Fig. 3

Circadian clock regulation of curcumin efficacy. a-c: Mitotic events in C6 cultures showed circadian rhythms in 0 and 10 μM but not 5 μM CUR. d-f: Cell death rates (apoptotic events/hr) displayed circadian rhythms in 0 and 5 but not 10 μM CUR (blue circles: events, red line: after adjacent averaging). g-i: Apoptotic and mitotic rates were inversely correlated as shown by linear regressions. j, k: The phase of cell death events displayed significant clustering (p < 0.001) in 5 μM CUR on days 2 and 3 (left and right, Z = 14.62 and 7.399 by Rayleigh Test, respectively). Long arrow indicates phase of mean vector. Short arrow (green) indicates peak of mPER2::LUC rhythm from Fig. 1. The curcumin treatment began at 12:00 AM (0:00) on Day 1. Each dot indicates 2 events