Abstract: PURPOSE: This study aimed at exploring the effect of berberine (C₂₀H₁₈NO₄) on osteogenic differentiation of rat adipose-derived stem cells(ADSCs) and clarifying the related mechanism. METHODS: ADSCs were subjected to 5, 10, 20 μmol/L berberine culture solution. The untreated ADSCs were set as the control group. Cell proliferation activity was determined by MTT method. Alkaline phosphatase (ALP) staining, semi-quantitative assay and alizarin red staining (ARS) were applied to analyze the effect of berberine on osteogenic differentiation of ADSCs. The phosphorylation level of c-Jun amino terminal kinase (JNK) protein was tested by Western blot. Runx2, OCN were tested by Western blot before and after application of JNK pathway inhibitor SP600125. SPSS 22.0 software package was used for statistical analysis. RESULTS: There was no significant difference on cell proliferation activity of ADSCs treated with 5, 10 and 20 μmol/L berberine at 1, 3 and 7 day(P>0.05). ALP staining and ARS staining in groups treated by berberine were significantly darker than those of the control group, and ALP protein secretion in the experimental group was significantly up-regulated (P<0.05). The phosphorylation level of JNK was increased after treated with 10 μmol/L berberine culture medium. The expression of osteogenic related proteins Runx2 and OCN was up-regulated in the experimental group. After inhibition of JNK signaling pathway, the expression of Runx2 and OCN was down-regulated. CONCLUSIONS: Berberine has no effect on cell proliferation of ADSCs, and can up-regulate osteogenic differentiation of ADSCs through activation of JNK signaling pathway.

Key words: Berberine, Adipose-derived stem cells, Osteogenic differentiation, C-Jun amino-terminal kinase signaling pathways