Hoda M. Nasr

Antioxidant effect of selenium on lipid peroxidation, hyperlipidemia and biochemical parameters in rats exposed to diazinon

Diazinon (DZN) is one of the most organophosphate insecticides that widely used in agriculture and industry. Selenium is generally recognized to be a trace mineral of great importance for human health, protecting the cells from the harmful effects of free radicals. Therefore, the present study was carried out to investigate the alterations in biochemical parameters, free radicals and enzyme activities induced by diazinon in male rat serum, and the role of selenium in alleviating the negative effects of DZN. Animals were divided into four groups of seven rats each; the first group was used as control. Groups 2, 3 and 4 were treated with selenium (Se; 200μg/kg BW), diazinon (DZN; 10mg/kg BW) and diazinon plus selenium, respectively. Rats were orally administered their respective doses daily for 30 days. Results obtained showed that DZN significantly induced thiobarbituric acid reactive substances (TBARS) and decreased the activities of glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) and the levels of reduced glutathione (GSH) in rat sera. Aminotransferases (AST, ALT), phosphatases (AlP, AcP) and lactate dehydrogenase (LDH) activities were significantly increased while acetylcholinesterase (AChE) activity was decreased due to DZN administration. Also, DZN treatment caused significant perturbations in lipids profile and serum biochemical parameters. On the other hand, Se alone significantly decreased the levels of TBARS, total lipids, cholesterol, urea and creatinine, while increased the activities of antioxidant enzymes and glutathione content, total protein (TP) and albumin. In addition, Se in combination with DZN partially or totally alleviated its toxic effects on the studied parameters. In conclusion, Se has beneficial effects and could be able to antagonize DZN toxicity.

Selenium modulates β-cyfluthrin-induced liver oxidative toxicity in rats

This study was designed to investigate the possibility of β‐cyfluthrin to induce oxidative stress and biochemical perturbations in rat liver and the role of selenium in alleviating its toxic effects. Male Wister rats were randomly divided into four groups of seven each, group I served as control, group II treated with selenium (200 µg/kg BW), group III received β‐cyfluthrin (15 mg/kg BW, 1/25 LD50), and group IV treated with β‐cyfluthrin plus selenium. Rats were orally administered their respective doses daily for 30 days. The administration of β‐cyfluthrin caused elevation in lipid peroxidation (LPO) and reduction in the activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione S‐transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR). A decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases (AST and ALT) and alkaline phosphatase (ALP) were decreased, whereas lactate dehydrogenase (LDH) was increased. Selenium in β‐cyfluthrin‐induced liver oxidative injury of the rats modulated LPO, CAT, SOD, GSH, GST, GPx, and GR. Also, liver AST, ALT, ALP, and LDH were maintained near normal level due to selenium treatment. It is concluded that selenium scavenges reactive oxygen species and render a protective effect against β‐cyfluthrin toxicity.

Oxidative stress and biochemical perturbations induced by insecticides mixture in rat testes

The joint action of pyrethroids, lambda-cyhalothrin (LC) in combination with organophosphates, fenitrothione (FNT) on antioxidant defense system and lipid peroxidation biomarkers in rat testes was studied. The results suggest that incubation of testes homogenate with different concentrations of insecticide mixture for different time intervals significantly decreased the activity of antioxidant enzymes, like glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT), and the level of reduced glutathione (GSH). In addition, a significant inhibition in transaminases (AST, ALT), phosphatases (AcP, AlP) activity and protein content were observed. On the other hand, FNT plus LC increased the cellular lipid peroxidation (LPO) level and the activity of lactate dehydrogenase (LDH). In conclusion, the use of insecticides mixture might cause marked oxidative damage in a concentration and time-dependent manner.

Determination of Imidacloprid and Tetraconazol Residues in Cucumber Fruits

The experimental design was a complete randomized blocks design with two treatments for imidacloprid and tetraconazole in addition to control. Each treatment includes three replicates. The application was carried out using knapsack sprayer equipped with one nozzle. Its residues on and in cucumber fruits collected after one hour, 1, 3, 5, 8, 11, 15 and 21 days from last spray were lower than the maximum residue limit (MRL) of imidacloprid and tetraconazole on cucumber fruits. The results obtained revealed that the residual level of imidacloprid was less than the maximum residual level (MRL=1 mg/kg) which recommended by Codex Alimentration Commission, and the residual level of tetraconazole was less than the maximum residual level (MRL=0.2 mg/kg) which recommended by Codex Alimentration Commission. Also, the results showed that tetraconazole high persistence (t1/2=1.4 days) than imidacloprid (t1/2=2.2 days) on cucumber fruits.

Toxicity and Biochemical Effect of Organophosphates and Bio-pesticides against Root-knot Nematode, Meloidogyne incognita

This study was carried out to investigate the toxicity and Biochemical effect of two (biopesticides) biofly, abamectin and two organophosphates pesticides cadusafos and fenitrothion against root-knot nematode, Meloidogyne incognita egg filtrates and second stage juveniles (J2) as well as on laboratory experiment, also the inhibitory effect of the tested pesticides to acetylcholenesterase (AChE) and adenosine triphosphatase (ATPase) were determined. Results indicated that the tested pesticides have toxic action against Meloidogyne incognita second-stage juveniles (J2) and egg filtrates after 24 hrs from application to 72 hrs and the toxicity increased with the time. Abamectin was most toxic followed by cadusafos , fenitrothion and biofly was least in its toxicity to M. incognita second stage juveniles (J2 )and egg filtrates while the toxicity are depending on dose. The tested pesticides have inhibitory effect on AChE and ATPase activity and the inhibitory effect increased with AChE in case of abamectin and cadusafos while the potency of the organophosphate pesticides to inhibit ATPase were limited refers to its mode of action.

