Buyang-Huanwu decoction combined with enriched environment on the abnormal activation of astrocytes and the expression of angiogenic factors in rats with cerebral ischemia

Abstract

Objective To observe the effects of Buyang-Huanwu decoction (BYHWD) combined with enriched environment (EE) on the abnormal activation of astrocytes and expression of angiogenic factors in rats with cerebral ischemia. Methods The rat model of permanent middle cerebral artery occlusion (pMCAO) was established by using suture method. Male SD rats were randomly divided into sham, model, EE, BYHWD and BYHWD+EE group. Rats in the BYHWD and BYHWD+EE groups were intragastrically adminstratered with BYHWD (16.1g/kg) 24h after MCAO and once daily for consecutive 15 days. Accordingly, rats in the sham, model, and EE groups were adminstratered with the sam volume normal saline. Rats treated with EE and BYHWD+EE were housed in the enriched environment 12 h every day. The EE, BYHWD and BYHWD+EE group rats were given relative treatment continuously for 15 days. Beam walking test was performed to examine the motor function of rats. Next, the HE staining was conducted to detect the pathological alterations of the brain. Immunohistochemical staining with DARPP-32 and GFAP were applied to respectively observe the changes of multiple spinous neurons and activation of astrocytes in the striatum. Subsequently, the mRNA expressions of angiogenic factors including VEGF/VEGFR2 and Ang1/Ang2 were detected by RT-PCR. Results The rats treated with BYHWD+EE revealed markedly elevated beam walking scores on the 7th and 15th day after MCAO compared with model group (P<0.01). Compared with the model, BYHWD+EE treatment significantly increased the number of neurons (31.08 ± 8.06 vs. 19.00 ± 9.12, P<0.01), elevated the number of DARPP-32-positive cells (975.3 ± 589.68 vs. 271.25 ± 164.98) and integral optical density (18 621.87 ± 6 996.64 vs. 4 071.60 ± 2477.27) of DARPP-32 (P<0.01), suppressed the expression of GFAP (6 094.07 ± 3 211.74 vs. 10 002.91 ± 8 430.34, P<0.01) and up-regulated the mRNA levels of VEGF (1.59 ± 0.80 vs. 0.77 ± 0.33), VEGFR2 (1.58 ± 0.88 vs. 0.70 ± 0.37), Ang1 (1.58 ± 0.52 vs. 0.84 ± 0.13), and Ang2 (1.25 ± 0.25 vs. 0.90 ± 0.22) in the striatum (P<0.05 or P<0.01). Conclusions The Buyang-Huanwu decoction combined with enriched environment exerted synergistic effect on ischemic rats and promoted motor function by inhibiting the excessive activation of astrocytes and improving the expression of angiogenic factors. Key words: Bu Yang Huan Wu Tang; Brain Ischemia; Enriched environment; Astrocyte; Angiogenic; Rats