Azoxystrobin Research Articles

MANAGEMENT OF RICE BLAST WITH DIFFERENT FUNGICIDES AND POTASSIUM SILICATE UNDER IN VITRO AND IN VIVO CONDITIONS

During 2015 and 2016 cropping season investigations were carried out at Punjab Agricultural University, Ludhiana, India, with the aim to manage rice blast disease by means of different fungicides and potassium silicate under in vitro and in vivo conditions. Fungicides were tested against spore germination of Pyricularia grisea and their efficacy was determined by calculating ED50 and ED90 values. Tricyclazole (Baan 75WP) and Propiconazole (Tilt 25EC) were found to be most fungitoxic compounds and Mancozeb (Indofil Z-78 75WP) was least fungitoxic. Under in vivo conditions, fungicides and potassium silicate were applied at tillering and boot stage. It was found that the fungicide Tricyclazole (Baan 75WP) at 0.06% was most effective and provided disease control of 67.9% followed by Propiconazole (Tilt 25EC) at 0.1% with 60.3% disease control, Azoxystrobin + Difenoconazole (Amistar Top 325SC) at 0.1% with 55.1% disease control and Trifloxystrobin + Tebuconazole (Nativo 75WP) at 0.04% with 53.3% disease control. Difenoconazole (Score 25EC), Tebuconazole (Folicur 25EC) and Mancozeb (Indofil Z-78 2 75WP) were least effective. The potassium silicate applied at 40 and 50 ml/l was found effective against rice blast and significantly increased the grain yield by reducing the toppling of panicles. Thus, it can provide us with an environmentally safe alternative source to rice blast disease management.

RESISTANCE OF HELMINTHOSPORIUM SOLANI STRAINS TO SELECTED FUNGICIDES APPLIED FOR TUBER TREATMENT

Helminthosporium solani strains were isolated from potato tubers collected in Russia or taken from imported German and Dutch seed tubers. Sequences of the nuclear ribosomal genes and internal transcribed spacers (ITS) for all 24 tested strains were identical and had 100% similarity to the sequences from GenBank identified as Helminthosporium solani. The obtained molecular data confirmed the morphological identification based on the width and length of conidia, the shape of conidiophores and the colony morphology. Screening for resistance to the fungicides Score 250 SC (active ingredient difenoconazole 250 g/l), Quadris (azoxystrobin 250 g/l), Tecto 500 SC (thiabendazole 500g/l), Zeroxxe (colloidal silver particles (3 g/l) stabilized with amphoteric surfactant) was done. Agar blocks with pure cultures of the fungal strains were placed in the centre of Petri dishes containing malt agar amended with fungicide concentrations of 0.1, 1, 10, 100 and 1000 mg/l (accounted for the concentration of the active ingredient). Malt agar free of fungicide was used as the control. 2 Growth inhibition of 50% (EC50) compared to the control was detected based on the doseresponse curves. Difenoconazole (EC50 100 mg/l). Thiabendazole appears to be effective against the sensitive strains of H. solani (EC50 1000 mg/l). The sequence of their β-tubulin gene contained a SNP mutation in the 198 codon or 200 codon, translating to Gln (CAG) instead of Glu (GAG) or Tyr (TAC) instead of Phe (TTC), respectively. Thus, the resistance to thiabendazole of the Russian, European, and American strains had the same genetic background and was conferred by the same mutations.

Azoxystrobin Induces Apoptosis of Human Esophageal Squamous Cell Carcinoma KYSE-150 Cells through Triggering of the Mitochondrial Pathway.

