Effect of Gongronema latifolium ethanol leaf extract on gastric acid secretion and cytoprotection in streptozotocin-induced diabetic rats / Efecto del extracto de etanol de las hojas de Gongronema latifolium sobre la secreción del ácido gástrico y la citoprotección en ratas con diabetes inducida por estreptozotocina

OBJECTIVES: Gongronema latifolium leaves have been used in folklore medicine to manage diabetes mellitus and alleviate dyspepsia. This study aimed to provide a pharmacological basis to the medicinal use of Gongronema latifolium as an antidiabetic and antiulcerogenic agent in diabetes mellitus. METHODS: Ethanol extract from the leaf (200 mg/kg bodyweight) of Gongronema latifolium was administered to both streptozotocin-induced diabetic and control groups orally for 14 days. Gastric acid secretion was measured and ulcer was induced using ethanol and fourhour pyloric ligation. RESULTS: The mean bodyweight was significantly lower (p < 0.01), while the mean weight of the stomach, liver and small intestine to bodyweight ratio was increased significantly (p < 0.05) in the two diabetic groups compared to control. Extract significantly (p < 0.01) reduced the blood glucose level similar to the nondiabetic control. Basal and stimulated acid secretion in diabetic control rats was significantly (p < 0.01) decreased when compared to control. Extract administration increased the stimulated gastric acid secretion to a level significantly (p < 0.05) higher than control while reduction in gastric secretion by ranitidine was similar compared with control. Gongronema latifolium treatment significantly (p < 0.05) reduced ulcer scores in both ulcer models and increased mucus weight in the diabetic group. CONCLUSION: These results suggest that Gongronema latifolium antiulcerative activity is due to its prevention of chemicalinduced stomach injury.

OBJETIVOS: Las hojas de la gongronema latifolium han sido usadas en la medicina tradicional para tratar la diabetes mellitus y aliviar la dispepsia. Este estudio estuvo dirigido a proporcionar una base farmacológica al uso medicinal de la gongronema latifolium como agente antidiabético y antiulcerogénico en la diabetes mellitus. MÉTODOS: El extracto de etanol de la hoja (200 mg/kg peso corporal) de la Gongronema latifolium se administró oralmente durante 14 días a grupos con diabetes inducida por estreptozotocina, y grupos de control. La secreción ácida gástrica fue moderada y la úlcera fue inducida usando etanol, y ligazón pilórica de cuatro horas. RESULTADOS: El peso corporal promedio fue significativamente más bajo (p < 0.01), mientras que el peso promedio del estómago, el hígado y el intestino delgado con respecto a la proporción del peso corporal aumentó significativamente (p < 0.05) en los dos grupos diabéticos comparados con los controles. El extracto redujo significativamente (p < 0.01) el nivel de glucosa de la sangre, de manera similar al control no diabético. La secreción ácida basal y estimulada en las ratas diabéticas control disminuyó significativamente (p < 0.01) en comparación con el control. La administración del extracto aumentó la secreción ácida gástrica estimulada a un nivel significativamente (p < 0.05) superior al control, en tanto que la reducción de secreción gástrica mediante ranitidina fue similar comparada con el control. El tratamiento con Gongronema latifolium redujo significativamente (p < 0.05) las puntuaciones de las úlceras, tanto en los modelos de la úlcera como en el peso de mucosidad aumentado en el grupo diabético. CONCLUSIÓN: Estos resultados sugieren que la actividad antiulcerosa de la Gongronema latifolium se debe a que previene las lesiones de estómago inducidas por medios químicos.

The water extract of Coleus barbatus Benth decreases gastric secretion in rats

Coleus barbatus (Labiatae) Benth is popularly used in Brazil "for the healing of liver and stomach diseases". The water extract (WE 1 to 10 g/Kg, p.o.) of stem and leaves given to rats and mice did not induce signs of intoxication. Preveious treatment of mice with WE (1 g/kg, p.o.) shortened the sleeping time induced by pentobarbital (50 mg/Kg, i.p.) by 37 por cento, althoyugh the extract alone did not increase the spontaneous activity nor did it induce hyperexcitability. In mice WE (2 g/Kg, p.o.) increased the intestinal transit of charcoal by 30 por cento, while reduced gastric secretions ion rats treated with WE (2g/Kg intraduodenal) 3,9 ± 1.0 to 0.5 ± 0.2 ml/4h, respectively). The treatment also reduced the total acid secretion from 34.4 ± 11.0 to 2.7 ± 0.5 mEq/l and raisedgastric pH from 2.2 ± 0.3 to 6.5 ± 0.8. Treatment with WE (2g/Kg, p.o.) protected against gastric ulcers induced by stress (5.3 ± 1.6 and 1.5 ± 0.5 ulcers/cm²), but did nor protect against indonethacin induced ulcers. The results show that the water extract of C barbatus Benth produces mild stimulation of thecentral nervous system and increases intestinal movements. The extract also reduces gastric secretion indicating an antidyspeptic activity, and protects against gastric ulcers induced by stress.