Hibiscus sabdariffa extract improves hepatic steatosis, partially through IRS-1/Akt and Nrf2 signaling pathways in rats fed a high fat diet.

Non-alcoholic fatty liver disease (NAFLD) has become a major world-wide health problem and is characterized by lipid accumulation in the liver induced by high fat diet (HFD) consumption. It is usually associated with inflammation, oxidative stress, and insulin resistance. Roselle extract (Hibiscus sabdariffa) is an herb which is used in traditional medicine. However, further study is necessary to represent the mechanism of NAFLD and find new preventive strategies. This study aims to investigate the protective effects of roselle extract on NAFLD rat models. Male Sprague-Dawley rats (n = 35) were divided into 5 groups, control, HFD, HFD + Simvastatin (HFD + SIM), HFD + 250 mg/kg BW, and HFD + 500 mg/kg BW of roselle extract (HFD + R250 and HFD + R500, respectively). The results showed that roselle extract reduced hepatic lipid contents, de novo lipogenesis enzymes, microsomal triglyceride transfer protein, inflammatory cytokines, malondialdehyde, and increased antioxidant properties, transporter related with lipoprotein uptake, and insulin signal proteins. Comparing to SIM, the HFD + R500 group exhibited the greater benefit in terms of anti-hepatic steatosis, antioxidant properties, and an ability to improve insulin resistance. This study demonstrates that roselle extract improved antioxidant properties and attenuated hepatic steatosis, liver inflammation, oxidative stress, and insulin resistance in HFD-induced NAFLD in rats, which could be used for NAFLD prevention.

Hibiscus sabdariffa L. calyx extract prevents the adipogenesis of 3T3-L1 adipocytes, and obesity-related insulin resistance in high-fat diet-induced obese rats.

Roselle (Hibiscus sabdariffa) is reported to be beneficial in treating obesity which can develop into a range of metabolic disorders. The molecular mechanisms by which roselle extract works to prevent obesity-related insulin resistance remains poorly understood. We hypothesized that the roselle extract can decrease lipid accumulation and improve insulin resistance by downregulating adipogenesis. The aim of this study is to investigate the protective effect of roselle extract on the mechanism of adipogenesis and prevent complications of the obesity-related insulin resistance in high-fat diet-induced obese rats for 8 weeks. Male Sprague Dawley rats were divided into 4 groups: control (C), high-fat diet (HFD), high-fat diet supplemented with 250 mg/kg BW of roselle (R250), and high-fat diet supplemented with 500 mg/kg BW of roselle (R500). The results demonstrated that roselle had the potential to reduce body weight, food intake, lipid profiles, inflammatory cytokines, lipid peroxidation, serum leptin, insulin and duodenal glucose absorption, while significantly increased glucose uptake of adipose tissue and muscle when compared to the HFD group. Roselle can prevent lipid accumulation by suppressing differentiation of 3T3-L1 adipocyte by downregulating the adipogenic gene expression. The results of this study demonstrated that the molecular mechanism underlying the protective effect of roselle, could be an alternative approach for obesity-related insulin resistance prevention.