mahmoud ghazi khansari

Climate change and hot processes in the workplaces has led to an increase in the effects of heat stress on employed people, which has become a major concern, especially in tropical and subtropical countries. Early detection of biomarkers in induction of heat stress-related DNA damage can be used in the identification and evaluation of health and safety, including occupational health professionals, as well as to prevent serious diseases caused by heat stress in various occupations with the nature of hot processes or to help different warm seasons of the year. Therefore, this review study was conducted to identify diagnostic biomarkers heat stress induced- DNA damage in occupational exposure.

Databases such as PubMed, Scopus, Google Scholar, and Web of Science were systematically searched to meet the study’s goals. Moreover, references to relevant publications were examined. Finally, suitable articles were selected and analyzed using the inclusion (studies on different occupations, different biomarkers in hot work environments, all articles published without time limit until the end of April 2022 , and English and Persian language)  and exclusion criteria.

The results of search in databases showed that 9234 articles were found in the initial search. After removing duplicate and unrelated articles, 2209 eligible articles were selected. Based on abstract full-text screening, 7166 studies were excluded, and based on abstract full-text screening, 21 studies were not accessible. Finally, seven articles were selected to be reviewed. The evidence showed that diagnostic biomarkers included the measurement of 8-hydroxy-2-deoxyguanosine (8-OHdG), micronuclei semen quality, heat shock proteins (HSP70), and leukocytes were extracted to heat stress induced- DNA damage in occupational exposure.

Based on a review of studies,  biomarkers identified are suitable for heat stress induced- DNA damage as a result of occupational exposure to extremely high heat climate conditions. Understanding and identifying appropriate biomarkers in inducing DNA damage can help health and safety professionals determine the amount and magnitude of heat stress responses in occupational exposure to different temperatures and take appropriate measures and interventions to control and reduce the hazard effects of thermal stress. This study can also be considered as a preliminary study for research in the future.

Although aluminum oxide nanoparticles (Al2O3-NPs) are the most widely used nanomaterials, limited studies have been reported on their toxicology. Therefore, the present study aimed to investigate the potential toxicity of aluminum oxide (alumina) nanoparticles and the protective role of aqueous extract of wormwood plant on nanomaterial-induced disorders in the lung of rats.

Here, 36 male Wistar rats were randomly divided into six groups. Next, the rats were first exposed to 200 mg/kg of the aqueous extract of wormwood plant (by gavage) for 15 days and then received a dose of 30 mg/kg of aluminum oxide nanoparticles as an intraperitoneal injection for 14 days. Furthermore, various features of clinical signs, body weight, biochemical parameters, gene expression changes, lung weight ratio, histopathological observations, and metal content in lung tissue were evaluated during the experiment. Eventually, the ANOVA (Analysis of Variance) and Tukey’s range test were employed to analyze and compare the mean of the data.

The results revealed that aluminum oxide nanoparticles at a concentration of 30 mg/kg body weight led to changes in antioxidant enzyme activities, e.g., T-SOD, CAT, GPx, and TAC, lipid peroxidation, and iNOS for exposed rats. Also, the above biochemical disorders were associated with altered expression of oxidative stress-related genes (HO-1, MT-1) and histological changes in the lung tissue. On the other hand, simultaneous intake of aqueous extract of wormwood plant and aluminum oxide nanoparticles in rats significantly improved the studied parameters (p <0.05).

Our findings showed that the γ-Al2O3 NPs were more toxic than α-Al2O3 NPs, which can be attributed to changes related to their size and shape characteristics. Also, it was observed that the wormwood plant could play a protective role against aluminum oxide nanoparticles-induced pulmonary toxicity in rats.

