AbstractA growing body of evidence suggests that anthocyanins and anthocyanidins may possess analgesic properties in addition to neuroprotective and anti-inflammatory activities. These functionalities suggest a role for the cannabinoid receptor (CB) in mediating biological effects. Competitive radioligand binding assays identified cyanidin (Ki= 16.2 μM) and delphinidin (Ki= 21.3 μM) as ligands with moderate affinity to human CB1. For CB2, similar affinities were achieved by cyanidin (Ki= 33.5 μM), delphinidin (Ki= 34.3 μM), and peonidin (Ki= 46.4 μM). Inhibition constants >50 μMwere obtained for pelargonidin, malvidin, cyanidin-3,5-di-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, and cyanidin-3-O-rutinoside for both CB subtypes. [ABSTRACT FROM AUTHOR]