Efecto letal agudo de los insecticidas en formulación comercial Imidacloprid, Spinosad y Thiocyclam hidrogenoxalato en obreras de Bombus atratus (Hymenoptera: Apidae) / Acute lethal effect of the commercial formulation of the insecticides Imidacloprid, Spinosad y Thiocyclam hidrogenoxalate in Bombus atratus (Hymenoptera: Apidae) workers

Resumen:Los efectos de los insecticidas sobre las abejas han cobrado gran atención a nivel mundial, sin embargo, son pocos los estudios sobre el efecto de estos agroquímicos en abejas Neotropicales. Bombus atratus es una especie neotropical, distribuida ampliamente en los Andes y es considerado un polinizador importante de ecosistemas y agroecosistemas altoandinos. Sin embargo, al igual que muchas especies silvestres, se desconoce el efecto de los insecticidas en B. atratus. Teniendo en cuenta lo anterior, el presente trabajo determinó la dosis letal media aguda (DL50) por exposición tópica y oral de las formulaciones comerciales de los insecticidas con los ingredientes activos Imidacloprid, Spinosad y Thiocyclam hidrogenoxalato, ampliamente utilizados para el control de plagas de cultivos importantes en Colombia. Las pruebas DL50 se realizaron a partir de modificaciones de los lineamientos establecidos por la EPPO y OEDE para estas pruebas en Apis mellifera. Se evaluaron 5 dosis para cada insecticida y exposición. Se evaluaron 25 obreras de tamaño medio en cada dosis por duplicado. La mortalidad se registró a las 24, 48 y 72 horas después del experimento. Los datos fueron analizados con el modelo de regresión Probit. Para el Imidacloprid la DL50 tópica y oral fue de 0.048 µg/abeja y 0.010 µg/abeja respectivamente. Para el Thiocyclam hidrogenoxalato la DL50 tópica y oral fue de 0.244 µg/abeja y de 0.056 µg/abeja respectivamente. Para el Spinosad, la DL50 por exposición oral correspondió a 0.28 µg/abeja. No fue posible establecer la DL50 por exposición tópica. A partir del cálculo del Cociente de Riesgo (HQ) e Índice de Toxicidad Relativa, los tres ingredientes activos son altamente tóxicos. Se analiza y discute el riesgo debido al uso de los productos evaluados a partir de la naturaleza química de los insecticidas.

Abstract:The effect of insecticides on bees has gained great attention, however, there are few studies that explore this issue on Neotropical bees. Bombus atratus is a neotropical species broadly distributed in Colombia and is considered an important pollinator of both Andean ecosystems and agroecosystems. However, as for many wild bees species, the effect of insecticides on B. atratus is unknow. In this study we determined the acute median lethal dose (LD50) of commercial formulations of insecticides Imidacloprid, Spinosad and Thiocyclam hydrogen oxalate, widely used in Colombia to control several pests of important crops. The LD50 was carried out by oral and contact routes, following and modifying the EPPO and OECD guidelines to perform LD50 on A. mellifera. We evaluated five doses for each route and insecticide, in a total of 25 medium-size workers for each dose by duplicate. Mortality was registered at 24, 48 and 72 hours after the experiment; and data were analyzed with the Probit regression model. For Imidacloprid, contacts and oral LD50 were 0.048 µg/bee and 0.010 µg/bee, respectively. For Thiocyclam hydrogen oxalate, topical and oral LD50 were 0.244 µg/bee and 0.056 µg/bee, respectively. For Spinosad, the oral LD50 corresponded to 0.28 µg/bee; it was not possible to establish the LD50 for the contact route. The Hazard Quotient (HQ) and Index of Relative Toxicity indicated that all three active ingredients are highly toxic. We discussed the risk of the insecticides use on B. atratus, considering their chemical nature. Rev. Biol. Trop. 64 (4): 1737-1745. Epub 2016 December 01.

