Chloroform Extract of Rasagenthi Mezhugu, a Siddha Formulation, as an Evidence-Based Complementary and Alternative Medicine for HPV-Positive Cervical Cancers

Rasagenthi Mezhugu (RGM) is a herbomineral formulation in the Siddha system of traditional medicine and is prescribed in the southern parts of India as a remedy for all kinds of cancers. However, scientific evidence for its therapeutic efficacy in cervical cancer is lacking, and it contains heavy metals. To overcome these limitations, RGM was extracted, and the fractions were tested on HPV-positive cervical cancer cells, ME-180 and SiHa. The extracts, free from the toxic heavy metals, affected the viability of both the cells. The chloroform fraction (cRGM) induced DNA damage and apoptosis. Mitochondria-mediated apoptosis was indicated. Though both the cells responded to the treatment, ME-180 was more responsive. Thus, this study brings up scientific evidence for the efficacy of RGM against the HPV-mediated cervical cancer cells and, if the toxic heavy metals are the limitation in its use, cRGM would be a suitable candidate as evidence-based complementary and alternative medicine for HPV-positive cervical cancers

Induction of Redox-Mediated Cell Death in ER-Positive and ER-Negative Breast Cancer Cells by a Copper(II)-Phenolate Complex: An In Vitro and In Silico Study

This research was aimed at finding the cytotoxic potential of the mixed ligand copper(II) complex [Cu(tdp)(phen)](ClO4)—where H(tdp) is the tetradentate ligand 2-[(2-(2-hydroxyethylamino)-ethylimino)methyl]phenol, and phen is 1,10-phenanthroline—to two genotypically different breast cancer cells, MCF-7 (p53+ and ER+) and MDA-MB-231 (p53- and ER-). The complex has been already shown to be cytotoxic to ME180 cervical carcinoma cells. The special focus in this study was the induction of cell death by apoptosis and necrosis, and its link with ROS. The treatment brought about nuclear fragmentation, phosphatidylserine externalization, disruption of mitochondrial trans-membrane potential, DNA damage, cell cycle arrest at sub-G1 phase, and increase of ROS generation, followed by apoptotic death of cells during early hours and a late onset of necrosis in the cells surviving the apoptosis. The efficacy of the complex against genotypically different breast cancer cells is attributed to a strong association through p53-mitochondrial redox—cell cycle junction. The ADMET properties and docking of the complex at the active site of Top1 are desirable attributes of a lead molecule for development into a therapeutic. Thus, it is shown that the copper(II)–phenolate complex[Cu(tdp)(phen)]+ offers potential to be developed into a therapeutic for breast cancers in general and ER-negative ones in particular

Cytotoxic Property of Surfactant-Cobalt(III) Complexes on a Human Breast Cancer Cell Line

The cancer chemotherapeutic potential of surfactant-cobalt(III) complexes, cis-[Co(bpy)(2)(C14H29NH2)Cl](ClO4)(2) center dot 3 H2O (1) and cis-[Co(phen)(2)(C14H29NH2)Cl](ClO4)(2) center dot 3 H2O (2) (bpy 2,2 '-bipyridine, phen 1,10-phenanthroline) on MCF-7 breast cancer cell was determined adopting MTT assay and specific staining techniques. The complexes affected the viability of the cells significantly and the cells succumbed to apoptosis as seen in the changes in the nuclear morphology and cytoplasmic features. Since the complex 2 appeared to be more potent, further assays were carried out on the complex 2. Single-cell electrophoresis indicated DNA damage. The translocation of phosphatidyl serine and loss of mitochondrial potential was revealed by annexin V-Cy3 staining and JC-1 staining respectively. Western blot analysis revealed up-regulation of pro-apoptotic p53 and down-regulation of anti-apoptotic Bcl-2 protein. Taken together, the surfactant-cobalt(III) complex 2 would be a potential candidate for further investigation for application as a chemotherapeutic for cancers in general and estrogen receptor-positive breast cancer in particular

Mixed Ligand Copper(II) Complexes of <i>N</i>,<i>N</i>-Bis(benzimidazol-2-ylmethyl)amine (BBA) with Diimine Co-Ligands: Efficient Chemical Nuclease and Protease Activities and Cytotoxicity

