Merremia emarginata Extract Potentiates the Inhibition of Human Colon Cancer Cells (HT-29) via the Modulation of Caspase-3/Bcl-2-Mediated Pathways

Background This study investigates Merremia emarginata's curative effectiveness against colon cancer cells. M. emarginata, often known as Elika jemudu, is a Convolvulaceae family plant. The inhibitory ability of anticancer herbal extracts against cancer cell growth and mediators is tested.  Aim This study aims to evaluate the potent anticancer activity of M. emarginata against colon cancer cell line (HT-29). Materials and methods M. emarginata leaves were gathered and processed using solvent extraction. Anticancer activity on colon cancer cells was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and cysteine aspartic acid protease-3 (caspase 3), B-cell lymphoma 2 (Bcl-2), and B-cell lymphoma-extra large (Bcl-xL) mRNA expressions. The data was reported as the mean ± SD of three separate experiments done in triplicate. The statistical analysis was carried out using one-way analysis of variance (ANOVA), with a p-value less than 0.05 indicating statistical significance. Results The cell viability test showed a gradual decrease in cell growth and proliferation as the concentration increased. The ethanolic extract of M. emarginata was found to be cytotoxic against colon caller cell lines. The extract was able to induce apoptosis of cancer as revealed by Bcl-2, Bcl-xL, and caspase-3 (p<0.05 and p<0.001) signaling pathways. Conclusion M. emarginata extracts showed good anticancer activity against colon cancer cell lines. Further work is required to establish and identify the chemical constituent responsible for its anticancer activity.

Cytotoxicity Evaluation of Various Composite Resin Materials: An In Vitro Study

Aim This study aimed to determine and compare the cytotoxicity of light-cured composite resin (Enlight light cure composite (Ormco, Glendora, California, USA)), light-cured acrylic resin (Orthocryl LC (Dentaurum, Ispringen, Germany)), and the self-cure acrylic (DPI RR cold cure acrylic (Dental Products of India, Bombay Burmah Trading Corporation Ltd., Mumbai, India)) material and to determine which component is best to be used for the purpose of nasal stent fabrication in the nasoalveolar molding (NAM) technique for cleft therapy. Methods Circular discs made from Enlight light cure composite, Orthocryl LC, and self-cure acrylic were submerged for 24 hours in gingival fibroblast media (three discs of each material) and control medium (three discs of each material) that were both contained in plates. After analyzing the optical densities of the plates, the cytotoxicity of the products was assessed by measuring cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The compiled data was analyzed using IBM SPSS Statistics for Windows, V. 23.0 (IBM Corp., Armonk, NY). The normality of the data was evaluated using the Shapiro-Wilk test. One-way analysis of variance (ANOVA) and pairwise comparison made with Tukey's honestly significant difference (HSD) post hoc test with a significance level (p) of 0.05 were considered. Results The percentage of cell viability was between 80% and 150%. A significant mean difference was noted in the cell viability between the three groups (p=0.009). High mean cell viability was seen in Orthocryl LC. However, there was no significant mean difference between Orthocryl LC and Enlight light cure composite material (p=0.854). Conclusion Both Orthocryl LC and Enlight light cure composite materials are less cytotoxic when compared to the self-cure acrylic resin material and can be used to fabricate the nasal stent component for infants with cleft defects, undergoing NAM procedure.

Evaluation of Cytotoxicity of 4-Hydroxycinnamic Acid Using Tetrazolium Bromide Assay and Zebrafish Embryotoxicity: An In-Vitro Study

