Antiviral activity of proanthocyanidin against feline calicivirus used as a surrogate for noroviruses, and coxsackievirus used as a representative enteric virus.

Proanthocyanidin, which consists of (+) catechin, (-) epicatechin and their gallates (15%), (-) epicatechin gallate-dimers, -trimers, and -tetramers (80%), and (-) epicatechin gallate-pentamers, -hexamers, and -heptamers (5%), was evaluated for its antiviral activity against feline calicivirus F9 strain (FCV/F9), which is thought to be a surrogate for noroviruses, and coxsackievirus A7 strain (Cox.A7), which was selected as a representative enteric virus. To achieve a viral inactivation rate of 99% or greater after contact for 10 sec., at least 1 mg/ml and 10 mg/ml of proanthocyanidin were required against FCV/F9 and Cox.A7, respectively. Although the antiviral mechanism of proanthocyanidin is not clear at present, proanthocyanidin may be an effective disinfectant against enteroviruses such as noroviruses.