In vitro cytotoxicity assays: Comparison of LDH, neutral red, MTT and protein assay in hepatoma cell lines following exposure to cadmium chloride

Effects of rhinovirus species on viral replication and cytokine production

BACKGROUND

Epidemiologic studies provide evidence of differential virulence of rhinovirus species (RV). We recently reported that RV-A and RV-C induced more severe illnesses than RV-B, which suggests that the biology of RV-B might be different from RV-A or RV-C.

OBJECTIVE

To test the hypothesis that RV-B has lower replication and induces lesser cytokine responses than RV-A or RV-C.

METHODS

We cloned full-length cDNA of RV-A16, A36, B52, B72, C2, C15, and C41 from clinical samples and grew clinical isolates of RV-A7 and RV-B6 in cultured cells. Sinus epithelial cells were differentiated at the air-liquid interface. We tested for differences in viral replication in epithelial cells after infection with purified viruses (10(8) RNA copies) and measured virus load by quantitative RT-PCR. We measured lactate dehydrogenase (LDH) concentration as a marker of cellular cytotoxicity, and cytokine and/or chemokine secretion by multiplex ELISA.

RESULTS

At 24 hours after infection, the virus load of RV-B (RV-B52, RV-B72, or RV-B6) in adherent cells was lower than that of RV-A or RV-C. The growth kinetics of infection indicated that RV-B types replicate more slowly. Furthermore, RV-B released less LDH than RV-A or RV-C, and induced lower levels of cytokines and chemokines such as CXCL10, even after correction for viral replication. RV-B replicates to lower levels also in primary bronchial epithelial cells.

CONCLUSIONS

Our results indicate that RV-B types have lower and slower replication, and lower cellular cytotoxicity and cytokine and/or chemokine production compared with RV-A or RV-C. These characteristics may contribute to reduced severity of illnesses that has been observed with RV-B infections.

Purification and partial characterization of a chymotrypsin-like serine fibrinolytic enzyme from Bacillus amyloliquefaciens FCF-11 using corn husk as a novel substrate

A non-toxic, direct-acting fibrinolytic enzyme, FCF-11, from a newly isolated Bacillus amyloliquefaciens FCF-11 was purified, characterized and assayed both in vitro and in vivo for its thrombolytic potential. Corn husk was used as for the first time as the sole carbon/nitrogen source for enzyme production. The molecular weight of the purified enzyme was 18.2 kDa and purification increased its specific activity 443.5-fold with a recovery of 17 %. Maximal activity was attained at a temperature of 40 °C and pH of 8.0. Additionally the isoelectric point of this protein was 10 ± 0.2. Tosyl lysine chloromethyl ketone, phenylmethylsulphonyl fluoride, soybean trypsin inhibitor, and aprotinin highly repressed this activity. The presence of ethylenediaminetetraacetic acid, and two metalloprotease inhibitors, 2,2'-bipyridine and o-phenanthroline, didn't affect the enzymatic activity. Furthermore, it was found to exhibit a higher specificity for the chromogenic substrate S-2586 for chymotrypsin, indicating that the enzyme is a chymotrypsin-like serine protease. Its apparent K(m) and V(max) for the synthetic substrate N-Suc-Phe-pNA were 0.45 mM and 8.26 μmoles/mg/min, respectively. FCF-11 showed direct action upon blood clots in vitro and prolonged the blood clotting time to 4.1-fold, suggesting this enzyme be a beneficial thrombolytic agent especially, with regard with low molecular weight and non specificity to other plasma proteins. FCF-11 could not degrade collagen and was non-cytotoxic to HT29 cells or mammalian erythrocytes. Further, enzyme at a dose of 2 mg/kg was devoid of toxicity as well as hemorrhagic activity on BALB/c mouse model, supporting its suitability for the development of a better and safer thrombolytic drug.

Using a holistic approach to assess the impact of engineered nanomaterials inducing toxicity in aquatic systems

In this report, we critically reviewed selected intrinsic physicochemical properties of engineered nanomaterials (ENMs) and their role in the interaction of the ENMs with the immediate surroundings in representative aquatic environments. The behavior of ENMs with respect to dynamic microenvironments at the nano–bio–eco interface level, and the resulting impact on their toxicity, fate, and exposure potential are elaborated. Based on this literature review, we conclude that a holistic approach is urgently needed to fulfill our knowledge gap regarding the safety of discharged ENMs. This comparative approach affords the capability to recognize and understand the potential hazards of ENMs and their toxicity mechanisms, and ultimately to establish a quantitative and reliable system to predict such outcomes.

A novel peptide inhibitor of platelet aggregation from stiff silkworm, Bombyx batryticatus

A novel platelet aggregation inhibitory peptide, named BB octapeptide, was isolated from stiff silkworm (Bombyx batryticatus) by gel filtration, anion-exchange, and reverse-phase high performance liquid chromatography. The molecular mass of the peptide was determined to be 885 Da using electrospray ionization mass spectrometry, and the sequence was identified as Asp-Pro-Asp-Ala-Asp-IIe-Leu-Gln using the Edman degradation method. To test its biological activity, the peptide was chemically synthesized using Fmoc solid-phase synthesis method. BB octapeptide inhibited rabbit platelet aggregation that was induced by collagen and epinephrine, with the IC50 values of 91.14 μM and 104.50 μM, respectively. After intravenous administrated in mice (30 mg/kg, 4 days), BB octapeptide showed similar ex vivo efficacy of inhibiting platelet aggregation as aspirin (10 mg/kg). In addition, this peptide prevented paralysis and death in pulmonary thromboembolism model and significantly reduced ferric chloride-induced thrombus formation in rats. Moreover, it exhibited low cytotoxicity in a cellular model. In conclusion, this is the first report that a novel platelet aggregation inhibitory peptide was isolated from stiff silkworm (B. batryticatus). Due to the excellent efficacy in reducing platelet aggregation and low toxicity, it can be a valuable lead compound for new drug design and development.

Anticancer activity of structurally related ruthenium(II) cyclopentadienyl complexes

A set of structurally related Ru(η(5)-C5H5) complexes with bidentate N,N'-heteroaromatic ligands have been evaluated as prospective metallodrugs, with focus on exploring the uptake and cell death mechanisms and potential cellular targets. We have extended these studies to examine the potential of these complexes to target cancer cell metabolism, the energetic-related phenotype of cancer cells. The observations that these complexes can enter cells, probably facilitated by binding to plasma transferrin, and can be retained preferentially at the membranes prompted us to explore possible membrane targets involved in cancer cell metabolism. Most malignant tumors present the Warburg effect, which consists in increasing glycolytic rates with production of lactate, even in the presence of oxygen. The reliance of glycolytic cancer cells on trans-plasma-membrane electron transport (TPMET) systems for their continued survival raises the question of their appropriateness as a target for anticancer drug development strategies. Considering the interesting findings that some anticancer drugs in clinical use are cytotoxic even without entering cells and can inhibit TPMET activity, we investigated whether redox enzyme modulation could be a potential mechanism of action of antitumor ruthenium complexes. The results from this study indicated that ruthenium complexes can inhibit lactate production and TPMET activity in a way dependent on the cancer cell aggressiveness and the concentration of the complex. Combination approaches that target cell metabolism (glycolytic inhibitors) as well as proliferation are needed to successfully cure cancer. This study supports the potential use of some of these ruthenium complexes as adjuvants of glycolytic inhibitors in the treatment of aggressive cancers.