Aim This study aimed to evaluate the cytotoxicity of a novel compound, 4-hydroxycinnamic acid (4-HCA), with the help of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and zebrafish embryotoxicity. Materials and methods In this in vitro study, MTT fibroblast assays using dental pulp stem cells, which were cultured in Modified Eagle's Medium or Dulbecco's Modified Eagle Medium, and zebrafish cytotoxicity and embryotoxicity were done to evaluate the cytotoxicity of the novel compound 4-HCA. The data was analyzed by plotting cell number versus absorbance, allowing quantitation of changes in cell proliferation. Results 4-HCA (40 μl) showed acceptable levels of cell viability according to the American Society for Testing and Materials standards. Cell viability is reduced with increased exposure time and concentrations of 4-HCA. Similarly, the cytotoxicity assessment in zebrafish (Danio rerio) showed an acceptable range of toxicity levels in embryonic stages used to evaluate the mortality rate of zebrafish embryos. Conclusion Considering the constraints of this research, it can be deduced that hydroxycinnamic acid at a concentration of 40 μl was non-toxic. The findings from the MTT assay indicated a correlation between the concentration and the toxicity of the compound. Likewise, the zebrafish test demonstrated minimal toxicological effects.

Analyzing the Antihyperglycemic Effect of Cissus quadrangularis and Bacopa monnieri on 3T3-L1 Cell Lines

Background Cissus quadrangularis is a perennial shrub of the grape family. Other names for it include devil's backbone, veld grape, and pirandai (Tamil). Bacopa monnieri, a perennial plant, is native to wetlands in eastern and southern India. The 3T3-L1 cell line, which was created from 3T3 cells, was used in the scientific study. The current study's purpose is to evaluate the antihyperglycemic benefits of B. monnieri and C. quadrangularis, which will be added to the current arsenal of efficient herbal hypoglycemic medications. Aim To analyze and compare the anti-hyperglycaemic effects of the two plant extracts, C. quadrangularis and B. monnieri using a 3T3-L1 cell line. Materials and methods C. quadrangularis seeds were gathered, and extraction was conducted. The B. monnieri plant was harvested, and a rotary evaporator was used to extract the flower. Adipocyte cells were obtained from NCCS, Pune. A CO2 incubator was used to incubate the cells. The MTT assay and gene expression analysis were done on the cell line samples. Results The antihyperglycemic effects of C. quadrangularis IRS mRNA levels of 0.7 and AKT mRNA levels of 0.7 are compared to B. monnieri IRS1 mRNA levels of 0.6 and AKT mRNA levels of 0.6 to build better diabetic treatments. The antihyperglycemic benefits of C. quadrangularis levels of IRS mRNA and AKT mRNA are compared to the influence of B. monnieri IRS1 mRNA and AKT mRNA on the development of better diabetic drugs. Conclusion Comparing the effects of C. quadrangularis and B. monnieri on the 3T3 cell line by gene expression of IRS mRNA and AKT mRNA suggests that the particular AKT downregulation shows that insulin suppresses gluconeogenesis and C. quadrangularis inhibits hyperglycemia in 3T3-L1 cells, while research on in vitro rats suggests that B. monnieri may minimize the signs and symptoms of diabetes via enhancing IRS1/AKT signaling.

Anticancer Property of Digera muricata Leaf Extract: An In Vitro Study

Aim The aim was to evaluate the anticancer potential of Digera muricata ethanolicleaf extract on MG-63 osteosarcoma cell lines. Materials and methods The anti-cancer properties of Digera muricata ethanolic leaf extract were evaluated on osteosarcoma cell lines using 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the morphological changes in MG-63 cells were assessed after 24 hours using microscopic observation. Additionally, fluorescence microscopy was employed to evaluate the apoptotic changes after acridine orange/ethidium bromide (AO/EtBr) dual staining. Results The MTT assay revealed a dose-dependent cell death. The cell viability decreased with increase in concentrations of the extract, The cell viability was 89.98 ± 4.89 percentage at 25 μg/ml and 15.64 ± 3.64 percentage at 200 μg/ml concentrations. A concentartion of 116.95 μg/ml showed 50% inhibition (IC50). The morphological and dual staining studies also showed the extract's effectiveness in inducing apoptosis. Conclusion The ethanolic leaf extract of D. muricata could impart good antiproliferative activity in MG-63 cell lines. The extract could also induce apoptosis and hence, it may be considered as a potential anticancer agent for the development of drug formulation for the treatment of osteosarcoma.

