Extraction, characterization, and anticancer potential of extracellular polymeric substances from marine actinobacteria of Streptomyces species

To check the ability of the anticancer activity, the extracted extracellular polymeric substances (EPS) from marine actinobacteria were done. Potential of the anticancer activity of EPS which was extracted from marine actinobacteria of Streptomyces species through an assay called MTT. Marine actinobacterial isolation, identification and micromorphology of the strain, and biochemical analysis were performed (Shirling and Gottlieb, 1966). The production of EPS from marine actinobacteria was quantified(P. Sivaperumal et al., 2018). Carbohydrate content in the EPS was quantified, and MCF-7 cell proliferation was done using an MTT assay. EPS-producing marine Streptomyces was isolated and identified. The production of EPS and their protein, carbohydrate, lipid, and other parameters were estimated. Further, the EPS showed more than 50% of inhibition after 72 h using the MTT assay in the MCF-7 cancer cell line. The present study exhibited that EPS from marine Streptomyces species has significant anticancer activity.

Cytotoxic Effect of Lippia nodiflora Leaf Extract against the Prostate Cancer Cell Line

Prostate cancer is the second most common cause of cancer deaths for men. Lippia. Nodiflora (L. nodiflora) has been used as a natural remedy for various diseases, because of its antioxidant, anti-inflammatory, anti-bacterial, and anti-tumor effect. This study was to investigate the cytotoxic effect of L. nodiflora ethanolic leaf extract in prostate cancer cell lines (PC-3). The growth inhibitory effect of L. nodiflora ethanolic leaf extract was assessed by MTT assay. The cell morphological changes in L. nodiflora leaf extract-treated cells were observed using an inverted phase-contrast microscope. Apoptosis induction by L. nodiflora was determined by AO/EtBr (acridine orange and ethidium bromide) dual staining. MTT test results showed dose-dependent cell growth inhibition in PC-3 cells treated with L. nodiflora leaf extract (10-120 µg/mL). The IC-50 dose was observed at 40µg/ml. Morphological changes such as reduction in the number of cells, cell shrinkage, and cytoplasmic membrane blebbing were observed in the treated cells. Induction of apoptosis by L. nodiflora (40µg/ml) treated cells showed an increased number of early apoptotic and late apoptotic cells. The above data indicate that L. nodiflora inhibits cell proliferation and induces apoptosis in prostate cancer cells. Therefore, it can be concluded that L. nodiflora exhibits anti-cancer activity, and thus it raises new hope for its use in anti-cancer therapy.

Anti-Cancer Effects of Saraca asoca Flower Extract on Prostate Cancer Cell Line

Background: Prostate cancer is the second most common cause of cancer deaths for men. The role of plants in the prevention and treatment of disease has been known from the dawn of civilization. Plants maintain the health and vitality of individuals and also cure diseases, including cancer without causing toxicity. More than 50% of all modern drugs in clinical use are of natural products, many of which have the ability to control cancer cells. Saraca Asoca (Roxb.), De. Wild or Saraca indica is one of the most ancient trees of India Aim: Aim of this study is to investigate the anti-cancer effects of Saraca Asoca flower extract on prostate cancer cell line. Materials and Methods: The anti-cancer effects of Saraca Asoca extract on prostate cancer cell lines was assessed by cell viability assay, cell and nuclear morphological studies. The multiple concentration of Saraca Asoca extract (0, 20, 40, 60, 80, 100 and 120 µg/ml) was used and IC50 doses were calculated. Results: The MTT (3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl-tetrazolium bromide) assay results showed the percentage of cell viability significantly decreased in treated cells compared to control groups without any treatment was represented as 100% and we observed inhibitory concentration was 60µg/ml. Morphologic changes observed showed cell shrinkage, and cytoplasmic membrane blebbing, were observed under phase-contrast microscope. The apoptotic nuclei (intensely stained, fragmented nuclei, and condensed chromatin) were viewed under a fluorescent microscope. Conclusion: Overall, the present study results demonstrated the cytotoxic and proapoptotic effects of Saraca Asoca flower extract on prostate cancer cell line. However, more research is needed to understand the active prinsciple compounds present in the extract and molecular mechanisms of its anti-cancer effects.