Effect of Imidacloprid and Tetraconazole on Various Hematological and Biochemical Parameters in Male Albino Rats (Rattus Norvegious)

This study was carried out to investigate the toxicity of imidacloprid and tetraconazole in male rats given daily oral doses of these pesticides (for 30 days). Which equal to those residues found in and on cucumber fruits after zero time, (24 hour after application) as well as two doses which equal 0.1, 0.125 of the LD50 value for each pesticide? These doses were (0.943, 0.365, 45, 56.25 mg/kg) for imidacloprid, and (0.174, 0.104, 124.8, 156 mg/kg) for tetraconazole, respectively.Results indicated that imidacloprid and tetraconazole residues on and in cucumber fruits after one hour and 24 hour from the last spray did not cause any significant effects on the activities of AST, ALT, GGT, LDH and ALP enzymes. There is no significant difference on the levels of creatinine, uric acid, total protein, albumin and glucose in the serum of treated rats. There is no effect on Packed Cell Volume (PCV), Red Blood Cell Counts (RBC’s), haemoglobin (Hb) and White Blood Cell Counts (WBC’s) in the blood of treated rats. Also doses equal to the residues did not cause any harmful effect on concentrations of AChE, T3, T4, TSH and testosterone hormone. The aforementioned results of this part of study indicated that the neonicotinoid insecticide, imidacloprid, and the fungicide tetraconazole, can induce a variety of alterations in the activities of AST, ALT, GGT, LDH and ALP enzymes and the levels of creatinine, uric acid, total protein, albumin and glucose in the serum of treated rats also the concentrations of AChE, T3, T4, TSH and testosterone hormone at higher doses which equal to 0.125 and 0.1of the LD50value for each pesticide. The severity of their action depends entirely on the level of the given doses and the type of the tested pesticides.

Toxicity of naturally occurring Bio-fly and chitosan compounds to control the Mediterranean fruit fly Ceratitis capitata (Wiedemann)

The efficacy of five compounds of a biopolymer chitosan and Bio-fly (Beauveria bassiana fungus) as biopesticide was evaluated on Ceratitis capitata under laboratory conditions. The inhibitory effects on acetylcholinesterase (AChE) and adenosinetriphosphatase (ATPase) as biochemical indicators were also determined in vivo. The results indicated that B. bassiana based Bio-fly exhibited significant toxicity against C. capitata (LC50 = 3008 and 3126 mg/L after 48 h in females and males, respectively) followed by the derivatives of chitosan, N-(4-propylbenzyl)chitosan and N-(2-nitrobenzyl)chitosan. Bio-fly displayed remarkable inhibition of AChE activity (IC50 = 2220 mg/L) while N-(2-chloro,6-flourobenzyl)chitosan, N-(4-propylbenzyl)chitosan and N-(3,4-methylenedioxybenzyl) chitosan had no significant difference in inhibitory action. In adult males, N-(2-nitrobenzyl)chitosan exhibited the highest inhibitory action (IC50 = 6569 mg/L). In addition, the toxic effects of the tested compounds on the activity of ATPase indicated that highly significant inhibition was found with N-(4-propylbenzyl)chitosan with an IC50 of 8194 and 8035 mg/L, in females and males, respectively.

Determination of Imidacloprid and Tetraconazol Residues in Cucumber Plants after whitefly and powdery mildew control.

The present study was carried out to determine the residues of the neonicotinoid insecticide imidacloprid , and the fungicide tetraconazole and their persistence in and on cucumber fruits after whitefly and powdery mildew control .The field experimental design was a complete randomized blocks design with two treatments for imidacloprid and tetraconazole in addition to control (42m 2 ).The application was carried out using knapsack sprayer equipped with one nozzle. Cucumber fruits samples were collected from each replicate (one Kg) at time intervals of one hour after application( zero time), 1 , 3 , 5 , 8 , 11 , 15 and 21 days after treatment with imidacloprid and tetraconazole. Estimation of imidacloprid residues were performed by High pressure liquid chromatography equipped with diode array UV detector .Quantitative analysis of tetraconazole residues were performed by Perkin gas chromatograph (GLC), equipped with electron capture detector (ECD. Result indicated that the recovery percentage of tetraconazole and imidacloprid were 91.62 % and 117.5% respectively. The initial deposit (one hour after application) was 0.943 mg/kg. while the detected residue amounts were 0.365, 0.271, 0.226, 0.086, 0.049, 0.028 and 0.013mg/kg of imidacloprid after 1, 3, 5, 8, 11, 15 and 21days of treatment, respectively. The calculated half life (t1/2) value of this insecticide was 2.2 days. On the other hand the initial deposit of tetraconazole on and in cucumber fruits was 0.1742 mg/kg The obtained residual half-life value (t1/2) of tetraconazole on and in cucumber fruits was 1.4 day. Data also revealed that the first day following application is critical in the sense of sharply decrease that reach 61.29% from the initial deposit of imidacloprid on cucumber fruits, but the loss of tetraconazole at first day was 40.41% from the initial residues on cucumber fruits.