The effect of NaCl on the level of reduced sulfur compounds in rat liver. Implications for blood pressure increase.

Background: It is commonly known that excessive salt intake is a risk factor of hypertension. Currently, there is an increasing interest in reduced reactive sulfur species (RSS), mainly H2S and sulfane sulfur (SS) as new gasotransmitters showing vasorelaxant properties. The aim of the present study was to determine the effect of repeated administration of low sodium chloride dose included in physiological saline on blood pressure, on the level of RSS and activity of enzymes involved in their biosynthesis in the rat.

Lipoic Acid as a Possible Pharmacological Source of Hydrogen Sulfide/Sulfane Sulfur.

The aim of the present study was to verify whether lipoic acid (LA) itself is a source of H₂S and sulfane sulfur. It was investigated in vitro non-enzymatically and enzymatically (in the presence of rat tissue homogenate). The results indicate that both H₂S and sulfane sulfur are formed from LA non-enzymatically in the presence of environmental light.

The Effects of Different Garlic-Derived Allyl Sulfides on Anaerobic Sulfur Metabolism in the Mouse Kidney.

Diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS) are major oil-soluble organosulfur compounds of garlic responsible for most of its pharmacological effects. The present study investigated the influence of repeated administration of DAS, DADS and DATS on the total level of sulfane sulfur, bound sulfur (S-sulfhydration) and hydrogen sulfide (H₂S) and on the activity of enzymes, which catalyze sulfane sulfur formation and transfer from a donor to an acceptor in the normal mouse kidney, i.e.

INACTIVATION OF ALDEHYDE DEHYDROGENASE BY NITROGLYCERIN IN THE PRESENCE AND ABSENCE OF LIPOIC ACID AND DIHYDROLIPOIC ACID. IMPLICATIONS FOR THE PROBLEM OF DIFFERENTIAL EFFECTS OF LIPOIC ACID IN VITRO AND IN VIVO.

Lipoic acid (LA-(SS), LA) and its reduced form - dihydrolipoic acid DHLA-(SH)2, DHLA) are synthesized mainly in the mammalian liver. In this study, we investigated in viti the inactivation of yeast aldehyde dehydrogenase (ALDH) by nitroglycerin (GTN) in the presence and absence of LA and DHLA. In vivo studies were performed to answer the question whether LA administered jointly with GTN for 8 days will affect the ALDH activity in the rat liver.

The effect of lipoate on anaerobic cysteine metabolism in erythrocytes of patients treated with peritoneal dialysis.

Background: The studies aimed to evaluate the changes in cysteine sulfur metabolism in erythrocytes of end-stage renal failure (ESRF) patients treated with continuous ambulatory peritoneal dialysis (CAPD) caused by a one-month lipoate (LA) supplementation at a daily dose of 600 mg.

Methods: The level of sulfane sulfur and activity of sulfurtransferases were determined in erythrocytes of CAPD patients and in the control group.

Results: The sulfane sulfur level in erythrocytes of CAPD patients did not differ compared with healthy volunteers but LA supplementation increased the reactive sulfur concentration.

In vivo anti-inflammatory activity of lipoic acid derivatives in mice.

Background: In mammals lipoic acid (LA) and its reduced form dihydrolipoic acid (DHLA) function as cofactors for multienzymatic complexes catalyzing the decarboxylation of α-ketoacids. Moreover, LA is used as a drug in a variety of diseases including inflammatory diseases. The aim of the study was to examine anti-inflammatory properties of LA metabolites.

Effects of acetylsalicylic acid on the levels of sulfane sulfur and non-protein sulfhydryl groups in mouse tissues.

Background: The study is focused on searching for the link between acetylsalicylic acid (ASA) and sulfur metabolism. The present work aimed to investigate the effect of ASA on the level of the sulfane sulfur and non-protein thiol compounds (NPSH) in the liver and kidneys of mice.

Methods: The study was conducted on female albino Swiss mice weighing approximately 20 g.

The effects of garlic-derived sulfur compounds on cell proliferation, caspase 3 activity, thiol levels and anaerobic sulfur metabolism in human hepatoblastoma HepG2 cells.

The aim of the present studies was to determine whether the mechanism of biological action of garlic-derived sulfur compounds in human hepatoma (HepG2) cells can be dependent on the presence of labile sulfane sulfur in their molecules. We investigated the effect of allyl sulfides from garlic: monosulfide, disulfide and trisulfide on cell proliferation and viability, caspase 3 activity and hydrogen peroxide (H(2)O(2)) production in HepG2 cells. In parallel, we also examined the influence of the previously mentioned compounds on the levels of thiols, glutathione, cysteine and cysteinyl-glycine, and on the level of sulfane sulfur and the activity of its metabolic enzymes: rhodanese, 3-mercaptopyruvate sulfurtransferase and cystathionase.

The effect of nitroglycerin tolerance on oxidative stress and anaerobic sulfur metabolism in rat tissues.

The present results indicated that tolerance to nitroglycerin (glycerin trinitrate, GTN) increased the hepatic and renal level of reactive oxygen species, malondialdehyde, and glutathione peroxidase (PO(x)) and decreased superoxide dismutase activity, whereas non-protein thiols remained unchanged in both organs. In the liver (but not in the kidney) glutathione S-transferase (GST), catalase and rhodanese activities decreased and the sulfane sulfur level also dropped. Unlike in the liver, gamma-glutamyl transpeptidase (gammaGT) activity in the kidney declined.

[Glutatione transferases--structure and functions. beta-lyase-dependent bioactivation of cysteine S-conjugates].

Glutathione transferases (GSTs) catalyze nucleophilic attack of glutathione on electrophilic center of the second substrate, hydrophobic in character. It leads to the formation of glutathione S-conjugates (thioethers), which are subsequently eliminated from the organism as mercapturic acids. However, in some reactions, glutathione can also fulfills the role of a cofactor, facilitating transformation of a hydrophobic substrate molecule, and released after the structure has been changed.

The role of lipoic acid in prevention of nitroglycerin tolerance.

Besides other organic nitrates, nitroglycerin (glyceryl trinitrate; GTN) has been used to treat acute heart failure particularly due to ischemic heart disease. However, one of serious clinical problems of the GTN therapy, particularly a long-standing medication, is hemodynamic tolerance to GTN, manifested by the decreased therapeutic efficacy of the drug. The most recent studies have suggested that mitochondrial lipoate/dihydrolipoate system-dependent aldehyde dehydrogenase-2 plays a key role in nitric oxide release from GTN.

Biological actions of lipoic acid associated with sulfane sulfur metabolism.

This work aimed to investigate the effect of lipoic acid (LA) on sulfane sulfur (S(*)) level and rhodanese activity in rat tissues. In vitro studies conduced so far have indicated that dihydrolipoic acid serves as an S(*) acceptor in the rhodanese-catalyzed S(*) transfer. This study revealed a significant increase in S(*) level and rhodanese activity in the heart, liver and kidney homogenates from rats that had previously been treated intraperitoneally with LA.