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.