Mitochondrial and Proteasome Dysfunction Occurs in the Hearts of Mice Treated with Triazine Herbicide Prometryn.

Prometryn is a methylthio-s-triazine herbicide used to control the growth of annual broadleaf and grass weeds in many cultivated plants. Significant traces of prometryn are documented in the environment, mainly in waters, soil, and plants used for human and domestic consumption. Previous studies have shown that triazine herbicides have carcinogenic potential in humans. However, there is limited information about the effects of prometryn on the cardiac system in the literature, or the mechanisms and signaling pathways underlying any potential cytotoxic effects are not known. It is important to understand the possible effects of exogenous compounds such as prometryn on the heart. To determine the mechanisms and signaling pathways affected by prometryn (185 mg/kg every 48 h for seven days), we performed proteomic profiling of male mice heart with quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) using ten-plex tandem mass tag (TMT) labeling. The data suggest that several major pathways, including energy metabolism, protein degradation, fatty acid metabolism, calcium signaling, and antioxidant defense system were altered in the hearts of prometryn-treated mice. Proteasome and immunoproteasome activity assays and expression levels showed proteasome dysfunction in the hearts of prometryn-treated mice. The results suggest that prometryn induced changes in mitochondrial function and various signaling pathways within the heart, particularly affecting stress-related responses.

Design, synthesis and mechanism research of novel algicide based on bioactive fragments synthesis strategy.

The frequency and intensity of harmful cyanobacterial blooms (HCBs) are increasing all over the world, their prevention and control have become a great challenge. In this paper, a series of 1,3,4-thiadiazole thioacetamides (T series) were designed and synthesized as potential algaecides. Among them, the compound T3 showed its best algacidal activity against Synechocystis sp. PCC 6803 (PCC 6803, EC50 = 1.51 µM) and Microcystis aeruginosa FACHB 905 (FACHB905, EC50 = 4.88 µM), which was more effective than the lead compound L1 (PCC6803, EC50 = 7.7 µM; FACHB905, EC50 = 8.8 µM) and the commercially available herbicide prometryn (PCC6803, EC50 = 4.64 µM；FACHB905, EC50 = 6.52 µM). Meanwhile, T3 showed a lower inhibitory activity (EC50 = 12.76 µM) than prometryn (EC50 = 7.98 µM) to Chlorella FACHB1227, indicating that T3 had selective inhibition to prokaryotic algae (PCC6803, FACHB905) and eukaryotic algae (FACHB1227). Furthermore, the algacidal and anti-algae activities of T3 were significantly better than those of prometryn, while the toxicity of zebrafish and human cells was less than prometryn. Electron microscope, physiological, biochemical and metabonomic analysis showed that T3 interfered with light absorption and light conversion during photosynthesis by significantly reducing chlorophyll content, thus inhibited metabolic pathways such as the Calvin cycle and TCA cycle, and eventually led to the cell rupture of cyanobacteria. These results afforded further development of effective and safe algaecides.

Herbicide prometryn adversely affects the development and reproduction of Tigriopus japonicus by disturbing the ecdysone signal pathway and chitin metabolic pathway.

Prometryn, a widely used triazine herbicide in agriculture and aquaculture, has been commonly detected in marine environments, but its effects on the marine copepod are unknown. In this study, marine copepod Tigriopus japonicus was chronically exposed to environmentally relevant concentrations of prometryn to investigate its impacts and potential mechanism of action. The results showed that 0.5, 5, and 50 µg/L prometryn delayed the first spawning time and hatching time, reduced the fecundity, and inhibited the population growth rate. Moreover, exposure to 0.5, 5 and 50 µg/L prometryn decreased food ingestion, the content of C and N elements, nutrient accumulation and body size, but increased the content of 20-hydroxyecdysone (20E). Transcriptome analysis showed that 50 µg/L prometryn down-regulated 1431 genes, which were mainly enriched in lysosome pathway and chitin binding and cuticle construction process. The results of qRT-PCR showed that the expression of key genes involved in juvenile hormone synthesis and chitin metabolic pathways were also inhibited after prometryn exposure. Molecular docking revealed that prometryn could bind to ecdysone receptor (EcR) and UDP-N-acetylglucosamine pyrophosphorylase (UAP), components of the ecdysteroid nuclear receptor complex. Therefore, environmental relevant prometryn delayed the molting and development of T. japonicus by disrupting the ecdysone signal pathway and chitin metabolic pathway through binding to EcR and UAP. This study provides new insights into toxic effects and molecular mechanisms of prometryn on marine copepods.

