Aleksey Shchulkin

• Doctor of Medicine
• Ryazan State Medical University

S-nitrosoglutathione (GSNO) is the S-nitrosated derivative of glutathione (GSH). GSNO is an endogenous class of NO donors and a natural NO depot in biological systems. Organic anion transporting polypeptide 1B1 (OATP1B1) is an influx transporter that is expressed in the liver. OATP1B1 plays an important role in the transport of endogenous and exoge...

Objective. To study the effect of Mexidol on the level of factors regulating neuroregenesis. Material and methods. The study was performed on male Wistar rats. Focal cerebral ischemia was reproduced by endovascular occlusion-reperfusion of the right medial cerebral artery. The duration of occlusion was 60 min. During the beginning of reperfusion, t...

Purpose. To study the features of the immunological and free radical status of the cornea in its alkaline burn and the possibility of its correction with lactoferrin. Material and methods. The experimental work was performed on 45 male rabbits of the Soviet Chinchilla breed. The animals were divided into 3 series: norm, modeling of alkaline burn an...

The effect of the nitric oxide donor S-nitrosoglutathione on the level and activity of organic anion transporting polypeptide 1B1 (OATP1B1), as well as the expression of the SLCO1B1 gene encoding the transporter protein, was investigated in HepG2 cells. The study has shown that treatment of cells with S-nitrosoglutathione for 3 h did not influence...

Nitric oxide II (NO) is a signaling molecule that has a wide range of physiological effects, including the regulation of gastrointestinal processes. The liver actively expresses the clinically significant transporters OATP1A2 and OATP1B1, which are involved in the influx of biologically active and medicinal substances. That is why it seems relevant...

Introduction. Parkinson's disease (PD) is a chronic neurodegenerative disease of the central nervous system with accumulation of alpha-synuclein and degeneration of nigrostriatal neurons. A number of studies have shown that one of the links in the pathogenesis of PD may also be microdamage of blood vessels. However, how these changes affect interce...

The mechanisms of regulation of the organic anion transporting polypeptide OATP1B3 by sex hormones were studied using HepG2 cells. Estradiol, progesterone, and testosterone were added to cells at concentrations of 1, 10, 100 μM for 24 h. The relative content of OATP1B3 was evaluated by Western blotting. Estradiol at concentrations of 10 and 100 μM...

Introduction. S-nitrosoglutathione is an S-nitrosylated derivative of glutathione and is considered an important mediator of the signaling effects of ni-tric oxide (II). In turn, nitric oxide can exhibit both regulatory and toxic effects due to the formation of active forms of nitrogen and nitrosylation of in-tracellular components, which can lead...

Effect of succinic acid on the processes of myogenesis was investigated in the study with the cells of C2C12 line. In the concentration range 10-1000 µM, succinic acid stimulated the process of myogenic differentiation, increasing the levels of myogenesis factors MyoD (at all stages of myogenesis) and myogenin (at the stage of terminal differentiat...

In a study on cells of the C2C12 line, the effect of succinic acid on the processes of myogenesis was studied. In the concentration range of 10-1000 microns, succinic acid stimulated the process of myogenic differentiation, increasing the number of myogenesis factors MyoD (at all stages of myogenesis) and myogenin (at the stage of terminal differen...

INTRODUCTION: Currently, investigation of efflux transport systems of an organism is an important scientific and practical task permitting to more deeply investigate the pharmacokinetics of medical drugs and to optimize pharmacotherapy of a number of diseases. The super family of ABC transporters plays a significant role in transport of biobiotics,...

The effectiveness of ethylmethylhydroxypyridine succinate (EMHPS) in acute alcohol intoxication was tested in a study on SPF male outbred ICR mice. Ethanol (concentration 40%) was administered to animals once intraperitoneally at a dose of 4 g/kg. Control animals were injected with saline in an equivalent volume. In 15 min after the administration...

The free radical and cytokine statuses of the cornea during its thermal burn and the possibility of its correction by lactoferrin have been studied in Soviet Chinchilla rabbits. The development of a corneal thermal burn was accompanied by the development of oxidative stress (increased levels of TBA-reactive substances and carbonyl derivatives of pr...

