Green Tea
Author – Mahek Lakhyani
Roll no. – MBA_FIN_10005

INTRODUCTION

Camellia sinensis L. is popularly known as green tea, and is one of the most consumed
beverages in the world. There are many primary metabolites, such as organic acids,
amino acids, and carbohydrates, present at different concentrations in the tea leaves. In
addition, secondary metabolites, which include alkaloids and polyphenols, are also present
that influence many biological and pharmacological activities, such as anti-microbial,
anti-tumor, and anti-oxidative properties. In addition, the quality of the tea leaves is
determined by these metabolites, which are influenced by different factors such as species
type, geographical status, and climate factors.(Emwas, A. M., Al-Rifai and others 2021)

MATCHA GREEN TEA

Japanese matcha is a type of powdered green tea, grown in a traditional way. Shading of the plants during the growth period enhances the processes of synthesis and accumulation of biologically active compounds, including theanine, caffeine, chlorophyll and various types of
catechins. Green tea contains four main catechins, i.e., (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG), of which the latter is the most active and abundant and matcha is their best condensed source. Due to its unique chemical composition and prized flavour, which sets it apart from other tea beverages, it is considered the highest quality tea. Its health-promoting properties are attributed to the high content of antioxidant and anti-inflammatory substances. Studies confirming the high antioxidant potential of tea beverages claim that it originates from the considerable content of catechins, a type of phenolic compound with beneficial effects on human health. Due to its potential for preventing many diseases and supporting cognitive function, regular consumption of matcha may have a positive effect on both physical and mental health. (http://dx.doi.org/10.3390/molecules26010085)

SARS-CoV-2

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, Ohgitani, E., Shin-Ya and others 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.(Ohgitani, E., Shin-Ya and others 2021)

COVID

Epigallocatechin gallate (EGCG) is a major catechin found in green tea, and there is mounting
evidence that EGCG is potentially useful for the treatment of coronavirus diseases, including
coronavirus disease 2019 (COVID-19). Coronaviruses encode polyproteins that are cleaved by 3CL protease (the main protease) for maturation. Therefore, 3CL protease is regarded as the main target of antivirals against coronaviruses. EGCG is a major constituent of brewed green tea, and several studies have reported that EGCG inhibits the enzymatic activity of the coronavirus 3CL protease. Moreover, EGCG has been reported to regulate other potential targets, such as RNA-dependent RNA polymerase and the viral spike protein. (http://dx.doi.org/10.3390/life11030197)

CANCER

Green tea has been shown to have beneficial effects on human health such as anti-cancer, anti-obesity, anti-diabetic, anti-cardiovascular, anti-infectious and anti-neurodegenerative effects . (-)-Epigallocatechin gallate (EGCG) is the most abundant catechin in green tea and believed to be mostly responsible for these biological effects .A cup of green tea typically brewed from 2.5 g of tea leaves contains 240–320 mg of catechins, of which EGCG accounts for 60–65%.The studies done by Hayakawa, S., Ohishi, T. and others have provided evidence to show favorable effects on some types of cancer such as breast, colon, lung and blood cancers by green tea consumption.(Hayakawa, S., Ohishi, T. and others 2020)

INFLUENZA

This meta-analysis shows that regular green tea consumption, whether by taking GTC
capsules, drinking, or gargling, can prevent influenza, although the study populations
were from different countries, the treatment regimens were different, and the number of
studies on tea catechins against influenza was limited. Further studies are needed to better
investigate the processes described for individual and collective treatment with green tea.
Future large-scale studies are needed to establish or confirm their clinical efficacy. Most
importantly, it must be clearly emphasized that green tea catechins cannot replace standard
influenza vaccination or treatment. Nevertheless, their beneficial effects may support
common influenza prevention. (Rawangkan, A., Kengkla, K. and others 2021)

ANTIVIRAL EFFECTS OF GREEN TEA

EGCG, as the major secondary metabolite polyphenol in Green Tea (Camellia sinensis), has been
confirmed to be a multifunctional bioactive molecule with potential for anti-infective,
anti-proliferation and antiviral effects. EGCG acts antiviral functions in different stages of infection for both nuclear viruses and cytoplasmic viruses, and so is considered to be a potential alternative agent for multiple viral diseases. The antiviral effects of EGCG on DNA and RNA viruses have been proven in in vitro experiments abundantly. (Ying-Qi, W., Qing-Sheng and others 2021)

OBESITY

Several observational human studies have indicated that tea or green tea consumption
can exert beneficial effects on obesity. As per the findings of the study, it showed that green tea and GTE significantly decreased body weight and BMI . These results further indicated the therapeutic effects of green tea catechins (GTCs) in improving MetS characteristics in obese patients. A double-blind parallel multicenter trial in 240 subjects by Nagao et al. observed
that participants who consumed a GTC 583 mg/day dose exhibited greater decreases
in body weight, BMI, body fat ratio, body fat mass, WC, hip circumference, visceral fat
area (VFA), and subcutaneous fat area when compared to those who consumed a GTC
96 mg/day dose. According to the studies, EGCGs are beneficial for weight management in patients with Down syndrome. (http://dx.doi.org/10.3390/molecules26020453)

MANAGEMENT OF DIET

The average consumption of green tea infusions, assumed to be 3–4 cups (1 L) a day, may be a significant source of phenolic compounds and manganese in the diet, because it provides the body with an amount of these components that significantly exceeds the levels recommended for daily consumption. The study done by Joanna Klepacka El˙zbieta To´ nska, Ryszard Rafałowski and others also confirmed that the antioxidant effect of tea infusions results mainly from the presence of phenolic compounds and manganese. However, this antioxidant activity is also associated with the occurrence of magnesium and potassium. (http://dx.doi.org/10.3390/molecules26051487)

PREVENTION OF DEPRESSION

A Chinese population-based study done by Yao, Y., Chen, H., Chen, L., Sang-Yhun Ju and others demonstrated that a higher consumption of tea, including green, fermented, floral tea, was inversely associated with the prevalence of depressive symptoms, while the association was particularly pronounced among floral tea drinkers. These findings suggest that the consumption of various types of tea may be potentially beneficial for the prevention of depressive symptoms. (Yao, Y., Chen, H. and others 2021)

CONCLUSION

Camellia sinensis L. is popularly known as green tea. It comes in different types. The richest form of Green Tea is the Japanese Matcha Green Tea. It has proven to have many health benefits such as anti-cancer, anti-obesity, anti-diabetic, anti-cardiovascular, anti-infectious and anti-neurodegenerative effects. It helps to cure influenza. It also helps to manage weight and reduce obesity. It has calming and soothing effects and thus helps in the prevention of depressive symptoms.

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Hayakawa, S., Ohishi, T., Miyoshi, N., Oishi, Y., Nakamura, Y., & Isemura, M. (2020). Anti-cancer effects of green tea epigallocatchin-3-gallate and coffee chlorogenic acid. Molecules, 25(19), 4553. doi:http://dx.doi.org/10.3390/molecules25194553

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Ohgitani, E., Shin-Ya, M., Ichitani, M., Kobayashi, M., Takihara, T., Kawamoto, M., . . . Mazda, O. (2021). Rapid inactivation in vitro of SARS-CoV-2 in saliva by black tea and green tea. Pathogens, 10(6), 721. doi:http://dx.doi.org/10.3390/pathogens10060721

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