Developmental toxicity of prometryn induces mitochondrial dysfunction, oxidative stress, and failure of organogenesis in zebrafish (Danio rerio).

Prometryn, 2-methylthio-4,6-bis(isopropylamino)-1,3,5-triazine, is a selective thiomethyl triazine herbicide widely used to control unwanted weeds and harmful insects by inhibiting electron transport in target organisms. Despite having various advantages, herbicides pose as a major threat to the environment and human health due to persistent contamination, bioaccumulation, and damage to non-target organisms. In this study, the developmental toxicity of 5, 10, and 20 mg/L prometryn in zebrafish (Danio rerio) embryos was evaluated and compared to that of the solvent control for 96 h. Several transgenic zebrafish models (fli1a:eGFP, flk1:eGFP, olig2:dsRed and L-fabp:dsRed) were visually assessed to detect fluorescently tagged genes. Results showed that prometryn shortened body length, and induced yolk sac, heart edema, abnormal heart rate, and loss of viability. Fluorescence microscopy revealed that prometryn exposure caused defects in organ development, reactive oxygen species accumulation, and apoptotic cell death. Mitochondrial bioenergetics were also evaluated to determine the effect of prometryn on the electron transport chain activity and metabolic alterations. Prometryn was found to interfere with mitochondrial function, ultimately inhibiting energy metabolism and embryonic development. Collectively, our findings suggest that prometryn is a potential contaminate for non-target sites and organisms, especially aquatic, and emphasize the need to consider the toxic effects of prometryn.

Phaseolus vulgaris L. Seedlings Exposed to Prometryn Herbicide Contaminated Soil Trigger an Oxidative Stress Response.

Herbicides from the family of S-triazines, such as prometryn, have been widely used in crop production and can constitute an environmental pollution in both water and soil. As a valuable crop, the common bean (Phaseolus vulgaris L.) is grown all over the world and could be exposed to such herbicides. We wanted to investigate the possible stress sustained by the common bean growing in prometryn-polluted soil. Two situations were observed: when soil was treated with ≥100 µM prometryn, some, but not all, measured growth parameters were affected in a dose-dependent manner. Growth was reduced, and photosynthetic pigments and photosynthetic products were less accumulated when soil was treated with ≥100 µM prometryn. Reactive oxygen species (ROS) produced had a deleterious effect, as seen by the accumulation of oxidized lipid in the form of malondialdehyde (MDA). Higher prometryn (500 µM) concentrations had a disastrous effect, reducing antioxidant activities. At a low (10 µM) concentration, prometryn increased antioxidant enzymatic activities without affecting plant growth or MDA production. Gene expression of proline metabolism genes and proline accumulation confirm that bean plants respond to a stress according to the prometryn concentration. Physiological responses such as antioxidative enzymes APX, CAT, and the enzyme implicated in the metabolization of xenobiotics, GST, were increased at 10 and 100 µM, which indicated a prevention of deleterious effects of prometryn, suggesting that bean is a suitable material both for herbicide pollution sensing and as a crop on a low level of herbicide pollution.

Effect of chronic exposure to prometryne on oxidative stress and antioxidant response in red swamp crayfish (Procambarus clarkii).

