Qushi Huayu Decoction (祛湿化瘀方) inhibits protein and gene expression of cathepsin B in HepG2 cells induced by free fatty acids / 中国结合医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the experimental efficacy of Qushi Huayu Decoction (祛湿化瘀方,QHD) on, protein and gene expression of cathepsin B (ctsb) in HepG2 cells induced by free fatty acids (FFAs).</p><p><b>METHODS</b>The model of HepG2 steatosis and tumor necrosis factor-α (TNF-α) secretion was induced by long-chain FFAs. HepG2 cells were divided into 4 groups control group (group C), model group (group M), low-dose QHD group (group L) and high-dose QHD group (group H). Long-chain FFAs were added to groups M, L and H. The 10% blank-control serum was added to group C and M, while 5% and 10% QHD-containing sera were added to group L and H, respectively. The levels of serum TNF-α and cellular triglyceride (TG) were detected. Cellular p-IκB and ctsb expression were detected using Western blot and PCR. The expression and distribution of ctsb were observed by immunofluorescence.</p><p><b>RESULTS</b>After incubating with FFA for 24 h, TG deposition in HepG2, TNF-α content in cell supernatant, the protein expression of cellular ctsb and P-IκB, as well as mRNA expression of ctsb increased markedly in group M compared with group C (P<0.05, P<0.01). Compared with group M, TG deposition, the expression of cellular ctsb, P-IκB and ctsb mRNA in groups L and H, as well as TNF-α content in group H, decreased significantly (P<0.05). Cell immunochemical fluorescence studies showed that ctsb was released from lysosomes and distributed in the cytoplasm extensively and diffusedly after being stimulated with FFA. In this study, these above-mentioned changes were inhibited markedly in groups L and H.</p><p><b>CONCLUSION</b>QHD might have a direct inhibitory effect on the ctsb target in the FFA-ctsb-TNFα pathway of hepatic lipotoxicity.</p>