Dietary perilla oil lowers serum lipids and ovalbumin-specific IgG1, but increases total IgE levels in ovalbumin-challenged mice

Abstract

Our previous studies indicated that α-linolenic acid (ALA)-rich perilla oil might alleviate bronchoalveolar inflammation. However, it failed to modulate the Th1/Th2 balance toward the Th1 pole during Th2-skewed allergic airway inflammation in mice. This study attempts to further investigate the effects of dietary perilla oil on serum lipids and immunoglobulin profiles using an ovalbumin (OVA)-challenged mouse model. The inbred female BALB/c mice were randomly divided into four groups and fed different AIN-76 feeds containing 5% corn oil (rich in linoleic acid, 18:2n-6 polyunsaturated fatty acids (PUFA), as a control diet), 5% perilla oil (rich in α-linolenic acid, 18:3n-3 PUFA) or 5% compound oil containing 50% corn oil and 50% perilla oil, respectively, for 35 consecutive days ad libitum. Experimental mice were sensitized by an intraperitoneal injection of alum-precipitated antigen containing ovalbumin on 7, 14 and 21 days after supply of the specified experimental diets. One week later, the mice were then challenged by aerosolized OVA. The results showed that dietary perilla oil administration significantly ( P < 0.05) decreased the relative liver tissue weight (RTW) and serum lipid levels including triglycerides, total cholesterol, HDL- and LDL-cholesterol. However, the HDL/LDL ratio was also significantly lowered by dietary perilla oil. Dietary perilla oil markedly decreased serum OVA-specific IgG1 level and total IgA antibodies (Th2 antibodies). Unfortunately, it also increased non-specific serum IgE (Th2 antibody) levels. The results suggest that dietary perilla oil might have a moderately beneficial effect on asthmatic allergy via lowering serum lipids and OVA-specific IgG1, as well as total IgA levels. However, it failed to obviously modulate Th1/Th2 antibody levels via isotype switching of B cells from Th2 antibody to Th1 antibody.