Combination use of ferulic acid, ligustrazine and tetrahydropalmatine inhibits the growth of ectopic endometrial tissue: a multi-target therapy for endometriosis rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ferulic acid (FA), ligustrazine (LZ) and tetrahydropalmatine (THP) are separately isolated from Chinese Angelica, Szechwan Lovage Rhizome and Rhizoma in the Jiawei-Foshou-San formula, a popular traditional Chinese medicine for irregular menses. It has been reported that the combination use of FA+LZ+THP has similar effect on endometriosis, but the underlying mechanisms are unclear. This study was to investigate the combination effects and mechanisms of FA+LZ+THP on endometriosis rats.

MATERIALS AND METHODS

Fifty endometriosis rats were intragastricly treated with FA+LZ+THP for 4 wk. The volume of ectopic endometrial tissue was measured to evaluate the effects. Then the changes in hypothalamic-pituitary-ovarian axis and ERE pathway were indicated by the levels of E2, GnRH, FSH and LH, and the expressions of ER, HSP90 and COX-2, respectively. In addition, peritoneal macrophages of each rat were cultured in vitro and treated with (FA+LZ+THP)-medicated serum for 24h. The proliferation and phagocytosis abilities, the levels of IL-1β and TNF-α, and the expression of IκBα were then measured for the changes of peritoneal macrophage activities.

RESULTS

Combination use of FA+LZ+THP diminished the volume of the ectopic endometrial tissues (P<0.05 or P<0.01). It also decreased the E2 level, suppressed the expression of GnRH, FSH and LH, and decreased the protein expression of ER, HSP90 and COX-2 (all P<0.05 or P<0.01). The phagocytosis ability of peritoneal macrophage was enhanced by (FA+LZ+THP)-medicated serum (P<0.05) with no change of proliferation (P>0.05). Moreover, IL-1β and TNF-α were downregulated (both P<0.05 or P<0.01) and IκBα was upregulated by the (FA+LZ+THP)-medicated serum (P<0.01).

CONCLUSIONS

The combination use of FA, LZ and THP could inhibit the growth of ectopic endometrial tissue in endometriosis rats. It might be related to the down-regulation of hypothalamic-pituitary-ovarian axis, the amelioration in ERE pathway and the improvement of peritoneal macrophage activities.

In vitro interaction of polyelectrolyte nanocapsules with model cells

The nanocapsules based on a liquid core with polyelectrolyte shells prepared by the technique of sequential adsorption of polyelectrolytes (LbL) were investigated to verify capsules bioacceptance. Using AOT (docusate sodium salt) as emulsifier, we obtained liquid cores, stabilized by the interfacial complex AOT/PLL (poly-l-lysine hydrobromide). These liquid cores were encapsulated by sequential adsorption of polyelectrolytes using biocompatible polyanion PGA (poly-l-glutamic acid sodium salt) and biocompatible polycation PLL. The average size of the formed capsules was 60-80 nm. The influence of a number of polyelectrolytes layer in the shell (thickness of polyelectrolytes shell), surface charge, and capsule doses on cell viability was studied in a cellular coculture assay. In order to improve nanocapsules biocompatibility, the PEG-ylated external layers were prepared using PGA-g-PEG (PGA grafted by PEG poly(ethylene glycol)). For the most toxic nanocapsules (with only one polycation layer) about 90% of cells could survive when the concentration of nanocapsules was below 0.2 × 10(6) per one cell. That suggests that they use as a delivery vehicles is quite safe for living cells. Analysis of internalization of AOT(PLL/PGA)4-g-PEG in HEK 293 cells indicates that tested nanocapsules can easily penetrate cells membrane.

Study of macrophage functions in murine J774 cells and human activated THP-1 cells exposed to oritavancin, a lipoglycopeptide with high cellular accumulation

Oritavancin, a lipoglycopeptide antibiotic in development, accumulates to high levels in the lysosomes of eukaryotic cells. We examined specific functions of macrophages (phagocytic capacity, lysosomal integrity, metabolic activity, and production of reactive oxygen species [ROS]) in correlation with the cellular accumulation of the drug, using J774 mouse macrophages and THP-1 human monocytes differentiated into macrophages using phorbol 12-myristate 13-acetate. Oritavancin did not affect Pseudomonas aeruginosa phagocytosis, lysosomal integrity, or metabolic activity in cells incubated for 3 h with extracellular concentrations ranging from 5 to 50 μg/ml. At extracellular concentrations of ≥25 μg/ml, oritavancin reduced latex bead phagocytosis by approximately 50% and doubled ROS production in J774 macrophages only. This may result from the fact that the cellular accumulation of oritavancin was 15 times higher in J774 cells than in activated THP-1 cells at 3 h. Human pharmacokinetic studies estimate that the concentration of oritavancin in alveolar macrophages could reach approximately 560 μg/ml after administration of a cumulative dose of 4 g, which is below the cellular concentration needed in the present study to impair latex bead phagocytosis (1,180 μg/ml) or to stimulate ROS production (15,000 μg/ml) by J774 cells. The data, therefore, suggest that, in spite of its substantial cellular accumulation, oritavancin is unlikely to markedly affect macrophage functions under the conditions of use investigated in current phase III trials (a single dose of 1,200 mg).

Synthesis of thermoresponsive polymers for drug delivery

A protocol for synthesizing thermosensitive copolymers of N-isopropylacrylamide (NIPAM) and N-vinylpyrrolidone (VP), cross-linked with N,N'-methylene-bis-acrylamide (MBA) has been described in this chapter. The copolymers have been formed at different concentrations of NIPAM and VP and at two different temperatures (70 °C and 30 °C). The lower critical solution temperature (LCST) of the samples has been measured, and the size of the particles formed with the highest concentration of NIPAM and lowest concentration of VP (MG1 and NG1) has been measured at three different temperatures of 25 °C, 35 °C, and 37 °C. Both MG1 and NG1 showed the lowest size at 37 °C. The MG1 and NG1 samples were further characterized using TEM and SEM. The MG1 particles were subsequently used for protein drug delivery, using BSA as a model. The release profile showed the best fit with the zero-order model. Finally, cytotoxicity studies of the synthesized MG1 and NG1 particles were carried out, using in vitro MTT assay, so as to determine the overall biocompatibility of the materials.

