The Protective Effect of Rosewater against DNA Damages and Oxidant and Antioxidant Parameters of Rats Exposed to Chlorpyrifos Ethyl.

OBJECTIVE: The aim of this study was to determine both the protective effect of rose water (RW) against DNA damage in the tissues of rats exposed to chlorpyrifos-ethyl (CPE) and RW's effect on the oxidant and antioxidant levels in the blood serum and brain tissues of those same rats. METHODS: In this experimental study, 32 mature male wistar albino rats were divided into 4 groups: group I, control; group II, CPE; group III, RW; and group IV, CPE+RW. The parameters of DNA tail intensity and DNA tail moment were analysed in blood samples by comet assay. Glutathione S-transferase (GST), catalase (CAT), and malondialdehyde (MDA) levels in brain tissues were examined. In blood serum, the levels of melatonin (MT) from 3-nitrotyrosine (3-NT) were determined. RESULTS: In the CPE+RW group, the MDA and 3-NT levels in the brain tissues were significantly reduced (p<0.001), while the MT, GST, and CAT levels were significantly higher (p<0.001) compared to those of the CPE group. When the control and RW groups were compared, the CAT, GST, and MT levels were significantly higher (p<0.001) in the RW group, while the MDA and 3-NT levels were significantly lower (p<0.001). CONCLUSION: In rats, RW had positive effects on oxidant damage created by CPE. Both the DNA tail intensity and DNA tail moment in the CPE group were significantly higher (P<0.001) compared to those measures for the control group.

Hydrogen sulfide (H2S) releasing agents: chemistry and biological applications.

Hydrogen sulfide (H2S) is a newly recognized signaling molecule with very potent cytoprotective actions. The fields of H2S physiology and pharmacology have been rapidly growing in recent years, but a number of fundamental issues must be addressed to advance our understanding of the biology and clinical potential of H2S in the future. Hydrogen sulfide releasing agents (also known as H2S donors) have been widely used in these fields. These compounds are not only useful research tools, but also potential therapeutic agents. It is therefore important to study the chemistry and pharmacology of exogenous H2S and to be aware of the limitations associated with the choice of donors used to generate H2S in vitro and in vivo. In this review we summarized the developments and limitations of currently available donors including H2S gas, sulfide salts, garlic-derived sulfur compounds, Lawesson's reagent/analogs, 1,2-dithiole-3-thiones, thiol-activated donors, photo-caged donors, and thioamino acids. Some biological applications of these donors were also discussed.

Children's inhalation exposure to methamidophos from sprayed potato fields in Washington State: exploring the use of probabilistic modeling of meteorological data in exposure assessment.

We examined the significance of meteorology and postspray volatilization of methamidophos (an organophosphorus insecticide) in assessing potential inhalation risk to children in an agricultural community. We combined fluxes from sources and dispersion modeling with a range of possible local meteorology to create output to study the variability in potential community exposure as a result of changing temperature, wind speeds and wind directions. This work is based on an aerial spray drift study where air sampling measurements of methamidophos were made before, during and after a spray event were used to examine acute inhalation risk for children living in an Eastern Washington State community in close proximity (between 15 and 200 m) to sprayed potato fields. We compared the measured average air concentrations of methamidophos in the community to a "no observed adverse effect level" for subchronic inhalation to characterize acute and subchronic inhalation risks. The baseline estimates of inhalation exposure were below Environment Protection Agency's (EPA) level of concern based on a target margin of exposure of 300. As meteorological conditions during and after spraying influence the amount of material moving into areas where children reside we used historical meteorological data to drive model simulations that predicted likely air residue concentrations under different wind and temperature conditions. We also added variability to the decay constant and initial emission fluxes to create a 2-D simulation of estimated air concentrations in the community near the fields. This work provides a methodological framework for the assessment of air concentrations of pesticides from agricultural sprays in the absence of extended measurements, although including variability from meteorological conditions. The deterministic as well as the probabilistic risk analyses in this study indicated that postspray volatilization in the specific spray situation analyzed (methamidophos applied on potato fields in Eastern Washington) did not pose acute or subchronic risks as defined by the EPA. However, this study did not consider any pathway of exposure other than inhalation (e.g. diet, dermal, etc.) and the risk assessment should be evaluated in that context.

