Evaluation of Neuroprotective Effect of Hibiscus sabdariffa   Linn. Aqueous Extract Against Ischaemic-Reperfusion Insult by Bilateral Common Carotid Artery Occlusion in Adult Male Rats

Summary: Ischaemic brain injury continues to be devastating, causing social, medical and relationship disruption. Oxidative damage has been reported to be one of the mechanisms for brain damage following ischaemic stroke. The antioxidant activity of Hibiscus sabdariffa L. was investigated for a possible protective effect against ischaemia-induced brain damage in rats. Adult male Wistar rats (n=35) were divided into five groups of 7 rats per group. Group 1 served as control was given tap water; Group 2: 500 mg/kg daily of Hibiscus sabdariffa L. extract (HSE); Group 3: bilateral common carotid artery occlusion (BCCAO) for 30 minutes followed by reperfusion for 24 hours; Group 4: 500 mg/kg (HSE) before BCCAO; Group 5: 500 mg/kg vitamin E before BCCAO. All administrations were oral and lasted 3 weeks. Behavioural studies namely: transitions, rearings, groomings and forelimb grip strength were carried out. Rats were thereafter euthanized and biochemical [malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT)], histological and morphological investigations were carried out on rat whole brain. Animals pretreated with HSE showed a significant (p<0.05) reduction in their body weight compared to the control group. BCCAO produced a significant (p<0.05) reduction in GSH, SOD and CAT while elevating MDA non-significantly. The HSE and Vitamin E pretreatment ameliorated these biochemical alterations and also attenuated reactive changes in cortical neurons. BCCAO treatment increased grooming and forelimb strength which both HSE and vitamin E pretreatment reversed. The results suggest that H. sabdariffa L and vitamin E were protective in acute cerebral ischaemia induced by bilateral common carotid artery occlusion in adult male rats.