Epileptic seizure is phenomenon of abnormal synchronous neuronal discharge of a set of neurons in brain as a result of neuronal excitation. Evidence shows the nitric oxide (NO) involvement in neuronal excitability. Moreover, the role of NO-mediated cyclic guanosine monophosphate (cGMP) activation in seizure pathogenesis is well-established. Sumatriptan is a selective agonist of 5-Hydroxytryptamine1B/D auto-receptor, has been reassessed for its neuroprotection. This study was aimed to explore the anticonvulsant effect of sumatriptan through possible involvement of NO-cGMP pathway in mice. For this purpose, the protective effect of sumatriptan on PTZ-induced clonic seizure threshold (CST) was measured using NO-cGMP pathway inhibitors including N(G)-nitro-L-arginine (L-NNA, 1, 5, and 10 mg/kg), 7-nitroindazole (7-NI, 30, 45, and 60 mg/kg), aminoguanidine (AG, 30, 50, and 100 mg/kg), methylene blue (MB, 0.1, 0.5, and 1 mg/kg) and sildenafil (5, 10, and 20 mg/kg). The involvement of nitrergic system was further confirmed by measurement of nitrite levels by Griess reaction. The gene expression of neuronal nitric oxide synthase (nNOS) and subunits of soluble guanylyl cyclase (sGC) was studied using qRT-PCR analysis. Acute administration of sumatriptan (1.2 and 0.3 mg/kg) in combination with subeffective doses of NOS, sGC, and phosphodiesterase 5 inhibitors significantly reversed the PTZ-induced CST (P≤0.001). The nitrite level in prefrontal cortex was significantly attenuated by sumatriptan (P≤0.01). Furthermore, sumatriptan downregulated the PTZ-induced mRNA expression of nNOS, and α1, α2, and β1 genes in cerebral cortex of mice (P≤0.0001). In conclusion, the anticonvulsant activity of sumatriptan at least, in part, is mediated through inhibiting NO-cGMP pathway.

Malathion is an organophosphorous insecticide widely used in agriculture, residential area and public health programs with a known mechanism of toxicity of inhibition of acetylcholinesterase and induction of oxidative stress. Gold nanoparticles (AuNPs) represent a stable and easily synthesized nanoparticles with extensive use in consumer products and medicine. Due to antioxidant property of AuNPs, it is possible that AuNPs may prevent malathion-induced oxidative damage. In this study, the cytotoxicity of malathion and AuNPs (10 and 20 nm) were measured separately in Caco-2 cells. Then the protective effects of AuNPs were evaluated by measuring the oxidative stress (lipid peroxidation level and glutathione content), and acetylcholinesterase activity. The calculated IC50s values at 48 hr were 326.8±0.32, 43.09±0.65, and 41.46±0.24 µg/ml for malathion, AuNPs 10 and 20 nm respectively. Then, the lowest concentration of AuNPs (1 µg/ml) and IC50 concentration of malathion (326.8 µg/ml) were selected to evaluate the effects of pretreatment of Caco-2 cells with AuNPs before exposure to malathion were evaluated. Interestingly, the results showed remarkably significant protective effects of AuNPs by attenuation the different parameters of oxidative stress and cytotoxicity induced by malathion in cells (p<0.001). It is the first report showing protective effects of AuNPs against malathion-induced cytotoxicity in Caco-2 cell line.

Deltamethrin is one of the major pesticides used in agriculture to control pests. Oxidative stress is one of the deltamethrin toxicity mechanisms. Different antioxidants have been investigated to deal with the oxidative damage of toxic substances. The purpose of this study was to evaluate the protective effect of Salvia officinalis extract against deltamethrin-induced hepatotoxicity in rats.

In an experimental study, 30 Wistar rats weighing 200-220 g were randomly divided into 5 groups (n=6 per group); group I was the control, group II received deltamethrin (15 mg/kg), group III received both deltamethrin (15 mg/kg) and  S. officinalis extract (100 mg/kg), group IV received both deltamethrin (15 mg/kg) and S. officinalis extract (200 mg/kg), and group V received merely S. officinalis extract. After 30 consecutive days, liver tissues were evaluated for the levels of malondialdehyde and glutathione peroxidase levels and histopathological changes.

According to findings, Salvia extract could considerably reduce malondialdehyde levels, improve the glutathione peroxidase activity, and reduce the liver damage caused by deltamethrin.

S. officinalis extract showed antioxidant properties and reduced the toxic effects of deltamethrin, so, it can be used as a strong antioxidant in preventing and improving the effects of deltamethrin.

