Background: Chemotherapy is currently the most utilized treatment for cancer. Therapeutic potential of metal complexes in cancer therapy has attracted a lot of interest. The mechanisms of action of most organometallic complexes are poorly understood.
Objective: This study was designed to explore the mechanisms governing the anti-proliferative effect of the free ligand N1,N6-bis((2-hydroxynaphthalin-1-yl)methinyl)) adipohydrazone (H2L) and its complexes of Mn(II), Co(II), Ni(II) and Cu(II).
Methods: Cells were exposed to H2L or its metal complexes where cell viability determined by MTT assay. Cell cycle was analysed by flow cytometry. In addition, qRT-PCR was used to monitor the expression of Bax and Bcl-2. Moreover, molecular docking was carried out to find the potentiality of Cu(II) complex as an inhibitor of Adenosine Deaminase (ADA). ADA, Superoxide Dismutase (SOD) and reduced Glutathione (GSH) levels were measured in the most affected cancer cell line.
Results: The obtained results demonstrated that H2L and its Cu(II) complex exhibited a strong cytotoxic activity compared to other complexes against HepG2 cells (IC50=4.14±0.036μM/ml and 3.2±0.02μM/ml), respectively. Both H2L and its Cu(II) complex induced G2/M phase cell cycle arrest in HepG2 cells. Additionally, they induced apoptosis in HepG2 cells via upregulation of Bax and downregulation of Bcl-2. Interestingly, the activity of ADA was decreased by 2.8 fold in HepG2 cells treated with Cu(II) complex compared to untreated cells. An increase of SOD activity and GSH level in HepG2 cells compared to control was observed.
Conclusion: The results concluded that Cu(II) complex of H2L induced apoptosis in HepG2 cells. Further studies are needed to confirm its anti-cancer effect in vivo.