Protective Effect And Mechanisms Of Portulaca Oleracea L. On Experimental Enteritis In Rats

Portulaca Oleracea L.is a widely distributed Chinese medicine and also a vegetable.In Traditional Chinese medicine(TCM),its property is classified as cold,with the effect of clearing heat and eliminating damp.P.Oleracea L.is commonly used to treat inflammatory diseases such as Diarrhea,hemafecia,abscess,psoriasis and so on.Enteritis is a common disease in animal husbandry and pet clinic,which seriously affects the economic benefits and the quality of life of pets and their owners.In this study,two kinds of models of rat enteritis were made to explore the therapeutic effect of aqueous extract of P.Oleracea L.(PO)on enteritis.The anti-inflammatory effects and molecular mechanisms of PO,quercetin(QUE)and kaempferol(KAE),the main components of PO,were investigated by using rat intestinal microvascular cells(RIMVECs)and rat intestinal epithelial cells(IEC-6)as the cell model.Animal testMethods:Sprague-dawley rats were divided into five groups,namely,the control group,the model group,the high(10 g/Kg)/middle(7.5 g/Kg)/low(5 g/Kg)concentration drug group.The drug group was given the corresponding aqueous extract of PO by gavage administration every day.A rat model of infectious/non-infectious enteritis was established by intraperitoneal injection of lipopolysaccharide(LPS)and freely drink of dextran sulfate(DSS),respectively.The efficacy of PO was evaluated by observing the condition of rats,disease activity index and state of intestinal tract.Myeloperoxidase(MPO)level was detected by MPO detection kit.The level of inflammatory factors(TNF-a,IL-1β and IL-6)was detected by ELISA kit.Inflammation-related proteins in the intestine tissue was valued by Western blot and immunohistochemistry methods.Results and conclusion:The results showed that the PO has a protective effect on both LPS and DSS induced enteritis rats.PO can significantly improve the health status of the rats,reduce the disease activity index(DAI)and alleviate the injury of intestinal villi.PO decreased the expression of MPO and inflammatory factors(TNF-a,IL-1β and IL-6)and inhibited the expression of TLR4 and NF-κB protein in intestinal tissue.It is indicated that PO has certain protective effect on infectious and non-infectious enteritis.Cell testMethods:RIMVECs of primitive culture and cell line IEC-6 were divided into five groups,namely,the control group,the model group,the high/middle/low concentration drugs(PO:100 μg/mL;10 μg/mL;1 μg/mL/QUE:80 μM;40 μM;20 μM/KAE:50 pM;25 μM;12.5 gM)group.RIMVECs and IEC-6 were pretreated with drugs of various concentrations followed by LPS stimulation.The effects of high concentration of LPS on cell activity and leaking of lactate dehydrogenase(LDH)were detected.ELISA examined protein levels of TNF-a,IL-1β,IL-6,IL-10,ICAM-1 and VCAM-1 in supernatant.Protein levels of TLR4,NF-κB,MAPK and STAT in cells were measured by western blot.Results and conclusion:PO can protect RIMVECs and IEC-6 from high concentration of LPS damage.PO also can inhibit the overexpression of TNF-a,IL-1β and IL-6.The effect of anti-inflammation is mediated by TLR4/NF-κB pathway.Quercetin and kaempferol effectively inhibit the damage of RIMVECs by high concentration of LPS and inhibit the overexpression of TNF-a,IL-1β,IL-6,ICAM-1 and VCAM-1 induced by low concentration LPS.The anti-inflammation effect of PO is via TLR4/NF-κB singnaling pathway.In addition,TLR4/NF-κB/MAPK/STAT pathway is involved in the anti-inflammatory effect of QUE/KAE.Conclusion:PO is effective in preventing infectious and non-infectious enteritis in rats.The anti-inflammatory effect of PO is achieved by regulating TLR4/NF-κB/MAPK/STAT.Quercetin and kaempferol are the main active ingredients of PO.