Recent studies indicate that mitochondrial pathways of apoptosis are potential chemotherapeutic target for the treatment of esophageal cancer. Azoxystrobin (AZOX), a methoxyacrylate derived from the naturally occurring strobilurins, is a known fungicide acting as a ubiquinol oxidation (Qo) inhibitor of mitochondrial respiratory complex III. In this study, the effects of AZOX on human esophageal squamous cell carcinoma KYSE-150 cells were examined and the underlying mechanisms were investigated. AZOX exhibited inhibitory effects on the proliferation of KYSE-150 cells with inhibitory concentration 50% (IC50) of 2.42 μg/ml by 48 h treatment. Flow cytometry assessment revealed that the inhibitory effect of AZOX on KYSE-150 cell proliferation occurred with cell cycle arrest at S phase and increased cell apoptosis in time-dependent and dose-dependent manners. Cleaved poly ADP ribose polymerase (PARP), caspase-3 and caspase-9 were increased significantly by AZOX. It is worth noted that the Bcl-2/Bax ratios were decreased because of the down-regulated Bcl-2 and up-regulated Bax expression level. Meanwhile, the cytochrome c release was increased by AZOX in KYSE-150 cells. AZOX-induced cytochrome c expression and caspase-3 activation was significantly blocked by Bax Channel Blocker. Intragastric administration of AZOX effectively decreased the tumor size generated by subcutaneous inoculation of KYSE-150 cells in nude mice. Consistently, decreased Bcl-2 expression, increased cytochrome c and PARP level, and activated caspase-3 and caspase-9 were observed in the tumor samples. These results indicate that AZOX can effectively induce esophageal cancer cell apoptosis through the mitochondrial pathways of apoptosis, suggesting AZOX or its derivatives may be developed as potential chemotherapeutic agents for the treatment of esophageal cancer.

Implementation of Lean Banking and Continuous Improvement in an African Global Bank: The United Bank for Africa

In today’s marketplace, it’s much too risky to rely on the company gut for decision-making. Lean banking data analysis is an evidence-based solution that provides any innovative organization with a new view of organizational challenges with the objective to improve efficiency and data quality, effectively eliminating corporate waste. The process is an undergoing and rapid transformation in the banking industry. For an effective implementation of the process, the information technology must play an increasingly greater role in helping banks carry out marketing, sales, and channel integration initiatives, and in ensuring that banks comply with various regulatory requirements. To this end, IT in banking needs to adopt a strategic approach to managing change. This paper looks at what Information Technology Infrastructure Library (ITIL) offers to manage these corporate challenges and whether ITIL practices are sufficient to improve the Bank performance. The paper present ITIL best practices that are needed to manage risk but not sufficient to drive the Bank performance. According to Ndedi, Moutila and Tsoungui (2016), the real essence of lean is in harnessing the passion and knowledge of front-line staff and equipping them to focus on ensuring as many activities as possible within an end-to-end process support the delivery of value to the customer. The authors argued that the objectives of continuous improvement methods are to boost organizational performance; because simply meeting customer expectations is not anymore enough; customers who aren’t completely satisfied are likely to switch to another service provider. Building a culture of continuous improvement through the adoption of lean principles ensures the identification of the end-to-end process from the customer’s perspective and the design and management of those processes to ensure the smooth flow of information and material as efficiently as possible. The first part of this paper explains what the United Bank of Africa is. The second part discusses the principle of lean banking. The third part of the paper gives an overview of best practices with UBA.

Determination and validation of an aquatic Maximum Acceptable Concentration-Environmental Quality Standard (MAC-EQS) value for the agricultural fungicide azoxystrobin

