Yusuf Sevgiler

Effects of diazinon on acetylcholinesterase activity and lipid peroxidation in the brain of Oreochromis niloticus

The aim of this study was to investigate the effects of organophosphorus (OP) pesticide diazinon on acetylcholinesterase (AChE: EC 3.1.1.7) activity and its relationship to lipid peroxidation (LPO) in the brain of a freshwater fish, Oreochromis niloticus. Malondialdehyde (MDA) content was used as biomarker for LPO. Fish were exposed to 1 and 2mg/L sublethal concentrations of diazinon for 1, 7, 15 and 30 days. In the entire experimental group, AChE activity in brain significantly decreased (up to 93% of control), whereas MDA content decreased after 1 day, and increased after 7 and 15 days of exposures. MDA was in similar level with the control group after diazinon exposure of 30 days. The findings of the present study show that diazinon inhibited AChE activity and it has LPO-inducing potential in fish. The inhibition of AChE activity in the brain of O. niloticus correlated with increased MDA levels after 7 and 15 days diazinon exposures (r=-0.661, P<0.019; r=-0.652, P<0.022, respectively).

Antioxidative Effects of N-acetylcysteine, Lipoic Acid, Taurine, and Curcumin in the Muscle of Cyprinus carpio L. Exposed to Cadmium

Antioxidative Effects of N-acetylcysteine, Lipoic Acid, Taurine, and Curcumin in the Muscle of Cyprinus carpio L. Exposed to Cadmium We investigated the muscle tissue of a teleost Cyprinus carpio L. to find out whether N-acetylcysteine (NAC), alpha-lipoic acid (LA), taurine (TAU), and curcumin (CUR) were able to counteract oxidative stress induced by acute exposure to cadmium (Cd). The muscle tissue was dissected 96 h after a single intraperitoneal injection of Cd (5 mg kg-1) and of antioxidant substances (50 mg kg-1). Using spectrophotometry, we determined the glutathione redox status, lipid peroxidation levels and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione disulphide reductase (GR). Accumulation of Cd in the muscle was analysed using inductively coupled plasma - optical emission spectrometry (ICP-OES). All substances lowered Cd levels in the following order of efficiency; LA=NAC>TAU=CUR. Cadmium increased SOD activity, but CAT activity declined, regardless of antioxidant treatment. Treatment with CUR induced GPx activity. Treatment with TAU lowered Cd due to higher total glutathione (tGSH). The most effective substances on lipid peroxidation were LA and NAC due to a greater Cd-lowering potential. It seems that the protective role of TAU, LA, and NAC is not necessarily associated with antioxidant enzymes, but rather with their own activity. Antioksidativni učinci N-acetilcisteina, lipoične kiseline, taurina i kurkumina u mišićnom tkivu šarana (Cyprinus carpio L.) tretiranih kadmijem Cilj istraživanja bio je utvrditi mogu li N-acetilcistein (NAC), α-lipoična kiselina (LA), taurin (TAU) i kurkumin (CUR) svojim antioksidativnim djelovanjem smanjiti razinu oksidativnog stresa u mišićnom tkivu šarana (Cyprinus carpio L.) akutno otrovanih kadmijem. Uzorci mišićnog tkiva skupljeni su 96 h nakon što su ribama intraperitonealno injicirani kadmij (5 mg kg-1) i ispitivani antioksidansi (50 mg kg-1). Primjenom spektrofotometrijskih metoda izmjereni su redoks status glutationa, razine lipidne peroksidacije te aktivnosti enzima superoksid dismutaze (SOD), katalaze (CAT), glutation peroksidaze (GPx) i glutation disulfid reduktaze (GR). Maseni udio kadmija u mišićnom tkivu izmjeren je s pomoću metode induktivno spregnute plazme - optičke emisijske spektrometrije (ICP-OES). Ispitivani spojevi smanjili su nakupljanje kadmija u tkivu šarana sljedećim redoslijedom: LA=NAC>TAU=CUR. Tretman šarana kadmijem izazvao je porast aktivnosti SOD, ali se aktivnost CAT smanjila bez obzira na primjenu antioksidativnih spojeva. Dodatak CUR pojačao je aktivnost GPx. Dodatak TAU povećao je razinu ukupnoga glutationa te smanjio nakupljanje kadmija. Svi spojevi osim CUR smanjili su razinu lipidne peroksidacije te pretpostavljamo da su LA i NAC pridonijeli detoksifikaciji kadmija. Rezultati istraživanja upućuju na to da testirani spojevi, osim CUR, imaju antioksidativni učinak.