Preparation of Ginsenoside Rg3 and Protection against H2O2-Induced Oxidative Stress in Human Neuroblastoma SK-N-SH Cells

The aim of this study is to evaluate the protection of ginsenoside Rg3 against oxidative stress in human neuroblastoma SK-N-SH cells. 20(R)-ginsenoside Rg3 (20(R)-Rg3) and 20(S)-ginsenoside Rg3 (20(S)-Rg3) were prepared by the method of chemical degradation and column chromatography, and the structure of the two compounds was characterized by1H-NMR and13C-NMR spectroscopy. MTT assay and LDH leakage assay were used to determine the cell viability and the oxidative stress cellular model was established by means of H2O2(600 μM for 4 h). We also investigated the changes of intracellular MDA content, SOD activity, and ROS formation after the treatment of ginsenoside Rg3 for 20 h. The results indicated that both 20 (R)-Rg3 and 20 (S)-Rg3 had obvious protection against H2O2-induced oxidative stress in SK-N-SH cells. Moreover, 20(R)-Rg3 exhibited better antioxidant activity than 20(S)-Rg3in vitro. These findings are expected to provide some implication for further research and application of ginsenoside Rg3 in neuroprotection.

Mutations in subunit interface and B-cell epitopes improve antileukemic activities of Escherichia coli asparaginase-II: evaluation of immunogenicity in mice

L-Asparaginase-II from Escherichia coli (EcA) is a central component in the treatment of acute lymphoblastic leukemia (ALL). However, the therapeutic efficacy of EcA is limited due to immunogenicity and a short half-life in the patient. Here, we performed rational mutagenesis to obtain EcA variants with a potential to improve ALL treatment. Several variants, especially W66Y and Y176F, killed the ALL cells more efficiently than did wild-type EcA (WT-EcA), although nonleukemic peripheral blood monocytes were not affected. Several assays, including Western blotting, annexin-V/propidium iodide binding, comet, and micronuclei assays, showed that the reduction in viability of leukemic cells is due to the increase in caspase-3, cytochrome c release, poly(ADP-ribose) polymerase activation, down-regulation of anti-apoptotic protein Bcl-XL, an arrest of the cell cycle at the G0/G1 phase, and eventually apoptosis. Both W66Y and Y176F induced significantly more apoptosis in lymphocytes derived from ALL patients. In addition, Y176F and Y176S exhibited greatly decreased glutaminase activity, whereas K288S/Y176F, a variant mutated in one of the immunodominant epitopes, showed reduced antigenicity. Further in vivo immunogenicity studies in mice showed that K288S/Y176F was 10-fold less immunogenic as compared with WT-EcA. Moreover, sera obtained from WT-EcA immunized mice and ALL patients who were given asparaginase therapy for several weeks recognized the K288S/Y176F mutant significantly less than the WT-EcA. Further mechanistic studies revealed that W66Y, Y176F, and K288S/Y176F rapidly depleted asparagine and also down-regulated the transcription of asparagine synthetase as compared with WT-EcA. These highly desirable attributes of these variants could significantly advance asparaginase therapy of leukemia in the future.

Cytotoxic effects of Eryngium kotschyi and Eryngium maritimum on Hep2, HepG2, Vero and U138 MG cell lines

CONTEXT

Eryngium maritimum L. and the endemic Eryngium kotschyi Boiss. of the Apiaceae family are used for antiinflammatory, antivenom, antinociceptive and diuretic purposes in folk medicine in Turkey.

OBJECTIVE

This study investigated the cytotoxic effects of the plant extracts belonging to Eryngium L. genus on various cell lines.

MATERIALS AND METHODS

Cytotoxic activites of the lyophilized aqueous aereal and root parts of the plant extracts on human hepatocellular carcinoma (HepG2), human laryngeal epidermoid carcinoma (Hep2), human glioma (U138-MG) and African green monkey kidney epithelial (Vero) cell lines at 8.33-266.62 µg/ml concentrations were analyzed by lactate dehydrogenase (LDH) leakage and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) cell viability assays.

RESULTS

Inhibitory concentration 50 (IC50) values were found <100 µg/ml in most cases varying around 16.33-125.66 µg/ml. IC50 values for E. kostchyi and E. maritimum root parts on Hep2 cells (32.86 and 30.25 µg/ml, respectively), E. kotschyi aereal, E. maritimum aereal and root parts on HepG2 cells (31.75, 32.42 and 35.01 µg/ml, respectively) by MTT assay were found to be close to the US National Cancer Institute (NCI) recommendations (IC50 < 30 µg/ml) to define the antivity aganist cancer cells. The lowest IC50 values according to the LDH method were observed in Hep2 cells and the highest in U138-MG cells. Root parts were found to be more toxic than aereal parts for both plants in both methods in general.

DISCUSSION AND CONCLUSION

Both plant extracts exerted cytotoxic activity aganist Hep2 and HepG2 cells, with low IC50 values defining their promising anticancer property according to NCI; however, further analysis are needed to confirm their activity.

Biocompatibility of a novel cyanoacrylate based tissue adhesive: cytotoxicity and biochemical property evaluation

Cyanoacrylate (CA) is most widely used as a medical and commercial tissue adhesive because of easier wound closure, good cosmetic results and little discomfort. But, CA-based tissue adhesives have some limitations including the release of cytotoxic chemicals during biodegradation. In previous study, we made prepolymerized allyl 2-CA (PACA) based tissue adhesive, resulting in longer chain structure. In this study, we investigated a biocompatibility of PACA as alternative tissue adhesive for medical application, comparing with that of Dermabond® as commercial tissue adhesive. The biocompatibility of PACA was evaluated for short-term (24 hr) and long-term (3 and 7 days) using conventional cytotoxicity (WST, neutral red, LIVE/DEAD and TUNEL) assays, hematoxylin-eosin (H&E) and Masson trichrome (MT) staining. Besides we examined the biochemical changes in cells and DNA induced by PACA and Dermabond® utilizing Raman spectroscopy which could observe the denaturation and conformational changes in protein, as well as disintegration of the DNA/RNA by cell death. In particular, we analyzed Raman spectrum using the multivariate statistical methods including principal component analysis (PCA) and support vector machine (SVM). As a result, PACA and Dermabond® tissue adhesive treated cells and tissues showed no difference of the cell viability values, histological analysis and Raman spectral intensity. Also, the classification analysis by means of PCA-SVM classifier could not discriminate the difference between the PACA and Dermabond® treated cells and DNA. Therefore we suggest that novel PACA might be useful as potential tissue adhesive with effective biocompatibility.

Combination of fenretinide and selenite inhibits proliferation and induces apoptosis in ovarian cancer cells

The combination of fenretinide and selenite on ovarian cancer cells was investigated to assess its effects on proliferation and ability to induce apoptosis. Our results showed that fenretinide and selenite in combination significantly suppress the proliferation of ovarian cancer cells and induced apoptosis (including reactive oxygen species generation, and the loss of mitochondrial membrane potential) compared with either drug used alone. The caspase3/9-dependent pathway was triggered significantly in combination treatment, and moreover, the AMPK pathway also mediated the apoptosis induction in fenretinide and selenite combination. Fenretinide and selenite combination treatment was demonstrated to suppress tumor growth in vivo, this drug combination has been thus found to have an enhanced anti-tumor effect on ovarian cancers cells.

