Sesame Oil and Rice Bran Oil Ameliorates Adjuvant-Induced Arthritis in Rats: Distinguishing the Role of Minor Components and Fatty Acids.

Though present in small amounts, the minor constituents of dietary oils may supplement the dietary therapies for rheumatoid arthritis (RA). Hence, in the present study, we assessed the effect of minor constituents from sesame oil (SO) and rice bran oil (RBO) and their fatty acids on the severity of adjuvant-induced arthritis in experimental rats. Rats were gavaged with 1 mL of SO or RBO or groundnut oil (GNO, control) with or without its minor components for a period 15 days before and 15 days after the induction of arthritis. Oxidative stress, markers of RA, eicosanoids, cytokines, paw swelling and joint integrity were measured in experimental and control rats. Results demonstrated that native SO and RBO but not SO and RBO stripped of their minor components decreased severity of paw inflammation, oxidative stress (lipid peroxides, protein carbonyls, nitric oxide), RA markers (RF and CRP), inflammatory eicosanoids (PGE2, LTB4 and LTC4) and cytokines (IL-1ß, IL-6, MCP-1 and TNF-α) compared to control rats. Native SO and RBO inhibited hydrolytic enzymes (collagenase, elastase and hyaluronidase) in the synovial tissue compared to SO and RBO without minor components. The arthritic scores assessed based on the digital and X-ray images indicated that native oils but not those without their minor components reduced the paw swelling and bone loss. Our results indicated that minor components of SO and RBO possess a significant degree of an anti-arthritic effect and are responsible for down regulating inflammation in the experimentally induced arthritis in rats.

Rats fed blended oils containing coconut oil with groundnut oil or olive oil showed an enhanced activity of hepatic antioxidant enzymes and a reduction in LDL oxidation.

The effects of feeding Wistar rats with blended and interesterified oils of coconut (CO):groundnut (GNO) or CO:olive (OLO) on liver antioxidant enzyme activities and susceptibility of LDL to oxidation were studied. The hepatic lipid peroxidation (LPO) levels in the rats fed CO:GNO blend and interesterified oils were increased by 31% and 21%, when compared to the rats given CO. The superoxide dismutase activity was increased by 31% and 28%, and catalase (CAT) activity was increased by 37% and 39%, respectively, in rats given blends and interesterified oils of CO:GNO, as compared to those given CO. The activities of glutathione peroxidase (GPx) were increased by 17% and 20% in rats given CO:GNO blend and interesterified oils. Glutathione transferase (GST) level was also found to be increased by 26% and 31% after feeding blended and interesterified oils of CO:GNO, compared to those given CO. The LDL oxidation, which was elevated by feeding GNO, was found to be reduced by 10% and 14%, respectively, in the groups fed blended and interesterified oils of CO:GNO. Similarly, CO:OLO blended oils enhanced SOD, CAT, GPx and GST activities by 34%, 43%, 27% and 23%, respectively, compared to the rats given CO-containing diets. The corresponding increases in theses antioxidant enzyme activities when CO:OLO interesterified oils were fed to rats were 38%, 50%, 28% and 26%, respectively, when compared to rats given CO-containing diets. There was a significant reduction in hepatic LPO as well as oxidation of LDL, when blended and interesterified oils of CO:OLO were fed to rats. The results demonstrated that blended and interesterified oils of CO with GNO or OLO enhance hepatic antioxidant enzymes, decreased lipid peroxidation in liver and reduced the susceptibility of LDL to oxidation.