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Radiation exposure to immune system induces imbalance in cytokines expression involved in Th1/Th2 homeostasis perturbations. In the present study, N-acetyl tryptophan glucoside (NATG), a bacterial secondary metabolite, was evaluated for its possible radioprotective potential to immune system using J774A.1 murine macrophages. In this study, expression of IFN-γ, TNF-α, IL-10, IL-2, IL-12, IL-13 and IL-17A cytokines was analyzed in irradiated and NATG pretreated cells using ELISA assay. Results of the study indicated that irradiated macrophages (NK-1Rcells) pretreated with NATG showed higher (p < .05) survival at all observed time-intervals (2 h-48 h) as compared to irradiated (20Gy) cells that were not pretreated with NATG. However, NATG pretreatment to irradiated HEK293T cells (that did not express NK-1Receptor) did not provide significant survival, suggesting NK-1R involvement in NATG-mediated radioprotection. Cytokine expression analysis demonstrated that NATG pre-treated plus irradiated J774A.1 murine macrophages exhibited increased IFN-γ levels (∼90%) with significant decrease in TNF-α at 24h as compared to irradiated cells. Further, significant decrease (∼20%) in IL-10 and IL-2 (∼26%) levels was observed in irradiated macrophages pretreated with NATG as compared to only irradiated cells. A sharp improvement in IL-17A (∼92%) and IL-12 (∼116%) expression was observed in irradiated macrophages pretreated with NATG as compared to only irradiated cells. Hence, NATG pre-treatment to irradiated macrophages induced IFN-γ, IL-17A and IL-12 expression, but suppresses TNF-α, IL-10 and IL-2 expressions. Conclusively, NATG pretreatment overcomes radiation-induced Th2 immune response by improving Th1 responsive cytoprotective cytokines IFN-γ, IL-17A and IL-12 in irradiated macrophages possibly by NK-1R antagonistic mechanism, and thus contributes to radioprotection.

Allyl isothiocyanate (AITC), a glucosinolates’ hydrolytic product, was studied for its anti-insect potential against an economically important, destructive tephritid pest, Zeugodacus cucurbitae (Coquillett). The first, second and third instar maggots of the pest were fed on artificial diets amended with varied concentrations of AITC viz. 5 ppm, 25 ppm, 50 ppm, 100 ppm, 150 ppm and 200 ppm with DMSO (0.5%) as control. Results revealed high larval mortality, alteration of larval period, prolongation of pupal and total developmental periods in all instars of the maggots treated with AITC as compared to controls. Percent pupation and percent adult emergence decreased in all larval instars. Growth indices viz. Larval Growth Index (LGI) and Total Growth Index (TGI) were negatively affected. Anti-nutritional/post ingestive toxicity of AITC was also revealed by the decrease in Food Assimilation (FA) and Mean Relative Growth rate (MRGR) values with respect to control. Profiles of PO (Phenol oxidase) and other detoxifying enzymes including SOD (Superoxide dismutases), CAT (Catalases), GST (Glutathione-S-transferases), EST (Esterases), AKP (Alkaline phosphatases) and ACP (Acid phosphatases) were also significantly influenced. The genotoxic effect of AITC was also evaluated by conducting comet assays at LC30 and LC50. Significant DNA damage in hemocytes was reflected by increase in Tail length (μm), Percent Tail DNA, Tail Moment (TM) and Olive Tail Moment (OTM) as compared to controls. The results indicated high potential of AITC as biopesticide for pest management.

Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae) is a serious agro‐economic pest of cucurbits around the world. Management of tephritid fruit flies is till date mainly dependent on the use of chemical pesticides. In a rising concern about environment quality and rapid development of resistance in insect pests, biological control of insect pests is being contemplated, and in response, research approaches are constantly evolving. Various naturally occurring control agents of melon fruit fly such as parasitoids, bacteria, fungi and nematodes have potential in the management of Z. cucurbitae. Many parasitoids including Psyttalia fletcheri, Fopius arisanus, Dirhinus giffardii and Spalangia endius are known to attack various life stages of Z. cucurbitae. Although parasitoids are being principally exploited for control of Z. cucurbitae, various other entomopathogens such as fungi (Beauveria bassiana, Paecilomyces fumosoroseus, Metarhizium anisopliae), bacteria (Bacillus thuringiensis), nematodes (Heterorhabditis indica, Steinernema feltiae) and microbial toxins/products (spinosad, avermectin) are being investigated or used for biological control. The development of farming methodologies with greater credence on ecosystem services such as biological control of Z. cucurbitae will increase sustainability of agroecosystems. This review provides a concise compilation of these biological control agents along with their effectiveness and will help researchers in designing various integrated pest management strategies against Z. cucurbitae that involve biological control agents.

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