Novel Tocopherol Succinate-Polyoxomolybdate Bioconjugate as Potential Anti-Cancer Agent

Abstract Up to now, polyoxometalates (POMs) have shown encouraging anti-tumor activities. Unfortunately, the general toxicity with a fateful characteristic has prevented their further clinical application as inorganic drugs. In this study, we synthesized tocopherol succinate-polyoxomolybdate conjugate (T2POMo) as a new organic-inorganic hybrid and evaluated its characteristic in-vitro to introduce a safer and more potent POM derivative in the scope of cancer treatment. We synthesized the hybrid via a simple amidation reaction between POMo and tocopherol succinate (TS) using the carbodiimide strategy. The structure was approved by FTIR and HNMR spectroscopy besides the other techniques. The anti-cancer activity was studied on breast cancer cell (MCF-7) and prostate cancer cell (LNCAP) using MTT method and normal cell non-toxicity was checked on Human umbilical vein endothelial cell (HUVEC) using the same protocol, and the flow cytometry technique was used to investigate the apoptosis. The cytotoxicity studies on the breast cancer cell line (MCF-7), prostate cancer cell line (LNCAP) and human umbilical vein endothelial cell (HUVEC) showed that the presence of tocopherol succinate could change and modulate the potency of the final hybrid (IC50 of 167.3 mg/mL on MCF-7 & 234.1 mg/mL on LNCap respectivley). The results showed more cytotoxicity compared to the parent POMo for T2POMo conjugation on cancerous cells besides no significant cytotoxicity on normal cells. The flow cytometry results showed that the hybrid conjugation could result in a significant increase in apoptosis (60.88%). So tocopherol succinate bioconjugate of POMo as a novel and potent bioactive POMo could be a promising candidate for further pre-clinical assessments.