Study of quinalphos (an environmental oestrogenic insecticide) formulation (Ekalux 25 E.C.)-induced damage of the testicular tissues and antioxidant defence systems in Sprague-Dawley albino rats

Effects of fluoride toxicity on the male reproductive system: A review

BACKGROUND

Fluoride toxicity and fluorosis is an emerging global problem. Fluoride has long been added to water for dental caries prevention; however, it has a variety of damaging consequences on human bodies. The aim of this paper is to analyse all the literature available on the effects of fluoride toxicity on male reproductive system.

METHODS

Research papers were collected using various methods of data collection like Pubmed, Scopus, and Google Scholar from 1980 to 2024, and then reviewed thoroughly.

RESULTS

Fluoride is known to cause various histopathological and biochemical alterations in the male reproductive system. It also affects fertility, semen quality, sperm number and quality,the process of spermatogenesis and spermiogenesis. Key changes caused by fluoride in male reproductive system include structural defects in the flagellum, acrosome, and nucleus of spermatids and epididymal spermatozoa. Degenerative changes in Leydig cells result in reduced testosterone production, causing regression of seminiferous tubules and structural damage to the epididymis, ultimately terminating spermatogenesis which leads to infertility. Decrease in levels of testosterone and activities of various antioxidant enzymes resulting in greater oxidative stress was also seen.

CONCLUSIONS

Fluoride has various detrimental effects on male reproductive system and overall reproductive health. This type of study is important for understanding the effects of fluoride toxicity so that health officials can guide public about safe fluoride exposure limits and the damages it can cause in higher concentrations. Studies using various natural and synthetic ameliorative substances mentioned in the text later can prove to be helpful for development of various therapeutic approaches to mitigate the effects of fluoride toxicity.

GC-MS-based profiling and ameliorative potential of Carissa opaca Stapf ex Haines fruit against cardiac and testicular toxicity: An In vivo study

Fruit of Carissa opaca Stapf ex Haines (C. opaca) is a feed additive and is commonly used against cardiac dysfunction, fever, asthma, diarrhea, gastrointestinal ailments, and skin diseases. In this study, we aimed to evaluate the metabolic profile and antioxidant potential of C. opaca fruit against carbon tetrachloride (CCl4)-induced cardiotoxicity and testicular toxicity in rats. Gas Chromatoghraphy-Mass Spectrometry (GC-MS) analysis of C. opaca fruit for the identification of potential metabolic profile, followed by methanolic extract of C. opaca and its derived fractions including n-hexane, ethyl acetate, chloroform, butanol, and aqueous were used to assess the antioxidant potential of fruits. Ten groups of rats received different treatments and got evaluated for cardiac and testicular antioxidant enzymes, histological architecture, and serum hormonal levels. GC-MS analysis of methanolic extract of C. opaca fruit showed the presence of some bioactive metabolites like cyclodecane, diethyl 2,6-pyridine dicarboxylate, tetrahydro-geraniol, S-[2-[N, N-Dimethylamino]ethyl]morpoline, 2,3-Methylenedioxyphenol, alpha-d-Glucopyranoside, 5,10-Diethoxy-2,3,7,8-tetrahydro-1H, 6H-dipyrrolo [1,2-a; 1',2'-d] pyrazine and 1,3-Benzothiazol-2(3H)-one,3-(3,3-dimethyl-1-oxobutyl) that corresponds the medicinal properties of C. opaca fruit. Prepared fractions of C. opaca fruits mitigated the toxicity induced by CCl4 in the heart and testicular tissues of rats. Oxidative stress was caused by the inhibition of activities of glutathione and other antioxidant enzymes of the body, while on the other hand elevating the levels of nitrite and hydrogen peroxide. Treatment with C. opaca fruit extract normalized the levels of enzymes, reproductive hormones, and free radicals thus restoring the histopathological and enzymatic biomarkers towards the normal group. The study supports the indigenous use of fruits as an alternative medicine against cardiac dysfunction by providing scientific evidence of protection against CCl4-induced injuries, and it also concludes the antioxidant defensive role in testicular tissues.

Organophosphorus pesticide quinalphos (Ekalux 25 E.C.) reduces sperm functional competence and decreases the fertilisation potential in Swiss albino mice

Quinalphos (QP) is one of the most commonly used organophosphate pesticide for agriculture. In this study, adult Swiss albino male mice were orally administered with 0.25, 0.5 and 1.0 mg/kg of QP (Ekalux 25 E.C.) for ten consecutive days and the reproductive function was assessed at 35 and 70 days after QP treatment. At highest dose (1.0 mg/kg), QP exposure resulted in significant decrease in motility and increase in sperm head defects and DNA damage. Pharmacokinetic data showed a threefold increase in concentration of QP in the testis as compared to serum. QP was detectable in testes even after 24 hr of administration indicating slow clearance from tissue. In addition, high oestradiol, low testosterone level with a parallel increase in aromatase and cytochrome P450 transcript levels was observed. Significant decrease in fertilisation, lower blastocyst rate and poor blastocyst quality was observed when spermatozoa collected from QP exposed mice were subjected to in vitro fertilisation. In conclusion, exposure of QP to male mice decreases the sperm functional competence and fertilising ability, which appears to be mediated through elevated oxidative stress and altered steroidogenesis in testes.

Testicular protective and antioxidant effects of selenium nanoparticles on Monosodium glutamate-induced testicular structure alterations in male mice

Background

Selenium has a protective antioxidant effect on several tissues. Monosodium glutamate (MSG), MSG has been known as flavor enhancer that influences reversely on male reproductive systems and having a number of side effects, including reproductive toxicity.

Objectives

The current study aims to evaluate the possible ameliorative functions of selenium nanoparticles (SeNPs) on MSG-induced reproductive toxicity.