A simple and rapid detection of tissue adhesive-induced biochemical changes in cells and DNA using Raman spectroscopy

We demonstrate a cytotoxicity evaluation of tissue adhesive using Raman spectroscopy. This method allows for quantitative, label-free, non-invasive and rapid monitoring of the biochemical changes of cells following tissue adhesive treatment. Here, we show the biochemical property changes in mouse fibroblast L929 cells and cellular DNA following tissue adhesive (Dermabond) treatment using Raman spectroscopy. The Raman band intensities were significantly decreased when the cells were treated with Dermabond as compared to control cells. These results suggest denaturation and conformational changes in proteins and degradation of DNA related to cell death. To support these conclusions, conventional cytotoxicity assays such as WST, LIVE/DEAD, and TUNEL were carried out, and the results were in agreement with the Raman results. Thus, Raman spectroscopy analysis not only distinguishes between viable and damaged cells, but can also be used for identification and quantification of a cytotoxicity of tissue adhesive, which based on the cellular biochemical and structural changes at a molecular level. Therefore, we suggest that this method could be used for cytotoxic evaluation of tissue adhesives by rapid and sensitive detection of cellular changes.

Neurite outgrowth stimulatory effects of culinary-medicinal mushrooms and their toxicity assessment using differentiating Neuro-2a and embryonic fibroblast BALB/3T3

Background

Mushrooms are not only regarded as gourmet cuisine but also as therapeutic agent to promote cognition health. However, little toxicological information is available regarding their safety. Therefore, the aim of this study was to screen selected ethno-pharmacologically important mushrooms for stimulatory effects on neurite outgrowth and to test for any cytotoxicity.

Methods

The stimulatory effect of mushrooms on neurite outgrowth was assessed in differentiating mouse neuroblastoma (N2a) cells. Neurite length was measured using Image-Pro Insight processor system. Neuritogenesis activity was further validated by fluorescence immunocytochemical staining of neurofilaments. In vitro cytotoxicity was investigated by using mouse embryonic fibroblast (BALB/3T3) and N2a cells for any embryo- and neuro-toxic effects; respectively.

Results

Aqueous extracts of Ganoderma lucidum, Lignosus rhinocerotis, Pleurotus giganteus and Grifola frondosa; as well as an ethanol extract of Cordyceps militaris significantly (p < 0.05) promoted the neurite outgrowth in N2a cells by 38.4 ± 4.2%, 38.1 ± 2.6%, 33.4 ± 4.6%, 33.7 ± 1.5%, and 35.8 ± 3.4%; respectively. The IC₅₀ values obtained from tetrazolium (MTT), neutral red uptake (NRU) and lactate dehydrogenase (LDH) release assays showed no toxic effects following 24 h exposure of N2a and 3T3 cells to mushroom extracts.

Conclusion

Our results indicate that G. lucidum, L. rhinocerotis, P. giganteus, G. frondosa and C. militaris may be developed as safe and healthy dietary supplements for brain and cognitive health.

Recombinant lipoproteins reinforce cytotoxicity of doxorubicin to hepatocellular carcinoma

Cancer nanotherapeutics are changing the landscape of tumor treatment and used to circumvent limitations of conventional chemotherapy, such as non-specificity and low bioavailability. Reconstituted high density lipoproteins (rHDL) system is one of the most promising targeting delivery systems of chemotherapeutic drugs toward tumors. Here, we developed recombined high-density lipoprotein which can be functionalized to deliver doxorubicin intracellular with a higher efficiency. The cellular viability assay showed that the rHDL/Dox nanovectors had an enhanced efficiency in inhibiting the cell viability of hepatocellular carcinoma cell lines HepG2 and SMMC-7721. FACS and confocal microscopy was used to observe the doxorubicin delivery into cancer cells. Intracellular drug accumulation analysis confirmed that treatment of rHDL/Dox nanovectors resulted in higher intracellular doxorubicin concentration to the levels exceeding that of free drug. On the premise of efficient drug delivery, rHDL/Dox nanovectors have been preliminarily demonstrated effective inducing of cytotoxic effect and cell apoptosis to both of the cell lines in vitro. Tissue distribution experiment showed that rHDL/Dox nanovectors could also deliver doxorubicin to liver effectively. So, we proposed that this lipoprotein-based strategy holds promise for a safer and more efficient delivery of chemotherapeutic agents in the treatment of hepatocellular carcinoma.

PP2A ligand ITH12246 protects against memory impairment and focal cerebral ischemia in mice

ITH12246 (ethyl 5-amino-2-methyl-6,7,8,9-tetrahydrobenzo[b][1,8]naphthyridine-3-carboxylate) is a 1,8-naphthyridine described to feature an interesting neuroprotective profile in in vitro models of Alzheimer's disease. These effects were proposed to be due in part to a regulatory action on protein phosphatase 2A inhibition, as it prevented binding of its inhibitor okadaic acid. We decided to investigate the pharmacological properties of ITH12246, evaluating its ability to counteract the memory impairment evoked by scopolamine, a muscarinic antagonist described to promote memory loss, as well as to reduce the infarct volume in mice suffering phototrombosis. Prior to conducting these experiments, we confirmed its in vitro neuroprotective activity against both oxidative stress and Ca(2+) overload-derived excitotoxicity, using SH-SY5Y neuroblastoma cells and rat hippocampal slices. Using a predictive model of blood-brain barrier crossing, it seems that the passage of ITH12246 is not hindered. Its potential hepatotoxicity was observed only at very high concentrations, from 0.1 mM. ITH12246, at the concentration of 10 mg/kg i.p., was able to improve the memory index of mice treated with scopolamine, from 0.22 to 0.35, in a similar fashion to the well-known Alzheimer's disease drug galantamine 2.5 mg/kg. On the other hand, ITH12246, at the concentration of 2.5 mg/kg, reduced the phototrombosis-triggered infarct volume by 67%. In the same experimental conditions, 15 mg/kg melatonin, used as control standard, reduced the infarct volume by 30%. All of these findings allow us to consider ITH12246 as a new potential drug for the treatment of neurodegenerative diseases, which would act as a multifactorial neuroprotectant.

Nitric oxide donors: spermine/NO and diethylenetriamine/NO induce ovarian cancer cell death and affect STAT3 and AKT signaling proteins

The important features of cancer cells are uncontrolled growth and proliferation, as well as the ability to metastasis. These features depend mainly on the constant overexpression and activity of various cell signaling proteins, such as signal transducer and activator of transcription 3 (STAT3) and serine-threonine protein kinase AKT proteins. Nitric oxide (NO) has the potential of being anti-tumoral agent, however the exact character of anti-tumoral action of NO is still a matter of debate. In our research we used two NO donors, belonging to NONOates family, with different half-life times: spermine nitric oxide complex hydrate (SPER/NO t1/2=39min) and diethylenetriamine nitric oxide adduct (DETA/NO, t1/2=20h). We evaluated the cytotoxic effect of aforementioned NO donors on SK-OV-3 and OVCAR-3 ovarian cancer cell lines, as well as their effect on posttranslational modification of STAT3 and AKT proteins in these cells. We found that both NO donors present cytotoxic activity on the cancer cell lines, mainly through the induction of apoptosis. What is more, at the high concentration and longer exposure time they were also capable of inducing late apoptosis/necrosis. Both NO donors inhibited STAT3 and AKT3 proteins phosphorylation and down regulated their cytosolic levels, with DETA/NO being stronger inhibitor. We suggests, that NO donors have the potential to act as anti-tumoral agent through inhibiting cancer cell signaling and reducing their viability.

