The role of PGC-1α and metabolic signaling pathway in kidney injury following chronic administration with 3-MCPD as a food processing contaminant.

3-Monochloropropane-1,2-diol (3-MCPD) as a byproduct of food processing and a carcinogenic agent has attracted much attention in the last decades. Kidney is the main target organ that is sensitive to the toxicity of 3-MCPD. Due to limited evidence about possible 3-MCPD toxicity, we design an investigation to determine the role of mitochondrial biogenesis following chronic oral administration of 3-MCPD (2, 4, 8 and 32 mg/kg) for 2 months in male C57 mice. The present study evaluated the affects of 3-MCPD in modulating metabolic signalling which is associated with Il-18, PGC-1α, Nrf-2 and Sir3 which are the major transcription factors. Our data confirms controversial behaviors after chronic exposure with 3-MCPD. Over expression of the PGC-1α and Sir3 and IL-18 were observed after exposure with 2,4 & 8 mg kg-1  day-1 of 3-MCPD. In front, PGC-1α down-regulation occurs at the highest dose (32 mg/kg) resulted in kidney injury. Based on the findings, PGC-1α plays an important role in the restoration of the mitochondrial function during the recovery from chronic kidney injury. We suggest that the PGC-1α can be consider as a therapeutic target in prevention and treatment of kidney injury after chronic exposure of 3-MCPD. PRACTICAL APPLICATIONS: 3-Monochloropropane-1, 2-diol (3-MCPD) existed in several foods, can induce nephrotoxicity, progressive nephropathy and renal tubule dilation following acute and chronic exposure. It revealed that 3-MCPD toxicity is related to metabolites which can cause oxidative stress and activation of cell death signaling. It seems that cytotoxicity of 3-MCPD has disruptive effect on kidney cells due to rise in ROS production and decrease in mitochondrial membrane permeability. These effects can lead to MPT pore opening, cytochrome c release and activation of programed cell death signaling pathway. Therefore, present study was investigated the role of PGC-1a and the metabolic signaling involved in 3-MCPD-induced nephrotoxicity for the first time. Our data revealed that up-regulation of mitochondrial biogenesis following chronic exposure with 3-MCPD accelerates recovery of mitochondrial and cellular function in kidney by deacetylation of histones, overexpression of transcription factors (PGC-1α, Nrf-2, and Sir3) and maintaining cellular homeostasis.

Toxicological assessment of 3-monochloropropane-1,2-diol (3-MCPD) as a main contaminant of foodstuff in three different in vitro models: Involvement of oxidative stress and cell death signaling pathway.

3-Monochloropropane-1,2-diol (3-MCPD) as a main source of food contamination has always been known as a carcinogenic agent. Kidney, liver, testis, and heart seem to be the main target organs for 3-MCPD. Because oxidative stress and mitochondrial dysfunction have been realized to be involved in 3-MCPD-induced cytotoxicity, the present study aimed to investigate the probable toxicity mechanisms of 3-MCPD in isolated mitochondria, HEK-293 cell line, and cell isolated from the rats' liver and kidney through measuring multiparametric oxidative stress assay. Based on the data indicating no significant difference between 3-MCPD-treated groups and control group, metabolites of 3-MCPD have a key role in organ toxicity caused by them. To further investigating the suggested hypothesis, the effect of 3-MCPD toxicity on HEK-293 cell line was examined. Although the proliferation declined after exposure to a low dose of 3-MCPD (10 to 200 µM), controversial responses in higher concentration (2 to 10 mM) have led to studies on the effect of oxidative stress and cell death signaling on isolated kidney and liver cells. Treatment of the isolated kidney and liver cells with 3-MCPD resulted in an increase in the level of reactive oxygen species (ROS), the collapse of mitochondrial membrane potential (MMP), and activation of cell death signaling without creating any significant difference in the amount of reduced glutathione. In fact, 3-MCPD can disrupt the mitochondrial electron transfer in isolated cells, which is correlated with the impairment of mitochondrial oxidative phosphorylation system, the rise of ROS level, and the failure of MMP, leading to the release of cytochrome c from mitochondria to cytosol and finally the activation of cell death signaling.

Health risk assessment of aflatoxin M1 in infant formula milk in IR Iran.

In this study, two accurate, precise, selective and sensitive methods were developed for determining aflatoxin M1 (AFM1) in infant formula milk using immunoaffinity column clean-up followed by high performance liquid chromatography (HPLC) with fluorescence detection. The validated methods were used for determination of AFM1 in 29 samples of 6 different infant formula milk brands and the risk of AFM1 in infants aged zero to 6 months old was assessed using cancer risk, Margin of Exposure (MOE) and Hazard Index (HI). Only one sample (3.4%) was contaminated with AFM1. Although the results showed that MOE values for the mean and median exposure to AFM1 was <10,000 in infants, the additional cancer risk due to mean and median exposure to AFM1 in infant <6 months were 0.00010 and 0.00012 additional cases per year per 105 individuals, respectively, which indicates no health concern. In addition, HI values for the mean and median exposure to AFM1 for infants were quite below one which indicates no health concern. To the best of our knowledge, this is the first report on risk assessment of AFM1 in infant formula milk consumed by Iranian infants <6 months old, presenting a low risk for the evaluated groups.