Tissue-specific effects of fenthion on glutathione metabolism modulated by NAC and BSO in Oreochromis niloticus

Introduction: The present study was designed to understand the effects of organophosphate (OP) insecticide and avicide fenthion on cellular redox status and the role of reduced glutathione (GSH) on fenthion toxicity in the liver and kidney of Oreochromis niloticus as a model organism. N-acetylcysteine (NAC) and buthionine sulfoximine (BSO) were injected intraperitoneally to fenthion-exposed fish as modulators of GSH metabolism. GSH redox status, GSH-related enzyme activities, and thiobarbituric acid reactive substances (TBARS) contents were then measured spectrophotometrically at 24, 48, and 96 hours. To assess recovery from fenthion exposure, similar analyses were performed on fish transferred to non-treated water for 24, 48, and 96 hours. Results: Fenthion increased glutathione S-transferase (GST; EC 2.5.1.18) activity and caused changes in total GSH (tGSH), GSH and oxidized glutathione (GSSG) contents and glutathione peroxidase (GPx; EC 1.11.1.9) specific activity in the liver tissue over time. Increases observed in tGSH and GSSG contents at 24 hours were decreased by fenthion treatment at 96 hours. BSO caused a sharp decline in liver tGSH, GSH, and GSSG contents and an elevation in GST and γ-glutamyl transpeptidase (γ-GT; EC 2.3.2.2) enzyme activities. A significant decrease was observed in tGSH and GSH contents and, also, GST enzyme activities in the kidney at 48-hour fenthion treatment. On the contrary to the liver, a significant increase was observed in tGSH and GSH contents in the kidney by BSO injection. NAC application eliminated the decreasing effects of fenthion on GST activity in this tissue. NAC injection caused decreases in lipid peroxidation (LPO) levels. Decline in tGSH and GSH contents were maintained in the liver during the recovery period, and elevations in LPO levels in the kidney were observed during the same period. Conclusions: In conclusion, tissue-specific and time-dependent GSH redox status disturbance of fenthion were observed. BSO revealed the significance of GST-mediated GSH conjugation on the detoxification process of fenthion. NAC seemed useful to avoid the fenthion-related oxidative toxicity.

Modulation of Fenthion-Induced Oxidative Effects by BSO in the Liver of Cyprinus carpio L

The objective of the present study was to evaluate the oxidative stress potential of low-level organophosphate fenthion exposure with the modulatory effect of buthionine sulfoximine in the liver of Cyprinus carpio L. The fish were exposed to 20% of 96-hour LC50 of fenthion for 24 and 96 hours. Total and oxidized glutathione, thiobarbituric acid reactive substances, protein levels, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase, and catalase-specific enzyme activities were measured spectrophotometrically. There was a 15-day depuration period to evaluate the changes in the studied parameters. Fenthion caused a time-dependent depletion of the total and reduced glutathione levels. The oxidized/reduced glutathione ratio and catalase specific enzyme activity were reduced while the glutathione-S-transferase activity was elevated. Intraperitonal buthionine sulfoximine application disclosed the inhibitory effect of fenthion on superoxide dismutase and glutathione peroxidase activities, whereas glutathione-S-transferase activity was increased. There was no change in lipid peroxidation levels during the experiments. No amelioration was observed in the affected parameters except the glutathione-S-transferase activity in the 15-day depuration period. In conclusion, glutathione-S-transferase and catalase enzyme activities and total and reduced glutathione levels were better estimators to monitor the effects of fenthion in low concentration in the liver of C. carpio. The depuration period was not adequate to recover the antioxidant capacity.