Pro-Apoptotic Effect of Lippia nodiflora Leaf Extract against the Skin Cancer Cell Line

Background: Skin cancers are cancers that develop on the surface of the skin. They occur as a result of the formation of irregular cells with the potential to infiltrate or migrate to other areas of the body. Natural medicinal resources, such as the traditional herbal remedy Lippia nodiflora, have long been used to treat dermatological disorders including skin inflammation and melanogenesis. Apoptosis serves as a promising pathway in controlling cancer. However there are minimal amounts of studies exploring its proapoptotic activity of Lippia nodiflora in skin cancer  cells. Aim: The aim of this present study was to evaluate the pro-apoptotic effect of Lippia nodiflora leaf extract against the skin cancer cell line. Materials and Methods: MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays were used to determine the cytotoxic effect of Lippia nodiflora leaf extract against skin cancer cells (B16-F10). The skin cancer cells were treated with different concentration Lippia nodiflora leaf extract for 24h. We calculated the optimum (IC-50; 20µg/ml) using the MTT assay, which was then used for further analysis. A phase-contrast microscope is used to analyse changes in cell morphology. AO/EtBr dual staining under a fluorescence microscope was used to determine the effect of Lippia nodiflora on B16-F10 cell death. Results: In our research, the cell viability of the B16-F10 skin cancer cell line was dramatically decreased after treatment with different concentrations (5-60 µg/ml) of Lippia nodiflora for 24 hours. 50% inhibition was detected at a concentration of 20 µg/ml, which was determined to be an inhibitory concentration (IC-50) value and used in subsequent studies. The viable cell will possess a uniform bright green nucleus. Early apoptotic cells will have bright orange areas of condensed or fragmented chromatin in the nucleus. Late apoptotic cells will have uniform bright red nucleus. Conclusion: The findings of this analysis revealed that Lippia nodiflora leaf extract inhibits the cell viability and indces apoptosis of skin cancer cells. Thus, Lippia nodiflora exhibits anti-cancer effects against skin cancer cells, therefore it raises new hope for anti-cancer therapy.

Cytotoxic Effect of Coriander Oleoresin against Lung Cancer Cell Line A549

Aim: The main aim of present study was to assess the cytotoxic effect of coriander oleoresin against lung cancer cell line A549. Introduction: Coriandrum sativum (Coriander), family Umbelliferae. Coriander contains mainly essential oil and has antioxidant, diuretic, anti-diabetic anticonvulsant, hypnotic sedative, anti-mutagenic, antimicrobial, anthelmintic activity. Materials and Methods: Coriander oleoresin (product number: 4010000243) was obtained from Synthite Industries Private Limited, Kerala. In the present study, lung cancer cell line A549 was treated with coriander oleoresin at different concentrations and later evaluated for its cytotoxic activity using MTT assay. Results: The cytotoxic effect of coriander oleoresin on lung cancer cell line was proved; the drug concentration increased, the percentage of cell viability decreased proving its cytotoxic effect. The coriander oleoresin has shown a dose dependent cytotoxic effect on lung cancer cell lines. As the drug concentration increased, the percentage of cell viability decreased proving its cytotoxic effect. The IC50 value was 80 μg/ml. Conclusion: In the present study, coriander oleoresin showed a good cytotoxic effect on lung cancer cell lines which may be helpful in treatment of lung cancer. However more research is needed to understand the underlying mechanisms of the cytotoxicity property of the plants.

