Ginsenoside Rb1 stabilized and paclitaxel / protopanaxadiol co-loaded nanoparticles for synergistic treatment of breast tumor

Ginsenosides are the major and key components for ginseng to exert its wide and beneficial therapeutic efficacy in clinic. Meanwhile, many ginsenosides and their metabolites showed in vitro an in vivo anti-tumor activity, among which ginsenoside Rb1 has attracted much attention due to its good solubility and amphipathy. In this study, the self-assembly behavior of Rb1 was investigated and the Rb1 nano-assembly could further stabilize or encapsulated hydrophobic drugs such as protopanaxadiol (PPD) and paclitaxel (PTX) to form nanoparticles, based on which, a natural nanoscale drug delivery system, ginsenoside Rb1 stabilized and PTX/PPD co-loaded nanoparticles (GPP NPs) were prepared. The resultant GPP NPs exhibited a small particle size of 126.2 nm, a narrow size distribution (PDI=0.145), and a zeta potential of -27.3 mV. PTX loading content was 11.06% with an encapsulation efficiency of 93.86%. GPP NPs were spherical and stable in normal saline, 5% glucose, PBS, plasma, or on-shelf storage for 7 days. Both PTX and PPD existed in an amorphous state in GPP NPs and were released in a sustained pattern. GPP NPs showed 10-fold higher in vitro anti-tumor activity of than PTX injections. In the in vivo experiment, GPP NPs achieved a much higher tumor inhibition rate than PTX injections (64.95% vs 43.17%, P < 0.01) and certain tumor target ability. In conclusion, GPP NPs had significantly enhanced anti-tumor efficacy and improved tumor microenvironment, thus were promising to be developed into a novel anti-tumor agent for the treatment of breast tumor.