Antioxidant effect of salvianolic acid B on hippocampal CA1 neurons in mice with cerebral ischemia and reperfusion injury

Objetive To investigate the neuroprotective effects and underlying mechanisms of salvianolic acid B (Sal B) extracted from Salvia miltiorrhiza on hippocampal CA1 neurons in mice with cerebral ischemia reperfusion injury. Methods Forty male National Institute of Health (NIH) mice were randomly divided into 4 groups with 10 animals each, including the sham group, the model group, the SalB group (SalB 22.5 mg/kg) and the nimodipine (Nim) group (Nim 1 mg/kg). A mouse model of cerebral ischemia and reperfusion injury was established by bilateral carotid artery occlusion for 30 min followed by 24-h reperfusion. The malondialdehyde (MDA) content, the nitric oxide synthase (NOS) activity, the superoxide dismutase (SOD) activity and total antioxidant capability (T-AOC) of the pallium were determined by biochemistry methods. The morphologic changes and Bcl-2 and Bax protein expression in hippocampal CA1 neurons were observed by using hematoxylineosin staining and immunohistochemistry staining, respectively. Results In the SalB group, the MDA content and the NOS activity of the pallium in cerebral ischemia-reperfusion mice significantly decreased and the SOD activity and the T-AOC significantly increased, as compared with the model group ( P <0.05 or P <0.01). The SalB treatment also rescued neuronal loss ( P <0.01) in the hippocampal CA1 region, strongly promoted Bcl-2 protein expression ( P <0.01) and inhibited Bax protein expression ( P <0.05). Conclusions SalB increases the level of antioxidant substances and decreases free radicals production. Moreover, it also improves Bcl-2 expression and reduces Bax expression. SalB may exert the neuroprotective effect through mitochondria-dependent pathway on hippocampal CA1 neurons in mice with cerebral ischemia and reperfusion injury and suggested that SalB represents a promising candidate for the prevention and treatment of ischemic cerebrovascular disease.