GPX4 and periodontitis: The results showed that scl7a11 and gpx4 expression decreased and the level of acsl4 and tfr1 were increased in periodontitis group; however, the expression of slc7a11 and gpx4 were increased in the curcumin groups and curcumin can decrease the expression of acsl4 and tfr1 (Figure 5C–F).