In vitro biological assessment of Berberis vulgaris and its active constituent, berberine: antioxidants, anti-acetylcholinesterase, anti-diabetic and anticancer effects

BACKGROUND

Berberis vulgaris is a well known plant with traditional herbal medical history. The aims of this study was to bioscreen and compare the in vitro biological activity (antioxidant, cholinergic, antidaibetic and the anticancer) of barberry crude extract and berberine active compound.

METHODS

The effect of B. vulgaris extract and berberine chloride on cellular thiobarbituric acid reactive species (TBARS) formation, diphenyle-α-picrylhydrazyl (DPPH) oxidation, cellular nitric oxide (NO) radical scavenging capability, superoxide dismutase (SOD), glutathione peroxidase (GPx), acetylcholinesterase (AChE) and α-gulcosidase activities were spectrophotometrically determined. On the other hand, the effect of extract and berberine as anticancer was estimated on three different cell lines which were MCF-7, HepG-2, and Caco-2 cells by using neutral red uptake assay which compared with control normal cells (PBMC).

RESULTS

Our results showed that barberry crude extract contains 0.6 mg berberine/mg crude extract. Barberry extract showed potent antioxidative capacity through decreasing TBARS, NO and the oxidation of DPPH that associated with GPx and SOD hyperactivation. Inhibitory effect of berberis crude extract on α-glucosidase was more potent than that of berberine chloride, while both had the same AChE inhibitory effect. Besides, different concentrations of both berberine chloride and barberry ethanolic extract showed to have no growth inhibitory effect on normal blood cells (PBMC). Otherwise, both berberine chloride and barberry ethanolic extract showed to have inhibitory effect on the growth of breast, liver and colon cancer cell lines (MCF7, HepG2 and CACO-2, respectively) at different incubation times starting from 24 hrs up to 72 hrs and the inhibitory effect increased with time in a dose dependent manner.

CONCLUSION

This work demonstrates the potential of the barberry crude extract and its active alkaloid, berberine, on suppressing lipid peroxidation, suggesting a promising use in the treatment of hepatic oxidative stress, Alzheimer and idiopathic male factor infertility. Beside, berberis vulgaris ethanolic extract is safe non-toxic extract as it was not inhibit the growth of PBMC that can induce cancer cell death that could return to its powerful antioxidant activity.

Electronic waste leachate-mediated DNA fragmentation and cell death by apoptosis in mouse fibroblast (NIH/3T3) cell line

This study investigated the apoptotic effect of electronic waste on fibroblast cell line. Cells were treated with different concentrations of the leachate for 24h. Cell viability was detected by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, nuclear morphology of cells was explored by acridine orange (AO)/ethidium bromide (EB) double staining, mitochondrial membrane potential was evaluated using JC-1 probe while cell cycle analysis was conducted using flow cytometry. The oxidative status was detected using DCFH-DA (dichlorofluorescin diacetate) probe and the relationship between cell death and ROS (reactive oxygen species) was investigated using N-acetylcysteine. Results showed an increased cell death as detected by MTT assay and AO/EB staining. Cell cycle analysis indicated an induction of sub/G1 events while JC-1 probe showed significant disruption of mitochondrial membrane potential. There was significant induction of ROS, while N-acetylcysteine protected the cells from DNA damage. These suggest apoptotic pathway as a possible mechanism of e-waste induced cyto-genotoxicity.

Chitosans for delivery of nucleic acids

Alternatives to efficient viral vectors in gene therapy are desired because of their poor safety profiles. Chitosan is a promising non-viral nucleotide delivery vector because of its biocompatibility, biodegradability, low immunogenicity and ease of manufacturing. Since the transfection efficiency of chitosan polyplexes is relatively low compared to viral counterparts, there is an impetus to gain a better understanding of the structure-performance relationship. Recent progress in preparation and characterisation has enabled coupling analysis of chitosans structural parameters that has led to increased TE by tailoring of chitosan's structure. In this review, we summarize the recent advances that have lead to a more rational design of chitosan polyplexes. We present an integrated review of all major areas of chitosan-based transfection, including preparation, chitosan and polyplexes physicochemical characterisation, in vitro and in vivo assessment. In each, we present the obstacles to efficient transfection and the strategies adopted over time to surmount these impediments.

Disinfection and toxicological assessments of pulsed UV and pulsed-plasma gas-discharge treated-water containing the waterborne protozoan enteroparasite Cryptosporidium parvum

We report for the first time on the comparative use of pulsed-plasma gas-discharge (PPGD) and pulsed UV light (PUV) for the novel destruction of the waterborne enteroparasite Cryptosporidium parvum. It also describes the first cyto-, geno- and ecotoxicological assays undertaken to assess the safety of water decontaminated using PPGD and PUV. During PPGD treatments, the application of high voltage pulses (16 kV, 10 pps) to gas-injected water (N2 or O2, flow rate 2.5L/min) resulted in the formation of a plasma that generated free radicals, ultraviolet light, acoustic shock waves and electric fields that killed ca. 4 log C. parvum oocysts in 32 min exposure. Findings showed that PPGD-treated water produced significant cytotoxic properties (as determined by MTT and neutral red assays), genotoxic properties (as determined by comet and Ames assays), and ecotoxic properties (as determined by Microtox™, Thamnotox™ and Daphnotox™ assays) that are representative of different trophic levels in aquatic environment (p<0.05). Depending in part on the type of injected gas used, PPGD-treated water became either alkaline (pH ≤ 8.58, using O2) or acidic (pH ≥ 3.21, using N2) and contained varying levels of reactive free radicals such as ozone (0.8 mg/L) and/or dissociated nitric and nitrous acid that contributed to the observed disinfection and toxicity. Chemical analysis of PPGD-treated water revealed increasing levels of electrode metals that were present at ≤ 30 times the tolerated respective values for EU drinking water. PUV-treated water did not exhibit any toxicity and was shown to be far superior to that of PPGD for killing C. parvum oocysts taking only 90 s of pulsing [UV dose of 6.29 μJ/cm(2)] to produce a 4-log reduction compared to a similar reduction level achieved after 32min PPGD treatment as determined by combined in vitro CaCo-2 cell culture-qPCR.

