Identification of potential activator and inhibitor of autophagy. (a) Distribution of compounds. Fluorescence intensities are expressed relative to full medium (FM) conditions (fluorescence intensity under FM = 1). Each plate contained nutrient deprivation (ND) medium (relative fluorescence intensity = 0.55) and rapamycin (relative fluorescence intensity = 0.71) as positive and bafilomycin A1 (Baf) (relative fluorescence = 1.37) as negative controls. Compounds were considered as hits if fluorescence intensities were higher/lower than mean ± σ. (b) Primary hits identified by flow cytometry based autophagy screen. Autophagy inducers/inhibitors were grouped into respective classes. Color labeling (green/red) represents previously reported cardioprotective/cardiotoxic effects. Previously reported anti-cancer properties are indicated by filled squares. Respective PubMed database identification numbers (PMIDs) can be found in Additional file 9.