Protective effect of dietary perilla oil on allergic inflammation in asthmatic mice

Perilla oil (PER) is rich in a-linolenic acid (n-3 fatty acid). To unravel the effects of dietary PER on allergic asthmatic inflammation, three kinds of dietary oil, including PER, corn oil (COR), and perilla compound oil (50% PER and 50% COR), were used for replacing the oil in an AIN76 feed consumed by ovalbumin (OVA)-sensitized and challenged mice continuously for 5?wk. T-helper type 1 lymphocyte (Th1)/T-helper type 2 lymphocyte (Th2) and pro-/anti-inflammatory cytokines secreted by the cells from the airway, the lungs, and the spleen of experimental mice were determined by ELISA. The results showed that dietary PER inhibited interleukin (IL)-1 beta and tumor necrosis factor (TNF)-a secretions by lipopolysaccharide (LPS)-stimulated lung cells, as well as interferon (IFN)-? and IL-6 secretions by LPS-stimulated splenocytes. Perilla compound oil increased the secretion ratio of IFN-?/IL-5 (Th1/Th2 cytokines) in LPS-stimulated bronchoalveolar lavage fluid cells, but decreased the ratio of IL-6/IL-10 (pro-/anti-inflammatory cytokines) in LPS-stimulated splenocytes. The present study demonstrated that dietary PER and its compound oil protected the airways, the lungs, and the spleen from allergic inflammation in OVA-challenged asthmatic mice, suggesting that an appropriate n-6/n-3 fatty acid ratio at a ratio of 1:1 or less in dietary oil may be beneficial to improve the Th2-skewed allergic asthmatic inflammation. Practical applications: The present study demonstrated that dietary PER and its compound oil protected the airways, the lungs, and the spleen from allergic inflammation in OVA-challenged asthmatic mice, suggesting that an appropriate n-6/n-3 fatty acid ratio at a ratio of 1:1 or less in dietary oil may be beneficial to improve the Th2-skewed allergic asthmatic inflammation.