Hibiscus sabdariffa calyx protect against oxidative stress and aluminium chloride-induced neurotoxicity in the brain of experimental rats

We evaluated the antioxidant and neuroprotective potentials of extracts of Hibiscus sabdariffa calyx in Wistar albino male rats injected intraperitoneally with aluminium chloride at a dose of 7 mg/kg/day. Phytochemical screening of H. sabdariffa calyx show that coumarin glycosides and steroid were absent after drying at 50 (o)C. At 30 (o)C, there were significant (p < 0.05) highest amounts of phenols, flavonoids, alkaloids, tannin, and saponin. The extracts showed significantly (p < 0.05) high dose-dependent antioxidant activities. MDA significantly (p < 0.05) increased, while GSH, GPX, SOD, CAT activities significantly (p < 0.05) decreased in the brain of the experimental rats induced with AlCl(3), while treatment with the extracts reversed these effects to a relatively normal level. At doses of 500 and 1000 mg/kg body weight, the extracts of the calyx dried at 30 (o)C exhibited the highest capacity to increase the activities of GSH and GPx. Also, AlCl(3) caused significant increases (p < 0.05) in the percentage inhibition of acetylcholinesterase and butyrylcholinesterase activities, and a significantly (p < 0.05) lower protein levels in the brain of the test rats, while treatment with the extracts, at low and high doses, significantly (p < 0.05) reversed these effects in the rat brain to near normal.H. sabdariffa exhibited a good potential to protect against oxidative stress and neurotoxicity.