Evaluation of Analgesic Effect of Sesame Oil and Lecithin Diets in Hot Plate and Formalin Test on Aged Male Rats

Sesame oil is applied in physiological research as a solvent. It contains unsaturated fatty acids such as linoleic acid, sesamol and lecithin. In his research effect of dietary sesame oil on pain perception was studied. N-MRI male rats (360±20 g) were used. Animals divided to two groups: 1) control group and 2) experimental group (three subgroups that ate dietary plats that contain 10% sesame oil for 28, 42 and 56 days respectively and a subgroup ate dietary plats that contain 1% lecithin). After 28, 42 and 56 days pain was evaluateded by digital hot plate and formalin test. Data was analyzed by one way ANOVA or T- test. Hot plate test: Sesame oil diet decreased pain in the 28, 42, 56 days significantly. Formalin test: Sesame oil diet decreased pain only in 42 days (p<0.02) significantly in early phase. Sesame oil diet decreased pain in the 28 days (p<0.0001) and 42 days (p<0.03) and 56 days (p<0.001) significantly in late phase of formalin test and also we found significant difference between control and lecithin group (p<0.006) in late phase.Hot plate test: Dietary plats (10% sesame oil) decreased acute pain perception in all experimental groups (p<0.03). Our data indicated that dietary sesame oil could increase pain threshold. It seems that sesame oil lecithin (as a source for acetylcholine) or unsaturated fatty acid (altered plasma membrane properties or PGs metabolism) involve in this pain threshold alternation.