Apoptosis of human lung carcinoma cell line EBC-1 induced by N, N'-di-(m-methylphenyl)-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboamide and its molecular mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study whether N, N'-di-(m-methylphenyi)-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboamide (ZGDHu-1) inhibits proliferation and induces apoptosis in human lung carcinoma cell line EBC-1 cells and its molecular mechanism.</p><p><b>METHODS</b>Different concentrations of ZGDHu-1 and different times of culture were used to treat EBC-1 cells in vitro. The inhibition of proliferation was measured by BrdU-ELISA. Cell apoptosis was detected by Annexin V/PI staining and cellular DNA fragmentation ELISA. Phosphorylated p38MAPK and STAT3 were examined by flow cytometry. The protein expressions of bcl-2, bax, p53, Fas, and caspase-3 were detected by Western blot analysis.</p><p><b>RESULTS</b>ZGDHu-1 inhibited EBC-1 cell proliferation within a certain range of treating times and does, with a 24 h IC(50) of (295 ± 25) ng/ml, 48 h of (112 ± 8) ng/ml and 72 h of (23 ± 2) ng/ml. The EBC-1 cell apoptosis was confirmed by Annexin V/PI labeling and cellular DNA fragmentation ELISA in a dose-related manner. When EBC-1 cells were treated with 50, 200, and 500 ng/ml ZGDHu-1 for 48 h, the expression rates of phosphor-p38MAPK protein were 67.4%, 88.2%, 91.1%, respectively, and that of the control was 10.6%. That of STAT3 protein were 56.5%, 43.6% and 34.6%, respectively, and that of the control was 89.1%. The expression of bax, p53 and Fas protein was significantly increased, that of bcl-2 was not changed, and that of caspase-3 was significantly decreased by the ZGDHu-1 treatment.</p><p><b>CONCLUSION</b>ZGDHu-1 can inhibit proliferation and induce apoptosis in EBC-1 cells. The mitochondrial pathway mediated by Fas may be one of its mechanisms. The apoptosis of EBC-1 cells may associate with up-regulation of phosphor-p38MAPK and down-regulation of phosphor-STAT3 in the cells.</p>

Effects of matrix metalloproteinase 9 inhibition on the blood brain barrier and inflammation in rats following cardiopulmonary resuscitation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neuroprotective strategies following cardiopulmonary resuscitation (CPR) are an important focus in emergency and critical care medicine. Matrix metalloproteinases (MMPs), especially MMP9 attracted much attention because of its function in focal brain ischemia/reperfusion injury. In the focal cerebral ischemia model in rats, SB-3CT can suppress the expression of MMP9, relieving brain edema, and there was no studies on global cerebral ischemia-reperfusion injury after CPR.</p><p><b>METHODS</b>One hundred and twenty rats were randomly assigned to sham-operated (n = 40), resuscitation treatment (n = 40), and resuscitation control (n = 40) groups. Sham-operated group rats were anesthetized only and intubated tracheally, while the resuscitation treatment and resuscitation control groups also received cardiac arrest by asphyxiation. In the resuscitation treatment group, SB-3CT was injected intraperitoneally after restoring spontaneous circulation (ROSC), defined as restoration of supraventricular rhythm and mean arterial pressure (MAP) > or = 60 mm Hg for more than 5 minutes. The resuscitation control group also implemented ROSC without injection of SB-3CT. The rats were executed and samples were taken immediately after death, then at 3, 9, 24, and 48 hours (n = 8). Brain tissue expression of MMP9 protein, MMP9 mRNA, water content, Evans blue content, TNF-alpha, IL-1, and IL-6 was measured, and the brain tissue ultramicrostructure studied with electron microscopy.</p><p><b>RESULTS</b>In the resuscitation control group, brain tissue expression of MMP9 protein and mRNA, water content, Evans blue content, TNF-alpha, IL-1, and IL-6 were significantly elevated at 3 hours, and peaked at 24 hours after resuscitation, when compared with the sham-operated group (P < 0.05). Tissue ultramicrostructure also changed in the resuscitation control group. By contrast, although all these indexes were increased in the resuscitation treatment group compared with the sham-operated group (P < 0.05), they were lower than in the resuscitation control group (P < 0.05).</p><p><b>CONCLUSIONS</b>Expression of MMP9 protein and mRNA, water content, Evans blue content, TNF-alpha, IL-1, and IL-6 increased in rat brain tissue after CPR, indicating disruption of the blood-brain barrier and excess inflammatory reaction. MMP9 expression was reduced with SB-3CT, resulting in reduced brain injury.</p>

Vilsmeier - Haack reaction cyclizatlon of N-substituted -3- acetyl indole phenyl hydrazones and their reactions

