Artesunate, as an Hsp90 inhibitor, inhibits the proliferation of Burkitt's lymphoma cells by inhibiting AKT and ERK.

Introduction: Artesunate, a derivative of artemisinin, has anti-malarial effects, and in recent years has also been reported to have anti-tumor activity. However, its anti-tumor mechanisms are not well understood. Methods: In this study, we focused on the targeting of Hsp90 by artesunate to inhibit tumor cell proliferation, which we examined using immunoprecipitation, a proliferation assay, flow cytometry, western blotting, a tumor xenograft animal model, and immunohistochemistry. Furthermore, to examine the tumor-suppressive effects of artesunatein nude mice, we used artesunate-loaded PLGA-PEG nanoparticles. Results: The binding of artesunate to Hsp90 was found to reduce the expression of its client proteins AKT, ERK, p-AKT, p-ERK, and EGFR, thereby blocking the cell cycle at the G0/G1 → S stage in lymphoma cells and inducing apoptosis. In addition, the results of tumor xenograft experiments revealed that artesunate reduced the expression of AKT and ERK proteins in tumor tissues, inhibited tumor proliferation, and reduced tumor size and weight. Furthermore, nanoparticle encapsulation was demonstrated to enhance the anti-cancer activity of artesunate. Discussion: We thus established that artesunate inhibits the proliferation of lymphoma cells by targeting the Hsp90 protein, and we accordingly believe that this compound has potential for development as a novelanti-tumor drug.

Physalis pubescens L. branch and leaf extracts inhibit lymphoma proliferation by inducing apoptosis and cell cycle arrest.

Physalis pubescens L. is an annual or perennial plant in the family Solanaceae It is used in traditional medicine for treating sore throats, coughs, urinary discomfort, and astringent pain, and externally for pemphigus and eczema in northern China. The proliferation inhibitory activity and mechanisms of the ethyl acetate extract (PHY-EA) from the leaves of Physalis pubescens were investigated. High performance liquid chromatography was used to identify the chemical composition of PHY-EA; sulforhodamine B was used to detect the proliferation inhibitory effect of PHY-EA on MCF-7, CA-46, Hela, HepG2, B16, and other tumor cells; flow cytometry was used to detect the effect of PHY-EA on the lymphoma cell cycle and apoptosis; Western blot was used to detect the expression of the cycle- and apoptosis-related proteins. The expression of Ki-67 and cleaved caspase 3 was detected by immunohistochemistry. The results showed that PHY-EA contained physalin B, physalin O, and physalin L. PHY-EA blocked the cell cycle of G2/M→G0/G1 in lymphoma cells and induced apoptosis in tumor cells. Mouse transplantation tumor experiments showed that PHY-EA had a significant inhibitory effect on mouse transplantation tumors, and the tumor volume and weight were significantly reduced. In conclusion, PHY-EA has a good antiproliferative effect on Burkkit lymphoma, indicating its potential medicinal value.