Anti-inflammatory effects of powdered product of Bu Yang Huan Wu decoction: Possible role in protecting against Transient Focal Cerebral Ischemia

Abstract

Bu Yang Huan Wu decoction (BYHW) is a traditional Chinese medicine (TCM) that consists of several herbs and has been used in patients with ischemic stroke for centuries. Although powdered formula of BYHW has widely been prescribed in clinic nowadays, evidence-based effectiveness and mechanism of action of BYHW powdered product in stroke remain to be characterized. Adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 90 min followed by reperfusion for 24 h (ischemia/reperfusion; I/R) or sham surgery. After I/R, the rats were then given low dose (0.5 g/kg) and high dose (2.5 g/kg) of BYHW or vehicle by oral gavage twice a day for seven consecutive days. The results showed that I/R induced obvious cerebral infarction and neurobehavioral defects, in parallel with histological aberrations and extensive signaling of proinflammatory cytokines, including tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), in the stroke model. Post-I/R treatment with BYHW powdered product significantly reduced the infarct area and ameliorated neurofunctional defects in a dose-dependent manner. The dose dependence was associated with TNF-α downregulation and interleukin-10 (IL-10) induction. In summary, the present findings demonstrated that BYHW powdered product exhibited therapeutic efficacy for experimental stroke and a higher dose treatment may strengthen the effectiveness via inflammatory modulation.

Keywords: Bu Yang Huan Wu decoction; Ischemic/reperfusion; Stroke; inflammation.

Figure 1

Powdered product of BYHW ameliorates I/R-induced infarct damage in the cerebral cortex of rats. (a) Representative 2,3,5-triphenyltetrazolium chloride (TTC)-stained coronal cortical sections from sham-operated rats and MCAO/reperfusion (I/R) rats receiving vehicle, low-dose or high-dose powdered BYHW. (b) Higher magnification images of the fourth sections of all groups are presented. (c) The area of infarcted brain tissue at 7 days after sham operation or I/R was estimated and expressed as a percentage of the whole section area. Data were presented as mean ± SD (n = 3 in each group). ***, P < 0.001 compared with sham-operated group; +++, P < 0.001 compared with I/R group; ###, P < 0.001 between groups treating with low-dose and high-dose powdered BYHW.

Figure 2

Powdered product of BYHW ameliorates I/R-induced histological alterations in the cerebral cortex of rats. (a) Representative results of Hematoxylin and eosin (HE) staining in cortical sections from sham-operated rats and MCAO/reperfusion (I/R) rats receiving vehicle, low-dose or high-dose powdered BYHW. (b) High magnification of HE staining. Scale bars: 200 µm in (a); 50 µm in (b).

Figure 3

Powdered product of BYHW ameliorates I/R-induced neurobehavioral impairment in rats. (a and b) Corner test (a) and modified neurological severity scores (mNSS) (b) of sham-operated rats and MCAO/reperfusion (I/R) rats receiving vehicle, low-dose or high-dose powdered BYHW at 1, 7, and 14 days after sham operation and I/R. Data were presented as mean ± SD (n = 3 in each group). ***, P < 0.001 compared with sham-operated group; ++, P < 0.01 and +++, P < 0.001 compared with I/R group; #, P < 0.05 and ###, P < 0.001 between groups treating with low-dose and high-dose powdered BYHW.

Figure 4

Powdered product of BYHW reduces the expression of TNF-α and IL-6 in the cerebral cortex of MCAO/reperfusion (I/R) rats. (a and b) Representative results of immunohistochemical staining (IHC) for TNF-α (a) and IL-6 (b) in cortical sections from sham-operated rats and I/R rats receiving vehicle, low-dose or high-dose powdered BYHW. Scale bars: 100 µm.

Figure 5

Powdered product of BYHW reduces the protein levels of TNF-α and IL-6 in the brain of MCAO/reperfusion (I/R) rats. (a and b) The protein levels of TNF-α (a) and IL-6 (b), as measured by ELISA, in the brains obtained from sham-operated rats and I/R rats receiving vehicle, low-dose or high-dose powdered BYHW at 7 days after sham operation or I/R. Data were presented as mean ± SD (n = 3 in each group). ***, P < 0.001 compared with sham-operated group; +++, P < 0.001 compared with I/R group; #, P < 0.05 between groups treating with low-dose and high-dose powdered BYHW.

Figure 6

Powdered product of BYHW increases the protein levels of TGF-β and IL-10 in the brain of MCAO/reperfusion (I/R) rats. (a and b) The protein levels of TGF-β (a) and IL-10 (b), as measured by ELISA, in the brains obtained from sham-operated rats and I/R rats receiving vehicle, low-dose or high-dose powdered BYHW at 7 days after sham operation or I/R. Data were presented as mean ± SD (n = 3 in each group). ++, P < 0.01 and +++, P < 0.001 compared with I/R group; ##, P < 0.01 between groups treating with low-dose and high-dose powdered BYHW.

Figure 7

Powdered product of BYHW reduces lipid peroxidation in the cerebral cortex of MCAO/reperfusion (I/R) rats. (a and b) The level of malondialdehyde (MDA), as measured by ELISA, in the brains obtained from sham-operated rats and I/R rats receiving vehicle, low-dose or high-dose powdered BYHW at 7 days after sham operation or I/R. Data were presented as mean ± SD (n = 3 in each group). ***, P < 0.001 compared with sham-operated group; +++, P < 0.001 compared with I/R group.