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.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate effects of electro-acupuncture (EA) on Du Meridian on the water channel aquaporin-4 (AQP-4) expression and hind limbs function recovery in experimental spinal cord injured rats.</p><p><b>METHODS</b>One hundred and fifty SD rats were divided into the normal group, the model group and the EA group, with 50 rats in each group, modified Allen method was used to establish spinal cord injury model in the model and EA group. Rats in the EA group was EA on Dazhui and Ming men acupoints after modelling successfully. At the 1st, 3rd, 7th, 14th and 21th day after injury, the hind limbs function of rats was evaluated by BBB scales respectively, and the AQP-4 expression in spinal cord tissue was determined by immunohistochemistry technique and quantity analysed with image analyzer.</p><p><b>RESULTS</b>At the 1st day after spinal cord injury, the AQP-4 expression was significantly increased in gray matter and white matter of spinal cord in the model group and the EA group, which reached the peak at the 3rd day, but showed significant difference between the two groups (P < 0.05), and the difference at the 7th, 14th and 21th day became more significant (P < 0.01).</p><p><b>CONCLUSION</b>EA on Du Meridian can down-regulate AQP-4 expression after spinal cord injury, inhibit spinal cord edema for alleviating secondary spinal cord lesion, so as to protect the residual normal spinal cord tissues and promote the rebuilding of nervous tissues.</p>