Renu Sankar

Origanum vulgare mediated biosynthesis of silver nanoparticles for its antibacterial and anticancer activity

In the present study, we achieved silver nanoparticles using the aqueous extract of Origanum vulgare (Oregano) by reducing 1mM silver nitrate (AgNO3) solution. The green synthesized silver nanoparticles were characterized by high throughput techniques like UV-vis spectroscopy, Fourier infrared spectroscopy (FT-IR), field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and dynamic light scattering measurements. Morphologically, the nanoparticles were found to be spherical with an average particle size distribution of 136±10.09nm. FT-IR spectral analysis illustrates the occurrence of possible biomolecules required for the reduction of silver ions. The obtained nanoparticles were stable (-26±0.77mV) at ambient temperature. The biosynthesized nanoparticles were found to be impressive in inhibiting human pathogens. The green synthesized silver nanoparticles showed dose dependent response against human lung cancer A549 cell line (LD50 - 100μg/ml).

Green synthesis of colloidal copper oxide nanoparticles using Carica papaya and its application in photocatalytic dye degradation.

Copper oxide (CuO) nanoparticles were synthesized by treating 5 mM cupric sulphate with Carica papaya leaves extract. The kinetics of the reaction was studied using UV-visible spectrophotometry. An intense surface Plasmon resonance between 250-300 nm in the UV-vis spectrum clearly reveals the formation of copper oxide nanoparticles. The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) exhibited that the green synthesized copper oxide nanoparticles are rod in shape and having a mean particle size of 140 nm, further negative zeta potential disclose its stability at -28.9 mV. The Fourier-transform infrared (FTIR) spectroscopy results examined the occurrence of bioactive functional groups required for the reduction of copper ions. X-ray diffraction (XRD) spectra confirmed the copper oxide nanoparticles crystalline nature. Furthermore, colloidal copper oxide nanoparticles effectively degrade the Coomassie brilliant blue R-250 dye beneath the sunlight.

Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles

The design, synthesis, characterization and application of biologically synthesized nanomaterials have become a vital branch of nanotechnology. There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on an eco-friendly process for rapid synthesis of copper oxide nanoparticles using Ficus religiosa leaf extract as reducing and protecting agent. The synthesized copper oxide nanoparticles were confirmed by UV-vis spectrophotometer, absorbance peaks at 285 nm. The copper oxide nanoparticles were analyzed with field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) spectrum. The FE-SEM and DLS analyses exposed that copper oxide nanoparticles are spherical in shape with an average particle size of 577 nm. FT-IR spectral analysis elucidates the occurrence of biomolecules required for the reduction of copper oxide ions. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The XRD pattern revealed that synthesized nanoparticles are crystalline in nature. Further, biological activities of the synthesized nanoparticles were confirmed based on its stable anti-cancer effects. The apoptotic effect of copper oxide nanoparticles is mediated by the generation of reactive oxygen species (ROS) involving the disruption of mitochondrial membrane potential (Δψm) in A549 cells. The observed characteristics and results obtained in our in vitro assays suggest that the copper nanoparticles might be a potential anticancer agent.

Romidepsin induces cell cycle arrest, apoptosis, histone hyperacetylation and reduces matrix metalloproteinases 2 and 9 expression in bortezomib sensitized non-small cell lung cancer cells

Histone deacetylase (HDAC) inhibitors have been proven to be effective therapeutic agents to kill cancer cells through inhibiting HDAC activity or altering the structure of chromatin. We recently reported that chemotherapy by the HDAC inhibitor, romidepsin activates the anti- apoptotic transcription factor NF-κB in A549 non-small cell lung cancer (NSCLC) cells and fails to induce significant levels of apoptosis. We also demonstrated that NF-κB inhibition with proteasome inhibitor bortezomib enhanced HDAC inhibitor induced mitochondrial injury and sensitize A549 NSCLC cells to apoptosis through the generation of reactive oxygen species. In this study, we investigate whether combined treatment with romidepsin and bortezomib would induce apoptosis in A549 NSCLC cells by activating cell cycle arrest, enhanced generation of p21 and p53, down-regulation of matrix metalloproteinases (MMPs) 2,9 also altering the acetylation status of histone proteins. Our data show that combination of romidepsin and bortezomib caused cell cycle arrest at Sub G0-G1 transition, up-regulation of cell cycle protein p21 and tumour suppressor protein p53. In addition, romidepsin down-regulated the expression of MMP-2,9 and hyperacetylation of histone H3 and H4 in bortezomib sensitised A549 NSCLC cells. From this study we concluded that romidepsin and bortezomib cooperatively inhibit A549 NSCLC cell proliferation by altering the histone acetylation status, expression of cell cycle regulators and MMPs. Romidepsin along with bortezomib might be an effective treatment approach for A549 NSCLC cells.

