Aluminium-induced Liver and Testicular Damage: Effects of Piliostigma thonningii Methanolic Leaf Extract

Abstract

Background: Aluminium is believed to be non toxic and easily eliminated from the body, a belief which encourages its use in daily life. However, several studies have reported its hepatotoxicity and testicular derangement in animals and humans.
Objective: The protective potential of Piliostigma thonningii (250mg/kg of body weight) methanolic leaf extract on aluminium-induced hepatotoxic and testicular damage in Wister rats was studied.
Methods: Toxicity was induced in experimental animals via oral route using 0.5mg of AlCl₃ per kg of body weight (b.w).  The toxicant and the plant extract were administered with the aid of gastric intubator for a period of 35 days at 24h interval. Thirty male Wistar rats (mean weight, 207±11.01g) were randomly assigned to three groups: a control group treated with 0.5ml of olive oil (vehicle for the extract) and 1ml of saline (vehicle for the toxicant), a second group treated with 0.5mg of AlCl₃ (toxicant) per kg bwt and a third group treated with 0.5mg of AlCl₃ and 250mg of P. thonningii  extract per kg b.w. The serum activities of liver enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) along with sperm function indices (sperm count, sperm motility, live/dead sperm ratio and total morphological abnormalities) were assessed in the animals.
Results: AlCl₃ ingestion caused a decrease in mean gain in body weight, % sperm motility, sperm count and live/dead sperm ratio as well as significant (P<0.05) increase in absolute weight of the liver, total sperm abnormalities, ALT, AST and ALP activities as compared to the control rats. The toxicant, however did not cause any significant (p<0.05) change in absolute and relative weights of the testis and caudal epididymis of rats as compared to the control rats. Co-treatment of rats with P. thonningii leaf extract apparently subverted the induced-changes. Though, rats co-treated with the extract do not show visible signs of protection against AlCl₃ -induced sperm damage, serum activities of ALT, AST and ALP were significantly decreased following oral intake of the extract.
Conclusion: Data of the study suggest that AlCl3 exposure particularly through oral route at a dose of (0.5mg/kg b.w) is toxic and capable of inducing liver damage and testicular dysfunction in animals and possibly humans. Interestingly, Piliostigma thoninngii extract (methanolic) at a dose of 250mg/kg b.wt) was effective in protecting rats from liver damage induced by the toxicant.

Keywords: Piliostigma thonningii, aluminium, liver damage, testicular injury, rats.