A study on protective effects of low dietary pufa levels in hypertensive rats.

ABSTRACT

Background & objectives: Short term dietary supplementation of eicosapentanoic acid [EPA, 205(ω-3)] and docosahexanoic acid *DHA, 226(ω-3)] in high amounts to prevent cardiovascular diseases have been reported. The present study investigates the effects of long term dietary supplementation of low PUFAs in a cereal-legume diet on plasma fatty acid composition, platelet function and cadmium induced hypertension in male Charles foster rats. Materials and Methods: Rats were fed with 3% of safflower oil, groundnut oil or linseed oil, in a cereal-legume based diet (total fat content, 5.5%) for a period of six months. Plasma fatty acid composition, platelet aggregation and blood pressure of four groups with fifteen rats each namely Safflower (S), Groundnut (G), Linseed (L) and Control (C) group were studied . Blood pressure was measured after administration of intraperitoneal cadmium chloride (i.p. dose, 1mg/kg body weight) for fifteen days. Results and Interpretation: The ω-3 fatty acids were found to be significantly higher (T-test, p<0.005) in the plasma of rats fed on Linseed oil. There was an increased platelet aggregatory response to adenosine diphosphate (ADP) in rats fed with groundnut oil (G group). The platelet aggregation (%) and rate of aggregation between groups were found to be significantly low in the Linseed oil group indicating the impact of diet on membrane function. The systolic blood pressure was found to be significantly different between groups (ANOVA test) after cadmium treatment at level of p<0.05. Incidence of blood pressure was highest in rats supplemented with Groundnut oil (G, 66%) followed by control group (C, 50%). The incidence was least in the groups supplemented with Safflower and Linseed oils (S & L- 33%) in cadmium treated showing protective effect of PUFAs on blood pressure. Conclusion: It can be concluded from the study that long term supplementation of low dietary PUFA shows significant changes in plasma fatty acid composition, platelet aggregation thereby affecting the blood pressure. As cereals and legumes contain cardioprotective flavonoids, the combined effect of PUFA and flavonoids needs to be evaluated.