Comparative Study Of Cytotoxicity Research Articles

Dipicolinate‐Ruthenium‐NHC/trpy Complexes: Pincer Ligand Induced Hemilability of Dipicolinate and Enhancement of Cytotoxic Property

AbstractA ruthenium(II) aquo complex [Ru(dipic)(PPh3)2(OH2)], (1 A), bearing O,N,O‐coordinated 2,6‐dipicolinate was synthesized via reaction of [Ru(PPh3)3Cl2] with 2,6‐dipicolinic acid. Crystal structure of 1 A was determined. Utilizing 1 A as a synthon, three new complexes were synthesized. Reaction of 1 A with a bidentate NHC‐ligand, viz. 1‐methyl‐3‐(2′‐pyridyl)imidazole (IMeCN), afforded [Ru(dipic)(IMeCN)(PPh3)], (2 A). Similar reactions of 1 A with two pincer ligands, viz. 2,6‐bis(1′‐methyl imidazolyl)pyridine (IMeCNC) and 2,2′;6′,2“‐terpyridine (trpy), respectively yielded [Ru(dipic)(IMeCNC)(PPh3)], (3 A) and [Ru(dipic)(trpy)(PPh3)], (3 B). Structure of 2 A was optimized by DFT method. Structures of 3 A and 3 B were determined by X‐ray crystallography. In both 3 A and 3B the 2,6‐dipicolinate ligand was found to be N,O‐coordinated with one carboxy end remaining unbound to the metal center. Anticancer property of 2 A, 3 A and 3 B was studied and compared. Cytotoxicity of 3 A, studied against three selected cancer cell lines, viz. chronic myelogenous leukemia cell line (K562), hepatocellular carcinoma cell line (HepG2) and breast adenocarcinoma cell line (MCF7), was found to be the most promising. It displayed the best activity against K562, while it did not have any appreciable effect on its normal counterpart, viz. the human peripheral blood mononuclear cells (hPBMC). The comparative cytotoxicity studies indicated that presence of the C,N,C‐coordinated pincer NHC ligand in 3 A, together with presence of the free carboxylate end of N,O‐coordinated dipic ligand, are presumably responsible for its superior cytotoxic behavior.

Comparative Study of Cytotoxicity and Accumulation of Boron and Lithium-Containing Drugs in Skin Melanoma Cells In Vitro.

We studied cytotoxicity and accumulation of boron and lithium by cultured human fibroblasts and human and mouse skin melanoma cell cultures. The cytotoxicity of boron and lithium drugs was assessed by MTT tests in the boron and lithium concentration range of 10-640 μg/ml. Cell viability was significantly reduced after incubation with boron and lithium at concentrations >160 μg/ml. To assess accumulation of boron and lithium, the concentration of elements was measured using inductively coupled plasma atomic emission spectrometry. Melanoma cells more intensively accumulated lithium in comparison with boron. The results indicate the possibility of safe application of lithium salts in concentrations minimally required for successful neutron capture therapy.

Modes of Interactions with DNA/HSA Biomolecules and Comparative Cytotoxic Studies of Newly Synthesized Mononuclear Zinc(II) and Heteronuclear Platinum(II)/Zinc(II) Complexes toward Colorectal Cancer Cells.

A series of mono- and heteronuclear platinum(II) and zinc(II) complexes with 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine ligand were synthesized and characterized. The DNA and protein binding properties of [ZnCl2(terpytBu)] (C1), [{cis-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C2), [{trans-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C3), [{cis-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C4) and [{trans-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C5) (where terpytBu = 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine), were investigated by electronic absorption, fluorescence spectroscopic, and molecular docking methods. Complexes featuring transplatin exhibited lower Kb and Ksv constant values compared to cisplatin analogs. The lowest Ksv value belonged to complex C1, while C4 exhibited the highest. Molecular docking studies reveal that the binding of complex C1 to DNA is due to van der Waals forces, while that of C2-C5 is due to conventional hydrogen bonds and van der Waals forces. The tested complexes exhibited variable cytotoxicity toward mouse colorectal carcinoma (CT26), human colorectal carcinoma (HCT116 and SW480), and non-cancerous mouse mesenchymal stem cells (mMSC). Particularly, the mononuclear C1 complex showed pronounced selectivity toward cancer cells over non-cancerous mMSC. The C1 complex notably induced apoptosis in CT26 cells, effectively arrested the cell cycle in the G0/G1 phase, and selectively down-regulated Cyclin D.