Fabrication of nano-silver particles using Cymodocea serrulata and its cytotoxicity effect against human lung cancer A549 cells line

The present study reports, green synthesis of bioactive silver nanoparticles (AgNPs) under different temperature (60°C, room temperature and 4° refrigerator) using the aqueous extract of sea grass Cymodocea serrulata as a potential bioreductant. Increased temperature fabricates more AgNPs compare to room temperature and refrigerator condition. At first the reduction of Ag(+) ions were confirmed through color change which produces an absorbance spectra at 420nm in UV-Visible spectrophotometer. Additionally various exclusive instrumentations such as X-ray diffraction (XRD), Dynamic light scattering (DLS), scanning electron microscope (SEM) analysis and Transmission electron microscope (TEM) were authorizes the biosynthesis and physio-chemical characterization of AgNPs. From Fourier transform infrared spectroscopy (FTIR) analysis, it was identified that the water soluble fractions of the sea grass mainly responsible for reduction of ionic silver (Ag(+)) into (Ag(0)) nano-ranged particles and also they act as stabilizing agent to sustain the durability of NPs for long period of time. Further, synthesized AgNPs shows potential cytotoxicity against human lung cancer A549 cells (LD50-100μg/ml). The overall results suggest that C. serrulata is a valuable bioresource to generate rapid and eco-friendly bioactive AgNPs towards cancer therapy.

Blocking NF-κB sensitizes non-small cell lung cancer cells to histone deacetylase inhibitor induced extrinsic apoptosis through generation of reactive oxygen species.

NF-κB signalling is one of the main cell survival pathways that attenuate the anticancer efficacy of therapeutic drugs. Previous studies demonstrated that the histone deacetylase (HDAC) inhibitor induces apoptosis in some malignancies through multiple mechanisms including up-regulation of death receptors, disruption of Hsp90 function and generation of reactive oxygen species (ROS). However, HDAC inhibitor also induces a cell survival signal through NF-κB activation. In this report, we found that romidepsin, a class I HDAC inhibitor, induces NF-κB activation in A549 non-small-cell lung cancer (NSCLC) cells. We also found that inhibition of A549 cells with bortezomib (proteasome inhibitor) has blocked IκB degradation that leads to the loss of NF-κB activation and translocation which enhanced the romidepsin induced mitochondrial injury and sensitizes NSCLC cells to apoptosis. Romidepsin significantly enhances NF-κB reporter gene transcription and these effects were inhibited by bortezomib as determined by reporter gene assay. Consistently, the combined exposure of romidepsin and bortezomib reversed the effects on IκB degradation as evident with IL-8, p50 and p65 (NF-κB) expression. Apoptosis was markedly sensitized with greater ROS generation and more cell death in A549 cell lines. These events are most closely related in that bortezomib prevents the romidepsin mediated RelA acetylation and NF-κB activation, resulting in caspase activation. A strategy of blocking NF-κB activation to enhance HDAC inhibitor activity warrants further attention in NSCLC cells.