Quantification of 4-Methylimidazol in NMRI Mice Plasma and Cerebrospinal Fluid (CSF) by Using Liquid Chromatography Tandem Mass Spectrometry.

A sensitive method using ion-pair extraction was developed by liquid chromatography tandem mass spectrometry (LC-MS/MS) for measurement of 4-methylimidazole (4-MI) in NMRI mice plasma and cerebrospinal fluid (CSF). Detection was done by electrospray positive ionization mass spectrometry in the multiple-reaction monitoring (MRM) mode. The validation method was applied to quantification of 4-MI in plasma and CSF samples using oral doses of 100, 200, and 300 mg/kg in NMRI mice. The efficiency of the method was evaluated in terms of linearity (R 2> 0.99), recovery (98-107%, 3 levels) and precision (8-10%, 3 levels, n = 6). Limit of detection (LOD) and limit of quantification (LOQ) were 25 ng/mL and 50 ng/mL, respectively. The results obtained showed that the exposure to oral doses of 4-MI in mice makes different concentrations in plasma and CSF and causes significant changes in mice. This study was the first report for determination of 4-MI in plasma and CSF samples in mice. Our results suggest that LC-MS/MS-based on ion-pair extraction is a robust method with high detection ability for measurement of 4-MI in plasma and CSF samples. Therefore, the developed method can be useful for evaluation and monitoring of imidazole derivatives in biological samples.

Occurrence and Safety Evaluation of Ochratoxin A in Cereal-based Baby Foods Collected from Iranian Retail Market.

Contamination of agricultural commodities with ochratoxin A (OTA) is a worldwide concern in recent decades. Consumption of OTA-contaminated baby foods exerts health implications especially in children as the most vulnerable subpopulations. In the current study, for the first time in Iran, 64 baby foods (rice, wheat, and multigrain) samples from five different brands available in the Iranian market were analyzed to determine OTA level, using a HPLC with fluorescence detector. Overall, OTA was observed in 41% of analyzed samples with a mean and maximum level of 0.42 ± 0.27 and 1.1 µg/kg, respectively. OTA levels in five of 64 samples (7.8 %) were higher than the permissible limit recommended by European Commission (permissible limit: 0.5 µg/kg) and OTA levels in two of 64 samples (3.1%) were higher than the standard set by Iranian standard organization (1 µg/kg). The highest OTA contamination was observed in rice-based baby food cereals (1.1 µg/kg; 57% of the samples), followed by wheat-based (23%) and multigrain (20%) samples. OTA intake in infants (≥9 months old) was more than established provisional tolerable weekly intake by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA) (100 and 120 ng OTA per kg of body weight, respectively). OTA content in baby food and cereals, as well as other raw foodstuff should be investigated comprehensively to reduce the exposure rate of young children to OTA.

High doses of sodium tungstate can promote mitochondrial dysfunction and oxidative stress in isolated mitochondria.

Tungstate (W) is recognized as an agent of environmental pollution and a substitute to depleted uranium. According to some preliminary studies, tungstate toxicity is related to the formation of reactive oxygen species (ROS) under abnormal pathological conditions. The kidneys and liver are the main tungstate accumulation sites and important targets of tungstate toxicity. Since the mitochondrion is the main ROS production site, we evaluated the mechanistic toxicity of tungstate in isolated mitochondria for the first time, following a two-step ultracentrifugation method. Our findings demonstrated that tungstate-induced mitochondrial dysfunction is related to the increased formation of ROS, lipid peroxidation, and potential membrane collapse, correlated with the amelioration of adenosine triphosphate and glutathione contents. The present study indicated that mitochondrial dysfunction was associated with disruptive effects on the mitochondrial respiratory chain and opening of mitochondrial permeability transition (MPT) pores, which is correlated with cytochrome c release. Our findings suggest that high concentrations of tungstate (2 mM)-favored MPT pore opening in the inner membranes of liver and kidney mitochondria of rats. Besides, the results indicated higher tungstate susceptibility in the kidneys, compared with the liver.

Determinations of Melamine Residue in Infant Formula Brands Available in Iran Market Using by HPLC Method.

The contamination of melamine was evaluated in 69 infants along with follow up formula samples collected from the market for the first time in Iran using HPLC method. Since there are no previous data concerning the contamination level of melamine in all brands of infant formula samples consumed using the HPLC method in Iran, this study is the first investigation in this regard. Our results showed that melamine contamination was found in 65% of samples, where mean and maximum levels of melamine were 0.73 ± 0.71 mg/kg and 3.63 mg/kg, respectively. The level of melamine in 10 out of 69 samples was higher than the maximum level set by the Codex Alimentarius in infant food (1 mg/kg). Melamine was determined in 67.8% and 50% of domestic and imported samples, respectively. The estimated daily intake was designed in two scenarios: it was calculated based on the mean level of melamine contamination and maximum level of melamine in the samples. In both scenarios, our results showed that melamine intake across all age groups is lower than the tolerable daily intake (TDI) of 0.2 mg/kg body weight, suggested by WHO (0.2 mg/kg body weight). Thus, it seems that the current levels of melamine in infant and follow up formula purchased in Iran pose no health risk for infants.

