Effect of licochalcone A on osteoarthritis in rats and its relationship with p38-MAPK inflammatory signaling pathway / 中国基层医药

ABSTRACT

Objective:To investigate the effect of licochalcone A on osteoarthritis in rats and its relationship with p38-MAPK inflammatory signaling pathway.Methods:A total of 160 male Wistar rats were randomly divided into blank non-intervention, blank intervention, arthritis non- intervention and arthritis intervention groups with 40 rats in each group. Rats in the arthritis groups were subjected to unilateral anterior cruciate ligament transection, while rats in the blank groups were only subjected to skin incision and suture. Rats in the intervention groups were treated by intra-articular injection of 1 mL 10 μmol/L licochalcone A for 8 successive weeks. Eight weeks later, the cartilage of rats in each group was stained with safranin, and osteoarthritis soft tissue was scored according to Osteoarthritis Research Society International guideline under the optical microscope. The cartilage was cultured in low glucose cell culture medium supplemented with 5% fetal bovine serum for 48 hours. The contents of nitric oxide, prostaglandin E 2, sulfated glycosaminoglycan and collagen II in the medium were determined by the chemiluminescence reaction method. The expression levels of p38, phosphorylated p38 (p-p38) and matrix metalloproteinase in cartilage tissue were detected by western blot assay. Results:The progress of osteoarthritis in rats treated with licochalcone A was slow. The Osteoarthritis Research Society International score in the arthritis intervention group was significantly lower than that in the arthritis non-intervention group [(3.8 ± 1.7) points vs. (9.7 ± 1.2) points, P = 0.0064]. The contents of nitric oxide, prostaglandin E 2, sulfated glycosaminoglycan, and collagen II in the arthritis intervention group were (77.84 ± 17.65) μmol/mg and (6.78 ± 1.76) ng/mg, (89.78 ± 9.76) μg/mg, and (1.78 ± 0.76) μg/mg, respectively, which were significantly lower than those in the arthritis non-intervention group [(107.56 ± 18.74) μmol/mg, (10.756 ± 1.87) ng/mg, (125.75 ± 8.87) μg/mg, (3.76 ± 0.88) μg/mg, (NO P = 0.002; PGE 2 P < 0.001; sGAG P < 0.001; Collagen II P < 0.001). Western blot assay results revealed that the relative expression of p38, p-p38, p-p38 to total p38 ratio, matrix metalloproteinase in the arthritis intervention group were (3 454 ± 421), (2 072 ± 175), (0.65 ± 0.14 )and (1 776 ± 765), respectively, which were significantly lower than those in the arthritis non-intervention group (5 322 ± 323), (4 257 ± 184), (0.89 ± 0.11), (3 865 ± 874)( p38 P < 0.001; p-p38 P < 0.001; p-p38/p38 P = 0.002; MMP P = 0.001). Conclusion:Licochalcone A can delay the progression of osteoarthritis in rats with osteoarthritis through inhibiting inflammatory reaction and cartilage matrix degradation, and p38-MAPK signaling pathway may be involved in the regulation process.