Anticancer effect of Digera muricata Leaf Extract against Prostate Cancer Cell Lines

Background: Prostate cancer has become a major health problem globally during the last few decades. It is the second most frequently diagnosed cancer in men worldwide and the fifth most common cancer overall. Chemotherapy or other cancer treatments including androgen depletion therapy, show high toxicity and cause serious side effects in cancer patients. Thus, there have been many studies conducted to find various natural products as potential anticancer drug candidates with low toxicity and fewer side effects for the treatment and prevention of prostate cancer. The Digera muricata of the genus Digera Forssk and family Amaranthaceae Juss. is a wild edible plant. The  presence  of  phenol,  flavonoids, alkaloids,  terpenes,  sterols,  tannins,  glycosides  and  lignins is seen in Digera muricata leaf extract, which are reported to have cytotoxic activities. Aim of the Study: The aim of this study is to assess the cytotoxic effects of Digera muricata leaf extract on prostate cancer cell line. Materials and Methods: The cytotoxic potency of Digera muricata leaf extract was carried out by MTT (3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl-tetrazolium bromide) assay against the prostate cancer (PC-3) cell line. PC-3 cells were treated with different concentrations of Digera muricata leaf extract (25-150μg/ml) for 24h. Furthermore, the morphological changes were analysed using phase contrast microscopy and nuclear morphological changes examined using DAPI (4′,6-diamidino-2-phenylindole) staining under the fluorescence microscopy Results: The MTT assay showed decreased cell vitality with increased concentration of Digera muricata leaf extract. The morphological study showed that the number of cells decreased after treatment and the cells exhibited cell shrinkage and cytoplasmic membrane blebbing. The treated cells also showed condensed chromatin and nuclear fragmentation Conclusion: Within the limits of this study it can be demonstrated that the leaf extract of Digera muricata were cytotoxic and induced apoptosis to the cancer cells.

Evaluation of Cytotoxic Potential of Digera muricata Leaf Extract on Lung Cancer Cell Line

Lung cancer is the second most frequent cancer, accounting for one out of every five male cancers and one out of every nine female cancers. Treatment for lung cancer is determined by the disease's cell type, the extent to which it has spread, and the patient's overall health. It is common knowledge that tumours impart resistance to chemotherapeutic medicines or radiation in part owing to apoptotic pathway dysfunction in cancer cells. Digera muricata (D.muricata) has been used as medicinal remedies for various ailments due to its antioxidant, anti-inflammatory, anti-bacterial, anti-tumor activity. The objective of the study was to examine the cytotoxic activity of ethanolic leaf extract of D.muricata on lung cancer cell lines. The cytotoxic potency of D.muricata leaf extract was carried out by MTT assay against the lung cancer cell line (A549). Different concentrations of D.muricata ethanolic leaf extract (25-150µg/ml) were treated for 24h. Furthermore, the morphological changes were analysed using phase contrast microscopy. Pro-apoptotic and nuclear morphological changes in D. muricata ethanolic leaf extract treated cells were examined using DAPI staining. The ethanolic leaf extract of D.muricata showed the dose dependent cytotoxic potency against the A549 cell line which confirmed with greater morphological changes upon 24 hrs treatment. The MTT assay clearly showed that the D.muricata treatment has significantly reduced the cell viability when the concentration was increased for 24hrs. We observed IC-50 dose at 50 μg/ml concentration. DAPI staining clearly showed condensed chromatin and fragmented nuclei in treated lung cancer cells. All these results clearly showed that ethanolic extract of D. muricata treatment significantly inhibited the cell proliferation and induced apoptosis in lung cancer cells.

Investigation of Proapoptotic Effect of Digera muricata Leaf Extract against the Skin Cancer Cell Line (B16-F10)

