Time- and Concentration-Dependent Adverse Effects of Paclitaxel on Non-Neuronal Cells in Rat Primary Dorsal Root Ganglia

Paclitaxel is a chemotherapeutic agent used to treat a wide range of malignant tumors. Although it has anti-tumoral properties, paclitaxel also shows significant adverse effects on the peripheral nervous system, causing peripheral neuropathy. Paclitaxel has previously been shown to exert direct neurotoxic effects on primary DRG neurons. However, little is known about paclitaxel's effects on non-neuronal DRG cells. They provide mechanical and metabolic support and influence neuronal signaling. In the present study, paclitaxel effects on primary DRG non-neuronal cells were analyzed and their concentration or/and time dependence investigated. DRGs of Wister rats (6-8 weeks old) were isolated, and non-neuronal cell populations were separated by the density gradient centrifugation method. Different concentrations of Paclitaxel (0.01 µM-10 µM) were tested on cell viability by MTT assay, cell death by lactate dehydrogenase (LDH) assay, and propidium iodide (PI) assay, as well as cell proliferation by Bromodeoxyuridine (BrdU) assay at 24 h, 48 h, and 72 h post-treatment. Furthermore, phenotypic effects have been investigated by using immunofluorescence techniques. Paclitaxel exhibited several toxicological effects on non-neuronal cells, including a reduction in cell viability, an increase in cell death, and an inhibition of cell proliferation. These effects were concentration- and time-dependent. Cellular and nuclear changes such as shrinkage, swelling of cell bodies, nuclear condensation, chromatin fragmentation, retraction, and a loss in processes were observed. Paclitaxel showed adverse effects on primary DRG non-neuronal cells, which might have adverse functional consequences on sensory neurons of the DRG, asking for consideration in the management of peripheral neuropathy.

Assessment of HMGB1 Release During Experimentally Induced Pyroptosis

Inflammasomes are multiprotein complexes that can be activated by a wide array of infectious and inflammatory agents. Inflammasome activation culminates in the maturation and secretion of pro-inflammatory cytokines, as well as lytic cell death, known as pyroptosis. During pyroptosis, the entire contents of a cell are released into the extracellular space, propagating the local innate immune response. One component of particular interest is the alarmin high mobility group box-1 (HMGB1). Extracellular HMGB1 is a potent inflammatory stimulus, acting upon multiple receptors to drive inflammation. In this series of protocols, we will outline how to trigger and assess pyroptosis in primary macrophages, with a focus on the assessment of HMGB1 release.

Nanodesigned coatings obtained by plasma electrolytic oxidation of titanium implant and their cytotoxicity

The titanium implant was treated with plasma electrolytic oxidation and subsequent ionic exchange and thermal treatment in order to obtain bioactive layer consisting of titanium oxide, calcium and sodium titanates and hydroxyapatite, as confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) revealed that the given method, besides corresponding phase composition, enables suitable nanotopology for cell attachment and proliferation. Cytotoxicity investigations by MTT, LDH and propidium iodide assays and light microscopy showed that these coatings were not toxic to L929 cells.

Neuroprotective effects of Bhilawanol and Anacardic acid during glutamate-induced neurotoxicity

Bhilawanol (Bh) and anacardic acid (AA) are two lipid-soluble compounds mostly found in the nut of Semecarpus anacardium (SA). This herb has many medicinal properties including enhancing learning and memory, yet its active compounds have not been studied for neuroprotective effects. We investigated the neuroprotective effects of Bh and AA against glutamate induced cell death in the adrenal pheochromocytoma cell line of rats (PC12 cells). Cell viability, toxicity and calcium influx were determined by MTT assay, LDH release assay and Fluo-3 imaging while apoptosis was assayed by caspase-3 and Bcl-2 gene expression. Our results showed that Bh and AA treatments significantly increased cell viability, reduced cell toxicity and calcium influx in PC12 cells in addition to suppressing the reactive oxygen species. Furthermore, AA treatment decreased caspase-3 expression level whereas both Bh and AA enhanced the expression of anti-apoptotic gene Bcl-2 in PC12 cells. Both compounds potently inhibited acetylcholinesterase enzyme (AChE) in a dose and time dependent manner. These findings suggest that the traditional use of SA may be explained on the basis of both Bh and AA showing neuroprotective potential due to their effects on enhancing cell viability, reducing cell toxicity most probably by reducing excessive calcium influx and suppression of ROS as well as by decreasing the expression of proapoptotic caspase 3 gene and increasing the expression of antiapoptotic gene Bcl2. Traditional use in enhancing learning and memory was justified in part by inhibition of AChE.

