Behavioural Bioassays and Identification of Cashew Leaf and Stem Volatiles Mediating Attraction to the Stem Girdler, Analeptes trifasciata (Coleoptera: Cerambycidae)

The cashew stem girdler, Analeptes trifasciata Fabricius (Coleoptera: Cerambycidae), damages cashew by its girdling activities in the stem thereby causing huge economic losses. The stem girdler is managed through cultural practice of burning girdled stems and beetles, though this has drawbacks. The objective of this study was to explore the cues mediating attraction to the cashew host plant;hence the role of olfaction in host plant location by A. trifasciata underlying the semio-chemical option for controlling this insect pest. A diffusional Y-tube olfactometer was used to study the behavioural response of A. trifasciata, to freshly cut cashew stem and leaves odour sources. Methanol-extract of these plant tissues was subjected to the coupled gas chromatography-mass spectrometry (GC-MS) analysis. Y-tube olfactometric assays demonstrated that both sexes oriented towards and spent significantly more time in stem odour arm compared to the leaf odour arm in both male (male: t = 2.228, d.f = 11, P = 0.040) and female (t = 2.341, d.f = 11, P = 0.040). A combination of fatty acids, amino acids and carbohydrates were detected in cashew stems. Some of these fatty acids are attractants to other insect pests. It is suspected that these fatty acid blends may possibly be responsible for facilitating host plant location by both sexes. In conclusion, both sexes were independently and strongly attracted to the stem volatiles;this study opens the possibility of utilizing cashew stem volatiles as surveillance and control tools.

<i>N</i>-Acetylated Gemini Surfactants: Synthesis, Surface-Active Properties, Antifungal Activity, and Ecotoxicity Bioassays

A series of N-acetylated cationic gemini surfactants (3a-e) having dimeric structures derived from tertiary amines were synthesized. Their antifungal potency and surface properties were determined. It also studied the acute toxicity of the molecule with the best performance and the best water solubility (3e) through Chlorella vulgaris and Daphnia magna bioassays. The results were compared to those obtained for a commercially available reference compound 2-(thiocyanomethylthio) benzothiazole (TCMTB). Parameters such as surface tension (&#978CMC), critical micelle concentration (CMC), surface excess concentration (Γ), and area per molecule (A) were determined. The resulting values indicated that the five gemini surfactants are characterized by good surface-active and self-aggregation properties. All surfactants were tested to evaluate their antifungal activity. Six fungal strains were used to conduct the study. The minimum inhibitory concentration (MIC) value was measured by the fungal growth inhibition. The results of the MICs were compared with two commercially available reference compounds (Fluconazole and TCMTB). The least active molecule was 3e, but 3b and 3d were found to be the most potent compounds with a similar activity for all strains. Candida albicans was the most sensitive one. In contrast, Aspergillus niger was resistant. Ecotoxicity of gemini 3e was assessed: the commercial formulation (TCMTB) was between three and four orders of magnitude more toxic than the gemini one for the biological species tested.

Improvement of Teaching Experimental Design of Pesticide Bioassays

For mistakes taken in pesticide bioassays, teaching experimental design is improved in the paper, so as to let students explore and analyze in teaching experiments to get a deeper understanding of theoretical knowledge, thereby effectively avoiding frequently-taken mistakes in pesticide bioassays.

Comparison between Two Bioassays in Monitoring and Evaluation of Water Quality

[ Objective] The aim was to compare the application of two bioassays to monitoring and evaluation of water quality. [ Method ] By using two bioassays （micronucleus detecting technology based on Vicia faba root tip cells and the bioassay by luminous bacteria）, we monitored and evaluated seven kinds of single solutions respectively added different pollutants （ Hg, Cd, As, Cr6 ＋ , Pb, I_A8 and CODc,） and a mixed solution added those seven pollutants. Afterwards, we compared their results under the same pollutant and concentration, so as to study the two bioassays＇ sensitivity and sensitive concentration to the seven pollutants. [ Result] Under the same pollutant and concentration, micronucleus detecting tech- nology based on Vicia faba root tip cells had responses to Hg, Cd, As and Cr6＋ , but there was no response to Pb, LAS and CODer. However, the bioassay by luminous bacteria had responses to most pollutants except Cr6＋. Comparing the sensitive degree and concentration to each pollutant, they can complement each other. For these seven pollutants, the bioassay by luminous bacteria was better than micronucleus detecting technology based on Vicia faba root tip cells. Meanwhile, from the testing result of the mixed solution, the combined toxicity of several pollutants in lower con- cantrations was serious. At the same time, contrasted to normal chemical methods, bioassays were fast and effective. [ Conclusion] The research could provide theoretical references for the correlation study of bioassays.

