P82: Garlic-derived allyl mercaptan, but not diallyl disulfide, inhibits H2S induced no release from S-nitrosoglutathione

Abstract

Medicinal properties of garlic (Allium sativum L.) have been attributed to organosulfur compounds, including diallyl disulfide (DADS) and allyl mercaptan (AM). The potency of DADS and AM to release NO from S-nitrosoglutathione (GSNO, 0.1–0.2 mM), in the absence and presence of H2S donor Na2S (0.1–0.2 mM), was measured as NO oxidation product nitrite ( NO 2 - ) by the Griess reagent and as GSNO decomposition-NO release by UV–vis spectroscopy. AM and DADS (⩽0.8 mM) alone did not release NO from GSNO, whereas DADS (but not AM) released NO in the presence of cysteine and glutathione. But the presence of cystine, N-acetyl-cysteine, oxidized glutathione and methionine had no effect. H2S (0.1–0.2 mM) induced NO release from GSNO (0.1–0.2 mM). AM (0.1–1.2 mM), but not DADS, inhibited the NO release. AM also inhibited products of H2S-GSNO interaction, polysulfides and SSNO−, in a concentration dependent manner. The results suggest a role of DADS and AM in sulfide and nitroso signaling pathways and contribute to the understanding of the beneficial cardiovascular effects of garlic. This work was supported by VEGA 2/0050/13.