Cratoxylum sumatranum stem bark exhibited antimalarial activity by Lactate Dehydrogenase (LDH) assay

OBJECTIVES

The antimalarial drug resistance is an obstacle in the effort to overcome malaria. The new alternative antimalarial drug became in great attention of urgent need. Current antimalarial drugs were derived from plants. Therefore, the plant is considering a potential source of new drugs. Cratoxylum sumatranum belongs to the Hypericaceae family contain xanthones and phenolic compounds, which was reported for their antimalarial activities. This study aims to determine the antimalarial activities of C. sumatranum extracts and fractions.

METHODS

Cratoxylum  sumatranum stem bark (BP14-SB) collected from Balikpapan Botanical Garden in East Kalimantan, Indonesia, was extracted gradually with n-hexane, dichloromethane, and methanol by ultrasonic-assisted extraction method. All extracts were tested against Plasmodium falciparum 3D7 by lactate dehydrogenase (LDH) assay and followed by IC₅₀ determination. The most active extract was further separated and tested for their antimalarial activities.

RESULTS

The results showed that dichloromethane stem bark extract (BP14-SB-D) had the strongest inhibition of parasite growth with the IC₅₀ value of 0.44 ± 0.05 μg/mL and moderately toxic with the CC₅₀ value of 29.09 ± 0.05 μg/mL. Further fractionation of BP14-SB-D by open column chromatography using silica gel and gradient hexane-ethyl acetate obtained 12 fractions. LDH assay for these 12 fractions of BP14-SB-D showed that Fraction-6 (IC₅₀ value of 0.19 ± 0.03 μg/mL) was performed the strongest inhibition of parasite growth, compared to other fractions. TLC identification showed that BP14-SB-D contains xanthone.

CONCLUSIONS

The dichloromethane extract of C. sumatranum stem bark (BP14-SB-D) and Fraction-6 from this extract exhibited antimalarial activity and the potential to be developed an antimalarial substance.

Pharmacological Potentiality of Bioactive Flavonoid against Ketamine Induced Cell Death of PC 12 Cell Lines: An In Vitro Study

During the past few years, there has been exponential growth in the field of ethnopharmacology in the treatment of different human ailments, including neurological disorders. In our previous study, we isolated, characterized, and reported a novel bioactive compound with therapeutic efficacy in vivo, which was used in the current study. This study was designed to investigate the pharmacological effect and therapeutic mechanism of the natural plant compound 3-(3,4-dimethoxy phenyl)-1-(4-methoxy phenyl)prop-2-en-1-one against ketamine-induced toxicity in PC 12 cell lines. Cell death was induced in PC 12 cell lines by incubating with ketamine, and the protection offered by the compound at different concentrations was studied during pretreatment. The therapeutic efficacy was screened through MTT assay, LDH assay, DCF-DA assay, clonogenic assay, RT-PCR, and densitometric analysis. The bioactive compound caused a significant elevation in cell viability up to approximately 80%, down-regulation of cell damage, reduction in free radical damage caused by intracellular reactive oxygen species, and up-regulation of cell survival ability, which was dysregulated during ketamine induction. In addition, RT-PCR analysis of DOPA-related genes suggests that the compound exerted significant inhibition in the expression of these genes, which were overexpressed during ketamine induction. The current findings provide new insight into the neuroprotective mediation of bioactive factors as a prospective therapy for neurological disorders.

Comparison of cytotoxicity of black phosphorus nanosheets in different types of fibroblasts

BACKGROUND

Two-dimensional black phosphorus nanosheets (BPNSs) have recently emerged as a successive novel nanomaterial owing to their uniqueness in optical and electrical properties. Although BPNSs have found a wide range of biomedical applications, their biosafety is still a major concern to be addressed.

METHODS

In this study, we have prepared layered BPNSs using liquid exfoliation procedure, and evaluated their physicochemical properties using Fourier Transform-infrared (FTIR) spectroscopy, Raman spectroscopy, atomic force microscopy, and Zetasizer analyses. We have investigated potential cytotoxicity of BPNSs against three different types of fibroblast cells, i.e. mouse embryonic fibroblast (NIH3T3), primary cultured normal human dermal fibroblast (nHDF), and fibrosarcoma (HT1080). Cell counting kit-8 (CCK-8) assay was carried out to assess cellular metabolic activity in cells whereas lactate dehydrogenase (LDH) activity assay was helpful to study plasma membrane integrity.

