EFFECTS OF GNETUM AFRICANUM WELW. AND OCIMUM GRATISSIMUM LINN. AQUEOUS LEAF EXTRACTS ON THE HAEMATOLOGICAL AND BIOCHEMICAL CHANGES IN CYANIDE-TREATED RATTUS RATTUS

Abstract

Cyanide toxicity is of public health concern. Cyanide is among the most potent and deadly poisons and sources of potential human exposure to it are numerous, arising through its release into the environment from both natural and anthropogenic sources. Gnetum Africanum (GA) and Ocimum Gratissimum (OG) which contain essential amino acids required to abate cyanide toxicity effects, are widely used local plants for both nutritional and therapeutic purposes in Nigeria. There is dearth of information about ameliorating effects of these plants on cyanide toxicity. The study was aimed at determining the effects of these plants on some indices of cyanide toxicity in Rattus rattus. Thirty 7-week old albino rats of same breed and similar exposure were randomly allocated to five treatment and one control groups of five rats each. Lyophilised aqueous extracts of GA and OG leaves were reconstituted in water to give a concentration of 3mg/L respectively while potassium cyanide (KCN) was prepared at 3mg/L concentration. After acclimatisation period of three weeks, the rats were randomly distributed as follow: group 1(control); group 2 (3mg/kg body weight KCN only); group 3 (3mg/kg body weight each of aqueous GA extract and KCN; group 4 (3mg/kg body weight each of aqueous OG extract and KCN); group 5 (3mg/kg aqueous GA extract only); group 6 (3mg/kg aqueous OG extract only). Treatments were administered by gavage while maintaining the rats on commercial rat pellets and water ad libitum for 14 days during which their body weights were noted daily. After exposure to the various treatments, biochemical analysis and haematological examination were done using the International Council for Standardisation in Haematology (ICSH) standard procedures. The results were analysed using descriptive statistics and Kruskal-Wallis at p=0.05. The mean rat weights (g) were significantly increased in group 3 (95.5+17.3) and group 5 (98.9+11.7) in comparison with the control (88.9+17.9). Slimy nasal discharge was found in 18.6% of rats in group 2 and 10.0% of rats in group 4. No discharge was found in control, group 3, group 5 and group 6. In group 2, 17.1% of the rats had ocular lesion while other groups had no ocular lesion. Mean haemoglobin values (g/dL) were significantly lowered in group 2 (12.9+0.7), group 3 (13.0+0.5), group 4 (13.1+0.5), group 5 (12.6+0.8) and group 6 (13.2+1.5) than the control (14.4+0.7) while mean white blood cell counts (cell/lmm3) were elevated with no significant difference with regards to the control. Total protein (g/dL) were significantly lowered except in group 2 than the control. Globulin production (g/dL) was suppressed significantly in groups 2 to 4 when compared with the control. Mean creatinine values (mg/dL) were increased in groups 2 to 6 than the control. Mean Aspartate aminotransferase values (unit/l) were significantly reduced in group 3 (9.6+2.5) than the control (21.6+5.5). Gnetum africanum and Ocimum gratissimum suppressed the haemopoietic system. Gnetum africanum had more deleterious effects and did not alleviate the haematologic and the biochemical effects of cyanide toxicity. The consumption of these plants with cyanoglycoside-containing food is not recommended.