It was to investigate the neuroprotective mechanism of tanshinone after cerebral infarction via the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant reaction element (ARE) signaling pathway. Forty specific pathogen-free (SPF) Sprague Dawley (SD) rats were selected, all of which were male, approximately seven weeks old, weighing 250 ± 25 g. They were randomly divided into a model group, a non-model operation group, a positive control group, and an experimental group with ten SD rats in each group. The model of cerebral infarction in rats was established by the wire occlusion method. The model group and non-model operation group (control group) were injected with normal saline daily, the negative control group was injected with Keap1 gene inhibitor daily, and the experimental group was injected with tanshinone IIA (10 mg·kg-1·d-1) daily. Animal behavior analysis was performed on the 7th day after the operation, and pathology and the neuroprotective effects of tanshinone IIA on cells were assessed, including cell proliferation, autophagy, oxidative damage, and mitochondrial membrane permeability. The neuroprotective mechanism based on the Keap1-Nrf2/ARE pathway was explored and analyzed. Compared with the model group, the number of Keap1 proteins in the experimental group and the control group was substantially reduced (P < 0.05), and the experimental group was substantially different from the model group (P < 0.01). The protein expression of Nrf2, HO-1, and NQO1 increased substantially (P < 0.05), and the experimental group was substantially different from the model group (P < 0.01). In summary, tanshinone IIA promoted the proliferation of nerve cells, inhibited the production of cellular reactive oxygen species, inhibited the change in mitochondrial membrane potential, and activated the Keap1-Nrf2/ARE signaling pathway. It also induced and regulated the upregulation of downstream NQO1, HO-1, etc. and protected cells from cerebral infarction.
Keywords: Keap1-Nrf2/are pathway; cerebral infarction; neuroprotection; tanshinone IIA.