Tetramethylpyrazine Improves the Survival of Saccharomyces cerevisiae by Enhancing Antioxidant Activity

Saccharomyces cerevisiae is an important food microorganism. Previously, we demonstrated that water extract from Ligusticum chuanxiong can delay aging and enhance the fermentation efficiency of S. cerevisiae. Tetramethylpyrazine (TMP), an active alkaloid component of L. chuanxiong, remains to be characterized for its effects on S. cerevisiae. In this study, the effects of TMP on S. cerevisiae were evaluated on the basis of cell apoptosis, reactive oxygen species (ROS) levels, antioxidant enzyme activities, and gene expression levels. Flow cytometry and spotting test results showed that TMP significantly reduced the S. cerevisiae mortality under normal growth conditions. Furthermore, TMP significantly increased activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), and elevated the GSH/GSSG ratio, reflecting an improved intracellular redox state. Further, TMP reduced the levels of intracellular ROS, superoxide anion, and malondialdehyde (MDA) in yeast, revealing decreased oxidative stress. As expected, ethanol stress substantially decreased the activities of SOD, CAT, and GR, while increasing ROS, superoxide anion, and MDA levels in S. cerevisiae. Notably, CAT activity was further reduced by TMP under ethanol stress, suggesting a differential regulatory mechanism. TMP treatment significantly mitigated these oxidative alterations, as evidenced by the dose-dependent elevation of the GSH/GSSG ratio alongside enhanced SOD and GR activities, leading to reduced cell mortality and improved antioxidant capacity. Overall, TMP not only mitigates basal oxidative damage under normal physiological conditions but also protects yeast against ethanol-induced oxidative stress, primarily through the enhancement of antioxidant activity.