Standard solutions of mycotoxins prepared in RP HPLC solvents from neat standards are usually used for analytical method development. Multi-mycotoxin HPLC-MS/MS methods necessitate stability estimation for the wide spectrum of fungal metabolites. The stability of individual diluted stock standard solutions of mycotoxins in RP-HPLC solvents and multi-analyte HPLC-MS/MS calibrants was evaluated under standard storage and analysis conditions. Individual stock standard solutions of aflatoxins, sterigmatocystin, A-and B-trichothecenes, zearalenone and its analogues, ochratoxin A, fumonisins, Alternaria toxins, enniatins and beauvericin, moniliformin, citrinin, mycophenolic, cyclopiazonic acids and citreoviridin were prepared in RP-HPLC solvents and stored at −18 • C for 14 months. UV-spectroscopy was utilized to monitor the stability of analytes, excluding fumonisins. The gradual degradation of α-, β-zearalenol and α-, β-zearalanol in acetonitrile was detected. Aflatoxins and sterigmatocystin, zearalenone, Alternaria toxins, enniatins and beauvericin, citrinin, mycophenolic, cyclopiazonic acids and citreoviridin can be referred to as stable. The concentration of the majority of trichothecenes should be monitored. Diluted multi-mycotoxin standard in water/methanol (50/50 v/v) solutions acidified with 0.1% formic acid proved to be stable in silanized glass at 23 • C exposed to light for at least 75 h (CV ≤ 10%). An unexpected manifestation of MS/MS signal suppression/enhancement was discovered in the course of multi-mycotoxin standard solution stability evaluation. Key Contribution:The stability of the wide spectrum of mycotoxins in individual standard solutions in RP-HPLC solvents and multi-analyte HPLC-MS/MS calibrants under standard storage and analysis conditions is discussed basing on experimental and literature data.

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Non-alcoholic fatty liver disease (NAFLD) is currently estimated as the most prevalent chronic liver disease in all age groups. An increasing body of evidence obtained in experimental and clinical data indicates that oxidative stress is the most important pathogenic factor in the development of NAFLD. The study aimed to investigate the impact of α-lipoic acid (LA), widely used as an antioxidant, on the effects of a hypercaloric choline-deficient diet. Male Wistar rats were divided into three groups: control diet (C); hypercaloric choline-deficient diet (HCCD), and hypercaloric choline-deficient diet with α-lipoic acid (HCCD+LA). Supplementation of HCCD with LA for eight weeks led to a decrease in visceral adipose tissue/body weight ratio, the activity of liver glutathione peroxidase and paraoxonase-1, plasma, and liver total antioxidant activity, as well as an increase in liver/body weight ratio, liver total lipid and triglyceride content, and liver transaminase activities compared to the HCCD group without LA. In conclusion, our study shows that α-lipoic acid detains obesity development but exacerbates the severity of diet-induced oxidative stress and lipid accumulation in the liver of male Wistar rats fed a hypercaloric choline-deficient diet.

Wistar male rats were fed semisynthetic diet with different fat content for 6 weeks: fat-free, 10%, and 30% fat (sunflower oil and lard, 1:1). Increasing fat content was associated with an increase in ethoxyresofurin-O-dealkylase (EROD) activity of CYP1A1, methoxyresofurin-O-dealkylase (MROD) activity of CYP1A2, and 6β-testosterone-hydroxylase (6β-TH) activity of CYP3A1. EROD, MROD, and 6β-TH activities in rats on high-fat diet exceeded those in rats on fat-free diet by 64, 58, and 140%, respectively. Addition of indole-3-carbinol to the diet led to an increase in CYP1A1, CYP1A2, and CYP3A1 activities and mRNA levels, the degree of this increase was lower with increasing fat content in the diet. In rats on fat-free, 10% fat, and 30% fat diets, indole-3-carbinol induced EROD activity by 4.7, 3.2, and 2.0 times, respectively; MROD activity by 5.9, 5.6, and 5.4 times; and 6β-TH activity by 2.1, 1.9, and 1.3 times. A correlation was detected between activities of the studied cytochrome P-450 isoforms, their inducibility by indole-3-carbinol, and vitamin A and E levels in rat liver.