Materials and methods

In total, 42 male mice included in this study were divided into six groups: control, MSG (LD), MSG (HD), SeNPs, MSG (LD) plus SeNPs and finally MSG (HD) plus SeNPs. Testosterone hormone, tumor necrosis factor-alpha (TNF-α), as well as the antioxidant biomarkers: superoxide dismutase [SOD], glutathione peroxidase [GPx], catalase [CAT] and marker of lipid peroxidation [MDA], were examined. Histological and comet assay variations in the testicular tissues as markers of testicular damage after the MSG administration in two doses (MSG-LD and MSG-HD) either alone or combined with SeNPs.MSG in two doses (LD and HD) genotoxic effects were also evaluated and the ameliorative role of SeNPs on the testicular tissues were recorded.

Results

Results proved that the administration of SeNPs diminished the effect of MSG (LD and HD)-that induced decrease in testosterone hormone levels and elevated oxidative stress markers markedly. SeNPs had a potent antioxidant effect and elevated the antioxidant enzymes significantly and decreased lipid peroxidation markers as compared with MSG either (LD and HD) groups.

Conclusion

It is clear from the data that SeNPs inhibit testicular injury and improve the antioxidant state in male mice.

Investigating the protective effect of aerobic exercise on oxidative stress and histological damages of testicular tissue associated with chlorpyrifos in male rats

The current study aimed to investigate the protective effects of moderate aerobic exercise against chlorpyrifos (CPF)-induced testes dysfunction. In excremental study, 48 adult male albino rats were randomly allocated into 16 groups of 3 rats each. Twelve experimental groups received intraperitoneal injection (5 days a week) of either 1.0 or 3.0 mg/kg body weight CPF in DMSO for 2, 4 or 6 consecutive weeks. Seven of these experimental groups were subjected to run at moderate exercise intensity for 5 days per week over 2 weeks, whereas the other groups were not. Two groups (sham groups) were administered to the equal volume of vehicle (DMSO) for 4 or 6 consecutive weeks. The remaining two groups comprised the control groups including a sedentary and an exercise-trained control group. Exercise training leads to a markedly increase in testicular superoxide dismutase (SOD) activity in CPF-exposed rats compared with corresponding sedentary animals (p < .05). Lipid peroxidation level was found to be significantly decreased in the testis of exercised animals that had been exposed to CPF (p < .05). Our results suggest that aerobic exercise can alleviate the oxidative stress induced by sub-acute CPF exposure in testis. Exercise training could barely mitigate CPF-induced testicular damages in rats.

Zinc Ameliorate Oxidative Stress and Hormonal Disturbance Induced by Methomyl, Abamectin, and Their Mixture in Male Rats

Exposure to mixtures of toxicants (e.g., pesticides) is common in real life and a subject of current concern. The present investigation was undertaken to assess some toxicological effects in male rats following exposure to methomyl (MET), abamectin (ABM), and their combination (MET+ABM), and to evaluate the ameliorative effect of zinc co-administration. Three groups of rats were designated for MET, ABM, and the mixture treatments. Three other groups were designated for zinc in conjunction with the pesticides. Additionally, one group received water only (control), and the other represented a positive zinc treatment. The obtained results revealed that MET was acutely more toxic than ABM. The tested pesticides induced significant elevation in lipid peroxidation and catalase levels, while declined the levels of the other tested parameters e.g., Superoxide dismutase (SOD), Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Glutathione reductase (GR), Cytochrome P₄₅₀ (CYP₄₅₀), testosterone, and thyroxine). Biochemical alterations induced by the mixture were greater than those recorded for each of the individual insecticides. The joint action analysis, based on the obtained biochemical data, revealed the dominance of antagonistic action among MET and ABM. Zinc supplementation achieved noticeable ameliorative effects. It was concluded that zinc may act as a powerful antioxidant, especially in individuals who are occupationally exposed daily to low doses of such pesticides.

Steroidogenesis in Leydig cells: effects of aging and environmental factors

Serum testosterone (TS) levels decrease with aging in both humans and rodents. Using the rat as a model system, it was found that age-related reductions in serum TS were not due to loss of Leydig cells, but rather to the reduced ability of the Leydig cells to produce TS in response to luteinizing hormone (LH). Detailed analyses of the steroidogenic pathway have suggested that two defects along the pathway, LH-stimulated cAMP production and cholesterol transport to and into the mitochondria, are of particular importance in age-related reductions in TS production. Although the mechanisms involved in these defects are far from certain, increasing oxidative stress appears to play a particularly important role. Interestingly, increased oxidative stress also appears to be involved in the suppressive effects of endocrine disruptors on Leydig cell TS production.

Responses of the Antioxidant and Osmoregulation Systems of Fish Erythrocyte Following Copper Exposures in Differing Calcium Levels

Freshwater fish Oreochromis niloticus were exposed to Cu in differing Ca²⁺ levels (15, 30 and 90 mg/L), using acute (0.3 µM, 3 d) and chronic (0.03 µM, 30 d) exposure protocols and enzyme activities related to the antioxidant (catalase, CAT, EC 1.11.1.6; superoxide dismutase, SOD, EC 1.15.1.1; glutathione peroxidase, GPx, EC 1.11.1.9) and osmoregulation (Total, Na⁺/K⁺-ATPase, EC 3.6.3.9, Mg²⁺-ATPase, EC 3.6.3.2) systems in the erythrocytes were measured. Activities of antioxidant enzymes generally decreased significantly following either Ca²⁺ alone or Ca²⁺+Cu combinations in both acute and chronic exposures. Na⁺/K⁺-ATPase activity significantly decreased in chronic exposures, though there was no clear trend in acute exposures. Mg²⁺-ATPase activity increased significantly in acute exposures, but not in chronic ones. There were more significant alterations in acute exposure compared to chronic ones. There was no clear trend regarding Cu toxicity and its relationship with Ca²⁺, which may possibly be prompted by the compensatory mechanisms of the enzymes. It may be concluded that freshwater fish erythrocytes may face different degrees of more physiological stress from different waters.