This study aimed to investigate the anti-Acanthamoeba effects of the most used marketed disinfecting solutions in Iran. Moreover, the efficacy of some nano-compounds was tested against pathogenic Acanthamoeba.
The present study was conducted in the School of Public Health, Tehran University of Medical sciences, Tehran, Iran during 2015-2016. Cysts of Acanthamoeba T4 genotype (7 x 104 /ml) mixed at the equal volume with contact lens solutions including Opti-free, Ginza, ReNu, Maxima, Light, and Cyclean for the recommended time by the manufacturers. Nano-silver and nano-gold compounds were also treated with the amoebae. Chlorhexidine 0.02% and normal saline were used as positive and negative controls, respectively. Dead and alive amoebae were determined using vital stain and suspension was cultured in non-nutrient agar. The entire process was repeated at least three times.
In none of the solutions in the manufacturer's brochure recommended time, full cytotoxic effect was observed on the cysts of Acanthamoeba. Opti free express solution destroyed the cysts after 6 days. Nanosilver and nano-gold compounds showed no cytotoxic effect on the cysts of Acanthamoeba.
None of the Nanoparticles compounds as well as contact lenses disinfecting solutions which studied was effective on Acanthamoeba cysts in the manufacturer's brochure recommended time. However, continuing study on Nano-silver and Nano-gold compounds to find effective ingredients against Acanthamoeba are highly recommended.

Aflatoxin B-1 (AFB1) is one of the major mycotoxins causing food contamination. Previous studies have shown that AFB1 can induce carcinogenicity and toxic effects in the isolated perfused rat liver and these effects are associated with its metabolites and peroxidation activity. Here we surveyed whether these pathogenic effects of AFB1 are associated with TNF-α as an inflammatory cytokine in general liver damages. In this study, we used twenty male Wistar rats (250-300 g). Rats were divided into four groups. Control group was pre-treated with LPS and then perfused with KHBB. The second group was pretreated with PTX and LPS and then perfused with KHB. The third group was pre-treated with LPS and then perfused with AFB-1 and KHB. The last group was pretreated with LPS and PTX and then perfused with AFB1 and KHB. Results revealed that aflatoxin B1 significantly increased the enzyme activity of aminotransferase and levels of lipid peroxidation. Also, the levels of Glutathione decreased in the aflatoxin group significantly. TNF-α released in perfusate and increased in aflatoxin B1 group significantly and decreased in AFB-1㴵. Exposure to Aflatoxin B1 may induce reactive oxygen species, so these species may induce overproduction of proinflammatory cytokines such as TNF-α and may cause more damage to hepatic cells.

Rapamycin is an immunosuppressant compound with a broad spectrum of pharmaco-logical activities. In recent years, it has been used successfully to decrease ischemia-reperfusion injury in several organ systems. The purpose of the present study was to examine the effect of rapamycin on testicular ischemia-reperfusion injury.
Seventy-two adult male Wistar rats were divided into six groups: control (group1), sham-operated (Group2), T/D DMSO as vehicle group (group3), and groups 4–6; respectively received 0.5, 1, and 1.5 mgkg-1 of rapamycin , IP 30 min before detorsion. Ischemia was achieved by twisting the right testis 720o clockwise for 1 hr. The right testis of 6 animals from each group were excised 4 hr after detorsion for the measurement of lipid peroxidation, caspase-3, and antioxidant enzyme activities. Histopathological changes and germ cell apoptosis were determined by measuring mean of seminiferous tubules diameters (MSTD) and TUNEL test in right testis of 6 animals per group, 24 hr after detorsion.
Testicular T/D caused increases in the apoptosis, malondialdehyde (MDA), and caspase-3 levels and decreases in the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in ipsilateral testis (P Rapamycin administration during testicular torsion decreased ischemia/reperfusion (I/R) cellular damage.