In vivo Alterations in Glutathione-Related Processes, Lipid Peroxidation, and Cholinesterase Enzyme Activities in the Liver of Diazinon-Exposed Oreochromis niloticus

ABSTRACT Although its usage is partially banned in developed countries, organophosphate (OP) pesticide diazinon finds extensive agricultural application in our country (Turkey). This study was conducted to evaluate the effects of diazinon on total glutathione (tGSH), GSH-related enzymes, cholinesterase (ChE) enzyme activities, and lipid peroxidation in the liver of Oreochromis niloticus, a freshwater fish, as a model organism. Fish were exposed to 0.1, 1, and 2 mg/L sublethal concentrations of diazinon for 1, 7, 15, and 30 days. Total GSH levels, GSH-related enzyme and ChE-specific activities, and malondialdehyde (MDA) levels were analyzed using spectrophotometric methods. tGSH levels are decreased at 1 day, while they were increased in the long-term period. GSH-related enzyme activities are affected by diazinon exposure, except glutathione reductase (GR; EC 1.6.2.4). Diazinon displayed an oxidative stress-inducing potential and it increased lipid peroxidation. Similar inhibition levels were observed in acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BChE; EC 3.1.1.8.) enzyme activities, and these inhibitions were not dose dependent. ChE inhibition-related oxidative stress was observed using its correlation with elevated tGSH levels and increased glutathione S-transferase (GST; EC 2.5.1.18) enzyme activities; that reflects the diazinon-induced oxidative stress in the liver of O. niloticus. According to the results of the present study, tGSH level and GST-specific activity are suitable for reflecting the toxic effects of diazinon in fish.

Comparison of the protective effects of antioxidant compounds in the liver and kidney of Cd‐ and Cr‐exposed common carp

The aim of this study was to see whether the taurine (TAU), alpha‐lipoic acid (LA), curcumin (CUR), and N‐acetylcysteine (NAC) protection against oxidative stress caused by heavy metals is owed to the metal‐decreasing or antioxidative effect. In this context, liver and kidney tissues of common carp (Cyprinus carpio carpio L.) were exposed in vivo to model toxicants cadmium (Cd) and chromium (Cr). The tissues were dissected 96 h after intraperitoneal injection of the metals and antioxidant substances. Cd and Cr levels were determined in the liver using the ICP‐OES, but we could not obtain enough kidney tissue to make the same measurements in the kidney. The enzymatic activities of SOD, CAT, and GPx, and the GSH redox status and lipid peroxidation levels were analyzed using spectrophotometric methods. Of all investigated antioxidants, only NAC decreased metal levels in the liver. Cd had little effect on oxidative stress parameters, while Cr showed a weak prooxidative effect. Cotreatment with TAU/LA/CUR/NAC and Cr significantly increased liver SOD activity. Chromium induced kidney SOD and CAT, but all antioxidants lowered CAT activity. Cadmium reduced liver and increased kidney GSSG. NAC increased liver GSH, but the increase did not correlate with decrease in Cd. Curcumin given with Cd increased kidney and decreased liver lipid peroxidation, whereas TAU with Cr increased lipid peroxidation in both tissues. N‐Acetylcysteine was the most effective antioxidative agent, owing to its metal‐decreasing function as well as to its effects on the GSH redox status. We believe that the investigated antioxidant substances which may have been involved in the reduction of Cr caused an increase in SOD activity and a decrease in CAT activity. Changes in the GSSG levels in both tissues might be an adaptive response to the prooxidative potential of Cd. Because of their respective tissue‐ and metal‐dependent prooxidative effects, CUR and TAU deserve particular attention in regard to their use against metal toxicity, Cr in particular.