Evaluation of oxidative stress and genotoxicity in organophosphorus insecticide formulators

The aim of this study was to evaluate genotoxicity and oxidative stress in workers who formulate organophosphorus (OP) pesticides. In this survey, blood leukocytes and erythrocytes of a group of 21 pesticide formulating workers and an equal number of control subjects were examined for genotoxicity and oxidative stress parameters. The mean comet tail length and mean comet length were used to measure DNA damage. Lipid peroxidation level, catalase, superoxide dismutase (SOD) and glutathione peroxidase activities in erythrocytes were analysed as biomarkers of oxidative stress. In addition, the acetylcholinesterase activity was measured as a biomarker of toxicity. The average duration of employment of workers in the factory was 97 months. Results indicated that chronic exposure (multiple5dose, greater than or equal to 6 months duration) to OP pesticides was associated with increased activities of catalase, SOD and glutathione peroxidase in erythrocytes. The level of lipid peroxidation and acetylcholinesterase activity did not show any significant differences between the two groups. The results also indicated that chronic exposure to OP pesticides was associated with increased DNA damage. It is concluded that human chronic exposure to OP pesticides may result in stimulated antioxidant enzymes and increased DNA damage in the absence of depressed acetylcholinesterase levels. Routine genotoxicity monitoring concomitant to acetylcholinesterase activity in workers occupationally exposed to OP insecticides is suggested.

Evaluation of lemon fruit extract as an antioxidant agent against histopathological changes induced by cyclophosphamide in the testes of albino mice

Introduction

The aim of this study was to determine the protective effects of lemon fruit extracts (LFE) against histopathological changes induced in the testes of male mice treated with cyclophosphamide (CP).

Methods

Thirty male mice were divided evenly into six groups: 1) group 1: the controls, 2) group 2: treated with LFE (10 ml/kg b wt.), 3) group 3: treated with CP (10 mg/kg b wt.), 4) group 4: treated with CP (20 mg/kg b wt.), 5) group 5: treated with LFE (10 ml/kg) + CP (10 mg/kg), 6) group 6: treated with LFE (10 ml/kg) + CP (20 mg/kg).

Results

Histological examination of the testes of mice treated with CP revealed histopathological changes, such as atrophy, degeneration, incomplete spermatogenic series in most seminiferous tubules, and spermatogenic necrosis with pyknotic nuclei. Advanced degree of improvement was seen in testes of mice treated with LFE co-administered with CP. Most of the seminiferous tubules restored their normal structure and spermatogenic layers appeared semi-normal with complete spermatogenic series.

Conclusion

Lemon fruit extract in conjunction with drug treatment protects the testicular tissue against CP-induced testicular injury in mice.

Fruit and vegetable intake and their pesticide residues in relation to semen quality among men from a fertility clinic

STUDY QUESTION

Is consumption of fruits and vegetables with high levels of pesticide residues associated with lower semen quality?

SUMMARY ANSWER

Consumption of fruits and vegetables with high levels of pesticide residues was associated with a lower total sperm count and a lower percentage of morphologically normal sperm among men presenting to a fertility clinic.

WHAT IS KNOWN ALREADY

Occupational and environmental exposure to pesticides is associated with lower semen quality. Whether the same is true for exposure through diet is unknown.

STUDY DESIGN, SIZE, DURATION

Men enrolled in the Environment and Reproductive Health (EARTH) Study, an ongoing prospective cohort at an academic medical fertility center. Male partners (n = 155) in subfertile couples provided 338 semen samples during 2007-2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Semen samples were collected over an 18-month period following diet assessment. Sperm concentration and motility were evaluated by computer-aided semen analysis (CASA). Fruits and vegetables were categorized as containing high or low-to-moderate pesticide residues based on data from the annual United States Department of Agriculture Pesticide Data Program. Linear mixed models were used to analyze the association of fruit and vegetable intake with sperm parameters accounting for within-person correlations across repeat samples while adjusting for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Total fruit and vegetable intake was unrelated to semen quality parameters. High pesticide residue fruit and vegetable intake, however, was associated with poorer semen quality. On average, men in highest quartile of high pesticide residue fruit and vegetable intake (≥1.5 servings/day) had 49% (95% confidence interval (CI): 31%, 63%) lower total sperm count and 32% (95% CI: 7%, 58%) lower percentage of morphologically normal sperm than men in the lowest quartile of intake (<0.5 servings/day) (P, trend = 0.003 and 0.02, respectively). Low-to-moderate pesticide residue fruit and vegetable intake was associated with a higher percentage of morphologically normal sperm (P, trend = 0.04).

LIMITATIONS, REASONS FOR CAUTION

Surveillance data, rather than individual pesticide assessment, was used to assess the pesticide residue status of fruits and vegetables. CASA is a useful method for clinical evaluation but may be considered less favorable for accurate semen analysis in the research setting. Owing to the observational nature of the study, confirmation is required by interventional studies as well.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first report on the consumption of fruits and vegetables with high levels of pesticide residue in relation to semen quality. Further confirmation of these findings is warranted.

STUDY FUNDING/COMPETING INTERESTS

Supported by National Institutes of Health grants ES009718, ES022955, ES000002, P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16. None of the authors has any conflicts of interest to declare.

Effects of curcumin and tannic acid on the aluminum- and lead-induced oxidative neurotoxicity and alterations in NMDA receptors

Exposure to aluminum (Al) and lead (Pb) can cause brain damage. Also, Pb and Al exposure alters N-methyl-d-aspartate receptor (NMDAR) subunit expression. Polyphenols such as tannic acid and curcumin are very efficient chelator for metals. The effects of curcumin and tannic acid (polyphenols) on Al(3+)- and Pb(2+)-induced oxidative stress were examined by investigating lipid peroxidation (LPO) levels, antioxidant enzyme activities, acetyl cholinesterase (AChE) activity and also NMDA receptor subunits 2A and 2B concentrations in the brain tissue of rats sub-chronically. Rats were divided into seven groups as control, Al, Pb, aluminum-tannic acid treatment (AlT), aluminum-curcumin treatment (AlC), lead-tannic acid treatment (PbT) and lead-curcumin treatment (PbC). After 16 weeks of treatment, LPO levels in the brain and hippocampus were higher in Al(3+)-exposed rats than that of Pb(2+)-exposed group. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in brain tissue of Al- and Pb-exposed rats increased significantly compared with control, while catalase (CAT) and AChE activities decreased. It was observed that metal exposure affected NR2A concentrations more than NR2B concentrations and also that polyphenol treatments increased these receptor protein concentrations.

