Neoglaziovia variegata (Arruda) Mez (Bromeliaceae) is a medicinal plant popularly known as "caroá." The leaves are made up of highly resistant fibers, which is of great commercial value to the handicraft and textile industry. Some studies have demonstrated that ethanolic extract of N. variegata have gastroprotective properties. This study aimed to investigate the gastroprotective activity and cytoprotective mechanisms of ethyl acetate (Nv-AcOEt), hexane (Nv-Hex), and chloroform (Nv-CHCl3) fractions of N. variegata leaves. The gastroprotective activity of Nv-AcOEt, Nv-Hex, and Nv-CHCl3 was evaluated using the ethanol and ethanol/HCl-induced gastric injury model. To elucidate the gastroprotective mechanisms, the functions of prostaglandins (PGs), nitric oxide (NO), and KATP channels were evaluated. In addition, the nonprotein sulfhydryl groups and the mucus content in the gastric tissues were analyzed. All fractions of N. variegata leaves at oral doses of 100, 200, and 400 mg/kg significantly decreased ethanol and ethanol/HCl-induced gastric lesions, leading to gastroprotection, accompanied by an increase in reduced glutathione (GSH) and gastric mucus. Gastroprotective activity of Nv-AcOEt was inhibited after pretreatment with ibuprofen and N(G)-nitro-L-arginine (L-NOARG). Gastroprotective effect of Nv-Hex and Nv-CHCl3 was also inhibited after pretreatment with L-NOARG and with glibenclamide. The results indicate that N. variegata (Arruda) Mez exhibits promising gastroprotective activity with the possible participation of NO, PGs, mucus, sulfhydryl groups, and KATP.
Keywords: antioxidant activity; gastroprotection • Neoglaziovia variegata.