In vitro investigation of individual and combined cytotoxic effects of aflatoxin B1 and other selected mycotoxins on the cell line porcine kidney 15

In the present study, we evaluated the nephrotoxicity of individual mycotoxins and combinations of aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON), and fumonisin B1 (FB1) to livestock using porcine kidney 15 cells (PK-15) as a disease model via biochemical approaches. The toxicity of individual mycotoxins on cell viability and cell membrane damage was determined using the MTT and lactate dehydrogenase (LDH) assays, respectively. Individual cytotoxicity of mycotoxins in increasing order were FB1<ZEA<AFB1<DON. The MTT results of central composite design (CCD) showed synergetic effects after co-exposure of AFB1+ZEA or AFB1+DON; however, AFB1 and ZEA showed antagonistic effects in the ternary mixtures. AFB1 and DON significantly induced ROS production and apoptosis in a concentration-dependent manner, but ZEA (10-40μM) had no effect on cell apoptosis and only slightly induced ROS production. ZEA ameliorated the ROS production caused by 1μM AFB1; however, ZEA and DON displayed synergistic effects in combination with AFB1 at 5 and 10μM. The existence of 10μM ZEA attenuated AFB1-induced apoptosis. In conclusion, AFB1+ZEA or DON showed synergetic effects on cytotoxicity. Low levels of AFB1 were antagonistic to ZEA, but high doses of AFB1 displayed synergistic effects with ZEA or DON on oxidative damage. ZEA also ameliorated AFB1-induced apoptosis. Generally, the combined effects of mycotoxins acted in a concentration-dependent manner.

Cytotoxic and clastogenic activity of CdCl2 in human lymphocytes from different donors

The sensitivity of human lymphocytes from different donors to CdCl2 using a complex of methods for determination of cytotoxicity and genotoxicity was studied. As endpoints for cytotoxicity the mitotic index (MI) and apoptosis were evaluated. To indicate genotoxicity chromosome aberrations test (CA) was used. The results indicate an individual sensitivity of lymphocytes to CdCl2-induced damage, which is directly depending on the concentration (10(-6), 10(-5), 5×10(-5), 10(-4)mol/l) applied. The assessment of the toxic and genotoxic effect using various endpoints allows more complete risk estimation for organisms exposed to heavy metals. The results have direct practical significance for threat evaluation in humans.

Cytocompatibility and P-glycoprotein inhibition of block copolymers: structure-activity relationship

Amphiphilic polymeric micelles greatly improve the solubilization and sustained release of hydrophobic drugs and provide a protective environment for the cargo molecules in aqueous media, which favors lower drug administration doses, reduces adverse side effects, and increases blood circulation times and passive targeting to specific cells. These capabilities depend, among other variables, on the structure and composition of the polymer chains. Composition and, in particular, block length have been shown to play an important role in the modification of cellular responses such as drug internalization processes or transduction pathways when polymeric unimer/micelles are in close contact with cells. Here we present a detailed study about the role copolymer structure and composition play on cell viability and cellular response of several cell lines. To do that, more than 30 structurally related copolymers with diblock and triblock architectures containing different hydrophobic blocks and poly(ethylene oxide) as the common hydrophilic unit have been analyzed regarding cytocompatibility and potential as "active" cell response modifiers by testing their influence on the P-gp pump efflux mechanism responsible of multidrug resistance in cancerous cells. An empirical threshold for cell viability could be established at a copolymer EO/POeffective value above ca. 1.5 for copolymers with triblock structure, whereas no empirical rule could be observed for diblocks. Moreover, some of the tested copolymers (e.g., BO12EO227BO12 and EO57PO46EO57 that notably increased and C16EO455C16 that decreased the P-gp ATPase activity) were observed to act as efficient inhibitors of the P-gp efflux pump promoting an enhanced doxorubicin (DOXO) accumulation inside multidrug resistant (MDR) NCI-ADR-RES cells.

In vitro study of the cytotoxicity and antiproliferative effects of surfactants produced by Sphingobacterium detergens

The application of biosurfactants in the biomedical field is growing due to their antimicrobial activity, low cytotoxicity and ability to induce apoptosis in cancer cells. In the light of this therapeutic potential, as well as possible applications in cosmetics or as drug vehicles in pharmaceutical products, a new biosurfactant produced by Sphingobacterium detergens was investigated for its haemolytic activity and cytotoxic and antiproliferative effects in different cell lines. Fraction A showed 100% haemolysis in rabbit erythrocytes, but in Fraction B the rate was only 83%. When comparing cytotoxicity values (IC50) of the two fractions in model fibroblast and keratinocyte cell cultures, Fraction B was less cytotoxic, showing lower values than the reference compound SDS, indicating low skin irritability. Finally, in non-differentiated intestinal Caco-2 cultures, Fractions A and B reduced cell proliferation and induced apoptosis by 44% and 75%, respectively. According to these results, biosurfactants produced by S. detergens have potential application in cosmetic and pharmaceutical formulations.

Cytotoxic, genotoxic/antigenotoxic and mutagenic/antimutagenic effects of the venom of the wasp Polybia paulista

Hymenoptera venoms are constituted by a complex mixture of chemically or pharmacologically bioactive agents, such as phospholipases, hyaluronidases and mastoparans. Venoms can also contain substances that are able to inhibit and/or diminish the genotoxic or mutagenic action of other compounds that are capable of promoting damages in the genetic material. Thus, the present study aimed to assess the effect of the venom of Polybia paulista, a neotropical wasp, by assays with HepG2 cells maintained in culture. The cytotoxic potential of the wasp venom, assessed by the methyl thiazolyl tetrazolium assay (MTT assay), was tested for the concentrations of 10 μg/mL, 5 μg/mL and 1 μg/mL. As these concentrations were not cytotoxic, they were used to evaluate the genotoxic (comet assay) and mutagenic potential (micronucleus test) of the venom. In this study, it was verified that these concentrations induced damages in the DNA of the exposed cells, and it was necessary to test lower concentrations until it was found those that were not considered genotoxic and mutagenic. The concentrations of 1 ng/mL, 100 pg/mL and 10 pg/mL, which did not induce genotoxicity and mutagenicity, were used in four different treatments (post-treatment, pre-treatment, simultaneous treatment with and without incubation), in order to evaluate if these concentrations were able to inhibit or decrease the genotoxic and mutagenic action of methyl methanesulfonate (MMS). None of the concentrations was able to inhibit and/or decrease the MMS activity. The genotoxic and mutagenic activity of the venom of P. paulista could be caused by the action of phospholipase, mastoparan and hyaluronidase, which are able to disrupt the cell membrane and thereby interact with the genetic material of the cells or even facilitate the entrance of other compounds of the venom that can act on the DNA. Another possible explanation for the genotoxicity and mutagenicity of the venom can be the presence of substances able to trigger inflammatory process and, consequently, generate oxygen reactive species that can interact with the DNA of the exposed cells.

