Impact of Iron Formulations on Topramezone Injury to Bermudagrass

Goosegrass control options in bermudagrass are limited. Topramezone is one option that offers excellent control of mature goosegrass, but application to bermudagrass results in unacceptable symptoms of bleaching and necrosis typical of HPPD inhibitors. Previous research has shown that adding chelated iron reduced the phytotoxicity of topramezone without reducing the efficacy of the herbicide resulting in safening when applied to bermudagrass. Our objective was to examine additional iron sources to determine if similar safening effects occur with other sources. Field trials were conducted in the summers of 2016 - 2018 (Auburn University). Mixtures of topramezone and MSO were combined with 6 different commercial iron sources, including FeEDDHA, FeDTPA, iron citrate, FeSO4, and a combination of iron oxide/sucrate/sulfate, some of which contained nitrogen. Bermudagrass necrosis and bleaching symptoms were visually rated on a 0 to 100% scale. Reflectance (NDVI) and clipping yield measurements were also collected. Application of FeDTPA and FeSO4 reduced symptoms of bleaching and necrosis when applied with topramezone. Other treatments which contained nitrogen did not reduce injury but did reduce bermudagrass recovery time following the appearance of necrosis. Inclusion of small amounts of nitrogen often negated the safening effects of FeSO4. The iron oxide/sucrate/sulfate product had no effect on bleaching or necrosis. Data suggests that iron source had a differential effect on bleaching and necrosis reduction when applied in combination with topramezone to bermudagrass. Overall, FeSO4 and FeDTPA safened the topramezone the most on bermudagrass.

Antioxidant Activity In vivo and Ex Vivo of Tautomeric Pair of Polyprenylated Benzophenone - Garcinielliptone FC (Platonia insignis Mart Seeds)

Background: Garcinielliptone FC corresponds to a polyprenylated acylphloroglucinol having a benzophenonic core (diphenylmethanone) substituted with isoprenyl(s) group(s) (3-methyl-2-butenyl) and 2-isopropenyl-hex-5-enyl. Objective: The present work evaluated the antioxidant activity of garcinielliptone FC (GFC) in vitro against non-biological radicals [2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS•+)] and ex vivo against oxidative damage induced by AAPH (2,2'-azobis-2-methylpropionamidine dihydrochloride) and iron/citrate ion in erythrocytes and mitochondria, respectively. Methods: In addition to the protective effect, the main biochemical indexes of oxidative stress, such as lipid peroxidation through the formation of Thiobarbituric Acid Reactive Substances (TBARS), Superoxide Dismutase (SOD), Catalase (CAT) activity and reduced glutathione (GSH) levels. Results: According to the results obtained in erythrocytes, the antioxidant results at concentrations of 0.1, 0.3, 0.7, 1.5 and 3.0 mM were 26.34 ± 0.68, 43.39 ± 2.17, 62.27 ± 2.17, 86.69 ± 0.47 and 92.89 ± 0.45%, respectively, where GFC reduced the rate of oxidative hemolysis when compared to AAPH (p<0.05). The antioxidant activity observed in erythrocytes was also seen in mitochondria in which GFC reduced mitochondrial swelling by increasing the absorbance when compared to iron/citrate ion complex (p<0.05). In both biological models, GFC had an antioxidant effect on erythrocyte and mitochondrial redox balance when analyzing oxidative stress biomarkers, such as reduction of lipid peroxidation and inhibition of depletion in the activity of SOD, CAT and GSH levels. Conclusion: In conclusion, GFC had in vitro and ex vivo antioxidant activity against oxidative damage induced in erythrocytes and mitochondria acting on the erythrocytic and mitochondrial redox balance.