A series of mononuclear mixed ligand copper­(II) complexes [Cu­(bba)­(diimine)]­(ClO₄)₂ <b>1</b>–<b>4</b>, where bba is <i>N</i>,<i>N</i>-bis­(benzimidazol-2-ylmethyl)­amine and diimine is 2,2′-bipyridine (bpy) (<b>1</b>), 1,10-phenanthroline (phen) (<b>2</b>), 5,6-dimethyl-1,10-phenanthroline (5,6-dmp) (<b>3</b>), or dipyrido­[3,2-<i>d</i>:2′,3′-<i>f</i>]­quinoxaline (dpq) (<b>4</b>), have been isolated and characterized by analytical and spectral methods. The coordination geometry around copper­(II) in <b>2</b> is described as square pyramidal with the two benzimidazole nitrogen atoms of the primary ligand bba and the two nitrogen atoms of phen (<b>2</b>) co-ligand constituting the equatorial plane and the amine nitrogen atom of bba occupying the apical position. In contrast, the two benzimidazole nitrogen atoms and the amine nitrogen atom of bba ligand and one of the two nitrogen atoms of 5,6-dmp constitute the equatorial plane of the trigonal bipyramidal distorted square based pyramidal (TBDSBP) coordination geometry of <b>3</b> with the other nitrogen atom of 5,6-dmp occupying the apical position. The structures of <b>1</b>–<b>4</b> have been optimized by using the density functional theory (DFT) method at the B3LYP/6-31G­(d,p) level. Absorption spectral titrations with Calf Thymus (CT) DNA reveal that the intrinsic DNA binding affinity of the complexes depends upon the diimine co-ligand, dpq (<b>4</b>) > 5,6-dmp (<b>3</b>) > phen (<b>2</b>) > bpy (<b>1</b>). The DNA binding affinity of <b>4</b> is higher than <b>2</b> revealing that the π-stacking interaction of the dpq ring in between the DNA base pairs with the two bzim moieties of the bba ligand stacked along the DNA surface is more intimate than that of phen. The complex <b>3</b> is bound to DNA more strongly than <b>1</b> and <b>2</b> through strong hydrophobic interaction of the methyl groups on 5,6-positions of the phen ring in the DNA grooves. The extent of the decrease in relative emission intensities of DNA-bound ethidium bromide (EB) upon adding the complexes parallels the trend in DNA binding affinities. The large enhancement in relative viscosity of DNA upon binding to <b>3</b> and <b>4</b> supports the DNA binding modes proposed. Interestingly, the 5,6-dmp complex <b>3</b> is selective in exhibiting a positive induced CD band (ICD) upon binding to DNA suggesting that it induces a B to A conformational change. In contrast, <b>2</b> and <b>4</b> show induced CD responses indicating their involvement in strong DNA binding. Interestingly, only the dpq complex <b>4</b>, which displays the strongest DNA binding affinity and is efficient in cleaving DNA in the absence of an activator with a rate constant of 5.8 ± 0.1 h^–1, which is higher than the uncatalyzed rate of DNA cleavage. All the complexes exhibit oxidative DNA cleavage ability, which varies as <b>4</b> > <b>2</b> > <b>3</b> > <b>1</b> (ascorbic acid) and <b>3</b> > <b>2</b> > <b>4</b> > <b>1</b> (H₂O₂). Also, the complexes cleave the protein bovine serum albumin in the presence of H₂O₂ as an activator with the cleavage ability varying in the order <b>3</b> > <b>4</b> > <b>2</b> > <b>1</b>. The highest efficiency of <b>3</b> to cleave both DNA and protein in the presence of H₂O₂ is consistent with its strong hydrophobic interaction with the biopolymers. The IC₅₀ values of <b>1</b>–<b>4</b> against cervical cancer cell lines (SiHa) are almost equal to that of cisplatin, indicating that they have the potential to act as effective anticancer drugs in a time-dependent manner. The morphological assessment data obtained by using acridine orange/ethidium bromide (AO/EB) and Hoechst 33258 staining reveal that <b>3</b> induces apoptosis much more effectively than the other complexes. Also, the alkaline single-cell gel electrophoresis study (comet assay) suggests that the same complex induces DNA fragmentation more efficiently than others

Mixed Ligand Copper(II) Complexes of <i>N</i>,<i>N</i>-Bis(benzimidazol-2-ylmethyl)amine (BBA) with Diimine Co-Ligands: Efficient Chemical Nuclease and Protease Activities and Cytotoxicity

