Salvianolic acid B promotes the survival of abdominal island flap after ischemia-reperfusion injury in rats

Abstract

Objective To explore the therapeutic effect of salvianolic acid B (Sal B) on rat abdominal island flap after ischemia-reperfusion injury, and to explore the related mechanisms. Methods Fifty-four male Sprague-Dawley rats were randomly divided into 3 groups and rat lower abdomen island flap models were established: ①Sham-operated group (Sham group): non-blocking blood vessels, intraperitoneal injection of equal volume of saline as Sal B group; ②Model group: blocking blood vessels for 8 h, intraperitoneal injection of the same volume of saline as Sal B group; ③salvianolic acid B group (Sal B group): blocking blood vessels for 8 h, intraperitoneal injection of 40 mg/Kg of Sal B per day. Seven days after continuous drug administration, the survival rate of the flaps in each group was evaluated, and then the animals from each group were sacrificed for the specimens which were used for the following tests: HE staining was performed to evaluate the microvessel density (MVD), and immunohistochemistry was used to detect the level of vascular endothelial growth factor (VEGF) and superoxide dismutase 1 (SOD1). The contents of superoxide dismutase SOD and malondialdehyde (MDA) in flap tissue were tested using the corresponding kit. Results Seven days after flap operation, the survival rate of Sal B group flap[(65.62±13.20)%] was significantly higher than that of the model group, while HE staining showed an increase in MVD in Sal B group [(28.27±3.19)/mm2 and (15.79±6.12)/mm2, respectively]. The differences were statistically significant (P<0.05) . Moreover, immunohistochemistry demonstrated that the expression of VEGF and SOD1 obviously increased in Sal B group, and the content of SOD increased significantly. In addition, the expression of MDA decreased after Sal B treatment. The differences were statistically significant (P<0.05) . Conclusion Sal B is able to increase the expression of VEGF and SOD in the rat abdominal island flaps after ischemia-reperfusion injury, to reduce the content of MDA, and then to promote survival rate of rat abdominal island flap. Key words: Salvianolic acid B; Island flap; Angiogenesis; Oxidative stress; Rat