Cerevisterol from Ophiocordyceps sinensis fruiting bodies against liver fibrosis.

OBJECTIVE

Liver fibrosis is a critical pathological process to irreversible cirrhosis. The valued Ophiocordyceps sinensis (Berk.) G.H. Sung, J.M. Sung, Hywel-Jones and Spatafora (Ophiocordycipitaceae, Hypocreales) fungus exhibits remarkable hepatoprotective effects, especially anti-inflammation. However, detailed metabolites with anti-inflammation activity need to be explored from this fungus. This study investigates the anti-liver fibrosis effect of cerevisterol extracted from O. sinensis fruiting bodies on TGF-β1-induced LX-2 cells (a human hepatic stellate cell line) and the underlying potential mechanisms.

METHODS

The metabolites were extracted and purified by petroleum ether, ethanol reflux extraction and chromatographic separation technology. Their structures were identified based on extensive NMR and MS data. TGF-β1-induced LX-2 cells were employed to study the anti-inflammation activity of the isolated cerevisterol. The mRNA expression of Smad3, Smad4, and Collagen I in the cells was verified by qRT-PCR and Smad3 and Smad4 proteins by Western blot.

RESULTS

Cerevisterol, adenosine, uridine, ergosterol, 2-piperidone, L-tryptophan and (24S)-ergost-7(8)-en-3β,5α,6β-triol were obtained. In the TGF-β1-induced fibrosis model, cerevisterol (10 μM) and a commercial anti-liver fibrosis drug containing Chinese cordyceps (75 ng/mL) as positive control significantly suppressed cell proliferation at 72 and 96 hours. qRT-PCR analysis demonstrated that cerevisterol downregulated mRNA expression of Smad3, Smad4, and Collagen I. Western blot results confirmed reduced protein levels of Smad3 and Smad4 in the cerevisterol-treated cells.

DISCUSSION: Cerevisterol from O. sinensis fungus exerts anti-liver fibrosis effects by inhibiting hepatic stellate cell activation and proliferation, and by downregulating TGF-β/Smad3 signaling pathway, thereby reducing excessive extracellular matrix-related gene and protein expression.