ABSTRACT
Liver and kidney diseases represent major global problem all over the world. Toxic xenobiotic, alcohol consumption, malnutrition and medications, cause liver and renal damage due to exposure to high quantities of free radicals leading to oxidative stress.
The aim of this study was to evaluate the nutritional composition, phytochemical constituents and protective effect of Phoenix dactylifera L. (Zabiya and Siki cultivars) fruit extracts on sodium arsenate-induced toxicity in Wistar albino rats. Sets of male Wistar albino rats weighing between 100-120g were used for this study. The Wistar albino rats were divided into eleven groups of six rats each. Group 1, received normal saline and served as the normal control; Group 2, received sodium arsenate (2.5 mg/kg body wt.) alone (negative control); Group 3, received sodium arsenate + silymarin (100mg/kg b.wt; reference drug) while Groups 4,5,6,7,8,9,10 and 11 each received sodium arsenate concurrently with extracts of the two fruits cultivars for fourteen days. Sodium arsenate was administered intraperitoneally while the extracts / reference drug were administered orally using a gavage. The proximate composition of both fruit cultivars were found to contain high amounts of carbohydrate and moderate amounts of moisture, protein, crude fat, ash and fibre. Elemental analysis showed that both cultivars contained very high levels of k and Ca, moderate levels of Fe, Mg, Na, P and low amount of Zn. The results of the phytochemical screening (qualitative) of the fruit extracts (Zabiya and Siki cultivars) revealed the presence of alkaloids, tannins, flavonoids, phenols, saponins, anthraquinones, cardiac glycosides, steroids and terpenoids. However, anthraquinones were below detectable level in the siki cultivar. The quantitative analyses of the extracts showed that the hydroethanol fruit extract of Zabiya (Red fruit hydroethanol) had significantly increased (p< 0.05) levels of phenols and flavonoids (8.33±0.33GAE/g of extract and 41.08±0.31mgQE/g of extract respectively) in contrast to the other extracts. The ethanol fruit extract (Yellow fruit ethanol) of Siki showed considerably high (p< 0.05) levels of proanthocyanidins and tannins (8.66± mg ascorbic acid eq./g of extract and 62± mg Tannic acid eq/g of extract respectively). The ferric reducing antioxidant potential of the extracts was significantly high (p< 0.05) in the Red fruit hydroethanol and Yellow fruit ethanol extracts (173.35± an169.03±µmole Fe(11)/g of extract respectively ) while the DPPH radical scavenging ability of the extracts were more pronounced in the Red fruit hydroethanol and Yellow fruit ethanol extracts when compared with the other extracts. Results of the biochemical analyses revealed a significant increase (p< 0.05) in activities of liver function enzymes (ALT, AST, ALP and GGT), bilirubin, urea and creatinine levels in the serum of sodium arsenate – induced rats when compared with the control. The malonaldehyde level, which served as an index of lipid peroxidation, was significantly elevated in the sodium arsenate exposed rats while the superoxide dismutase activity was significantly reduced (p< 0.05). However, administration of the extracts of the date palm fruits reversed these changes to normal or close to normal levels. Among the fruit extracts, the red fruit hydroethanol extract at 250 mg/kg body weight (RFH250) appeared to have the most significant ability to reverse the destructive effect of the pro-oxidant, sodium arsenate. The ameliorative/ protective effect of the date palm extracts against sodium arsenate- induced liver and kidney injuries were further confirmed by the histopathological pattern observed in the tissues of rats treated with the fruits extracts.
