Effect of aqueous leaves extract of Costus afer Ker Gawl (Zingiberaceae) on the liver and kidney of male albino Wistar rat

BACKGROUND: The use of medicinal plants in Nigeria has significantly increased over recent years as it is easily accessible, cheap and the strong belief that herbal remedies are natural and therefore non toxic. AIMS: This study aims to investigate the sub-chronic toxicity (28-day) of the aqueous extract of Costus afer Ker Gawl leaves on the liver and kidney of male albino Wistar rats. MATERIALS AND METHODS: A total of 20 male albino Wistar rats (113-205 g) divided into four groups of five weight-matched animals each, were used for the study. Group 1 received standard feed and water ad libitium and served as the control. Group 2, 3 and 4 received 375, 750 and 1125 mg/kg of aqueous extract of C. afer leaves respectively. The animals were sacrificed under ether anesthesia and the organs were harvested, weighed and histopathological studies carried out. The effect of C. afer on the hepatic biomarkers aspartate aminotransferase (AST), alanine aminotransferase (ALT); alkaline phosphatase (ALP); triglyceride (TG); total bilirubin (TB); conjugated bilirubin (CB); albumin (ALB) and kidney biomarkers urea, creatinine, sodium, potassium and bicarbonate were investigated. STATISTICAL ANALYSIS: Data were evaluated using Mann Whitney. If P ≤ 0.05 groups were considered to be significantly different. RESULTS: C. afer contained alkaloids, saponins, flavonoids, anthraquinones, cardiac glycosides, terpenoids, phenolic compounds and tannins. The average body, organ, relative weights, feed and fluid intake showed no significant changes (P > 0.05) when compared to the control. The liver function tests (ALT, ALP, AST, CB, TB and ALB) showed significant differences (P < 0.05) in the test groups when compared with the control while TG showed no statistical difference (P > 0.05). The kidney function tests (urea, creatinine, sodium, potassium and bicarbonate) showed no significant differences (P > 0.05) in the test groups when compared to the control. CONCLUSION: Costus afer may be hepatotoxic but non-toxic to the kidney.