Abstract: To explore the therapeutic effect and mechanism of Coleus Forskohlii extract (CFE) on asthma,the rat asthma model was established by ovalbumin (OVA) combined with adjuvant aluminum hydroxide.Sixty SPF-SD male rats were divided into blank group,model group,dexamethasone group,CFE high-dose group (12.8 g/kg) and CFE low-dose group (64 g/kg),normal saline,dexamethasone and CFE were administered to the stomach once a day for 14 days consecutively in groups,with a gavage volume of 1 mL/100 g.HE staining was used to observe the histopathological changes of lung;ELISA was used to detect the expression of IFN-γ,IL-4 and IL-17A;Western blot assay was used to detect expression of related MAPK pathway protein.Compared with the model group,HE results showed that the high and low dose groups of CFE could significantly reduce the pathological damage of the lung tissue after OVA stimulation,with clear airway contour and significantly reduced epithelial cell shedding;ELISA results showed that the levels of IL-4 and IL-17A in serum and BALF of rats in the high and low dose CFE groups decreased,while the level of IFN-γ increased,with statistically significant differences (P < 0.05 or P < 0.01);WB results showed that the high dose group of CFE reduced significantly the expression of p-ERK、p-JNK and p-p38 proteins in rats lung tissues (P < 0.05 or P < 0.01).To sum up,Coleus Forskohlii extract can effectively alleviate the airway inflammation induced by OVA in rats with asthma,and the mechanism is related to the regulation of MAPK signaling pathway.

Key words: Coleus forskohlii, asthma, inflammation, MAPK signaling pathway