Anti-inflammatory effects of total isoflavones from Pueraria lobata on cerebral ischemia in rats

Abstract

Puerariae radix, the dried root of Pueraria lobata Ohwi, is one of earliest and most important edible crude herbs used for various medical purposes in Oriental medicine. The aim of the present study was to determine the anti-inflammatory effects of Total Isoflavones from P. lobata (TIPL), which contains the unique isoflavone puerarin, in ischemia in vivo models. Oral administration of TIPL (100 mg/kg) reduced the brain infarct volume and attenuated ischemia-induced cyclooxygenase-2 (COX-2) up-regulation at 2 days after middle cerebral artery occlusion (MCAo) in rats. Moreover, TIPL reduced activation of glial fibrillary acid protein (GFAP) and CD11b antibody (OX-42) at 7 days after MCAo in hippocampal CA1 region. These results show that TIPL can protect the brain from ischemic damage after MCAo. Regarding the immunohistochemical study, the effects of TIPL may be attributable to its anti-inflammatory properties by the inhibition of COX-2 expression, astrocyte expression, and microglia.

Figure 1

Preparative HPLC chromatography of Total Isoflavones from P. lobata (TIPL). P: puerarin; D: daidzin; G: genistin.

Figure 2

Anti-inflammatory effects of TIPL against ischemic brain injury. The dark pink area indicates the normal area, whereas the white area indicates the infarct area (A), and percentage of brain infarct area (B). All data are mean ± SD values (n = 10 per group). ** p < 0.01, significantly difference from the control group.

Figure 3

Inhibitory effect of TIPL on COX-2 (A,B,C), OX-42 (D,E,F), and GFAP (G,H,I) expression at 2 or 7 days after ischemia. Sham-operated group (A,D,G), control group (B,E,H), or TIPL 100 mg/kg treated group (C,F,I). Scale bar = 100 μm.