| Ulcerative colitis is a kind of chronic inflammatory bowel disease. Because of its unknown etiology and lack of specific curative treatments, ulcerative colitis and cancer, cardiovascular disease were considered as the most difficult curable disease of the world. Treating Ulcerative colitis while limiting drug-induced toxicity is continues challenge. So there is pressing need for developing effective therapeutic approach with low toxicity. Acalypha australis L, as Chinese herbal medicine, was commonly used for treating chronic diarrhea and patients suffered from the chronic diarrhea often get surprised therapeutic effect after treated with Acalypha australis L. However, the research literatures on Acalypha australis L are few. So it is necessary to evaluate the activity of this herb on ulcerative colitis and find out its mechanism as well as the active constituents.First of all, SASP was used as the standard drug for comparison. We evaluate the effect of Acalypha decoction in different doses on TNBS- induced experimental ulcerative colitis in rats. TNBS (2,4,6-trinitrobenzene sulfonic acid)-induced ulcerative colitis model resembles human ulcerative colitis in many areas and now was widely used for screening the anti-colitis agent. The degree of dirrhea and bloody stool, weight loss, colon macroscopic score and histological change, myeloperoxidase (MPO) activity were focal study points after the colitis was succefully induced in rats by TNBS and after the model rats were treated (i.g) with Acalyph decoction. It demonstrated that both doses(6.5,9.5g/kg) of Acalyph decoction can effectively improved the symptom of TNBS-induced UC rats and have the comparable effect with SASP(P>0.05).Though the exactly etiology of ulcerative colitis is still not clear but active oxygen and NO have been sure to participate in the process of pathogenesis. Weexamined the effect of Acalypha decoction on the active oxygen and NO production and found that Acalypha decoction treatment can significantly elevate the activity of SOD and GSH-PX which were decreased in TNBS-indcuced model rats colon tissue and decreased the level of MDA, NO and iNOS which were increased in TNBS model rats(P<0.05). So Acalypha australis L can protect colon tissue from the active oxygen and NO damage through elevating the activity of SOD and GSH-PX and suppressing the production of NO.Using RT-PCR method, we studied the expression of iNOS mRNA in normal rats, UC model rats and UC model rats treated with Acaphaly decoction. The study demonstrated that in normal colon there is no expression of iNOS mRNA while in UC model colon there is stronger expression. In Acaphaly decoction treated UC model colon, there is also expression of iNOS mRNA but significantly weaker than untreated UC model group (P<0.05). We can say Acaphaly decoction can suppress the expression of iNOS mRNA. Decreasing the production of NO by suppressing the expression of iNOS mRNA is involved in the mechanism of Acaphaly australis L anti-colitis effect.To find out what is the active constitunents in Acalypha australis L that is of anti-colitis effect, we studied the effect of four different polar part of Acalypha decoction (p.e extract part, EtOAC extract part, n-butanol extract part and water part) on TNBS-induced UC model rats. EtOAC extract part has the most effective effect on UC model rats. By many kinds of separation methods we got four compounds from EtOAC extract part of Acalypha decoction. Their structures were elucidated based on spectra data (1H-NMR, 13C-NMR, DEPT, EI-MS, ESI-MS, IR). They were: C-2-1: 4-Hydroxybenzoic acid methyl ester; C-2-2: 3-methoxy-4-hydroxybenzoic acid; C-2-3: protocatechuic acid; C-2-4: salicylic acid. This four compounds are all firstly separated from Acalypha australis L.We studied the inhibitory effect of four compounds on NO production in LPS stimulated murine macrophage like cellline RAW264.7 cell. We also tested the effect of four compounds on cell viability in different concentration by MTT method. All the...
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