BACKGROUND: Alcohol (ethanol) use disorder is a destructive condition with alterations in impaired energy and metabolic processes and activation of free radical oxidation processes. Therefore, the use of antioxidants in the complex therapy of this pathology is pathogenetically justified, one of which is the original domestic drug ethylmethylhydroxy...

P-glycoprotein (Pgp, ABCB1, MDR1) is an efflux transporter protein that removes molecules from the cells (outflow) into the extracellular space. Pgp plays an important role in pharmacokinetics, ensuring the absorption, distribution, and excretion of drugs and its substrates, as well as in the transport of endogenous molecules (steroid and thyroid h...

In experiments on HepG2 cells, we studied the effect of the original domestic neurotropic drugs omberacetam, fabomotizole, and ethylmethylhydroxypyridine succinate (EMHPS) (1-500 μM) on the activity and content of organic anion transporting polypeptides OATP1B1 and OATP1B3. It was shown that omberacetam (500 μM) increased the content of OATP1B1 and...

INTRODUCTION: C2C12 is an immortalized mouse myoblast cell line actively used as in vitro experimental models to study skeletal muscle metabolism in biomedical research. C2C12 cells can differentiate into myocytes under appropriate culture conditions. It is important to understand the specifics of each stage of myogenesis and its regulatory mechani...

INTRODUCTION: ABCB1 is a membrane transporter protein responsible for efflux of a wide range of drugs from cells. The study of the mechanisms of regulation of the functioning of ABCB1 protein in the brain in its ischemia will permit to propose new approaches to pharmacotherapy of cerebral ischemic pathology. AIM: To study the regulation of ABCB1 pr...

Aim. To evaluate the pharmacokinetics of amlodipine in patients with arterial hypertension. Design. Open cohort study. Materials and methods. The study included 183 patients, 98 of them with uncontrolled arterial hypertension and 85 with controlled hypertension. All patients regularly took any two antihypertensive drugs (AHD) (lisinopril, amlodipin...

The solute carrier organic anion transporter family member OATP1B1 is one of the most important transporter proteins which mediate the penetration of many endogenous substances and xenobiotics into hepatocytes. A model system providing the expression of the functional protein is needed to assess the interaction of OATP1B1 with various substances. B...

Organic anion transporting polypeptide 1B1 (OATP1B1) is an influx transporter protein of the SLC superfamily, expressed mainly in the liver and some tumor cells. The mechanisms of its regulation are being actively studied. In the present study, the effect of sex hormones (estradiol, progesterone and testosterone) on OATP1B1 expression in HepG2 cell...

2-Ethyl-6-methyl-3-hydroxypyridine succinate (EMHPS, Mexidol) is an original antioxidant and an anti-ischemic drug with the possibility of wide applications in the complex therapy of diseases, accompanied by the development of oxidative stress and ischemia; for example, ischemic stroke, chronic cerebral ischemia, and chronic heart failure. The use...

INTRODUCTION: Tobacco smoking is an important medical problem since it has a significant impact on the development and progression of chronic obstructive pulmonary disease (COPD). The components of tobacco smoke can initiate and support local and systemic inflammation with participation of monocytes and macrophages. AIM: To study molecular mechanis...

The solute carrier organic anion transporter family member, OATP1B1, is one of the most important transporter proteins, which mediate penetration of many endogenous substances and xenobiotics into hepatocytes. A model system providing expression of the functional protein is needed to assess interaction of OATP1B1 with various substances. Based on t...

Protein ABCG2 (BCRP, breast cancer resistance protein) is an efflux transmembrane protein involved in the transport of endo- and exogenous substances, as well as in the development of tumor resistance to chemotherapy. In this work, the influence of sex hormones progesterone, estradiol, and testosterone on the relative amount of ABCG2 in Caco-2 cell...

