Development of liposomal ginsenoside Rg3: Formulation optimization and evaluation of its anticancer effects

The Ginsenoside Rg3 has been shown to possess antiangiogenic and anticancer properties. Because of its limited water solubility, we decided to design and synthesize liposomal Rg3 (L-Rg3), to optimize preparation conditions, and to investigate further whether liposome could enhance the anticancer activity of Rg3. L-Rg3 was prepared using a film-dispersion method and the preparation conditions were optimized with response surface methodology (RSM). The mean encapsulation efficiency (EE) of 82.47% was close to the predicted value of 89.69%. Therefore, the optimized preparation condition was predicted correctly. We evaluated the cytotoxicity, pharmacokinetics, biodistribution and antitumor activities of L-Rg3. HepG2 and A549 cells were treated with Rg3 or L-Rg3 at different concentrations in vitro. Pharmacokinetics and biodistribution studies were carried out in Wistar rats. Tumor model was established by inoculating a suspension of A549 cells into BALB/c nude mice. The mice were divided into Saline, Rg3 solution, and L-Rg3 groups with the drug given by i.p. injection. Survival of the mice and tumor volume were monitored. In addition, CD34 immunohistochemical analysis was used for measuring microvessel density (MVD) of the tumor tissues. The cytotoxicity and ratio of tumor inhibition of L-Rg3 group were significantly higher than the Rg3 solution group. MVD values in the Rg3 solution and L-Rg3 groups decreased, especially in the L-Rg3 group. Compared to Rg3 solution, the L-Rg3 showed increased C_max and AUC of Rg3 by 1.19- and 1.52-fold, respectively. This liposomal formulation could potentially produce a viable clinical agent for improving the anticancer activity of Rg3.