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


RESULTS
(-)-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.


CONCLUSIONS
These results provide first-time evidence for the gastroprotective effect of (-)-myrtenol that could be related to GABAA -receptor activation and antioxidant activity.
Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.|Medicinal Plants Research Center, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil.
Ana Flávia Seraine Custódio
AF
Viana
Medicinal Plants Research Center, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil.
Francilene Vieira
FV
da Silva
Medicinal Plants Research Center, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil.
Hélio de Barros
Hde B
Fernandes
Medicinal Plants Research Center, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil.
Irisdalva Sousa
IS
Oliveira
Postgraduate Program in Biotechnology, Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Odontology and Nursing, Federal University of the Ceará, Fortaleza, Ceará, Brazil.
Milena Aguiar
MA
Braga
Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Paulo Iury Gomes
PI
Nunes
Laboratory of Pathology and Legal Medicine, Faculty of Veterinary Science, State University of Ceará, Fortaleza, Ceará, Brazil.
Daniel de Araújo
Dde A
Viana
Department of Pharmaceutical Sciences, Federal University of Paraiba, João Pessoa, Paraiba, Brazil.
Damião Pergentino
DP
de Sousa
Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Vietla Satyanarayana
VS
Rao
Medicinal Plants Research Center, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil.
Rita de Cássia Meneses
Rde C
Oliveira
Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Flávia
F
Almeida Santos
D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D000081008:Bicyclic Monoterpenes; D005753:Gastric Mucosa / Q000378:metabolism; D008297:Male; D051379:Mice; D039821:Monoterpenes / Q000494:pharmacology* / Q000627:therapeutic use; D009093:Mucus / Q000378:metabolism; D031651:Myrtus / Q000737:chemistry; D009822:Oils, Volatile / Q000737:chemistry; D009195:Peroxidase / Q000378:metabolism; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D011963:Receptors, GABA-A / Q000378:metabolism*; D013270:Stomach / Q000187:drug effects* / Q000473:pathology; D013276:Stomach Ulcer / Q000378:metabolism* / Q000517:prevention & control; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D000897:Anti-Ulcer Agents; D000975:Antioxidants; D000081008:Bicyclic Monoterpenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010936:Plant Extracts; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid; D009195:Peroxidase; C534317:myrtenol
(-)-myrtenol; GABA-A receptor; antioxidant; essential oil; ethanol-induced gastric damage; gastroprotection