A Look Into the Cytotoxicity of Composite Fillings: Friend or Foe?

Dental resin composites are widely used restorative materials in dentistry for the treatment of carious and non-carious lesions as well as pit and fissure sealants, cavity liners, and endodontic sealers. They consist of two parts: an organic resin matrix and an inorganic/organic filler. The organic resin matrix phase is made up of multifunctional monomers and light-sensitive initiators, while the inorganic/organic filler phase is made up of micro/nano-sized fillers that primarily serve as reinforcement. Despite being a very promising dental material, its monomeric component has some drawbacks. It is well known for leaching out during incomplete polymerization, which can result in cytotoxicity. Bis-GMA (bisphenol A-glycidyl methacrylate) is the most cytotoxic of all monomeric components that exhibit synthetic estrogenic effects. The purpose of this article is to assess the cytotoxic effects of dental composite, understand the possible mechanism behind them, and explore ways to screen for and reduce this harmful effect, as well as shed light on its future prospects.

Assessment of Therapeutic Bio-Activity of Cinnamoyl Sulfonamide Hydroxamate in Squamous Cell Carcinoma

Background Cancer is the second most common cause of death. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Many treatment modalities such as chemotherapy, radiotherapy, surgery, and immunotherapy are emerging but still, the patients' quality of life is questionable. Despite the advances in therapeutic approaches, the percentages of morbidity and mortality of OSCC have not improved significantly during the last 30 years. Treatment using natural products can act as a potent anti-cancer agent with reduced adverse effects. Cinnamic acid derivatives exhibit anti-cancer potential through histone deacetylase inhibitor (HDAC) enzyme inhibition. Methodology In an experimental study design, cinnamoyl hydroxamate derivatives were prepared. The structure was confirmed using ultraviolet-visible spectroscopy (UV-Vis), nuclear magnetic resonance (NMR), infrared spectroscopy, and mass spectrophotometry. An in-vitro antioxidant assay using nitric oxide scavenging and reducing power assay was done and an in-vitro cytotoxic (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay and viability assay were carried out using tryphan blue dye. Results Statistical analysis was performed using SPSS (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp). Cinnamoyl hydroxamate derivatives were obtained and named as compounds 3a (E)-N-Hydroxy-3-(4-(N-(phenyl bromo) sulfamoyl) phenyl) acrylamide-) and 3b ((E)-N-Hydroxy-3-(4-(N-(phenyl nitro) sulfamoyl) phenyl) acrylamide). In the nitric oxide scavenging assay, compound 3a showed good antioxidant activity than 3b. Reducing power assay was higher in 3a compared to 3b. Cell viability using tryphan blue exhibited a concentration decrease in % cell viability with an increase in the concentration of human oral cavity squamous cell carcinoma cell line (OECM 1), a unique head and neck squamous carcinoma cell line (UM SCC 6) & human oral squamous cell carcinoma forming metastatic foci (HSC 3) cell lines. Conclusion The results of the present study revealed that the study compounds play a vital role in the up-regulation of apoptotic pathways and regulation of terminal differentiation pathways. The compounds showed good anti-oxidant and anti-cancer activities in lesser concentrations, hence they can be used as a therapeutic agent for oral squamous cell carcinoma.

Antiproliferative Action of Methanolic Petiole Extract of Eichhornia Crassipes on Human Prostate Adenocarcinoma Cell Line: An In Vitro Study

BACKGROUND

An increasing number of people are turning to herbal medicines in their search for innovative pharmaceuticals since they are effective treatments for a wide variety of conditions and traditional herbs are rich in bioactive chemicals. In this study, we looked at whether or not a petiole extract of Eichhornia crassipes preserved in methanol inhibited the proliferation of prostate cancer (PC3) cell lines.

MATERIALS AND METHODS

Lakes in Ezhikkara, Ernakulum, Kerala, were the source of E. crassipes. Soxhlet extraction was used to create the extract. 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the cell viability of methanolic petiole extract at various concentrations. Mean and standard deviation was used to determine absorbance scores. Utilizing probit analysis, we determined the IC50 value. The descriptive statistics to measure the percent of viable cells along with the regression equation were calculated using SPSS.

