[Influences of dihydromyricetin on proliferation and apoptosis of chondrocytes in osteoarthritis induced by H2O2 through ROS/p38-MAPK signal pathway].

OBJECTIVE

To analyze the influences of dihydromyricetin on the proliferation and apoptosis of chondrocytes in osteoarthritis induced by hydrogen peroxide (HO) through reactive oxygen species (ROS)/p38 mitogen activated protein kinase (p38-MAPK) pathway.

METHODS

Five C57BL/6J mice were euthanized by cervical dislocation after anesthesia. Chondrocytes were extracted and cultured.After passage, the chondrocytes were divided into control group, H2O2 group (0.8 μmol·L HO), dihydromyricetin low concentration group (0.8 μmol·L HO+20 μmol·L dihydromyricetin), dihydromyricetin high concentration group (0.8 μmol·L HO+80 μmol·L dihydromyricetin), and ROS inhibitor N-acetylcysteine (NAC) group (0.8 μmol·L HO+5 mmol·L NAC). The activity of chondrocytes was measured by methyl thiazolyl tetrazolium (MTT) assay. The apoptosis rate of chondrocytes was measured by Hoechst 33342 method. The level of ROS in chondrocytes was measured by 2, 7-dichlorofluorescein diacetate (DCFH-DA) fluorescence probe.The level of Type II collagen α1 (Col2α1) mRNA was measured by qRT-PCR.And the expression of Col2α1, p-p38-MAPK/p38-MAPK, B cell lymphoma gene-2 (Bcl-2) and Bcl-2 associated X protein (Bax) proteins was detected by Western blot.

RESULTS

The chondrocytes showed swirling fibrous mass, and the expression of COL2α was positive. Compared with the control group, the chondrocyte viability, apoptosis rate, ROS fluorescence intensity, p-p38-MAPK/p38-MAPK, and the expression of Bax protein in H2O22 group increased, the level of Col2α1 mRNA, and the expression of Col2α1 and Bcl-2 proteins decreased (<0.05). Compared with HO group, the chondrocyte viability, apoptosis rate, ROS fluorescence intensity, p-p38-MAPK/p38-MAPK, and the expression of Bax protein in dihydromyricetin low concentration group, dihydromyricetin high concentration group, and NAC group decreased, the level of Col2α1 mRNA, and the expression of Col2α1 and Bcl-2 proteins increased (<0.05).

CONCLUSION

Dihydromyricetin may inhibit chondrocyte apoptosis, inflammatory reaction and oxidative stress by inhibiting ROS/p38-MAPK pathway. Dihydromyricetin may be a potential drug for treating osteoarthritis.