Introduction: Skin cancers, such as melanoma, basal cell carcinoma, and squamous cell carcinoma, frequently begin as changes in the skin. Cancer research continues to focus on finding tumor-selective and new anticancer drugs with fewer adverse effects. Digera muricata is a medicinal herb in the Amaranthaceae family that has antibacterial, antifungal, free radical scavenging function, anti tumor, and other valuable medicinal properties. Aim: To investigate the pro-apoptotic effect of Digera muricata leaf extract against the skin cancer cell line. Materials and Methods: MTT assay was used to determine the viability of B16-F10 cells treated with different concentrations (20-200μg) of Digera muricata leaf extract. Phase contrast microscopy was used to examine the morphological changes. In addition, the mode of cell death was assessed using AO/EtBr dual staining and observed under a fluorescence microscope. Statistical analysis was performed, keeping the level of significance at p<0.05. Results: The MTT assay revealed that the ethanolic extract of Digera muricata leaf had significant cytotoxic and apoptotic potency against the B16-F10 skin cancer cell line, which was validated by significant morphological alterations under phase contrast microscope after 24 hours of treatment. AO/EtBr dual staining results clearly showed the Digera muricata leaf extract treatment induced the early apoptotic cells with bright orange areas of condensed or fragmented chromatin in the nucleus. Late apoptotic cells showing uniform bright red nucleus. Conclusion: Within the limits of the analysis, it can be inferred that the leaf extract of Digera muricata was cytotoxic and triggered cancer cell apoptosis at a concentration of 50 μg/ml within 24 hours. More research is needed to understand the cytotoxicity mechanisms of this plant extract.

Evaluation of Anticancer Effect of Lippia nodiflora Leaf Extract on Lung Cancer Cells

Background: Lung cancer, also known as bronchogenic carcinoma, is a kind of cancer that begins in the lung parenchyma or inside the bronchi. In the United States, it is one of the top causes of cancer-related fatalities. Lippia nodiflora is a flowering, broadleaf plant native to South America. Lippia nodiflora has been used as a natural medicine for a number of disorders due to its antioxidant, anti-inflammatory, anti-bacterial, and anti-tumor characteristics. Aim of the Study: To evaluate the anticancer effect of Lippia nodiflora leaf extract on lung cancer. Materials and methods: The cytotoxic effect of Lippia nodiflora leaf extract was assessed by an MTT assay. The A-549 cells were treated with different concentrations of Lippia nodiflora leaf extract (10-120 μg) for 24h. Analysis of changes in the cell morphology is examined by phase contrast microscope. For the nuclear morphological changes analysis, DAPI staining was used in lung cancer cells. The apoptotic nuclei were viewed under a fluorescent microscope. Results: In our study, Lippia nodiflora leaf extract treated cells showed significant reduction of cell viability in lung cancer cells. 50% of the inhibition was observed in a 20 μg/ml concentration, which has been taken as the inhibitory concentration (IC-50) which was used for further analyses. The pro-apoptotic effect of Lippia nodiflora leaf extract in A549 cell line was determined by DAPI staining under a fluorescence microscope. Lippia nodiflora leaf extract treatment alters the nuclear morphology and condensed nuclei in lung cancer cells at 20μg/ml concentration. Conclusion: Overall, it can be concluded that Lippia nodiflora presents anticancer activity at 20μg/ml concentration at 24 hrs againstthe lung cancer cell line. However, further research is warrented to find out the molecular mechanism of cytotoxicity of effect this plant extract against lung cancer.

Evaluation of Proapoptotic Potential of Saraca asoca Flower Extract on Skin Cancer Cell Line

Background: Cancer persists as a major health issue globally due to its high rate of morbidity and mortality. Skin cancer is the most common cancer and accounts for at least 40% of cancer cases worldwide. Search for tumour-selective and novel anticancer compounds with lesser side effects remains a major focus of cancer research. Saraca asoca is a traditional Indian medicinal plant, known to have anti-cancer, anti-menorrhagic, anti-oxidant, anti-oxytocic and anti-microbial activities. Though phytoconstituents of the Saraca asoca leaves, bark, and flowers have been reported in few studies, the cytotoxic potential of Saraca asoca flowers has not been evaluated. Aim: To evaluate the proapoptotic potential of Saraca asoca flower extract on skin cancer cell line. Materials and Methods: In this present study, the cytotoxic potential of Saraca asoca flower extract (10 to 60μg/ml) was evaluated by MTT assays in B16-F10 skin cancer cells. According to the MTT assay, we determined the optimal doses (IC-50: 30µg/ml) which were used for further analyses. Analysis of changes in cell morphology is examined by a phase-contrast microscope. The impacts of Saraca asoca in B16-F10 cell death were also determined by AO/EtBr dual staining under a fluorescence microscope. Results: In our study, the cell viability assay results showed that 50% of growth inhibition was observed at 30 μg/ml concentration of Saraca asoca flower extract treated B16-F10 cells, which has been taken as an inhibitory concentration (IC-50) dose value and fixed for further experiments. The morphological changes in B16-F10 skin cancer cell line with the treatment of Saraca asoca at 30 μg/mL for 24hrs has significantly altered  the morphology of B16-F10 cell lines. AO/EtBr dual staining results showed the early apoptotic cells having bright orange areas of condensed or fragmented chromatin in the nucleus after Saraca asoca flower extract treated skin cancer cells. Conclusion: The results of this present study showed that the flower extracts of Saraca asoca were cytotoxic and induced apoptosis to the cancer cells at a concentration of 30µg/ml at the 24th-time point.

