Propriedades de proteção gastrointestinal da Rosmarinus officinalis l. em associação a testes microbiológicos e antioxidantes in vitro e ex vivo

Abstract

The elevate production of reactive species over physiological levels and associated to pathogenic bacteria could represent a high risk for many diseases. The high levels of oxidative stress and inflammation can be present in the etiology of gastrointestinal pathologies associated with ethanol ingestion, and sometimes with implication in liver or brain. Peptic ulcer includes gastric and intestinal damage that affect many people around the world and its development is a result of the imbalance between aggressive and protective factors. The Rosmarinus officinalis L., more commonly known as rosemary in Europe and as alecrim in Brazil, has exhibited several physiological and medicinal activities against some diseases mainly due its phenolic compounds. So in this thesis, the aim was to perform analyzes in vitro and ex vivo on the antioxidant properties of the ethanolic extract of Rosmarinus officinalis L. (eeRo) and its fractions (DCM, EA, ButOH), and about their antibacterial activities and the possible applicability of eeRo on gastrointestinal protection. The eeRo was obtained from the dried leaves (40ºC) subjected to an alcoholic extraction in the soxhlet apparatus. The eeRo was separately to dichloromethane, ethyl acetate and butanol in a separator funnel to get DCM, EA and ButOH fractions, respectively. The quantification of constituents of eeRo and its fractions were made by HPLC–DAD. The eeRo and its fractions were tested in the DPPH•- radical scavenging, total antioxidant capacity assays without tissues and they were tested in sodium nitroprusside-induced lipid peroxidation and H2DCF-DA in liver, brain and stomach of male adult wistar rats. The eeRo and its fractions were analyzed in bacteria minimum inhibitory concentration assay. Besids, eeRo and its fractions were tested in ethanol-induced gastric and intestinal lesions models. After application of these models and pretreatment with eeRo the dichlorofluorescein fluorescence, lipid peroxidation, ratio of GSH/GSSG, superoxide dismutase activity, catalase activity, myeloperoxidase activity assays were performed in stomach and intestine. Moreover, the measurement of nitrite and nitrate levels, ulcer index and histopathology tests were made only in stomach. The Na+/K+ ATPase activity was measured only in intestine. The eeRo, DCM, EA had significant total antioxidant effect and DPPH•- radical scavenging activity in vitro. The DCM and eeRo got antioxidant effects against basal levels of reactive species in the liver, stomach and brain. The eeRo and DCM protected the liver and brain against lipid peroxidation induced by sodium nitroprussiate. The eeRo, DCM, EA and ButOH had inhibitory effect in the gram (+) and gram (-) bacteria. However, the eeRo and DCM, had the lower minimum inhibitory concentration.The eeRo, after in vivo treatment protected stomach and intestine against the lipid peroxidation and they increased the CAT activity. The eeRo prevented the reduction in Na+/K+ ATPase and cased the increase of superoxide dismutase activity in intestine. In addition, eeRo reduced the myeloperoxidase activity in stomach and intestine. The results of this tese suggest that the eeRo, in general way, represented the better option as agent against oxidative stress in vitro, ex vivo e mainly in the prevention of gastrointestinal lesions in association to anti-inflamatory or vasodilatory mechanisms.