Ya. R. Shalai’s research while affiliated with Lviv University and other places

Previous in vitro studies have demonstrated a pronounced cytotoxic effect of the thiazole derivative N-(5-Benzyl-13-thiazole-2-yl)-35-dimethyl-1-benzofuran-2-carboxami­de (BF1) on tumor cells. Additionally, it has been determined that scavengers of reactive Oxygen species (ROS) significantly reduce the cytotoxic effect of BF1. In this study, the influence of BF1 on the activity of superoxide dismutase (SOD) and catalase (CAT), both normally and in the presence of ascorbic acid, in mouse Nemeth-Kellner lymphoma (NK/Ly) cells has been studied to evaluate the possible role of antioxidant activity during the action of this substance. The experiments were performed using nonlinear male mice weighing 20–30 g. Intraperitoneal inoculation of 10–15 million cancer cells into the mice induced the ascites form of lymphoma. The thiazole derivative (BF1) was dissolved in dimethyl sulfoxide and added to the test samples at 1, 10, and 50 μM final concentrations. Superoxide dismutase (SOD) and catalase (CAT) activities were determined spectrophotometrically in a homogenate of the lymphoma cells after incubation with the drug for 30 minutes. The baseline level of SOD in the lymphoma of the mice was 0.33±0.02 activity units/min×mg protein. BF1 significantly increased the enzyme activity by 35 % and 29 % at concentrations of 10 (p<0.01) and 50 μM (p<0.05), respectively. The baseline level of CAT activity was 4.61±0.17 nmoles H2O2/min×mg protein, and this significantly decreased by 15 % (p<0.05) and 20 % (p<0.01) following the action of the thiazole derivative at a concentration of 10 and 20 μM, respectively. The increase of SOD activity, coupled with a decrease or absence of changes in CAT activity, may be cytotoxic to cancer cells. Simultaneously, upon the addition of ascorbic acid as a scavenger of ROS to the environment, the activities of SOD and CAT did not change under the action of BF1 at any of the investigated concentrations. Therefore, the effect of the thiazole derivative BF1 has been canceled in the presence of ROS scavengers in the environment. This may indicate the dependence of the cytotoxic effect of BF1 on the presence of ROS in tumor cells.

Many chemotherapeutics drugs have low water solubility, which potentially can decrease their anticancer potential. The use of drug delivery systems has proven to be highly effective in addressing the challenges associated with delivering hydrophobic chemotherapy drugs to tumor tissues. However, two major issues that arise in the clinical nanoparticle-based treatment of cancer are hepatotoxicity and suppression of the hematopoietic system, which can limit their medical applicability. As previously established, thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide in complex with polymeric nanocarriers (nanomicelles) based on polyethylene glycol exhibited a greater level of cytotoxicity towards specific tumor cell lines melanoma, glioblastoma, hepatocarcinoma, leukemia, etc. This compound and its complexes with polymeric nanomicelle significantly changed the activity of antioxidant enzymes in lymphoma cells. Therefore, the purpose of this study was to examine the impact of a thiazole derivative with polymeric nanomicelles based on polyethylene glycol on the hepatocytes (liver cells) of mice that had been implanted with Nemet-Kelner lymphoma. The investigated compounds thiazole derivative, polymeric nanomicelle, and combination of thiazole derivative with nanomicelle at a final concentration of 10 μM were added to the liver samples and incubated for 10 min. The activity of antioxidant defense system enzymes such as superoxiddismutase, catalase, glutathionperoxidase was determined in liver homogenate under the action of studied compounds in vitro. It was reported that neither thiazole derivative, nanomicelle, nor their complex changed the activity of antioxidant enzymes in hepatocytes from mice with lymphoma. Thiazole derivative and it complex with nanomicelle had limited negative side effects in the mice with lymphoma. The investigated compounds were not hepatotoxic toward murine liver cells.

The development of a new anticancer drugs targeted at energy metabolism of tumor cells is a promising­ approach for cancer treatment. The aim of our study was to investigate the action of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1) and its complex with PEG based polymeric nanoparticle (PEG-PN) on respiration and mitochondrial membrane potential in murine NK/Ly tumor cells. The rate of oxygen uptake in NK/Ly cells was recorded by a polarographic method using a Clark electrode. The mitochondrial potential relative values were registered using fluorescence TMRM dye. No changes in glucose-fuelled basal respiration or maximal FCCP-stimulated respiration was detected after 15-min incubation of cells with BF1 (10 µM), PEG-PN or BF1 + PEG-PN complex Fluorescent microscopy data showed that BF1 or PEG-PN separately had no effect on the value of mitochondrial membrane potential, while BF1 + PEG-PN complex caused a significant decrease in mitochondrial membrane potential, indicating­ on the decrease of NK/Ly cells viability. Keywords: cell respiration, mitochondrial membrane potential, NK/Ly tumor cells, PEG, polymeric nanoparticles, thiazole derivative

