Studies On Chemical Components And Anti-Inflammatory Activity Of Apocynum Venetum L.

Background: Apocynum venetum L.,a plant of Apocynaceae family,is also used as a folk medicine for regulating blood pressure,relax the nervous system,protecting liver and promoting diuresis.Although its biochemical and physiological mechanisms are unclear,A.venetum L.has become a popular health product for improving human health in Asian and North American market.But its effects of improving gastrointestinal dysfunction,antiinflammatory and anti-hypertensive have attracted much attention.Methods: We isolated compounds from 95% ethanol extract of A.venetum L.leaf and purified by column chromatography,TLC,HPLC and other separation methods,and their chemistry structure was identified by UV,IR,MS and NMR.We detect the most effective compound by NO inhibition assay.We investigate anti-Inflammatory effects on dextran sulfate sodium(DSS)-induced colitis mice and lipopolysaccharide(LPS)-stimulated RAW264.7 cells.Results: We isolated 12 compounds from ethanol extract of A.venetum L.leaf,including lupeol,β-amyrin,β-sitosterol,betulin,betulinic acid,uvaol,cholesterol,dibutyl phthalate,methoxytocopherol,(2S)-2,3-O-dioctadeca-9Z,12 Z,15Z-trienoylglyceryl-O-β-Dgalactopyranoside,2(R)-1-O-octadecanoyl-2-O-(9Z,12 Z,15Z-octatrienoyl)-3-O-β-D–galactopyranosyl glycerol,2-a-linolenoylglycerol-1-O-b-D-galactopyranoside.Betulin,betulinic acid,uvaol,cholesterol,dibutyl phthalate,methoxytocopherol,and three galactolipids were first obtained in A.venetum L.We found uvaol has excellent potential of inhibiting NO production.Uvaol could significantly inhibit LPS-induced inflammatory mediators(IL-6,IL-1β,TNF-α and MCP-1)mRNA expression and production,effectively reducing iNOS,COX-2 production and phosphorylation of STAT3 and ERK.In DSS-induced colitis mice,uvaol can significantly reduce disease activity index(DAI),and reduce the shortening of the colon,colon tissue damage and the MPO activity.In addition,uvaol could significantly reduce the infiltration of macrophages and inflammatory mediators(TNF-α,IL-6,IL-1β and MCP-1)mRNA expression and production in colon tissue,while inhibiting the production of p-STAT3 and p-ERK.Conclusion: We isolated and purified 12 ompounds from Apocynum venetum L.leaves,nine of which were obtained for the first time,which enriched the chemical structure of A.venetum L.and laid a foundation for its material basic research;uvaol has potent anti-inflammatory effects on DSS-induced experimental colitis and LPS-stimulated RAW264.7 macrophage cells.These results provided a scientific basis for expand the new pharmacological effects of A.venetum L.and promote the synthesis of A.venetum L.