P102 Searching for natural products with H2S-releasing properties

Abstract

Hydrogen sulfide (H2S), is signaling molecule that is important for homeostasis and participates in disease generation and progression. In the cardiovascular system H2S promotes angiogenesis, vasodilation and cardioprotection. To deliver H2S inorganic salts (NaSH and Na2S) that generate H2S in burst-like fashion are commonly used. If H2S were to be therapeutically used, compounds that liberate H2S at low levels in a continuous fashion would have to be developed. To date, several H2S compounds of natural origin have been described including diallyltrisulfide, diallyldisulfide, allyl isothiocyanate, E-ajoene, sulforaphane, erucin and iberin. In the present study, we tested a number of extracts from plants known to have a high content of sulphur carrying secondary metabolites as a first step towards identifying novel H2S donors. Extracts from Aubrieta deltoidea (Brassicaceae), Brassica oleracea var. botrytis (Brassicaceae) and Brassica oleracea var. italica (Broccoli, Brassicaceae) were utilized. Plant materials were lyophilized, grinded and extracted using an ASE procedure. The ability of extracts to release H2S was evaluated by the methylene blue method and by the ability of the extracts to raise cGMP. Interestingly, 7 of the fractions tested release H2S as judged both by an increase in cGMP content of reporter cells and by the increase in color development in the methylene blue assay. Further fractionation and purification of the active ingredients in these extracts is underway. We conclude that plants from the Brassicaceae species contain useful H2S-producing natural products that once purified might serve as hypotensive, cardioprotective and angiogenesis-enhancing pharmacological agents.