Scorpion venom toxicity is one of the major medical concerns from old years, due to its influence on human activities and health. From many years ago a lot of researches established to examine different aspects of venom toxicity and its effects on different organs. During these years researchers are doing more specific studies on the cytotoxicity of scorpion venom. In Iran, Odonthobuthus doriae, the yellow scorpion is one of the major threats based on its neuro toxicity and severe pathophysiologic effects and researchers tried to find the mechanism of these neuro toxic effects. The previous studies have shown that in isolated organs the yellow scorpion venom is affecting the ion channels. Also some studies showed that this venom has severe cytotoxic effects on the cell lines with many ion channels like nerve cell lines.
In this study the cytotoxic effect of the crude venom of O.doriae on the 1321N1 cell line (cancerous nerve cells). primary cell cultured investigated in the presence of different ion channel blockers: Ouabain (1mmol as Na channel blocker), Verapamil (10μmol/l as Ca channel blocker), TEA (40mmol as K channel blocker) by MTT method. The result showed that the O.doriae crude venom has cytotoxic effect via Na channels.

Objective (s):Hyperglycemia is widely recognized as the underlying cause for some debilitating conditions in diabetic patients. The role of cannabinoid CB1 and vanilloid TRPV1 receptors and their endogenous agonists, endovanilloids, in diabetic neuropathy is shown in many studies. Here we have used PC12 cell line to investigate the possible influence of glucose concentration in culture medium on cytoprotective or toxic effects of a CB1 [WIN55 212-2 (WIN)], or TRPV1 [Capsaicin (CAS)] agonist. Cell viability was tested using the MTT assay. We have also measured TRPV1 and CB1 transcripts by real time reverse transcription-polymerase chain reaction while cells were grown in low (5.5 mM) and high (50 mM) glucose concentrations. Real time PCR results indicated that high glucose medium increased (P<0.01) TRPV1 mRNA and decreased (P <0.001) that of CB1. Cell culture tests show that hyperglycemic cells are more vulnerable (Dose × Medium, F (3,63)=41.5, P<0.001) to the toxic effects of capsaicin compared to those grown in low glucose medium. These findings propose that hyperglycemic conditions may result in neuronal cell death because of inducing a counterbalance between cytotoxic TRPV1 and cytoprotective CB1 receptors.

In recent years, there has been an increasing amount of study on early diagnosis of kidney injury through sensitive and specific biomarkers. We examined the practical applicability of the urinary levels of NAG (N-acetyl-β-D-glucosaminidase), AP (alkaline phosphatase), and LDH (lactate dehydrogenase) as renal dysfunction screening biomarkers in full and pre-term newborns treated with gentamicin. Fourteen pre-term and fifteen full-term newborns who received gentamicin for suspected infections were enrolled. Serum and urine specimens were obtained before the zero days and after gentamicin infusion on the 1st, 3rd, and 5th days of treatment. In full-term newborns a significant increase in urinary NAG, LDH, AP after 5 days of gentamicin administration compared with control group was noted (P<0.05, PP<0.01; respectively). Our findings indicate that urinary enzymes may be useful in full-term newborns as a non-invasive method for evaluation of tubular function.

Glutathione (GSH) is one of the most important antioxidants that plays an essential role in detoxification of reactive oxygen species (ROS) which oxidizes to glutathione disulfide (GSSG). Paraquat (PQ), awidely used herbicide, causes pulmonary injury with the productionof ROS. Excessive ROS accumulation as a consequence of PQ exposure are frequently targeted by GSH thereby oxidative stress leads to depletion of cellular GSH by transforming of GSH to glutathione disulfide (GSSG). A precise method of measuring of GSSG concentration in plasma as indicator of oxidative stress is needed. Some analytical techniques such as high-performance liquid chromatography (HPLC), gas chromatography and capillary electrophoresis have been used for determination of GSSG concentration. In the present study, a new HPLC method with fluorescence detection based on derivatization of the amine group of glutathione with 9-fluorenylmethyl chloroformate (FMOC-Cl) was developed. Male Wistar albino rats exposed to different doses of PQ (20-60 mg/kg) and control group were used and after protein precipitation, their plasma was subjected to derivatization with FMOC in the presence of borate buffer. The derivatized samples were injected to HPLC system with C18 column, mobile phase consisting of methanol and phosphate buffer, λem= 315 nm, λex = 260 nm. Among all experimental groups, the rats which received 60 mg/kg PQ, showed a significant increase in the amount of oxidized glutathione (GSSG) compared to the control group. In this study, the applied derivatization and HPLC method made it possible to measure small amounts of glutathione in plasma using a precise and sensitive technique.