In vitro anti-inflammatory and comparative cytotoxicity studies on methanolic extract of Enicostemma hyssopifolium

Enicostemma hyssopifolium is a perineal herb widely used as an antidiabetic agent in folklore medicine. The present work was focused on the assessment of its anti-inflammatory and cytotoxic properties. Its methanolic extract was evaluated for anti-inflammatory activity using murine monocytic macrophage RAW 264.7 cells, and screened for its cytotoxic property in different cancer cell lines. The methanolic extract was able to potentially inhibit the bacterial lipopolysaccharides-induced inflammatory response in RAW 264.7 cells. Results of the cytotoxicity studies revealed that the methanolic extract effectively induced the cytotoxicity at considerably lower concentration in MCF-7, A-549, and COLO-205 cell lines, while the viability of HeLa, CasKi, and HT-29 cells were inhibited at comparatively higher concentrations. Results thus indicated that E. hyssopifolium possessed potent anti-inflammatory and cytotoxic properties. This necessitates further exploration of bioactive phytochemical compounds responsible for these properties for therapeutic applications.

Divergent Responses of Hydrophilic CdSe and CdSe@CdS Core-Shell Nanocrystals in Apoptosis and In Vitro Cancer Cell Imaging: A Comparative Analysis.

With their distinctive core-shell design, core-shell nanocrystals have drawn interest in catalysis, medicinal research, and nanotechnology. These nanocrystals have a variety of characteristics and possible uses. The application of core-shell nanocrystals offers significant potential in increasing diagnostic and therapeutic approaches for cancer research in apoptosis and in vitro cancer cell imaging. In the present study, we investigated the fluorescence behavior of hydrophilic CdSe (core-only) and CdSe@CdS (core-shell) nanocrystals (NCs) and their potential in cancer cell imaging. The addition of a CdS coating to CdSe NCs increased the fluorescence intensity tenfold. The successful fabrication of core-shell CdSe@CdS nanocrystals was proven by a larger particle size (evaluated via DLS and TEM) and their XRD pattern and surface morphology compared to CdSe (core-only) NCs. When these NCs were used for bioimaging in MCF-7 and HEK-293 cell lines, they demonstrated excellent cellular uptake due to higher fluorescence intensity within cancerous cells than normal cells. Comparative cytotoxicity studies revealed that CdSe NCs were more toxic to all three cell lines (HEK-293, MCF-7, and HeLa) than CdSe@CdS core-shell structures. Furthermore, a decrease in mitochondrial membrane potential and intracellular ROS production supported NCs inducing oxidative stress, which led to apoptosis via the mitochondria-mediated pathway. Increased cytochrome c levels, regulation of pro-apoptotic gene expression (e.g., p53, Bax), and down-regulation of Bcl-2 all suggested cellular apoptosis occurred via the intrinsic pathway. Significantly, at an equivalent dose of core-shell NCs, core-only NCs induced more oxidative stress, resulting in increased apoptosis. These findings shed light on the role of a CdS surface coating in reducing free radical release, decreasing cytotoxicity, and improving fluorescence, advancing the field of cell imaging.

Comparative Study of Cytotoxicity and Antioxidant, Anti-Aging and Antibacterial Properties of Unfermented and Fermented Extract of Cornus mas L.

