Gastroprotective effect of (-)-myrtenol against ethanol-induced acute gastric lesions: possible mechanisms

J Pharm Pharmacol. 2016 Aug;68(8):1085-92. doi: 10.1111/jphp.12583. Epub 2016 Jun 12.

Abstract

Objectives: (-)-Myrtenol is a natural fragrance monoterpenoid structurally related to α-pinene found in diverse plant essential oils. This study was aimed to assess the anti-ulcerogenic potential of (-)-myrtenol against ethanol-induced gastric lesions and to elucidate the underlying mechanism(s).

Methods: Gastroprotective activity of (-)-myrtenol was evaluated using the mouse model of ethanol-induced gastric damage. To elucidate the gastroprotective mechanism(s), the roles of GABA, prostaglandins, nitric oxide and KATP channels were assessed. Besides, the oxidative stress-related parameters and the mucus content in gastric tissues were analysed.

Key findings: (-)-Myrtenol at oral doses of 25, 50 and 100 mg/kg significantly decreased the severity of ethanol-induced gastric lesions affording gastroprotection that was accompanied by a decrease in the activity of myeloperoxidase and malondialdehyde, an increase in GPx, SOD, and catalase activity in gastric tissues, and with well-maintained normal levels of nitrite/nitrate, gastric mucus and NP-SHs. Pretreatment with GABA-A receptor antagonist flumazenil, the COX inhibitor indomethacin, and NO synthesis inhibitor L-NAME but not with KATP channel blocker glibenclamide significantly blocked the (-)-myrtenol gastroprotection.

Conclusion: These results provide first-time evidence for the gastroprotective effect of (-)-myrtenol that could be related to GABAA -receptor activation and antioxidant activity.

Keywords: (-)-myrtenol; GABA-A receptor; antioxidant; essential oil; ethanol-induced gastric damage; gastroprotection.

MeSH terms

  • Animals
  • Anti-Ulcer Agents / pharmacology*
  • Anti-Ulcer Agents / therapeutic use
  • Antioxidants / metabolism
  • Antioxidants / pharmacology*
  • Antioxidants / therapeutic use
  • Bicyclic Monoterpenes
  • Gastric Mucosa / metabolism
  • Male
  • Mice
  • Monoterpenes / pharmacology*
  • Monoterpenes / therapeutic use
  • Mucus / metabolism
  • Myrtus / chemistry
  • Oils, Volatile / chemistry
  • Peroxidase / metabolism
  • Phytotherapy*
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use
  • Receptors, GABA-A / metabolism*
  • Stomach / drug effects*
  • Stomach / pathology
  • Stomach Ulcer / metabolism*
  • Stomach Ulcer / prevention & control
  • gamma-Aminobutyric Acid / metabolism

Substances

  • Anti-Ulcer Agents
  • Antioxidants
  • Bicyclic Monoterpenes
  • Monoterpenes
  • Oils, Volatile
  • Plant Extracts
  • Receptors, GABA-A
  • gamma-Aminobutyric Acid
  • Peroxidase
  • myrtenol