μg/ml). Male C57BL/6 N mice were exposed to fructose, palmitate, and cholesterol (FPC) diet, in conjunction with 42 g/l high fructose corn syrup (HFCS) water for a duration of 6 months to induce NASH. Applied ADF management or oral administration of three doses (100, 200, and 300 mg/kg) of BS012 to the mice to evaluate its effect. Serum lipid parameters, biochemical markers of liver damage, and pro-inflammatory cytokines were analyzed. Liver histological analyses were conducted to check the morphologic changes. Signaling pathways related with lipid metabolism, inflammation, apoptosis, and fibrosis in the liver were investigated using western blot.
RESULTS: BS012 treatment effectively reduced the intracellular lipid droplets accumulated in 3T3-L1 cells. In 6 months of the dietary intervention induced NASH mice model, it was found a remarkable increment in body, liver, and perigonadal fat weight, accompanied by significantly up-regulated hepatocellular steatosis, apoptosis, inflammation, and fibrosis levels. BS012 treatment effectively reduced the growth rate of both body and organ weights, ameliorated level of serum biochemical markers associated with dyslipidemia and liver damage, and suppressed the expression of pro-inflammatory cytokines. Furthermore, BS012 treatment diminished hepatic lipid accumulation, enhanced fatty acid oxidation level, and consequently mitigated hepatic steatosis, also significantly inhibited the expression of pro-inflammatory factors, and markedly reduced apoptosis response and fibrosis progression in NASH development.
CONCLUSION: The FPC diet combined with HFCS induced a NASH mouse model that closely mimics the relevant pathology of human NASH within 6 months, BS012 markedly attenuated these pathological features, with the observed protective effects attributed to the reduction of hepatic steatosis through modulation of ChREBP-α- and AMPK-mediated lipid synthesis and fatty acid oxidation pathways. In addition, BS012 suppressed the TLR-4/NF-κB signaling pathway, thereby alleviating inflammation, as well as reducing hepatic apoptosis responses, and attenuating the progression of liver fibrosis via inhibition of the TGF-β/Smad signaling pathway. The synergistic interaction among the botanical components of BS012 is believed to act on multiple molecular targets, enhancing therapeutic efficacy through complex regulatory mechanisms, which collectively contribute to the mitigation of liver injury thereby offering protection against NASH progression. BS012, a novel combination of three medicinal herbal extracts, holds promise as a potential therapeutic candidate for the treatment of NASH.