The aim of the study was to investigate effects of the triazine herbicide prometryne on red swamp crayfish on the basis of oxidative stress, antioxidant indices in hepatopancreas and muscle, and histopathology of hepatopancreas. Crayfish were exposed to prometryne concentrations of 0.51 µ g L(-1), 0.144 mg L(-1), and 1.144 mg L(-1) for 11 and 25 days. Indices of oxidative stress (thiobarbituric acid reactive substances (TBARS)), and antioxidant parameters (superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR)) in crayfish muscle and hepatopancreas were measured. Chronic exposure to prometryne did not showed the impact of oxidative damage to cells. Changes activity of the antioxidant enzymes SOD, CAT, and GR were observed in all tested concentrations to prometryne for 11 and 25 days (P < 0.01) as compared with the control group. We did not see any differences in histopatological examination to hepatopancreas. Prolonged exposure of prometryne did not result in oxidative damage to cell lipids and proteins, but it led to changes in antioxidant activity in crayfish tissues. Changes in antioxidant systems were also observed in the environmental prometryne concentration of 0.51 µ g L(-1). The results suggest that antioxidant responses may have potential as biomarkers for monitoring residual triazine herbicides in aquatic environments.

Effects of gibberellic acid and N, N-dimethyl piperidinium chloride on the dose of and physiological responses to prometryn in black nightshade (Solanum nigrum L.).

The use of gibberellic acid (GA3) and N, N-dimethyl piperidinium chloride (DPC) in combination with prometryn would likely increase the control of black nightshade in cotton fields. Experiments were designed to investigate the physiological and biochemical responses of black nightshade at the three- to four-leaf stage to prometryn applied at different rates, either alone or in combination with GA3 or DPC, in a greenhouse environment. These studies demonstrated that prometryn applied in combination with DPC at low rates (7.2 g ai ha(-1)) led to increased fresh weight and visible injury of black nightshade compared with prometryn applied alone or in combination with GA3; however, at rates of 36, 180, and 900 g ai ha(-1), prometryn in combination with DPC caused the least visible injury among all treatments and prometryn in combination with GA3 caused the greatest visible injury. These results suggest that black nightshade suffered more severe damage when prometryn was applied in combination with GA3, which is supported by the reduced soluble protein content, lower antioxidant enzyme activities, and higher malondialdehyde (MDA) content in the plants treated with prometryn plus GA3. These results indicate that the application of GA3 in combination with prometryn to black nightshade may have the potential to lower the levels of prometryn tolerance in these plants.

Effect of chronic exposure to prometryne on oxidative stress and antioxidant response in common carp (Cyprinus carpio L.).

The effects of the triazine herbicide prometryne, commonly present in surface and ground waters, on oxidative stress and antioxidant status of common carp (Cyprinus carpio) were investigated. Fish were exposed to sublethal concentrations of prometryne (0.51, 8, and 80µg/l) for 14, 30, and 60 days. Activity of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), as well as levels of thiobarbituric acid reactive substances (TBARSs) were assessed in brain, gill, intestine, liver, and muscle. After 14 days exposure, decreased GR activity in brain was observed for all prometryne-exposed groups compared with the controls. Changes were observed in SOD activity in brain and gill after 30 days in all exposure groups. Changes in CAT activity were observed only at the highest concentration (80µg/l) in liver and intestine after 60 days. The observed effects on carp antioxidant systems may be a defense against oxidative damage. The study demonstrated changes in antioxidant parameters and the importance of evaluating the potential long-term risk to fish of prometryne, at environmentally realistic concentrations (0.51µg/l). The results suggest that antioxidant responses may have potential as biomarkers for monitoring residual triazine herbicides in aquatic environments.

Use of biometric, hematologic, and plasma biochemical variables, and histopathology to assess the chronic effects of the herbicide prometryn on Common Carp.

