Role of endogenous SHs and NO on Vernonia ferruginea Less induced gastroprotection

The methanolic crude extract (MeOH) obtained from aerial parts of Vernonia ferruginea Less. (Asteraceae), a Brazilian savannah plant popularly known as “assa-peixe“, was investigated for its antiulcerogenic proprieties and mechanisms employing three experimental models. Preliminar phytochemical screening showed that glycoside flavonoids are the major compounds present in this extract. To obtain MeOH, aerial parts of V. ferruginea were air dried (7 days at 40^oC) and powdered. The powder (100g) were exhaustively extracted with methanol at room temperature (3 times for 72h) and then concentrated in a vacuum rotator evaporator. The previous administration of MeOH (50, 100, 250 and 500mg/kg) significantly inhibited the gastric mucosa damage, from the 100mg/kg dose (91% of inhibition), caused by absolute ethanol oral administration in rats. This antiulcerogenic propriety of MeOH (100mg/kg) depends in part on endogenous NO, once its gastroprotection was lightly attenuated by pretreatment with NG-nitro-L-arginine methyl-ester, a NO-Synthase inhibitor. Besides, when animals were pretreated with N-ethylmaleimide, a thiol blocker, including mucosal nonprotein sulfhydryl groups (SHs), the gastroprotective effects of MeOH have been extinguished. These results show that MeOH gastroprotective proprieties are due to the cytoprotective proprieties of NO and mainly of endogenous sulfhydryls compounds.

Acknowledgements: FAPESP, CNPq and CAPES.