*4.1. Cell Culture and Treatment*

Human cardiomyocyte cell line AC16 were purchased from Merch Company (SCC 109). Rat cardiomyocyte cell line H9c2 (CRL-1466), human breast cancer cell line MCF-7 (HTB-22), and human cervical cancer cell line HeLa (CCL-2) were purchased from America Tissue Type Collection (ATCC, Bethesda, Rockville, MD, USA). Cells were routinely cultured in Dulbecco's modified Eagle's medium (DMEM) containing 25 mmol/L glucose and L-glutamine (Sigma, St. Louis, MO, USA) and 10% fetal bovine serum (FBS) (HyClone, Logan, UT, USA). Cells were maintained at 37 ◦C and 5% CO2. For 10 mM galactose DMEM, D-galactose (Sigma, St. Louis, MO, USA) was added to the media. Spinochrome D (SpD, purity 98%) was isolated from the sea urchin *Scaphechinus mirabilis*, as described in [44], as the red powder with m.p. >320 ◦C and spectral characteristics, as in [45].