Background. Many types of tumors are sensitive to changes in prooxidant-antioxidant balance. Thus, further studies on reactive oxygen species inducing antitumor drugs that generate oxidative stress-dependent cytotoxic effects are promising. Our previous works showed that thiazole derivatives in combination with polymeric carriers have a pronounced cytotoxic effect on tumor, while not being cytotoxic against pseudo-normal cells in vitro. It was found that thiazole derivatives in complex with PEG-based polymeric carriers affected the antioxidant system of lymphoma cells in vitro. The aim of this work was to study the in vitro effect of the complex of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1) in combination with polymeric carriers poly(VEP-co-GMA)-graft-mPEG (Th1), poly(PEGMA) (Th3) and poly(PEGMA-co-DMM) (Th5) on the level of lipid peroxidation products in NK/Ly cells. Materials and Methods. The experiments were conducted on white wild-type male mice with a grafted NK/Ly lymphoma. Ascites tumor cells were inoculated into mice intraperitoneally. Abdominal drainage with ascites of anesthetized mice was performed with a sterile syringe on the 7th–10th days after inoculation. Investigated compounds BF1, polymeric carriers Th1, Th3, Th5 and combination of BF1 + Th1 (Th2), BF1 + Th3 (Th4) and BF1 + Th5 (Th6) at a final concentration of 10 μM were added to the lymphoma samples and incubated for 10 minutes. The level of lipid peroxidation products, such as lipid hydroperoxides and thiobarbituric acid-positive products) were determined according to the techniques described below. Results. All applied complexes based on thiazole derivative BF1 and PEG-based polymeric carriers at a concentration of 10 μM increased the activity of lipid hydroperoxi­des in the lymphoma cells by 29–36% compared to control. Complexes Th2 and Th6 increased the significance of BF1 influence on lymphoma cells from P

Background. Drug delivery systems (DDS) have demonstrated a significant ability to overcome many of the challenges associated with the delivery of hydrophobic chemotherapeutic compounds to tumor tissues. However, hepatotoxicity and suppression of the hematopoietic system are the key problems in the clinical treatment of cancer by nanoparticle-based DDS that can limit their medical exposure. The aim of this work was to investigate the effect of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1) conjugated with PEG-based polymeric nanoparticles (PEG-PN – Th1) on the hepatocytes and blood hematological parameters of mice with grafted NK/Ly. Materials and Methods. The experiments were conducted on white wild-type male mice with grafted NK/Ly lymphoma. Investigated compounds BF1, PEG-PN Th1, and combination of PEG-PN + BF1 (Th2) at a final concentration of 10 μM were added to the liver samples and incubated for 10 minutes. The level of lipid peroxidation products and the level of antioxidant defense system (AOS) enzymes were determined according to the techniques described below. The cytological parameters of blood were investigated after the treatment of mice with BF1 in concentrations of 10 and 20 mg/kg, PEG-PN (20 mg/kg) and Th2 complex (10 mg/kg). On the 14th day of the experiment, blood was taken from all groups and the number of erythrocytes, leukocytes and leukocyte formula were counted. Results. It was reported that neither BF1, PEG-PN, nor their complex Th2 changed the content of lipid peroxidation products or the level of AOS enzymes in hepatocytes from mice with NK/Ly. BF1 (in concentration 10 mg/kg) and PEG-PN + BF1 complex did not change the level of murine erythrocytes compared to Doxorubicin. All investigated compounds, except free PEG-PN, significantly decreased the NK/Ly-triggered leukocytosis and increased the level of small lymphocytes. The NK/Ly lymphoma development led to an increase in the number of neutrophils, while BF1 and its complex with PEG-PN reduced it significantly. Conclusions. BF1 and PEG-PN + BF1 complex had limited negative side effects in the mice with NK/Ly. The investigated compounds were not hepatotoxic toward murine liver cells. Both BF1 and its complex with PEG-PN did not cause any major side effects on the murine blood cells.

