Aluminium-induced liver and testicular damage: effects of Piliostigma thonningii methanolic leaf extract

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.

The protective potential of Piliostigma thonningii (250 mg/kg of body weight) methanolic leaf extract on aluminium-induced hepatotoxic and testicular damage in Wister rats was studied.

Toxicity was induced in experimental animals via oral route using 0.5 mg 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 0:5 ml of olive oil (vehicle for the extract) and 1 ml of saline (vehicle for the toxicant), a second group treated with 0.5 mg of AlCl3 (toxicant) per kg bwt and a third group treated with 0.5 mg of AlCl3 and 250 mg 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.

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.

Data of the study suggest that AlCl3 exposure particularly through oral route at a dose of (0.5 mg/kg b.w) is toxic and capable of inducing liver damage and testicular dysfunction in animals and possibly humans. Interestingly, Piliostigma thonningii extract (methanolic) at a dose of 250 mg/kg b.wt) was effective in protecting rats from liver damage induced by the toxicant.