Andrographolide coordinated ruthenium(II) arene complexes: Synthesis, spectral characterization, antioxidant assays, in vitro cytotoxicity, and apoptosis investigation

Abstract

Two new ruthenium(II)-complexes, [Ru(Ang)((benzene)Cl₂] (RuB-Ang) and [Ru(Ang)((p-cymene)Cl₂] (RuC-Ang), were synthesized using andrographolide (Ang) as a ligand with [RuCl₂(arene)]₂ (arene = benzene or p-cymene) and characterized by various spectroscopic techniques. These techniques ascertained the formation of the complexes. An assessment of the antioxidant activity of the compounds indicated better scavenging activity against ABTS^•+, DPPH^•, O²⁻, NO^• and OH⁻ radicals. The cytotoxic activities of RuB-Ang and RuC-Ang have been evaluated against A549 (human lung) and HeLa (human cervical) cancer cell lines. The complexes exhibited superior anticancer activity to cisplatin and was non-toxic towards human umbilical vein endothelial (HUVEC) cells. The morphological changes of the HeLa and A549 cells with the complexes have been studied by AO-EB and DAPI staining methods. The cytotoxic nature of the compounds was RuC-Ang > RuB-Ang > cisplatin > ligand.

KEYWORDS:

• Andrographolide
• Ru(II) complexes
• Antioxidant assays
• Anticancer activity
• Staining assay

Disclosure Statement

The authors declare no competing financial interest.

Acknowledgements

Dr. G. K greatly acknowledges Tamil Nadu State Council for Science and Technology for providing Young Scientist Fellowship Scheme project fellowship (TNSCST/YSFS/VR/19/2021-2022) and Karpagam Academy of Higher Education Management for providing research support. The author Dr. S. P gratefully acknowledges Department of Science and Technology, India for the Women Scientist Scheme – WOS (A) Fellowship, Department of Science and Technology, New Delhi, India [Grant No. SR/WOS(A)/CS-147/2021].