title: Involvement of nitric oxide in the gastroprotective effects of an aqueous extract of Pfaffia glomerata (Spreng) Pedersen, Amaranthaceae, in rats.
abstract: The plants belonging to Pfaffia genus are used in folk medicine to treat gastric disturbances. This study examined the effects of an aqueous extract of Pfaffia glomerata (Spreng) Pedersen (AEP) on the gastrointestinal tract. Wistar rats were pretreated orally (p.o.) with the AEP (125, 250, 500 and 1000 mg.kg(-1)) before induction of ulcers by hypothermic restraint stress (HRS, 3 h restraint stress at 4 degrees C), ethanol (ET, 70%; 0.5 ml/animal; p.o.) or indomethacin (IND, 20 mg.kg(-1); s.c.). Control animals received water (C) or ranitidine (60 mg.kg(-1)) p.o. The AEP protected rats against HRS and ET-induced ulcers, but was not able to protect the gastric mucosa against IND-induced ulcers. When injected into the duodenal lumen, the AEP reduced total acidity and both basal and histamine-stimulated acid secretion in pylorus-ligated rats. In addition, gastric secretion from AEP-treated animals exhibited increased concentrations of nitrite and nitrate. Treatment of animals with L-NAME (120 mg.kg(-1), p.o.) prevented both the reduction of total acidity and the increase in NOx levels promoted by AEP treatment. In conclusion, AEP effectively protected the gastric mucosa and inhibited gastric acid secretion in rats, probably by involving the histaminergic pathway and an enhanced production of nitric oxide in the stomach.
authors.affiliation: Department of Pharmacology, Sector of Biological Sciences, Universidade Federal do Paraná, Centro Politécnico, CP 19031, 81531-990, Curitiba, PR, Brazil.
authors.forename: Cristina Setim
authors.initials: CS
authors.lastname: Freitas
authors.forename: Cristiane Hatsuko
authors.initials: CH
authors.lastname: Baggio
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Da Silva-Santos
authors.forename: Lia
authors.initials: L
authors.lastname: Rieck
authors.forename: Cid Aimbiré
authors.initials: CA
authors.lastname: de Moraes Santos
authors.forename: Cirino Corrêa
authors.initials: CC
authors.lastname: Júnior
authors.forename: Lin Chau
authors.initials: LC
authors.lastname: Ming
authors.forename: Diógenes Aparício
authors.initials: DA
authors.lastname: Garcia Cortez
authors.forename: Maria Consuelo Andrade
authors.initials: MC
authors.lastname: Marques
mesh_terms: D027703:Amaranthaceae; D000818:Animals; D001938:Brazil; D004381:Duodenal Ulcer / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D005745:Gastric Acidity Determination; D007036:Hypothermia, Induced; D007213:Indomethacin; D019331:NG-Nitroarginine Methyl Ester / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010936:Plant Extracts / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000150:complications
chemical_list: D010936:Plant Extracts; D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin