The use of complementary and alternative medicine (CAM) has increased in the United States and more patients are seeking CAM
therapies for control of pain. The present investigation tested the efficacy of orally administered anthocyanins extracted from tart cherries on
inflammation-induced pain behavior in rats. Paw withdrawal latency to radiant heat and paw withdrawal threshold to von Frey probes were
measured. The first set of experiments examined the effects of tart cherry anthocyanins (400 mg/kg) on the nociceptive behaviors and edema
associated with inflammation induced by intraplantar injection of 1% carrageenan. These studies also included tests of motor coordination.
The second set of experiments determined if tart cherry anthocyanins (15, 85, and 400 mg/kg) dose-dependently affected the inflammation
induced by intraplantar injection of 25% complete Freund’s adjuvant. We found that tart cherry extracts reduce inflammation-induced
thermal hyperalgesia, mechanical hyperalgesia and paw edema. The suppression of thermal hyperalgesia was dose-dependent and the
efficacy of highest dose (400 mg/kg) was similar to indomethacin (5 mg/kg). The highest dose anthocyanin (400 mg/kg) had no effects on
motor function. These data suggest that tart cherry anthocyanins may have a beneficial role in the treatment of inflammatory pain. The
antihyperalgesic effects may be related to the anti-inflammatory and antioxidant properties of anthocyanins. A better understanding of the
modulatory role of dietary constituents and phytonutrients on pain will offer further therapeutic options for treating patients with persistent
and chronic pain conditions.