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1

Quercetin influences BSA alpha-helical structures of native, ACR- and NaNO2-modified BSAs

100%

Rorbach-Dolata A., Żurawska-Płaksej E., Piwowar A.

Acta Poloniae Pharmaceutica - Drug Research

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2018

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vol. 75

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issue 6

1339-1346

EN

Quercetin (QUE) is a plant flavonoid with a multifarious spectrum of properties. It is a prominent component of the human diet, considered to be safe and beneficial for human health. Acrylamide (ACR) and sodium nitrate III (NaNO2) are also present in the diet and may demonstrate adverse and toxic effects on the macromolecules and tissues of the human organism. Albumin, the most abundant blood protein, is the most susceptible to the action of various exogenous factors, which may lead to structural damage and functional disturbances. The aim of this study was to estimate ACR- and NaNO2-induced changes in the secondary structure of bovine serum albumin (BSA), using circular dichroism (CD), and to determine the impact of quercetin on these modifications. BSA was incubated with ACR and NaNO2 solutions in the absence and presence of QUE in two different concentrations (3 mM and 500 µM), and changes in albumin alpha-helical structure were determined by CD. BSA secondary structure was vulnerable to alterations upon treatment with acrylamide and NaNO2, as well as quercetin. QUE, depending on concentration and incubation time, caused a decrease of around 13-19% in the alpha-helix content of BSA molecules, but also prevented the changes in the protein alpha-helical structure initiated by ACR and NaNO2. The most spectacular inhibition was revealed for QUE in lower concentrations after 24h of incubation with NaNO2. Although QUE reveals protective effect towards albumin modifications, it is difficult to unambiguously define whether this effect is advantageous, because quercetin itself causes alterations in BSA structure.

2

In vivo and ex vivo impact of nutritional xenobiotics – acrylamide and sodium nitrates – on plasma antioxidant properties

100%

Rorbach-Dolata A., Żurawska-Płaksej E., Marchewka Z., Piwowar A.

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issue 73

154-162

EN

INTRODUCTION: The thiol (SH) groups present in human blood plasma play an important role in the oxidative/antioxidative homeostasis of the organism. They are susceptible to the adverse actions of different exo- and endogenous factors. Chronic exposure to different xenobiotics, e.g. nitrogen-containing compounds commonly occurring in food, is especially important. The aim of this study was to investigate the effect of acrylamide (ACR) and sodium nitrates (SN) – (V) and (III) – on the plasma antioxidant properties, as reflected by changes in the SH group levels. MATERIAL AND METHODS: The concentration of SH groups was measured by Ellman’s method in blood plasma derived from 62 young people (in vivo model; time t0), and after 1 hour of blood plasma incubation with appropriate ACR and SN (III) concentrations (ex vivo model; time t1). The concentrations used corresponded with their daily intake (DIA – daily intake of acrylamide, and DIN – daily intake of sodium nitrates (V) and (III), respectively), estimated on the basis of a nutritional questionnaire. RESULTS: In both models, acrylamide and nitrates caused a significant decrease in SH group concentrations, but ACR induced stronger changes. The women consumed a greater amount of these nitrogen-containing compounds compared to the men, probably due to their different dietary habits. CONCLUSIONS: The obtained results indicate that these nitrogen-containing xenobiotics are important agents lowering antioxidative plasma potential, hence their intake should be controlled.

PL

WSTĘP: Grupy tiolowe (SH) obecne w osoczu krwi odgrywają ważną rolę w oksydacyjno-antyoksydacyjnej homeostazie organizmu. Są one podatne na niekorzystne działanie różnych czynników egzo- i endogennych. Szczególnie istotnym problemem jest długotrwałe narażenie na różne ksenobiotyki, np. związki zawierające azot, powszechnie występujące w żywności. Celem naszych badań była ocena wpływu akrylamidu (acrylamide – ACR) i azotanu sodu (sodium nitrate – SN) – (V) i (III) – na właściwości przeciwutleniające osocza poprzez pomiar stężenia grup SH. MATERIAŁ I METODY: Stężenie grup SH w osoczu uzyskanym od 62 młodych osób (model in vivo; czas t 0) oraz w próbkach poddanych godzinnej inkubacji z odpowiednim stężeniem ACR i SN (III) (model ex vivo; czas t1) mierzono metodą Ellmana. Stężenia ACR i SN (III) w modelu ex vivo odpowiadały ich dziennemu spożyciu (odpowiednio DIA – daily intake of acrylamide – i DIN – daily intake of sodium nitrates (V) i (III)), oszacowanemu na podstawie kwestionariusza żywieniowego. WYNIKI: W obu modelach akrylamid i azotany spowodowały znaczny spadek stężenia grup SH, ale ACR spowodował silniejsze zmiany. Kobiety spożywały większą ilość związków zawierających azot w porównaniu z mężczyznami, prawdopodobnie z powodu odmiennych nawyków żywieniowych. WNIOSKI: Uzyskane wyniki wskazują, że ksenobiotyki zawierające azot są ważnymi czynnikami obniżającymi potencjał antyoksydacyjny osocza, a ich spożycie powinno być kontrolowane.

3

INSIGHTS INTO MYCOBACTERIAL ACTIVITY AND CYTOTOXICITY OF SUBSTITUED ISOXAZOLE-4-CARBOHYDRAZIDE DERIVATIVES.

76%

Płoszaj P., Junka A., Szponar B., Mączyński M., Ryng S., Bartoszewicz M., Piwowar A.

Acta Poloniae Pharmaceutica - Drug Research

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2018

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vol. 75

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issue 3

EN

The purpose of this study was to evaluate the antimycobacterial activity of novel derivatives of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide 1, isoniazid (INH) structural analogue. A set of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide 1 derivatives 2a-j have been obtained by condensation reactions with aldehydes and further transformed by cyclization with corresponding orthoesters to 5-amino-3-methylisoxazole[5,4-d]pyrimidin-4-one derivatives 3a-j and 4a-j. From the structural and functional point of view, all these products proved to be biologically important and could be used as substrates for further synthesis. 21 out of 31 structures were newly developed. Described compounds were screened against Mycobacterium fortuitum in MABA test. The most active compound 2e, 2g revealed minimum inhibitory concentration at 16 μg/ml. In addition, these compounds revealed low cytotoxicity against lung (A549) and fibroblasts (L929) cell lines. The results demonstrated the potential and importance of further development of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide derivatives as a new class of antimycobacterial compounds.

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2 Acta Poloniae Pharmaceutica - Drug Research

1 Annales Academiae Medicae Silesiensis

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2 Żurawska-Płaksej E.

1 Bartoszewicz M.

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1 Marchewka Z.

1 Mączyński M.

1 Płoszaj P.

1 Ryng S.

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Quercetin influences BSA alpha-helical structures of native, ACR- and NaNO2-modified BSAs

In vivo and ex vivo impact of nutritional xenobiotics – acrylamide and sodium nitrates – on plasma antioxidant properties

INSIGHTS INTO MYCOBACTERIAL ACTIVITY AND CYTOTOXICITY OF SUBSTITUED ISOXAZOLE-4-CARBOHYDRAZIDE DERIVATIVES.