Heat, chemical and organic pollution are three types of environmental pollution, caused by refinery and petrochemical industries. Problems caused by hear and chemical pollutants are currently resolved to some extent but organic pollution such as Poly Aromatic Hydrocarbons (PAHs) are still considered as important problems of industry and environment.. A laboratory study was carried out to investigate the effects of native bacterial mixed culture (BMC) isolated from mixtures of refinery and petrochemical wastewaters for treatment of wastewaters of refinery and petrochemical industries.. All bacteria were isolated from two refineries and two petrochemical plants of Iran. Several bacterial strains from both kinds of wastewater were mixed and two final stock culture collections (BMCa and BMCb), showed the ability to improve the growth among strains. BMCa was added to the refinery wastewater (activated sludge influent sample) and BMCb was added to petrochemical wastewater (activated sludge influent sample). The effects of continuous and non-continuous aeration at high and low pressures, along with the effects of nutrient addition in the beginning of experiment versus sequential addition at specific time intervals, were studied. Native BMC, when continuous high level aeration was used, decreased chemical oxygen demand (COD) in refinery and petrochemical wastewaters for about 81% and 63%, respectively. Gradual addition of nutrients increased COD removal of refinery and petrochemical wastewaters to 85% and 87%, respectively. Native BMCs from mixture of refineries and petrochemical wastewaters can be an effective method of wastewater treatment of both regional refinery and petrochemical plants. High pressure continuous aeration and gradual nutrient addition to the native BMCs can improve bioremediation of organic wastewater in different industries..

Paraquat is a kind of herbicide which can cause cell damage by producing active radicals. On the other hand، the antioxidant activity of captopril due to its thiol content prevents cell damage caused by active radicals. The aim of this study was to evaluate the inhibitory effect of captopril on paraquat toxicity in G292 cell line.

This study included 4 groups of control، different concentrations of paraquat (2. 5، 5، and 10 mM)، different concentrations of captopril (0. 03، 0. 06، 0. 12، 0. 25، and 0. 5 mM)، and combination of paraquat and captopril with different concentrations. The cells were placed in the well of 96-well tissue culture microplates with the density of 50،000 cells in each well. After 24 hours of incubation، toxicity tests were performed.

Captopril increased the viability of cells in methylthiazol tetrazolium (MTT) assay but it did not have significant effects on nitric oxide production. It could also significantly reduce the cytotoxicity of paraquat.

Although the antioxidant activity of captopril reduced the cytotoxicity of paraquat in G292 cell line، this reduction was not found to be related with nitric oxide production.

Ocular morbidity is widely observed when radiotherapy includes the orbit. Oxidative stress generated by irradiation is responsible for this complication. In different studies, it has been shown that melatonin has antioxidative properties and a radioprotective role. The aim of this study was to evaluate the antioxidant role of melatonin against radiation-induced oxidative injury in rats'' lenses after total cranial irradiation. Thirty-six adult female Sprague-Dawley rats were divided into six groups. Group I was the control group, group II only received total cranial gamma irradiation of 5 Gy, group III was exposed as the second group but at the dose of 8 Gy, group IV received 30 mg/kg melatonin 30 minutes prior to radiation plus total cranial irradiation of 5 Gy plus 5 mg/kg melatonin daily through intraperitoneal injection for ten days after irradiation, group V was treated similar to the fourth group, i.e. received irradiation plus melatonin, but at the dose of 8 Gy, and group VI only received melatonin (30 mg/kg on the first day and 5 mg/kg on the following days). Ten days after irradiation, all rats were sacrificed and their eyes were enucleated to measure the biochemical parameters i.e. malondialdehyde (MDA) and glutathione (GSH). The levels of MDA in rat lenses increased and the levels of glutathione in lenses decreased after gamma ray irradiation but these parameters were still within normal limits in rats that received melatonin. It could be concluded that melatonin is useful in preventing radiation-induced oxidative injury due to its antioxidative and free radical scavenging properties.

