RESUMEN
BACKGROUND: Alpha-pinene (α-pinene) is a monoterpene commonly found in essential oils with gastroprotective activity obtained from diverse medicinal plants, including Hyptis species. The genus Hyptis (lamiaceae) consists of almost 400 species widespread in tropical and temperate regions of America. In the north and northeastern Brazil, some Hyptis species are used in traditional medicine to treat gastrointestinal disturbances. OBJECTIVE: The present study has investigated the gastoprotective effect of purified α-pinene in experimental gastric ulcer induced by ethanol and indomethacin in mice. MATERIALS AND METHODS: Gastric ulcers were induced in male Swiss mice (20-30 g) by oral administration of absolute ethanol or indomethacin 45 min after oral pretreatment with vehicle, standard control drugs or α-pinene (10, 30, and 100 mg/kg). One hour after the ulcerative challenges, the stomach were removed, and gastric lesions areas measured. The effects of α-pinene on the gastric juice acidity were determined by pylorus ligation model. The gastrointestinal motility and mucus depletion were determined by measuring the gastric levels of phenol red and alcian blue, respectively. Hematoxylin and eosin stained sections of gastric mucosa of the experimental groups were used for histology analysis. RESULTS: α-pinene pretreatment inhibited ethanol-induced gastric lesions, reduced volume and acidity of the gastric juice and increased gastric wall mucus (P < 0.05). Furthermore, we showed an interesting correlation between concentration of α-pinene and gastroprotective effect of Hyptis species (P Pearson = 0.98). CONCLUSION: Our data showed that the α-pinene exhibited significant antiulcerogenic activity and a great correlation between concentration of α-pinene and gastroprotective effect of Hyptis species was also observed.
RESUMEN
The effects of 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), an inducer agent of free radicals (peroxyl radical) formation, on the rat tracheal smooth muscle. The experiments were performed on tracheal ring preparations maintained in aerated modified Tyrode solution, in pH 7,4 at 37 °C. The force developed by the tracheal smooth muscle was measured by the isometric force transducer connected to a computerized system. On contractions induced by acetylcholine (10 M), AAPH presented a biphasic effect: contraction potentiation at low concentration on intact and denuded epithelium preparations (CE50 = 0,8776 0,415 mM and CE50 = 0,3338 0,343 mM, respectively); and contraction inhibition at high concentration on intact and denuded epithelium preparations (CE50 = 81,55 62 4,284 mM and CE50 = 57,7786 8,607 mM, respectively). On electromechanic coupling, AAPH inhibited contractions induced by KCl (60 mM) on intact and denuded epithelium preparations (CE50 = 57,4037 4,652 mM and CE50 = 32,9650 2,652 mM, respectively). In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. Comparing the present data with those available in literature for H2O2, we can suggest that these observed effects are not specific for AAPH, but they are derived from the free radicals induced by AAPH.
Asunto(s)
Animales , Ratas , Miocitos del Músculo Liso , Músculo Liso , Tráquea , Contracción Isométrica , Radicales LibresRESUMEN
The effects of 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), an inducer agent of free radicals (peroxyl radical) formation, on the rat tracheal smooth muscle. The experiments were performed on tracheal ring preparations maintained in aerated modified Tyrode solution, in pH 7,4 at 37 °C. The force developed by the tracheal smooth muscle was measured by the isometric force transducer connected to a computerized system. On contractions induced by acetylcholine (10 M), AAPH presented a biphasic effect: contraction potentiation at low concentration on intact and denuded epithelium preparations (CE50 = 0,8776 0,415 mM and CE50 = 0,3338 0,343 mM, respectively); and contraction inhibition at high concentration on intact and denuded epithelium preparations (CE50 = 81,55 62 4,284 mM and CE50 = 57,7786 8,607 mM, respectively). On electromechanic coupling, AAPH inhibited contractions induced by KCl (60 mM) on intact and denuded epithelium preparations (CE50 = 57,4037 4,652 mM and CE50 = 32,9650 2,652 mM, respectively). In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. Comparing the present data with those available in literature for H2O2, we can suggest that these observed effects are not specific for AAPH, but they are derived from the free radicals induced by AAPH.(AU)