Fatty Acid Profile and Anti-Inflammatory Activity of Fixed Plant Oils

Abstract

Background: Many seed oils have been used as anti-inflammatory agents, administred by ingestion or topical application in traditional medicine. The objective of this research was to perform a chemical analysis of fatty profile and a pharmacological study through a topical experiment of TPA-induced ear edema test and an internal assay - acetic acid-induced vascular permeability in Swiss mice of some fixed oils popularly used for inflammatory problems, trying to confirm their action.

Materials, Methods & Results: Fixed lipids of Ouratea fieldingiana (batiputá), Caryocar coreaceum (pequi), Annacardium occidentale (cashew-nuts), Cocos nucifera (coco-da-bahia), Byrsonima crassifolia (murici) e Elaeis guineenses (palm) were selected for the identification of fatty acids profile by gas chromatography coupled to mass spectrometry (GC/MS) analysis and evaluation of anti-inflammatory activity by TPA-induced ear edema test and acetic acid-induced vascular permeability in Swiss male mice. The oils were purchased in local markets or extracted in Soxhlet apparatus with hexane. The oils of cashew nut, murici fruit, and pequi nut presented a high percentage of unsaturated fatty acids (81.80, 74.46 and 60.72 %, respectively). In the oils of batiputá and murici, linoleic acid was the main unsaturated fatty acid (45.06% and 74.66%, respectively) and oleic acid was main constituent in cashew nut, pequi and palm seed oils. Batiputá and palm oils exibit approximately equivalent content of saturated and unsaturated fatty acid and coconut oil more saturated fatty acids (80.72%) with predominance of lauric acid. The result of TPA-induced ear edema test revealed that all oils presented similar anti-inflammatory activity. In the acetic acid-induced vascular permeability model, the oil of O. fieldingiana was the only one who showed anti-inflammatory activity, while C. coreaceum and B. crassifolia oils showed pro-inflammatory activities. The presence of phenols and flavonoids was evaluated in the O. fieldingiana oil by spectrophometric methods.

Discussion: All the oils showed anti-inflammatory action in the TPA-induced ear edema, probably the action of unsaturated fatty acids was more important in topical application, nevertheless in internal inflammation process the presence of antioxidant phenolic compounds could contribute to the higher activity of the oil from O. fieldingiana. The effect of linoleic and oleic acids was demonstrated on the inflammatory response of the skin during the healing process and on the release of pro-inflammatory cytokines by rat neutrophils in a prevoius study using sunflower oil. Both oleic and linoleic acids increased the wound healing tissue mass. The total protein and DNA contents of the wounds were increased by the treatment with linoleic acid. This pro-inflammatory effect of oleic and linoleic acids may contribute to the wound healing process. In this study with six plant oils, some of them have higher content in linoleic acid and others oleic acid is the major constituent so the antiinflamatory action on ear edema can be associated to these two unsaturaded fatty acids mechanism of action. In the internal model, probably other chemical constituents revealed in Ouratea fieldingiana as phenols, condensed tannins, flavones and flavanones, could contribute to the anti-inflammatory activity.