Evidence from In Situ Bioassays and Suspect Analysis Revealed the Region-Specific Aquatic Risk across Socioeconomic Gradients in China

Various contaminants are present in aquatic environment and pose potential threats to pelagic and benthic organisms,calling for effective risk assessment.Traditional risk assessments based on target analysis are useful when the principal contaminants responsible for ecological risk are known;however,these approaches become challenging when dealing with chemical mixtures.In addition,the compositions of chemical mixtures often differ in regions with different levels of socioeconomic develop-ment,requiring risk assessment methods that are applicable under different pollution scenarios.Herein,in situ bioassays were conducted with two native species,Chinese rare minnows(Gobiocypris rarus)and Asian clams(Corbicula fluminea),in economically developed watersheds in China(Pearl River Basin(PRB)and Taihu Lake Basin(THB))and agriculture-dominated Poyang Lake Basin(PYB).Significant lethal and sublethal effects(e.g.,neurotoxicity,reproductive toxicity,and metabolic and oxidative stress)were observed in fish and clams irrespective of economic gradients.Notably,ecological effects differed significantly between water and sediment phases within the same region.Target(98 contaminants)and suspect screening(942 contaminants)revealed regional-specific characteristics.Ecological risk assessments using a weight of evidence approach demonstrated that both water and sediment in the PRB were at moderate to high risk,as was the sediment in the less developed PYB.However,the characteristics of mixture pollution varied greatly among regions.Suspect screening identified many pollutants that are not regularly monitored but are present at high environmental concentrations and are linked to local industrial production.These distinct mixture risk characteristics across different basins suggest that mitigating aquatic pollution requires region-specific management measures.

Barley chitinase genes expression revamp resistance against whitefly (Bemisia Tabaci) in transgenic cotton (Gossypium hirsutum L.)

Background Chitinase is an enzyme that hydrolyzes chitin,a major component of the exoskeleton of insects,including plant pests like whiteflies.The present study aimed to investigate the expression of chemically synthesized barley ch1 and chi2 genes in cotton(Gossypium hirsutum)through Agrobacterium-mediated transformation.Fifty-five putative transgenic cotton plants were obtained,out of which fifteen plants successfully survived and were shifted to the field.Using gene-specific primers,amplification of 447 bp and 401 bp fragments confirmed the presence of the ch1 and chi2 genes in five transgenic cotton plants of the T0 generation.These five plants were further evalu-ated for their mRNA expression levels.The T0 transgenic cotton plants with the highest mRNA expression level and better yield performance in field,were selected to raise their subsequent progenies.Results The T1 cotton plants showed the highest mRNA expression levels of 3.5-fold in P10(2)for the ch1 gene and 3.7-fold in P2(1)for the chi2 gene.Fluorescent in situ hybridization(FISH)confirmed a single copy number of ch1 and chi2(hemizygous)on chromosome no.6.Furthermore,the efficacy of transgenes on whitefly was evaluated through an insect bioassay,where after 96 h of infestation,mortality rates of whitefly were calculated to be 78%–80%in transgenic cotton plants.The number of eggs on transgenic cotton plants were calculated to be 0.1%–0.12 per plant compared with the non-transgenic plants where egg number was calculated to be 0.90–1.00 per plant.Conclusion Based on these findings,it can be concluded that the chemically synthesized barley chitinase genes(ch1 and chi2)have the potential to be effective against insects with chitin exoskeletons,including whiteflies.The transgenic cotton plants expressing these genes showed increased resistance to whiteflies,resulting in reduced egg numbers and higher mortality rates.