The main goal of the present study was to determine and validate an aquatic Maximum Acceptable Concentration-Environmental Quality Standard (MAC-EQS) value for the agricultural fungicide azoxystrobin (AZX). Assessment factors were applied to short-term toxicity data using the lowest EC50 and after the Species Sensitivity Distribution (SSD) method. Both ways of EQS generation were applied to a freshwater toxicity dataset for AZX based on available data, and to marine toxicity datasets for AZX and Ortiva® (a commercial formulation of AZX) obtained by the present study. A high interspecific variability in AZX sensitivity was observed in all datasets, being the copepoda Eudiaptomus graciloides (LC50,48h = 38 μg L−1) and the gastropod Gibbula umbilicalis (LC50,96h = 13 μg L−1) the most sensitive freshwater and marine species, respectively. MAC-EQS values derived using the lowest EC50 (≤0.38 μg L−1) were more protective than those derived using the SSD method (≤3.2 μg L−1). After comparing the MAC-EQS values estimated in the present study to the smallest AA-EQS available, which protect against the occurrence of prolonged exposure of AZX, the MAC-EQS values derived using the lowest EC50 were considered overprotective and a MAC-EQS of 1.8 μg L−1 was validated and recommended for AZX for the water column. This value was derived from marine toxicity data, which highlights the importance of testing marine organisms. Moreover, Ortiva affects the most sensitive marine species to a greater extent than AZX, and marine species are more sensitive than freshwater species to AZX. A risk characterization ratio higher than one allowed to conclude that AZX might pose a high risk to the aquatic environment. Also, in a wider conclusion, before new pesticides are approved, we suggest to improve the Tier 1 prospective Ecological Risk Assessment by increasing the number of short-term data, and apply the SSD approach, in order to ensure the safety of aquatic organisms.

Simultaneous Determination of Seven Kinds of Fungicides in Citrus Fruits by Gas Chromatograghy/Mass Spectrometry.

A simple and accurate procedure was developed for the determination of seven fungicides, azoxystrobin (AZO), diphenyl (DP), fludioxonil (FLUDI), imazalil (IMZ), o-phenylphenol (OPP), pyrimethanil (PYRI) and thiabendazole (TBZ), in citrus fruits. The citrus fruit sample was extracted with acetonitrile and cleaned up with a graphite carbon/aminopropyl silanized silica gel solid-phase extraction cartridge using acetonitrile-toluene (3 : 1, v/v) as the eluent. Triphenylene was used as an internal standard (I.S.) at the concentration of 0.5 μg/mL. The sample solution was subjected to GC-MS utilizing the matrix-matched standard solution method. The recoveries of AZO, FLUDI, IMZ, OPP, PYRI and TBZ spiked in domestic citrus fruits (Satsuma mandarin) at the level of 0.01-10.0 μg/g were 72.8-104% and the limits of quantification were 0.01 μg/g. The recoveries of DP spiked in domestic citrus fruits at the level of 0.01-70.0 μg/g were 70.8-80.4% and the limit of quantification was 0.01 μg/g. The proposed method was applied to the determination of fungicides in citrus fruits purchased in various markets.

Identification of QoI fungicide-resistant genotypes of the wheat pathogen Zymoseptoria tritici in Algeria

Septoria tritici blotch caused by Zymoseptoria tritici is currently one of the most damaging diseases on bread and durum wheat crops worldwide. A total of 120 monoconidial isolates of this fungus were sampled in 2012 from five distinct geographical locations of Algeria (Guelma, Annaba, Constantine, Skikda and Oran) and assessed for resistance to Quinone outside Inhibitors (QoI), a widely used class of fungicides for the control of fungal diseases of wheat. Resistance was screened using a mismatch PCR assay that identified the G143A mitochondrial cytochrome b substitution associated with QoI resistance. The isolates were QoI-sensitive, since all possessed the G143 wild-type allele, except for three isolates (two from Guelma and one from Annaba), which had fungicide resistance and possessed the A143 resistant allele. QoI resistance was confirmed phenotypically using a microplate bioassay in which the resistant isolates displayed high levels of half-maximal inhibitory azoxystrobin concentrations (IC 50 s) when compared to sensitive reference isolates. Genetic fingerprinting of all isolates with microsatellite markers revealed that the three resistant isolates were distinct haplotypes, and were are not genetically distinguishable from the sensitive isolates. This study highlights QoI-resistant genotypes of Z. tritici in Algeria for the first time, and proposes a management strategy for QoI fungicide application to prevent further spread of resistance across the country or to other areas of Northern Africa.

