THE EFFECT OF DIET AND AFLATOXIN INTAKE OF BLOOD-CLOTTING TIME AND SOME SERUM CONSTITUENTS IN NON-HUMAN PRIMATE

Abstract

The effects of diet and aflatoxin intake on blood coagulation and serum lipid levels investigated in four different species of non-human primates namely, Carcopithecus aethiops Tantalus, Erythrocebus patas, Cercopithecus mona, and Papio anubis. Green monkeys (Cercopithecous aethiops, Tantalum) subsisting on high-fat (18.1%) and high-protein (25.1%) diets respectively exhibited significant (P<0.001) decreases in their clotting times when compared with the control. The high-fat diet caused a significant elevation of serum free cholesterol, total cholesterol, and phospholipid levels with a significant (P<0.001) increase in the total cholesterol/phospholipid ratio. On the contrary, the high-protein diet decreased these lipid components. This effect was not statistically significant (P>0.05) and there was no significant change in the total cholesterol/phospholipid ratio. In both the high-fat and the high-protein groups, increases and decreases, respectively in free cholesterol paralled those of total cholesterol and there were no statistically significant (P>0.05) increases or decrease in the cholesterol/total cholesterol ratios. These results suggest that diet affects the blood-clotting time and serum lipid levels of these non-human primates. A stock diet infested with a toxic strain of Aspergillus flavus induced a significant (P< 0.001) prolongation of blood-clotting time in these experimental non-human primates. A similar observation was made when the experimental animals were given a mixture of aflatoxins in the diet or graded doses (60µg, 80 µg and 100 µg /kg of body weight, respectively) of pure aflatoxin B1, administered intraperitoneally. However, the prolongation of blood-clotting time by the 60µg /kg dose of the toxin was not statistically significant (P> 0.05). The peak action of the toxin was reached after one hour of an intraperitoneal administration of aflatoxln.. Aflatoxin - induced prolongation of blood-clotting time in Green monkeys (Cercopithecus aethiops, Tantalus). Patas monkeys (Erythrocobus patas), Mona monkeys (Cercopithecus mona) and Anubis baboons (Papio anubis) was found to be species dependent. Graded doses of aflatoxin B1, (60µg, 80 µg and 100 µg /kg of body weight, respectively) prolonged the plasma prothrombin tlme of Green monkeys. However, only the 100 µg /kg dose caused a significant (P< 0.001) prolongation of prothrombin tlme. All doses of aflatoxln did not significantly the packed cell volume and haemoglobin concentration of the experimental monkeys. The effects of a mouldy diet and also graded doses (60µg, 80 µg and 100 µg /kg) of aflatoxin B1, administered intraperitoneally, on serum free cholesterol, serum total cholesterol, serum total phospholipids and total serum lipids were determined in the experimental monkeys. These lipid components were decreased significantly in all the monkeys by all doses of aflatoxin, including the 60µg/kg dose which did not prolong blood-clotting time significantly. Therefore, aflatoxin-induced depression of serum lipids in these non-human primates, as suggested by these results, is a distinct effect from its action on blood-clotting time. Species differences have also been observed in aflatoxin-induced depression of serum lipid levels since all lipid fractions were not reduced to the same extent by any given dose of aflatoxin in the four species of non-human primates studied. A significant dose - response relationship has been demonstrated between the amount of aflatoxin admistered and changes in serum lipid levels. Clinical hepatic function tests suggest that one hour of after an intraperitoneal Injection of aflatoxin (when the toxin has been shown to lengthen blood-clotting time maximally) and also after an interval of forty-eight hours (when the Monkeys had been exposed to a longer period of action of the toxin), there was no appreciable disturbance of liver function. There were no significant differences in the levels of serum alkaline phosphatase, serum glutomic oxalacetic transaminase and serum bilirubin and no positive results were observed with the thymol turbidity test. The effects of a high-fat (18.1%) diet on the blood-clotting time and serum lipid levels during aflatoxicosic in the experimental monkey were investigated. Aflatoxin prolonged blood-clotting time and depressed serum cholesterol, phospho-lipids and total serum lipid levels at all concentrations of dietary fat. However, there was a statistically significant interaction between aflatoxin and fat level such that the blood-clotting time and serum lipid levels approached the control values when aflatoxin was given to the monkeys on the high-fat diet. These findings indicate that dietary fat affects not only aflatoxin-induced prolongation of blood-clotting time but also depression of serum lipid levels in these non-human primates and suggest one way by which the effect of diet could be mediated. The results are discussed.