Neotropical electric fishes(Gymnotiformes)as model organisms for bioassays

Electric fishes(Gymnotiformes)inhabit Central and South America and form a relatively large group with more than 200 species.Besides a taxonomic challenge due to their still unresolved systematic,wide distribution and the variety of habitats they occupy,these fishes have been intensively studied due to their peculiar use of bioelectricity for electrolocation and communication.Conventional analysis of cells,tissues and organs have been complemented with the studies on the electric organ discharges of these fishes.This review compiles the results of 13 bioassays developed during the last 50 years,which used the quickness,low costs and functionality of the bioelectric data collection of Gymnotiformes to evaluate the effects of environmental contaminants and neuroactive drugs.

Determination of estrogenic activity in the river Chienti(Marche Region, Italy) by using in vivo and in vitro bioassays

Environmental estrogen-like compounds（i.e. xenoestrogens） are a variety of pollutants,ranging from synthetic to natural occurring molecules, that are found in surface and waste waters over a wide range of concentrations. In aquatic environment, the overall estrogenic activity is often due to the presence of a mixture of chemicals and their degraded products which can induce synergistic effects. Current strategies for monitoring estrogen-like chemicals are based on the use of a battery of in vivo and in vitro ecotoxicological tests. In this regard, the aim of the present work was to carry out a bio-monitoring study for testing estrogenicity of the Chienti river（Marche Region, Italy） by using both an E-screen and a vitellogenin（Vtg） induction assay in juvenile goldfish. Three sites were used for analysis,localized at the mouth（sampling point 1）, in the middle（sampling point 2） and at the origin（sampling point 3） of Chienti river. For most of the water samples（i.e. samples collected at sampling points 2 and 3）, clear estrogenic activity was detected in the E-screen assay suggesting different proliferation activities in function of the collecting site. In contrast, the Vtg ELISA demonstrated that water samples collected from each sampling point were estrogenic. Overall, we showed for the first time that the estrogenic activities in water samples from the Chienti river were significant in both in vivo and in vitro; we also observed a different sensitivity between bioassays.

Emerging barcode particles for multiplex bioassays

With the increasing demand for multiplex and high-throughput analysis of large numbers of biomolecules,multiplex technology becomes a promising tool for carrying out thousands of individual reactions at the same time for large-scale biological analysis. Among current technologies,suspension arrays based on appropriate barcode particles have been popularly used in multiplex bioassays of many research fields with the ability of unique encoding, such as in the clinical, medicinal, nutritional, and environmental fields.Besides the unique form of barcode, these particles have higher flexibility, better sensitivity, and faster reaction kinetics. In this review, we present some examples of typical barcode particles that are divided into different groups depending on how they are encoded and their applications in multiplex bioassays for different targets such as proteins,DNA and RNA sequences, and cells. The bioassays for monitoring food safety, drug research, and clinical diagnosis are also described.

Enhancing the response of CALUX and CAFLUX cell bioassays for quantitative detection of dioxin-like compounds

Reporter genes produce a protein product in transfected cells that can be easily measured in intact or lysed cells and they have been extensively used in numerous basic and applied research applications.Over the past 10 years,reporter gene assays have been widely accepted and used for analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like compounds in various types of matrices,such as biological,environmental,food and feed samples,given that high-resolution instrumental analysis techniques are impractical for large-scale screening analysis.The most sensitive cell-based reporter gene bioassay systems developed are the mechanism-based CALUX(Chemically Activated Luciferase Expression) and CAFLUX(Chemically Activated Fluorescent Expression) bioassays,which utilize recombinant cell lines containing stably transfected dioxin(AhR) responsive firefly luciferase or enhanced green fluorescent protein(EGFP) reporter genes,respectively.While the current CALUX and CAFLUX bioassays are very sensitive,increasing their lower limit of sensitivity,magnitude of response and dynamic range for chemical detection would significantly increase their utility,particularly for those samples that contain low levels of dioxin-like HAHs(i.e.,serum) .In this study,we report that the addition of modulators of cell signaling pathways or modification of cell culture conditions results in significant improvement in the magnitude and overall responsiveness of the existing CALUX and CAFLUX cell bioassays.