Smart Banking: an Introduction Driven by Information Technology

The book explains how with the help of technology banks are providing innovative services by managing wide network of branches and delivery channels. It focuses on key banking activities and IT applications driving the banking processes. The book describes the inter-connection between the Core Banking Solution, delivery channels and the networking platforms facilitating online transactions between banks, customers and the business entities.

Cardiomyocyte H9c2 cells present a valuable alternative to fish lethal testing for azoxystrobin

The present study aims at identifying, among six mammalian and fish cell lines, a sensitive cell line whose in vitro median inhibitory concentration (IC50) better matches the in vivo short-term Sparus aurata median lethal concentration (LC50). IC50s and LC50 were assessed after exposure to the widely used fungicide azoxystrobin (AZX). Statistical results were relevant for most cell lines after 48 h of AZX exposure, being H9c2 the most sensitive cells, as well as the ones which provided the best prediction of fish toxicity, with a LC50,96h/IC50,48h = 0.581. H9c2 cell proliferation upon 72 h of AZX exposure revealed a LC50,96h/IC50,72h = 0.998. Therefore, identical absolute sensitivities were attained for both in vitro and in vivo assays. To conclude, the H9c2 cell-based assay is reliable and represents a suitable ethical alternative to conventional fish assays for AZX, and could be used to get valuable insights into the toxic effects of other pesticides.

Imazalil resistance in Penicillium digitatum and P. italicum causing citrus postharvest green and blue mould: Impact and options

Citrus green and blue mould, caused by Penicillium digitatum (PD) and Penicillium italicum (PI), respectively, are mostly controlled by means of postharvest fungicide applications. Currently, IMZ is regarded as the most effective fungicide in use. Effective IMZ concentrations that inhibit 50% (EC50) growth of nine PD and five PI isolates were assessed in vitro and the various isolates categorized according to their resistance (R) factors. Effective residue levels that provided 50% curative (ER50C) and protective (ER50P) control of these isolates were determined in vivo. All the PI isolates were sensitive, having EC50 values of 0.005–0.050μgmL−1. Three PD isolates were sensitive (0.027–0.038μgmL−1), while one resistant isolate was categorized as low resistant (R-factor of 19), one as moderately resistant (R-factor of 33.2), three as resistant (R-factor of 50–57.6) and one as highly resistant (R-factor of 70.7). Sensitive PD isolates had mean ER50C and ER50P values on Valencia orange fruit of 0.29 and 0.20μgg−1, and 0.33 and 0.32μgg−1 on navel fruit, respectively. ER50 values for resistant isolates did not always correlate with EC50 values and ranged from 1.22 to 4.56μgg−1 for ER50C and 1.00–6.62μgg−1 for ER50P values. ER50P values for resistant isolates could not be obtained on navel orange fruit, but ER50C values (1.42–1.65μgg−1) were similar to those obtained on Valencia fruit. The PI isolates all behaved similar to the sensitive PD isolates with ER50C and ER50P values on navel and Valencia fruit <0.38μgg−1. Alternative fungicides were assessed for the control of an IMZ sensitive, resistant and highly resistant PD isolate; these included sodium ortho-phenylpenate (SOPP), thiabendazole (TBZ), guazatine (GZT), imazalil (IMZ), pyrimethanil (PYR) and Philabuster® (PLB; a combination of IMZ and PYR), fludioxonil (FLU), azoxystrobin (AZO), Graduate®A+ (GRA; a combination of FLU and AZO) and propiconazole (PPZ). Multiple fungicide resistance was shown to IMZ, GZT, TBZ and PPZ in both resistant isolates. For the sensitive isolates, IMZ, SOPP, TBZ, GZT and PLB provided best curative control, while IMZ, GZT and PLB provided best protective control. For the IMZ-resistant isolates, SOPP, PYR and PLB gave the best curative control, while none of the fungicides provided adequate protective control.