The enzyme toxicity and genotoxicity of chlorpyrifos and its toxic metabolite TCP to zebrafish Danio rerio

Chlorpyrifos is a broad-spectrum organophosphorus insecticide (O,O-diethyl -O-3,5,6-trichloro-2-pyridyl phosphorothioate) that is used in numerous agricultural and urban pest controls. The primary metabolite of chlorpyrifos is 3,5,6-trichloro pyridine-2-phenol (TCP). Because of its strong water solubility and mobility, this harmful metabolite exists in the environment in a large amount. Although TCP has potentially harmful effects on organisms in the environment, few studies have addressed TCP pollution. Therefore, this study was undertaken to investigate the effect of chlorpyrifos and TCP on the microsomal cytochrome P450 content in the liver, on the activity of NADPH-P450 reductase and antioxidative enzymes [catalase (CAT) and superoxide dismutase (SOD)], and on reactive oxygen species (ROS) generation and DNA damage in zebrafish. Male and female zebrafish were separated and exposed to a control solution and three concentrations of chlorpyrifos (0.01, 0.1, 1 mg L(-1)) and TCP (0.01, 0.1, 0.5 mg L(-1)), respectively, sampled after 5, 10, 15, 20 and 25 days. The results indicated that the P450 content and the NADPH-P450 reductase and antioxidative enzyme (CAT and SOD) activities could be induced by chlorpyrifos and TCP. DNA damage of zebrafish was enhanced with increasing chlorpyrifos and TCP concentrations. Meanwhile, chlorpyrifos and TCP induced a significant increase of ROS generation in the zebrafish hepatopancreas. In conclusion, this study proved that chlorpyrifos (0.01-1 mg L(-1)) and TCP (0.01-0.5 mg L(-1)) are both highly toxic to zebrafish.

Quercetin ameliorates atrazine-induced changes in the testicular function of rats

The protective effect of quercetin (QT) on atrazine (ATZ)-induced testicular damage in rats was investigated. Sexually mature male Wistar rats (weighing 220-250 g) divided into four groups with six animals in each group were given ATZ (120 mg kg(-1); 1/16 of the median lethal dose for an oral dose) and/or QT (10 mg kg(-1)) daily via gavage for 16 days. By the end of day 16, rats given ATZ alone had significantly lower sperm counts, daily spermatozoa production, and sperm motility and significantly higher abnormal sperm numbers than the untreated control rats. The rats given ATZ alone also had significantly decreased 3β-hydroxtsteroid dehydrogenase (HSD) and 17β-HSD activities than the control rats. Lactate dehydrogenase activity and malondialdehyde levels were significantly increased, whereas superoxide dismutase activity decreased but glutathione levels remain unaffected after ATZ exposure. These changes were reversed toward control values in the QT + ATZ-treated animals, though the sperm motility was 28% below the control levels but was still higher than in the ATZ-treated rats. The results indicate that QT might improve testicular function of rats exposed to ATZ, but its protective effect on sperm motility might be partial.

Potential pharmacological strategies for the improved treatment of organophosphate-induced neurotoxicity

Organophosphates (OP) are highly toxic compounds that cause cholinergic neuronal excitotoxicity and dysfunction by irreversible inhibition of acetylcholinesterase, resulting in delayed brain damage. This delayed secondary neuronal destruction, which arises primarily in the cholinergic areas of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, could be largely responsible for persistent profound neuropsychiatric and neurological impairments such as memory, cognitive, mental, emotional, motor, and sensory deficits in the victims of OP poisoning. The therapeutic strategies for reducing neuronal brain damage must adopt a multifunctional approach to the various steps of brain deterioration: (i) standard treatment with atropine and related anticholinergic compounds; (ii) anti-excitotoxic therapies to prevent cerebral edema, blockage of calcium influx, inhibition of apoptosis, and allow for the control of seizure; (iii) neuroprotection by aid of antioxidants and N-methyl-d-aspartate (NMDA) antagonists (multifunctional drug therapy), to inhibit/limit the secondary neuronal damage; and (iv) therapies targeting chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may prevent secondary neuronal damage in both early and late stages of OP poisoning, and thus may be a beneficial approach to treating the neuropsychological and neuronal impairments resulting from OP toxicity.

Chlorpyrifos induced testicular damage in rats: ameliorative effect of glutathione antioxidant

This study investigated the induction of oxidative stress in the testes of adult rats exposed to chlorpyrifos (CPF). CPF was administered orally, in a dose of 30 mg/kg body weight to male rats for 90 days, twice weekly. Coadministration of water-soluble nonenzymatic antioxidant glutathione (GSH) was performed in a dose of 100 mg/kg body weight, orally, for the same period. Another two groups of male rats were administered GSH and corn oil, respectively. The activities of superoxide dismutase and GSH reductase were decreased while the levels of lipid peroxidation were increased in the testicular tissues of the exposed animals. Testosterone level in the serum was significantly decreased. A decrease in the histochemical determination of testicular alkaline phosphatase was observed in CPF-treated rats. A significant decrease in all stages of spermatogenesis in the seminiferous tubules was recorded in the exposed animals. Coadministration of GSH restored these parameters.