Background. Previous studies have shown a pronounced cytotoxic effect of thiazole derivatives in combination with polymeric carriers on tumor cells. At the same time, the derivatives were not cytotoxic against non-cancerous cells in vitro. It was shown that thiazole derivatives at concentrations of 10 and 50 μM affected the prooxidant and antioxidant systems of lymphoma cells in vitro. The aim of this work was to study the effect of the complex of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1) in combination with polymeric carriers poly(VEP-co-GMA)-graft-mPEG (Th1), poly(PEGMA) (Th3) and poly(PEGMA-co-DMM) (Th5) on the antioxidant defense system of the NK/Ly cell in vitro. Materials and Methods. The experiments were performed on white wild-type male mice with grafted NK/Ly lymphoma. Tumor cells were inoculated into mice intraperitoneally. Ascites was drained from the abdominal cavity of anaesthetized mice with a sterile syringe on the 7th-10th day after inoculation. Investigated compounds BF1, BF1 + Th1 (Th2, Th12), BF1 + Th3 (Th4, Th14), BF1 + Th5 (Th6, Th16) at a final concentration of 10 μM were added to the lymphoma samples and incubated for 10 min; the activity of antioxidant enzymes was determined according to the techniques described previously. Results. It was found that all the studied complexes based on thiazole derivative BF1 and polymeric carriers poly (VEP-co-GMA)-graft-mPEG (Th2, Th12), poly (PEGMA) (Th4, Th14) and poly (PEGMA-co-DMM) (Th6, Th16) at a concentration of 10 μm increased the activity of SOD, while the activity of CAT and GPX were reduced compared to control. Complexes Th2, Th12 and Th4 increased the significance of the BF1 influence on lymphoma cells from P

Thiazole derivatives were shown to have toxic effects in vitro on cancer cells of different origin and can be considered as potentially antineoplastic, but their effect on the normal tissues needs to be studied. In this research the newly synthesized thiazole derivatives of N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzo-furan-2-carboxamide (BF1) and 8-methyl-2-Me-7-[trifluoromethyl-phenylmethyl]-pyrazolo [4,3-e] [1,3] thiazolo [3,2-a] pyrimidin-4 (2H)-one (PP2) were used and their effect on the pro- and antioxidant processes after adding in a 1, 10 and 50 μM concentrations to the liver homogenate of healthy and NK/Ly lymphoma-bearing mice was estimated. The level of superoxide radical and TBA-active products as well as catalase, SOD and glutathione peroxidase activity were measured. It was shown that superoxide radical and TBA-active products­ level and catalase activity were significantly higher in the liver of tumor-bearing mice than in the liver of the healthy mice. Neither BF1 no PP2 influenced the studied indices in the liver homogenate of healthy and tumor-bearing animals with the exception that PP2 significantly reduced the level of TBA-positive products in both cases. The data obtained showed that the studied thiazole derivatives did not cause severe liver toxicity in both healthy and tumor-bearing mice.

Background. A pronounced cytotoxic action of the thiazole derivatives complexed with polymeric carriers on tumor cells in vitro was reported earlier, while no cytotoxicity of these compounds was detected toward noncancerous cells. It was found that thiazole derivatives at concentrations of 10 and 50 µM affected lymphoma cell ultrastructure in vitro. The purpose of this work was to investigate the effect of thiazole derivative 8-methyl-2-Me-7-[trifluoromethyl-phenylmethyl]-pyrazolo-[4,3-e]-[1,3]- thiazolo-[3,2-a]-pyrimidin-4(2H)-one (PP2) and its complexes with polymeric carriers poly(VEP-co-GMA)-graft-mPEG (Th12) and poly(PEGMA) (Th14) on the ultrastructure of lymphoma cells in vivo. Materials and Methods. Experiments were conducted on white wild-type male mice with grafted NK/Ly lymphoma. Ascite tumors were created by intreperitoneal inocu­lation of 1–2 mln of Nemet–Kelner lymphoma cells to mice. On the 12th day after inoculation, the body weight of animals was increased by 140–160 % mostly due to ascites growth. For treatment of ascites three solutions of the chemical compounds were prepared: PP2, PP2 + Th12, PP2 + Th14 and administered to the mice intraperitoneally for 5 days. The final concentration of PP2 was 5 mg/kg of body weight. Abdominal drainage from ascites was performed with a sterile syringe under chloroform anesthesia on the 10th day after the start of treatment. The ultrastructure of the cells was examined by electron microscopy. Results. Еlectron microscopy study showed that control lymphoma cells have a special subcellular formations such as a relatively large nucleus, and specific plasma membrane filaments. The effects of thiazole derivative revealed apoptotic and necrotic manifestations of cytotoxicity, such as a deformation and disintegration of nucleus, a decreased nucleus/cytoplasm ratio, a destruction of the plasma membrane and a change of mitochondria shape. The studied compound complexed with polymeric carriers caused an apoptotic-like changes in lymphoma cells. Under the action of such complexes, the nucleus/cytoplasm ratio decreased and the area of mitochondria increased. Conclusions. The obtained results suggest that the tested compounds induce apoptosis in tumor cells. Complexes of thiazole derivative with polymers do not impair the effect of the compound on lymphoma cells. The obtained data can be used to carry out further preclinical studies of thiazole derivatives complexed with polymeric carriers as potential antitumor drugs.