ABSTRACT
ObjectiveTo observe the effect of Sanhuang Tangshenkang on the Wnt/β-catenin signaling pathway in the bone tissue of diabetic rats. MethodA high-sugar and high-fat diet was administered for 4 weeks， along with intraperitoneal injection of freshly prepared 2% streptozotocin （pH 4.5） at 30 mg·kg-1 body weight to induce a diabetes model in rats. The rats with diabetes were randomly divided into model group， low- and high-dose Sanhuang Tangshenkang groups （12.8， 38.4 g·kg-1）， and Gushukang group （1.8 g·kg-1） according to the blood glucose level. Rats of the same age were fed on a regular diet and assigned to the control group. After 12 weeks of respective treatments with drugs or physiological saline， the fasting blood glucose （FBG） levels of the rats were measured using an automated biochemical analyzer. Enzyme-linked immunosorbent assay （ELISA） was used to detect fasting serum insulin （FINS）， bone-specific alkaline phosphatase （BALP）， and tartrate-resistant acid phosphatase （TRAP） levels. Micro-computed tomography （Micro-CT） was used to scan the femurs of rats to observe bone tissue microstructure and measure bone mineral density （BMD）. Hematoxylin-eosin （HE） staining and safranin O/fast green staining were performed to observe pathological changes in the femoral bone tissue. Immunohistochemistry （IHC） and Western blot were used to detect the expression of Wnt3a， low-density lipoprotein receptor-related protein 5 （LRP-5）， and β-catenin proteins. ResultCompared with the control group， the model group showed a significant increase in FBG， FINS， and TRAP levels （P<0.01）， a significant decrease in BALP level （P<0.01）， a significant decrease in BMD （P<0.01）， and disorganized， elongated， and sparse bone trabecular structures with fractures and increased lipid droplets. Additionally， the expression of Wnt3a， LRP-5， and β-catenin proteins decreased （P<0.05， P<0.01）. Compared with the model group， the low- and high-dose Sanhuang Tangshenkang groups showed a reduction in FBG and an increase in BALP （P<0.05）. The low-dose Sanhuang Tangshenkang group also exhibited a decrease in FINS （P<0.05）. All treatment groups showed a significant decrease in TRAP （P<0.01）， varying degrees of improvement in BMD （P<0.05， P<0.01））， increased and denser bone trabeculae with more regular arrangements and reduced lipid droplets， and improved bone microstructure morphology. The average optical density values of Wnt3a， LRP-5， and β-catenin proteins were significantly increased in all drug-treated groups （P<0.05， P<0.01）， and the expression of Wnt3a， LRP-5， and β-catenin proteins was elevated （P<0.05， P<0.01）. ConclusionSanhuang Tangshenkang may regulate the imbalance of the Wnt/β-catenin signaling pathway by increasing the expression of Wnt3a， LRP-5， and β-catenin proteins in bone tissue， which may promote bone formation， reduce bone resorption， and lower blood glucose levels， thereby achieving the effect of preventing and treating diabetic osteoporosis.