Anticancer drug screening of natural products:In vitro cytotoxicity assays,techniques,and challenges

Natural products include several diverse compounds that have been found to be effective against cancer.Discovering anticancer compounds in nature is a multistep and complex process that requires pre-clinical and clinical studies.Only a few of the available natural products are used to treat cancer since most of them have very high complexity and low bioavailability.Therefore,the process of anticancer drug discovery requires a straightforward and effective method to assess anticancer activity using in vitro assays.This review summarizes various cell-based assays and techniques used to measure cell viability,migration,and apoptosis,focusing in particular on the principles,mechanisms,advantages,and disadvantages of each assay to provide a preliminary platform for cancer drug discovery.

Rabbit Defensin(NP-1) Gene Transformation of Wheat and In Vitro Microbicidal Activity Assay of Transgenic Plants

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Assessment of in vitro sensitivity of Plasmodium vivax fresh isolates

Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210.Methods:The study was conducted at Mae Tao Clinic for migrant workers,Tak Province during April 2009 to July 2010.A total of 64 blood samples(1 mL blood collected into sodium heparinized plastic tube) were collected from patients with monoinfection with P.vivax malaria prior to treatment with standard regimen of a 3-day chloroquine. In vitro sensitivity of P.vivax isolates was evaluated by schizont maturation inhibition and SYBR Green-Ⅰ assays.Results:A total of 30 out of 64 blood samples collected from patients with P.vivax malaria were successfully analyzed using both the microscopic schizont maturation inhibition and SYBR Green-I assays.The failure rates of the schizont maturation inhibition assay(50%) and the SYBR Green-I assay(54%) were similar(P=0.51).The median IC_(10)s,IC_(50)s and IC_(90)s of both chloroquine and WR99210 were not significantly different from the clinical isolates of P.vivax tested.Based on the cut-off of 100 nM,the prevalences of chloroquine resistance determined by schizont maturation inhibition and SYBR Green-I assays were 19 and 11 isolates,respectively.The strength of agreement between the two methods was very poor for both chloroquine and WR992I0.Conclusions:On the basis of this condition and its superior sensitivity,the microscopic method appears better than the SYUK Green-I Green assay for assessing in vitro sensitivity of fresh P.vivax isolates to antimalarial drugs.

Anti-melanoma action of small molecular peptides derived from Brucea javanica(L.)Merr.globulin in vitro

Objective:The morbidity of malignant melanoma keeps increasing annually.It has high risks of metastasis,drug resistance,and poor prognosis in clinics.Moreover,the available medicines used commonly,such as dacarbazine,temozolomide,the v-Raf murine sarcoma viral oncogene homolog B1(BRAF)inhibitor vemurafenib,and the programmed cell death protein 1 inhibitor pembrolizumab,have some limitations at some extent.Therefore,a more effective therapeutic strategy is still urgently necessary.Methods:In this study,Brucea javanica(L.)Merr.globulins were hydrolyzed with pepsin,then ultra-filtrated to collect small molecular peptides(≤3 kDa).The peptides were then analyzed by antiproliferative assay,cell-cycle distribution,apoptosis assay,and in vitro wound-scratch assay.Finally,western blotting was conducted to elucidate the underlying anti-melanoma mechanism.Results:The small molecular peptide from B.javanica significantly inhibited malignant melanoma cell proliferation with the IC_(50) of 2.72 mg/mL for 72 h.Further analysis indicated that B.javanica peptides arrested cell cycle at the S and G2/M phases and induced apoptosis by upregulating p21,p53,Bax,caspase-3,and cleaved PARP while downregulating Bcl-2 expression.The inhibitory migration effects were also confirmed by wound-healing assay.Conclusion:The small molecular biopeptides from B.javanica may be a promising bioactive agent candidate for melanoma treatment.

Antifilarial activity of ethyl acetate extract of Vitex negundo leaves in vitro

Objective:To evaluate the possible antifilarial effect of ethyl acetate extract of Vitex negundo(Verhenaceae)leaves against Selaria cervi filarial parasite in vitro.Methods:In vitro screening was done by the method of motility inhibition and NTT reduction assay with concentralions of0.03 to 1.00 mg/mL for 2 to 24 h incubation periods respectively,for possible antifilarial effect by comparing with control.Results:In motility assay,complete inhibition of motility was observed and in MTT reduction assay which gave>50%reduction for concentrations 0.20,0.50and 1.00 mg/mL at 10,6 and 2 h incubation periods respectively in a dose dependent manner(P<0.05).An antifilarial effect imparted by plant extract was found to be a function of their relative concentrations.Inhibitory concentration(IC_(50))for the plant extract was found to be 0.16mg/mL.Conclusions:The present study recorded significant antifilarial effect of Vitex negundo plant extract and contributed toward the development of database for novel drug candidates for lymphatic fllariasis.

