Study On Protective Effects Of Taraxasterol On Asthma And Endotoxemia In Mice

Asthma and endotoxemia is a serious threat to public health at present. Asthma is a chronic inflammatory disease of the airways, which is involved in variety of inflammatory cells. Endotoxemia is systemic inflammatory response syndrome caused by infection. The methods of prevention and treatment have been a hot topic in today’s medical research. Taraxasterol is one of the active ingredients of dandelion. It suggests that taraxasterol has protective effect on asthma and endotoxemia in mice, and provide a theoretical basis for clinical application and further development and utilization.Model of asthma was established by OVA. The mice were divided into model group, taraxasterol groups (2.5,5and10mg/kg) and posotive group (dexamethasone2mg/kg). The pathological changes in lung tissue of mice were observed, the level of inflammatory cell and cytokine interleukin-4(IL-4), IL-5and IL-13release in bronchoalveolar lavage fluid (BALF) were measured, and anti-OVA specific IgE in serum was detected. Protective effect of taraxasterol on OVA-induced asthma in mice was evaluated. Model of endotoxemia were established by LPS. Protective effect of taraxasterol on endotoxemic mice from prevention and treatment was studied. Mice are randomly divided into control group, taraxasterol group, taraxasterol+LPS group (10mg/kg) and model group. Pathological changes of lung tissue in mice were detected. TNp-α, IL-β, IL-6and PGE2in serum were measured by ELISA and NO was measured by Griess reagent at different time points to explore the protective effect and mechanism.Results:Taraxasterol could decrease pathological changes of lung tissues in asthma mice compared with the model group, the degree of inflammatory response was significantly lower. The number of inflammatory cells counts in BALF were significantly reduced (P<0.05or P<0.01). Taraxasterol decreased the secretion of IL-4, IL-5and IL-13in BALF, which showed significantly difference (P<0.05or P<0.01). The content of anti-OVA specific IgE expression was also significantly inhibited in asthma mice (P<0.01). Compared with model group, taraxasterol has effect of prevention and protection on endotoxemic mice. Taraxasterol decreased pathological changes of lung tissue in endotoxemic mice of taraxasterol+LPS group. The level of TNF-α,IL-1β, IL-6, PGE2and NO expression were significantly inhibited within24h after stimulation with LPS (P<0.05or P<0.01).Conclusion:Taraxasterol could inhibit the secretion of IL-4, IL-5, IL-13and anti-OVA specific IgE of OVA-induced asthmatic mice, decrease lung tissue injury, reduce level of mucus secretion. It suggests that taraxasterol has protective effect on asthmatic mice; Taraxasterol could decrease levels of IL-1β, IL-6, IFN-γ, NO and PGE2secretion in serum of LPS-induced endotoxemic mice and reduce degree of inflammatory cell infiltration and lung hemorrhage, it showed that taraxasterol plays a protective role in endotoxemic mice. It suggests taraxasterol can effectively prevent the occurrence and development of asthma and endotoxemia.