ABSTRACT

Rooibos is a herbal tea prepared from the plant Aspalathus linearis. Aside from being a herbal tea, it has also been used to make skin creams, soap, and cosmetics. This study aims to assess the neuroprotective potential of Aspalathus linearis in mercury chloride-induced cerebral toxicityin adult Wistar ratsForty-two rats were equally divided into seven groups (A-G). Group A served as the control group. Group B served as the toxin group and received 4mg/kg of Mercury chloride only. Group C and D were pre-treated with 250mg/kg and 500mg/kg of Aspalathus linearis and induced with 4mg/kg of Mercury chloride respectively. Group E was treated with 500mg/kg of Aspalathus linearis only. Group F was pre-treated with 500mg/kg of Vitamin E and induced with 4mg/kg of Mercury chloride. Group G received 500mg/kg of Vitamin E only. All forty-two animals were sacrificed on the twenty-eight day. A neurobehavioral test was done to ascertain the response of the rats used in the experiment. Y-maze test showed no significant change (P<0.05) in the spontaneous reaction time in rats induced with Mercury chloride when compared to rats in the control group. Oxidative stress analysis showed that the level of MDA in the cerebrum significantly increased (P<0.05) in rats that were induced with Mercury chloride when compared with rats in the control group. A significant decrease (P<0.05) was observed in the pre-treated group of 250mg/kg of Aspalathus linearis, 500mg/kg of Aspalathus linea,ris, and 500mg/kg of Vitamin E when compared to the toxin-induced group. The level of GPx significantly reduced (P<0.05) for rats in the toxin group that received 4mg/kg of Mercury chloride when compared to the control group. A significant increase (P<0.05) was observed in the pre-treated group that received 250mg/kg of Aspalathus linearis and induced with Mercury chloride and the rats in the pre-treated group that received 500mg/kg of Vitamin E and induced with 4mg/kg of Mercury chloride when compared with the 4kg/kg Mercury chloride toxin-induced group. Haematoxylin and Eosin staining revealed necrosis and infiltration of inflammatory cells in the cerebrum for rats that were induced with 4mg/kg of Mercury chloride only when compared with the control group. When pre-treated with Aspalathus linearis and Vitamin E, these effects were not observed. It can be concluded based on this research that Aspalathus linearis protects the cerebrum against Mercchloride-induceduced toxicity.