The abietane diterpene taxodione contributes to the antioxidant activity of rosemary by-product in muscle tissue

Research on rosemary antioxidant activity and its potential use in human health and food applications is focused on rosemary leaves and two main bioactive compounds carnosic acid and carnosol. However, many other, not-yet identified molecules could be present, especially in rosemary by-products. In this study, we first showed that rosemary stem extract was the most efficient in protecting human skeletal muscle cells against oxidation. Then, using bioassay-guided fractionation, we identified taxodione, an abietane diterpene, as the main bioactive molecule in the rosemary stem extract. We demonstrated that taxodione protects skeletal muscle cells from hydrogen peroxide-induced cytotoxic damage (by monitoring ROS production, H2AX phosphorylation and CHOP gene expression). Moreover, we showed that taxodione reduces lipid and protein oxidation in post-mortem mice and beef muscles during refrigerated storage. In conclusion, our results indicate that taxodione extracted from rosemary stems, a cheap and unused resource of natural antioxidants, limits oxidation in muscle tissue.