New 1-phenyl -3- [N-Substitutcd indol- 3-yl] [1H] pyrazolc -4-carboxaldehydes 4a-c were synthesized in 80-85% yield via Vilsmeier - Haack reaction cyclization of N-substitutcd -3- acetyl indole phenyl hydrazones using 2.5 equivalent ratio of phosphrous oxychloride and dimethyl formamide. Reaction of compounds 4a-c with urea, thiourea and different compounds, namely ethyl acetoacetate, acetyl acetone and ethyl cyanoacctatc gave the corresponding pyrimidinc-2-one and pyrimidine-2-thionc derivatives 5a,b-13a,b. Moreover, condensation of compounds 4a-c with active methylene groups of different compounds, namely malononitrile, ethyl cyanoacetate and 2-cyanoacetohydrazide under different conditions led to the formation of pyridine derivatives 15a,b,c-21a,b

ZGDHu-1-inducing apoptosis of SHI-1 leukemia cells and its molecular mechanism / 中国实验血液学杂志

The aim of study was to investigate the mechanism of N, N'-di-(m-methylphenyl)-3, 6-dimethyl-1, 4-dihydro-1, 2, 4, 5-tetrazine-1, 4-dicarboamide (ZGDHu-1) inducing apoptosis in SHI-1 human leukemia cell line. Different concentrations of ZGDHu-1 and different times of culture were used to treat SHI-1 cells; the apoptosis of SHI-1 cells was analyzed by morphology, DNA agarose gel electrophoresis, DNA content detection, Annexin-V/PI and Hoechst33258 labeling method, the mitochondrial transmembrane potential (Delta Psi m) were measured by dihydrorhodamin 123, and expressions of bcl-2, bax, Fas, p53 and mitochondrial membrane protein were analyzed by flow cytometry, while the bcl-2, bax and p53 gene were analyzed by RT-PCR. The transcriptional level of hTERT-mRNA was measured by real-time fluorescence quantitative RT-PCR. The results showed that after exposure to ZGDHu-1, SHI-1 cells were induced to apoptosis in a time-and does-dependent manner. SHI-1 cell apoptosis was confirmed by typical cell morphology, DNA fragmentation, sub-G(1) phase, Hoechst33258 and Annexin-V/PI labeling etc. The expression of bax, bax/bcl-2, p53 and Fas gene significantly increased and bcl-2 slightly decreased. ZGDHu-1 could increased the expression of mitochondrial membrane protein in a dose-dependent manner while Delta Psi m reduced. The expression of hTERT-mRNA significantly decreased. It is concluded that ZGDHu-1 can up-regulate the expression of p53, bax and bax/bcl-2. The mitochondrial pathway mediated by descent of mitochondrial transmembrane potential may be one of the mechanisms inducing apoptosis by ZGDHu-1, in which Fas gene also participates. Telomerase may be an effective gene target for anti-tumour effect of ZGDHu-1.

Effect of ZGDHu-1 on proliferation and apoptosis of A549 cells in vitro and antitumor activity in vivo / 药学学报

This study is to explore the mechanism and effect of N, N'-di-(m-methylphenyl)-3, 6-dimethyl-1, 4-dihydro-1, 2, 4, 5-tetrazine-1, 4-dicarboamide (ZGDHu-1) on proliferation and apoptosis of A549 cells in vitro and on A549 xenograft tumor in nude mice. With different concentrations of ZGDHu-1 at different times were used to treat A549 cells in vitro. The proliferation was determined by living cell count, SRB assay and Brdu-ELISA. Cell apoptosis was determined by cell morphology, DNA agarose gel electrophoresis, DNA content, Annexin V/PI and Hoechst 33258 labeling method. The nude mice model of A549 xenograft tumor was established by subcutaneous inoculation. The suppression activity of ZGDHu-1 by intraperitoneal injection on xenograft mice model was detected. The expressions of bcl-2, bax and p53 gene and protein were analyzed by RT-PCR and flow cytometry. ZGDHu-1 can inhibit A549 cell proliferation viability within a certain range of treating time and does, and a majority of A549 cells were arrested in G2-M phase. The A549 cells apoptosis was confirmed by typical cell morphology, DNA fragment, Sub G1 phase, Hoechst 33258 and Annexin V/PI labeling method with a time and dose related manner. When the xenograft tumor mice model were treated with 10, 20 and 40 mg x kg(-1) ZGDHu-1 for 14 days, the tumor growth inhibition rate were 43.7%, 56.9% and 60.0%, respectively. The expression of bax, bax/bcl-2 and p53 gene and protein increased significantly and bcl-2 decreased slightly by the treatment of ZGDHu-1. ZGDHu-1 can significantly suppress the growth of A549 xenograft tumor in vivo and inhibited proliferation by inducing tumor cell apoptosis in vitro. The mechanism may associate with its up-regulation of bax and p53 during the apoptosis process.

