Effect of Tibetan Medicine Berberis Cortex on Expressions of PKC-β, VEGF, HIF-1α in Retina of Diabetic Rats / 世界科学技术-中医药现代化

ABSTRACT

This study was aimed to investigate the effects of extract from Tibetan medicine Berberis Cortex (TMBC) on expressions of protein kinase C (PKC-β), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF-1α) in the retina of diabetic rats. Diabetic rats were established by one time intraperitoneal injection of strepto-zocin (STZ). Rats were randomly divided into the model group, low-dose TMBC group, medium-dose TMBC group, high-dose TMBC group, metformin group, calcium dobesilate group, berberine group and the normal control group. Intragastric administration was given. The medication amounts of TMBC in the low-dose, medium-dose and high-dose group were 5, 10, and 20 times to the adult medication dose. In the metformin group and the berberine group, 10 times of the adult medication dose were given. Distilled water was given in the model group and the normal con-trol group. After 6-week intragastric administration, all experimental rats were sacrificed. The expressions of PKC-β, VEGF and HIF-1α were examined by real-time fluorescence quantitative PCR assay and western blot. HIF-1α ex-pression was detected by immunohistochemistry. The results showed that compared with the normal control group, the mRNA and protein expression of PKC-β, VEGF and HIF-1α increased obviously in the retina of diabetic rats ( P<0.01). Compared with the model group, the mRNA expression of PKC-β, VEGF and HIF-1α in the high-dose and medium-dose TMBC group reduced obviously (P< 0.01). The protein expression levels of PKC-β, VEGF and HIF-1α were also obviously reduced (P< 0.05). The expressions of PKC-β, VEGF and HIF-1α in the low-dose TMBC group were obviously reduced (P < 0.05). It was concluded that TMBC can depress the expressions of HIF-1α, PKC-β and VEGF in the retina of diabetic rats, which can be served as a protective effect to prevent progress of di-abetic retinopathy.