In the current study, we investigated the effect of propolis on diabetic mice undergoing propolis treatment (150 mg/kg/day) for a 6 week period. We also evaluated serum lipids, glucose, insulin levels and the effect on glucose uptake of 2-deoxy-D-[2,6-3H] glucose, [14C]-glycogen synthesis and [U-14C]-D-glucose decarboxylation induced by insulin in muscle tissue. Our results show that treatment with propolis (150 mg/kg/day) reduced insulin and HOMA index (P<0.05). Propolis also lowered abdominal obesity (P<0.05). No effects over serum glucose, total cholesterol and triglycerides levels were observed. We also observed that uptake of 2-deoxy-D-[2,6-3H] glucose, [14C]-glycogen synthesis and [U-14C]-D-glucose decarboxylation induced by insulin in soleus muscle of mice treated with propolis were significantly greater than control group (P<0.05). In summary, our data establishes that propolis modulates glucose metabolism. This result constitutes important data indicating that propolis can be used as a polyphenols source with antidiabetogenic activity.

En el presente estudio se evaluó el efecto del propóleos sobre el metabolismo de la glucosa en ratones C57/BL-6 con diabetes mellitus tipo 2 inducida por dieta alta en grasa. Se midieron los cambios en las concentraciones séricas de lípidos, glucosa e insulina, y el efecto sobre la captación de 2-deoxi-[2,6-3H]-D-glucosa, síntesis de [14C]-glicógeno y descarboxilación de [U-14C]-D-glucosa inducida por insulina en músculo aislado. Los resultados muestran que en ratones diabéticos, el tratamiento con propóleos (150 mg/kg/día) reduce los niveles de insulina e índice HOMA (P<0.05). También disminuyó la obesidad abdominal de estos animales (P<0.05). Por otro lado, no modificó las concentraciones plasmáticas de glucosa, colesterol total y triglicéridos. Se observó también que la captación de 2-deoxi-[2,6-3H]-D-glucosa, síntesis de [14C]-glicógeno y descarboxilación de [U-14C]-D-glucosa inducida por insulina en músculo sóleo de ratones tratados con propóleos fue significativamente superior al grupo control (P<0.05). En resumen, nuestros datos confirman que el propóleos es capaz de modular el metabolismo de glucosa en ratones C57/BL-6 con diabetes mellitus tipo 2 inducida por dieta alta en grasa. Los datos obtenidos constituyen un importante antecedente que avala el posible uso del propóleos como fuente de polifenoles con actividad antidiabetogénica.

OBJECTIVE: To assess the effect of endogenous estrogens on the bioavailability of nitric oxide (·NO) and in the formation of lipid peroxidation products in pre- and postmenopausal women. METHODS: NOx and S-nitrosothiols were determined by gaseous phase chemiluminescence, nitrotyrosine was determined by ELISA, COx (cholesterol oxides) by gas chromatography, and cholesteryl linoleate hydroperoxides (CE18:2-OOH), trilinolein (TG18:2-OOH), and phospholipids (PC-OOH) by HPLC in samples of plasma. RESULTS: The concentrations of NOx, nitrotyrosine, COx, CE18:2-OOH, and PC-OOH were higher in the postmenopausal period (33.8±22.3 mM; 230±130 nM; 55±19 ng/mL; 17±8.7 nM; 2775±460 nM, respectively) as compared with those in the premenopausal period (21.1±7.3 mM; 114±41 nM; 31±13 ng/mL; 6±1.4 nM; 1635±373 nM). In contrast, the concentration of S-nitrosothiols was lower in the postmenopausal period (91±55 nM) as compared with that in the premenopausal p in the premenopausal period (237±197 nM). CONCLUSION: In the postmenopausal period, an increase in nitrotyrosine and a reduction of S-nitrosothiol formation, as well as an increase of COx, CE18:2-OOH and PC-OOH formation occurs. Therefore, •NO inactivation and the increase in lipid peroxidation may contribute to endothelial dysfunction and to the greater risk for atherosclerosis in postmenopausal women.