P1387IRON CITRATE BLOCKS THE PROGRESSION OF CALCIUM DEPOSITION BY REVERTING APOPTOSIS AND AUTOPHAGY IN VSMCS

Background and Aims Cardiovascular disease is the first cause of mortality in chronic kidney disease (CKD) induced by vascular calcification. Since, in advanced CKD, iron based phosphate binders have been proposed to treat hyperphosphatemia, we studied, in high-phosphate (Pi) calcified VSMC, the effect of iron citrate (iron) on the progression of calcium deposition. Method We treated VSMCs with 5 mM Pi and iron citrate to evaluate Ca deposition by Alizarin Red destaining, DNA fragmentation by ELISA, gene expression by RT-PCR and protein expression by Western blot. Results High-Pi calcification was blocked when iron was added from day 7 to 15 (1.30±0.03vs0.61±0.02; OD/mg protein; day 15; PivsPi+Fe, p&lt;0.01). Since iron added prophylactically prevented apoptosis and potentiated autophagy we studied the role of these two processes in the therapeutic protocol. Adding iron from day 7 to day 11 decreased apoptotic cell number (17.3±2.6vs11.6±1.6; Annexin V; % positive cells; day 11; PivsPi+Fe; p&lt;0.05, figure). To confirm the effect of iron on apoptosis, we demonstrated its action in blocking the H2O2-induced increase in calcification when added from day 7 to day 14 (1.37±0.03 vs. 0.96±0.05; H2O2+Pi day 7-14 vs Fe+H2O2+Pi day 7-14; day 14; OD/mg protein; p&lt;0.01). We then investigated the mechanism of the anti-apoptotic effect by studying the pro-survival axis GAS6/AXL, finding that iron treatment from day 9 to day 14 counteracted the protein down-regulation, and induced their de-novo synthesis. Supporting the effect of therapeutic added iron on apoptosis we found a decrease in apoptotic nuclei both in VSMCs and aortic rings after iron treatment from day 7 to 15 (3.8±0.2vs2.3±0.3 and 4.0±0.3vs2.2±0.2; apoptotic nuclei; arbitrary score; day 15; PivsPi+Fe; VSMCs and aortic rings; p&lt;0.05). Moreover, iron added from day 9 to day 15 potentiated autophagic flux and increased the number of autophagosomes with damaged mitochondria. Conclusion Iron exerts an anti-apoptotic and pro-autophagic effect on established calcified VSMC when simil-osteoblastic transformation was already occurred.

Therapeutic Effect of Iron Citrate in Blocking Calcium Deposition in High Pi-Calcified VSMC: Role of Autophagy and Apoptosis

In chronic kidney disease (CKD), the first cause of mortality is cardiovascular disease induced mainly by vascular calcification (VC). Recently, iron-based phosphate binders have been proposed in advanced CKD to treat hyperphosphatemia. We studied the effect of iron citrate (iron) on the progression of calcification in high-phosphate (Pi) calcified VSMC. Iron arrested further calcification when added on days 7–15 in the presence of high Pi (1.30 ± 0.03 vs 0.61 ± 0.02; OD/mg protein; day 15; Pi vs Pi + Fe, p < 0.01). We next investigated apoptosis and autophagy. Adding iron to high-Pi-treated VSMC, on days 7–11, decreased apoptotic cell number (17.3 ± 2.6 vs 11.6 ± 1.6; Annexin V; % positive cells; day 11; Pi vs Pi + Fe; p < 0.05). The result was confirmed thorough analysis of apoptotic nuclei both in VSMCs and aortic rings treated on days 7–15 (3.8 ± 0.2 vs 2.3 ± 0.3 and 4.0 ± 0.3 vs 2.2 ± 0.2; apoptotic nuclei; arbitrary score; day 15; Pi vs Pi + Fe; VSMCs and aortic rings; p < 0.05). Studying the prosurvival axis GAS6/AXL, we found that iron treatment on days 9–14 counteracted protein high-Pi-stimulated down-regulation and induced its de novo synthesis. Moreover, iron added on days 9–15 potentiated autophagy, as detected by an increased number of autophagosomes with damaged mitochondria and an increase in autophagic flux. Highlighting the effect of iron on apoptosis, we demonstrated its action in blocking the H2O2-induced increase in calcification added both before high Pi treatment and when the calcification was already exacerbated. In conclusion, we demonstrate that iron arrests further high Pi-induced calcium deposition through an anti-apoptotic action and the induction of autophagy on established calcified VSMC.