A series of mononuclear mixed ligand copper­(II) complexes [Cu­(bba)­(diimine)]­(ClO₄)₂ <b>1</b>–<b>4</b>, where bba is <i>N</i>,<i>N</i>-bis­(benzimidazol-2-ylmethyl)­amine and diimine is 2,2′-bipyridine (bpy) (<b>1</b>), 1,10-phenanthroline (phen) (<b>2</b>), 5,6-dimethyl-1,10-phenanthroline (5,6-dmp) (<b>3</b>), or dipyrido­[3,2-<i>d</i>:2′,3′-<i>f</i>]­quinoxaline (dpq) (<b>4</b>), have been isolated and characterized by analytical and spectral methods. The coordination geometry around copper­(II) in <b>2</b> is described as square pyramidal with the two benzimidazole nitrogen atoms of the primary ligand bba and the two nitrogen atoms of phen (<b>2</b>) co-ligand constituting the equatorial plane and the amine nitrogen atom of bba occupying the apical position. In contrast, the two benzimidazole nitrogen atoms and the amine nitrogen atom of bba ligand and one of the two nitrogen atoms of 5,6-dmp constitute the equatorial plane of the trigonal bipyramidal distorted square based pyramidal (TBDSBP) coordination geometry of <b>3</b> with the other nitrogen atom of 5,6-dmp occupying the apical position. The structures of <b>1</b>–<b>4</b> have been optimized by using the density functional theory (DFT) method at the B3LYP/6-31G­(d,p) level. Absorption spectral titrations with Calf Thymus (CT) DNA reveal that the intrinsic DNA binding affinity of the complexes depends upon the diimine co-ligand, dpq (<b>4</b>) > 5,6-dmp (<b>3</b>) > phen (<b>2</b>) > bpy (<b>1</b>). The DNA binding affinity of <b>4</b> is higher than <b>2</b> revealing that the π-stacking interaction of the dpq ring in between the DNA base pairs with the two bzim moieties of the bba ligand stacked along the DNA surface is more intimate than that of phen. The complex <b>3</b> is bound to DNA more strongly than <b>1</b> and <b>2</b> through strong hydrophobic interaction of the methyl groups on 5,6-positions of the phen ring in the DNA grooves. The extent of the decrease in relative emission intensities of DNA-bound ethidium bromide (EB) upon adding the complexes parallels the trend in DNA binding affinities. The large enhancement in relative viscosity of DNA upon binding to <b>3</b> and <b>4</b> supports the DNA binding modes proposed. Interestingly, the 5,6-dmp complex <b>3</b> is selective in exhibiting a positive induced CD band (ICD) upon binding to DNA suggesting that it induces a B to A conformational change. In contrast, <b>2</b> and <b>4</b> show induced CD responses indicating their involvement in strong DNA binding. Interestingly, only the dpq complex <b>4</b>, which displays the strongest DNA binding affinity and is efficient in cleaving DNA in the absence of an activator with a rate constant of 5.8 ± 0.1 h^–1, which is higher than the uncatalyzed rate of DNA cleavage. All the complexes exhibit oxidative DNA cleavage ability, which varies as <b>4</b> > <b>2</b> > <b>3</b> > <b>1</b> (ascorbic acid) and <b>3</b> > <b>2</b> > <b>4</b> > <b>1</b> (H₂O₂). Also, the complexes cleave the protein bovine serum albumin in the presence of H₂O₂ as an activator with the cleavage ability varying in the order <b>3</b> > <b>4</b> > <b>2</b> > <b>1</b>. The highest efficiency of <b>3</b> to cleave both DNA and protein in the presence of H₂O₂ is consistent with its strong hydrophobic interaction with the biopolymers. The IC₅₀ values of <b>1</b>–<b>4</b> against cervical cancer cell lines (SiHa) are almost equal to that of cisplatin, indicating that they have the potential to act as effective anticancer drugs in a time-dependent manner. The morphological assessment data obtained by using acridine orange/ethidium bromide (AO/EB) and Hoechst 33258 staining reveal that <b>3</b> induces apoptosis much more effectively than the other complexes. Also, the alkaline single-cell gel electrophoresis study (comet assay) suggests that the same complex induces DNA fragmentation more efficiently than others

Surfactant–copper(II) Schiff base complexes: synthesis, structural investigation, DNA interaction, docking studies, and cytotoxic activity

<div><p>A series of surfactant–copper(II) Schiff base complexes (<b>1–6</b>) of the general formula, [Cu(sal-R₂)₂] and [Cu(5-OMe-sal-R₂)₂], {where, sal = salicylaldehyde, 5-OMe-sal = 5-methoxy- salicylaldehyde, and R₂ = dodecylamine (DA), tetradecylamine (TA), or cetylamine (CA)} have been synthesized and characterized by spectroscopic, ESI-MS, and elemental analysis methods. For a special reason, the structure of one of the complexes (<b>2</b>) was resolved by single crystal X-ray diffraction analysis and it indicates the presence of a distorted square-planar geometry in the complex. Analysis of the binding of these complexes with DNA has been carried out adapting UV-visible-, fluorescence-, as well as circular dichroism spectroscopic methods and viscosity experiments. The results indicate that the complexes bind via minor groove mode involving the hydrophobic surfactant chain. Increase in the length of the aliphatic chain of the ligands facilitates the binding. Further, molecular docking calculations have been performed to understand the nature as well as order of binding of these complexes with DNA. This docking analysis also suggested that the complexes interact with DNA through the alkyl chain present in the Schiff base ligands via the minor groove. In addition, the cytotoxic property of the surfactant–copper(II) Schiff base complexes have been studied against a breast cancer cell line. All six complexes reduced the visibility of the cells but complexes 2, 3, 5, and 6 brought about this effect at fairly low concentrations. Analyzed further, but a small percentage of cells succumbed to necrosis. Of these complexes (<b>6</b>) proved to be the most efficient aptotoxic agent.</p></div