Due to the high demand for products that can help treat various skin conditions, the interest in plant extracts, which are a valuable source of phytochemicals, is constantly growing. In this work, the properties of extracts and ferments from Cornus mas L. and their potential use in cosmetic products were compared. For this purpose, their composition, antioxidant properties and cytotoxicity against skin cells, keratinocytes and fibroblasts were assessed in vitro. In addition, the ability to inhibit the activity of collagenase and elastase was compared, which enabled the assessment of their potential to inhibit skin aging. Microbiological analyses carried out on different bacterial strains were made in order to compare their antibacterial properties. The conducted analyses showed that both dogwood extract and ferment have antioxidant and anti-aging properties. In addition, they can have a positive effect on the viability of keratinocytes and fibroblasts and inhibit the proliferation of various pathogenic bacteria, which indicates their great potential as ingredients in skin care preparations. The stronger activity of the ferment compared to the extract indicates the legitimacy of carrying out the fermentation process of plant raw materials using kombucha in order to obtain valuable products for the cosmetics industry.

Fabrication of PLGA Nanoparticles Using Combination of PCL-PVA-PEG Copolymer as Surfactant: In-Vitro Characterization and Cytotoxicity Study

Objective: The present study aimed to fabricate Poly lactic acid co-glycolic acid (PLGA) nanoparticles loaded with resveratrol using a novel graft co-polymer surfactant named Soluplus®. Methods: The PLGA nanoparticles were prepared in the present study using polyvinyl caprolactam polyvinyl acetate polyethylene glycol amphiphilic graft copolymer named Soluplus® as surfactant through double emulsification and single emulsification-solvent evaporation method. The formulations were prepared successfully to encapsulate the drug resveratrol, and then evaluated for their particle size, polydispersity index, zeta potential, drug loading and the degree of entrapment of the drug. A scanning electron microscope was used to examine the morphology of the nanoparticles. In vitro drug release was assessed and, mathematical pharmacokinetic modelling was done to assess the release pattern. A comparative cytotoxicity study between free drug and prepared nanoparticles using MTT assay was carried out for cell viability evaluation. Uptake and internalization of nanoparticles were also studied using confocal fluorescence microscopy. Results: The results demonstrated successful fabrication of the PLGA nanoparticles using the Soluplus as polymer surfactant. The drug, polymer and the all the excipients were found to be compatible and did not indicate any interaction. The results also indicated the prepared nanoparticles (SF2) as suitable resveratrol delivery vehicle in terms of the compliant particle size (344.6 ±6.63 nm), polydispersity index (0.962), zeta potential (- 18.5±1.21), drug loading (18.94± 0.27%), the entrapment efficiency (39.62±0.17%) and drug release (75.13±0.17%). The shape and surface morphology of the formulated nanoparticles were found to be spherical and smooth. Cytotoxicity study also demonstrated significant reduction of cell viability by the nanoparticle compared to free resveratrol. The highest cytotoxicity of SF2 against MCF7 cell was found in 2000 nM concentration with 3.03±0.05 percent of cell viability. It was found that the percentage of growth inhibition was increasing with increasing concentration of SF2 and IC50 value of this assay was 108.94 μg/ml. Conclusion: It has been found that the Resveratrol loaded PLGA nanoparticles were successfully formulated and found to perform better in terms of efficacy and cytotoxicity.

Digitizing protocols into single reactors for the one-pot synthesis of nanomaterials

Digitizing protocols into single reactors for the one-pot synthesis of nanomaterials

An in-vitro quantitative investigation on the synergistic effect of capsaicin and 5-fluorouracil encapsulated into lipid nanocapsules to treat breast cancer

