Effects Of Aqueous Extracts From Lycopsis Orientalis Linn On Skin Ulcer And Its Mechanisms In Mice

Background and objectives:Chronic skin ulcer,which is a common treatment-resistant disease with the characteristics of refractoriness and longer course,mainly result from trauma,local dysaemia and infection,etc.With the improvement of living standard and the increase of the aging population,the prevelance of diabetic ulcers and lower extremity venous ulcer is also being rising trendacy.Chronic skin ulcers bring not only physical and mental suffering to the patients,but also heavy financial burden to social and family.Inflammation plays an important role in the process of the occurrence and agglutination of surface ulcers,which has marked effect on damage protraction and recovery of local ulcers.However,the commonly used anti-inflammatory drugs and antibiotics present no significant influence on the disorder status of the cytokine expression,which resulting in the limited curative effect of antibiotics to choronic ulcers.Natural plants and traditional Chinese medicine is the dominant field in the research and development of new drug in our country.Lycopsis orientalis Linn is a folk recipe and has good therapeutic effects on scytitis disease,but there is still no systematic study about its pharmacodynamics and mechanisms.Therefore,based on the aqueous extracts from Lycopsis orientalis Linn(AELO),we preformed the present study to explore the the effect of anti-skin ulcer and its mechanism from protein and mRNA levels,and ultimately to supply the experimental data and theories about the exploration of novel anti-chronic skin ulcer drug,especially the Lycopsis orientalis Linn.Methods:AELO was prepared with decocting method.The curative effect of AELO on skin ulcers,the PGE₂ content in ulcer tissue with spectrophotometric method,serum levels of IL-1β,IL-6 and TNF-αwith ELISA were detected in mice skin ulcer model induce by acetic acid chemical stimulus.The capillary permeability was measured with spectrophotometric method in mice acute peritonitis model.With the hot plate experiment and writhing essay,the effect of AELO on the alteration of pain threshold was observed. The expresses of cyclooxygenase(COX)-2 protein and mRNA in skin ulcer tissue were detected in mice skin ulcer tissue with Western blotting and RT-PCR method,respectively The bacteriostasis effect was evaluated using desk diffusion method and drug paper test.Results:1) Compared with the control group,the score of healing skin ulcer in AELO groups at the 3rd day increased but not significantly,while the score at the 5th and 7th day increased markedly.The contents of PGE2 in theraputic groups decreased to 57.6%,66.4%,46.1%of the control level on the 3rd,5th and 7th day after the administration of AELO respectively.2) AELO(10-40g/kg) treatment increased the pain threshold and decreased the number of writhing.In the model of acute peritonitis,the level of Evans blue effusion in peritonitis group was higher than that in control group.Capillary permeability in AELO treatment groups decreased significantly compared with peritonitis group.3) After 6 hours after acetic acid injection,the serum levels of IL-1β,IL-6 and TNF-αin AELO treatment groups(10-40g/kg) were significantly lower than that in peritonitis group(p＜0.05).The decreasing degree was markedly positive correlation with the dose of AELO.4) The expressions of COX-2 and its mRNA obviously increased in skin ulcer tissue. Nevertheless,after the administration of AELO,the expressions decreased significantly.5) The bacteriostasis test drug paper test showed that AELO presented preferable inhibitory effect on Esccherichia coli,Staphylococcus aureus and Enterococcus faecalis,but not onβ-hemolytic streptococcus.Conelution:1.The local administration of AELO can significantly promote the healing of skin ulcer.2 The administration of AELO presented the noticeable effect of relieving pain, degrading the capillary permeability during infection,decreasing the serum level of IL-1β, IL-6 and TNF-αand down regulating the expression of COX-2 protein and mRNA,as well as decreasing the level of PGE₂ in ulcer tissue.3.AELO showed preferably inhibitory effect on Esccherichia coli,Staphylococcus aureus and Enterococcus faecalis in vitro.