Rhododendron oldhamii leaf extract improves fatty liver syndrome by increasing lipid oxidation and decreasing the lipogenesis pathway in mice

Abstract

Some members of Rhododendron genus are traditionally used as medicinal plants for arthritis, acute and chronic bronchitis, asthma, pain, inflammation, rheumatism, hypertension and metabolic diseases. To the best of our knowledge, there is no report on the protective effects of R. oldhamii leaf extract on non-alcoholic fatty liver disease (NAFLD) in vivo and in vitro. In this study, the effects of R. oldhamii leaf extract on inhibiting the free fatty acid (FFA)-induced accumulation of fat in HepG2 cells and on improving fatty liver syndrome in mice with high fat diet (HFD)-induced NAFLD were investigated. For the in vitro assay, HepG2 cells were treated with FFAs (oleate/palmitate = 2:1) with or without treatment with R. oldhamii leaf ethyl acetate (EtOAc) fraction to observe lipid accumulation using Nile red and oil red O stains. For the in vivo assay, C57BL/6 mice were randomly assigned to three groups (n = 5), including the normal diet group, the HFD group and the HFD+EtOAc group. After 11 weeks, body weight, serum biochemical indices and the mRNA expressions of the liver tissue, as well as the outward appearance, weight and histopathological analysis of liver and adipose tissues were evaluated. Among the fractions derived from R. oldhamii leaf, the EtOAc fraction exhibited a strong fat-accumulation inhibitory activity. Following reverse-phase high-performance liquid chromatography (HPLC), four specific phytochemicals, including (2R, 3R)-astilbin (AS), hyposide (HY), guaijaverin (GU) and quercitrin (QU), were isolated and identified from the EtOAc fraction of R. oldhamii leaf extract. Among them, AS and HY showed excellent fat-accumulation inhibitory activity. Thus, the EtOAc fraction of R. oldhamii leaf and its derived phytochemicals have great potential in preventing FFA-induced fat accumulation. In addition, the EtOAc fraction of R. oldhamii leaf significantly improved fatty liver syndrome and reduced total cholesterol (TC) and triglyceride (TG) in HFD-induced NAFLD mice at a dosage of 200 mg/kg BW. These results demonstrated that the methanolic extracts from R. oldhamii leaf have excellent inhibitory activities against fat accumulation and anti-NAFLD activities and thus have great potential as a natural health product.

Improvement in Menopause‐Associated Hepatic Lipid Metabolic Disorders by Herbal Formula HPC03 on Ovariectomized Rats

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Three New Polyynes from Codonopsis pilosula and Their Activities on Lipid Metabolism

“…Cytotoxicity was determined by the MTT assay using previously described method [ 20 ]. HepG2 cells (8000 cells/well) were seeded onto a 96-well plate and incubated for 24 h to allow cell adherence.…”

Chrysanthemum�indicum L. ethanol extract reduces high‑fat diet‑induced obesity in mice

“…Recent study reported that quercitrin containing extract of Chrysobalanusicoco leaves inhibited fat accumulation in HFD-fed mice (36). Also, quercitrin isolated from Rhododendron oldhamii leaf extract improves fatty liver syndrome via increase of lipid oxidation and decrease of lipogenesis (37). Thus, quercitrin may be one of the compounds that contribute to the anti-obesity effect of CIEE.…”