Abstract: Objective:To optimize the extraction processing of deer sinew, and study its effects on the proliferation of MH7A cells and the secretion of inflammatory factors. Methods:Single factor extraction was carried out with solid-liquid ratio, extraction temperature, time as independent variables and deer sinew contents as dependent variables. And Box-Behnken experiment design was used to obtain the optimum extraction processing of deer sinew.MH7A cells were induced by 60 ng/mL tumor necrosis factor-α (TNF-α). MTT assay was used to determine the effects of different concentrations of deer sinew protein (25, 50, 100, 200 ug/mL) on the proliferation of MH7A cells, and ELLSA was used to determine the contents of NO, IL-6 and TNF-α in cell supernatant. Results:The optimum extraction conditions of deer sinew protein were 88℃, 8.6 h, 1:21 g/mL, and the protein content of deer sinew was 12.53%.In vitro anti-inflammatory experiments showed that different concentrations (25, 50, 100, 200 ug/mL) of deer sinew could inhibit the proliferation of MH7A cells and the release of NO, IL-6 and TNF-α (P<0.05).The release of NO, IL-6 and TNF-α in the model group were 4.07, 21.95, 16.31 pg/mL, and deer sinew could inhibit the proliferation of MH7A cells at 100 μg/mL, the release of inflammatory factors in the deer sinew group were 1.60, 13.60, 7.29 pg/mL, respectively. Conclusion:Deer sinew protein plays an anti-rheumatoid arthritis role by inhibiting the proliferation of MH7A cells induced by TNF-α and reducing the release of inflammatory factors NO, IL-6 and TNF-α.This study would lay a foundation for the extraction of deer sinew protein, provide a reference for further study of the preparation process of deer sinew protein, and prove that deer sinew protein have good anti rheumatoid joint activity.