[Note: Proanthocyanidins are chains of antioxidant flavonoids derived from plant sources such as cranberries, green tea, pine bark, cinnamon, cocoa, grape skins and seeds, red wine. Enteric viruses attack the lining of organ systems such as the digestive & respiratory tracts and are spread by respiratory secretions, stool and foods they contaminate.]
The effect of cranberry juice (CJ) and cranberry proanthocyanidins (PAC) on the infectivity of human enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), MS2(ssRNA) bacteriophage, and phiX-174(ssDNA) bacteriophage was studied.
Viruses at high (approximately 7 log(10) PFU/ml) or low (approximately 5 log(10) PFU/ml) titers were mixed with equal volumes of cranberry juice, 0.30, 0.60, and 1.20 mg/ml final cranberry proanthocyanidins concentration, or water and incubated for 1 hour at room temperature.
Viral infectivity after treatments was evaluated using standardized plaque assays.
• At low viral titers, FCV-F9 was undetectable after exposure to cranberry juice or the three tested cranberry proanthocyanidins solutions.
• MNV-1 was reduced by 2.06 log(10) PFU/ml with cranberry juice, and 2.63, 2.75, and 2.95 log(10) PFU/ml with 0.15, 0.30, and 0.60 mg/ml cranberry proanthocyanidins, respectively.
• MS2 titers were reduced by 1.14 log(10) PFU/ml with cranberry juice, and 0.55, 0.80, and 0.96 log(10) PFU/ml with 0.15, 0.30, and 0.60 mg/ml cranberry proanthocyanidins, respectively.
• phi-X174 titers were reduced by 1.79 log(10) PFU/ml with cranberry juice, and 1.95, 3.67, and 4.98 log(10) PFU/ml with cranberry proanthocyanidins at 0.15, 0.30, and 0.60 mg/ml, respectively.
Experiments using high titers showed similar trends but with decreased effects.
Cranberry juice and cranberry proanthocyanidins show promise as natural antivirals that could potentially be exploited for foodborne viral illness treatment and prevention.
Source: Food Microbiology, Jun 2010; 27(4):535-40. PMID: 20417404, by Su X, Howell AB, D’Souza DH. Department of Food Science and Technology, University of Tennessee-Knoxville, Knoxville, Tennessee; Marucci Center for Blueberry Cranberry Research, Rutgers University, Chatsworth, New Jersey, USA. [Email: Doris H D’Souza – email@example.com]