Cell Survival Assays for Individualised Chemotherapy in Primary Glioma Cultures—Colourmetric or Luminescent?

In vitro chemosensitivity testing of short term primary glioma cultures derived from brain biopsies is still in the research phase and has not yet found a place in clinical use. The main reasons for this slow progression are the small amounts of tissue available and the lack of a suitably sensitive assay capable of use in the clinical setting. This study examines whether the MTS and ATP cell survival assays, which determine cytotoxicity via colorimetric and luminescence analysis respectively, could potentially fulfill this role. Primary glioma cultures were tested for chemosensitivity using the MTS and ATP assays and were found to be generally sensitive to cisplatin and paclitaxel but relatively resistant to carmustine and etoposide. For both assays, LD50 values lay in the range 2 - 130 μg/ml but in the vast majority of cases, those obtained by the ATP assay were markedly lower those obtained by the MTS assay. Moreover, at cell numbers less than 2000 in the cases of paclitaxel and carmustine and less than 4500 in the case of cisplatin, these drugs were generally indicated as ineffective against the glioma cultures tested by the MTS assay but effective against these cultures by the ATP assay. These data clearly demonstrate that the ATP assay is more sensitive when estimating small cell numbers generated by primary glioma cultures from brain biopsies and more reliably detects higher kill rates by anticancer drugs. This study also supports the feasibility of using the ATP assay for chemosensitivity testing in a clinical setting.

Comparative Analysis of Pathogenicity Assays and PCR for <i>Listeria monocytogenes</i>Isolated from Animal, Raw Food and Environmental Sources in Korea

Results of PCR with oligonucleotide primers were designed from the assembled panel of four potential virulence genes (two of internalin gene and two of transcriptional regulator gene). Most of the isolates including reference strains were reactive by PCR, whereas the other strains (No.80, 81, and 83) isolated from pork, were non-reactive by PCR. In particular, all pork isolates were PCR-negative for two primers (lmo2672 and 2821) sets tested. However, No.82 was positive for lmo1134 primer, and No.84 was positive for lmo2470 of pork isolates. It was observed that all Listeria monocytogenes (L. monocytogenes) penetrate Vero cells, although the invasion efficiency of each strain varied (between 0.5 and 18.9%). When compared in cell assay with PFGE, the results were shown that the mean invasion efficiency for lineage II isolate (2.6%) was significantly lower (ANOVA-test,

Anti-Inflammatory Efficacy of Product Containing “Skin Calm Complex” <i>in Vitro</i>Reconstructed Epidermis

Atopic dermatitis is classified as a chronic inflammatory skin disease, which is characterized by alterations in barrier function and immune system of the skin. In a previous study, the efficacy of REPAVAR ATOPIC SKIN BODY CREAM EXTREME (a product containing “SKIN CALM COMPLEX”) on the epidermal barrier structure was demonstrated. However, the product has also been formulated to improve inflammation and itching. The aim of this study is to analyze product effectiveness on skin inflammation and itching which is associated with atopic dermatitis, by quantification of IL-1α and IL-8 interleukins secreted by human keratinocytes from reconstructed epidermis by ELISA assay. Mature (aged 17 days) sample tissues were treated with pro-inflammatory agents (PBS 1X and LPS) and with the product containing synergistic mix from plants extracts and Dihydroavenanthramide D, among other ingredients (“SKIN CALM COMPLEX”) for 24 hours. Measuring the amounts of interleukins by ELISA assay showed 1) decreased levels of IL-1α and 2) no differences about IL-8 secretion. Product REPAVAR ATOPIC SKIN BODY CREAM EXTREME has an anti-inflammatory effect on the release of pro-inflammatory cytokines, becoming an effective preventive agent on inflammation and itching due to maintenance and improvement of the keratinocyte epidermal structure.