Azoxystrobin-induced excessive reactive oxygen species (ROS) production and inhibition of photosynthesis in the unicellular green algae Chlorella vulgaris.

This study investigated the short-term toxicity of azoxystrobin (AZ), one of strobilurins used as an effective fungicidal agent to control the Asian soybean rust, on aquatic unicellular algae Chlorella vulgaris. The median percentile inhibition concentration (IC₅₀) of AZ for C. vulgaris was found to be 510 μg L(-1). We showed that the algal cells were obviously depressed or shrunk in 300 and 600 μg L(-1) AZ treatments by using the electron microscopy. Furthermore, 19, 75, and 300 μg L(-1) AZ treatments decreased the soluble protein content and chlorophyll concentrations in C. vulgaris and altered the energy-photosynthesis-related mRNA expression levels in 48- and 96-h exposure periods. Simultaneously, our results showed that AZ could increase the total antioxidant capacity (T-AOC) level and compromise superoxide dismutase (SOD), peroxidase (POD), glutathione S transferase (GST), glutathione peroxidase (GPx) activities, and glutathione (GSH) content. These situations might render C. vulgaris more vulnerable to oxidative damage. Overall, the present study indicated that AZ might be toxic to the growth of C. vulgaris, affect energy-photosynthesis-related mRNA expressions, and induce reactive oxygen species (ROS) overproduction in C. vulgaris.

Rapid Determination of Seven Fungicides in Citrus Fruits

A rapid and simple determination method of seven fungicides, thiabendazole (TBZ), pyrimethanil (PYR), o-phenylphenol (OPP), fludioxonil (FLD), azoxystrobin (AZX), imazalil (IMZ) and diphenyl (DP) in citrus fruits by LC-MS and HPLC-FL was developed. The seven fungicides were extracted with acetonitrile from citrus fruits and cleaned up with Z-Sep/C18 cartridges. The LC separation was performed on a phenyl-hexyl column with methanol-acetonitrile-10 mmol/L ammonium formate (10 : 35 : 55) as a mobile phase. The recoveries from citrus fruits fortified with the compounds at the MRLs and at 0.1 μg/g ranged from 85.4 to 106.3% and from 75.8 to 99.7%, respectively. The quantitation limits (S/N=10) were 0.03-0.07 μg/g.

Allele-Specific PCR for the Detection of Azoxystrobin Resistance in Didymella bryoniae.

Gummy stem blight (GSB), caused by the fungus Didymella bryoniae, is considered the most widespread and destructive disease of watermelon in the southeastern United States. The quinone outside-inhibiting (QoI) fungicide azoxystrobin (AZO), which inhibits mitochondrial respiration by binding to the outer, quinone-oxidizing pocket of the cytochrome bc1 (cyt b) enzyme complex, was initially very effective in controlling GSB. However, resistance to AZO has been observed in D. bryoniae in many watermelon-producing regions. In this study, the DNA sequences of partial cyt b genes of four AZO-resistant (AZO-R) and four AZO-sensitive (AZO-S) isolates of D. bryoniae confirmed the amino acid substitution of glycine by alanine at the 143 codon (G143A) in the AZO-R isolates tested. Allele-specific primers were designed to detect the resistant or sensitive allele at codon 143 of the cyt b gene, which amplified a 165-bp polymerase chain reaction (PCR) product from genomic DNA of nine AZO-R and nine AZO-S isolates of D. bryoniae, respectively. The primer pairs did not amplify DNA from other pathogens tested in the study. The results indicated that the PCR assays developed in the study were specific in differentiating AZO-R and AZO-S isolates and could facilitate AZO resistance detection in D. bryoniae.

Azoxystrobin causes oxidative stress and DNA damage in the aquatic macrophyte Myriophyllum quitense.

