ABSTRACT
Mercury is a highly toxic metal that exerts its adverse effects on the health of humans and animals worldwide. The present study was aimed at evaluating the protective effects of aqueous and ethanol extracts of Phoenix dactylifera L. on mercury induced liver and kidney damage in Wistar rats. A total of forty five (45) male Wistar rats of (80 - 125g) were randomly divided into nine groups (I-IX) of five (5) rats each. Group 1 served as the Control and was administered distilled water (0.5 ml), Group II was administered mercury chloride (HgCl2) only at 5 mg/kg body weight (bwt); Group III was pretreated with silymarin at 100 mg/kgbwt then followed by HgCl2 at5 mg/kgbwt; Groups IV and V were pretreated with aqueous fruit extract of Phoenix dactylifera (AFPD) at 500 mg/kgbwt and 1000 mg/kgbwt, respectively, followed by HgCl2 at 5 mg/kgbwt; Groups VI and VII were pretreated withethanol fruit extract of Phoenix dactylifera(EFPD) at 500mg/kgbwt and 1000 mg/kgbwt, respectively, followed by HgCl2 at 5 mg/kgbwt, while Groups VIII and IX were pretreated with AFPD and EFPD only at 1000 mg/kgbwt, respectively. After two weeks of oral administration, the animals were sacrificed using cervical dislocation method and blood samples were collected through the jugular vein for biochemical studies (liver serum enzymes: Aspartate transaminase (AST), Alaninetransaminase (ALT) and Alkaline phosphatase (ALP); and oxidative stress markers, Malondialdehyde (MDA), Superoxide dismutase (SOD), Catalase (CAT) and Glutathione peroxide (GPx). Tissue samples of the liver and kidney were collected and processed for light microscopy using routineHaematoxylin and Eosin (H&E), Periodic Acid Schiff (PAS) and Gordon and Sweet (GS) stains. The results of the present study showed that toxicity and oxidative stress were induced by the significant increased levels of AST, ALP and MDA (p<0.05) and decreased levels of SOD, CAT and GPx when compared to the Control. Histological and histochemical changes in the liver and kidney revealed severe degenerative changes, such as hepatocellular vacuolation, sinusoidal dilatation, pyknotic nuclei and cytoplasmic vacuolation in rats exposed to HgCl2 when compared to the Control. The administration of extracts of AFPD and EFPDpreserved liver serum enzymes, kidney electrolytes and antioxidant enzyme activities to levels similar to that of the Control and provided protection against mercury-induced changes in the liver and kidney of Wistar rats. The protective activities of the extracts of Phoenix dactylifera could be attributed to the antioxidant properties such as flavonoids. Thus, these extracts could be potential candidates for use in the management and treatment of mercury-related liver and kidney diseases in our localities.