Gastroprotective effect and mechanism of action of Croton rhamnifolioides essential oil in mice.

BACKGROUND: Croton rhamnifolioides Pax is a plant species that have been used in the folk medicine to treat ulcers, inflammations and hypertension. However, despite the relevant data obtained from ethnopharmacological studies, the pharmacological properties endorsing the efficacy of this plant to treat ulcer remain to be elucidated. HYPOTHESIS/PURPOSE: The present study aimed to characterize the chemical profile and evaluate the gastroprotective activity of the essential oil obtained from C. rhamnifolioides Pax (OECC) in mice. METHODS: The essential oil of Croton rhamnifolioides was obtained by hydrodistillation and analyzed by gas-phase chromatography coupled to mass spectrometry (GC/MS). The median lethal dose was determined employing an acute toxicity test. The gastroprotective activity of the OECC was investigated using animal models of gastric ulcer induced by the administration of absolute ethanol, acidified ethanol or indomethacin. Mechanisms of action were investigated using the physical barrier test and by in vivo evaluation of the involvement of the following molecular pathways: nitric oxide, ATP - dependent potassium channels, α2 - noradrenergic receptors, capsaicin - sensitive afferent neurons and opioid receptor. RESULTS: We identified the presence of 21 compounds in OECC, including spathulenol and 1,8 - cineole as major constituents. In orally administered mice, OECC caused no significant toxicity. OECC significantly prevented gastric lesions in all mice models. The barrier test demonstrated that the gastroprotective activity of OECC occurs in a systemic dimension. Our results demonstrated that the gastroprotective effect of OECC involves mechanisms that are related to modulation of opioid receptors and nitric oxide. CONCLUSION: In conclusion, OECC demonstrated significant gastroprotective activity associated with low toxicity, providing scientific evidences that C. rhamnifolioides have the potential for the development of new antiulcer drugs.

Chemical composition, antibacterial and modulatory action of the essential oil of Croton rhamnifolioides leaves Pax and Hoffman / Composição química, ação antibacteriana e moduladora do óleo essencial das folhas de Croton rhamnifolioides Pax and Hoffman

The species Croton rhamnifolioides is a shrub popularly known as "quebra faca", utilized in teas or infusions for the treatment of gastrointestinal disorders as ulcers, gastric discomfort, vomiting and hemorrhagic diarrhea. This work has as its main objective to evaluate the chemical composition of the essential oil of the Croton rhamnifolioides leaves (EOC), antibacterial activity and modulatory activity of antibiotic resistance, against bacterial strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and, and antifungal activity against Candida albicans, Candida krusei and Candida tropicalis. The chemical composition was determined through chromatography with a gas phase coupled with mass spectrometry (CG/MS), whereas antimicrobial activity and modulation were determined by microdilution assay. The chemical composition of the oil revealed 21 compounds, with the major compounds being spathulenol (22.46%) and 1,8-cineol (18.32%). The antimicrobial activity was not significant with MIC>1024 µg/mL, however, was observed a synergistic interference when essential oil associated with the antibiotics aminoglycoside and -lactam, and the antifungal polyene.

Croton rhamnifolioides is é um arbusto conhecido popularmente como "quebra-faca" e utilizado como chá ou infusão para o tratamento de problemas gastro-intestinais como úlceras, desconforto gástrico, vômitos e diarréias hemorrágicas. O objetivo deste trabalho foi avaliar a composição química do óleo essencial das folhas de Croton rhamnifolioides (OEC), atividade antibacteriana, moduladora da resistência bacteriana, contra linhagens bacterianas de Escherichia coli, Staphylococcus aureus e Pseudomonas aeruginosa e, atividade antifúngica contra Candida albicans, C. krusei e C. tropicalis. A composição química foi determinada através de Espectroscopia de Massas acoplada a Cromatografia Gasosa (EM/CG), enquanto as atividades antimicrobianas e moduladoras foram determinadas pelo método de microdiluição. A composição química do OEC revelou a presença de 21 compostos, sendo os principais o Espatulenol (22,46%) e 1,8-cineol (18,32%). A atividade antimicrobiana não foi considerada significativa apresentando MIC > 1024 µg/mL, contudo, foi observado um sinergismo quando o óleo essencial foi associado com aminoglicosídios, -lactâmicos e antifúngicos poliênicos.