技術説明

A new development in virus inactivation with a natural ingredient - green tea catechin (EGCg)

Patent application 〈Processing technology to stabilize green tea catechins (EGCg) at high concentrations in aqueous solutions〉 started in August 2021

The outbreak of the novel coronavirus (COVID-19) has completely changed social life.

While the development of vaccines and therapeutic agents is progressing, the outbreak of new mutant virus strains is requiring increasingly strong preventive measures. In such a situation, green tea catechin (Epigallocatechin gallate, EGCg), as a natural ingredient with potential antiviral effects, has been verified and published for its inactivating effects against viruses in Japan and overseas.

However, catechins and EGCg, which have a strong antioxidant effect, are highly susceptible to oxidative deterioration and lack storage stability, which is a major drawback in the development of various products.

To overcome this lack of stability, a formulation that is stabilized at a high concentration in water has been developed, and verification experiments have shown that it is effective in inactivating various viruses that repeatedly mutate, such as influenza and novel coronaviruses, by binding to viral proteins and preventing them from entering cells. It has also been shown in verification experiments that it has an inactivating effect by binding to viral proteins.

- A research team led by Professor Masahiko Kurokawa, Vice President, Dean of the Faculty of Pharmaceutical Sciences, Kyushu University of Health and Welfare, conducted verification experiments on the inactivation effects of various influenza viruses.

- The inactivation of other viruses, such as the novel coronavirus and SARS virus, was verified by a research team led by the National　University.

Effective inactivation of all viruses confirmed

New development in preventive measures

HPG Co., Ltd. (Chuo-ku, Tokyo; Masanori Kanayama, President) has successfully developed a water-soluble formulation technology of highly concentrated catechin EGCg with excellent storage stability and has started to apply for a patent as the world's first processing technology to stabilize the product at a high concentration in aqueous solution.

Currently, this aqueous solution formulation is stabilized at a high concentration of 10,000 ppm, and the concentration can be easily adjusted by dilution.

In addition, since all the components that stabilize the product are food additives approved by the Ministry of Health, Labor and Welfare, there is no need to worry about adverse reactions if they enter the body, and children and the elderly can take the product through oral care without anxiety.

Furthermore, depending on the concentration added, if the concentration shows an inactivation effect, there is almost no damage to the original taste, aroma, or color of existing products due to astringency, bitterness, or discoloration peculiar to catechin EGCg, and the product can be used in a variety of fields.

- Potential of highly concentrated catechin, EGCg pharmaceutical preparations

At present, there are a variety of products on the market to prevent viral infections, but since this technological product is highly effective against bacteria as well as viruses, it can be used as a substitute for alcohol products that can cause rough hands, in the kitchen and food handling fields, and as a preventive measure against not only human but also bird flu and swine flu.

Summary of verification data from the Kurokawa Research Team

Green tea is rich in catechins, and epigallocatechin gallate (EGCg), one of the catechins, is known to have an antiviral effect by inhibiting the adsorption process of the virus to cells during the replication process. In this study, we examined the anti-influenza effect of EGCg and its mechanism of action by performing plaque reduction assay using MDCK (Madin-Darby canine kidney) cells against four kinds of influenza A and B virus strains in vitro. They investigated the anti-influenza effect of EGCg by performing plaque reduction assay using MDCK (Madin-Darby canine kidney) cells. As a result, they confirmed that EGCg inhibited the adsorption or entry process of virus particles into the cells for four kinds of influenza virus strains.

Profile of Masahiko Kurokawa:

Vice President, Dean, Director of Pharmaceutical Sciences, Kyushu University of Health and Welfare

Professor, Department of Biochemistry, Graduate School of Medical and

Pharmaceutical Sciences

Research Description:

We have been conducting research on the development of new antiviral drugs from traditional medicines and supplements, the pathogenesis of viral infections and the analysis of host immune defense mechanisms, as well as basic research on viral vectors for gene therapy. In addition to these studies, we have been conducting research to prove and analyze the exacerbation of infectious diseases caused by exposure to environmental chemicals in the fetal and neonatal period and metabolic syndrome using virus-infected animals as research that can contribute to the maintenance and improvement of QOL. In recent years, we have been conducting research on elucidation of pathological mechanisms of infectious diseases and lifestyle-related diseases, development of novel preventive and therapeutic methods, and risk assessment of environmental chemicals on host immune mechanisms by using knowledge and experimental techniques in biochemistry, molecular and cellular biology, genetic engineering, bacteriology, virology, and immunology. For these research, we have established a collaborative research system with internal and external researchers (universities, research institutes, and companies), with the aim of contributing to the maintenance and improvement of the quality of life of the people by efficiently returning the research results to society.

Summary of verification data of the National University Research Team

As typified by the term " Infectious disease panic," various infectious diseases continue to inflict serious damage on life, society, and the economy. In recent years, attention has been focused on the antiviral effects of various materials, and plant-derived ingredients such as EGCg have been actively studied. In this study, the antiviral effect of EGCg against human coronavirus (HCoV)-229E, which is closely related to SARS-CoV-2 and causes cold symptoms in humans, was measured using 50% Tissue Culture Infectious Dose (TCID50) was used as an indicator. The results showed that EGCg at a low concentration of 10 ppm had a certain inhibitory effect on the infection due to the synergistic effects of direct inactivation and adsorption inhibition.