A Shrinkage Estimator for Combination of Bioassays

A shrinkage estimator and a maximum likelihood estimator are proposed in this paper for combination of bioassays. The shrinkage estimator is obtained in closed form which incorporates prior information just on the common log relative potency after the homogeneity test for combination of bioassays is accepted. It is a practical improvement over other estimators which require iterative procedure to obtain the estimator for the relative potency. A real data is also used to show the superiorities for the newly-proposed procedures.

Assessment of the efficacy of an advanced tertiary sewage treatment plant to remove biologically active chemicals using endocrine and genotoxicity bioassays

There has been much effort to assess the efficacy of sewage treatment plants to remove chemicals with estrogenic activity,but other modes of toxicity have received less attention.This study assessed the efficacy of advanced tertiary technologies to remove estrogen receptor(ER),aryl hydrocarbon receptor(AhR),retinoic receptor(RAR)agonists and genotoxicity using recombinant gene bioassays.Untreated sewage contained ER,AhR and RAR agonists and was genotoxic.Activated sludge treatment removed over 69%of the ER,AhR and RAR aqueous phase activities.Ozonation and biologically activated carbon processes removed genotoxicity and most receptor agonists to below detection limits.Estrogenic activity was associated with the semi-polar fraction of the aqueous phase and non-polar phase of the influent(maximum 30%).AhR and RAR activities were found in both the aqueous and particulate phases of influent.Only RAR activity was frequently found in the polar fraction of aqueous and particulate phases of the process effluent.In the influent,the greatest RAR activity was found in the polar fraction of the aqueous phase(>65%).Genotoxic activity was detected in all influent fractions but rapidly decreased.The results showed that ER,AhR and RAR agonists were greatly reduced by the advanced tertiary treatment processes.

Protection of Allergic Asthma in Mice by Black Rice Bran Bioprocessed with Shiitake Mushroom Mycelia

We evaluated the potential of orally fed new food formulations to inhibit biomarkers reported to be involved in the causes of allergic asthma in mice. Asthma, a serious non-communicable disease, affects both adults and children and can be undertreated. New functional foods could provide therapeutic approaches. Here, the anti-asthma mechanism of a new functional food and three isolated fractions produced by bioprocessing black rice bran with shiitake mushroom mycelia was evaluated in mast cells, B cells, and orally fed mice and compared with non-bioprocessed black rice bran. In vitro, the treatments inhibited RBL-2H3 cell degranulation and immunoglobulin E (IgE) production. The in vitro anti-asthma effects were confirmed in orally fed mice following asthma induction by alumina and chicken egg ovalbumin (OVA). The suppression of asthma resulted from the inhibition of inflammation- and immune-related substances, including OVA-specific IgE, thymic stromal lymphopoietin, eotaxin, leukotriene C4, prostaglandin D2, and vascular cell adhesion molecule-1 in bronchoalveolar lavage fluid and serum. The treatment also reversed the thickening of the lung airway wall. The inflammation and asthma inhibition seems to be regulated by the balance of the T-helper cells’ Th1/Th2 immune response and the inhibition of multiple biomarkers associated with the cause of asthma. Future human clinical studies with adults and children should determine the potential therapeutic value of the anti-asthma effects of the new functional foods.

Advances on biological evaluation methods of programmed cell death protein-1/ligand-1 inhibitors

Immuno-oncology represents a groundbreaking and well-established field within cancer treatment.Among the various immuno-oncology targets,the exploration of programmed cell death-1/ligand-1 for drug discovery has proven to be one of the most successful endeavors.Remarkably,it took nearly 30 years from the initial target identification to the clinical approval of monoclonal antibodies.Providing suitable and reliable bioassays for drug candidate evaluation is of paramount importance throughout the early stages of drug discovery,from lead compound identification to in vivo efficacy testing.This assay review aims to shed light on diverse assays reported in the literature for testing antagonism activity and efficacy of programmed cell death-1/ligand-1 inhibitors.Each of these assays possesses inherent advantages and can be applied in different research scenarios.The insights presented in this summary can serve as a valuable resource for scientists in this field,aiding in the selection of appropriate assays for their specific investigations.