Background Breast cancer conventional therapeutics are effective; however, they encounter some limitations including multidrug resistance, the presence of pharmacological barriers, and non-selectivity which hinder their optimal therapeutic efficacy. Aim Overcoming such drawbacks necessitates the development of efficient drug vehicles including lipid-based nanoparticles. This study aimed to quantitatively investigate in-vitro the synergistic therapeutic effect of the novel combination of capsaicin and 5-fluorouracil (5-FU) encapsulated in lipid nanocapsules (LNCs). Method To this end, thorough physicochemical and in-vitro assessments on the breast cancer cell line (MCF-7) were done. The drug-loaded LNCs were characterized using DLS, TEM imaging, stability study, and in-vitro release study. Furthermore, the biological activity of the prepared LNCs was assessed by implementing comparative cytotoxicity studies as well as apoptosis, and cell cycle flow cytometric analyses. Results The developed nanoformulations were monodisperse with average particle size (PS) of 31, 43.8, and 127.3 nm for empty LNCs, Cap-LNCs, and 5-FU-LNCs, respectively, and with a surface charge of −35.4, −21.7 and −31.4 mV, respectively, reflecting good physical stability. The TEM micrographs revealed the spherical morphology of the drugs-loaded LNCs with comparable PS to that obtained by DLS. on the other hand, all the biological assessments confirmed the superior antiproliferative effect of the combined drug-loaded LNCs over their free drug counterparts. Conclusion Intriguingly, the study findings highlighted the potential synergistic activity of the drugs (capsaicin and 5-FU) and the extensive enhancement of their biological activity through incorporation into LNCs. Such promising results will pave the way to further novel combined nanoformulation in preclinical and clinical studies on breast cancer patients.

P07-38 Comparative cytotoxicity study of whole cigarette smoke condensates generated from heated tobacco products and 3R4F reference cigarette

Food-producing animals are infected by a number of ectoparasites that can result in production losses. Control of these parasites is largely based on the use of chemicals that are either applied topically to the skin or sometimes given parenterally. Most ectoparasiticides are neurotoxins, exerting their effect on the nervous system of the target parasite. As a result of frequent and inappropriate use, resistance of arthropods to the lethal effects of parasiticides has been reported in many parts of the world. Ectoparasiticides can also be toxic to mammals and restrictions are therefore applied to many of the compounds indicated for use in food-producing animals to ensure that unacceptable residues are not present in products intended for human consumption. Consequently many international organizations and countries have issued their own pesticide maximum residual limits in international trade.

Nisin and nisin-loaded nanoparticles: a cytotoxicity investigation

Objective Nisin is an antibacterial peptide with anticancer properties, but the main drawback is its rapid enzymatic degradation and limited permeation across the cell membrane. This research aims to overcome these drawbacks by developing nisin-loaded nanoparticles (NPN) with improved cytotoxic effects. Significance PLGA nanoparticles are one of the most effective biodegradable and biocompatible drug delivery carriers. In the present study, nisin-loaded nanoparticles showed enhanced anticancer effects. Methods NPN was prepared by a double emulsion solvent evaporation method and characterized for different parameters. The cytotoxic investigation of NPN was carried out on various cell lines, including A549, SW-620, HT-29, PC-3, MDA-MB-231, MCF-7, MiaPaca-2, and fR2 by sulforhodamine B (SRB) assay. Mechanistic investigation of cellular cytotoxicity was performed by using bright-field microscopy, DAPI staining, intracellular reactive oxygen species (ROS), changes in mitochondrial membrane potential (ΔΨm), Western blotting and cellular uptake study. A comparative cytotoxicity study of nisin and NPN was performed on normal breast epithelial cells (fR2). Results NPN showed spherical shape, 289.09 ± 3.63 nm particle size, and 63.37 ± 3.12% entrapment efficiency. NPN was more cytotoxic to the MDA-MB-231 cell line, showing higher nuclear fragmentation, ROS generation, depletion of ΔΨm, and enhanced intracellular uptake with apoptosis signs compared with nisin and with no cytotoxicity on normal cells. Conclusions The findings suggest that nisin delivery via PLGA nanoparticles can be used to treat cancer without significant effects on healthy cells.

Pd(II) and Pt(II) Pincer Complexes of a Benzothiazole-Appended Methylthioacetamide Ligand: Synthesis and in vitro Cytotoxicity

The condensation of 2-(benzothiazol-2-yl)aniline with 2-(methylthio)acetyl chloride affords a new representative of non-classical pincer-type ligands based on functionalized amides. This compound is shown to smoothly undergo direct cyclometalation under the action of a Pd(II) or Pt(II) precursor. The realization of the S,N,N-coordination in the resulting complexes through the deprotonated central amide unit and ancillary N- and S-donor groups is unequivocally confirmed by the NMR and IR spectroscopic data as well as X-ray diffraction analysis. The results of comparative cytotoxicity studies of the compounds obtained on several human cancer cell lines are presented.