Sex-related effects of imidacloprid modulated by piperonyl butoxide and menadione in rats. Part II: genotoxic and cytotoxic potential

Abstract Despite its intended use, imidacloprid causes genotoxic and cytotoxic effects in mammals, especially in the presence of metabolic activation systems. The aim of this study was to determine to which extent these effects are sex related and how its metabolism modulators piperonyl butoxide and menadione affect its toxicity. Male and female Sprague-Dawley rats were injected with the intraperitoneal LD50 dose of imidacloprid alone (170 mg/kg) or pretreated with piperonyl butoxide (100 mg/kg) and menadione (25 mg/kg) for 12 and 24 h. Structural chromosome aberrations, abnormal cells and mitotic index were determined microscopically in bone marrow cells. Male rats showed susceptibility to the genotoxic effects of imidacloprid. Piperonyl butoxide was effective in countering this effect only at 24 h, whereas menadione exacerbated imidacloprid-induced genotoxicity. Piperonyl butoxide and menadione pretreatments increased the percentage of structural chromosome aberrations and abnormal cells in females. Imidacloprid decreased the mitotic index, whereas pretreatment with piperonyl butoxide and menadione showed improvement in both sexes. We believe that CYP450-mediated metabolism of imidacloprid is under the hormonal control and therefore that its genotoxicity is sex related. Piperonyl butoxide pretreatment also showed sex-related modulation. The hormonal effects on imidacloprid biotransformation require further investigation.

Prevalence of Beta-Thalassemia Trait and Abnormal Hemoglobins in the Province of Adıyaman, Turkey

Background/Aims: Thalassemia is one of the most common hereditary disorders in Turkey. The aim of this study was to determine the prevalence of the beta-thalassemia trait and abnormal hemoglobins in the province of Adıyaman in Turkey. Methods: The study included 3571 high school students of both sexes; aged 12–22 (mean 16.59 ± 1.34). After they received information about thalassemia, they were screened for beta-thalassemia and abnormal hemoglobin using complete blood count (CBC) and quantification of hemoglobin. Hemoglobin was fractionated using HPLC. Results: The beta-thalassemia trait was found in 38 students (1.06%), and abnormal hemoglobin in seven students (0.20%). Of the latter, four carried HbD Los Angeles, two HbS, and one HbE-Saskatoon. Conclusion: The prevalence of the beta-thalassemia trait and abnormal hemoglobin in the province of Adıyaman is low, compared to the rest of Turkey. Our results seem to reflect the heterogeneity of beta-thalassemia in the province of Adıyaman and may be of value for genetic counseling and premarital screening.

Tissue-Specific In Vivo Inhibition of Cholinesterases by the Organophosphate Fenthion in Oreochromis niloticus

This study was designed to elucidate the effect of the organophosphate fenthion exposure on cholinesterase‐specific activities in brain, liver, and kidney tissues of juvenile Oreochromis niloticus, and to define the best indicator tissue to fenthion exposure. The 96‐h LC50 value was determined as 2.27 mg/L and fish were exposed to 20% of this concentration for 24‐, 48‐, and 96‐h. Recovery periods in similar durations were provided to evaluate the ChE activities. AChE and BChE activities were determined spectrophotometrically. The activities of these enzymes were significantly inhibited in all the tissues tested, liver was the most and kidney was the least affected tissues. The inhibition percentages of AChE and BChE were at similar levels in the liver while BChE was more affected in kidney. BChE was not detected in the brain. A significant positive correlation in ChE inhibitions was found among tissues, and the effect of fenthion on ChE activities was tissue specific. In general enzymes activities were not significantly recovered in 96‐h recovery period; however, an elevation in AChE inhibition was observed in brain. Based on the data of this study, the liver may be suggested as the best indicator tissue especially for phosphorothioate exposure.

