Historic medicinal practice has defined Cat's Claw, also known as Una de Gato or Uncaria tomentosa, as an effective treatment for several health disorders including chronic inflammation, gastrointestinal dysfunction such as ulcers, tumors and infections. The efficacy of Cat's Claw was originally believed, as early as the 1960s, to be due to the presence of oxindole alkaloids. However, more recently water-soluble Cat's Claw extracts were shown not to contain significant amounts of alkaloids (<0.05%), and yet still were shown to be very efficacious. Here we characterize the active ingredients of a water-soluble Cat's Claw extract called C-Med-100 as inhibiting cell growth without cell death thus providing enhanced opportunities for DNA repair, and the consequences thereof, such as immune stimulation, anti-inflammation and cancer prevention. The active ingredients were chemically defined as quinic acid esters and could also be shown to be bioactive in vivo as quinic acid.