The novel bis-benzylisoquinoline PY35 reverses P-glycoprotein-mediated multidrug resistance

Phytochemicals: Potential Lead Molecules for MDR Reversal

Multidrug resistance (MDR) is one of the main impediments in the treatment of cancers. MDR cancer cells are resistant to multiple anticancer drugs. One of the major mechanisms of MDR is the efflux of anticancer drugs by ABC transporters. Increased activity and overexpression of these transporters are important causes of drug efflux and, therefore, resistance to cancer chemotherapy. Overcoming MDR is a fundamental prerequisite for developing an efficient treatment of cancer. To date, various types of ABC transporter inhibitors have been employed but no effective anticancer drug is available at present, which can completely overcome MDR. Phytochemicals can reverse MDR in cancer cells via affecting the expression or activity of ABC transporters, and also through exerting synergistic interactions with anticancer drugs by addressing additional molecular targets. We have listed numerous phytochemicals which can affect the expression and activity of ABC transporters in MDR cancer cell lines. Phytochemicals in the groups of flavonoids, alkaloids, terpenes, carotenoids, stilbenoids, lignans, polyketides, and curcuminoids have been examined for MDR-reversing activity. The use of MDR-reversing phytochemicals with low toxicity to human in combination with effective anticancer agents may result in successful treatment of chemotherapy-resistant cancer. In this review, we summarize and discuss published evidence for natural products with MDR modulation abilities.

A modular approach to the bisbenzylisoquinoline alkaloids tetrandrine and isotetrandrine

A modular short-step synthesis of the bisbenzylisoquinoline alkaloids tetrandrine and isotetrandrine was developed employingN-acyl-Pictet–Spengler reaction and Ullman diaryl ether synthesis as central steps.

Redox-responsive F127-folate/F127-disulfide bond-d-α-tocopheryl polyethylene glycol 1000 succinate/P123 mixed micelles loaded with paclitaxel for the reversal of multidrug resistance in tumors

Introduction

The development of nanodrug carriers utilizing tumor microenvironment has become a hotspot in reversing multidrug resistance (MDR).

Materials and methods

This study synthesized a redox-sensitive copolymer, Pluronic F127-disulfide bond-d-α-tocopheryl polyethylene glycol 1000 succinate (FSST), through the connection of the reduction-sensitive disulfide bond between F127 and d-α-tocopheryl polyethylene glycol 1000 succinate. This polymer could induce the elevation of reactive oxygen species (ROS) levels, ultimately resulting in cytotoxicity. Moreover, the redox-responsive mixed micelles, F127-folate (FA)/FSST/P123 (FFSSTP), based on FSST, Pluronic F127-FA, and Pluronic P123, were prepared to load paclitaxel (PTX).

Results

The in vitro release study demonstrated that FFSSTP/PTX accelerated the PTX release through the breakage of disulfide bond in reductive environment. In cellular experiment, FFSSTP/PTX induced significant apoptosis in PTX-resistant MCF-7/PTX cells through inhibiting adenosine triphosphate (ATP)-binding cassette proteins from pumping out PTX by interfering with the mitochondrial function and ATP synthesis. Furthermore, FFSSTP/PTX induced apoptosis through elevating the intracellular levels of ROS.

Conclusion

FFSSTP could become a potential carrier for the treatment of MDR tumors.

Tetrandrine, a Chinese plant-derived alkaloid, is a potential candidate for cancer chemotherapy

Cancer is a disease caused by the abnormal proliferation and differentiation of cells governed by tumorigenic factors. Chemotherapy is one of the major cancer treatment strategies, and it functions by targeting the physiological capabilities of cancer cells, including sustained proliferation and angiogenesis, the evasion of programmed cell death, tissue invasion and metastasis. Remarkably, natural products have garnered increased attention in the chemotherapy drug discovery field because they are biologically friendly and have high therapeutic effects. Tetrandrine, isolated from the root of Stephania tetrandra S Moore, is a traditional Chinese clinical agent for silicosis, autoimmune disorders, inflammatory pulmonary diseases, cardiovascular diseases and hypertension. Recently, the novel anti-tumor effects of tetrandrine have been widely investigated. More impressive is that tetrandrine affects multiple biological activities of cancer cells, including the inhibition of proliferation, angiogenesis, migration, and invasion; the induction of apoptosis and autophagy; the reversal of multidrug resistance (MDR); and the enhancement of radiation sensitization. This review focuses on introducing the latest information about the anti-tumor effects of tetrandrine on various cancers and its underlying mechanism. Moreover, we discuss the nanoparticle delivery system being developed for tetrandrine and the anti-tumor effects of other bisbenzylisoquinoline alkaloid derivatives on cancer cells. All current evidence demonstrates that tetrandrine is a promising candidate as a cancer chemotherapeutic.

Isochondodendrine and 2′-norcocsuline: additional alkaloids from Triclisia subcordata induce cytotoxicity and apoptosis in ovarian cancer cell lines

Triclisia subcordata Oliv (Menispermeaceae) is used in herbal medicine for the treatment of cancer and other diseases in Africa.