Antioxidant mediated ameliorative steroidogenesis by Commelina benghalensis L. and Cissus quadrangularis L. against quinalphos induced male reproductive toxicity

Quinalphos (QP) is speculated to cause endocrine disruption through the generation of reactive oxygen species (ROS) by oxidative stress (OS). Exposure of QP decreased testosterone level considerably which resulted in reduced viable sperms in mice. The QP induced toxicity is initiated by the formation of free radicals as it is evidenced from the increased Lipid peroxidation (LPO) and diminution of antioxidant enzymes in testicular tissue. Increased serum cholesterol and reduced testicular cholesterol indicated the inhibition of cholesterol transport and biosynthesis in testicular tissues. Lack of cholesterol in testicular tissue impaired the steroidogenesis by down-regulating the expression of StAR protein, Cytochrome P450, 3β-HSD and 17β-HSD leading to reduced testosterone level. Treatment of Commelina benganlensis (CBE) and Cissus quadrangularis (CQE) significantly recovered the alterations in antioxidant profiles as well as increased LPO, thereby recovering the decreased mRNA expression levels of intermediate enzymes. However, CQE effectively protected the OS and prevented the inhibition of steroidogenesis thereby preventing male infertility.

Photocatalytic actions of the pesticide metabolite 2-hydroxyquinoxaline: destruction of antioxidant vitamins and biogenic amines – implications of organic redox cycling

Toxicity of the pesticide quinalphos may comprise secondary, delayed effects by its main metabolite 2-hydroxyquinoxaline (HQO). We demonstrate that HQO can destroy photocatalytically vitamins C and E, catecholamines, serotonin, melatonin, the melatonin metabolite AMK (N(1)-acetyl-5-methoxykynuramine), and unsubstituted and substituted anthranilic acids when exposed to visible light. In order to avoid HQO-independent ascorbate oxidation by light and to exclude actions by hydroxyl radicals, experiments on this vitamin were carried out in ethanolic solutions. Other substances tested (vitamin E, melatonin, anthranilic acids) were also photocatalytically destroyed by HQO in ethanol. After product analyses had indicated that HQO was not, or only poorly, degraded in the light, despite its catalytic action on other compounds, we followed directly the time course of HQO and ascorbate concentrations in ethanol. While ascorbate was largely destroyed, no change in HQO was demonstrable within 2 h of incubation. Destruction was not prevented by the singlet oxygen quencher DABCO. Obviously, HQO is capable of undergoing a process of organic redox cycling, perhaps via an intermediate quinoxaline-2-oxyl radical. Health problems from HQO intoxication may not only arise from the loss of valuable biomolecules, such as antioxidant vitamins and biogenic amines, but also from the formation of potentially toxic products. Dimerization and oligomerization are involved in several oxidation processes catalyzed by HQO, especially in the indoleamines, in dopamine, and presumably also in vitamin E. Melatonin oxidation by HQO did not only lead to the well-known - and usually protective - metabolite AFMK (N(1)-acetyl-N(2)-formyl-5-methoxykynuramine), but also to a high number of additional products, among them dimers and trimers. DABCO did not prevent melatonin destruction, but changed the spectrum of products. Serotonin was preferentially converted to a dimer, which can further oligomerize. Several indole dimers are known to be highly neurotoxic, as well as oxidation products formed from catecholamines via the adrenochrome/noradrenochrome pathway. Destruction of melatonin may cause deficiencies in circadian physiology, in immune functions and in antioxidative protection.

Effect of Carissa opaca leaves extract on lipid peroxidation, antioxidant activity and reproductive hormones in male rats

BACKGROUND

Carissa opaca leaves are traditionally used in the treatment of male dysfunction and hormonal disorder as well as in oxidative stress in Pakistan and Asia. The present study was designed to assess the protective effects of methanolic extract of Carissa opaca leaves (MLC) on carbon tetrachloride (CCl4)-induced reproductive stress in male rats and bioactive constituents responsible for the activity.

METHODS

CCl4 was induced in 42 male rats for eight weeks and checked the protective efficacy of methanolic extract of Carissa opaca leaves at various hormonal imbalances, alteration of antioxidant enzymes, DNA fragmentation levels and lipid peroxidation caused testicular fibrosis in testis while High performance Liquid Chromatography (HPLC) was used for detection of bioactive components.

RESULTS

HPLC characterization revealed the presence of isoquercitin, hyperoside, vitexin, myricetin and kaempherol. CCl4 caused significant alteration in the secretion of reproductive hormones. Activity of antioxidant enzymes viz; catalase, superoxide dimutase and phase II metabolizing enzymes including glutathione peroxidase, glutathione reductase and reduced glutathione was decreased while DNA fragmentation, hydrogen per oxide contents and thiobarbituric acid reactive substances (TBARS) were increased with CCl4 treatment. Co-administration of 100 mg/kg and 200 mg/kg b.w. MLC effectively ameliorated the alterations in the biochemical markers; hormonal and molecular levels.

CONCLUSION

Protective effects of methanolic extract of Carissa opaca against CCl4-induced antioxidant and hormonal dysfunction which might be due to bioactive compound present in extract.

Ameliorating effect of various fractions of Rumex hastatus roots against hepato- and testicular toxicity caused by CCl4

Effect of methanolic extract of Rumex hastatus roots (MRR) and its derived fractions, n-hexane (HRR), ethyl acetate (ERR), chloroform (CRR), butanol (BRR), and aqueous extract (ARR), was studied against carbon tetrachloride (CCl4) induced hepato and testicular toxicity in rats. Intraperitoneal dose of 20 percent CCl4 (0.5 ml/kg bw) was administered twice a week for eight weeks to a group of rats. Other groups were given CCl4 and various fractions of R. hastatus roots (200 mg/kg bw). CCl4 treatment depleted glutathione contents and activities of antioxidant enzymes while increased the concentration of lipid peroxides (TBARS) along with corresponding DNA injuries and histopathological damages. Supplementation with various fractions of R. hastatus roots (200 mg/kg body weight) attenuated the toxicity of CCl4 in liver and testis tissues through improvement in the serological, enzymatic, and histological parameters towards the normal. Posttreatment of R. hastatus roots (200 mg/kg body weight) also reversed the alteration in reproductive hormonal secretions and DNA damages in CCl4 treated rats. The results clearly demonstrated that R. hastatus treatment augments the antioxidants defense mechanism and provides the evidence that it may have a therapeutic role in free radical mediated diseases.

