Enhanced therapeutic benefit of quercetin-loaded phytosome nanoparticles in ovariectomized rats.

Quercetin, a dietary flavonol phytoestrogen, has many health benefits but it is poorly absorbed when administered orally. To improve its bioavailability, we prepared quercetin-loaded phytosome nanoparticles (QP) using the thin film hydration method. The prepared nano-formulations were characterized using different techniques. Transmission electron microscopy revealed the homogeneously spherical, well and uniformly dispersed, nano-sized nature of QP. Dynamic light scattering measurements of QP (70 ± 7.44 nm) also confirmed this. Stability of the formed nanoparticles was established via zeta potential determination. The prepared QP exhibited very high encapsulation efficiency (98.4%). The estrogenic activity of QP, concerning inflammation, oxidative stress, bone, lipid profile, blood glucose level and weight gain, was investigated in ovariectomized rat model using 10 and 50 mg/kg/day oral doses for 4 weeks. Treatment with QP showed significant increase in serum calcium, inorganic phosphorus and glutathione content. Whereas, it significantly decreased serum alkaline phosphatase, acid phosphatase, malondialdehyde level, tumor necrosis factor-alpha and glucose level and improved lipid profile. Consequently, the results obtained confirm the superiority of QP over free quercetin at the same doses as a promising hormone replacement therapy.