Dietary Supplementation with Raspberry Seed Oil Modulates Liver Functions, Inflammatory State, and Lipid Metabolism in Rats.

BACKGROUND Although raspberry seed oil (RO) is rich in essential fatty acids, there is a lack of experiments assessing benefits of its consumption. OBJECTIVE We investigated the effects of dietary supplementation with RO on healthy rats and rats with low-grade systemic inflammation, liver disorders, and dyslipidemia induced by a high-fat/low-fiber (HF/LF) diet. METHODS Thirty-two rats were allocated into 4 groups of 8 rats each and fed for 8 wk a control (C; 7% lard and 5% cellulose) or HF/LF (21% lard and 2% cellulose) diet or modifications of these diets in which 7% RO replaced all (C+RO group) or a proportion of (HF/LF+RO group) the lard. Effects of diet and RO and their interaction on bacterial activity and metabolite formations in the distal intestine, liver fat and glutathione concentration, plasma lipid profile, transaminase activities, and plasma concentrations of C-reactive protein (CRP) and tumor necrosis factor α (TNF-α) were tested. RESULTS Dietary RO decreased plasma alanine and aspartate transaminase activities (43.4 and 157 vs. 25.6 and 115 U/L, respectively; P < 0.05 and P < 0.005) and plasma TNF-α and triglyceride concentrations (132 pg/mL and 2.07 mmol/L vs. 86.5 pg/mL and 0.99 mmol/L, respectively; P < 0.05). In livers of the C+RO group, the fat concentration was decreased, whereas the glutathione to glutathione disulfide ratio was increased compared with the C group (30.1% and 6.20 μmol/g vs. 23.3% and 7.25 μmol/g, respectively; P ≤ 0.05); however, those differences were not observed between the HF/LF groups (P-interaction < 0.05). In the HF/LF+RO group, the plasma CRP concentration was lower than in the HF/LF group (88.1 vs. 765 pg/mL; P ≤ 0.05) and similar to that in the C and C+RO groups (158 and 128 pg/mL, respectively). CONCLUSION Dietary RO improves plasma lipid profile and liver functions and reduces low-grade systemic inflammation in rats; however, the extent of these beneficial effects is partly dependent on the diet type.