Formulation, physico-chemical characterization and antidiabetic potential of naringenin-loaded poly D, L lactide-co-glycolide (N-PLGA) nanoparticles

The insolubility of bioflavonoids in water and low bioavailability restrict their uses to a great extent, which can be overcome by encapsulated polymer nanoparticles. We have prepared naringenin (a bioflavonoid) bearing polymer PLGA (N-PLGA) nanoparticles by emulsion-diffusion-evaporation method. The encapsulation efficiency was nearly 70%. N-PLGA nanoparticles were about 129 nm in diameters, as determined by DLS and approximately 90 nm diameters determined by AFM and TEM. The nanoparticles exhibited higher melting temperature (350 degrees C) than free naringenin (253 degrees C). FT-IR spectroscopic study confirmed the formulation of N-PLGA nanoparticles. Free naringenin and N-PLGA nanoparticles were tested in streptozotocin-induced diabetic rats. Diabetic rats were treated (i.p) with 10 mg free naringenin or N-PLGA nanoparticles containing 10 mg naringenin/kg body weight. After 10 days, second dose was administered to both group of rats, as the blood glucose level was still higher than normal. After second dose, blood glucose level became normal in nanoparticle-treated rats, but not in free naringenin-treated rats. Significant reduction in glycated hemoglobin level, increase in insulin level and improvement of dyslipidemia and oxidative stress parameters were found in N-PLGA treated-group, in comparison with the respective parameters in free naringenin-treated group. The findings thus suggest better antidiabetic potential of N-PLGA nanoparticles in comparison with the free flavonoid.