Effect Of Gastrodin On Bone Tissue Around Implants In Type 2 Diabetic Rats

Objective:To study the effects of gastrodin on blood glucose,oxidative stress,apoptosis and bone formation around implants in type 2 diabetic rats.Methods:40 SD rats aged 5 weeks were divided into control group(n=10)and model group(n=30).The model group was fed with high fat and high sugar diet for 4 weeks and injected with 1%,35 mg/kg streptozocin intraperitoneally.Blood glucose was measured in peripheral blood of rat after 3 days,and random blood glucose>16.7 mmol/L was used as the standard of successful model.Excluding the failed model rats and the dead rats,the remaining rats were divided into diabetic group(n=10)and gastrodin group(n=10).Pure screw titanium implants were placed in the metaphysis of both tibia.Rats in gastrodin group were given gastrodin 13.6 mg/kg/d,while the diabetic group was given the same dose of saline solution.After operation,blood glucose was measured regularly in all rats.After 4,8 weeks,WST-1 and TBA were used to analyze the oxidative stress level in rats.The expression of bone apoptosis protein was analyzed by immunohistochemistry.HE staining and micro-CT scanning were used to analyze the bone tissue around the implants.Results:The blood glucose of rats at different time[control group:(5.75±1.13),(5.60±1.32),(5.90±0.80)and(6.24±1.17)mmol/L;diabetic group:(20.97±2.27),(17.94±3.76),(23.66±2.90)and(21.22±2.67)mmol/L;gastrodin group:(12.98±2.53),(13.64±1.96),(14.58±3.40)and(12.84±2.82)mmol/L]was different between three groups(P<0.05).The MDA concentration in gastrodin group[(5.21±1.60)and(3.47±1.17)nmol/ml]was significantly lower than that in diabetic group[(11.42±5.11)and(7.31±1.37)nmol/ml]at4 and 8 weeks postoperativel(P<0.05),while the SOD activity in gastrodin group[(42.89±6.00)and(53.12±9.73)U/ml]was significantly higher than that in diabetic group[(27.09±6.11)and(32.08±2.97)U/ml]at 4 and 8 weeks(P<0.05).Immunohistochemistry showed that the bcl-2 expression in gastrodin group(32.68±7.17,45.92±15.32)was significantly higher than that in diabetic group(14.42±4.35,16.43±2.80)at 4 and 8 weeks postoperativel(P<0.05),while the bax expression in gastrodin group(19.14±2.62,19.15±2.47)was significantly lower than that in diabetic group(34.77±1.20,69.27±23.23)at 4 and 8 weeks(P<0.05).Four weeks after surgery,the BV/TV,Conn.D,Tb.N,Tb.Th in gastrodin group[(34.18±2.74)%,(13.80±0.62)1/mm~3,(1.59±0.12)1/mm and(0.72±0.11)mm]were significantly higher than those in diabetic group[(29.44±2.93)%,(11.38±1.01)1/mm~3,(1.30±0.11)1/mm and(0.53±0.09)mm];the Tb.sp in gastrodin group(0.31±0.04)mm was significantly lower than diabetic group(0.39±0.03)mm(P<0.05);Eight weeks after surgery,the BV/TV,Conn.D,Tb.N in gastrodin group[(51.66±4.15)%,(18.24±0.84)1/mm~3,(1.82±0.07)1/mm]was significantly higher than diabetic group[(44.89±4.24)%,(16.73±1.07)1/mm~3](P<0.05);There was no significant difference in Tb.Th and Tb.sp[control group:(1.00±0.14)and(0.29±0.03)mm,diabetic group:(0.85±0.12)and(0.31±0.03)mm,gastrodin group:(0.98±0.24)and(0.31±0.04)mm]in three group(P>0.05).The trabecular structure in gastrodin group was better than that in diabetic group by HE staining.Conclusion:13.6mg/kg/d gastrodin can significantly reduce blood glucose,improve redox state,alleviate apoptosis and promote bone formation around implants in type 2 diabetic rats.