Antinociceptive and Anti-inflammatory Efficacy of Oleic and Linoleic Acid Application

Abstract

The present study aimed to comparatively evaluate the antinociceptive and anti-inflammatory effects of oleic acid (OA) and linoleic acid (LA), administered individually and in combination, and to investigate their impact on serum pro-inflammatory cytokines in an experimental animal model. A total of 96 rats were orally treated with OA (45–90 mg/kg), LA (45–90 mg/kg), OA + LA (45+45 mg/kg and 90+90 mg/kg), standard analgesics (indomethacin and acetylsalicylic acid, ASA), or vehicle control. The antinociceptive properties were examined through Tail Flick, Hot Plate, and writhing test induced by acetic acid injection, whereas the anti-inflammatory properties were examined through carrageenan-induced paw edema. The concentrations of TNF-α and IL-1β in serum were determined by ELISA. OA demonstrated statistically significant antinociceptive effects in both central and peripheral pain models, exhibiting efficacy comparable to ASA. In contrast, LA alone did not produce significant analgesic effects. Notably, co-administration of OA and LA attenuated the analgesic efficacy observed with OA alone. In the carrageenan-induced inflammation model, both OA and OA + LA significantly reduced paw edema, with effects comparable to indomethacin, whereas LA alone showed limited anti-inflammatory activity. Biochemically, both OA and LA significantly elevated serum TNF-α levels, while no significant differences were observed among groups in IL-1β levels. These findings suggest that OA possesses pronounced antinociceptive and anti-inflammatory properties. However, the reduced efficacy observed with combined administration and the elevation of cytokines indicate that OA and LA might work via different pathways, thus warranting further investigation into their dose-dependent interactions.