Polymeric micelles for potentiated antiulcer and anticancer activities of naringin.

Naringin is one of the most interesting phytopharmaceuticals that has been widely investigated for various biological actions. Yet, its low water solubility, limited permeability, and suboptimal bioavailability limited its use. Therefore, in this study, polymeric micelles of naringin based on pluronic F68 (PF68) were developed, fully characterized, and optimized. The optimized formula was investigated regarding in vitro release, storage stability, and in vitro cytotoxicity vs different cell lines. Also, cytoprotection against ethanol-induced ulcer in rats and antitumor activity against Ehrlich ascites carcinoma in mice were investigated. Nanoscopic and nearly spherical 1:50 micelles with the mean diameter of 74.80±6.56 nm and narrow size distribution were obtained. These micelles showed the highest entrapment efficiency (EE%; 96.14±2.29). The micelles exhibited prolonged release up to 48 vs 10 h for free naringin. The stability of micelles was confirmed by insignificant changes in drug entrapment, particle size, and retention (%) (91.99±3.24). At lower dose than free naringin, effective cytoprotection of 1:50 micelles against ethanol-induced ulcer in rat model has been indicated by significant reduction in mucosal damage, gastric level of malondialdehyde, gastric expression of tumor necrosis factor-alpha, caspase-3, nuclear factor kappa-light-chain-enhancer of activated B cells, and interleukin-6 with the elevation of gastric reduced glutathione and superoxide dismutase when compared with the positive control group. As well, these micelles provoked pronounced antitumor activity assessed by potentiated in vitro cytotoxicity particularly against colorectal carcinoma cells and tumor growth inhibition when compared with free naringin. In conclusion, 1:50 naringin-PF68 micelles can be represented as a potential stable nanodrug delivery system with prolonged release and enhanced antiulcer as well as antitumor activities.

Enhanced in vitro cytotoxicity and anti-tumor activity of vorinostat-loaded pluronic micelles with prolonged release and reduced hepatic and renal toxicities.

Vorinostat is the first histone deacetylase inhibitor approved by US FDA for use in cancer therapy. However, its limited aqueous solubility, low permeability, and suboptimal pharmacokinetics hinder its delivery. Thus, in this study, micelles of vorinostat with each of pluronic F68 (PF68) and pluronic F127 (PF127) were developed and optimized based on drug loading and entrapment. The optimized micelles were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), zeta analyzer, and electron transmission microscopy. Their in vitro release, stability, in vitro cytotoxicity against HepG2, Caco-2, and MCF-7 cell lines, and finally, in vivo antitumor activity in mice bearing Ehrlich Ascites Carcinoma (EAC) were assessed. The highest entrapment efficiency was 99.09±2.16% and 94.19±2.37% for micelles of 1:50 drug to polymer ratio with each of PF127 and PF68, respectively. These micelles were nearly spherical with nanoscopic mean diameters of 72.61±10.66nm for PF68 and 91.88±10.70nm for PF127 with narrow size distribution. The micelles provided prolonged release at phosphate buffer saline pH7.4 up to 24h for PF68 and 72h for PF127. Potentiation of in vitro cytotoxicity of vorinostat was more pronounced with PF127 micelles particularly against MCF-7 cells. Compared with free vorinostat, the micelles with PF127 were more effective in inhibiting tumor growth as well as exhibiting significantly (p<0.05) diminished hepatic and renal toxicities. In conclusion, 1:50 vorinostat-PF127 micelles may facilitate i.v. formulations and can be suggested as a promising stable and safe nanoparticulate delivery system with prolonged release and potentiated cytotoxicity.