Antiinflammatory, analgesic and antipyretic activities of Linum usitatissimum L. (flaxseed/linseed) fixed oil
Antiinflammatory, analgesic and antipyretic activities of Linum usitatissimum L. (flaxseed/linseed) fixed oil
Year: 2011
Authors: Kaithwas, G. Mukherjee, A. Chaurasia, A.K. Majumdar, D.K.
Publication Name: Indian Journal of Experimental Biology
Publication Details: Volume 49; Pages 932 – 938.
Abstract:
The fixed oil of L. utisatissimum (flaxseed/linseed) inhibited PGE 2, leukotriene, histamine and bradykinin induced inflammation. The oil also inhibited arachidonic acid induced inflammation, suggesting its capacity to inhibit both cyclooxygenase and lipoxygenase pathways of arachidonate metabolism. In tail immersion model, the oil raised the pain threshold to a lesser extent than morphine but showed excellent peripherally acting, analgesic activity comparable to aspirin, against acetic acid-induced writhing in mouse. The oil contains 57.38% alpha linolenic acid (ALA). Dual inhibition of arachidonic acid metabolism, antihistamine and antibradykinin activities of the oil could account for the biological activity and the active principle could be ALA an omega 3 (18:3 n3) fatty acid. (Authors abstract)
The present study has been undertaken to evaluate the antiinflammatory, analgesic and antipyretic potential of flaxseed fixed oil. In order to explore the effect of route of administration on antiinflammatory activity, activity of L. utisatissimum fixed oil was evaluated against carrageenan and PGE induced paw edema in rats following administration of oil by oral, intramuscular and intraperitoneal routes. In carrageenan induced paw edema model significant inhibition (34.38%) of paw edema was observed after oral administration of oil but the extent of edema inhibition was inferior to that observed with intramuscular (62.34%) and intraperitoneal (69.35%) administration. Similarly in prostaglandin induced paw edema model oral administration of the oil produced 14.29% inhibition which was much smaller than the edema inhibition obtained with intramuscular (55.55%) and intrperitoneal (80.88%) administration. The oil also inhibited prostaglandin E2 (PGE2) induced inflammation. Hence, subsequently, the anti-inflammatory effect of L. utisatissimum oil was evaluated against other inflammatory mediators like leukotriene, histamine, and bradykinin. In leukotriene induced edema the oil significantly inhibited the edema (72.6%) comparable to ketoconazole (a leukotriene antagonist) (79.45%). In histamine-induced edema, the oil significantly inhibited the edema (62.31%). Similarly the oil inhibited bradykinin induced edema (84.28%). The results suggest that flax oil possesses anti-prostaglandin, antileukotriene, antihistaminic and antibradykinin effects; and that flax oil has the capacity to inhibit the synthesis of prostaglandin and leukotrienes by cyclooxygenase and lipoxygenase from arachidonic acid substrate. PGE2, a powerful vasodilator, synergizes with other inflammatory vasodilators such as histamine and bradykinin and the combined dilator action on pre-capillary arterioles contributes to the redness and increased blood flow in areas of acute inflammation. PGE2, on its own, does not increase the permeability of post-capillary venules but potentiates the effect of histamine and bradykinin to increase permeability. Flax oil, by inhibition prostaglandin E2 (PGE2), leukotriene B4 (LTB4), histamine and bradykinin could render anti-inflammatory effect. Flax oil was well tolerated up to 20 ml/kg in acute toxicity study. Administration for a longer duration of time in sub-acute toxicity studies did not reveal negative effects of the oil on behaviour, body weight, normal reflexes and visceral appearance in rats. The oil did not produce ulcerogenic effect nor any histopathological changes. The authors concluded that ALA in flax oil possesses anti-inflammatory, analgesic and antipyretic activities. Dual inhibition of arachidonic acid metabolism, antihistaminic and antibradykinin activities of flax oil could account for the biological activity. (Editors comments)