Toxic and Antifeedant Effects of Different Pesticidal Plant Extracts against Beet Armyworm (Spodoptera exigua)

The beet armyworm(BAW),Spodoptera exigua(Lepidoptera:Noctuidae)is a highly destructive pest of vegetables and field crops.Management of beet armyworm primarily relies on synthetic pesticides,which is threatening the beneficial community and environment.Most importantly,the BAW developed resistance to synthetic pesticides with making it difficult to manage.Therefore,alternative and environment-friendly pest management tactics are urgently required.The use of pesticidal plant extracts provides an effective way for a sustainable pest management program.To evaluate the use of pesticidal plant extracts against BAW,we selected six plant species(Lantana camara,Aloe vera,Azadirachta indica,Cymbopogon citratus,Nicotiana tabacum,and Ocimum basilicum)for initial screening experiment.Four out of six plant species such as A.indica,N.tabacum,C.citratus and O.basilicum showed promising mortality of more than 50%.Therefore,we selected these four plant extracts for the subsequent experiments.Through contact bioassay,A.indica showed high mortality 66.63%,followed by the N.tabacum 53.33%,at 10%w/v concentration.Similarly,N.tabacum showed the highest mortality rate,66%at 10%w/v concentration,followed by the A.indica 46%through feeding bioassay.Furthermore,the feeding deterrence assay showed that C.citratus had a high antifeedant index(−50)followed by A.indica(−39),and N.tabacum(−28).In living plant assay,the N.tabacum extract showed a low mean damage score 3.6 on living cotton plant followed by C.citratus 4.5 and A.indica 5.5.Hence,extracts of three plant species provided promising results against the BAW,which can minimize the use of synthetic chemicals,particularly for small landholding farmers.Further studies are also required to evaluate the effects of these plant extract against BAW on cotton plants under field conditions to optimize the further use.

Cellular Growth Dynamics Affects Allelopathic Activity in Coffee Cell Culture

Cellular growth dynamics and allelopathic activity in coffee cell cultures were examined as follows: First, we compared allelopathic activity of seven woody plant calli, Coffea canephora, Derris indica, Ficus carica L., Juniperus conferta, Prunus persica, Punica granatum, and Sonneratia ovata, using a modified “sandwich method bioassay” and found that coffee callus showed the strongest growth inhibition to lettuce seedling nearly 90% of hypocotyl and 96% of root. This coffee callus actively proliferated, with a 21-fold increase during five weeks of subculture, with a growth curve comprising two typical phases: a lag phase of 0 - 2 weeks of culture and an exponential phase of 3 - 5 weeks of culture. Allelopathic activity varied depending on the growth phase of the coffee callus. The strongest allelopathic activity was detected in 1 - 2-week-old callus showing nearly 100% inhibitory effect on lettuce seedling growth. As the allelopathic activity of coffee calli is extremely high, beyond the natural level in coffee leaves and green beans, we focused on analyzing the allelopathic activity of its aqueous extracts using high-performance liquid chromatography. Several prominent peaks, including two reference alkaloids, theobromine and caffeine, which are known allelochemicals in coffee plants, and three distinct unknown peaks were identified at 270 nm in coffee calli during the lag phase (1 - 2 weeks of culture). The higher value of the total phenolic content in the lag phase also suggested a key biosynthetic pathway in relation to the allelopathic activity of coffee callus will be activated in the lag phase.