BACKGROUND: Effects of acute and subchronic exposure of fish to s-triazine herbicides have been well documented, but data on the effects of prometryn on blood analytes in carp at environmentally realistic concentrations are lacking. OBJECTIVE: The objective of the study was to determine whether biometrics, blood analytes, and histopathology could serve as bioindicators in fish living in waters polluted by triazine. METHODS: Fish were exposed to prometryn at concentrations of 0.51 (reported concentration in Czech rivers), 8.0, and 80 µg/L for 14, 30, and 60 days. Prior to and during this period, biometrics, blood analytes, and histopathology were evaluated. RESULTS: After 60 days' exposure to 8.0 and 80 µg/L of prometryn, spleen weights (P < .05) and lactate (P < .01) levels were significantly lower, and concentrations of HGB (P < .01) and MHC (P < .01) and MCHC (P < .01) were higher, relative to controls. After 30 and 60 days' exposure to 0.51, 8.0, and 80 µg/L of prometryn, AST activity, calcium, magnesium, and inorganic phosphate levels were lower (P < .01), while creatinine concentration and ALT activity were higher (P < .01) than in controls. Glucose was higher after exposure to 80 µg/L after 30 and 60 days, and after 60 days' exposure to 8.0 µg/L. Renal histology revealed severe hyaline degeneration of the epithelial cells of caudal kidney tubules in fish at all exposure levels. CONCLUSIONS: This study shows effects in fish blood at a concentration of 0.51 µg/L of prometryn, a significant finding in view of prometryn reaching a maximum of 4.4 µg/L or less in European rivers. Select blood analytes, such as creatinine, and histologic changes in caudal kidney are potential biomarkers for monitoring residual triazine pesticides in Common Carp.

Effects of prometryn and acetochlor on arbuscular mycorrhizal fungi and symbiotic system.

UNLABELLED: Prometryn and acetochlor are common herbicides widely used to control weeds in agricultural systems. The impacts of the two herbicides on spore germination, hyphal elongation, the biomass and malondialdehyde content of carrot hairy roots were investigated using a strict in vitro cultivation system associating the Ri T-DNA-transferred carrot hairy roots with Glomus etunicatum. Alternatively, root colonization, daughter spore production and the proportion of hyphae with succinate dehydrogenase (SDH) and alkaline phosphatase (ALP) activities were also investigated. No significant impact on spore germination was noted in the presence of acetochlor at all three concentrations tested, while a significant decrease was observed with prometryn only at the highest concentration. Moreover, an inverse correlation was identified between herbicides concentrations and G. etunicatum root colonization and spore production as well as hyphal SDH and ALP activity, with a positive correlation identified among these four factors. Both herbicides exerted negative effects on the arbuscular mycorrhizal (AM) fungus and symbiosis at increasing concentrations, with prometryn apparently more toxic than acetochlor. Furthermore, the AM symbiotic system was shown to improve biomass, reduce malondialdehyde accumulation and ease lipid peroxidation in carrot hairy roots and decrease damage in host plants, thus enhancing plant tolerance to adverse conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, the effect of prometryn and acetochlor on the physiology and metabolic activities of the AM fungus Glomus etunicatum were investigated. Our findings demonstrate for the first time, the impact of the two herbicides at three concentrations (0.1, 1 and 10 mg l(-1)) on transformed carrot hairy roots/AM fungus association under strict in vitro culture conditions, which may guide the application of the two herbicides in modern agriculture.

Influence of benomyl and prometryn on the soil microbial activities and community structures in pasture grasslands of Slovakia.

The effects of pesticides (a herbicide and a fungicide) on the microbial community structure and their activity were analyzed in soil from four alpine pasture grasslands in Slovakia. Specifically, the effects of the herbicide, Gesagard (prometryn active ingredient), and fungicide, Fundazol 50 WP (benomyl active ingredient), on the microbial respiration activity (CO2 production), the numbers of selective microbial physiological groups (CFU.g(-1)) and the structure (relative abundance) of soil microbial communities [(phospholipid fatty acid (PLFA)] were analyzed under controlled laboratory conditions. All treatments including the treatments with pesticides increased (statistically significantly) the production of CO2 in all fields during 21 days of incubation and posed a statistically insignificant negative influence on the numbers of the observed physiological groups of microorganisms. The significantly negative influence was evaluated only in the numbers of two physiological groups; spores of bacteria utilizing organic nitrogen and bacteria, and their spores utilizing inorganic nitrogen. A shift in the microbial composition was evident when the PLFA patterns of samples from different sites and treatments were compared by the Principal Component Analysis (PCA). According to the second component PCA 2 (15.95 %) the locations were grouped into two clusters. The first one involved the Donovaly and Dubakovo sites and the second one contained the Velka Fatra and Mala Fatra locations. The PLFA composition of the soils showed important changes after the treatment with pesticides according to PCA 1 (66.06 %). Other treatments had not had a significant effect on the soil microbial community with the exception of the population of fungi. The lower relative abundance (significant effect) of Gram-positive bacteria, actinomycetes and general group of bacteria were determined in samples treated by the herbicide Gesagard. The application of fungicide Fundazol decreased (statistically significantly) the relative abundance of actinomycetes and general group of bacteria and paradoxically increased the population of fungi.