Inhibition of pathogenic bacterial growth on excision wound by green synthesized copper oxide nanoparticles leads to accelerated wound healing activity in Wistar Albino rats

An impaired wound healing is one of the major health related problem in diabetic and non-diabetic patients around the globe. The pathogenic bacteria play a predominant role in delayed wound healing, owing to interaction in the wound area. In our previous work we developed green chemistry mediated copper oxide nanoparticles using Ficus religiosa leaf extract. In the present study we make an attempt to evaluate the anti-bacterial, and wound healing activity of green synthesized copper oxide nanoparticles in male Wistar Albino rats. The agar well diffusion assay revealed copper oxide nanoparticles have substantial inhibition activity against human pathogenic strains such as Klebsiella pneumoniae, Shigella dysenteriae, Staphylococcus aureus, Salmonella typhimurium and Escherichia coli, which were responsible for delayed wound healing process. Furthermore, the analyses results of wound closure, histopathology and protein profiling confirmed that the F. religiosa leaf extract tailored copper oxide nanoparticles have enhanced wound healing activity in Wistar Albino rats.Graphical Abstract

Biocompatibility and biodistribution of suberoylanilide hydroxamic acid loaded poly (DL-lactide-co-glycolide) nanoparticles for targeted drug delivery in cancer.

The biodegradable polymeric nanoparticles have been potentially used to carry various chemotherapy agents into cancer cells for targeted drug delivery. Conversely, the biodistribution and toxic effects of these drug-loaded nanoparticles have raised some concerns. In the present study, we tried to explore the prospective histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) loaded poly (DL-lactide-co-glycolide) (PLGA) nanoparticles biocompatibility and biodistribution in animal system. The biocompatibility of SAHA loaded PLGA nanoparticles were evaluated through hemolysis, biochemical and histopathological analysis. The analysis results showed SAHA loaded PLGA nanoparticles has good hemocompatibility, not at all an elevation of blood biochemical parameters and no specific remarkable tissues changes in liver, kidney, lung, and heart as compared with control. The orally administered SAHA loaded PLGA nanoparticles distributions in various organs were confirmed using spectrofluorometry and fluorescence microscope. The results shows nanoparticles were remained detectable in the liver, kidney, heart and lung tissues after 3days. Moreover, the SAHA loaded PLGA nanoparticles are actively taken up in the A549 lung cancer cells. The overall results conclude that the histone deacetylase inhibitor SAHA loaded PLGA nanoparticles is biocompatible and actively distributed various organs in the animal system. The biocompatible SAHA loaded PLGA nanoparticles may be a suitable anticancer agent in the near feature.

Nanostructured delivery system for Suberoylanilide hydroxamic acid against lung cancer cells

With the objective to provide a potential approach for the treatment of lung cancer, nanotechnology based Suberoylanilide hydroxamic acid (SAHA)-loaded Poly-d, l-lactide-co glycolide (PLGA) nanoparticles have been formulated using the nanoprecipitation technique. The acquired nanoparticles were characterized by various throughput techniques and the analyses showed the presence of smooth and spherical shaped SAHA-loaded PLGA nanoparticles, with an encapsulation efficiency of 44.8% and a particle size of 208nm. The compatibility between polymer and drug in the formulation was tested using FT-IR, Micro-Raman spectrum and DSC thermogram analyses, revealing a major interaction between the drug and polymer. The in vitro drug release from the SAHA-loaded PLGA nanoparticles was found to be biphasic with an initial burst followed by a sustained release for up to 50h. In experiments using the lung cancer cell line A549, SAHA-loaded PLGA nanoparticles demonstrated a superior antineoplastic activity over free SAHA. In conclusion, SAHA-loaded PLGA nanoparticles may be a useful novel approach for the treatment of lung cancer.

Unraveling the caspase-mediated mechanism for phloroglucinol-encapsulated starch biopolymer against the breast cancer cell line MDA-MB-231

The main objective of the study is to decipher the mechanism underlying the anticancer activity of phloroglucinol-encapsulated starch biopolymer against the breast cancer cell line MDA-MB-231. An MTT assay confirmed that MDA-MB-231 cells are highly susceptible to treatment with the biopolymer in a dose-dependent manner. Morphological evidence by fluorescence staining revealed chromatin condensation, nuclear beading and loss of mitochondrial membrane potential. DNA fragmentation and cell cycle analysis confirm the progression of apoptosis in the MDA-MB-231 breast cancer cell line. The semi-quantitative RT-PCR showed increased levels of pro-apoptotic genes such as those for caspase-3, 8 and 9. Western blotting analysis was done to substantiate the caspase-3 and 8 expressions in an efficient execution of apoptosis. To conclude, the controlled release of the polyphenolic compound phloroglucinol from starch induces cytotoxicity against the MDA-MB-231 breast cancer cell line.