Evaluation of Anti-Cancer Activity of Saraca asoca Flower Extract against Lung Cancer Cell Line

Lung cancer is the second most common type of cancer, affecting one out of every five men and one out of every nine women. Lung cancer treatment is dictated by the cell type of the cancer, the amount to which it has spread, and the patient's overall condition. It is well known that cancer cells, in part due to apoptotic pathway malfunction, confer resistance to chemotherapy drugs or radiation. Saraca Asoca (S. asoca) has been used as medicinal remedies for various ailments due to its antioxidant, anti-inflammatory, anti-bacterial, anti-tumor activity. The objective of the study was to evaluate the anti-cancer activity of S. asoca flower extract against lung cancer cell line. The cytotoxic effect of S. asoca flower extract was carried out by cell viability assay against the lung cell line (A549). Different concentrations of S. asoca flower ethanolic extract (20-120µg/ml) were treated for 24h. Furthermore, the morphological changes were analysed using inverted microscopy. The nuclear morphology of S. asoca flower ethanolic extract treated lung cancer was analyzed by DAPI staining. The cell viability assay clearly showed that the extract of S. asoca flower treatment has significantly reduced the lung cancer cell viability in a dose dependent manner. We observed the IC50 dose at 60 μg/ml concentration. The DAPI staining results showed increased apoptotic cells with condensed chromatin and nuclear fragmentation in ethanolic extract of S. asoca flower treatment in lung cancer cells. The present study shows ethanolic extract of S. asoca flower treatment inhibits cell growth and induces the apoptosis in lung cancer cells. Further research is needed to find out the active compounds and understand the mechanisms of anti-cancer effects of S. asoca flower.

Supercapattery and full-cell lithium-ion battery performances of a [Ni(Schiff base)]-derived Ni/NiO/nitrogen-doped carbon heterostructure

[Ni(Schiff base)]-derived Ni/NiO on the conductive carbon network is explored as an electrode material for high-performance supercapatteries and lithium-ion batteries.

Supercapacitor and photocatalytic performances of hydrothermally-derived Co3O4/CoO@carbon nanocomposite

Hydrothermally-derived Co₃O₄/CoO@carbon nanocomposite with spike-like cobalt oxide anchored on the conductive carbon network showed excellent supercapacitor and photocatalytic performances.

Gold nanoparticle-conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2-mediated pathway in breast cancer

OBJECTIVES

Epidermal growth factor plays a critical role in breast malignancies by enhancing cell proliferation, invasion, angiogenesis and metastasis. Epithelial-mesenchymal transition (EMT) is a crucial process by which epithelial cells lose polarity and acquire migratory mesenchymal properties. Gold nanoparticles are an efficient drug delivery vehicle for carrying chemotherapeutic agents to target cancer cells and quercetin is an anti-oxidative flavonoid known with potent anti-malignant cell activity.

MATERIALS AND METHODS

Cell viability was assessed by MTT assay, and protein expression was examined by Western blotting and immunocytochemistry. Cell invasion was monitored using invasion chambers, and cell migration was analysed by scratch wound-healing assay. In vitro and ex vivo angiogenesis studies were performed by capillary-like tube formation assay and chick embryo angiogenesis assay (CEA). 7,12-dimethylbenz(a)anthracene (DMBA) induced mammary carcinoma in Sprague-Dawley rats.