RESULTS

Our salient research findings showed that BPNSs were polydispersed in solution due to aggregation. Toxic response of BPNSs against fibroblast cells was in the order, HT1080>nHDF>NIH3T3. The nanosheets reduced the number of cancerous cells with significant difference to normal cells.

CONCLUSIONS

We suggest that BPNSs can be considered for cancer treatment as they destroy cancerous cells effectively. However, a comprehensive study is required to elucidate other biological effects of BPNSs.

Carbon Nanotube Reinforced Hydroxyapatite Nanocomposites As Bone Implants: Nanostructure, Mechanical Strength And Biocompatibility

PURPOSE

Hydroxyapatite (HA) is a biologically active ceramic which promotes bone growth, but it suffers from relatively weak mechanical properties. Multi-walled carbon nanotubes (MWCNTs) have high tensile strength and a degree of stiffness that can be used to strengthen HA; potentially improving the clinical utility of the bone implant.

METHODS

HA was precipitated by the wet precipitation method in the presence of pristine (p) or functionalised (f) MWCNTs, and polyvinyl alcohol (PVA) or hexadecyl trimethyl ammonium bromide (HTAB) as the surfactant. The resulting composites were characterised and the diametral tensile strength and compressive strength of the composites were measured. To determine the biocompatibility of the composites, human osteoblast cells (HOB) were proliferated in the presence of the composites for 7 days.

RESULTS

The study revealed that both the MWCNTs and surfactants play a crucial role in the nucleation and growth of the HA. Composites made with f-MWCNTs were found to have better dispersion and better interaction with the HA particles compared to composites with p-MWCNTs. The mechanical strength was improved in all the composites compared to pure HA composites. The biocompatibility study showed minimal LDH activity in the media confirming that the composites were biocompatible. Similarly, the ALP activity confirmed that the cells grown on the composites containing HTAB were comparable to the control whereas the composites containing PVA surfactant showed significantly reduced ALP activity.

CONCLUSIONS

The study shows that the composites made of f-MWCNTs HTAB are stronger than pure HA composites and biocompatible making it a suitable material to study further.

Physicochemical Characterization of Curcumin Loaded Chitosan Nanoparticles: Implications in Cervical Cancer

BACKGROUND

Curcumin is a potent anticancer agent and has great potential efficacy against different types of cancers. A major disadvantage of curcumin, however, is its poor solubility and bioavailability.

OBJECTIVE

The aim of the present work is to synthesize chitosan and curcumin-loaded chitosan nanoparticles and their characterization through various physicochemical methods and cellular uptake in cervical cancer cell line SiHa.

METHOD

Chitosan nanoparticles were synthesized through the method of ionic gelation of chitosan with sodium Tripolyphosphate (TPP). In addition, the internal structure of chitosan nanoparticles and curcumin loaded chitosan nanoparticles were characterized by DLS, UV-Visible spectrophotometer, DSC, LCMS and LDH assay.

RESULTS

The studies presented demonstrate that curcumin-loaded chitosan nanoparticles showed increased uptake in the SiHa cells as compared to free curcumin and chitosan nanoparticles did not show any significant uptake in SiHa cell line. The curcumin-loaded chitosan nanoparticles released more lactate and lower ATP as compared to native curcumin in cervical cancer lines such as SiHa, CaSki and HeLa.

CONCLUSION

Thus, chitosan based curcumin nanoparticles could be used as a potent vector / delivery agent for drug targeting in the treatment of cervical cancer.

Toxicity evaluation and nasal mucosal tissue deposition of dexamethasone-infused mucoadhesive in situ nasal gelling systems

