Abstract: PURPOSE: To investigate the effect of different concentrations of oyster protein peptide on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). METHODS: BMSCs of the third generation from rats with stable subculture ability were selected, and the cell viability was detected by MTT kit at different concentrations of 0, 10, 20 and 50 mg/L oyster protein peptide for 24 hours, 3 days and 7 days. BMSCs were divided into two groups: cultured with DMEM or ODM. According to the different concentrations of oyster protein peptide, the experimental groups were divided into four subgroups, which were 0, 10, 20 and 50 mg/L, respectively. The effects of different concentrations of oyster protein peptide on the early osteogenic differentiation of BMSCs were evaluated by ALP staining and ALP semi-quantitative detection. Alizarin red staining was used to detect the effect of different concentrations of oyster protein peptide on the osteogenesis and mineralization of BMSCs after 21 days of treatment. RT-PCR was used to defect the expression of bone formation-related genes. SPSS 20.0 software package was used to analyze the data. RESULTS: The results of MTT showed that cell activity was vigorous and there was no obvious abnormality after intervention with different concentrations of drugs, but the number of cell death increased when the concentration of oyster protein peptide was 50 mg/L. The results of ALP semi-quantitative analysis showed that ALP activity of DMEM and ODM group was significantly higher than that of the control group (P<0.05) on the 10th day of differentiation induction, but there was no significant difference between 50 mg/L group and the control group. Alizarin red semi-quantitative analysis showed that the A value of 20 mg/L in ODM group was significantly higher than that of the control group(P<0.05). The expression of RUNX-2 and OCN in 10 mg/L and 20 mg/L groups were significantly higher than that in control goup and 50 mg/L group(P<0.05). CONCLUSIONS: Oyster protein peptide with a concentration higher than 50 mg/L can significantly inhibit osteogenic differentiation of BMSCs, while oyster protein peptide with a low concentration, especially oyster protein peptide with a concentration of 20 mg/L, can promote osteogenic differentiation and cell growth of BMSCs.

Key words: Oyster protein peptide, Stem cell, Osteogenic differentiation, Traditional Chinese medicine