Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS) or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H₂S) is now recognized as the third “gasotransmitters” and proved to exert a wide range of physiological and cytoprotective functions in the biological systems. Among these functions, the role of H₂S in oxidative stress has been one of the main focuses over years. However, the underlying mechanisms for the antioxidant effect of H₂S are still poorly comprehended. This review presents an overview of the current understanding of H₂S specially focusing on the new understanding and mechanisms of the antioxidant effects of H₂S based on recent reports. Both inhibition of ROS generation and stimulation of antioxidants are discussed. H₂S‐induced S‐sulfhydration of key proteins (e.g., p66Shc and Keap1) is also one of the focuses of this review.

In this study, we investigated the anticancer effects of FS-7, a flavonoid salicylate derivative, in human gastric carcinoma MGC-803 cell line and studied its preliminary anticancer effects. FS-7 displayed greater in vitro cytotoxicity against MGC-803 cell line compared with 5-Fu and had a certain extent of selectivity to cancer cells. The flow cytometry analysis revealed that FS-7 induced apoptosis MGC-803 cells and mainly caused cells arrest in the G2/M phase in a concentration-dependent manner. Additionally, FS-7 inhibited the colony formation and cell migration in a concentration-dependent manner. Notably, FS-7 noticeably down-regulated glycolysis-related protein HIF-1α, HK-II and PFKP expression in a concentration-dependent manner, possibly causing glycolysis inhibition. Importantly, compared with 5-Fu, FS-7 showed better anticancer activity in the MGC-803 xenograft murine tumor models. Collectively, the present study provided a promising anticancer drug candidate for gastric cancer therapy.