Author(s)

Uchenna Iloghalu^1,2, Bryce Holmes¹, Janak Khatiwada^1,2, Leonard L. Williams^1,2*

¹North Carolina A&T State University, Greensboro, USA.
²Center for Excellence in Post-Harvest Technologies, Kannapolis, USA.

Noroviruses are the most common cause of acute gastroenteritis. Annually, 21 million Americans are infected with norovirus. Recent advances in molecular diagnostics have helped to establish norovirus as the most common cause of outbreaks of acute gastroenteritis across all ages. However, there is no effective or efficient treatment/control against norovirus infection. Conventional intervention techniques used to inactivate norovirus have shown lack of efficacy against human norovirus. Currently, effective treatment or control measures against human norovirus have not been identified. In this study, murine norovirus acts as a model to human norovirus to evaluate the inhibitory effects of crude extracts of Zanthoxylum armatum and Hibiscus sabdariffa. The study also separated, identified and quantified the selected compounds using the ultra-liquid chromatography (UPLC). To study the antiviral activities of crude extracts and its fractionated portions of Z. armatum and H. sabdariffa against norovirus surrogate, RAW 264.7 cells were infected with Murine norovirus surrogate virus of human norovirus and incubated at 37˚C. Phytochemicals were extracted from the seeds and calyces of the plants using methanolic extraction. Fractionated portions of the crude extracts were subsequently used in both chromatographic and microbiological studies. Our data indicated that there was reduction of viruses, when treated with the 60% aqueous methanol extracts. Amongst the four selected phenolic compounds (myricetin, quercetin, kaempferol and luteolin), quercetin showed the most significant logarithmic viral reductions. These compounds were identified, purified and quantified using UPLC. Extracts of Zanthoxylum armatum and Hibiscus sabdariffa showed antiviral effects. Phenolic compounds are virucidal. Extracts of Hibiscus sabdariffa also exhibits anti-norovirus activities. The results are anticipated to control/prevent the human norovirus infections.

Plant Extracts, Fractionation, Noroviruses, Plaque Assay

Iloghalu, U. , Holmes, B. , Khatiwada, J. and Williams, L. (2019) Selected Plant Extracts Show Antiviral Effects against Murine Norovirus Surrogate. Advances in Microbiology, 9, 372-384. doi: 10.4236/aim.2019.94022.