To demonstrate safety of a developed intranasal dexamethasone-infused in situ gelling formulation, quantification of a validated clinical biomarker indicative of cytotoxic potential using a human sinonasal explant model was first confirmed. Systematic cytotoxicity studies using the lactate dehydrogenase (LDH) detection assay revealed no elevation from baseline, in LDH levels, with tissue integrity of explanted human nasal mucosa also maintained; this was further corroborated using tissue histopathological examination. Next, with safety confirmed ex vivo, freshly excised human nasal tissue was utilised to quantify dexamethasone release from the lead sol–gel systems; this being achieved through development and validation of a HPLC-UV analytical method, which reliably quantified controlled therapeutic release and deposition into mucosal tissue. Collectively, these findings indicate promise in the safety of each excipient within the concentrations employed in the functional sol–gel system, complemented by successful and reliable drug release and deposition into human nasal mucosal tissue. These findings pave the way for application of the dexamethasone-based sol–gel system to the extended delivery of corticosteroids to nasal mucosa in the management of localised inflammatory conditions of an acute and chronic nature, such as chronic rhinosinusitis, which can be expected to benefit from controlled and extended drug delivery characteristics imparted by appropriately engineered in situ gelling systems.

Epoxyscillirosidine Induced Cytotoxicity and Ultrastructural Changes in a Rat Embryonic Cardiomyocyte (H9c2) Cell Line

Moraea pallida Bak. (yellow tulp) poisoning is the most important cardiac glycoside-induced intoxication in ruminants in South Africa. The toxic principle, 1α, 2α-epoxyscillirosidine, is a bufadienolide. To replace the use of sentient animals in toxicity testing, the aim of this study was to evaluate the cytotoxic effects of epoxyscillirosidine on rat embryonic cardiomyocytes (H9c2 cell line). This in vitro cell model can then be used in future toxin neutralization or toxico-therapy studies. Cell viability, evaluated with the methyl blue thiazol tetrazolium (MTT) assay, indicated a hormetic dose/concentration response, characterized by a biphasic low dose stimulation and high dose inhibition. Increased cell membrane permeability and leakage, as expected with necrotic cells, were demonstrated with the lactate dehydrogenase (LDH) assay. The LC₅₀ was 382.68, 132.28 and 289.23 µM for 24, 48, and 72 h respectively. Numerous cytoplasmic vacuoles, karyolysis and damage to the cell membrane, indicative of necrosis, were observed at higher doses. Ultra-structural changes suggested that the cause of H9c2 cell death, subsequent to epoxyscillirosidine exposure, is necrosis, which is consistent with myocardial necrosis observed at necropsy. Based on the toxicity observed, and supported by ultra-structural findings, the H9c2 cell line could be a suitable in vitro model to evaluate epoxyscillirosidine neutralization or other therapeutic interventions in the future.

The trypan blue cellular debris assay: a novel low-cost method for the rapid quantification of cell death

Cell death is a common driver of human disease and is frequently studied in a variety of in vitro settings. There currently exists a range of commercially available assays to examine cell death, however, most are costly and require assay-specific experimental conditions that may not be suitable for many cell types. Here, we show that cellular debris occurring as a result of cell death can be used to quantify cell death using trypan blue. Furthermore, we demonstrate that the data generated using this technique are comparable to the widely-used lactate dehydrogenase (LDH) assay. Overall, we describe a novel application for trypan blue, a stain found in most biology laboratories, as a novel and cost-effective method for the quantification of cell death via staining of cell debris.

An appraisal of cuticular wax of Calotropis procera (Ait.) R. Br.: Extraction, chemical composition, biosafety and application

Plastic and polythene as hydrophobic materials become a grave concern due to their non-biodegradable nature, cumbersome recycling and waste management. Cuticular wax derived from Calotropis procera is explored as an eco-friendly and safe hydrophobic material. The effects of duration of exposure to solvent, solvent type, size and side of the leaf on cuticular wax yield have been studied. Leaf with the smallest area (10 cm²-25 cm²) was found to be the most suitable to isolate the wax. GC-MS analysis of the wax revealed that the wax consists of mainly esters, alkane and alkene. Mitochondrial reductase (MTT) and lactate dehydrogenase (LDH) assay have been carried out on M5S cell line at various concentrations and the results indicate that up to 1 μg/ml (acetone as solvent) and 3 μg/ml (chloroform as solvent) use of wax has no toxic effect. To evaluate the hydrophobic potential of the wax in developing hydrophobic paper water regains and contact angle has been measured. The gain in hydrophobicity of the paper is evident from the rise in contact angle (≥90˚) of paper coated with wax. Scanning electron micrograph and FTIR spectra generated physical and chemical evidence of coating of wax on paper.

