The physiological role of green tea catechins

Microbiota in viral infection and disease in humans and farm animals

The Beneficial Effects of Green Tea on Sleep Deprivation-Induced Cognitive Deficits in Rats: The Involvement of Hippocampal Antioxidant Defense

Green tea is one of the most popular drinks consumed worldwide. Produced mainly in Asian countries from the leaves of the Camellia sinensis plant, the potential health benefits have been widely studied. Recently, researchers have studied the ability of green tea to eradicate infectious agents and the ability to actually prevent infections. The important components in green tea that show antimicrobial properties are the catechins. The four main catechins that occur in green tea are (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epigallocatechin-3-gallate (EGCG). Of these catechins, EGCG and EGC are found in the highest amounts in green tea and have been the subject of most of the studies. These catechins have been shown to demonstrate a variety of antimicrobial properties, both to organisms affected and in mechanisms used. Consumption of green tea has been shown to distribute these compounds and/or their metabolites throughout the body, which allows for not only the possibility of treatment of infections but also the prevention of infections.

Chapter 78 - Green Tea Polyphenols and Skin Protection: An Overview

BackgroundInfectious diseases continue to account for considerable illness and death worldwide, and emerging infectious diseases (EIDs) are a significant burden on global economies and public health. This study aimed to investigate the trends in infectious and parasitic disease (IPD) hospital admissions (HA) in England and Wales between 1999 and 2019.MethodsThis is an ecological study using publicly available data taken from the Hospital Episode Statistics database in England and the Patient Episode Database for Wales. Hospital admission data were collected for the period between April 1999 to March 2019. IPDHA were identified using the tenth version of the International Statistical Classification of Diseases system, diagnostic codes (A00–B99). The trend in hospital admissions was assessed using a Poisson model.ResultsThe overall annual number for IPD hospital admissions for various causes increased by 412.9%, from 151,336 in 1999 to 776,215 in 2019, representing an increase in hospital admission rate of 349.9% from 290.25 (95% CI 288.79–291.71) in 1999 to 1305.88 (95% CI 1303.00–1308.77) in 2019 per 100,000 persons: trend test, p < 0.01. The most common causes of infectious and parasitic disease hospital admissions were intestinal infectious diseases, other bacterial diseases, and other viral diseases, which accounted for 33.6, 27.5, and 23.8%, respectively. Patients aged 15 years and below accounted for 34.2% of the entire number of IPD hospital admissions, followed by the age group 15–59 years with 27.9%, the age group 75 years and above with 22.7%, and then the age group 60–74 years with 15.2%.ConclusionThere was an increase in the hospital admission rate due to infectious diseases in the UK from 1999 to 2019. The most common causes of infectious and parasitic disease hospital admissions were intestinal infectious diseases, other bacterial diseases, and other viral diseases.

Green tea catechins (GTCs) are a group of bioactive polyphenolic compounds found in fresh tea leaves (Camellia sinensis (L.) O. Kuntze). They have garnered significant attention due to their diverse health benefits and potential therapeutic applications, including as antioxidant and sunscreen agents. Human skin serves as the primary barrier against various external aggressors, including pathogens, pollutants, and harmful ultraviolet radiation (UVR). Skin aging is a complex biological process influenced by intrinsic factors such as genetics and hormonal changes, as well as extrinsic factors like environmental stressors, among which UVR plays a pivotal role in accelerating skin aging and contributing to various dermatological conditions. Research has demonstrated that GTCs possess potent antioxidant properties that help neutralize free radicals generated by oxidative stress. This action not only mitigates cellular damage but also supports the repair mechanisms inherent in human skin. Furthermore, GTCs exhibit anti-carcinogenic effects by inhibiting pathways involved in tumor promotion and progression. GTCs have been shown to exert anti-inflammatory effects through modulation of inflammatory signaling pathways. Chronic inflammation is known to contribute significantly to both premature aging and various dermatological diseases such as psoriasis or eczema. By regulating these pathways effectively, GTCs may alleviate symptoms associated with inflammatory conditions. GTCs can enhance wound healing processes by stimulating angiogenesis. They also facilitate DNA repair mechanisms within dermal fibroblasts exposed to damaging agents. The photoprotective properties attributed to GTCs further underscore their relevance in skincare formulations aimed at preventing sun-induced damage. Their ability to screen UV light helps shield underlying tissues from harmful rays. This review paper aims to comprehensively examine the beneficial effects of GTCs on skin health through an analysis encompassing in vivo and in vitro studies alongside insights into molecular mechanisms underpinning these effects. Such knowledge could pave the way for the development of innovative strategies focused on harnessing natural compounds like GTCs for improved skincare solutions tailored to combat environmental stresses faced by the human epidermis.

Chapter 105 - Green Tea and its Main Catechin, Epigallocatechin-3-Gallate, Provide Parasitic Protection

Introduction: Sinecatechins was the first botanical drug licensed for treatment in humans in the US. It is approved for the topical treatment of external genital and perianal warts. Some properties of the polyphenolic components included in sinecatechins suggest additional therapeutic potential for other skin diseases.Areas covered: Studies and articles describing therapeutic application of sinecatechins or green tea polyphenols in viral and proliferative skin diseases or investigating molecular activities relevant for the mode of action were identified by a PubMed search using ‘sinecatechins’, ‘green tea polyphenols’, ‘polyphenon E’ and ‘EGCG’, each combined with ‘skin cancer’ and ‘genital warts’ as search criteria. Although a number of molecular mechanisms of green tea polyphenols were described, the exact mode of action operative in regression of genital warts is not yet clear. It may involve both antiproliferative, pro-apoptotic and antiviral activities that probably also account for efficacy against other skin disorders.Expert opinion: In addition to treatment of skin tumors, sinecatchins may also be used to protect against photocarcinogenesis. Considering antioxidative properties of polyphenols and the capability to enhance DNA repair, sinecatechins appears attractive for primary prevention of nonmelanoma skin cancer either as additive in sunscreens or as dietary supplement for oral administration.