The constitutive androstane receptor (CAR) and the pregnan X receptor (PXR) are nuclear receptors that are involved in the regulation of gene transcription of enzymes responsible for biotransformation and excretion of endo- and xenobiotics. The aim of the study was to study the effect of DL-butyonine sulfoximine (BSO, gamma-glutamylcysteine synthet...

One way to analyze the activity of the ABCB1 protein is to assess the accumulation of its substrate fexofenadine (F.) inside the test cells. The goal is to develop and validate a method for the quantitative analysis of F. in Caco-2 cell lysate using HPLC-MS/MS. Materials and methods. Caco-2 cell lysate was used as a matrix. The analysis was perform...

INTRODUCTION: Use of metal nanoparticles is a promising trend in oncotherapy. AIM: To evaluate cytotoxicity of gold nanoparticles (GNPs) modified with fucose, lactose and galactose residues, on Caco-2 cells. MATERIALS AND METHODS: Cells were cultured to a monolayer with GHPs in concentrations of 10 g/ml600 g/ml for particles with fucose, 10 g/ml900...

INTRODUCTION: Despite the recently established evidence-based and systemic approach to treatment for arterial hypertension (AH), not in all cases its control can be achieved. AIM: To conduct a comparative analysis of the concentration of antihypertensive drugs (AHTDs) in blood serum of patients with controlled and uncontrolled AH. MATERIALS AND MET...

The pharmacokinetics of succinate was studied in Wistar rats after a single intravenous administration of Mexidol in a dose 100 mg/kg body weight. The concentration of succinate in blood plasma, cytoplasmic and mitochondrial fractions of cells of the cerebral cortex, left-ventricular myocardium, and liver was measured by HPLC-MS/MS. After single in...

Introduction. Breast cancer resistance protein (BCRP) is an efflux membrane transporter that controls the pharmacokinetics of a large number of drugs. Its activity may change when taking some endo- and exogenous substances, thus making it a link in drug interactions. Aim. The aim of the study was to develop a method for testing of drugs for belongi...

(1) Background: This study was planned to assess the concentration of antihypertensive drugs (AHD) in the blood serum in patients with controlled and uncontrolled arterial hypertension (AH). (2) Methods: We assessed 46 patients with AH. Based on the results of 24 h blood pressure monitoring (ABPM), the patients were randomized into two groups. The...

Introduction. Rotenone is a neurotoxin that causes damage of dopaminergic neurons in the substantia nigra and is used as a model for experimental parkinsonian syndrome. The development of a technique for the quantitative determination of rotenone in the brain will allow testing new strategies for the pharmacotherapy of parkinsonism by reducing the...

Research justification . Corneal ulcer is a common corneal pathology dangerous because of its complications, which occur in 2.5–37.9 % of cases despite modern treatment. Thus, the development of novel methods improving the results of corneal ulcer treatment is very important. Research objective was to evaluate the efficacy of lactoferrin-based ther...

The level P-glycoprotein (Pgp) in organs of pregnant rabbits and its content and activity in the placental barrier at different stages of pregnancy were studied. An increase in Pgp content in the jejunum on days 7, 14, 21, and 28 of pregnancy in comparison with this parameter non-pregnant females was revealed by ELISA; in the liver, Pgp content was...

In the study on cells of the Caco-2 line, the affiliation of malondialdehyde (MDA) to modulators and substrates of P-glycoprotein (Pgp) was assessed, and the biological role of Pgp in conditions of oxidative stress (OS) was studied. MDA was used at concentrations of 10, 50, 100, and 150 μM; OS was simulated by incubation with hydrogen peroxide (H2O...

Breast cancer resistance protein (BCRP,ABCG2) is an efflux transporter protein that transports various substrates from the cell to the extracellular space or organ cavities. The aim of this study was a complex assessment of the amount of BCRP during pregnancy in rabbits. The amount of BCRP in samples of the rabbit jejunum, liver, kidney, cerebral c...

Statins (β-hydroxy-β-methyl-glutaryl-CoA reductase inhibitors) are the main class of drugs for the treatment of dyslipidemia. To improve the safety of therapy with their use, a test system is needed to assess their penetration into hepatocytes using OATP1B1/OATP1B3 transporter proteins. The aim of the study was to develop a method for assessing the...

