Effect and mechanism of total alkaloids of strychnine on papain induced rabbit knee osteoarthritis

Abstract

Objective: To examine the effect and mechanism of Strychnine total alkaloids on a model of knee osteoarthritis. Methods: New Zealand rabbits were randomly divided into normal group, model group, total alkaloid high/medium/low dose groups and a sodium hyaluronate group. Except for the normal control group, all other groups were injected with papain in the joint cavity to establish osteoarthritis. After 8 weeks of modeling, a high, medium and low dose of Strychnine total alkaline was given by injection in the joint cavity, 0.3 ml, 0.2 ml, and 0.1 ml respectively. At this time an intra-articular injection of 0.2 ml sodium hyaluronate was also given to the hyaluronate group. The injection of Strychnine total alkaline was continually administered, twice a week for 5 weeks. All animals were harvested for analysis one week after the final dose. Pathological changes of articular cartilage were observed and evaluated by Mankin's score. Total blood viscosity (low shear, middle shear, high shear) and plasma viscosity were measured by hemorheometer. The levels of IL-1 and IL-6, SOD, LPO, NO, and TNF in the synovial fluid and PYD in urine were additionally measured by enzyme-linked immunosorbent assay (ELISA). Main findings: Compared with the osteoarthritis controls, the cartilage injury was significantly improved in the total alkaloid group. Mankin's score was significantly decreased (P<0.05), and the blood viscosity and plasma viscosity of low, middle and high shear rates was decreased (P<0.05). Finally, IL-1, IL-6, LPO, NO and TNF in synovial fluid were decreased while SOD content increased (P<0.05). Conclusion: These results indicate that Strychnine total alkaloids have reparative effects on cartilage injury during osteoarthritis. The mechanisms may at least partially be related to the inhibition of inflammatory factors, the regulation of free radicals and the overall improvement of cartilage metabolism.