Effects of N, N-di-(m-methylphenyl)-3, 6-dimethyl-1, 4-dihydro-1,2,4, 5-tetrazine-1,4-dicarboxamide (ZGDhu-1) on SHI-1 leukemia cells in vitro / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the effect of ZGDHu-1 on proliferation, differentiation and apoptosis in SHI-1 human leukemia cell line and explore its possible mechanism. Methods SHI-1 cells were cultured with different concentration of ZGDHu-1 and for different time. The cell proliferation was analysed by cell counting, alive cell count, MTT assay and Brdu-ELISA. Cell apoptosis was analysed by morphology, DNA content, Annexin-V/PI and Hoechst 33258 labeling method. Cell differentiation were assayed by morphology,expression of CD11b,CD14 and CD64 and NBT reduction. The expressions of phosphorylated p38MAPK or STAT3 were analysed by flow cytometry.</p><p><b>RESULTS</b>ZGDHu-1 inhibited SHI-1 cell proliferation in a time and dose dependent manner, the IC50- 48 h and IC50- 72 h were 250 ng/ml and 85 ng/ml, respectively. The majority of SHI-1 cells were arrested in G2/M phase. 48h after treated with 200 ng/ml ZGDHu-1, and those in G2/M phase accounted for (48.4 +/- 2.1)%. The SHI-1 cells apoptosis was increased with a time- and does-dependent manner. The morphology of SHI-1 cells cultured with 2-50 ng/ml ZGDHu-1 for three days become more mature with higher NBT positivity and up-regulated expressions of CD11b,CD14 and CD64. The expression of phosphor-p38MAPK was increased and phosphor-STAT3 down-regulated by the treatment of ZGDHu-1.</p><p><b>CONCLUSION</b>ZGDHu-1 can inhibit SHI-1 cell proliferation and induce the cell differentiation and apoptosis. The mechanism may associate with its up-regulation of phosphor-p38MAPK and down-regulation phosphor-STAT3.</p>

Effects of N, N'-Di-(m-methylphenyi)-3, 6-dimethyl-1, 4-dihydro-1, 2, 4, 5-tetrazine-1, 4-dicarboamide on proliferation, apoptosis and differentiation of NB4 leukemia cells in vitro / 中国实验血液学杂志

The purpose of this study was to explore the effect of N, N'-di-(m-methylphenyi)-3, 6-dimethyl-1, 4-dihydro-1, 2, 4, 5-tetrazine-1, 4-dicarboamide (ZGDHu-1) on proliferation, differentiation and apoptosis in NB4 human leukemia cell line and its possible mechanism. Different concentrations of ZGDHu-1 and the different time of cultivation were used to treat NB4 cells. The proliferation inhibition of NB4 cells was analysed by cell counting, alive cell count, MTT assay. Cell apoptosis was determined by cell morphology, DNA agarose gel electrophoresis, DNA content, Annexin-V/PI and Hoechst 33258 labeling method. The analysis of cell morphological change, expression of CD11b, CD13 and NBT reduction were performed to evaluate the differentiation of NB4 cells. The expressions of bcl-2, bax and phosphorylated p38MAPK or STAT3 were detected by flow cytometry. While the expression of hTERT mRNA in transcriptional level was measured by fluorescence quantitative RT-PCR. The results showed that ZGDHu-1 could inhibit NB4 cell proliferation viability within a certain range of treating time and does, IC(50) values at 48 and 72 hours were 450 ng/ml and 200 ng/ml respectively. A majority of NB4 cells were arrested in G(2/M) phase and a progressive decline of cells was seen in G(0/1). The NB4 cells apoptosis was confirmed by cell typical cell morphology, DNA fragments and sub-G(1) phase peak as well as Hoechst33258 and Annexin-V/PI labeling method with a time-dose-related manner. The morphology of NB4 cells cultured in the presence of 2 - 100 ng/ml ZGDHu-1 for three days was more mature with higher NBT positivity and expressions of CD11b and CD13 than those in control. The expression of phosphor-p38MAPK and bax was increased while phosphor-STAT3 and bcl-2 were unchanged by the treatment of ZGDHu-1. ZGDHu-1 could decrease the expression of hTERT-mRNA in a dose-dependent manner. It is concluded that ZGDHu-1 can inhibit proliferation, induce differentiation and apoptosis of NB4 cells. The mechanism may be associated with up-regulation of bax expression, enhancement of phosphor-p38MAPK activation and inhibition of hTERT-mRNA.