Nutritional and toxicological implications of drinking heat-treated fresh Raphia hookeri sap in rats

Abstract

Nutritional and toxicological implications of drinking heat-treated fresh Raphia hookeri sap (HTFRhS) in place of water were studied in rats. Seven to eight weeks old healthy albino Rattus norvegicus of the Wistar strain of both sexes (n = 8 per group) that weighed 57.46±0.91 g were used. Test rats drank HTFRhS (40.10 mg/ ml, pH 6.36±0.00 at 29.37±1.0oC) for 35 days in place of water after heating it to 85oC (to halt fermentation and distill off pre-formed ethanol) and cooled. Control rats drank only tap water. Body weights, feed and fluid intakes, organ (liver, kidneys, spleen and heart) weights, haematological parameters (like haemoglobin, Hb; packed cell volume, PCV; mean corpuscular haemoglobin concentration, MCHC; white blood cells, WBC), liver function indices and serum lipid profile were evaluated at the end of the study. HTFRhS did not contain ethanol. When the HTFRhS was administered to the rats, there was no significant difference (p>0.05) between the HTFRhS-treated rats and control rats for feed conversion ratio (FCR), haematological parameters and organ weights. Serum AST and ALT activities however increased significantly (p<0.05) on consumption of HTFRhS. Serum AST/ALT ratios showed that HTFRhS was more hepato-toxic to the male rats (ratio: 0.98±0.05) and more cardio-toxic to the female rats (ratio: 1.05±0.04). Serum albumin/ globulin ratios of HTFRhS-treated rats increased significantly (p<0.05) presenting a symptom of xanthomatosis. Serum [LDL-cholesterol] of HTFRhS-treated rats increased while their serum [HDL-cholesterol] decreased. Their serum total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios indicated atherogenicity; with the female rats being more (p<0.05) susceptible. In conclusion, the heat-treated fresh palm sap was not safe when drunk in place of water.