Cytotoxicity and antigenotoxicity evaluation of acetylshikonin and shikonin

Shikonin (SH) is used as a red pigment for food coloring and cosmetics, and has cytotoxic activity towards cancer cells. However, due to strong toxicity SH has limited potential as an anticancer drug. Acetylshikonin (ASH) is one of the SH derivatives with promising anticancer potential. In present study, we attempted to evaluate and compare the cytotoxicity of SH and ASH towards a normal cell line (V79) and in addition to evaluate their antigenotoxic activity. The evaluation was made with the use of the set of cytotoxicity assays with V79 line and the micronucleus test in vitro performed using clinafloxacin (CLFX), ethyl methanesulfonate (EMS) as direct genotoxins and cyclophosphamide (CPA) as indirect genotoxin. For CPA and EMS the simultaneous protocol was used and for CLFX three different variants were performed: pretreatment, simultaneous, and post-treatment. A higher cytotoxic effect was observed for SH. The EC50 values obtained for SH were approximately twofold lower compared to that of ASH. Moreover, ASH exhibited an antigenotoxic potential against CPA-induced genotoxicity, whereas SH has no activity. However, ASH increased the EMS-induced genotoxicity, when SH exhibited no effect. Both compounds decreased the genotoxicity of CLFX in pretreatment and simultaneous protocol. Based on the results of the present study it can be concluded that ASH is less cytotoxic than SH to normal cells and has comparable antigenotoxic potential.

A biological, fluorescence and computational examination of synthetic coumarin derivatives with antithrombotic potential

BACKGROUND

Scientists still look for new drugs, which have anticoagulant properties. This is so important because existing anticoagulant drugs give many side effects, for example major bleeding. In this study we examined nine coumarin derivatives - candidates to be future antithrombotic drugs, which were synthetized and crystallized in our previous paper.

METHODS

Here we show the fluorescence and fluorescence quenching of coumarin derivatives with di- or trimethoxybenzylamine moieties in C-3 position. All nine compounds were checked by lactate dehydrogenase assay to examine their cytotoxic activity on hepatic cells. We also investigated the other biological properties (bioactivity, drug-likeness and blind docking) using computational tools. Lipophilicity coefficient logP of all obtained compounds was determined using by RP-TLC and compared to theoretical predictions.

RESULTS

The obtained coumarins exhibited low lipophilic character. The substances bound with HSA and did not demonstrate cytotoxicity against isolated liver cells. The most interesting compound (3b) possessed two methoxy- group in 2- and 4-position in benzene ring, ability to interact with two HSA binding sites and probably smaller steric hindrance in comparison to other synthesized derivatives.

CONCLUSIONS

Our present study shows that after examination of fluorescence, cytotoxic activity, lipophilicity, theoretical bioactivity, drug-likeness and blind docking of our synthesized compounds they have potential as antithrombotic medicines and may be candidates to be drugs after further studies.

Demonstration of the lack of cytotoxicity of unmodified and folic acid modified graphene oxide quantum dots, and their application to fluorescence lifetime imaging of HaCaT cells

The authors describe the synthesis of water-soluble and fluorescent graphene oxide quantum dots via acid exfoliation of graphite nanoparticles. The resultant graphene oxide quantum dots (GoQDs) were then modified with folic acid. Folic acid receptors are overexpressed in cancer cells and hence can bind to functionalized graphene oxide quantum dots. On excitation at 305 nm, the GoQDs display green fluorescence with a peak wavelength at ~520 nm. The modified GoQDs are non-toxic to macrophage cells even after prolonged exposure and high concentrations. Fluorescence lifetime imaging and multiphoton microscopy was used (in combination) to image HeCaT cells exposed to GoQDs, resulting in a superior method for bioimaging. Graphical abstract Schematic representation of graphene oxide quantum dots, folic acid modified graphene oxide quantum dots (red), and the use of fluorescence lifetime to discriminate against green auto-fluorescence of HeCaT cells.