RESULTS

We observed a significant reduction in protein expression of vimentin, N-cadherin, Snail, Slug, Twist, MMP-2, MMP-9, p-EGFR, VEGFR-2, p-PI3K, Akt and p-GSK3β, and enhanced E-cadherin protein expression in response to AuNPs-Qu-5 treatment. AuNPs-Qu-5 inhibited migration and invasion of MCF-7 and MDA-MB-231 cells compared to free quercetin. AuNPs-Qu-5-treated HUVECs had reduced cell viability and capillary-like tube formation. In vitro and in vivo angiogenesis assays showed that AuNPs-Qu-5 suppressed tube and new blood vessel formation. Treatment with AuNPs-Qu-5 impeded tumour growth in DMBA-induced mammary carcinoma in SD rats compared to treatment with free quercetin.

CONCLUSION

Our results suggest that AuNPs-Qu-5 inhibited EMT, angiogenesis and metastasis of the breast cancer cells tested by targeting the EGFR/VEGFR-2 signalling pathway.

Predicting Ligand Binding Sites on Protein Surfaces by 3-Dimensional Probability Density Distributions of Interacting Atoms

Predicting ligand binding sites (LBSs) on protein structures, which are obtained either from experimental or computational methods, is a useful first step in functional annotation or structure-based drug design for the protein structures. In this work, the structure-based machine learning algorithm ISMBLab-LIG was developed to predict LBSs on protein surfaces with input attributes derived from the three-dimensional probability density maps of interacting atoms, which were reconstructed on the query protein surfaces and were relatively insensitive to local conformational variations of the tentative ligand binding sites. The prediction accuracy of the ISMBLab-LIG predictors is comparable to that of the best LBS predictors benchmarked on several well-established testing datasets. More importantly, the ISMBLab-LIG algorithm has substantial tolerance to the prediction uncertainties of computationally derived protein structure models. As such, the method is particularly useful for predicting LBSs not only on experimental protein structures without known LBS templates in the database but also on computationally predicted model protein structures with structural uncertainties in the tentative ligand binding sites.

Nimbolide inhibits invasion and migration, and down-regulates uPAR chemokine gene expression, in two breast cancer cell lines

OBJECTIVES

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death in women, worldwide. Urokinase type plasminogen activator (uPA) is a serine protease that is involved in cancer progression, especially invasion and metastasis of breast cancer. Nimbolide is a potent cytotoxic limnoid isolated from Azadirachta indica. Our previous studies have shown that nimbolide elicits pleiotropic effects on breast cancer cells; however, its roles in invasion and migration have not previously been fully elucidated.

MATERIALS AND METHODS

Protein expression of pEGFR, VEGFR, NFκB, IKKα, IKKβ, MMP-2, MMP-9 and TIMP-2 were analysed by western blotting. We also analysed expressions of uPA, uPAR genes and chemokines by real-time PCR. Breast cancer cell invasion was assessed by transwell invasion assay and cell migration analysed by scratch wound healing assay.

RESULTS

Our results showed that reduced protein expression of pEGFR, VEGFR, NFκB, IKKα, β, MMP-2, MMP-9 and TIMP-2 was higher in nimbolide-treated breast cancer cells. mRNA expression of uPA, uPAR, chemokines and their receptors were also significantly reduced in response to nimbolide treatment. Nimbolide inhibited breast cancer cell migration and invasion as shown in transwell invasion and wound healing assays.

CONCLUSION

These results clearly proved inhibitory effects of nimbolide on tumour cell invasion and migration by down-regulating proteins critically involved in regulation of cell invasion and metastasis, suggesting a possible therapeutic role of nimbolide for breast cancer.

