ABSTRACT
BACKGROUND: Preliminary studies have found that ligustrazine can effectively improve the levels of nitric oxide and prostaglandin E2, and alleviate the inflammatory response of osteoarthritis, but the related mechanism remains unclear. OBJECTIVE: To observe the effect of ligustrazine on the expression levels of type Ⅱ collagen fiber α 1, vascular endothelial growth factor (VEGF) mRNA and miR20b in the articular cartilage of knee osteoarthritis model, and to explore the mechanism of ligustrazine for early-stage knee osteoarthritis in rats. METHODS: Healthy male Sprague-Dawley rats were randomized into normal, model, high- and low-dose ligustrazine, and positive control groups. Rats in the latter four groups were used to establish the model of early-stage knee osteoarthritis by intra-articular injection of papain, and were then intragastrically given the administration of normal saline, 100 and 50 mg/kg ligustrazine, and 24 mg/kg celecoxib, respectively. The normal group was given the same volume of normal saline. The treatment in each group lasted for 6 weeks. Then, the rat cartilage was taken, and changes of cartilage tissues were assessed by Mankin scores. Expression levels of type Ⅱ collagen fiber α 1, VEGF mRNA and miR20b in the cartilage were detected by qRT-PCR. RESULTS AND CONCLUSION: The order of Mankin scores was as follows: normal group < high-dose ligustrazine group < positive control group < low-dose ligustrazine group < model group (P < 0.05). The mRNA expression levels of type Ⅱ collagen fiber α 1 and VEGF were the highest in the normal group, followed by the high-dose ligustrazine group, positive control group, low-dose ligustrazine group, and model group (P < 0.05). The expression level of miR20b was significantly up-regulated except the model group, and its order was follows: high-dose ligustrazine group < positive control group < low-dose ligustrazine group. Our results indicate that ligustrazine has a positive effect on early-stage knee osteoarthritis in rats, and the possible mechanisms by which ligustrazine promotes cartilage repair are to up-regulate miR20b expression and to inhibit VEGF mRNA expression.