Odorous Compounds from Poultry Manure Induce DNA Damage, Nuclear Changes, and Decrease Cell Membrane Integrity in Chicken Liver Hepatocellular Carcinoma Cells

Animal breeding and management of organic wastes pose a serious problem to the health of livestock and workers, as well as the nearby residents. The aim of the present study was to determine the mechanisms of toxicity of selected common odorous compounds from poultry manure, including ammonia, dimethylamine (DMA), trimethylamine (TMA), butyric acid, phenol, and indole. We measured their genotoxic and cytotoxic activity in the model chicken cell line (LMH), in vitro, by comet assay and lactate dehydrogenase assay, respectively. We also made microscopic observations of any morphological changes in these cells by DAPI staining. Four compounds, namely ammonia, DMA, TMA, and butyric acid increased DNA damage in a dose-dependent manner (p < 0.05), reaching genotoxicity as high as 73.2 ± 1.9%. Phenol and indole induced extensive DNA damage independent of the concentration used. Ammonia, DMA, and TMA caused a dose-dependent release of lactate dehydrogenase (p < 0.05). The IC₅₀ values were 0.02%, 0.05%, and 0.1% for DMA, ammonia and TMA, respectively. These compounds also induced nuclear morphological changes, such as chromatin condensation, shrinkage, nuclear fragmentation (apoptotic bodies), and chromatin lysis. Our study exhibited the damaging effects of odorous compounds in chick LMH cell line.

Tyrosine kinase inhibitors as modulators of trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity in breast cancer cell lines

BACKGROUND

Trastuzumab is an anti-HER2 monoclonal antibody (mAb) therapy capable of antibody-dependent cell-mediated cytotoxicity (ADCC) and used in the treatment of HER2+ breast cancer. Through interactions with FcƴR+ immune cell subsets, trastuzumab functions as a passive immunotherapy. The EGFR/HER2-targeting tyrosine kinase inhibitor (TKI) lapatinib and the next generation TKIs afatinib and neratinib, can alter HER2 levels, potentially modulating the ADCC response to trastuzumab. Using LDH-release assays, we investigated the impact of antigen modulation, assay duration and peripheral blood mononuclear cell (PBMC) activity on trastuzumab-mediated ADCC in breast cancer models of maximal (SKBR3) and minimal (MCF-7) target antigen expression to determine if modulating the ADCC response to trastuzumab using TKIs may be a viable approach for enhancing tumor immune reactivity.

METHODS

HER2 levels were determined in lapatinib, afatinib and neratinib-treated SKBR3 and MCF-7 using high content analysis (HCA). Trastuzumab-mediated ADCC was assessed following treatment with TKIs utilising a colorimetric LDH release-based protocol at 4 and 12h timepoints. PBMC activity was assessed against non-MHC-restricted K562 cells. A flow cytometry-based method (CFSE/7-AAD) was also used to measure trastuzumab-mediated ADCC in medium-treated SKBR3 and MCF-7.

RESULTS

HER2 antigen levels were significantly altered by the three TKIs in both cell line models. The TKIs significantly reduced LDH levels directly in SKBR3 cells but not MCF-7. Lapatinib and neratinib augment trastuzumab-related ADCC in SKBR3 but the effect was not consistent with antigen expression levels and was dependent on volunteer PBMC activity (vs. K562). A 12h assay timepoint produced more consistent results. Trastuzumab-mediated ADCC (PBMC:target cell ratio of 10:1) was measured at 7.6±4.7% (T12) by LDH assay and 19±3.2 % (T12) using the flow cytometry-based method in the antigen-low model MCF-7.

CONCLUSIONS

In the presence of effector cells with high cytotoxic capacity, TKIs have the ability to augment the passive immunotherapeutic potential of trastuzumab in SKBR3, a model of HER2+ breast cancer. ADCC levels detected by LDH release assays are extremely low in MCF-7; the flow cytometry-based CFSE/7-AAD method is more sensitive and consistent for the determination of ADCC in HER2-low models.

Examination of the antimalarial potential of experimental aminoquinolines: poor in vitro effect does not preclude in vivo efficacy

Malaria remains a major disease in the developing world and globally is the most important parasitic disease causing significant morbidity and mortality. Because of widespread resistance to conventional antimalarials, including chloroquine (CQ), new drugs are urgently needed. Here we report on the antimalarial efficacy, both in vitro and in vivo, of a series of aminoquinoline derivatives with adamantane or benzothiophene as a carrier. In vitro efficacy was evaluated by a lactate dehydrogenase (LDH) assay in cultures of a CQ-sensitive (3D7) and CQ-resistant (Dd2) strain of Plasmodium falciparum. Of a series of 26 screened compounds, 12 that exerted a growth inhibition rate of ≥50% were further examined in vitro to determine the 50% inhibitory concentration (IC₅₀) values. Nine compounds shown in preliminary experiments to be non-toxic in vivo were evaluated in C57BL/6 mice infected with Plasmodium berghei ANKA strain using a modified Thompson test. All nine compounds examined in vivo prolonged the survival of treated versus untreated mice, four of which afforded ≥60% survival. Most notably, two of these compounds, both with the adamantane carrier, afforded complete cure (100% survival and parasite clearance). Interestingly, one of these compounds had no in vitro effect against the CQ-resistant P. falciparum strain. Better in vivo compared with in vitro results suggest a role for compound metabolites rather than the compounds themselves. The results presented here point to adamantane as a carrier that enhances the antimalarial potential of aminoquinolines.