Biodistribution of sub-10 nm PEG-modified radioactive/upconversion nanoparticles

The biodistribution of lanthanide-based upconversion nanophosphors (UCNPs) has attracted increasing attention, and all of the reported UCNPs display metabolism in the liver and spleen mainly. Herein, ∼8 nm poly(ethylene glycol) (PEG)-coated NaYF4 nanoparticles codoped with Yb(3+), Er(3+), and (or) radioactive (153)Sm(3+) ions were synthesized, through a hydrothermal synthetic system assisted by binary cooperative ligands with oleic acid and PEG dicarboxylic acids. The as-prepared PEG-coating NaYF4:Yb,Er and NaYF4:Yb,Er,(153)Sm are denoted as PEG-UCNPs and PEG-UCNPs((153)Sm), respectively. PEG-UCNPs were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD) analysis, and Fourier-transform infrared (FTIR) spectroscopy. The PEG-UCNPs showed excellent water solubility with a hydrodynamic diameter of ∼10 nm and displayed upconversion luminescence (UCL) under continuous-wave excitation at 980 nm. At the same time, the (153)Sm-doped nanoparticles PEG-UCNPs((153)Sm) displayed radioactivity, and time-dependent biodistribution of PEG-UCNPs((153)Sm) was investigated, through single-photon emission computed tomography (SPECT) imaging and γ-counter analysis. Interestingly, PEG-UCNPs((153)Sm) had a long blood retention time and were partly eliminated through urinary pathways in vivo. Therefore, the concept of fabricating PEG-coated, small nanosize (sub-10 nm) nanoparticles with radioactive property is a useful strategy for providing a potential method to monitor lanthanide nanoparticles renal clearable.

Evaluation of triazole-chelated lanthanides as chemically stabile bioimaging agents

Europium (Eu), dysprosium (Dy), samarium (Sm), and terbium (Tb) complexes were prepared using the neutral tridentate chelator 2,6-bis(1-benzyl-1,2,3-triazol-4-yl)pyridine and one equivalent of each lanthanide salt. The physicochemical, aerodynamic, and in vitro cellular properties of each lanthanide metal complex were studied to determine their viability as cell surface fluorescent probes. Each compound was characterized by electrospray ionization mass spectroscopy (ESI-MS), ultraperformance liquid chromatography (UPLC), differential scanning calorimetry (DSC), and thermogravimetic analysis (TGA). Upon excitation at 320 nm each complex displayed characteristic lanthanide-based fluorescence emission in the visible wavelength range with stokes shifts greater than 200 nm. Each complex was found to be chemically stable when exposed to pH range of 1-11 for 72 h and resistant to photobleaching. To simulate pulmonary administration of these fluorophores, the aerodynamic properties of the Eu and Tb complexes were determined using a next generation impactor (NGI). This measurement confirmed that the complexes retain their fluorescence emission properties after nebulization. Cellular cytotoxicity was determined on A-549 lung cancer cell line using methylthiazol tetrazolium (MTT) cytotoxicity assay at 24, 48, and 72 h postexposure to the complexes. The complexes showed a dose and time-dependent effect on the percent viability of the cells.

Development of biodegradable methylprednisolone microparticles for treatment of articular pathology using a spray-drying technique

In this work, microparticles were prepared by spray-drying using albumin, chondroitin sulfate, and hyaluronic acid as excipients to create a controlled-release methylprednisolone system for use in inflammatory disorders such as arthritis. Scanning electron microscopy demonstrated that these microparticles were almost spherical, with development of surface wrinkling as the methylprednisolone load in the formulation was increased. The methylprednisolone load also had a direct influence on the mean diameter and zeta potential of the microparticles. Interactions between formulation excipients and the active drug were evaluated by x-ray diffraction, differential scanning calorimetry, and thermal gravimetric analysis, showing limited amounts of methylprednisolone in a crystalline state in the loaded microparticles. The encapsulation efficiency of methylprednisolone was approximately 89% in all formulations. The rate of methylprednisolone release from the microparticles depended on the initial drug load in the formulation. In vitro cytotoxic evaluation using THP-1 cells showed that none of the formulations prepared triggered an inflammatory response on release of interleukin-1β, nor did they affect cellular viability, except for the 9.1% methylprednisolone formulation, which was the maximum test concentration used. The microparticles developed in this study have characteristics amenable to a therapeutic role in inflammatory pathology, such as arthritis.

1'-acetoxychavicol acetate inhibits adipogenesis in 3T3-L1 adipocytes and in high fat-fed rats

Alpinia galanga and Languas galanga, which are plants belonging to the ginger family, are frequently used for cooking, especially in Thai and Indonesian cuisine. The compound 1'-acetoxychavicol acetate (ACA), which is naturally obtained from the rhizomes and seeds of these gingers, has antioxidant and anti-inflammatory properties. We investigated the anti-obesity effects of ACA in 3T3-L1 adipocytes and in high fat diet (HFD)-induced rat models of obesity. ACA caused a significant decrease in the activity of GPDH in 3T3-L1 adipocytes without eliciting cell cytotoxicity, and it inhibited cellular lipid accumulation through the down-regulation of transcription factors such as PPARγ and C/EBPα. ACA also induced a dose-dependent phosphorylation of AMP-activated protein kinase (AMPK). In the animal model, rats fed an HFD containing 0.05% ACA gained less weight than rats fed an HFD alone. The visceral fat mass in rats fed an HFD containing 0.05% ACA tended to be lower than that in rats fed an HFD alone. Furthermore, a histological examination of livers from rats fed an HFD showed steatohepatitis. However, rats fed an HFD containing 0.05% ACA showed no histopathological changes in the liver tissue. Our results show that ACA exerts anti-obesity activities both in vitro and in vivo and suggests that ACA may have a novel preventive activity against obesity and possibly other metabolic diseases.

In vitro effect of N-acetylcysteine on hepatocyte injury caused by dichlorodiphenyltrichloroethane and its metabolites

The organochlorine pesticide, dichlorodiphenyltrichloroethane (DDT), is still used to combat the spread of malaria in several developing countries despite its accumulation and known hepatotoxic effects that have been demonstrated both in vitro and in vivo. N-Acetylcysteine (NAC) is a recognized hepatoprotective agent that has been reported to reduce hepatotoxicity initiated by many different compounds. The aim of this study was to determine whether NAC could counter in vitro hepatocyte injury induced by DDT or its two major metabolites, dichlorodiphenyldichloroethylene and dichlorodiphenyldichloroethane. HepG2 cell cultures were used to assess the following parameters of toxicity: cellular viability, intracellular levels of reactive oxygen species (ROS), mitochondrial membrane potential and initiation of apoptosis. None of the three test compounds induced ROS generation, yet exposure to any of the three compounds produced mitochondrial hyperpolarization, which was countered by NAC pretreatment. All three test compounds also induced apoptotic cell death, which was inhibited by NAC. Despite NAC counteracting some adverse intracellular changes due to organochlorine exposure, it appeared to aggravate the cytotoxic effects of the organochlorine compounds at low test concentrations. As the same outcome may also occur in vivo, results from the present study raise concern about the use of NAC as treatment for DDT-induced hepatotoxicity.