Occurrence of Ochratoxin A in Grape Juice of Iran.

Ochratoxin A (OTA) is one of the most important mycotoxins that contaminate a broad range of agricultural and food products. In this study, the occurrence of OTA in available brands of grape juice in Iran purchased from retail outlets or producer were determined for the first time using high-performance liquid chromatography (HPLC) with immunoaffinity columns(IAC) as the clean-up step. The average recoveries for OTA in grape juice ranged from 54.2 to 86.6% with the coefficient of variation lower than 17.3% in lowest spiked level (0.5 µg/L). The estimated LOD and LOQ of OTA were 0.04 µg/L and 0.125 µg/L, respectively. In our study, 70 samples of grape juice evaluated for OTA content. The results showed that in 39 out of 70 samples (55.7%) OTA levels were above the LOQ with the maximum level of 2.6 µg/L and the mean contamination was 0.5 µg/L. Although the mean contamination of OTA in analyzing samples was lower than the MRL set by EU, the high incidence of contamination in these products is worried. Considering the importance of OTA in public health, control of pre- and post-harvest, storage and grape juice manufacturing process, such as HACCP, GAP, and GMP recommended preventive measures are required.

Occurrence of aflatoxin B1 in baby foods marketed in Iran.

BACKGROUND: Aflatoxin B1 (AFB1 ), a toxic fungal metabolite that is found in baby foods, can lead to serious complications for children's health. In the present study, 48 commercial baby foods available in the Iranian market were investigated for the presence of AFB1 using a high performance liquid chromatography system that was equipped with post-column photochemical derivatization and a fluorescence detector. RESULTS: Thirty-three out of 48 samples (68.7%) were contaminated with AFB1 at median, maximum and mean concentration levels of 0.11, 15.15 and 2.602 ± 4.065 µg kg-1 , respectively. The AFB1 concentration in 39.6% of the samples was higher than the maximum level established in Iran for AFB1 within baby foods containing milk (0.5 µg kg-1 ). The incidence of AFB1 in rice, wheat and multigrain infant cereal samples was 90%, 25% and 100%, respectively, whereas rice-based baby foods contained the highest levels of AFB1 . CONCLUSION: In the present study, the finding of both high rates and high levels of AFB1 in cereal baby foods indicates the need to reduce AFB1 contamination in these products. Therefore, further monitoring and control of pre- and post-harvest, storage, and manufacturing processes is required. © 2016 Society of Chemical Industry.

Evaluation of Emerging Fusarium mycotoxins beauvericin, Enniatins, Fusaproliferin and Moniliformin in Domestic Rice in Iran.

The occurrence of emerging Fusarium mycotoxins beauvericin (BEA), enniatins (ENNs) (A, A1, B, B1), Fusaproliferin and moniliformin was evaluated by a liquid chromatography/electrospray ionization-tandem mass spectrometric (LC/ESI-MS/MS) technique in 65 domestic rice samples produced in Gilan and Mazandaran Provinces in Iran. The results showed that 46% of the samples were contaminated with at least one of the emerging mycotoxins. BEA was the most prevalent mycotoxin, which was found in 26 out of 65 rice samples at the concentrations up to 0.47 µg/Kg. Enniatin A1 which was the only member of ENNs was detected in the samples, occurred in 7.7% of samples with an average level of 0.06 µg/Kg. No detectable level of Fusaproliferin and moniliformin was found. This is the first report concerning the contamination of Iranian domestic rice samples with the emerging Fusarium mycotoxins.

A survey of mycotoxins in domestic rice in Iran by liquid chromatography tandem mass spectrometry.

In this study, a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was applied for the simultaneous detection and quantification of a broad spectrum of mycotoxins and fungal metabolites in domestic rice in Iran. A total of 20 fungal metabolites were detected in 65 rice samples. The result showed that all of the samples were contaminated to at least one mycotoxin. The most prevalent fungal metabolites were brevianamide F (81.5%), emodin (46.1%) and tryptophol (43.1%). The occurrence of aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEN) and fumonisin B1 (FB1) was 21.5%, 4.6%, 29.2% and 9.2%, respectively. No detectable level of deoxynivelenol was found in any of the samples. The mean level of regulated mycotoxins was lower than the maximum limit. Co-occurrence of AF1-ZEN, ZEN-OTA and FB1-ZEN were observed in 4.6%, 3.1% and 4.6% of samples, respectively. This is the first report indicating the contamination of domestic rice in Iran with mycotoxins such as alternaria metabolites, citrinin, tryptophol and kojic acid.