RESULTS

It has been shown that the methanol extract significantly impacted PC3 cell lines' capacity to survive. It was also determined that increasing the medication concentration resulted in a decrease in cell viability. The percentage of living cells was measured after being exposed to methanol extracts at concentrations of 12.5 μg/ml, 25 μg/ml, 50 μg/ml, 100 μg/ml, and 200 μg/ml, and found to be 95.13, 85.88, 76.12, 64.33, and 53.62 percent, respectively. With IC50 values of 199.488 g/ml, it was shown that methanolic petiole extracts of E. crassipes are cytotoxic. Using probit analysis, we determined that the regression equation is y = -0.2051x + 90.915, with an R2 value of 0.893.

CONCLUSION

As a result of its chemotherapeutic properties, the E. crassipes petiole extract has the potential to be employed in therapeutic applications, with the ultimate goal of bettering prostate cancer management practices and clinical results by drastically lowering cell viability. The study's results may pave the way for fresh chemotherapeutic approaches to be developed for the treatment of androgen-independent prostate cancer.

Antioxidant and cytoprotective effects of avocado oil and extract (Persea americana Mill) against rotenone using monkey kidney epithelial cells (Vero)

Oxidative stress is known to be involved in development of numerous diseases including cardiovascular, respiratory, renal, kidney and cancer. Thus, investigations that mimic oxidative stress in vitro may play an important role to find new strategies to control oxidative stress and subsequent consequences are important. Rotenone, widely used as a pesticide has been used as a model to simulate oxidative stress. However, this chemical was found to produce several diseases. Therefore, the aim of this study was to investigate the antioxidant and cytoprotective effect of avocado (Persea americana Mill) extract and oil in monkey kidney epithelial cells (VERO) exposed to rotenone. VERO cells were exposed to IC₅₀ of rotenone in conjunction with different concentrations of avocado extract and oil (ranging from 1 to 1000 µg/ml), for 24 hr. Subsequently, cell viability and oxidative metabolism were assessed. Data demonstrated that avocado extract and oil in the presence of rotenone increased cellular viability at all tested concentrations compared to cells exposed only to rotenone. In addition, extract and avocado oil exhibited antioxidant action as evidenced by decreased levels of reactive oxygen species (ROS), superoxide ion, and lipid peroxidation, generated by rotenone. Further, avocado extract and oil appeared to be safe, since these compounds did not affect cell viability and or generate oxidative stress. Therefore, avocado appears to display a promising antioxidant potential by decreasing oxidative stress.

Impact of magnetic immobilization on the cell physiology of green unicellular algae Chlorella vulgaris

Cell immobilization on the magnetic nanoparticles (MNPs) and magnetic harvesting is a novel approach for microalgal cells separation. To date, the effect of these nanoparticles on microalgal cells was only studied over a short period of time. More studies are hence needed for a better understanding of the magnetic harvesting proposes or environmental concerns relating to long-term exposure to nanoparticles. In this study, the impact of various concentrations of MNPs on the microalgal cells growth and their metabolic status was investigated over 12 days. More than 60% reduction in mitochondrial activity and pigments (chlorophyll a, chlorophyll b, and carotenoids) content occurred during the first 6 days of exposure to ≥50 µg/mL nanoparticles. However, more than 50% growth inhibitory effect was seen at concentrations higher than 400 µg/mL. Exposure to MNPs gradually induced cellular adaptation and after about 6 days of exposure to stress generating concentrations (˂400 µg/mL) of IONs, microalgae could overcome the imposed damages. This work provides a better understanding regarding the environmental impact of MNPs and appropriate concentrations of these particles for future algal cells magnetic immobilization and harvesting.