Kinetic Lactate Dehydrogenase Assay for Detection of Cell Damage in Primary Neuronal Cell Cultures

The aim of many in vitro models of acute or chronic degenerative disorders in the neurobiology field is the assessment of survival or damage of neuronal cells. Damage of cells is associated with loss of outer cell membrane integrity and leakage of cytoplasmic cellular proteins. Therefore, activity assays of cytoplasmic enzymes in supernatants of cell cultures serve as a practicable tool for quantification of cellular injury (Koh and Choi, 1987; Bruer et al., 1997 ). Lactate dehydrogenase (LDH) is such a ubiquitously expressed cytosolic enzyme, which is very stable due to a very long protein half-life (Hsieh and Blumenthal, 1956; Koh and Cotman, 1992; Koh et al., 1995 ).

A traditional poly herbal medicine "Le Pana Guliya" induces apoptosis in HepG2 and HeLa cells but not in CC1 cells: an in vitro assessment

"Le Pana Guliya" (LPG) is a polyherbal formulation which is used to treat different types of cancers in traditional medicine. In this study we describe in vitro efficacy and mechanism of action of LPG on two cancer cell lines (HepG2 and HeLa) compared with a normal cell line CC1. The MTT, LDH assays and protein synthesis were used to study antiproliferative activity of LPG while NO synthesis and GSH content were assayed to determine the oxidative stress exerted by LPG. Rhodamine 123 staining, caspase 3 activity, DNA fragmentation and microscopic examination of cells stained with ethidium bromide/acridine orange were used to identify the apoptosis mechanisms associated with LPG. The LPG showed the most potent antiproliferative effect against the proliferation of HepG2 and HeLa cells with an EC50 value of 2.72 ± 1.36 and 19.03 ± 2.63 µg/mL for MTT assay after 24 h treatment respectively. In contrast, CC1 cells showed an EC50 value of 213.07 ± 7.71 µg/mL. Similar results were observed for LDH release. A dose dependent decrease in protein synthesis was shown in both cancer cell types compared to CC1 cells. The reduction of GSH content and elevation of cell survival with exogenous GSH prove that the LPG act via induction of oxidative stress. LPG also stimulates the production of NO and mediates oxidative stress. Rhodamine 123 assay shows the mitochondrial involvement in cell death by depletion of Δψ inducing downstream events in apoptosis. This results in increase in caspase-3 activity eventually DNA fragmentation and LPG induced apoptotic cell death. In conclusion the present study suggested that the LPG exerted an anticancer activity via oxidative stress dependent apoptosis. Therefore present study provides the scientific proof of the traditional knowledge in using LPG as an anticancer agent.

Detoxification and function of immature tomato

α-Tomatine and chlorophyll (a and b) decreased, and β-carotene and lycopene increased with ripening of tomatoes. α-Tomatine was localised in peel of immature green tomatoes. The dose-response curve of α-tomatine determined by WST-1 (water soluble tetrazolium) assay was the same as that by LDH (lactate dehydrogenase) assay, suggesting that the cytotoxicity of α-tomatine depends on the destruction of plasma membrane. Immature green tomatoes had little cytotoxic effect after one month-incubation with 25% ethanol or 4.5% acetate at 7°C, and α-tomatine was decomposed by crude enzymes extracted from immature green tomatoes. Immature green tomatoes incubated with 4.5% acetic acid inhibited the accumulation of lipid in adipocytes. From the above facts the detoxification and the anti-obesity effect of immature green tomatoes are expected to be controlled by the removal of peel, the enzymatic decomposition or the incubation with 4.5% acetate or 25% ethanol.

