Evaluation of anti-inflammatory activity of plant lipids containing alpha-linolenic acid

Two groups of fatty acids are essential to the body, the omega6 (n6) series derived from linoleic acid (18:2, n-6) and the omega3 (n3) series derived from alpha-linolenic acid (18:3, n-3). Fatty acids provide energy, are an integral part of the cell membranes and are precursors of prostaglandins, thromboxanes and leukotrienes collectively known as eicosanoids. Eicosanoids participate in development and synthesis of immunological and inflammatory responses. The fixed oils (1, 2, 3 ml/kg) containing alpha-linolenic acid, obtained from the seeds of Linseed (Linum usitatissimum), Soyabean (Glycine max) and Holy basil (Ocimum sanctum) were screened for their antiinflammatory activity using carrageenan, leukotriene and arachidonic acid induced paw edema models in rats and the antiinflammatory effects were compared with the standard drug indomethacin. Significant inhibition of paw edema was produced by all the oils in the highest dose (3 ml/kg) in all the models. While O. sanctum oil produced the maximum percentage inhibition in leukotriene induced paw edema, L. usitatissimum oil produced maximum percentage inhibition in carrageenan and arachidonic acid induced paw edema models. The results show that oils with higher alpha-linolenic acid content (L. usitatissimum and O. sanctum) produced a greater inhibition of paw edema suggesting that modulation of the course of inflammatory disorders may be achieved by altering the eicosanoid precursor (i.e. poly unsaturated fatty acids: PUFA) availability through dietary manipulation.