Melatonin decreases the expression of connective tissue growth factor and inhibite airway remodeling in asthmatic mouse

Objective To explore the effect of melatonin(MT) on connective tissue growth factor(CTGF) and the airway remodeling in asthmatic mice.Methods The mice were randomly divided into 4 groups as control group,asthmatic group,MT treated group and dexamethasone treated group.The mice were sensitized and repeatedly challenged with ovalbumin(OVA) for 2 and 4 weeks.MT treated group were intraperitoneal injected with MT,and dexamethasone treated group were intraperitoneal injected with DXM.The eosinophils around the airway were examined with microscopy after histochemical staining.Masson staining was used to stain collagen fibers and PAS staining was used to stain airway mucus.The following parameters including the perimeter of bronchial basement membrane(Pbm),total bronchial wall area(WAt),inner wall area(WAi),smooth muscle area(WAm),collagen area(Wcol)and mucus area were measured by Leica image analysis software.The protein expression of CTGF was assessed with immunohistochemistry.Results WAt/Pbm,WAi/Pbm,WAm/Pbm,Wcol/Pbm,the mucus area and the expression of CTGF were significantly higher in asthmatic group than those in control group.MT treated group and dexamethasone treated group significantly alleviated the above-mentioned indicators increased.Conclusion MT inhibitsthe expression of CTGF and airway remodeling,which has a comparative potency of dexamethasone.