Although the organosulfur compounds from garlic have shown diverse pharmacological activities, the prototype drug was almost undetectable in vivo. As known, methylallyl sulfone (AMSO2) is the main metabolite of some active organosulfur compounds derived from garlic. The purpose of this article was to study the protective effect of AMSO2 on cigarette smoke extract (CSE) induced cell apoptosis in lungs in vivo and in vitro. The male rats were injected intraperitoneally with 900 mu L of 100% CSE 3 times for three successive weeks. The rats from treatment groups were injected intraperitoneally with AMSO2 (50 mg/kg/day or 100 mg/kg/day) or DEX (1 mg/kg/day) for 21 days. We observed that pretreatment of AMSO2 effectively reversed apoptosis and oxidative stress in rats induced by CSE. Moreover, CSE-induced apoptosis in the HFL-1 cells was significantly suppressed by pretreated AMSO2 (400 mu M) and DEX (0.1 mg/mL). Mechanistic studies suggested that this activity may arise from its effects on the regulation of p38 MAPK, Nrf-2 and Bcl-2/Bax signaling pathways. Overall, the metabolite of active organosulfur compounds AMSO2 might be a potential candidate for the treatment of CSE-induced apoptosis in rats. (C) 2018 Elsevier Inc. All rights reserved.