Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea

Saliva plays major roles in the human-to-human transmission of SARS-CoV-2. If the virus in saliva in SARS-CoV-2-infected individuals can be rapidly and efficiently inactivated by a beverage, the ingestion of the beverage may attenuate the spread of virus infection within a population. Recently, we r...

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Main Authors: Eriko Ohgitani, Masaharu Shin-Ya, Masaki Ichitani, Makoto Kobayashi, Takanobu Takihara, Masaya Kawamoto, Hitoshi Kinugasa, Osam Mazda
Format: Article
Language:English
Published: MDPI AG 2021-06-01
Series:Pathogens
Subjects:
Online Access:https://www.mdpi.com/2076-0817/10/6/721
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author Eriko Ohgitani
Masaharu Shin-Ya
Masaki Ichitani
Makoto Kobayashi
Takanobu Takihara
Masaya Kawamoto
Hitoshi Kinugasa
Osam Mazda
author_facet Eriko Ohgitani
Masaharu Shin-Ya
Masaki Ichitani
Makoto Kobayashi
Takanobu Takihara
Masaya Kawamoto
Hitoshi Kinugasa
Osam Mazda
author_sort Eriko Ohgitani
collection DOAJ
description Saliva plays major roles in the human-to-human transmission of SARS-CoV-2. If the virus in saliva in SARS-CoV-2-infected individuals can be rapidly and efficiently inactivated by a beverage, the ingestion of the beverage may attenuate the spread of virus infection within a population. Recently, we reported that SARS-CoV-2 was significantly inactivated by treatment with black tea, green tea, roasted green tea and oolong tea, as well as their constituents, (-) epigallocatechin gallate (EGCG), theasinensin A (TSA), and galloylated theaflavins. However, it remains unclear to what extent tea inactivates the virus present in saliva, because saliva contains various proteins, nitrogenous products, electrolytes, and so on, which could influence the antivirus effect of tea. Here, we assessed whether tea inactivated the SARS-CoV-2 which was added in human saliva. A virus was added in healthy human saliva in vitro, and after treatment with black tea or green tea, the infectivity of the virus was evaluated by TCID<sub>50</sub> assays. The virus titer fell below the detectable level or less than 1/100 after treatment with black tea or green tea for 10 s. The black tea-treated virus less remarkably replicated in cells compared with the untreated virus. These findings suggest the possibility that the ingestion of tea may inactivate SARS-CoV-2 in saliva in infected individuals, although clinical studies are required to determine the intensity and duration of the anti-viral effect of tea in saliva in humans.
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spelling doaj.art-cc8cbbbcb9aa49b5840d73360109f3542023-11-21T23:13:51ZengMDPI AGPathogens2076-08172021-06-0110672110.3390/pathogens10060721Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green TeaEriko Ohgitani0Masaharu Shin-Ya1Masaki Ichitani2Makoto Kobayashi3Takanobu Takihara4Masaya Kawamoto5Hitoshi Kinugasa6Osam Mazda7Department of Immunology, Kyoto Prefectural University of Medicine, Kamigyo, Kyoto 602-8566, JapanDepartment of Immunology, Kyoto Prefectural University of Medicine, Kamigyo, Kyoto 602-8566, JapanCentral Research Institute, ITO EN, Ltd., Makinohara, Shizuoka 421-0516, JapanCentral Research Institute, ITO EN, Ltd., Makinohara, Shizuoka 421-0516, JapanCentral Research Institute, ITO EN, Ltd., Makinohara, Shizuoka 421-0516, JapanDepartment of Immunology, Kyoto Prefectural University of Medicine, Kamigyo, Kyoto 602-8566, JapanCentral Research Institute, ITO EN, Ltd., Makinohara, Shizuoka 421-0516, JapanDepartment of Immunology, Kyoto Prefectural University of Medicine, Kamigyo, Kyoto 602-8566, JapanSaliva plays major roles in the human-to-human transmission of SARS-CoV-2. If the virus in saliva in SARS-CoV-2-infected individuals can be rapidly and efficiently inactivated by a beverage, the ingestion of the beverage may attenuate the spread of virus infection within a population. Recently, we reported that SARS-CoV-2 was significantly inactivated by treatment with black tea, green tea, roasted green tea and oolong tea, as well as their constituents, (-) epigallocatechin gallate (EGCG), theasinensin A (TSA), and galloylated theaflavins. However, it remains unclear to what extent tea inactivates the virus present in saliva, because saliva contains various proteins, nitrogenous products, electrolytes, and so on, which could influence the antivirus effect of tea. Here, we assessed whether tea inactivated the SARS-CoV-2 which was added in human saliva. A virus was added in healthy human saliva in vitro, and after treatment with black tea or green tea, the infectivity of the virus was evaluated by TCID<sub>50</sub> assays. The virus titer fell below the detectable level or less than 1/100 after treatment with black tea or green tea for 10 s. The black tea-treated virus less remarkably replicated in cells compared with the untreated virus. These findings suggest the possibility that the ingestion of tea may inactivate SARS-CoV-2 in saliva in infected individuals, although clinical studies are required to determine the intensity and duration of the anti-viral effect of tea in saliva in humans.https://www.mdpi.com/2076-0817/10/6/721novel coronavirusCOVID-19teacatechintheaflavinsaliva
spellingShingle Eriko Ohgitani
Masaharu Shin-Ya
Masaki Ichitani
Makoto Kobayashi
Takanobu Takihara
Masaya Kawamoto
Hitoshi Kinugasa
Osam Mazda
Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea
Pathogens
novel coronavirus
COVID-19
tea
catechin
theaflavin
saliva
title Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea
title_full Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea
title_fullStr Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea
title_full_unstemmed Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea
title_short Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea
title_sort rapid inactivation in vitro of sars cov 2 in saliva by black tea and green tea
topic novel coronavirus
COVID-19
tea
catechin
theaflavin
saliva
url https://www.mdpi.com/2076-0817/10/6/721
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