RESUMO
The aim of the present study was to investigate the effect of C. papaya L. leaf extract (CPLE) on pancreatic islets in streptozotocin (STZ)-induced diabetic rats, as well as on cultured normal pancreatic cells with STZ in the medium. CPLE (3-125 mg/Kg) was administered orally for 20 days, while a group of diabetic rats received 5 IU/Kg/day of insulin. At the end of the treatment the rats were sacrificed. Blood was obtained to assess glucose and insulin levels. The pancreas was dissected to evaluate ß cells by immunohistochemistry. In addition, normal pancreatic cells were cultured in a medium that included CPLE (3-12 mg). One half of the cultured cells received simultaneously CPLE and STZ (6 mg), while the other half received CPLE and five days later the STZ. After three days of incubation, insulin was assayed in the incubation medium. The CPLE administered to diabetic rats improved the fasting glycemia and preserved the number and structure of pancreatic islets. However, when CPLE was added to pancreatic cells in culture along with STZ, the insulin concentration was higher in comparison with the cells that only received STZ. In conclusion, the CPLE preserves the integrity of pancreatic islets, improves the basal insulin secretion and protects cultured cells from the adverse effects of STZ.
Assuntos
Carica/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Ilhotas Pancreáticas/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Animais , Glicemia/análise , Células Cultivadas , Imuno-Histoquímica , Insulina/sangue , Masculino , México , Fitoterapia , Extratos Vegetais/uso terapêutico , Ratos , Ratos Wistar , EstreptozocinaRESUMO
The extraction of plant constituents is essential to isolate biologically active compounds, aimed to understand their role on the treatment of diabetes. This study was designed to explore the preliminary phytochemical and physicochemical analysis of Carica papaya L., Caricaceae, leaf, and further evaluation of its hypoglycemic effect on diabetic rats. C. papaya leaves were extracted using chloroform, n-hexane or ethanol. For each extract a phytochemical screening was performed. The tests were conducted in triplicate and the qualitative and quantitative determination of the various metabolites was done using analytical standards proposed by Mexican Herbal Pharmacopoeia. The chloroform extract, containing steroids and quinones as major components, was chosen to study C. papaya biological effects. The chloroform extract was evaporated to dryness, and doses 0, 31, 62, 125 mg/kg were orally administered in 300 µl polyethylene glycol to diabetic rats; and 0 and 62 mg/kg to non-diabetic rats. After a 20-day treatment with the chloroform extract, the animals were sacrificed and blood was obtained for biochemical studies. The main effect observed was a decrease in serum glucose, triglycerides and transaminases in diabetic rats after the administration of C. papaya chloroform extract. These results confirm the potential beneficial action of C. papaya to treat the symptoms of diabetic patients.