title: Reciprocal regulation of endothelial nitric-oxide synthase and NADPH oxidase by betulinic acid in human endothelial cells.
abstract: Nitric oxide (NO) produced by endothelial NO synthase (eNOS) is a protective principle in the vasculature. Many cardiovascular diseases are associated with reduced NO bioactivity and eNOS uncoupling due to oxidative stress. Compounds that reverse eNOS uncoupling and increase eNOS expression are of therapeutic interest. Zizyphi Spinosi semen (ZSS) is one of the most widely used traditional Chinese herbs with protective effects on the cardiovascular system. In human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells, an extract of ZSS increased eNOS promoter activity, eNOS mRNA and protein expression, and NO production in a concentration- and time-dependent manner. Major ZSS constituents include saponins, such as jujuboside A and B, and pentacyclic triterpenes, such as betulin and betulinic acid. Jujuboside A, jujuboside B, or betulin had no significant effect on eNOS expression, whereas betulinic acid increased eNOS mRNA and protein expression in HUVEC and EA.hy 926 cells. Interestingly, betulinic acid also attenuated the expression of NADPH oxidase subunits Nox4 and p22phox, thereby reducing oxidative stress and improving eNOS function. Consequently, betulinic acid-treated endothelial cells showed an increased production of bioactive NO (as indicated by a higher efficacy in stimulating cGMP generation in RFL-6 reporter cells). Thus, betulinic acid possesses combined properties of eNOS up-regulation and NADPH oxidase down-regulation. Compounds such as betulinic acid may have a therapeutic potential in cardiovascular disease.
authors.affiliation: Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Steinkamp-Fenske
authors.forename: Larissa
authors.initials: L
authors.lastname: Bollinger
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Ying
authors.initials: Y
authors.lastname: Yao
authors.forename: Sven
authors.initials: S
authors.lastname: Horke
authors.forename: Ulrich
authors.initials: U
authors.lastname: Förstermann
authors.forename: Huige
authors.initials: H
authors.lastname: Li
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D053978:Pentacyclic Triterpenes; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012503:Saponins / Q000494:pharmacology; D013096:Spermine / Q000031:analogs & derivatives / Q000494:pharmacology; D014315:Triterpenes / Q000494:pharmacology*; D031957:Ziziphus / Q000737:chemistry; D000094062:Betulinic Acid
chemical_list: D000098:Acetophenones; D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D053978:Pentacyclic Triterpenes; D017382:Reactive Oxygen Species; D012503:Saponins; D014315:Triterpenes; C091861:spermine nitric oxide complex; D013096:Spermine; D009569:Nitric Oxide; C087808:jujuboside A; C002503:betulin; C056165:acetovanillone; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; C086986:CYBA protein, human; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester; D000094062:Betulinic Acid