Abstract:Objective To investigate the protective effect of Qihong Tongluo Granule against cerebral ischemia/reperfusion injury in rats and its preliminary mechanism of action. Methods Sprague- Dawley rats were randomly divided into sham- operation group, model group, nimodipine group, and high- , middle- , and low- dose (10.8,5.4, and 2.7 g/kg) Qihong Tongluo Granule groups. The suture method was used to establish a rat model of focal cerebral ischemia/reperfusion injury. The rats were administered once a day by gavage for 3 consecutive days before surgery and 2 consecutive days after surgery. At 72 hours after surgery, the Longa method was used to determine neurological deficit score; TTC staining was used to measure cerebral infarct volume; HE staining was used to observe the pathological changes of brain tissue; colorimetry was used to measure the content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH- Px) in brain tissue; Western blot was used to measure the protein expression levels of nuclear factor erythroid 2- related factor 2 (Nrf2) and heme oxygenase- 1 (HO- 1) in brain tissue. Results Compared with the model group, the high- , middle- , and low- dose Qihong Tongluo Granule groups had a significant reduction in cerebral infarct volume (P<0.05); the high- and middle- dose Qihong Tongluo Granule groups had significantly alleviated symptoms of neurobehavioral disturbance (P<0.05) and pathological changes of brain tissue; the high- , middle- , and low- dose Qihong Tongluo Granule groups had a significant reduction in the content of MDA and significant increases in the activities of SOD and GSH- Px in brain tissue (P<0.05); the high- and middle- dose Qihong Tongluo Granule groups had significant increases in the protein expression levels of Nrf2 and HO- 1 in brain tissue (P<0.05). Conclusion Qihong Tongluo Granule exerts a good protective effect against cerebral ischemia/reperfusion injury in rats, possibly by activating the Nrf2/HO- 1 signaling pathway, inhibiting oxidative stress response, and thus producing an antioxidant effect.