Cells of the Caco-2 line have the basic properties of enterocytes of the small intestine, and therefore can be used to study the absorption of medicinal substances. Aim. To characterize the properties of the Caco-2 cell line from the Institute of Cytology of the Russian Academy of Sciences and to evaluate with its help the mechanism of absorption o...

Objective. To study the functioning of ABCB1 protein in pregnancy, namely, to evaluate its amount in the organs that play a significant role in pharmacokinetics and its functional activity at the whole organism level. Materials and methods. The study was performed on 52 female rabbits divided into two groups. Serum concentrations of progesterone, e...

INTRODUCTION: Metoprolol is a selective β1-adrenoblocker without intrinsic sympathomimetic activity. The effectiveness of metoprolol has been proven in numerous clinical studies in the treatment of arterial hypertension, stable angina, myocardial infarction, chronic heart failure. To improve the efficiency and safety of the therapy, it is advisable...

Mitoxantrone is a marker substrate of breast cancer resistance protein (BCRP). BCRP is involved in a number of pharmacokinetic drug–drug interactions. The transporter’s possible saturability makes it advisable to use low concentrations of mitoxantrone for in vitro studies. Consequently, mitoxantrone quantification requires a method with high sensit...

We investigated the mechanisms of P-glycoprotein (P-gp) transporter regulation in Caco-2 cells under exogenous and endogenous oxidative stress (OS). Exogenous OS was modeled by exposure of the growth medium to hydrogen peroxide at concentrations of 0.1, 0.5, and 1 M for 24 h or 10 M for 72 h. Endogenous OS was modeled by incubating cells with DL-bu...

Introduction. Increased functional activity of the P-glycoprotein transporter (ABCB1) in the blood-brain barrier (BBB) is a possible reason why neuroprotective pharmacotherapy is ineffective after ischaemic stroke. Study aim to develop a way to inhibit the functional activity of ABCB1 at the BBB. Materials and methods. The study was performed on 60...

INTRODUCTION: Nuclear factor E2-related factor 2 (Nrf2) is a member of capncollar (CNC) family of subfamily of leucine zipper transcription factors that regulates cell protection against toxic substances and oxidants. AIM: To determine location, mechanism of activation and role of Nrf2 in conditions of oxidative stress in vitro. MATERIALS AND METHO...

Background. P-glycoprotein (Pgp) is a multidrug resistance protein 1 with broad substrate specificity. Its functioning can change under the influence of various substances, so the search for endogenous and exogenous compounds that modulate the activity of the transporter protein is an important area of research. Aim. To evaluate the effect of DL-bu...

INTRODUCTION: Human breast cancer resistance protein (BCRP, ABCG2) is a transport protein of ABC superfamily of transporters that uses ATP energy of for its work. BCRP plays an important role in the pharmacokinetics of drugs, therefore all new drugs are recommended to be tested for belonging to its substrates, inducers and inhibitors. The influence...

The constitutive androstane receptor (CAR) is a nuclear receptor that participates in the regulation of biotransformation of toxic substances and metabolic processes. The mechanisms of expression changes of CAR under conditions of oxidative stress (OS) have not been studied yet and this was the purpose of the study. OS was modeled by incubating Cac...

The effect of endogenous oxidative stress induced by γ-glutamyl cysteinesynthetase inhibitor D,L-buthionine sulfoximine (BSO) on the functioning of hypoxia-induced factor 1α (HIF-1α) was studied on Caco-2 cells. BSO was added for 24 h in concentrations of 5, 10, 50, 100, and 500 μM. It was shown that BSO in concentrations of 10, 50, and 100 μM indu...

A bioanalytical technique for quantitative determination of MDA by HPLC-MS/MS. The proposed method for determining MDA includes the release stage of bound MDA and excludes the derivatization reaction. The lower limit of quantitative detection was 600 nmol/l, the volume of the required sample was 10 µl, the analysis time was 7 min. The range of conc...

