Aged garlic extract and S-allylcysteine prevent apoptotic cell death in a chemical hypoxia model

BACKGROUND: Aged garlic extract (AGE) and its main constituent S-allylcysteine (SAC) are natural antioxidants with protective effects against cerebral ischemia or cancer, events that involve hypoxia stress. Cobalt chloride (CoCl(2)) has been used to mimic hypoxic conditions through the stabilization of the α subunit of hypoxia inducible factor (HIF-1α) and up-regulation of HIF-1α-dependent genes as well as activation of hypoxic conditions such as reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and apoptosis. The present study was designed to assess the effect of AGE and SAC on the CoCl(2)-chemical hypoxia model in PC12 cells. RESULTS: We found that CoCl(2) induced the stabilization of HIF-1α and its nuclear localization. CoCl(2) produced ROS and apoptotic cell death that depended on hypoxia extent. The treatment with AGE and SAC decreased ROS and protected against CoCl(2)-induced apoptotic cell death which depended on the CoCl(2) concentration and incubation time. SAC or AGE decreased the number of cells in the early and late stages of apoptosis. Interestingly, this protective effect was associated with attenuation in HIF-1α stabilization, activity not previously reported for AGE and SAC. CONCLUSIONS: Obtained results show that AGE and SAC decreased apoptotic CoCl(2)-induced cell death. This protection occurs by affecting the activity of HIF-1α and supports the use of these natural compounds as a therapeutic alternative for hypoxic conditions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40659-016-0067-6) contains supplementary material, which is available to authorized users.