Dual-energy CT imaging of nasopharyngeal cancer cells using multifunctional gold nanoparticles

The purpose of this study is to measure the concentration of gold nanoparticles (AuNPs) attached to folic acid through cysteamin as the linker (FA-Cys-AuNPs) and AuNPs in KB human nasopharyngeal cancer cells using dual-energy CT (DECT). In this study, nanoparticles with a size of ∼15 nm were synthesized and characterised using UV-Vis, TEM, FTIR and ICP-OES analyses. The non-toxicity of nanoparticles was confirmed by MTT assay under various concentrations (40-100 µg/ml) and incubation times (6, 12 and 24 h). To develop an algorithm for revealing different concentrations of AuNPs in cells, a corresponding physical phantom filled with 0.5 ml vials containing FA-Cys-AuNPs was used. The CT scan was performed at two energy levels (80 and 140 kVp). One feature of DECT is material decomposition, which allows separation and identification of different elements. The values obtained from the DECT algorithm were compared with values quantitatively measured by ICP-OES. Cells were also incubated with AuNPs and FA-Cys-AuNPs at different concentrations and incubation times. Subsequently, by increasing the incubation time in the presence of FA-Cys-AuNPs, in comparison with AuNPs, DECT pixels were increased. Thus, FA-Cys-AuNPs could be a suitable candidate for targeted contrast agent in DECT molecular imaging of nasopharyngeal cancer cells.

Silver using Centella asiatica leaf extract: apoptosis induction in MCF-7 breast cancer cell line

The aim of this study was to green synthesised silver nanoparticles (AgNPs) using Centella asiatica leaf extract and investigate the cytotoxic and apoptosis-inducing effects of these nanoparticles in MCF-7 breast cancer cell line. The characteristics and morphology of the green synthesised AgNPs were evaluated using transmission electron microscopy, scanning electron microscopy, UV-visible spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The MTT assay was used to investigate the anti-proliferative activity of biosynthesised nanoparticles in MCF-7 cells. Apoptosis test was performed using flow cytometry and expression of caspase 3 and 9 genes. The spherical AgNPs with an average size of 19.17 nm were synthesised. The results showed that biosynthesised AgNPs exhibited cytotoxicity, anti-cancer, apoptosis induction, and increased expression of genes encoding for caspases 3 and 9 in MCF-7 cancer cells in a concentration- and time-dependent manner. It seems that green synthesised AgNPs have potential uses for pharmaceutical industries.

Green synthesis of silver nanoparticles using Mentha pulegium and investigation of their antibacterial, antifungal and anticancer activity

A simple and eco-friendly method for efficient synthesis of stable colloidal silver nanoparticles (AgNPs) using Mentha pulegium extracts is described. A series of reactions was conducted using different types and concentrations of plant extract as well as metal ions to optimize the reaction conditions. AgNPs were characterized by using UV-vis spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering, zetasizer, energy-dispersive X-ray spectroscopy (EDAX) and Fourier transform infrared spectroscopy (FTIR). At the optimized conditions, plate shaped AgNPs with zeta potential value of -15.7 and plasmon absorption maximum at 450 nm were obtained using high concentration of aqueous extract. Efficient adsorption of organic compounds on the nanoparticles was confirmed by FTIR and EDAX. The biogenic AgNPs displayed promising antibacterial activity on Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes. The highest antibacterial activity of 25 µg mL-1 was obtained for all the strains using aqueous extract synthesized AgNPs. The aqueous extract synthesised AgNPs also showed considerable antifungal activity against fluconazole resistant Candida albicans. The cytotoxicity assay revealed considerable anticancer activity of AgNPs on HeLa and MCF-7 cancer cells. Overall results indicated high potential of M. pulegium extract to synthesis high quality AgNPs for biomedical applications.