Among the search for new types of pesticides, the fungicide azoxystrobin (AZX) was the first patent of the strobilurin compounds, entering in the market in 1996. Its use worldwide is growing, mainly linked to soybean production, although its effects in non-target organisms are almost unknown. The goal of the present work was to evaluate effects of short-term AZX exposure to the aquatic macrophyte Myriophyllum quitense, focusing on oxidative stress parameters and DNA fragmentation. Significant inhibition of the antioxidant enzyme systems were observed at 50μg/L AZX for catalase and peroxidase (p<0.05). Lipid and DNA damage were significant at 50 and 100μg/L AZX. These biomarkers were sensitive to AZX and can be used in a battery to evaluate the occurrence of AZX in freshwater ecosystems.

The use of IT in relationship banking

Relationship banking is treated as one of the most important factors determining finance accessibility, especially in case of small and medium-sized businesses. The paper focuses on theoretical and methodological reasoning of changes in relationship banking in light of changing economic conditions and use of IT as communication channel. Thus the problem researched is twofold: the scope and importance of soft information valuation and acceptability of communication channels in developing banking relationships. As the result, the conception of relationship banking maintenance was developed with valuation of business perceptions to IT usage, trust, partnership level and satisfaction with relationships from one side and, from other side, valuation of finance institution's use of IT, policy, standards and conditions applied for maintaining relationships.

Azoxystrobin, butralin, and flumetralin residues in flue-cured tobacco

As part of a continuous effort at North Carolina State University, research was conducted from 2007–2009 to establish the maximum expected pesticide residue on flue-cured tobacco that would result from a maximum labeled application rate and minimum preharvest interval of specific crop protection agents (CPAs). Residues of azoxystrobin, butralin, and flumetralin were measured on flue-cured tobacco over 6 environments in North Carolina during the research cycle. Butralin and flumetralin were applied via broadcast (BC) and downstalk (DS) application. Treatments were applied to tobacco grown on research stations near Clayton and Kinston, NC. Tobacco was managed according to NC Cooperative Extension Service recommendations and harvested 4 times by stalk position. Residues on cured leaf were quantified by Global Laboratory Services, Inc., in Wilson, NC. Data were analyzed and reported by individual year, location, CPA, and stalk position; with primings 1 and 2 represented in the lower stalk position, priming 3 ...

QoI-Resistance Stability in Relation to Pathogenic and Saprophytic Fitness Components of Alternaria alternata from Citrus

The phenotypic stability, fitness components, and ability to cause disease of isolates of the Alternaria alternata tangerine pathotype resistant to quinone-outside inhibitors (QoIs) were studied. Stability of resistance to azoxystrobin (AZ) and pyraclostrobin (PYR) was determined after consecutive transfers on potato dextrose agar (PDA). The sensitivity to QoIs did not change significantly after 10 transfers on PDA compared with the initial sensitivity of all isolates tested. Fitness components evaluated in vitro were mycelial growth, conidial germination, and conidial production. Incubation period, number of lesions per leaf area, and virulence were determined with detached leaf assays using four cultivars: Dancy, Minneola, Murcott, and Sunburst. Variability in fitness components was observed among isolates within the same sensitivity group. As a group, no significant differences in the mean values of these fitness components were observed between resistant and sensitive phenotypes, except for virulence. Resistant isolates were significantly (P < 0.05) more virulent than the sensitive isolates on Dancy, Minneola, and Sunburst but not on Murcott (P = 0.3506). There was no significant correlation between individual fitness components and the level of sensitivity to AZ and PYR. Preventive applications of Abound (commercial formulation of AZ) at full field rates failed to control disease caused by QoI-resistant isolates under greenhouse conditions. Our results suggest that QoI resistance in A. alternata tangerine pathotype is stable in the absence of QoI selection pressure and that resistance development did not affect the fitness of resistant isolates.