Redox activity and in vitro bioactivity of the water-soluble fraction of urban particulate matter in relation to particle size and chemical composition

Chemical and toxicological characterization of the water-soluble fraction of size-segregated urban particulate matter (PM) (<0.49, 0.49-0.97, 0.97-1.5, 1.5-3.0, 3.0-7.2 and >7.2 μm) was carried out at two urban sites, traffic and urban background, during the cold and the warm period. Chemical analysis of the water-soluble PM fraction included ionic species (NO3(-), SO4(2-), Cl(-), Na(+), NH4(+), K(+), Mg(2+), Ca(2+)), water-soluble organic carbon (WSOC), and trace elements (Al, As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Zn, Pt, Pd, Rh, Ru, Ir, Ca, and Mg). The dithiothreitol (DTT) assay was employed for the abiotic assessment of the oxidative PM activity. Cytotoxic responses were investigated in vitro by applying the mitochondrial dehydrogenase (MTT) and the lactate dehydrogenase (LDH) bioassays on human lung cells (MRC-5), while DNA damage was estimated by the single cell gel electrophoresis assay, known as Comet assay. The correlations between the observed bioactivity responses and the concentrations of water-soluble chemical PM constituents in the various size ranges were investigated. The results of the current study corroborate that short-term bioassays using lung human cells and abiotic assays, such as the DTT assay, could be relevant to complete the routine chemical analysis and to obtain a preliminary screening of the potential effects of PM-associated airborne pollutants on human health.

PAMAM dendrimer with 4-carbomethoxypyrrolidone--in vitro assessment of neurotoxicity

Cytotoxicity of cationic amino-terminated PAMAM dendrimer and modified PAMAM-pyrrolidone dendrimer was compared. LDH assay and cell visualization technique were employed. Mouse embryonic hippocampal cells (mHippoE-18) were used. The experiments were performed in FBS-deprived medium. Pyrrolidone-modification significantly diminished toxicity of PAMAM dendrimer. The absence of FBS did not reveal significant impact on the toxic effect. Results from LDH assay and MTT test were in good consistency. Low cytotoxicity of PAMAM-pyrrolidone dendrimer increases reliability of the results showing a small impact of this dendrimer on cell viability.

Synthesis, and In-vitro Cytotoxicity Studies of a Series of Triazene Derivatives on Human Cancer Cell Lines

Compounds containing triazene ring structure are cytotoxic agents and clinically used as antitumor alkylating agents. In this study, a series of triazene derivatives holding alkyl and aryl moieties were synthesized and proved to be potent cytotoxic agents in-vitro particularly against eight cancer cell lines (PC3, HT29, Hela, HL60, Jurkat, K562, MCF7, HepG2) and a non-cancerous cell line (HUVEC). The cytotoxic activity was assessed using two methods, LDH assay, and trypan blue exclusion. Some of the triazene derivatives showed cytotoxic activity more than temozolomide (TMZ) as the reference drug. The synthesized triazenes showed marked cytotoxicity effects on all eight cancer cell lines. Among the compounds synthesized, 1,3-bis(2-ethoxyphenyl)triazene C had unique efficacy and selectivity so that it had IC50 between 0.560-3.33 μM on cancer cell lines and 12.61 μM on normal cell line (HUVEC). 1-(4-nitrophenyl)-3-(2-hydroxyethyl)triazene E shows weaker effect on cancer cell lines than the other compounds having IC50 between 3-15.54 μM.

Anticancer and anti-inflammatory activities of shallot (Allium ascalonicum) extract

INTRODUCTION

Alliumplants are an important part of the diet of many populations and there is a long-held belief in their health-enhancing properties such as cancer prevention. In this study, the anticancer and anti-inflammatory activities of the aqueous extract of the Allium ascalonicum bulbs have been studied.

MATERIAL AND METHODS

The antiproliferative and anti-growth activity of the aqueous extract of A. ascalonicum was examined in vitro on different tumor cell lines. Furthermore, the acetic acid-induced vascular permeability as an in vivo assay was used for studying anti-inflammatory activity of the extract.

RESULTS

The aqueous extract of A. ascalonicum had the most anti-growth activity on the cancer cell lines; Jurkat and K562 against Wehi 164 with lower cytotoxic preference. The extract also showed much less cytotoxicity against the normal cell (HUVEC) line and significant anti-inflammatory activity in vivo.

CONCLUSIONS

It is of interest that the extract of this plant has shown much less cytotoxicity against the normal cell line, and, if this also occurs in vivo, the use of this plant clinically for the treatment of cancer patients would have some scientific support. The results of these assays indicated that A. ascalonicum can be a candidate for prevention and treatment of many diseases related to inflammation and malignancy.