title: Blueberry proanthocyanidins against human norovirus surrogates in model foods and under simulated gastric conditions.
abstract: Blueberry proanthocyanidins (B-PAC) are known to decrease titers of human norovirus surrogates in vitro. The application of B-PAC as therapeutic or preventive options against foodborne viral illness needs to be determined using model foods and simulated gastric conditions in vitro. The objective of this study was to evaluate the antiviral effect of B-PAC in model foods (apple juice (AJ) and 2% reduced fat milk) and simulated gastrointestinal fluids against cultivable human norovirus surrogates (feline calicivirus; FCV-F9 and murine norovirus; MNV-1) over 24 h at 37 °C. Equal amounts of each virus (5 log PFU/ml) was mixed with B-PAC (1, 2 and 5 mg/ml) prepared either in AJ, or 2% milk, or simulated gastric fluids and incubated over 24 h at 37 °C. Controls included phosphate buffered saline, malic acid (pH 7.2), AJ, 2% milk or simulated gastric and intestinal fluids incubated with virus over 24 h at 37 °C. The tested viruses were reduced to undetectable levels within 15 min with B-PAC (1, 2 and 5 mg/ml) in AJ (pH 3.6). However, antiviral activity of B-PAC was reduced in milk. FCV-F9 was reduced by 0.4 and 1.09 log PFU/ml with 2 and 5 mg/ml B-PAC in milk, respectively and MNV-1 titers were reduced by 0.81 log PFU/ml with 5 mg/ml B-PAC in milk after 24 h. B-PAC at 5 mg/ml in simulated intestinal fluid reduced titers of the tested viruses to undetectable levels within 30 min. Overall, these results show the potential of B-PAC as preventive and therapeutic options for foodborne viral illnesses.
authors.affiliation: The University of Tennessee-Knoxville, Department of Food Science and Technology, 2600 River Drive, Knoxville, TN 37966, USA.
authors.forename: Snehal
authors.initials: S
authors.lastname: Joshi
authors.affiliation: Marucci Center for Blueberry and Cranberry Research, Rutgers University, Chatsworth, NJ, USA.
authors.forename: Amy B
authors.initials: AB
authors.lastname: Howell
authors.affiliation: The University of Tennessee-Knoxville, Department of Food Science and Technology, 2600 River Drive, Knoxville, TN 37966, USA. Electronic address: ddsouza@utk.edu.
authors.forename: Doris H
authors.initials: DH
authors.lastname: D'Souza
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D029798:Blueberry Plants / Q000737:chemistry*; D017927:Calicivirus, Feline / Q000187:drug effects / Q000254:growth & development*; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000517:prevention & control; D000067030:Fruit and Vegetable Juices / Q000032:analysis / Q000821:virology; D005744:Gastric Acid / Q000737:chemistry; D041981:Gastrointestinal Tract / Q000821:virology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008892:Milk / Q000821:virology; D029322:Norovirus / Q000145:classification / Q000187:drug effects / Q000254:growth & development*; D044945:Proanthocyanidins / Q000494:pharmacology*; D010948:Viral Plaque Assay; D038301:Virus Inactivation; D014780:Viruses / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D044945:Proanthocyanidins
keywords: Blueberry polyphenols; Feline calicivirus; Model foods; Murine norovirus; Simulated gastric conditions