Network pharmacology and preliminary cell screening studies on the anti-liver cancer activity of Nauclea Officinalis

Objective:To explore the mechanism of Nauclea Officinalis of anti-liver cancer effect based on network pharmacology,and to preliminarily verify anti-liver cancer activity of Nauclea Officinalis through cell screening.Methods:Network pharmacology was used to screen for common targets of Nauclea Officinalis and liver cancer,protein-protein interaction(PPI)network was constructed,and enrichment analysis and mechanism prediction were conductd.Molecular docking of main active ingredients of Nauclea Officinalis with core targets was made.Preliminary verification was performed by in vitro cell experiments such as CCK8,cell apoptosis,and PCR.Results:After the screening,14 active ingredients of Nauclea Officinalis were obtained,with 587 related targets.After mapping with liver cancer targets,there were 288 common targets,mainly including TP53,SRC,STAT3,and other core targets.Among them,compounds such as strictosamide,pumiloside and vincosamide may be potential active ingredients of Nauclea Officinalis of anti-liver cancer effect.They may participate in protein phosphorylation and negative regulation of the apoptosis process by mediating cancer pathways,PI3K/Akt and EGFR tyrosine kinase inhibitors resistance signaling pathways to play an anti-liver cancer role;molecular docking results showd that active ingredients of Nauclea Officinalis had a stable binding with liver cancer core targets;in vitro cell experiments showd that main ingredient strictosamide of Nauclea Officinalis had cytotoxicity against liver cancer cells,inhibited liver cancer cell proliferation(P<0.001),down-regulated gene expression of liver cancer HepG2 cells SRC,STAT3,MAPK3(P<0.05),and induced liver cancer cell apoptosis(P<0.001).Conclusion:This study preliminarily explores the potential mechanism of active ingredients of Nauclea Officinalis against liver cancer and its preliminary pharmacological effects,providing a theoretical basis for the study of Nauclea Officinalis of anti-liver cancer mechanism.

Pedalium murex Linn(Pedaliaceae) fruits:a comparative antioxidant activity of its different fractions

Objective:To examine the antioxidant activity and total phenolic content of different solvent fractions of Pedulium murex(P.murex)Linn fruits(Family:Pedaliaceae)as well as the correlation between the total antioxidant capacity and total phenolic content.Methods:In the present study,the antioxidant activities of P.murex were evaluated using six in-vitro assays,namely total antioxidant assay,DPPH assay,reducing power,nitric oxide scavenging,hydrogen peroxide scavenging and deoxyribose scavenging assays,and total phenol contents were also investigated.Results:The ethyl acetate(EA)fraction was found to have high levels of phenolic content(298.72±2.09 mg GAE/g).The EA fraction exhibit higher total antioxidant capacity,higher percentage of DPPH radical scavenging activity(135.11±2.95μg/mL),nitric oxide(200.57±4.5lμg/mL),hydrogen peroxide(2I7.91±6.12μg/mL),deoxyribose(250.01±4.68μg/mL)and higher reducing power.Correlation coefficient(r^2=0.914)was found to be significant between total phenolic content and total antioxidant activity.Conclusions:In general,the results indicate that the EA fractions are rich in phenolic antioxidants with potent free radical scavenging activity implying their importance to human health.

Comparison of Different MARs(Matrix Attachment Regions) Effect on Transgene Expression

Three MARs(matrix attachment regions)fragments were cloned from tobacco(Nicotiana tabacum)(MAR1), yeast(Saccharomyces cerevisiae)(MAR3)and kidney bean(Phaseolus vulgaris)(MAR5)which ranged 984, 822 and 782bp, respectively. Sequence analysis showed that all thefragments had fairly high A/T content (73, 62 and 75%, respectively),harbored differentnumber and different type of some characteristic motifs of MARs, such as A-box and T-box,etc. The results of in vitro binding assay showed that the three MARs fragments derivedfrom different organisms could bind specifically to the matrix extracted from the tobacconuclei with different strength, which also demonstrated that these MARs fragments arefunctionally conserved during evolution. By using these MARs fragments to flank the β-glucuronidase (GUS) reporter gene and bialaphos resistance(bar) selectable marker gene,and then introducing the resulting plant expression vectors containing MARs-uidA-bar-MARs into tobacco through Agrobacterium mediated procedures, the effects of MARs sequenceson the expression of transgenes in tobacco were investigated and compared. The GUSactivity in individual transformants showed that, comparing to the controls withoutadditional MARs, the overall transgene expression level in transformants with MARs hadbeen greatly increased while the variations in transgene expression among transformantswere decreased in different degrees. In accordance with the results of sequence analysisand in vitro binding assay in which MAR1 fragment showed the strongest binding strength,this MARs fragment also showed the greatest effect in increasing transgene overallexpression level.