Toxic effect of silica nanoparticles on endothelial cells through DNA damage response via Chk1-dependent G2/M checkpoint

Silica nanoparticles have become promising carriers for drug delivery or gene therapy. Endothelial cells could be directly exposed to silica nanoparticles by intravenous administration. However, the underlying toxic effect mechanisms of silica nanoparticles on endothelial cells are still poorly understood. In order to clarify the cytotoxicity of endothelial cells induced by silica nanoparticles and its mechanisms, cellular morphology, cell viability and lactate dehydrogenase (LDH) release were observed in human umbilical vein endothelial cells (HUVECs) as assessing cytotoxicity, resulted in a dose- and time- dependent manner. Silica nanoparticles-induced reactive oxygen species (ROS) generation caused oxidative damage followed by the production of malondialdehyde (MDA) as well as the inhibition of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Both necrosis and apoptosis were increased significantly after 24 h exposure. The mitochondrial membrane potential (MMP) decreased obviously in a dose-dependent manner. The degree of DNA damage including the percentage of tail DNA, tail length and Olive tail moment (OTM) were markedly aggravated. Silica nanoparticles also induced G2/M arrest through the upregulation of Chk1 and the downregulation of Cdc25C, cyclin B1/Cdc2. In summary, our data indicated that the toxic effect mechanisms of silica nanoparticles on endothelial cells was through DNA damage response (DDR) via Chk1-dependent G2/M checkpoint signaling pathway, suggesting that exposure to silica nanoparticles could be a potential hazards for the development of cardiovascular diseases.

A novel method for the preparation of a neurotoxic complex

Neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) can be attributed to the specific degeneration of neuronal cells in the brain. However, the natures and action modes of toxic species remain largely unknown. Here, we present a simple and fast method for the preparation of neurotoxic complex with α-synuclein, which is implicated in PD.

Comparison of five different in vitro assays for assessment of sodium metavanadate cytotoxicity in Chinese hamster ovary cells (CHO-K1 line)

This investigation was undertaken to compare five different in vitro cytotoxicity assays for their power in revealing vanadium-mediated toxicity in Chinese hamster ovary (CHO)-K1 cells. The cells were exposed to sodium metavanadate (NaVO3) in the range of 10–1000 µM for 24 h and thereafter the cytotoxic effects of NaVO3 were measured by colorimetric in vitro assays: the neutral red (NR) test, the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt (XTT) assay, the resazurin assay, the sulforhodamine B (SR-B) assay, and by microscopic assessment of cell viability using the trypan blue (TB) staining method. Among the assays used, the NR test was the most sensitive, since it revealed metavanadate cytotoxicity at the lowest NaVO3 dose (=50 µM). Also, NaVO3 cytotoxicity expressed as inhibitory concentration (IC) showed the lowest values for the NR test. Three other tests XTT, resazurin, and SR-B assays showed intermediate sensitivity revealing the cytotoxicity of NaVO3 at 100 µM. The corresponding IC10 and IC50 values calculated for the XTT, resazurin, and SR-B tests were similar. The TB staining method was the least sensitive, since it recorded metavanadate cytotoxicity at the highest NaVO3 concentration tested (=600 µM). Based on the cytotoxicity end points measured with the above assays, it can be concluded that lysosomal/Golgi apparatus damage (measured by NR assay) may be the primary effect of NaVO3 on CHO-K1 cells. The disintegration of mitochondria (assessed with the XTT and resazurin assays) probably follows lysosomal impairment. Plasma membrane permeability (staining with TB) occurs at a late stage of NaVO3-induced cytotoxicity on CHO-K1 cells. The results obtained in this research work show that the NR test can be recommended as a very sensitive assay for the assessment of NaVO3 cytotoxicity in the CHO-K1 cell culture model. Considering the convenience of assay performance along with adequate sensitivity, the XTT and resazurin assays can also be advocated for NaVO3 cytotoxicity assessment.

Toxicological profiles of selected synthetic cannabinoids showing high binding affinities to the cannabinoid receptor subtype CB₁

Products containing synthetic cannabinoids are consumed as a surrogate for marihuana due to their non-detectability with commonly used drug tests and their strong cannabimimetic effects. Because data concerning their toxicological properties are scarce, the cytotoxic, genotoxic, immunomodulatory, and hormonal activities of four naphthoylindole compounds (JWH-018, JWH-073, JWH-122 and JWH-210) and of one benzoylindole (AM-694) were studied in human cell lines and primary cells; tetrahydrocannabinol was included as the classical non-endogenous cannabinoid receptor ligand. All compounds induced damage to the cell membranes of buccal (TR146) and breast (MCF-7) derived cells at concentrations of ≥75-100 μM. No cytotoxic responses were seen in other assays which reflect mitochondrial damage, protein synthesis, and lysosomal activities. JWH-073 and JWH-122 induced DNA migration in buccal and liver cells (HepG2) in single cell gel electrophoresis assays, while JWH-210 was only in the latter cell line active. No estrogenic activities were detected in bone marrow cells (U2-OS), but all compounds caused anti-estrogenic effects at levels between 2.1 and 23.0 μM. Furthermore, no impact on cytokine release (i.e., on IL-10, IL-6, IL-12/23p40 and TNFα levels) was seen in LPS-stimulated human PBMCs, except with JWH-210 and JWH-122 which caused a decrease of TNFα and IL-12/23p40. All toxic effects were observed with concentrations higher than those expected in body fluids of users. Since genotoxic effects are in general linear over a wide concentration range and the exposure levels may be higher in epithelial cells than [corrected] in serum, further experimental work is required to find out if DNA damage takes place in drug users.

A Phenylbutenoid Dimer, cis-3-(3',4'-Dimethoxyphenyl)-4-[(E)-3''',4'''-Dimethoxystyryl] Cyclohex-1-ene, Exhibits Apoptogenic Properties in T-Acute Lymphoblastic Leukemia Cells via Induction of p53-Independent Mitochondrial Signalling Pathway

The current study was designed to evaluate the in vitro cytotoxicity effect of a phenylbutenoid dimer, cis-3-(3',4'-dimethoxyphenyl)-4-[(E)-3 (‴) ,4 (‴) -dimethoxystyryl]cyclohex-1-ene (ZC-B11) isolated from the rhizome of Zingiber cassumunar on various cancer cell line, and normal human blood mononuclear cells, and to further investigate the involvement of apoptosis-related proteins that leads, to the probable pathway in which apoptosis is triggered. Cytotoxicity test using MTT assay showed selective inhibition of ZC-B11 towards T-acute lymphoblastic leukemia cells, CEMss, with an IC50 value of 7.11 ± 0.240  μ g/mL, which did not reveal cytotoxic effects towards normal human blood mononuclear cells (IC50 > 50  μ g/mL). Morphology assessments demonstrated distinctive morphological changes corresponding to a typical apoptosis. ZC-B11 also arrested cell cycle progression at S phase and causes DNA fragmentation in CEMss cells. Decline of mitochondrial membrane potential was also determined qualitatively. In the apoptosis-related protein determination, ZC-B11 was found to significantly upregulate Bax, caspase 3/7, caspase 9, cytochrome c, and SMAC and downregulate Bcl-2, HSP70, and XIAP, but did not affect caspase 8, p53, and BID. These results demonstrated for the first time the apoptogenic property of ZC-B11 on CEMss cell line, leading to the programmed cell death via intrinsic mitochondrial pathway of apoptosis induction.