Title:Αlpha-2 Adrenergic and Opioids Receptors Participation in Mice Gastroprotection of Abelmoschus esculentus Lectin
Volume: 22
Issue: 30
Author(s): Kátia A. Ribeiro, Hellíada V. Chaves, Samuel Mateus Pereira Filho, Isabela Ribeiro Pinto, Dina Andressa Martins Monteiro, Samuel Oliveira Matos, Tatiane Santi-Gadelha, Carlos Alberto de Almeida Gadelha, José Thalles Jocelino Gomes de Lacerda, Lissiana M. V. Aguiar, Karuza M. A. Pereira, Norma M. B. Benevides, Vicente de Paulo T. Pinto, Gerardo Cristino Filho, Mirna M. Bezerra and Antonio A. R. Silva
Affiliation:
Keywords:
Abelmoschus esculentus lectin, ethanol-induced gastropathy, antioxidant activity.
Abstract: Lectins are a heterogeneous group of proteins and glycoproteins with potential
role as therapeutic and diagnostic tools to combat various diseases, besides some functions
on human organism. Abelmoschus esculentus (Okra), a horticultural plant of African origin,
is cultivated in northeastern Brazil, and used for different medicinal purposes. This work is
aimed to elucidate the action mechanisms of Abelmoschus esculentus lectin (AEL) gastro
protective effect on gastropathy induced by ethanol. Fasted mice treated with Ethanol 99.9%
(0.2 ml/animal, p.o.) received previously AEL (0.01, 0.1, 1.0, 10 or 50 mg/kg, i.v.), saline (5
ml/kg; i.v.) or ranitidine (80 mg/kg, p.o.) in four experimental series, in which pharmacological
tools (yohimbine, naloxone, L-NAME or indomethacin), were administered with the
purpose of make clear possible molecular action mechanisms. Mice were euthanized 30 min
after ethanol challenge to verify the stomach damages. Establishment of gastric oxidative
stress, tissue hemoglobin (Hb) content and microscopic features (H&E) were taken in order
to characterize the AEL gastro protective effect. AEL (1 mg/kg) was capable of protect mucosa against ethanol
damages in presence of two (L-NAME and indomethacin) of four antagonists/inhibitors used. The AEL effect
was reversed by naloxone and yohimbine, showing the involvement of opioids and Αlpha-2 adrenergic receptors
on gastric protective effect of this lectin. Evaluation of microscopic features, oxidative stress, and Hb levels
pointed the protective effects of AEL. This activity seems to be mediated by alpha-2 adrenergic and opioid receptors
activation. Nitric oxide or prostaglandins were not involved. AEL simultaneously showed antioxidant effect
that is probably implicated in its intricate defensive mechanism of action.