Fungicide sensitivity of Mycosphaerella graminicola Tunisian isolates: the importance of drug transporter genes in the process of fungicide tolerance

Seventeen Mycosphaerella graminicola isolates from Tunisia and two reference isolates from Europe (St-Q7-2 and IPO323) were examined for sensitivity to azoxystrobin and tebuconazole and for the importance of the drug transporter genes MgAtr3 (ABC transporter), MgMfs1 (MFS transporter), MgSlt2 (MAP Kinase), MgGpa1 and MgGpb1 (cyclic AMP) in the process of fungicide tolerance. All Tunisian isolates were sensitive to both fungicides, but considerable variability in sensitivity, and evidence for slight multidrug resistance toward both fungicides (r = 0.58), were observed. A gene expression assay revealed that MgAtr3 and MgMfs1 are involved in tolerance to both fungicides. MgAtr3 is likely involved in tolerance to tebuconazole, while MgMfs1 is likely required for tolerance to azoxystrobin. The other genes examined were found more likely to be pathogenicity factors rather than fungicide tolerance factors, except for MgSlt2 which was weakly induced by azoxystrobin treatment. This study has indicated that the Tunisian population of M. graminicola remains more sensitive to strobilurin and azole fungicides than European populations, and reports the importance of the ABC and MFS transporters MgAtr3 and MgMfs1 in the mechanism of fungicide tolerance.

Managing Phytophthora crown and root rot on tomato by pre-plant treatments with biocontrol agents, resistance inducers, organic and mineral fertilizers under nursery conditions

Five trials were carried out under greenhouse conditions to test the efficacy of spray programmes based on biocontrol agents, phosphite-based fertilizers and a chemical inducer of resistance (acibenzolar-S-methyl, phosethyl-Al) to control crown and root rot of tomato incited by Phytophthora nicotianae . The best disease control, under high disease pressure resulting from artificial inoculation, was obtained with three pre-plant leaf sprays at 7 d intervals with acibenzolar-S-methyl and with two mineral phosphite-based fertilizers. The disease reduction achieved was similar to that obtained with a single application of azoxystrobin and metalaxyl-M. Phosetyl-Al and the biocontrol agents Glomus spp. + Bacillus megaterium + Trichoderma , B. subtilis QST713, B. velezensis IT45 and the mixture T. asperellum ICC012 + T. gamsii ICC080 provided a partial disease control. Brassica carinata pellets did not control the disease.

Azoxystrobin, a mitochondrial complex III Qo site inhibitor, exerts beneficial metabolic effects in vivo and in vitro

BackgroundSeveral anti-diabetes drugs exert beneficial effects against metabolic syndrome by inhibiting mitochondrial function. Although much progress has been made toward understanding the role of mitochondrial function inhibitors in treating metabolic diseases, the potential effects of these inhibitors on mitochondrial respiratory chain complex III remain unclear. MethodsWe investigated the metabolic effects of azoxystrobin (AZOX), a Qo inhibitor of complex III, in a high-fat diet-fed mouse model with insulin resistance in order to elucidate the mechanism by which AZOX improves glucose and lipid metabolism at the metabolic cellular level. ResultsAcute administration of AZOX in mice increased the respiratory exchange ratio. Chronic treatment with AZOX reduced body weight and significantly improved glucose tolerance and insulin sensitivity in high-fat diet-fed mice. AZOX treatment resulted in decreased triacylglycerol accumulation and down-regulated the expression of genes involved in liver lipogenesis. AZOX increased glucose uptake in L6 myotubes and 3T3-L1 adipocytes and inhibited de novo lipogenesis in HepG2 cells. The findings indicate that AZOX-mediated alterations to lipid and glucose metabolism may depend on AMP-activated protein kinase (AMPK) signaling. ConclusionsAZOX, a Qo inhibitor of mitochondrial respiratory complex III, exerts whole-body beneficial effects on the regulation of glucose and lipid homeostasis in high-fat diet-fed mice. General significanceThese findings provide evidence that a Qo inhibitor of mitochondrial respiratory complex III could represent a novel approach for the treatment of obesity.