Synthesis of gold and silver nanoparticles using Mukia maderaspatna plant extract and its anticancer activity

The present investigation reveals the in vitro cytotoxic effect of the biosynthesised metal nanoparticles on the MCF 7 breast cancer cell lines. The gold and silver nanoparticles were synthesised through an environmentally admissible route using the Mukia Maderaspatna plant extract. Initially, the biomolecules present in the plant extract were analysed using phytochemical analysis. Further, these biomolecules reduce the metal ion solution resulting from the formation of metal nanoparticles. The reaction parameters were optimised to control the size of nanoparticles which were confirmed by UV visible spectroscopy. Various instrumental techniques such as Fourier transform-infrared spectroscopy, high resolution transmission electron microscopy, energy dispersive X-ray and scanning electron microscopy were employed to characterise the synthesised gold and silver nanoparticles. The synthesised gold and silver nanoparticles were found to be 20-50 nm and were of different shapes including spherical, triangle and hexagonal. MTT and dual staining assays were carried out with different concentrations (1, 10, 25, 50 and 100 µg/ml) of gold and silver nanoparticles. The results show that the nanoparticles exhibited significant cytotoxic effects with IC 50 value of 44.8 µg/g for gold nanoparticles and 51.3 µg/g for silver nanoparticles. The observations in this study show that this can be developed as a promising nanomaterial in pharmaceutical and healthcare sector.

Kinetic properties of Streptomyces canarius L- Glutaminase and its anticancer efficiency

L-glutaminase was produced by Streptomyces canarius FR (KC460654) with an apparent molecular mass of 44 kDa. It has 17.9 purification fold with a final specific activity 132.2 U/mg proteins and 28% yield recovery. The purified L-glutaminase showed a maximal activity against L-glutamine when incubated at pH 8.0 at 40 °C for 30 min. It maintained its stability at wide range of pH from 5.0 11.0 and thermal stable up to 60 °C with Tm value 57.5 °C. It has high affinity and catalytic activity for L-glutamine (Km 0.129 mM, Vmax 2.02 U/mg/min), followed by L-asparagine and L-aspartic acid. In vivo, L-glutaminase showed no observed changes in liver; kidney functions; hematological parameters and slight effect on RBCs and level of platelets after 10 days of rabbit's injection. The anticancer activity of L-glutaminase was also tested against five types of human cancer cell lines using MTT assay in vitro. L-glutaminase has a significant efficiency against Hep-G2 cell (IC50, 6.8 μg/mL) and HeLa cells (IC50, 8.3 μg/mL), while the growth of MCF-7 cells was not affected. L-glutaminase has a moderate cytotoxic effect against HCT-116 cell (IC50, 64.7 μg/mL) and RAW 264.7 cell (IC50, 59.3 μg/mL).

Synthesis and biological evaluation of new pyridone-annelated isoindigos as anti-proliferative agents

A selected set of substituted pyridone-annelated isoindigos 3a-f has been synthesized via interaction of 5- and 6-substituted oxindoles 2a-f with 6-ethyl-1,2,9-trioxopyrrolo[3,2-f]quinoline-8-carboxylic acid (1) in acetic acid at reflux. Among these isoindigos, the 5'-chloro and 5'-bromo derivatives 3b and 3d show strong and selective antiproliferative activities against a panel of human hematological and solid tumor cell-lines, but not against noncancerous cells, suggesting their potential use as anticancer agents. In all the tested cell lines, compound 3b was a 25%-50% more potent inhibitor of cell growth than 3d, suggesting the critical role of the substitution at 5'-position of the benzo-ring E. The IC50 values after 48 hours incubation with the 5'-chloro compound 3b were 6.60 µM in K562, 8.21 µM in THP-1, 8.97 µM in HepG2, 11.94 µM in MCF-7 and 14.59 µM in Caco-2 cancer cells, while the IC50 values in noncancerous HEK-293 and L-929 were 30.65 µM and 40.40 µM, respectively. In addition, compound 3b induced higher levels apoptosis in K562 cells than 3d, as determined by annexin V/7-AAD flowcytometry analysis. Therefore, further characterization of the antitproliferative mechanisms of compounds 3b and 3d may provide a novel chemotherapeutic agents.

Striking reduction of amyloid plaque burden in an Alzheimer's mouse model after chronic administration of carmustine

BACKGROUND

Currently available therapies for Alzheimer's disease (AD) do not treat the underlying cause of AD. Anecdotal observations in nursing homes from multiple studies strongly suggest an inverse relationship between cancer and AD. Therefore, we reasoned that oncology drugs may be effective against AD.