Effect of tea (Camellia sinensis) and olive (Olea europaea L.) leaves extracts on male mice exposed to diazinon

The present study was aimed to evaluate the effects of tea and olive leaves extracts and their combination in male mice intoxicated with a sublethal concentration of diazinon. Exposure of mice to 6.5 mg/kg body weight of diazinon for seven weeks resulted in statistical increases of serum alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, alkaline phosphatase, creatine kinase, creatinine, glucose, triglycerides, and cholesterol, while the value of serum total protein was declined. Treating diazinon-intoxicated mice with tea and olive leaves extracts or their combination significantly attenuated the severe alterations in these hematobiochemical parameters. Moreover, the results indicated that the supplementation with combination of tea and olive leaves extracts led to more attenuation effect against diazinon toxicity. Additionally, these new findings suggest that the effect of tea and olive leaves extracts and their combination against toxicity of diazinon may be due to antioxidant properties of their chemical constituents. Finally, the present study indicated that the extracts of tea and olive leaves and their combination can be considered as promising therapeutic agents against hepatotoxicity, cardiotoxicity, nephrotoxicity, and metabolic disorders induced by diazinon and maybe by other toxicants and pathogenic factors.

Genotoxicity associated with oxidative damage in the liver and kidney of mice exposed to dimethoate subchronic intoxication

BACKGROUND AND AIMS

Because of the widespread use of pesticides for domestic and industrial applications, the evaluation of their toxic effects is of major concern to public health. The aim of the present study was to investigate the propensity of dimethoate (DM), an organophosphorus pesticide, to cause oxidative damage in the liver and kidney of mice and its associated genotoxic effect.

METHODS

DM was administered intraperitoneally at doses of 1, 5, 10, 15, and 30 mg/kg body weight for 30 consecutive days in BALB/c mice. Oxidative stress was monitored in the kidney and liver by measuring malondialdehyde level, protein carbonyl concentration, and the catalase activity. The genotoxicity of DM was assessed by the comet assay in vivo.

RESULTS AND DISCUSSION

Our results indicated that DM inhibited acetylcholinesterase activities in the liver and kidney of treated mice. DM increased lipid peroxidation and protein carbonyl levels in the liver and kidney in a dose-dependent manner. Catalase activity was found to be significantly increased in the liver and kidney at doses higher than 5 mg/kg body weight.

CONCLUSIONS

Our study demonstrated that DM induced DNA damage in the liver and kidney of treated mice in a dose-dependent manner; this induction was associated to DM-induced oxidative stress. Further investigations are needed to prove the implication of oxidative stress in genotoxicity induced by DM.

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.

Effect of Celastrus paniculatus seed oil (Jyothismati oil) on acute and chronic immobilization stress induced in swiss albino mice

Stress alters the homeostasis and is produced by several factors. Immobilization stress induced due to reduced floor area provided for the mobility results in the imbalance of oxidant and antioxidant status. The modern computer savvy world decreases human mobility in the working environment, leading to the formation of oxygen free radicals and if left untreated might result in severe health problems like hypertension, cardiovascular disease, premature aging and brain dysfunction. Hence, modern medicines rely upon the medicinal plants for some drugs with zero side effects. In this context, Jyothismati oil (JO), extracted from Celastrus paniculatus seeds, was used to treat acute and chronic immobilization induced experimentally. C. paniculatus plant is considered to be rich in antioxidant content and so the seed oil extract's efficacy was tested against immobilization stress in albino mice. The animals were kept in a restrainer for short and long durations, grouped separately and fed with the drug. Animals were sacrificed and the samples were analyzed. The antioxidant enzyme levels of the animals regained and markedly increased in the acute and chronic immobilized groups, respectively. The results suggested that the extract of C. paniculatus seed was highly efficacious in reducing the stress induced by least mobility for hours.

Impairment of spermatogenesis in rats by mercuric chloride: involvement of low 17β-estradiol level in induction of acute oxidative stress

Mercuric chloride (HgCl(2)) has been shown to affect the male reproductive organs, and oxidative stress has been linked with hypospermatogenesis and with male infertility. However, the specific mode of impairment of spermatogenesis during HgCl(2) exposure has not yet been clarified fully. Because of the involvement of 17β-estradiol (E2) in the male reproductive tract and its putative role on spermatogenesis, the present study aimed to investigate the possibility that HgCl(2)-induced oxidative stress-mediated modulation of the E2 level exerts adverse effects on testicular steroidogenic and gametogenic activities. HgCl(2) treatment at 50 and 100 ppm for 90 days by continuous oral administration in the drink water resulted in significant dose-dependent fashion decrease in serum and testicular E(2) levels and an increase in testicular testosterone levels in dose-dependent manner, without statistical alteration in serum testosterone level among HgCl(2) exposed groups compared to the control. Cauda epididymal sperm count and motility were decreased significantly (p < 0.01), in a dose-dependent manner, in the HgCl(2)-treated groups, and qualitative examination revealed inhibition of spermatogenesis and the preferential loss of maturing and elongated spermatids. The seminiferous tubules were dilated in treated animals. When compared to the control, increase in lipid peroxidation due to toxic effects of HgCl2 was accompanied by significant reduction (p < 0.01) in antioxidant enzymes activities, superoxide dismutase, catalase, and glutathione peroxidase of testes, implicating the presence of oxidative tissue damage. Furthermore, these tissue injuries caused functional impairment as evidenced with testicular elevated activity of lactate dehydrogenase. Unless oxidative stress can lead to cancer development, testis' tumor markers as beta human chorionic gonadotropin and alpha-fetoprotein levels have shown no significant differences in the HgCl(2)-exposed group compared with respect to the control. Large quantities of metal accumulated in the testis tissue are in agreement with the testis-activity failure verified in this tissue. These findings suggest that a decrease in E2 level after mercury exposure may render testis more susceptible to oxidative damage leading to its functional inactivation, thus providing new dimension to mechanisms underlying heavy metal-induced male infertility.