2D Materials and Primary Human Dendritic Cells: A Comparative Cytotoxicity Study.

Human health can be affected by materials indirectly through exposure to the environment or directly through close contact and uptake. With the ever-growing use of 2D materials in many applications such as electronics, medical therapeutics, molecular sensing, and energy storage, it has become more pertinent to investigate their impact on the immune system. Dendritic cells (DCs) are highly important, considering their role as the main link between the innate and the adaptive immune system. By using primary human DCs, it is shown that hexagonal boron nitride (hBN), graphene oxide (GO) and molybdenum disulphide have minimal effects on viability. In particular, it is evidenced that hBN and GO increase DC maturation, while GO leads to the release of reactive oxygen species and pro-inflammatory cytokines. hBN and MoS2 increase T cell proliferation with and without the presence of DCs. hBN in particular does not show any sign of downstream T cell polarization. The study allows ranking of the three materials in terms of inherent toxicity, providing the following trend: GO > hBN ≈ MoS2 , with GO the most cytotoxic.

A comparative cytotoxic study against breast cancer cells with nanoparticles and rods shaped structures

The zinc oxide (ZnO) nanostructures are highly influential material and exhibit numerous properties. Numerous physicochemical applications for instance electronic, catalyst, solar cells, hydrogen fuels and energy evolution. Besides the large application in various directions very few reports are available for the cytotoxic evaluations and their compression with nano particles (NPs) and nanrorods (NRs) against the breast (MCF-7) cancer cells. The ZnO-NPs and NRs were produced through solution process in a short time span and were well characterized. The cells viability was tested with MTT and NRU assays. A series of different concentrations (2 μg/mL, 5 μg/mL, 10 μg/mL, 25 μg/ mL, 50 μg/mL, 100 μg/mL and 200 μg/mL) of NRs and NPs were employed against cancer cells for to evaluate the % activity of sustained and non-sustained cells. The morphology of treated and control cells were observed via microscopy respectively. Including this, the genetic studies were also scrutinized, cell-cycle analysis express the upsurge in the apoptotic peak after a 24-h. Quantitative PCR (qPCR) data revealed that the mRNA levels of apoptotic genes such as p53, bax, and caspase-3 were upregulated, whereas bcl-2, an anti-apoptotic gene, was downregulated; therefore, apoptosis was mediated through the p53, bax, caspase-3, and bcl-2 pathways.

Synthesis and comparative study of cytotoxicity and anticancer activity of Chalconoid-Co(II) metal complexes with 2-hydroxychalcones analogue containing naphthalene moiety

A series of six C1–C6 chalconoid based Co(II) complexes were prepared from bi-dentate 2-hydroxychalcones ligands L1-L6 containing naphthalene moiety. All synthesized metal-complexes have been evaluated to determine their cytotoxicity and anticancer activity against liver cancer cell line (Hep G2). Compared to standard 5-fluorouracil (IC50 ​= ​98.61 ​μg/mL), the metal complex C6 exhibits more potency with IC50 value 64.21 ​μg/mL against liver cancer cell line. While the remaining metal complexes such as C2, C4 and C5 are moderately active with IC50 value 314.93, 414.05 and 376.00 ​μg/mL respectively. The complexes C1 and C3 with IC50 value ​> ​1000 ​μg/mL are inadequate to display anticancer activity against Hep G2. Our perception towards the presence of organic group in the main structural moiety of complex C6 which associated with di-hydroxy (-OH) substituent at 3 and 4-position found more potent than complex C2, C4 and C5 which associated with halo (-Cl) substituent. The MTT assay revealed that the cytotoxicity and anticancer activity enhanced upon coordination of bio-ligand compared to free chalcone ligands. Therefore the present study may lead to the development of new class of anticancer drugs with structural modification.

