Neuroprotective effects of polyhydroxy pregnane glycoside isolated from Wattakaka volubilis (L.f.) Stapf. after middle cerebral artery occlusion and reperfusion in rats.

Wattakaka volubilis (L.f) (Stapf.) is well known for its rich steroid pregnane contents and this plant is known for its potential use as alternative biological activities. However, little is known about its neuroprotective effect in ischemia-reperfusion (I/R)-induced cerebral injury. Hence, the present study was carried out to investigate the effect of W. volubilis(L.f) (Stapf.) sapogenin glycosides mixture (WVSM) and polyhydroxy pregnane glycoside (PPG) isolated from it on neuroprotection and the potential mechanisms in the rat I/R model induced by middle cerebral artery occlusion (MCAO). The rats were pretreated with WVSM (50 mg/kg) and PPG (5 mg/kg and 10 mg/kg) (p.o.) once a day for 5 days before MCAO. Neurological deficit score (NDS), rotarod performance, brain water content, 2,3,5-triphenyltetrazolium chloride (TTC) staining and indices of oxidative stress [superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) and nitric oxide synthase (NOS)] were measured at 24 h after ischemia. The results indicated that pretreatment with WVSM and PPG (10 mg/kg) significantly diminished the volume of infarction and brain water content, and improved NDS. Moreover, WVSM and PPG (10 mg/kg) markedly reversed the level of MDA, NO, NOS and SOD to their normal state in serum or cerebral ischemic section. These findings demonstrate that WVSM and PPG (10 mg/kg) exhibit neuroprotective effect through its anti-oxidative action in MCAO rats.