It is now known that natural products of plant origin are very useful in the prevention and treatment of various diseases, combining effectiveness with low toxicity. Green tea is one of these, and thanks to the presence of polyphenols of which it is very rich, it makes a positive contribution to human and animal health because of its strong anti-tumor, antioxidant, antimicrobial and antiviral potential. For this reason we at Bict S.r.l. have designed and tested an extract particularly enriched in these active components, which we use as an ingredient in our best veterinary products, with antiviral action and able to stimulate the body’s immune system.
THE ACTIVE INGREDIENTS OF GREEN TEA
Green tea comes from the leaves of a plant called Camellia sinensis, the most characteristic and main polyphenol responsible for its properties is Epigallocatechin gallate (also known by the acronym EGCG), it represents about 59% of the total polyphenols present in dry green tea leaves. The other components are epicatechin gallate, epigallocatechin, epicatechin and catechin, present in different percentages.
The original cause of chronic viral infectious diseases is invasion by the virus, so it is of great importance to find effective antiviral treatments already active in the early stages. In recent years, green tea catechins have widely demonstrated inhibitory activities against various viruses, not only human but also animals such as fish, and even against some arboviruses, such as dengue virus (DENV) (Ismail et al., 2016), Chikungunya virus (CHIKV) (Weber et al., 2015) and Zika virus (ZIKV) (Carneiro et al., 2016).
GREEN TEA ANTIVIRAL ACTIVITY
In the case of human viruses, numerous studies have demonstrated the effectiveness of catechins against influenza A virus (IAV), an RNA virus belonging to the Orthomyxoviridae family. As early as 1949, Green and his collaborators demonstrated the antiviral activity of tea extracts against this virus, while more recently a group of Japanese researchers revealed that the anti-IV activity of green tea extracts, in particular EGCG, is related to the ability to inhibit the acidification of endosomes and lysosomes during infection (Imanishi et al., 2002). Surprisingly, clinical research has also contributed in this direction. In a double-blind, randomised, double-blind trial of 200 healthcare workers, it was verified that the consumption of catechin tablets for 5 months had a protective effect against the IAV virus compared to the placebo group (Matsumoto et al., 2011).
Another virus against which studies have demonstrated the effectiveness of green tea is the Epstein-Barr virus, a member of the herpes virus family. Some researchers have studied the anti-EBV effects of Epigallocatechin gallate and found that it not only suppresses the synthesis of some lytic proteins of the virus, but also reduces the transcription of the first genes activated after infection (Zhao et al., 2004).
Studying the effects and mechanisms of the activity of green tea catechins against viruses by conducting related studies in vivo or in animals is therefore fundamental. The discovery of natural antiviral extracts is a promising area and will continue to be an important development trend in the future because many more studies will be needed to prevent and eradicate viral infection and disease.