Phytochemical Composition and the Effects of Aqueous Extract of Tigernut Tuber on the Haematology and Serum Biochemistry of Albino Rats

Abstract

The phytochemical composition of the tigernut tuber was determined and the effects of its aqueous extract on haematological and biochemical parameters were determined in rats administered different concentrations of the extract. The presence of alkaloids, cyanogenic glycosides, resins, tannins, sterols, and saponins were observed in the raw tuber, however only alkaloids, sterols and resins were observed in the roasted tuber. Analysis of the antinutrient composition yielded oxalates (0.25±0.65 g/100g), phytate (1.97±0.81 mg/100 g), saponins (0.88±0.02 g/100 g), tannins (9.50±0.46 mg/100 g) and cyanogenic glycosides (1.80±0.69 mg/100g). Roasting numerically decreased the levels of the anti-nutritive factors analysed. At the end of the treatment period, the mean weights of the animals increased. The blood glucose level decreased significantly in concentration dependent manner (p<0.05), while serum albumin level increased significantly in a concentration dependent manner (p<0.05) in the groups administered the different concentrations of the extract. There was no significant effect (p>0.05) on serum cholesterol and protein and on total and differential white blood cell, red blood cell, haemoglobin, packed cell volume, and erythrocyte sedimentation rate. The results therefore indicate the absence of undesirable effect in the use of the tigernut tuber even in the raw form at least at the administered concentration and for the duration of feeding. These findings are of nutritional, health and industrial relevance since the tuber is currently being used as food in many homes in Nigeria.