ABSTRACT
Tumors are still a major threat to people worldwide. Nanodrug delivery and targeting systems can significantly improve the therapeutic efficacy of chemotherapeutic drugs for antitumor purposes. However, many nanocarriers are likely to exhibit drawbacks such as a complex preparation process, limited drug-loading capacity, untargeted drug release, and toxicity associated with nanocarriers. Therefore, new therapeutic alternatives are urgently needed to develop antitumor drugs. Natural products with abundant scaffold diversity and structural complexity, which are derived from medicinal plants, are important sources of new antitumor drugs. Here, two carrier-free berberine (BBR)-based nanoparticles (NPs) were established to increase the synergistic efficacy of tumor treatment. BBR can interact with glycyrrhetinic acid (GA) and artesunate (ART) to self-assemble BBR-GA and BBR-ART NPs without any nanocarriers, respectively, the formation of which is dominated by electrostatic and hydrophobic interactions. Moreover, BBR-GA NPs could lead to mitochondria-mediated cell apoptosis by regulating mitochondrial fission and dysfunction, while BBR-ART NPs induced ferroptosis in tumor cells. BBR-based NPs have been demonstrated to possess significant tumor targeting and enhanced antitumor properties compared with those of simple monomer mixes both in vitro and in vivo. These carrier-free self-assemblies based on natural products provide a strategy for synergistic drug delivery and thus offer broad prospects for developing enhanced antitumor drugs.
ABSTRACT
The glucose transporter 1 (GLUT1) protein is involved in the basal-level absorption of glucose in tumor cells. Inhibiting GLUT1 decreases tumor cell proliferation and induces tumor cell damage. Natural GLUT1 inhibitors have been studied only to a small extent, and the structures of known natural GLUT1 inhibitors are limited to a few classes of natural products. Therefore, discovering and researching other natural GLUT1 inhibitors with novel scaffolds are essential. Physalis angulata L. var. villosa is a plant known as Mao-Ku-Zhi (MKZ). Withanolides are the main phytochemical components of MKZ. MKZ extracts and the components of MKZ exhibited antitumor activity in recent pharmacological studies. However, the antitumor-active components of MKZ and their molecular mechanisms remain unknown. A cell membrane-biomimetic nanoplatform (CM@Fe3O4/MIL-101) was used for target separation of potential GLUT1 inhibitors from MKZ. A new withanolide, physagulide Y (2), together with six known withanolides (1, 3-7), was identified as a potential GLUT1 inhibitor. Physagulide Y was the most potent GLUT1 inhibitor, and its antitumor activity and possible mechanism of action were explored in MCF-7 human cancer cells. These findings advance the development of technologies for the targeted separation of natural products and identify a new molecular framework for the investigation of natural GLUT1 inhibitors.