Brain plasticity is very sensitive to the environment. Certain neurotrophic factors and neurotransmitter receptors, including brain-derived neurotrophic factor (BDNF), cyclic adenosine monophosphate response element‑binding protein (CREB), stromal cell‑derived factor‑1 (SDF‑1) and its specific receptor, C-X-C motif chemokine receptor 4 (CXCR4), are important in neurogenesis in adult animals. In the present study, the effects of environmental enrichment (EE) on neurogenesis in the dentate gyrus (DG) and subventricular zone (SVZ), and the protein expression levels of BDNF, CREB, SDF‑1 and CXCR4 were investigated. Adult rats were randomly assigned as controls or underwent EE for 30 days. Subsequently, immunofluorescence staining was used to analyze cell proliferation in the DG and SVZ, and the differentiation and survival of newly‑formed cells in the hippocampus. The protein expression levels of BDNF, phosphorylated CREB (pCREB), protein kinase A catalytic subunit α, SDF‑1 and CXCR4 in the hippocampus were assayed by western blotting. Cognitive function was assessed in a Morris water maze. EE improved cognitive function, and increased the proliferation, differentiation and survival of newly‑formed neurons in the DG of adult rats; however, EE did not activate neurogenesis in the SVZ. Furthermore, EE enhanced the protein expression levels of BDNF, pCREB, SDF-1 and CXCR4 in the hippocampus. These results provide a theoretical basis to explain the beneficial effects of EE on healthy, adult rats.

Myocardial injury caused by the myocardial ischaemia (MI) is still a troublesome condition in the clinic, including apoptosis, oxidative stress and inflammation. Diosmetin inhibits the cellular apoptosis and inflammatory response and enhances antioxidant activity. So, this study was designed to investigate the cardioprotective effects of diosmetin on MI model neonatal rats. Forty Sprague Dawley (SD) rats 7 days old were randomly divided into five groups. Four groups of rats received diosmetin (50, 100, and 200 mg/kg) or vehicle (MI group) after ischaemia. Another group received vehicle without ischaemia to serve as a control group. Rats were pretreated with diosmetin intraperitoneally for 7 days and intoxicated with isoproterenol (ISO, 85 mg/kg, sc) on the last 2 days. The expression of apoptotic molecules, myocardial systolic function index, antioxidant enzymes and myocardial enzyme was analyzed. Compared with the control group, the proliferation marker proteins of Ki67 were increased significantly (P < .05), the MI group significantly increased the cardiac apoptosis, oxidative stress and myocardial enzymes, and weakened myocardial contractility. The levels of p‐P65/P65 were increased significantly (P < .05) with decreased p‐AKT/AKT and p‐Nrf2/Nrf2 (P < .05). Nevertheless, pretreatment with diosmetin reversed these changes, especially high‐dose group. In summary, diosmetin has significant potential as a therapeutic intervention to ameliorate myocardial injury after MI and provides the rationale for further clinical studies.