Discovery of novel β-elemene hybrids with hydrogen sulfide-releasing moiety possessing cardiovascular protective activity for the treatment of atherosclerosis

Abstract

Herein, a series of novel β-elemene hybrids with different types of hydrogen sulfide (H₂S) donors was designed and synthesized for the first time. In addition, all compounds were tested for H₂S release in phosphate buffer solution assay, among which the derivatives with 5-p-hydroxyphenyl-3H-1,2-dithiole-3-thione (ADT-OH) as the H₂S donor released the best level. The results of the isolated vasodilation assay revealed that all the compounds exhibited a degree of vasodilatory effect, and the representative compound “β-elemene-H₂S gas donor” hybrid L13-2h produced more than 50% vasodilatory activity at a concentration of 20 μM. Furthermore, L13-2h possessed good concentration dependence and significantly better vasodilatory activity than the lead compound L13. In the RAW 264.7 cellular lipid inhibition against oxidized low-density lipoprotein (ox-LDL) stimulation assay, eight compounds, including L13-2g and L13-2h, produced significant cellular lipid-lowering activity. The results of the further antioxidant activity study showed that the representative compounds L13-2g and L13-2h improved H₂O₂-induced oxidative damage in HUVEC cells and compound L13-2h exhibited excellent antioxidant damage protection activity compared to the positive control. Moreover, none of the target compounds appeared to be significantly cytotoxic at the tested concentrations. These results suggest that the hybridization of hydrogen sulfide donors with β-elemene provides a promising approach for the discovery of novel anti-atherosclerotic drugs from natural products.