title: Antioxidant and anti-inflammatory activities contribute to the prophylactic effect of semi-purified fractions obtained from the crude methanol extract of Muntingia calabura leaves against gastric ulceration in rats.
abstract: BACKGROUND
  In traditional medicine, the leaves, flowers, barks and roots of Muntingia calabura L. (Muntingiaceae) have been employed as a treatment for various ailments including dyspepsia and to relieve pain caused by gastritis and peptic ulcer disease. The methanolic extract of Muntingia calabura leaves (MEMC) has been proven in the previous study to possess significant antiulcer activity. In this study, we attempted to determine the prophylactic effect of the fractions obtained from MEMC against ethanol-induced gastric lesion in rats and the involvement of antioxidants and anti-inflammatory mediators.
  
  
  METHODS
  The MEMC was fractionated with petroleum ether (PEF), ethyl acetate (EAF) and distilled water (AQF). These fractions were investigated for possible antiulcer property using ethanol-induced gastric ulcer rat model. The rats were administered orally once daily with 8% Tween 80 (control), 100mg/kg ranitidine, or the fractions, in the doses of 100, 250, and 500 mg/kg, for 7 days, followed by ulcer induction using absolute ethanol. The rats were euthanized; macroscopic and histological observations of the stomach were done. The ulcer area (UA) was determined and the percentage protection afforded by the fractions was calculated. The fractions were subjected to antioxidant studies including the superoxide and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, oxygen radical absorbance capacity (ORAC) and total phenolic content (TPC) assay. Involvement of nitric oxide (NO) and inflammatory mediators such as lipoxygenase (LOX) and xanthine oxidase (XO) were evaluated. Phytochemical screening and HPLC analysis of the fractions were also conducted.
  
  
  RESULTS
  Pre-treatment of PEF and EAF significantly (p<0.001) attenuated the gastric lesions as compared to the control group in a dose-dependent manner. On the other hand, 100 and 250 mg/kg of AQF significantly (p<0.001) prevented the ulcer formation but at the highest dose (500 mg/kg), AQF failed to significantly reduce the ulcer formation, showing a dose-independent antiulcerative effect of AQF. The histological evaluation supported the observed gastroprotective activity of PEF, EAF and AQF. All the fractions showed high superoxide and DPPH scavenging activity, meanwhile the EAF showed highest TPC followed by PEF and AQF. These fractions also significantly (p<0.05) inhibited the NO while maintaining the viability of the cells. EAF exhibited high inhibition towards both the LOX and XO enzymes, meanwhile PEF and AQF exerted high LOX inhibition but low XO inhibition. Phytochemical screening and HPLC profiling suggested the presence of flavonoid- and tannin based compounds in PEF and EAF.
  
  
  CONCLUSIONS
  It can be concluded that the prophylactic effect of the fractions on gastric ulceration in rats is associated with its high antioxidant activity and its ability to effectively inhibit the inflammation mediators. Presence of several flavonoids and gallic acid explains the effectiveness of the fractions in affording protection against gastric damages.
authors.affiliation: Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, 43400 Serdang, Malaysia.
authors.forename: Tavamani
authors.initials: T
authors.lastname: Balan
authors.affiliation: Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, 43400 Serdang, Malaysia.
authors.forename: Mohd Hijaz Mohd
authors.initials: MH
authors.lastname: Sani
authors.affiliation: Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, 43400 Serdang, Malaysia.
authors.forename: Salahuddin Haji
authors.initials: SH
authors.lastname: Mumtaz Ahmad
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University, 57000 Kuala Lumpur, Malaysia.
authors.forename: Velan
authors.initials: V
authors.lastname: Suppaiah
authors.affiliation: Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, 43400 Serdang, Malaysia.
authors.forename: Norhafizah
authors.initials: N
authors.lastname: Mohtarrudin
authors.affiliation: Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, 43400 Serdang, Malaysia. Electronic address: dr_zaz@yahoo.com.
authors.forename: Zainul Amiruddin
authors.initials: ZA
authors.lastname: Zakaria
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D000897:Anti-Ulcer Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000737:chemistry; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D000431:Ethanol; D019684:Magnoliopsida; D008297:Male; D000432:Methanol / Q000737:chemistry; D051379:Mice; D009573:Nitrites / Q000378:metabolism; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves; D017207:Rats, Sprague-Dawley; D012997:Solvents / Q000737:chemistry; D013276:Stomach Ulcer / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D013481:Superoxides / Q000737:chemistry; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D000897:Anti-Ulcer Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D009573:Nitrites; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D013481:Superoxides; D000431:Ethanol; C004931:1,1-diphenyl-2-picrylhydrazyl; D014969:Xanthine Oxidase; D000432:Methanol
keywords: Anti-inflammation; Antioxidant; Flavonoids; Gallic acid; Gastric ulcer; Muntingia calabura