EFFECTS OF AQUEOUS EXTRACTS OF vernonia amygdalina AND talimum triangulare ON INDUCED CYANDE POISONING IN WISTAR RATS

Abstract

There is a risk of cyanide poisoning in Nigeria through environmental exposure and consumption of improperly processed cyanide containing foods. Sulphur containing amino acids in vegetables like Vernonia amygdalina (bitter leaf) and Talinum triangulare (water leaf) have potential detoxifying effects on cyanide poisoning. However, there is dearth of information about the ameliorating effects of these vegetables on cyanide poisoning when used as dietary supplements in animal models. The study was therefore designed to assess the effect of these two vegetables on induced cyanide poisoning in Wistar rats.

Thirty 7 weeks old Wistar rats with mean body weight of (123.97± 17.7) gm, (124.9± 16.7) gm, (141.4± 21.0) gm, (128.4± 23.6) gm, (145.0±11.1) gm, (118.5±13.1) gm and (129.1± 18.5) gm were fed on commercial rat pellets and water ad-libitum for two weeks and were randomly allocated to one control group and five treatment groups of five rats each. Lyophilized water extracts of Vernonia amygdalina and Talinum triangulare were reconstituted in water to give a concentration of 3mg/kg/day. The groups were treated with KCN and aqueous vegetable extracts both at dose of 3mg/kg/day by oral gavage as follows: Aqueous KCN (group 1); KCN and Vernonia amygdalina extracts (group 2); KCN and Talinum triangulare extracts (group 3); Vernonia amygdalina extracts only (group 4); Talinum triangulare extracts only (group 5). The control group was treated with distilled water only (group 6. Body weight, presence of ocular lesion, and nasal discharge were documented daily. Elevated blood level of Aspartate Amino Transminase (AST) and Alanine Amino-Transminase (ALT) were used as indicators for liver damage. Histopathological changes in the brain, liver, kidney and spleen were documented. Data were analyzed using descriptive statistics, Student’s t-test and ANOVA.

Slimy nasal discharge was found in 20.0% of rats in group 1 and 9.8% in group 5 only. There were no visible signs of ocular lesions in all rats. Mean values for AST were: 29.0±8.8 U/L , 33.0±5.2 U/L, 18.7±7.6 U/L, 24.7±13.3 U/L, 16.0±7.2 U/L and 20.7±6.1 U/L (p>0.05) for groups 1 to 6 respectively. Mean values for ALT were; 17.7±3.5 U/L, 18.0±7.0 U/L, 22.3±8.6 U/L, 22.3±5.1 U/L, 17.3±4.7 U/L and 21.3±7.1 U/L (p>0.05) for groups 1 to 6 respectively. Packed cell volume significantly increased in group 4 (45.2±3.3) as compared with control (37.0±4.4)(p<0.05). Haemoglobin significantly increased in group 4 (14.0±2.3)when compared with control (12.4±0.5) (p<0.05). Histopathological changes observed with cyanide in group 1 was: multifocal fatty and portal lymphocytic degeneration of the liver; congestion, necrosis and glomerular cast of the kidney and splenic lymphoid depletion.

Vernonia amygdalina and Talinum triangulare reduced cyanide toxicity in rats implying that they have some detoxification properties. Bioassay fractionating of the vegetables is recommended to isolate and identify the molecules responsible for the activities.