METHODS

We screened a library of all the FDA-approved oncology drugs and identified bis-chloroethylnitrosourea (BCNU or carmustine) as an effective amyloid beta (Aβ) reducing compound. To quantify Aβ levels, Chinese hamster ovary (CHO) cells stably expressing amyloid precursor protein 751WT (APP751WT) called 7WD10 cells were exposed to different concentrations of BCNU for 48 hours and the conditioned media were collected. To detect Aβ the conditioned media were immunoprecipitated with Ab9 antibody and subjected to immunoblot detection. Amyloid plaques were quantified in the brains of a mouse model of AD after chronic exposure to BCNU by thoflavin S staining.

RESULTS

BCNU decreased normalized levels of Aβ starting from 5 μM by 39% (P < 0.05), 10 μM by 51% (P < 0.01) and 20 μM by 63% (P < 0.01) in CHO cells compared to a control group treated with butyl amine, a structural derivative of BCNU. Interestingly, soluble amyloid precursor protein α (sAPPα) levels were increased to 167% (P < 0.01) at 0.5 μM, 186% (P < 0.05) at 1 μM, 204% (P < 0.01) at 5 μM and 152% (P < 0.05) at 10 μM compared to untreated cells. We also tested the effects of 12 structural derivatives of BCNU on Aβ levels, but none of them were as potent as BCNU. BCNU treatment at 5 μM led to an accumulation of immature APP at the cell surface resulting in an increased ratio of surface to total APP by 184% for immature APP, but no change in mature APP. It is also remarkable that BCNU reduced Aβ generation independent of secretases which were not altered up to 40 μM. Interestingly, levels of transforming growth factor beta (TGFβ) were increased at 5 μM (43%, P < 0.05), 10 μM (73%, P < 0.01) and 20 μM (92%, P < 0.001). Most significantly, cell culture results were confirmed in vivo after chronic administration of BCNU at 0.5 mg/kg which led to the reduction of Aβ40 by 75% and amyloid plaque burden by 81%. Conversely, the levels of sAPPα were increased by 45%.

CONCLUSIONS

BCNU reduces Aβ generation and plaque burden at non-toxic concentrations possibly through altered intracellular trafficking and processing of APP. Taken together these data provided unequivocal evidence that BCNU is a potent secretase-sparing anti-Aβ drug. See related commentary article here http://www.biomedcentral.com/1741-7015/11/82.

Investigation of In Vitro Bone Cell Adhesion and Proliferation on Ti Using Direct Current Stimulation

Our objective was to establish an in vitro cell culture protocol to improve bone cell attachment and proliferation on Ti substrate using direct current stimulation. For this purpose, a custom made electrical stimulator was developed and a varying range of direct currents, from 5 to 25 µA, were used to study the current stimulation effect on bone cells cultured on conducting Ti samples in vitro. Cell-materials interaction was studied for a maximum of 5 days by culturing with human fetal osteoblast cells (hFOB). The direct current was applied in every 8 h time interval and the duration of electrical stimulation was kept constant at 15 min for all cases. In vitro results showed that direct current stimulation significantly favored bone cell attachment and proliferation in comparison to nonstimulated Ti surface. Immunochemistry and confocal microscopy results confirmed that the cell adhesion was most pronounced on 25 µA direct current stimulated Ti surfaces as hFOB cells expressed higher vinculin protein with increasing amount of direct current. Furthermore, MTT assay results established that cells grew 30% higher in number under 25 µA electrical stimulation as compared to nonstimulated Ti surface after 5 days of culture period. In this work we have successfully established a simple and cost effective in vitro protocol offering easy and rapid analysis of bone cell-materials interaction which can be used in promotion of bone cell attachment and growth on Ti substrate using direct current electrical stimulation in an in vitro model.

