The heme protein cytochrome c (Cyt c) plays pivotal roles in cellular life and death processes. In the respiratory chain of mitochondria, it serves as an electron transfer protein, contributing to the proliferation of healthy cells. In the cell cytoplasm, it activates intrinsic apoptosis to terminate damaged cells. Insight into these mechanisms and the associated physicochemical properties and biomolecular interactions of Cyt c informs on the anticancer therapeutic potential of the protein, especially in its ability to subvert the current limitations of small molecule-based chemotherapy. In this review, we explore the development of Cyt c as an anticancer drug by identifying cancer types that would be receptive to the cytotoxicity of the protein and factors that can be finetuned to enhance its apoptotic potency. To this end, some information is obtained by characterizing known drugs that operate, in part, by triggering Cyt c induced apoptosis. The application of different smart drug delivery systems is surveyed to highlight important features for maintaining Cyt c stability and activity and improving its specificity for cancer cells and high drug payload release while recognizing the continuing limitations. This work serves to elucidate on the optimization of the strategies to translate Cyt c to the clinical market.

The development of novel naphthalene-modified metallosalens incorporating Pt(II) and Pd(II) presents a promising approach to addressing limitations in cancer therapies. These metallosalens were synthesized and characterized using single crystal X-ray diffraction (sc-XRD), UV-vis spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and C, H, N elemental analysis. Their strong metal coordination and enhanced electronic interactions, stemming from π-conjugated aromatic structures, improved their DNA-binding affinity and cytotoxic efficacy. Biological assays confirmed significant cytotoxicity in A375 (melanoma) and H292 (nonsmall cell lung cancer) cell lines, while demonstrating minimal toxicity toward HSAEC healthy lung cells. PtL1 and PtL2 exhibited superior activity, inducing apoptosis with high selectivity for cancer cells, as validated by Incucyte Caspase-3/7 Green Dye assays. These findings highlight the potential of naphthalene-modified metallosalens as broad-spectrum cancer therapies, balancing efficacy with reduced off-target effects, and underscore the importance of ligand design and metal coordination in advancing next-generation chemotherapeutics.

In this study, a series of (Z)- and (E)-2-substituted-3-ferrocene-acrylonitrile derivatives were synthesized, characterized, and evaluated in vitro for their anticancer and anti-migration properties. The compounds were synthesized via the Knoevenagel condensation of the appropriate benzyl cyanide or benzoyl acetonitrile with ferrocenecarboxaldehyde 1, producing isolated yields of 99 to 23%. The structures of the compounds were analyzed using IR, ¹H NMR, ¹³C{¹H} NMR, GC-MS, and UV/Vis spectroscopic methods. Single-crystal X-ray diffraction analysis of representative compounds 21, 27, and 29 demonstrated that the geometry of the double bond was that of the (Z)-isomer. For representative compound 33, the geometry of the double bond was that of the (E)-isomer. Additionally, the electrochemistry of the compounds was investigated using cyclic voltammetry. The cytotoxic and anti-migratory effects of these compounds were evaluated in the MCF-7 and MDA-MB-231 breast cancer cell lines, providing insight into the structure–activity relationships. Preliminary investigations of their anticancer activity revealed that several compounds exhibit moderate antiproliferative effects on cancer cell lines, with GI₅₀ values ranging from 23 to 44 μM for the MCF-7 cell line and from 9 to 41 μM for the MDA-MB-231 cell line. Moreover, compound (Z)-25 inhibited 13% of the migration activity of the metastatic MDA-MB-231 cell line.