ABSTRACT
Objective@#To investigate the inhibitory effects and mechanism of Triticum aestivum (TA) on anaphylaxis in ovalbumin (OVA)-sensitized mice.@*Methods@#Twenty-five female BALB/c mice were randomly divided into five groups (n=5), including control group, OVA group, 100 mg/kg TA group, 200 mg/kg TA group and DEX (dexamethasone) group. OVA (20 μg) and aluminum hydroxide (1 mg) were dissolved in 100 μl of PBS solution and injected into the abdominal cavity of each experimental mouse, while the mice in the control group were injected with 100 μl of 0.9% normal saline. All mice were given drinking water. The above processes were repeated two weeks later, and different concentrations of experimental drugs were diluted in 1% CMC (carboxymethyl cellulose) solution to feed mice. Allergic symptoms and behaviors of each mouse were scored in the process of feeding. On the 12th day after first sensitization, mice in the control and experimental groups were subcutaneously injected in the auricle with 20 μl of 0.9% saline solution and OVA, respectively. The thickness of each mouse′s auricle was measured 6 and 24 hours later. Histopathologic changes in auricle tissues were observed by hematoxylin-eosin(HE) staining 24 hours later. The mice were euthanized by cervical dislocation in the 6th week after first sensitization. Abdominal aorta serum samples were collected and tested for specific inflammatory cytokines (IgE, IgG1, TNF-α, IL-4) and anti-OVA antibodies (IgE, IgG1) by ELISA. ELISA and RT-PCR were used to detect the expression of IFN-γ, IL-4, IL-5, IL-12 and IL-13 after spleen lymphocytes were stimulated with different concentrations of drugs.@*Results@#Both the score of allergic symptoms and behavior and the thickness of the auricle of the OVA group were the highest among all groups (P<0.05). A TA dose-dependent decrease was found in both of the two parameters, which was confirmed by histopathological analysis. ELISA results showed that the plasma levels of IgE, IgG1, IL-4 and TNF-α in the experimental groups were significantly higher than those in the control group, but all of them were decreased in a TA dose-dependent manner. TA at the high concentration of 200 mg/kg was similar to DEX in inhibiting the expression of IgE and TNF-α. RT-PCR results showed that Th1 cytokines (IFN-y and IL-12) in the experimental groups increased significantly as compared with those in the control group (P<0.05). Expression of IFN-y and IL-12 was not significantly affected by TA at various concentrations, but markedly inhibited by DEX. The levels of Th2 cytokines (IL-4, IL-5 and IL-13) in the experiment groups were significantly higher than those in the control group (P<0.05). Compared with the OVA group, the levels of IL-4, IL-5 and IL-13 were significantly reduced in TA groups, especially in the TA 100 μg/ml group in which the expression of the three cytokines was decreased by about 60%, 18% and 20%, respectively.@*Conclusion@#TA helps to maintain immune balance by selectively inhibiting the expression of Th2 cytokines (IL-4, IL-5, IL-13), IgE and IgG and not influencing Th1 cytokines (IFN-γ and IL-12). It has an anti-allergic effect as it effectively suppresses allergic responses. This research provides both theoretical and experimental basis for further development of novel anti-anaphylactic treatment with TA.