Quercetin reverses EGF-induced epithelial to mesenchymal transition and invasiveness in prostate cancer (PC-3) cell line via EGFR/PI3K/Akt pathway

Epidermal growth factor (EGF) plays an important role in metastasis and tumorigenesis of prostate cancer. Epithelial-mesenchymal transition (EMT) is a process in tumor progression during which cancer cells undergo dramatic changes acquiring highly invasive properties. The purpose of this study was to determine the effect of quercetin on EGF-induced EMT in prostate cancer (PC-3) cell line. Quercetin, a plant flavonoid, prevented EGF-induced invasion and migration of PC-3 cells. The protein and mRNA expressions of E-cadherin and N-cadherin were studied by immunocytochemistry, Western blotting and real-time polymerase chain reaction. Quercetin prevented EGF-induced expression of N-cadherin and vimentin and increased the expression of E-cadherin in PC-3 cells, therefore preventing EGF-induced EMT. EGF-induced cell adhesion proteins, intercellular adhesion molecule and vascular cell adhesion molecule were significantly decreased by quercetin treatment. Furthermore, mRNA and protein expressions of Snail, Slug and Twist showed that quercetin significantly decreased EGF-induced expressions of Snail, Slug and Twist. The protein expressions of epidermal growth factor receptor (EGFR)/phosphatidylinositide 3-kinases (PI3K)/Akt/extracellular signal-regulated kinase (ERK)1/2 pathway showed that quercetin prevents EGF-induced EMT via EGFR/PI3k/Akt/ERK1/2 pathway and by suppressing transcriptional repressors Snail, Slug and Twist in PC-3 cells. Thus, it is concluded from the present study that quercetin may prevent cancer metastasis by targeting EMT.

Anti-cancer activity of quercetin in neuroblastoma: an in vitro approach

Neuroblastoma is a neuroendocrine tumour derived from neural crest cells and it remains a major therapeutic challenge in pediatric oncology. As response rates to chemotherapy are low, surgery remains the only effective treatment but since many tumors have metastasized at the time of diagnosis, curative surgery is rarely achieved. Consequently, a substantial need for new therapeutic options emerges. Quercetin a flavonoid, has been reported to lower the risk of several cancers. This study was designed to investigate its effects on apoptosis induction in the N2a, a mouse neuroblastoma cell line. The cell viability was determined by dimethyl thiazolyl tetrazolium bromide assay and diamidino-2-phenylindole staining was performed to confirm the apoptosis. The gene expression of bcl-w, p53, p27 and protein expression of caspases (3 and 9), bax, cytochrome-c were studied. This in vitro outcome suggests that quercetin can be used as a potent anti-cancer drug in future.

Molecular modeling to investigate the binding of Congo red toward GNNQQNY protofibril and in silico virtual screening for the identification of new aggregation inhibitors

Understanding the nature of the recognition between amyloid protofibrils and dye molecules at the molecular level is essential to improving instructive guides for designing novel molecular probes or new inhibitors. However, the atomic details of the binding between dyes and amyloid fibrils are still not fully understood. In this study, molecular docking, consensus scoring, molecular dynamics (MD), and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) analyses were integrated to investigate the binding between Congo red (CR) and the GNNQQNY protofibril from yeast prion protein Sup35 and to further evaluate their binding stabilities and affinities. Our results reveal that there are four CR binding sites located on GNNQQNY protofibril surface. These four CR binding sites adopt dual binding modes by which CR binding with its long axis parallel and perpendicular to the long axis of the protofibril. In addition, CR was also found to bind to the edge of the protofibril via hydrophobic/aromatic and hydrogen-bonding interactions, which is inferred as the possible inhibition mechanism to prevent the elongation of the protofibril from the addition of incoming peptides. Virtual screening from National Cancer Institute (NCI) database obtained three hit compounds with higher binding affinity than CR to the edge of the protofibril due to the fact that the central parts of these compounds are able to form additional hydrogen bonds with the protofibril. The results of the study could be useful for the development of new molecular probes or inhibitors for clinical applications.

Effect of diallyl disulfide on insulin-like growth factor signaling molecules involved in cell survival and proliferation of human prostate cancer cells in vitro and in silico approach through docking analysis

PURPOSE

Diallyl Disulfide (DADS) is one of the major components of garlic, which inhibits the proliferation of various cancer cells. Our previous studies showed that DADS inhibits cell growth and induces apoptosis on prostate cancer cells. Insulin like growth factor signaling pathway plays a significant role on prostate cancer cell growth and survival and it's over expression also identified in human prostate cancers. The molecular mechanism of IGF mediated PI3K/Akt signaling remains to be elucidated. The present study was designed to evaluate the effects of diallyl disulfide on IGF signaling in androgen independent prostate cancer cells (PC-3).