Correlation of testicular toxicity and oxidative stress induced by chlorpyrifos in rats

Effect of chlorpyrifos pesticide on testicular oxidative damage was studied in Sprague-Dawley rats at varying doses. At lower doses (5 and 10 mg/kg body weight/30 days), reduction in plasma levels of testosterone and follicular stimulating hormone (FSH) and luteinizing hormone (LH) along with significant shrinkage of seminiferous tubules and drastic changes in germ cells were seen. But these adverse changes of testes were restored with the revival of serum testosterone and FSH and LH at higher doses (20 and 30 mg/kg body weight/30 days). Similarly, levels of testicular lipid peroxidation and diene conjugates were elevated whereas activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), steroidogenic (Δ5, 3β-HSD and Δ5, 17β-HSD) enzymes and angiotensinogen-converting enzyme and glutathione content including lipid–protein content of testes were decreased at low doses. But at higher doses, reductions in level of lipid peroxidation (as revealed by malondialdehyde [MDA] value) and conjugated dienes were found and on the contrary, revivals of testicular antiperoxidative/antioxidant enzymes defense systems, angiotensinogen-converting enzyme (ACE), steroidogenic enzymes, lipid–protein and antioxidant glutathione content were observed. Therefore, the present study indicated from the results that chlorpyrifos had a dual effect at both doses on oxidative stress changes, but at higher doses, the cells were triggering its natural defense mechanism to combat the insult of lower doses of chlorpyrifos and became operative possibly through corrective measure of antioxidant enzymes defense system and pituitary gonadotropins hormones feedback mechanisms on testes.

Evaluation of genome damage and its relation to oxidative stress induced by glyphosate in human lymphocytes in vitro

In the present study we evaluated the genotoxic and oxidative potential of glyphosate on human lymphocytes at concentrations likely to be encountered in residential and occupational exposure. Testing was done with and without metabolic activation (S9). Ferric-reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and the hOGG1 modified comet assay were used to measure glyphosate's oxidative potential and its impact on DNA. Genotoxicity was evaluated by alkaline comet and analysis of micronuclei and other nuclear instabilities applying centromere probes. The alkaline comet assay showed significantly increased tail length (20.39 microm) and intensity (2.19%) for 580 microg/ml, and increased tail intensity (1.88%) at 92.8 microg/ml, compared to control values of 18.15 mum for tail length and 1.14% for tail intensity. With S9, tail length was significantly increased for all concentrations tested: 3.5, 92.8, and 580 microg/ml. Using the hOGG1 comet assay, a significant increase in tail intensity was observed at 2.91 microg/ml with S9 and 580 microg/ml without S9. Without S9, the frequency of micronuclei, nuclear buds and nucleoplasmic bridges slightly increased at concentrations 3.5 microg/ml and higher. The presence of S9 significantly elevated the frequency of nuclear instabilities only for 580 microg/ml. FRAP values slightly increased only at 580 microg/ml regardless of metabolic activation, while TBARS values increased significantly. Since for any of the assays applied, no clear dose-dependent effect was observed, it indicates that glyphosate in concentrations relevant to human exposure do not pose significant health risk.

Testicular toxicity in cannabis extract treated mice: association with oxidative stress and role of antioxidant enzyme systems

Intraperitoneal injection of cannabis extract at low doses (total doses ranging from 40 mg to 60 mg per mouse) induced adverse effect on testes and oxidative stress. At low doses, there was a significant increase in lipid peroxidation and decrease in testicular lipid content, but the effects were significantly less at higher doses and at the withdrawal of cannabis treatment (recovery dose). There was a marked decrease in antioxidant enzyme profiles (superoxide dismutase, catalase and glutathione peroxidase) and glutathione content at low doses, but these effects were higher at higher dose and at withdrawal of the treatment (recovery effect). Histology revealed significant shrinkage of tubular diameter and detrimental changes in seminiferous epithelium of testis with resulting lowered serum testosterone and pituitary gonadotropins (follicular stimulating [FSH] and luteinizing hormones [LH]) levels at low doses. But at higher doses and particularly at withdrawal of the treatment, regression of various germ cell layers of testes through the revival of testosterone hormone and pituitary gonadotropins (FSH and LH) were observed, indicating that recovery effects on testes became operative possibly through the corrective measure of endogenous testicular antioxidant enzymes profiles and pituitary gonadotropins hormones feedback mechanisms.

Effect of exogenous L-ornithine L-aspartate on ethanol induced testicular injury in Wistar rats

To investigate reversibility of ethanol induced testicular injuries on treatment with L-ornithine-L-aspartate, male Wistar rats were treated with ethanol (1.6g/kg b.wt/day) and L-ornithine- L-aspartate (200mg/kg b.wt/ day) for 4 weeks. L-ornithine-L-aspartate effectively prevented the ethanol induced body and testes weight reduction; changes in testicular weight well correlated with body weight. Drug exhibited an ability to counteract ethanol induced oxidative challenge as it effectively reduced testicular TBARS and increased tissue ascorbic acid, GSH and activities of superoxide dismutase, catalase, GSH-Red and Se-GSH-Px. However the drug didn't show promising effect on inhibitory effect of ethanol on testicular D5, 3-beta and 17-beta HSD (hydroxy steroid dehydrogenase).