How old is too old? In vivo engraftment of human peripheral blood stem cells cryopreserved for up to 18 years-implications for clinical transplantation and stability programs

BACKGROUND Peripheral blood stem cells(PBSC)are commonly cryopreserved awaiting clinical use for hematopoietic stem cell transplant.Long term cryopreservation is commonly defined as five years or longer,and limited data exists regarding how long PBSC can be cryopreserved and retain the ability to successfully engraft.Clinical programs,stem cell banks,and regulatory and accrediting agencies interested in product stability would benefit from such data.Thus,we assessed recovery and colony forming ability of PBSC following long-term cryopreservation as well as their ability to engraft in NOD/SCID/IL-2 Rγnull(NSG)mice.AIM To investigate the in vivo engraftment potential of long-term cryopreserved PBSC units.METHODS PBSC units which were collected and frozen using validated clinical protocols were obtained for research use from the Cellular Therapy Laboratory at Indiana University Health.These units were thawed in the Cellular Therapy Laboratory using clinical standards of practice,and the pre-freeze and post-thaw characteristics of the units were compared.Progenitor function was assessed using standard colony-forming assays.CD34-selected cells were transplanted into immunodeficient mice to assess stem cell function.RESULTS Ten PBSC units with mean of 17 years in cryopreservation(range 13.6-18.3 years)demonstrated a mean total cell recovery of 88%±12%(range 68%-110%)and post-thaw viability of 69%±17%(range 34%-86%).BFU-E growth was shown in 9 of 10 units and CFU-GM growth in 7 of 10 units post-thaw.Immunodeficient mice were transplanted with CD34-selected cells from four randomly chosen PBSC units.All mice demonstrated long-term engraftment at 12 wk with mean34%±24%human CD45+cells,and differentiation with presence of human CD19+,CD3+and CD33+cells.Harvested bone marrow from all mice demonstrated growth of erythroid and myeloid colonies.CONCLUSION We demonstrated engraftment of clinically-collected and thawed PBSC following cryopreservation up to 18 years in NSG mice,signifying likely successful clinical transplantation of PBSC following long-term cryopreservation.

Cytotoxicity Tests for Evaluating Medical Devices: An Alert for the Development of Biotechnology Health Products

The risks and damages related to the use of products, technologies and services of sanitary interest can be due to defects or manufacturing failures. Certain products already contain a certain degree of risk, which requires strict quality control in their production, distribution and use, as well as in the disposal of their waste in the environment. With continuous development in science and technology, medical devices must undergo intradermal irritation and testing for sensitization, cytotoxicity, and acute systemic toxicity. In health care, biotechnology aims to provide technology-based products or processes related to energy, food, and health, which are capable of stimulating new businesses, expanding exports, integrating the value chain and stimulating new demands for innovative products and processes, taking into account health policies. The present article was prepared by a bibliographical survey of the electronic databases PubMed, Lilacs, and Bireme. Cell culture testing can be successfully employed, as it is reproducible, rapid, sensitive, and financially accessible for performing in vitro toxicity testing. Thus, it has been possible to optimize the development phase of new products by decreasing animal use or even replacing them in certain tests. Some in vitro assays validated by the Organization for Economic Cooperation and Development in the area of health products have already replaced animal testing.

MEDICINAL PLANTS OF THE GENUS LEONURUS AND SEVENTEEN OF THEIR ISOLATED CONSTITUENTS SCREENED FOR EFFECTS ON PPARa,β/δ, and γ IN AN IN VITRO LUCIFERASE REPORTER GENE ASSAY

Leonurus japonicus Houtt.is used in TCM to treat the metabolic syndrome.However,up to now,no active constituents could be identified.Here we describe the isolation of 17 dominant constituents of L.japonicus and the related European herb Leonurus cardiaca L.-namely7R-chloro-6-desoxy-harpagide,ajugol,campneoside II,chicoric acid,ferulic acid,harpagide,isoacteoside,

Trends in feed evaluation for poultry with emphasis on in vitro techniques

Accurate knowledge of the actual nutritional value of individual feed ingredients and complete diets is critical for efficient and sustainable animal production.For this reason,feed evaluation has always been in the forefront of nutritional research.Feed evaluation for poultry involves several approaches that include chemical analysis,table values,prediction equations,near-infrared reflectance spectroscopy,in vivo data and in vitro digestion techniques.Among these,the use of animals(in vivo)is the most valuable to gain information on nutrient utilization and is more predictive of bird performance.However,in vivo methods are expensive,laborious and time-consuming.It is therefore important to establish in vitro methods that are reliable,rapid and practical to assess the nutritional quality of feed ingredients or complete diets.Accuracy of the technique is crucial,as poor prediction will have a negative impact on bird performance and,increase feed cost and environmental issues.In this review,the relevance and importance of feed evaluation in poultry nutrition will be highlighted and the various approaches to evaluate the feed value of feed ingredients or complete diets will be discussed.Trends in and practical limitations encountered in feed evaluation science,with emphasis on in vitro digestion techniques,will be discussed.