Male Wistar rats received a semisynthetic diet with resveratrol (100 mg/kg), indole-3-carbinol (20 mg/kg), or a mixture of these compounds in the same doses for 1 week. Activities of ethoxyresorufin dealkylase (EROD), methoxyresorufin dealkylase (MROD), pentoxyresorufin dealkylase (PROD), and 6β-testosterone hydroxylase (6β-TH) and the content of mRNA for CYP1A1, CYP1A2, and CYP3A1 were elevated in the liver of rats receiving indole-3-carbinol. These changes were accompanied by an increase in activity of phase II xenobiotic metabolism enzymes (quinone reductase, hemoxygenase-1, glutathione transferase, and UDP glucuronosyl transferase). Resveratrol did not modify activity of these enzymes. After combined treatment with the test compounds, resveratrol suppressed the indole-3-carbinol-induced increase in activities of EROD, MROD, PROD, and 6β-TH, and expression of the corresponding genes. Combined treatment was characterized by potentiation of the antioxidant effects of these compounds.

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ФИЗИОЛОГИЯ И БИОХИМИЯ ПИТАНИЯВ настоящее время в спортивной медицине большое внимание уделяется профилактике и лечению синдрома отсроченной мышечной боли (Delayed onset muscle soreness, DOMS), возникающей через несколько часов или дней после непривычной или интенсивной физической нагрузки, а также состояния перетренированности спортсмена. Одним из основных патогенетических факторов развития данного синдрома является ультраструктурное повреждение миоцитов с активацией процесса апоптоза. В связи с этим особую актуальность приобретает вопрос использования природных антиоксидантов в спортивной нутрициологии для купирования данной патологии. Цель исследования -изучение влияния обогащения рациона антоцианинами на апоптоз миоцитов икроножной мышцы крыс после интенсивной физической нагрузки.Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр питания, биотехнологии и безопасности пищи, 109240, г.

The purpose of the study was to determine how multi-vitamin deficiency affects xenobiotic-metabolizing enzyme (XME) activities in the rat liver. Vitamin levels and XME activities were studied in the livers of male Wistar rats who were fed for 4 weeks with semi-synthetic diets containing either adequate (100 % of recommended vitamin intake) levels of vitamins (control), or decreased vitamin levels (50 % or 20 % of recommended vitamin intake). The study results have shown that moderate vitamin deficiency (50 %) leads to a decrease of vitamin A levels only, and to a slight increase, as compared with the control, in the following enzyme activities: methoxyresorufin O-dealkylase (MROD) activity of CYP1 A2 - by 34 % (p < 0.05), UDP-glucuronosyl transferase - by 26 % (p < 0.05), and quinone reductase - by 55 % (p < 0.05). Profound vitamin deficiency (20 %) led to a decrease of vitamins A, E, B1, B2, and C, and enzyme activities in the liver: MROD - to 78 % of the control level (p < 0.05), 4-nitrophenol hydroxylase - to 74 % (p < 0.05), heme oxygenase-1 - to 83 % (p < 0.05), and quinone reductase - to 60 % (p < 0.05). At the same time, the UDP-glucuronosyl transferase activity and ethoxyresorufin O-dealkylase activity of CYP1A1, pentoxyresorufin O-dealkylase activity of CYP2B1/2 and 6β-testosterone hydroxylase, as well as the total activity of glutathione transferase did not differ from the control levels. The study has demonstrated that profound multi-vitamin deficiency is associated with a decrease in the expression of CYP1A2 and CYP3A1 mRNAs to 62 % and 79 %, respectively. These data indicated that a short-term but profound multi-vitamin deficiency in rats leads to a decrease in the activities and expression of the some XME that play an important role in detoxification of xenobiotics and metabolism of drugs and antioxidant protection.