A Comparative Study of Cytotoxicity of PPG and PEG Surface-Modified 2-D Ti3C2 MXene Flakes on Human Cancer Cells and Their Photothermal Response.

The MXenes are a novel family of 2-D materials with promising biomedical activity, however, their anticancer potential is still largely unexplored. In this study, a comparative cytotoxicity investigation of Ti3C2 MXenes with polypropylene glycol (PPG), and polyethylene glycol (PEG) surface-modified 2-D Ti3C2 MXene flakes has been conducted towards normal and cancerous human cell lines. The wet chemical etching method was used to synthesize MXene followed by a simple chemical mixing method for surface modification of Ti3C2 MXene with PPG and PEG molecules. SEM and XRD analyses were performed to examine surface morphology and elemental composition, respectively. FTIR and UV-vis spectroscopy were used to confirm surface modification and light absorption, respectively. The cell lines used to study the cytotoxicity of MXene and surface-modified MXenes in this study were normal (HaCaT and MCF-10A) and cancerous (MCF-7 and A375) cells. These cell lines were also used as controls (without exposure to study material and irradiation) to measure their baseline cell viability under the same lab environment. The surface-modified MXenes exhibited a sharp reduction in cell viability towards both normal (HaCaT and MCF-10A) and cancerous (MCF-7 and A375) cells but cytotoxicity was more pronounced towards cancerous cell lines. This may be due to the difference in cell metabolism and the occurrence of high pre-existing levels of reactive oxygen species (ROS) within cancerous cells. The highest toxicity towards both normal and cancerous cell lines was observed with PEGylated MXenes followed by PPGylated and bare MXenes. The normal cell’s viability was barely above 70% threshold with 250 mg/L PEGylated MXene concentration whereas PPGylated and bare MXene were less toxic towards normal cells, even at 500 mg/L concentration. Moreover, the toxicity was found to be directly related to the type of cell lines. In general, the HaCaT cell line exhibited the lowest toxicity while toxicity was highest in the case of the A375 cell line. The photothermal studies revealed high photo response for PEGylated MXene followed by PPGylated and bare MXenes. However, the PPGylated MXene’s lower cytotoxicity towards normal cells while comparable toxicity towards malignant cells as compared to PEGylated MXenes makes the former a relatively safe and effective anticancer agent.

Comparative Study of Antimicrobial Activity and Cytotoxicity of Saponin Extracted from Six Egyptian Sea-cucumber Species, Licorice, and Ginseng

Background: The study aimed to compare the antimicrobial activity and cytotoxicity of saponin extracted from six sea-cucumber species, licorice, and ginseng to determine the most potent one. Methods: Antimicrobial activity assessed by well diffusion and agar dilution methods. The inhibitory effects of the tested extracts on cell growth of Liver (HePG-2) and breast (MCF-7) cell lines assessed by MTT [3- (4, 5- dimethyl thiazol-2yl) - 2, 5- diphenyl tetrazolium bromide] assay. Results: The results revealed that licorice extract presented higher antibacterial activity against Gram-positive bacterial strains than sea-cucumber extracts; but has comparable results for Gramnegative (Salmonella tyhimurium, Klebsiella spp, and Acinetobacter baumanii). Holothuria atra body wall and Bohadschia tubules have the highest antifungal effect against Candida albicans, Candida krusei, Candida famata, Candida glabrata, and Candida tropicalis. Sea-cucumbers are more potent against fungal strains than licorice and ginseng extract. Licorice and ginseng presented higher cytotoxicity against HePG2 and MCF-7 cell lines than sea-cucumbers. Conclusion: This study promotes the use of licorice extract as a better antibacterial substance than sea-cucumber extracts; however, the use of sea-cucumber extracts as antifungal agents than herbal extracts. Also, we support the utilization of licorice and ginseng as a cytotoxic agent instead of seacucumbers to stop the fishing of animals and consequently save it from extinction.

