The cis‐Diammineplatinum(II) Complex of Curcumin: A Dual Action DNA Crosslinking and Photochemotherapeutic Agent

Abstract

[Pt(cur)(NH3)2](NO3) (1), a curcumin-bound cis-diammineplatinum(II) complex, nicknamed Platicur, as a novel photoactivated chemotherapeutic agent releases photoactive curcumin and an active platinum(II) species upon irradiation with visible light. The hydrolytic instability of free curcumin reduces upon binding to platinum(II). Interactions of 1 with 5'-GMP and ct-DNA indicated formation of platinum-bound DNA adducts upon exposure to visible light (λ=400-700 nm). It showed apoptotic photocytotoxicity in cancer cells (IC50 ≈ 15 μM), thus forming (⋅)OH, while remaining passive in the darkness (IC50 >200 μM). A comet assay and platinum estimation suggest Pt-DNA crosslink formation. The fluorescence microscopic images showed cytosolic localization of curcumin, thus implying possibility of dual action as a chemo- and phototherapeutic agent.

New Designs for Phototherapeutic Transition Metal Complexes

“…This results in the release of a ligand and generation of reactive species, which can both contribute to the therapeutic effect . Complexes with different metals/configuration, including a Pt II ‐curcumin derivative, have also been investigated for photosubstitution reactions …”

“…[21] Complexes with different metals/ configuration, including a Pt II -curcumin derivative, have also been investigated for photosubstitution reactions. [28] 3) Bioactive ligand release: Several complexes based on Mn I , Re I and Cr III centres can release, upon irradiation, small bioactive molecules such as NO [29] and CO. [30] Ru II complexes acting as photocages for enzyme inhibitors [31] or neurotransmitters [32] have also been investigated. 4) Ligand photocleavage: For this class of complexes, photoactivation is ligand-centred and results in the formation…”

A Platinum(II) Complex of Heptamethine Cyanine for Photoenhanced Cytotoxicity and Cellular Imaging in Near‐IR Light

“…Near-IR light-triggered uncaging of C4'-amine-substitued cyanine analogues was recently demonstrated by Schnermann and co-workers. [16] This finding,coupled with the observations suggesting that the Pt II À Obonds are photolabile, [11] prompted us to examine the photodegradation pathways of 1.W e performed the stability studies in solvents relevant to cellculture settings,t hat is,1 %D MSO in PBS or DMEM at biological pH of 7.4. Thephotoreactivity of 1 and IR797-acac was demonstrated by the rapid decrease in absorbance at 790 nm and ac oncomitant gradual increase at 410 nm when exposed to near-IR light (Figure 1b;Supporting Information, Figure S10).…”

Supramolecular Nanofibers of Curcumin for Highly Amplified Radiosensitization of Colorectal Cancers to Ionizing Radiation

“…In this article, we report for the first time that supramolecular nanomaterials can serve as an excellent nanoplatform to develop superior radiosensitizers. Curcumin, a polyphenol from the rhizomes of curcuma longa, was selected as the model drug in this work, as it is in clinical use and there have been several studies demonstrating that curcumin has potential radiosensitization effect. According to the literature, however, the SER10 values of curcumin or currently reported curcumin‐based nanoformulations are no more than 1.6 in various kinds of cancer cells .…”