Isolation of a strong matrix attachment region (MAR) and identification of its function in vitro and in vivo

Inclusion of MARs in transgene cassettes enhances their expression and reduces position-effect variations in the transgenic host. Four new MARs (TM2, TM3, AM1 and AM2) were isolated from tobacco and Arabidopsis by PCR method. The nuclei isolated from suspension-cultured cells of rice were used to prepare nuclear matrix. With a characterized MAR (TM1) as a positive control, the Matrix-MAR interactions were tested by an in vitro binding assay to identify the DNA sequences as MARs and their binding strength to nuclear matrix in vitro was compared. The results showed that TM2 and TM3 had stronger binding strength than TM1. To determine the functions of the four new MARs in vivo, binary vectors pBI121 carrying a uidA GUS reporter gene were modified with direct repeat MARs inserted on both sides of the reporter gene cassette and were transferred into tobaccos via Agrobacterium-mediated transformation procedure. Quantitative GUS assays of the transgenic tobaccos showed that when flanking a GUS reporter gene

In vitro agonistic and antagonistic endocrine disrupting effects of organic extracts from waste water of different treatment processes

Effluents from wastewater treatment plant （WWTP） have been reported to have a broad spectrum of endocrine disrupting compounds （EDCs）. The majority of studies have focused on the occurrence of estrogenic activity, while ignoring nuclear hormone receptors （NRs） pathways. In the present study, a battery of in vitro yeast bioassays and a cell bioassay, including antagonistic and agonistic effects on estrogen receptor （ER）, androgen receptor （AR）, progesterone receptor （PR）, estrogen- related receptor （ERR） and aryl hydrocarbon receptor （AHR）, were conducted to evaluate the removal efficien- cies of EDCs by different treatment processes of a WWTP located in Beijing. Estrogenic, anti-estrogenic, anti- androgenic, anti-progesteronic, anti-ERR and the activa- tion of AHR activities were detected in samples from all treatment processes and the receiving water. The concen- tration of estrogenic contaminants with estradiol （E2） equivalent concentrations ranged from 0.82 x 10-9 to 3.54 x 10 9g Ee_EQ.L-1. The concentration of anti-estrogenic contaminants with 4-hydroxytamoxifen （4-OHT） equiva- lent concentrations ranged from 1.24 × 10-6 to 2.36 x 10-6 g 4-OHT-EQ.L-1. The concentration of anti-androgenic contaminants ranged from 2.21 x 10-s to 3.52 × 10-6g flutamide-EQ. L-1. The concentration of anti-progesteronic contaminants ranged from 3.15 x 10^-5 to 2.71 x 10^-4g RU486-EQ. L-1. The concentration of anti-ERR contami- nants ranged from 7.09 x 10-5 to 6.50 x 104 g 4-OHT-EQ × L^-10. The concentration of AHR activators ranged from 1.7 × 10-10 to 3.4 × 10^-10g TCDD-EQ-L-1. These processes including secondary clarifier, coagulation, as well as coal and sand filtration could eliminated 67.2% of estrogenic contaminants, 47.0% of anti-estrogenic contaminants, 98.3% of anti-androgenic contaminants, 88.4% of anti- progesteronic contaminants, 65.4% of anti-ERR contami- nants and 46.9% of AHR activators. WWTP effluents contain multiple receptor disruptors may have very complex adverse effects on exposed organisms.

Current technologies to identify protein kinase substrates in high throughput

Since the discovery of protein phosphorylation as an important modulator of many cellular processes, the involvement of protein kinases in diseases, such as cancer, diabetes, cardiovascular diseases, and central nervous system pathologies, has been extensively documented. Our understanding of many disease pathologies at the molecular level, therefore, requires the comprehensive identification of substrates targeted by protein kinases. In this review, we focus on recent techniques for kinase substrate identification in high throughput, in particular on genetic and proteomic approaches. Each method with its inherent advantages and limitations is discussed.