Comparative Cytotoxicity Study of PM2.5 and TSP Collected from Urban Areas.

Ambient particulate matter 2.5 (PM2.5) and total suspended particles (TSPs) are common airborne pollutants that cause respiratory and cardiovascular diseases. We investigated the differences of cytotoxicity and mechanism between PM2.5 and TSP activity in human alveolar epithelial A549 cells. Atmospheric samples from the central district of Seoul were collected and their chemical compositions were analyzed by inductively-coupled plasma mass spectrometry and ion chromatography. PM2.5 and TSP contained high concentrations of heavy metals (Cu, Fe, Zn, and Pb). The most abundant ions in PM2.5 were SO42−, NH4+, and NO3−. A549 cells were exposed to PM2.5 and TSP (25–200 µg/mL) for 24 h. TSP was more cytotoxic than PM2.5 per unit mass. PM2.5 induced oxidative stress, as evidenced by increased levels of a glutamate-cysteine ligase modifier, whereas low-concentration TSP increased hemeoxygenase-1 levels. PM2.5 and TSP did not affect c-Jun N-terminal kinase expression. The levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in PM2.5- and TSP-treated cells decreased significantly in the cytosol and increased in the nucleus. Thus, Nrf2 may be a key transcription factor for detoxifying environmental airborne particles in A549 cells. TSP and PM2.5 could activate the protective Kelch-like ECH-associated protein 1/Nrf2 pathway in A549 cells.

Comparative Study of Cytotoxicity, DNA Damage and Oxidative Stress Induced by Heavy Metals Cd(II), Hg(II) and Cr(III) in Yeast.

Wide range of applications of heavy metals and improperly discarded their castoffs possess serious threats to environment and human health. In this study, cytotoxicity, DNA damage and oxidative stress induced by Cd(II), Hg(II) and Cr(III) were comparatively studied in yeast Saccharomyces cerevisiae. Cd(II), Hg(II), and Cr(III) all produced strong cytotoxicity resulting in growth inhibition and cell mortality to varying degrees (Hg(II) > Cd(II) > Cr(III)). Hg(II) produced more oxidative stress. Cr(III) caused more serious DNA damage in vitro. Cd(II) also caused both obvious DNA damage and oxidative stress at higher concentration, but not as efficiently as Cd(II) and Hg(II). A further null mutation sensitivity assay showed that the relative sensitivity of rad1∆ to the metals was Cr(III) > Cd(II) > Hg(II), and that of trx1∆ to the metals was Hg(II) > Cd(II) > Cr(III). These data provide a clear evidence that the Cr(III) can cause significant DNA damage and potential genotoxicity; Hg(II) can strongly inhibit SOD activity, produce lipid peroxidation and cause serious membrane injury, suggesting these heavy metals can cause different toxic effects in different ways.

Comparative cytotoxic study of silica materials functionalised with essential oil components in HepG2 cells

This work evaluated the cytotoxic effect of different EOCs-functionalised silica particle types. The in vitro toxicity of eugenol and vanillin-immobilised SAS, MCM-41 microparticles and MCM-41 nanoparticles was evaluated on HepG2 cells, and compared to free EOCs and pristine materials. The results revealed that free essential oil components and bare silica had a mild cytotoxic effect on HepG2 cells. However, the comparative study showed that free eugenol and vanillin had a milder cytotoxic effect than the equivalent concentrations of immobilised components on the different silica particles, while differences in cell viability between the bare and functionalised particles relied on the type of analysed material. The most cytotoxic materials were eugenol and vanillin-functionalised MCM-41 micro with IC50 values of 0.19 and 0.17 mg/mL, respectively, at 48 h exposure. Differences in cytotoxicity between functionalised particles may be attributed to the density of the functional components on their surface as a result of the functionalisation reaction performance for different materials. The study of the physico-chemical properties of particles demonstrated that cationic nature and increased hydrophobicity could be responsible for promoting cell-particle interactions for the eugenol and vanillin functionalised silica particles, enhancing their cytotoxic behaviour.