INTRODUCTION: Organic anion transporting polypeptide 1B1 (OATP1B1) is a transporter protein that plays an important role in the pharmacokinetics of substances (its substrates), regulating their penetration into hepatocytes. The functional activity of this protein is evaluated by the transport of marker substrates, for example, atorvastatin, on cell...

The functioning and mechanism of P-glycoprotein (Pgp) regulation under conditions of inhibition of glutathione synthesis in human colon adenocarcinoma (Caco-2) cells, which are a model of xenobiotic absorption, were studied in vitro. Glutathione synthesis was inhibited by the action of D,L-buthionine sulfoximine (BSO, an inhibitor of γ-glutamylcyst...

We studied the effect of nitric oxide (NO) on the functioning of P-glycoprotein transporter (Pgp) in Caco-2 cells. NO donor S-nitrosoglutathione (GSNO) was used in concentrations of 1, 10, 50, 100, and 500 μM; the duration of exposure was 24 h. The content of Pgp was analyzed by the Western blotting, activity of the transport protein was analyzed b...

Mechanisms of regulation of the P-glycoprotein (Pgp) transporter under the action of nitric oxide (NO) were studied in Caco-2 cells. S-Nitrosoglutathione (GSNO) was used as a NO donor, which was added to the cells at concentrations 1, 10, 50, 100, and 500 µM and incubated for 3, 24, or 72 h. The amount of Pgp was analyzed using Western blotting, ac...

The aim of the article is to evaluate the ABCB1 protein inhibition in the blood-brain barrier to increase the effectiveness of neuroprotective therapy for focal and global cerebral ischemia. Materials and methods. The work was performed on 103 male Wistar rats. In the 1 st group (n=33), the neuroprotective activity of the ABCB1 protein substrate, n...

Relevance . Ethylmethylhydroxypyridine succinate (EMHPS) is a reference domestic drug with pronounced antioxidant and antihypoxic activity. P-Glycoprotein (Pgp) is an ATP-dependent transport protein localized in tissue barriers and protecting cells and organs from the effects of xenobiotics. Being expressed in the blood-brain barrier (BBB), Pgp lim...

Restenosis of the reconstruction zone is one of the main postoperative complications of vascular reconstructions, which develops in 18–40% of cases and leads to an increase in the risk of limb loss to 20–25%. The search for new markers for predicting the development of this complication is an urgent problem today. Aim of study. To assess the dynami...

The article talks about the effect of nitric oxide (NO) on the functioning of the P-glycoprotein (Pgp) transporter protein in Caco-2 cells. The NO donor is S-nitrosoglutathione (GSNO). When exposed to a specific inhibitor of soluble guanylate cyclase, an increase in the relative amount of Pgp was shown.

The article discusses the mechanisms of regulation of the P-glycoprotein transporter protein (Pgp) in cells of the Caco2 line under conditions of modeling endogenous oxidative stress caused by exposure to DL-butyonine sulfoximine (BSO, a glutathione synthesis inhibitor). Ex-periments have shown that exposure to BSO at concentrations of 10-100 μM le...

The present review considers the main methods for obtaining nanoparticles of precious metals and methods of functionalization of their surfaces. The pharmacokinetics and possible mechanisms of chemotherapeutic action of gold nanoparticles are discussed, including induction of apoptosis, activation of lipid peroxidation, and inhibition of membrane g...

We studied the effect of 3-, 24-, and 72-h exposure to H2O2 in concentrations of 0.1-100.0 μM on the level of constitutive androstane receptor in Caco-2 cells. It was shown that 3- and 24-h incubation with Н2О2 in all concentrations had no effect on the level of constitutive androstane receptors. Increasing the incubation time to 72 h led to an inc...

Relevance. BCRP is an efflux transporter protein that plays an important role in the pharmacokinetics of a wide range of drugs. The BCRP activity in vitro experiments is assessed by the transport of transporter protein substrates (methotrexate, etc.) across the bilipid membrane of cells overexpressingBCRP, for example, Caco-2 cells. The aim is to d...

