Figure 1.
Percentage change in body mass of female BALB/c mice at the end of the study relative to baseline mass prior to tumor cell inoculation (1 × 106 cells). Mice were kept under short photoperiod (8 L:16D, lights were on from 8:00 to 16:00 hours) at 4 different spectral compositions with or without melatonin (MLT) supplement for 28 days. Melatonin was nocturnally administered in the drinking water (10 mg/L). Mice in all spectral groups were exposed to 1 × 30-minute/night artificial light at night at 00:00 using the same light source and spectral composition as during the day. Results are presented as mean ± standard error (SE) of n = 6-10. Different letters represent statistically significant difference among groups (Tukey P = .01).