Retracted: Luciferase-transfected colon adenocarcinoma cell line (DLD-1) for use in Orthotopic Xenotransplantation studies

BACKGROUND

Renilla Luciferase reporter gene (rLuc) GL4.82 and GL4.13 promoter are key player in transfection, but precise knowledge of its targets in colon cancer remains limited. The aim of this study was to characterize the best transfection technique to produce a stable transfected colon DLD1 (colorectal adenocarcinoma cell line), therefore imaging based approaches were employed.

RESULTS

DLD1 cells were transfected with a Plasmid (SV40-RLuc) carrying Renilla luciferase under the control of the SV-40 promoter, by using two different transfection techniques. Cells expressing the required DNA were isolated after antibiotic (Puramycin) selection. Clones of DLD-1/SV40-RLuc were produced using two different techniques (96 well plates and Petri dish) and their florescence intensity was recorded using IVIS machine (Calliper Life Sciences, Hopkinton, USA). Both techniques were characterized with the help of serial dilution technique. Results from this study substantiated that electroporation is the best. As expected, clones varied in their specific luciferase activity along with the dilutions. With the increase in cell concentration increase in intensity of florescence was recorded.

CONCLUSIONS

Based on the results we are confident that this transfected cell line DLD-1/SV40-RLuc (colorectal adenocarcinoma cell line) is the best for further Orthotopic Xenotransplantation Studies and in-vivo experiments as well. Investigation shows that DLD1/SV-rLuc cells have gained little bit resistance against both drugs therefore further study is suggested to know the reasons.

Single-cell suspension assay with an MTT end point is useful for evaluating the optimal adjuvant chemotherapy for advanced gastric cancer

One hundred and forty-eight patients with gastric cancer admitted to Keio University Hospital between July 1988 and October 1992 underwent resection of the primary lesion, as well as single-cell suspension assay of fresh surgical materials with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay) for chemosensitivity evaluation. Fifty patients with histologically stage III or IV gastric cancer were enrolled in this study, among whom 10 received no chemotherapy after surgery while 40 received chemotherapy at equivalent dose levels after surgery. The patients given chemotherapy were divided into two groups consisting of an "Adapted" group treated with at least one agent identified as effective by the assay, and a "Non-adapted" group treated with agents to which the cells were not sensitive in the assay, in order to identify the optimal cut-off inhibition rate (IR) in MTT assay for evaluation of the appropriate adjuvant cancer chemotherapy after surgery. A cut-off IR of 30% was optimal for differentiating the survival rates between the "Adapted" and "Non-adapted" groups. Patients treated with drugs which showed more than 30% IR on their surgical specimens showed a better survival rate than patients treated with drugs which were ineffective in the assay.

Flow cytometric analysis of early steps in development of adriamycin resistance in a human gastric cancer cell line

We have established a low-level adriamycin (ADM)-resistant human gastric cancer cell line (MKN45R) from the parental cell line (MKN45) by exposure to stepwise increases of ADM concentration (final concentration, 0.026 microgram/ml). The purpose of this study was to identify the early steps in the development of ADM resistance in MKN45R by flow cytometric (FCM) analysis. Comparison of the concentration required for 50% growth inhibition, determined by a tetrazolium-based colorimetric assay, showed that MKN45R was about 2.6-fold more resistant to ADM than MKN45. However, the inhibition index values were 89.5% for MKN45 and 86.4% for MKN45R, respectively, showing that ADM was judged to be "effective" against both cell lines. On the other hand, cell kinetic analysis by FCM revealed that the increase of the ratio of G2M accumulation induced by ADM treatment was significantly lower (P < 0.01) in MKN45R. Moreover, the efflux of ADM estimated by FCM analysis was significantly increased (P < 0.05) in MKN45R even though there was no significant increase of P-glycoprotein expression. These results suggest that although ADM was still effective based on a standard drug sensitivity test, the cancer cells were already acquiring resistance to ADM as judged from FCM analysis. Moreover, the mechanism of this ADM resistance is considered to be independent of P-glycoprotein expression. Thus, FCM analysis is useful for detecting the early steps in the development of drug resistance of cancer cells.