Pregnan X receptor (PXR) is a nuclear receptor that plays an important role in the regulation of the expression of biotransformation and metabolic enzymes. The functioning and possible mechanisms of PXR regulation under conditions of nitrosative stress have not been studied, which served as the purpose of this study. The work was performed on Caco-...

Aim. To assess the number of markers of apoptosis and cell proliferation, as well as their relationships in the area of restenosis of arterial reconstructions. Methods. The study included 14 patients with a diagnosis of arteriosclerosis obliterans of the lower extremities. Post-thrombotic occlusion of femoropopliteal bypass. All patients were males...

P-glycoprotein (Pgp) is an ATP-dependent transmembrane protein involved in the efflux of lipophilic substances. The aim of this study was to evaluate the effect of oxidative stress on the transport of a Pgp substrate through the monolayer of Caco-2 cells overexpressing this transport protein. Oxidative stress was modeled by incubating the cells wit...

Aim. Determination of the amount of Bcl2 and Bax apoptosis proteins in the homogenate of the vascular wall and blood serum, and of their relationship in patients with obliterating atherosclerosis of the lower limb arteries (OALLA) with III stage of the disease. Materials and Methods. The study included 12 patients with III stage OALLA according to...

The aim of the study was to assess the levels of Всl-2 and Bax proteins in the vascular wall and their correlation with serum cholesterol in patients with stage III-IV atherosclerosis obliterans of lower limb arteries. Materials and methods: The study included 32 patients with stage III-IV atherosclerosis obliterans of the lower limb. Samples of...

Introduction. Despite the development of numerous drugs with neuroprotective activity, their efficacy in cerebrovascular disease remains low, which may partly be due to the efflux function of protein ABCB1 and insufficient penetration of the blood-brain barrier by these drugs. Aim to evaluate the potential to inhibit ABCB1 functional activity in th...

P-Glycoprotein (P-gp) is one of the most clinically significant representatives of the ABC transporter superfamily due to its participation in the transport of biotic components and xenobiotics across the plasma membrane. It is known that various chemicals, environmental factors, and pathological processes can affect P-gp activity and expression. I...

Aim: This study was aimed at determining Bcl-2 and Bax proteins expression before and after reconstructive-repairing operations in patients with atherosclerosis obliterans of lower extremities and at assessing the effect of an antioxidant (vitamin E at a dose of 100 mg once daily for 1 month after surgery) on the dynamics of changes of Bcl-2 and B...

In the review article modern approaches to testing and registration of generic drugs are discussed. The article presents the history of the formation of the methodology for testing generic drugs and the current legislation of the Russian Federation. The stages of confirmation of equivalence of original and generic drugs are described: pharmaceutica...

The article discusses the new role of pregnane X receptor (PXR) under conditions of oxidative and nitrosative stress. The results showed that the effect of hydrogen peroxide and S-nitrosoglu-tathione in high concentrations on Caco-2 cells leads to a decrease in cell viability, which is accompanied by an increase in the amount of PXR. These changes...

The purpose of this work was to study the effect of polysaccharide complexes isolated from tansy flowers (Tanacetum vulgare L., fam. Asteraceae) and melilotus herb (Melilotus officinalis L., fam. Fabaceae) on P-glycoprotein (Pgp, ABCB1 protein) activity in vitro. On Caco-2 cell line the effect of polysaccharide complex isolated from tansy flowers a...

The effects of female sex hormones estradiol and progesterone on P-glycoprotein (Pgp) functioning have been investigated using Caco-2 cells. Pgp activity was analyzed in a transwell system by the transport of its substrate, fexofenadine. The amount of the transporter protein was analyzed by enzyme immunoassay. Incubation of Caco-2 cells with 10 μM...

Under conditions of oxidative stress induced by H2O2 for 72 hours at cincentrations of 50 and 100 mM there is a decrease in survival and transepitelical resistance of cell line Caco-2. The level of oxidized theols increases significantly at the concentration of H2O2 of 10 mM due to easily accessible SH-groups, at 50 and 100 mM H2O2 due to hard-to-r...