Determination of the Persistence in Soil of the Herbicide Indaziflam Applied on Sugarcane Crop under Brazilian Conditions

The sugar beet,Beta vulgaris L.(cv.Early Wonder),was selected as a plant test for the herbicide indaziflam and used to determine the persistence of this herbicide under field conditions in the sugarcane crop under Brazilian conditions.A randomized block design with four treatments was used:weeded control and Indaziflam 75,100 and 200 g/ha,arranged in a randomized block design with four repetitions.For the determination of persistence,soil samples were taken at sixteen times:0,30,74,99,134,167,195,224,264,295,327,365,406,454,491 and 522 DAT(Days After Treatments).To determine the persistence,the bioassay methodology was used with sugar beet plant test.The persistence in the soil of Indaziflam,as a function of the treatments was,respectively:365 DAT,150 g/ha;454 DAT,200 g/ha and 491 DAT,400 g/ha.

Cancer Chemopreventive Retinoids: Validation and Analysis of in Vivo and in Vitro Bioassay Results

Several natural and synthetic retinoids (vitamin-A derived analogies) were examined for their potential anti-cancer activity in both in vivo animal models and a novel in vitro human keratinocyte clonal growth bioassay system. The natural retinoids included all-trans-retinoic (RA), 13-cis-retinoic acid, 4-oxoretinoic acid, and retinol. Among the synthetic retinoids tested were all trans N-(4-hydroxy(phenyl)retinamide, 3-substituted oxoretinoic acids, and 13 cis-N-ethylretinamide. The animal models employed were: 1) vitamin A-deficient hamster tracheal organ assay (HTOC);2) the benzo(α)pyrene-induced squamous metaplasia in a hamster tracheal organ system (BP-HTOC);3) the mouse skin tumor promoter (TPA)-induced ornithine decarboxylase enzyme assay(ODC);4) the mouse skin papilloma (MPA) assay;and 5) a novel retinoid bioassay in which retinoids display IC50 values to inhibit clonal growth of NHK. All-trans-RA, 4-oxoretinoic acid and retinol were consistently more active than any of the synthetic derivatives in all bioassays tested. A statistical model was developed and significant positive correlations were found between: 1) ED50 values in the HTOC system and reduction in TPA-induced ODC enzyme activity;2) tumors per animal in the MPA bioassay and suppression of TPA-induced ODC activity;and 3) a positive correlation between suppression of tumors per animal in the MPA assay, and retinoid inhibition of keratinocyte clonal growth. Test retinoids, were tested for their capacity to inhibit the clonal growth of a squamous carcinoma cell line (SCC-25), which were found to be 2 - 3 logs less sensitive for each tested retinoid than the corresponding activity against NHK cells. Antineoplastic retinoid drugs were reviewed.

Effect of Allelochemicals of Chinese-fir root extracted by supercritical CO_2 extraction on Chinese fir

Allelochemicals of Chinese-fir root was extracted by technology ofsupercritical CO_2 extraction under orthogonal experiment design, and it was used to analyzeallelopathic activity of Chinese-fir through bioassay of seed germination. The results showed thatas to the available rate of allelochemicals, the pressure and temperature of extraction were themost important factors. The allelochemicals of Chinese-fir root extracted by pure CO_2 and ethanolmixed with CO_2 have different allelopathic activities to seed germination, and the allelochemicalsextracted by ethanol mixed with CO_2 had stronger inhibitory effects on seed germination than thatextracted by pure CO_2.

Triterpenoid Saponins from Eclipta prostrata L.

Five triterpenoid saponins were isolated from the Chinese traditional medicine Eclipta prostrata L.. On the basis of their chemical properties and spectral data, they were identified as eclalbasaponins II(1), I(2), III(3), 3-O-[b-D-glucopyranosyl(12)-b-D-glucopyranosyl]-16a-ethoxy-olean-12-ene-28-oic acid-28-O-b-D-glu-copyranoside(4) and 3-O-[(2-O-sulfuryl-b-D-glucopyranosyl)(12)-b-D-glucopyranosyl]-echinocystic acid-28-O-b-D-glucopyranoside(5). Compounds 4 and 5 are new compounds and named eclalbasaponins XI and XII, respectively. Compounds 1 and 5 induced morphological deformation of Pyricularia oryzae mycelia.