Sex-, tissue-, and exposure duration-dependent effects of imidacloprid modulated by piperonyl butoxide and menadione in rats. Part I: oxidative and neurotoxic potentials

Abstract Earlier research has evidenced the oxidative and neurotoxic potential of imidacloprid, a neonicotinoid insecticide, in different animal species. The primary aim of this study was to determine how metabolic modulators piperonyl butoxide and menadione affect imidacloprid’s adverse action in the liver and kidney of Sprague-Dawley rats of both sexes. The animals were exposed to imidacloprid alone (170 mg kg-1) or in combination with piperonyl butoxide (100 mg kg-1) or menadione (25 mg kg-1) for 12 and 24 h. Their liver and kidney homogenates were analysed spectrophotometrically for glutathione peroxidase, glutathione S-transferase, catalase, total cholinesterase specific activities, total glutathione, total protein content, and lipid peroxidation levels. Imidacloprid displayed its prooxidative and neurotoxic effects predominantly in the kidney of male rats after 24 h of exposure. Our findings suggest that the observed differences in prooxidative and neurotoxic potential of imidacloprid could be related to differences in its metabolism between the sexes. Co-exposure (90-min pre-treatment) with piperonyl butoxide or menadione revealed tissue-specific effect of imidacloprid on total cholinesterase activity. Increased cholinesterase activity in the kidney could be an adaptive response to imidacloprid-induced oxidative stress. In the male rat liver, co-exposure with piperonyl butoxide or menadione exacerbated imidacloprid toxicity. In female rats, imidacloprid+menadione co-exposure caused prooxidative effects, while no such effects were observed with imidacloprid alone or menadione alone. In conclusion, sex-, tissue-, and duration-specific effects of imidacloprid are remarkable points in its toxicity Sažetak Rezultati ranijih istraživanja pokazali su oksidativni i neurotoksični potencijal imidakloprida, neonikotinoidnog insekticida, u različitih životinjskih vrsta. Primarni je cilj ovog istraživanja bio utvrditi kako modulatori metabolizma piperonil butoksid i menadion utječu na nepovoljne učinke imidakloprida na jetra i bubrege muških i ženskih štakora soja Sprague-Dawley. Životinje su 12 h odnosno 24 h bile izložene samo imidaklopridu (170 mg kg-1) ili njegovoj kombinaciji s piperonil butoksidom (100 mg kg-1) odnosno menadionom (25 mg kg-1). U homogenatima jetara i bubrega spektrofotometrijski su utvrđene razine glutation peroksidaze, glutation S-transferaze, katalaze, specifične aktivnosti ukupne kolinesteraze, ukupni glutation, ukupni proteini te razine lipidne peroksidacije. Imidakloprid se pokazao prooksidativnim i neurotoksičnim uglavnom u bubrezima muških štakora nakon 24-satne izloženosti. Naši rezultati upućuju na to da su razlike u prooksidativnom i neurotoksičnom djelovanju imidakloprida povezane sa spolnim razlikama. Predtretmanom piperonil butoksidom odnosno menadionom (90 min prije davanja imidakloprida) otkriveno je da imidakloprid djeluje na ukupnu aktivnost kolinesteraze specifično za pojedina tkiva. Povišena aktivnost kolinesteraza u bubrezima mogla bi odražavati prilagodbu na oksidativni stres uzrokovan imidaklopridom. Piperonil butoksid odnosno menadion u jetrima muških štakora samo su pogoršali toksičnost imidakloprida. U ženki je djelovanje imidakloprida s menadionom bilo prooksidativno; takvo se djelovanje nije vidjelo nakon primjene samo imidakloprida odnosno samo menadiona. Vjerujemo da je promjenjivo djelovanje imidakloprida s obzirom na spol, tkivo i trajanje izloženosti važno za daljnja istraživanja njegove toksičnosti