Location: Produce Safety and Microbiology ResearchTitle: Inhibition of Tulane Virus replication via exposure to lowbush blueberry (Vaccinium angustifolium) fractional components
|Bridges, David - University Of Maine|
|Beard, Anna - University Of Maine|
|Lacombe, Alison - National College Of Natural Medicine|
|Valentine, Don - Western Washington University|
|Tadepalli, Shravani - University Of Maine|
Submitted to: Journal of Berry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2017
Publication Date: 7/26/2017
Citation: Bridges, D., Beard, A., Lacombe, A., Valentine, D.C., Tadepalli, S., Wu, V.C. 2017. Inhibition of Tulane Virus replication via exposure to lowbush blueberry (Vaccinium angustifolium) fractional components. Journal of Berry Research. 7(4):281-289. doi:10.3233/JBR-170164.
Interpretive Summary: Human norovirus is a highly infectious as well as environmental stable foodborne pathogen. Research has shown that conventional controls are ineffective in reducing norovirus and other viral pathogens down to noninfectious levels. Therefore, research into alternative antiviral treatments are needed. Phytochemicals derived from lowbush blueberries (Vaccinium angustifolium) have shown strong antibacterial properties in previous studies. However, comparatively little research has been done investigating potential antiviral aspects. The aim of the current study is to look at the phenotypic responses of Tulane Virus (TV), a commonly used norovirus surrogate, when exposed to five fractional components of lowbush blueberry extract. TV reproduction was found to be reduced, compared to a distilled water control, after being exposed to dilutions of each of the five phenolic extracts. Most noticeably, exposure to the total blueberry extract fraction reduced TV reproduction down to undetectable levels without harming the host cell. This indicates great potential use for lowbush blueberry phytochemicals as antiviral agents in the future.
Technical Abstract: Tulane Virus (TV) is a common viral surrogate for human norovirus in lab studies. In the present study, the phenotypic response of TV when exposed to fractional components extracted from lowbush blueberries was investigated. Lowbush blueberry extract (F1) was separated using a C-18 Sep-Pak cartridge into monomeric phenolics (F2) and anthocyanins plus proanthocyanidins (F3). Fraction 3 was further separated into anthocyanins (F4) and proanthocyanidins (F5) using a LH-20 Sephadex column. LLC-MK2 cells, used to grow TV, was exposed to solutions containing both the blueberry factions and TV inoculum. After a 1 h period to allow virus interaction with the blueberry fractions and host cells, the reduction in virus replication was quantified using plaque assays. TV had the strongest response to total blueberry extract (F1), resulting in the growth reduction to undetectable levels (> 4.95 log PFU/ml) followed by anthocyanins plus proanthocyanidins (F3; 4.14 ± 0.83 log PFU/ml), monomeric phenolics (F2; 2.90 ± 0.09 log PFU/ml), anthocyanins (F4; 2.27 ± 0.29 log PFU/ml), and proanthocyanidins (F5; 1.73 ± 0.25 log PFU/ml) at a 1:2 dilution of each fraction. The significant reduction of TV indicates great promise for future research in using blueberries as antiviral agents against human norovirus and other viruses.