Studies On Neem Seed Toxicity To Rats And Chicks

Abstract

The medicinal and toxic plants used therapeutically in traditional medicine are reviewed with emphasis on the Neem A .indica tree, covering its active ingredients and uses in agriculture, human and veterinary medicine. This study was designed to investigate the toxicity of the methanolic extracts of A .indica whole seed and seed kernel at different doses to rats and chicks via both oral and intraperitoneal routes. The anti-inflammatory potential of both extracts was tested in rats by oedematous reaction inhibition. Both methanolic whole seed and seed kernel extracts were tested, using for each 42 albino rats arranged in 7groups (Control + 6 test groups). Three test groups were used for either intaperitoneal or oral dosing at 500, 1000 and 2000 mg/kg body wt./rat/day, continued for four weeks. The two extracts were also tested likewise in cockerels using 48 day-old Bovans chicks for each test in a 4x12 arrangement (Control + 3 test groups). Test dosing of 100, 200 and 500 mg/kg body wt. /chick was administered by oral intubation. Dosing was continued for four weeks. Half survival animals were slaughtered at the end of week 2 and the rest at the end of week 4. Fifty Albino rats were used to test the anti-inflammatory activity of the two extracts. For either extract, 25 rats were used in 5 groups receiving intraperitoneal dose rates of 250, 500, 1000 mg extract /kg body weight/rat, 10 mg indomethacine ( reference anti-inflammatory) /kg body weight/rat and 1ml /kg body weight/rat of normal saline (control). All individuals were injected 30 minutes subsequent to extract injection subcutaneously with a local acute oedema inducer (0.1 ml of a 10% w/v carrageenan saline suspension) in the sub-planter region of the left hind limb. Oedema size was monitored at 1, 2, 4, 6 and 24 hours. Clinical signs were observed regularly. Sera were analyzed for enzymatic concentrations of ALP, GOT and GPT and metabolic indicators albumin, total protein, bilirubin, urea, creatinine and glucose. Also hematological changes in Hb, PCV, RBCs and WBCs were recorded. Tissue specimens of liver, kidneys, heart, intestines and spleen were examined for histopathology. The diameter of the hind paw was measured in assessment of the oedema size. Clinically no signs of toxicity were observed nor death or changes in the examined vital organs. Toxicity of both extracts was characterized by hepatonephropathies as sever necrosis and fatty change in the liver and kidneys, beside wide spread of hemorrhages and congestions in different vital organs. These changes were correlated with significant (P<0.001) increases in the serum (ALP) and (GOT) activities and in the serum metabolites bilirubin, urea and total protein. Also there was a significant (P<0.001) increase in the values of WBCs, Hb and PCV. In this study no findings in the toxicity to chicks that differs remarkably from rats. Both extracts showed high anti-inflammatory efficacies against carrageenan-induced paw edema in rats at the 4th hour. The seed kernel methanolic extract highly (P<0.001) decreased the odema size at efficacy rates 79.40, 88.90 and 84.70 % for doses 250, 500 and 1000 mg/kg body weight respectively which were higher than the reference indomethacine ( 70.80 %). The whole seed methanolic extract brought about a significant (P<0.05 – 0.01) decrease in the odema size with efficacy rates of 51.20 and 70.70 % respective to doses 250 and 1000 mg/kg body weight. However, these effects were weaker than the reference compound (78.00 %). The practical implications of these results were discussed with suggestions for future studies.