Protection of cyclophosphamide-induced toxicity in reproductive tract histology, sperm characteristics, and DNA damage by an herbal source; evidence for role of free-radical toxic stress

Cyclophosphamide (CP) as an anticancer alkylating agent has been known as a male reproductive tract toxicant. The aim of this study was to examine whether Satureja khuzestanica essential oil (SKEO) as an established herbal antioxidant, might protect tract rat reproductive system from toxicity of CP. To reach this aim, total antioxidant power (TAP) and lipid peroxidation (LPO) in testis and plasma, blood levels of sex hormones, sperm characteristics, DNA integrity and chromatin quality, and fertility in male rats were tested. Histopathological analysis of testes and epididymides and staining of mast cells were performed for assessment of spermatogenic disorders. CP (6 mg/kg/day) and SKEO (225 mg/kg/day) were administered alone or in combination by gavage for 28 days. In the CP-exposed rats, testicular and plasma LPO increased, TAP decreased, plasma testosterone diminished, and both spermatogenesis and fertility were impaired. In CP-treated rats, a decrease in sperm quality was associated with increased DNA damage and decreased chromatin quality. Coadministration of SKEO significantly improved CP-induced changes in plasma testosterone, sperm quality, spermatogenesis and fertility, toxic stress, and DNA damage. It is concluded that CP-induced toxic effects on androgenesis and spermatogenesis is mediated by free radicals. SKEO protects reproductive system from toxicity of CP through its antioxidant potential and androgenic activity.

Protective effect of sodium selenite and zinc sulfate on intensive swimming-induced testicular gamatogenic and steroidogenic disorders in mature male rats

To investigate the ameliorative potential of sodium selenite and zinc sulfate on intensive-swimming-induced testicular disorders, 48 Wistar male rats (age, 4 months; mass, 146.2 ± 3.6 g) were randomly divided into 4 groups: the unexercised-control group (n = 12); the exercised group (n = 12); the control supplemented group (n = 12); and the exercised supplemented group (n = 12). For 10 weeks, the exercised rats underwent a protocol that consisted of 4 h·d–1swimming, for 6 d·week–1; the control rats did not exercise. For 10 weeks, both the supplemented groups received an oral daily dose of a combination of sodium selenite and zinc sulfate (6  and 3 mg·kg body mass–1, respectively). After 10 weeks, a significant reduction (p < 0.05) was seen in rats in the exercised group, compared with rats in both control groups, in paired testicular masses; in epididymal sperm count; in testicular Δ5, 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD; in plasma levels of testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin; in the numbers of preleptotine spermatocytes, midpachytene spermatocytes, and stage 7 spermatids of the stage VII seminiferous epithelium cycle; and in fertility performance. As well, a significant increase (p < 0.05) was seen in the exercised group, compared with both control groups, in plasma corticosterone levels and in testicular content of malondialdehyde and catalase activity. At the same time, there was a significant reduction (p < 0.05) in the exercised group, compared with both control groups, in plasma concentrations of zinc and selenium; in the testicular content of glutathione (GSH), the glutathione and glutathione disulphide (GSSG) ratio, ascorbic acid, and α-tocopherol; and in testicular activities of superoxide dismutase, glutathione-peroxidase, and glutathione-S-transferase in the testes. No significant changes were seen in the number of spermatogonia-A from the stage VII seminiferous epithelium cycle or the testicular content of GSSG among the groups. Sodium selenite and zinc sulfate supplementation significantly protected against exercise-induced testicular gamatogenic and spermatogenic disorders, prevented testicular oxidative stress, and increased antioxidant status. It can be concluded that intensive-swimming-induced oxidative stress causes dysfunctions in the male reproductive system, which can be protected by the coadministration of sodium selenite and zinc sulfate.

Organophosphorus pesticide exposure decreases sperm quality: association between sperm parameters and urinary pesticide levels

Several studies have suggested that human semen quality has declined over the past decades and some of them have associated it with occupational exposure to pesticides. However, most of these studies have not been associated with a reliable exposure level and have been designed mostly as cross-sectional studies. The present work evaluates, in a longitudinal follow-up study, the effect of organophosphate pesticides (OP) at three occupational exposure levels on semen quality. In addition, the study examined the association between OP urinary levels and sperm parameters in exposed and unexposed workers. A total of 139 semen samples from 52 volunteers were assessed. Urinary OP levels were measured by gas-liquid chromatography. The results revealed that the poorest semen quality was found among the subjects with the highest OP exposure and the highest urinary OP levels. Seasonal variations in sperm concentration and sperm count were registered. The results showed a significant decrease in total sperm count among subjects with the highest exposure to OP. Further studies assessing the effects of OP on male reproductive health should be controlled by the variability in human sperm parameters, sperm seasonality, spermatogenesis time and the changing OP exposure level in men highly exposed to OP.

Reproductive Toxicity Evaluation of Pestban Insecticide Exposure in Male and Female Rats

Sexually mature male and female rats were orally intubated with the organophosphorus insecticide, Pestban at a daily dosage of 7.45 or 3.72 mg/kg bwt, equivalent to 1/20 and 1/40 LD50, respectively. Male rats were exposed for 70 days, while the female rats were exposed for 14 days, premating, during mating and throughout the whole length of gestation and lactation periods till weaning. The results showed depressed acetylcholinesterase (AChE) activity in the brain of parents, fetuses and their placentae in a dose-dependent manner. The fertility was significantly reduced with increasing the dose in both treated groups, with more pronounced suppressive effects in the male treated group. The number of implantation sites and viable fetuses were significantly reduced in pregnant females of both treated groups. However, the number of resorptions, dead fetuses, and pre-and postimplantation losses were significantly increased. The incidence of resorptions was more pronounced in treated female compared to male group and was dose dependant. The behavioral responses as well as fetal survival and viability indices were altered in both treated groups during the lactation period. The incidence of these effects was more pronounced in the treated female group and occurred in a dose-related manner. The recorded morphological, visceral, and skeletal anomalies were significantly increased with increasing the dose in fetuses of both treated groups, with more pronounced effects on fetuses of treated females. In conclusion, the exposure of adult male and female rats to Pestban would cause adverse effects on fertility and reproduction.