METHODS

DADS (10-50 μM) caused dose-dependent inhibition of PC-3 cells, were analyzed by MTT, IC50 value of PC-3 cells was 40 μM for 24h. Interestingly, DADS also altered the mRNA and protein expressions of IGF signaling and apoptotic molecules which were confirmed by semi quantitative PCR and western blot method. Further the docking study of DADS with IGF receptor was carried out by Ligand Fit of Discovery studio. Accord Excel Package was used for the prediction of ADME properties of the compound.

RESULTS

The results suggests that DADS decreases the survival rate of androgen independent prostate cancer cells by modulating the expression of IGF system, which leads to inhibition of phosphorylation of Akt, thereby inhibits cell cycle progression and survival by lowering the expression of cyclin D1, NFkB and anti-apoptotic Bcl-2 molecule and increasing the level of pro-apoptotic (Bad and Bax) signaling molecules which leads to apoptosis.

CONCLUSION

The present investigation showed downregulation of Akt and a concomitant increase in apoptosis in DADS treated prostate cancer cells. Since inhibition of this Akt pathway by DADS leads to inhibition in cancer cell progression, it is highly suggested that DADS has the potential use as a therapy for prostate cancer.

Homology modeling and dynamics study of aureusidin synthase--an important enzyme in aurone biosynthesis of snapdragon flower

Aurones, a class of plant flavonoids, provide bright yellow color on some important ornamental flowers, such as cosmos, coreopsis, and snapdragon (Antirrhinum majus). Recently, it has been elucidated that aureusidin synthase (AUS), a homolog of plant polyphenol oxidase (PPO), plays a key role in the yellow coloration of snapdragon flowers. In addition, it has been shown that AUS is a chalcone-specific PPO specialized for aurone biosynthesis. AUS gene has been successfully demonstrated as an attractive tool to engineer yellow flowers in blue flowers. Despite these biological studies, the structural basis for the specificity of substrate interactions of AUS remains elusive. In this study, we performed homology modeling of AUS using Grenache PPO and Sweet potato catechol oxidase (CO). An AUS-inhibitor was then developed from the initial homology model based on the CO and subsequently validated. We performed a thorough study between AUS and PTU inhibitor by means of interaction energy, which indicated the most important residues in the active site that are highly conserved. Analysis of the molecular dynamics simulations of the apo enzyme and ligand-bound complex showed that complex is relatively stable than apo and the active sites of both systems are flexible. The results from this study provide very helpful information to understand the structure-function relationships of AUS.

Investigation of cation-π interactions in sugar-binding proteins

Cation-π interaction is a non-covalent binding force that plays a significant role in protein stability and drug-receptor interactions. In this work, we have investigated the structural role of cation-π interactions in sugar-binding proteins (SBPs). We observed 212 cation-π interactions in 53 proteins out of 59 SBPs in dataset. There is an average one energetically significant cation-π interaction for every 66 residues in SBPs. In addition, Arg is highly preferred to form cation-π interactions, and the average energy of Arg-Trp is high among six pairs. Long-range interactions are predominant in the analyzed cation-π interactions. Comparatively, all interaction pairs favor to accommodate in strand conformations. The analysis of solvent accessible area indicates that most of the aromatic residues are found on buried or partially buried whereas cationic residues were found mostly on the exposed regions of protein. The cation-π interactions forming residues were found that around 43% of cation-π residues had highly conserved with the conservation score ≥6. Almost cationic and π-residues equally share in the stabilization center. Sugar-binding site analysis in available complexes showed that the frequency of Trp and Arg is high, suggesting the potential role of these two residues in the interactions between proteins and sugar molecules. Our observations in this study could help to further understand the structural stability of SBPs.