The renin-angiotensin system has an important role in hepatic inflammation and fibrosis. Renin-angiotensin system blockade by angiotensin-converting enzyme (ACE) inhibitors provides some protective effects against hepatic fibrogenesis. Captopril as an ACE inhibitor can decrease inflammatory mediators and attenuate hepatic fibrosis in the livers of bile duct ligated (BDL) rats. The present study was conducted to investigate the effects of captopril on cytokine production in hepatic fibrosis induced by a bile duct ligationmodel in rats. Male rats were divided into four groups including; control, shamoperated, BDL, and BDL plus captopril (10 mg/kg/day, orally). After 28 days of treatment,the livers were removed for cytokine analysis. Hepatic interleukin (IL)-10 and tumor necrosis factor (TNF)-α levels were measured. Captopril treatment decreased the hepatic content of the proinflammatory cytokine TNF-α and increased the anti-inflammatorycytokine IL-10. the present study suggests that the protective effect of captoprilon hepatic fibrosis is likely to be mediated by cytokine production.

Paraquat which is used as herbicide, decreases reduced glutathione (GSH) and increases oxidized glutathione (GSSG) via oxidative stress pathway and formation of ROS (Reactive Oxygen Species). High performance liquid chromatography (HPLC) with fluorescence detector is one of the best methods for assessment of glutathione in samples like plasma which contains low level of this substance for evaluation of many of diseases. The purpose of this study was to evaluate the changes of glutathione quantity due to effect of paraquat in rat plasma with the use of HPLC.

In this study the fluorescence substance 9-fluorenylmethylchloroformate(FMOC) was used for derivatization of amine group of glutathione. To do this, the rat obtained plasma, which had been exposed with four doses of paraquat (20, 30, 40, and 60 mg/kg), was mixed with acetonitryl and centrifuged at 5000 rpm for protein precipitation. The supernatant was completely dehydrated in a 40oC water bath under air flow with an air pump. 506l tap water, 50 6lborate buffer 0.5M, pH=9 and 100 6l FMOC 500 6g/ml were added and then was left at room temperature for 15 min for completion of derivatization. After that, 206l of this solution was injected into aHPLC with C18 column, mobile phase methanol: phosphate buffer (60:40 v/v) and ex=260nm, em=315 nm.

According to the obtained results, the amount of oxidized glutathione was increased significantly only in the dose of 60 mg/kg in comparison with the control group (p)

To test whether there is a common site of action for intravenous anaesthetics at the glycine receptor, the effects of binary combinations of thiopentone, pentobarbitone, and methohexitone have been tested on human α1 glycine receptors expressed in Xenopus laevis oocytes using two-electrode voltage-clamp techniques. During this interventional study, recombinant human alpha-1 receptor gene was prepared and the mRNA was injected into cytoplasmic site of Xenopus oocytes. Two-electrod voltage clamp technique used for pharmacological studies of currents of chloride channels (receptors) from the membrane of oocytes. Then, the effect of three barbiturates on currents induced by agonist on the receptors was measured. Thiopentone (5-40mM), and pentobarbitone (25-400mM), (but not methohexitone) potentiated the glycine-induced (50mM) current in a dose-dependent manner, with the maximum potentiation observed to be 220%, and 400%, respectively. In binary combination with thiopentone, or pentobarbitone, methohexitone reduced potentiation compared to that by the individual anesthetics to 180%, and 280%, respectively. Combination of thiopentone and pentobarbitone (50mM) increased potentiation, compared to that by thiopentone alone. Our results indicate that thiopentone and pentobarbitone both act as positive allosteric modulators at the alpha-1 glycine receptor. In contrast, methohexitone has no action alone but acts as a competitive antagonist to thiopentone and pentobarbitone. We suggest that these three intravenous barbiturate anaesthetics share a common site of action at the glycine receptor.