Pirimiphos-methyl and benalaxyl losses in surface runoff from plots cultivated with potatoes.

Abstract: Losses of pirimiphos-methyl and benalaxyl in runoff water from clay soil plots cultivated with potatoes and of differing soil surface slopes were determined over approximately 120 days (1 October 1999-28 January 2000). The plot slopes were 0, 1, 2.5 and 5%, and soil erosion increased with the slope from 610 to 1760kgha(-1). The runoff of surface water was between 3.1 and 16.6% of the rainfall. Surface runoff was highest for the fifth and seventh runoff events due to rainfall, 51 days and 72 days after the first pesticide application. The maximum concentrations of the two pesticides in runoff occurred in the plots with the greatest slope (5%) during the fifth runoff event, November 21, 1999 reaching 8.4 and 12.3 microg litre(-1) for pirimiphos-methyl and 17.8 and 20.2 microg litre(-1) for benalaxyl in tilled and untilled plots respectively. The cumulative losses of pirimiphos-methyl in surface runoff from tilled and untilled plots with a slope 5% were estimated at only 0.37 and 0.59% of the initial applied active ingredient, respectively, while for plots with a slope 0% the percentages were 0.013 and 0.018%. For benalaxyl the corresponding values from tilled and untilled plots were 1.69 and 1.76% (slope 5%), and 0.062 and 0.085 (slope 0%). Degradation of the pesticides in the topsoil was monitored from October 1999 and May 2000. Cultivation of potatoes decreased the half-life of the two pesticides compared to the untilled fields, for pirimiphos-methyl from 16.7 to 9.2 days and for benalaxyl from 26.7 to 12.6 days. The slope of soil surface and the different sorption capacities for the compounds are the main parameters which influenced the transportation of studied pesticides, pirimiphos-methyl and benalaxyl residues via surface water in soil-water systems.

The efficacy of different decontaminants in rats and pigs percutaneously poisoned with organophosphates.

The efficacies of clay or alcoholate as decontaminants and a polyethylene glycol + oxime N-octylpyridium-4-aldoxime bromide (OPAB) protective ointment were evaluated in rats and pigs percutaneously poisoned with O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate (VX) and soman (GD) nerve gases. The use of protective ointment per se or combined with the decontaminants protected all rats poisoned with GD, regardless of the experimental procedure. No poisoning or fatalities were observed in pigs decontaminated 2 min later with clay or alcoholate, while the protective ointment delayed the onset of poisoning and even prevented death. The application of protective ointment, with or without the use of decontaminants, significantly postponed the onset of poisoning in animals contaminated with VX. There was no significant difference between procedures. Decontamination was very satisfactory and dependent on the duration of exposure, being somewhat more efficient if performed by 30 min after exposure.

Combined modality radioprotection: the use of glucan and selenium with WR-2721.

Glucan, WR-2721, and selenium, three agents with distinct radioprotective mechanisms, were evaluated in C3H/HeN mice for survival-enhancing and hemopoietic-regenerating effects when administered alone or in combinations before exposure to 60Co radiation. At LD50/30 radiation doses (radiation doses lethal for 50% of mice within 30 days postexposure), dose reduction factors of 1.21, 1.02, 1.37, 1.51, and 1.66 were obtained following glucan (75 mg/kg i.v., -20 hr), selenium (0.8 mg/kg, i.p., -20 hr), WR-2721 (200 mg/kg, i.p., -30 min), glucan + WR-2721, and glucan + selenium + WR-2721 treatments, respectively. All treatments increased numbers of hemopoietic stem cells as measured by the day 12 endogenous spleen colony-forming unit (E-CFU) assay; the most significant E-CFU effects, however, were observed following glucan + WR-2721 and glucan + selenium + WR-2721 treatments. Combined modality treatments were also more effective than single-agent treatments at accelerating bone marrow and splenic granulocyte-macrophage colony-forming cell (GM-CFC) regeneration. These results demonstrate the value of multiple-agent radioprotectants.