Determination of resistant biotypes of Amaranthus retroflexus L. on triazines.

Considering the fact that since 1966 in our country the mostly produced have been triazine herbicides on the bases of ametryn, simazine, atrazine and prometryn, we have studied resistance of Amaranthus retroflexus from different sites in regard to the above mentioned herbicides. Seed of weed species for which exist-possibility of resistance have been collected from different localities in Vojvodina, such as Backa Palanka, Backi Maglic and Becej. Studies were performed during 1999 and 2000 by whole plant studies (Thurnwachter, 1998) and by petri dish assays (Clay, Underwood, 1989). Plants were treated by range of atrazine rates (Atrazin S-50) including also susceptible, referent population. Results indicate atrazine resistance of Amaranthus retroflexus at Backa Palanka and Backi Maglic sites, which have been treated by triazine herbicides in many years lasting period.

Effect of pesticides on oestradiol-receptor complex formation in rat uterus cytosol.

The effect of gamma-1,2,3,4,5,6-hexachlorocyclohexane (lindane), 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) and 2-methylthio-4,6-bis-isopropylamino-s-triazine (prometryne) on the formation of a specific oestradiol-receptor complex in the rat uterus cytosol has been examined in vitro and in vivo. Both in vitro and in vivo, the pesticides significantly (P < 0.001) inhibited the formation of the complex in the rat uterus cytosol. The decrease in the number of free specific binding sites on the receptors was determined. The affinity of binding was not modified under the influence of pesticides, and the Kd value was of the same order of magnitude (10(-9) M). The inhibition was found to be fully non-competitive.

Studies on the action of pesticides upon the endocrines using in vitro human thyroid cells culture and in vivo animal models. II. Herbicides-prometrin and terbutrin.

The effects of prometrin and terbutrin in doses of 0.001--1 mg/1.5 ml culture medium on human thyroid cell cultures were studied following up their influence on cell multipliction, proteic synthesis, enzymatic activity of thyroid cells and hormonal synthesis. The results differed in relation to the dose and the type of thyroid cell under study. The acute experiment performed on rats treated with 50 ppm/prometrin or terbutrin/kg b.w. for 15 days revealed variations in T3, T4 and LH synthesis. Both prometrin and terbutrin stimulate T3 synthesis and inhibit T4 synthesis. LH synthesis appears much increased in the hypophysis of the rats treated with terbutrin, whereas the amount of LH released into the serum is much decreased as compared to the controls.

Effects of the herbicides fluometuron and prometryn of Rhizoctonia solani in soil cultures.

Responses of Rhizoctonia solani to herbicides in soil cultures were assessed by measuring soil enzyme activity and other growth-related factors. Both beta-galactosidase (EC 3.2.1.23) and phosphatase (EC 3.1.3.1.3.1.3.2) activities were highly correlated with amounts of mycelium in soil. Both enzyme activities were reduced significantly by either fluometuron or prometryn at 40 microgram/g of soil; the pathogen was more distinctly suppressed by fluometron and showed a stronger tendency to overcome the effects of prometryn with time. Inhibition was also reflected in reduced ultilization of glucose and less CO2-C evolved. Except for an increase in beta-galactosidase activity in the presence of 1 microgram fluometuron, low levels of either herbicide had little effect on the pathogen.