INTRODUCTION: Humans have innate and adaptive defense mechanisms that, collectively, protect us against diseases and infections. But a malfunction of our immune system may cause harm in the form of autoimmune diseases. CASE DESCRIPTION/METHODS: We present a 29 year old female with no PMH who sought outpatient evaluation for new onset jaundice. With the intent of losing weight, the patient followed a strict diet, consisting of apples and water with one ‘cheat’ meal per week. In conjunction, patient reported using a daily herbal extract with containing green tea and green coffee bean extract. There was no family history of liver or autoimmune disease. After 4 months, she developed nausea, vomiting and jaundice. She was hemodynamically stable and afebrile. With the exception of jaundice the physical examination was unremarkable. Imaging (CT and MRI) of the liver revealed periportal edema. Initial laboratory evaluation showed ALT 960, AST 1162, T BR 17.3 & INR 1.9. HBV, HCV, HSV, HIV, EBV and CMV, Wilson’s disease and alpha 1 antitrypsin deficiency were ruled out as the cause of the patient’s acute liver injury. ANA titer was 1:1280 with a speckled pattern. Antimitochondrial, smooth muscle and liver kidney microsomal antibodies were negative. Due to persistent decompensation, liver biopsy was done with extensive hepatic necrosis. She was ultimately diagnosed with autoimmune hepatitis and treated with corticosteroids and later azathioprine. DISCUSSION: Although acute liver injury induced by green tea consumption has been described, the association with autoimmune hepatitis has been rarely reported. Green tea leaves contain polyphenols, flavonols and catechinis. The polyphenols have antioxidant, anticarcinogenic, anti-inflammatory, thermogenic and antimicrobial properties. Green tea extract has been associated with acute hepatitis and fulminant hepatic failure. The mechanisms leading to cytotoxicity include mitochondrial membrane destruction and induction of reactive oxygen species. Patients with autoimmune hepatitis may have symptoms of jaundice with hypergammaglobulinemia and positive serum antibodies (ANA, smooth muscle and liver kidney microsomal). The liver develops inflammation, necrosis and fibrosis for which therapy with corticosteroids and azathioprine are used. These findings were noted in our patient after several months of green tea and green coffee bean consumption. Therefore we hypothesize that green tea may, in rare circumstances, be the trigger of autoimmune hepatitis.

Tea and health: a historical perspective.

In children, a male predominance in the incidence of symptomatic disease has been reported for some infectious agents and not for others. Not only are the factors underlying these sex differences poorly understood, but it is also not clear why the differences are described only for selected infectious diseases. In this study of sex- and age-specific incidence of infectious diseases in children, a possible explanation for the inconsistencies in the literature was explored. The sex ratio in reported disease incidence in Israel during a period of about 20 years was examined for various viral and bacterial infections. In addition, an hypothetical mathematical model was developed which assumes increased susceptibility to infectious disease (such as in relative immune deficiency) in a proportion of males. In children aged under 4 years, a higher incidence among males was consistently observed for all diseases, and the sex ratio varied between 1.16 (95% confidence interval (CI): 1.13-1.18) for shigellosis to 1.98 (95% CI: 1.79-2.17) for viral meningitis. The highest ratios were associated with the diseases which tend to present asymptomatically most often, which is consistent with the predictions of the model. The male excess in symptomatic disease appears to be present for most infectious diseases and this should be taken into account in studies comparing observed disease incidence between groups with different sex ratios. The inconsistencies in reports on the excess male morbidity for infectious diseases may be due to variations in symptomatic to asymptomatic infection ratios.

Ultraviolet (UV) radiation is one of the key contributors to the deterioration of skin structure and function. Its harmful effects include premature aging, hyperpigmentation, and increased risk of skin cancer. One of the underlying mechanisms of this damage is the formation of free radicals, which trigger oxidative stress, compromise cellular integrity, and reduce the skin’s natural defense capacity. The use of skin protection products such as sunscreen serves as a preventive measure in daily skincare routines. This community service (PkM) activity was conducted through an interactive model of education and demonstration, aimed at enhancing public knowledge and awareness regarding the benefits of natural antioxidants available in sunscreen gel formulations derived from green tea leaf extract. The program was designed with an educational and participatory approach, in which the materials were delivered through theoretical explanations and simple practical demonstrations. The participants consisted of 25 individuals, both male and female, aged between 17 and 40 years, residing in the Lubuk Pakam area. The results of the activity showed a significant improvement in participants’ knowledge, with an average post-test score of 89.98 compared to a pre-test score of 56.05 indicating a substantial knowledge gain of 33.93 points, which falls into the "very high" category. This community outreach proved effective in increasing public understanding of the use of natural antioxidants in sunscreen products. Furthermore, participant satisfaction was remarkably high, with an average satisfaction rating of 96.4%, categorized as "Very Satisfied." In conclusion, this PkM activity successfully enhanced the participants’ knowledge regarding natural skin protection strategies, and participants expressed strong satisfaction with the implementation of the program.

The main environmental source for skin damage is ultraviolet (UV) radiation. Many adverse effects have been recognized as the result of prolonged cutaneous exposure to solar ultraviolet radiation, such as erythema, edema, apoptosis, hyperplastic responses, photo-aging, and skin cancer development. Green tea provides photo-protection against UV radiation through many mechanisms including anti-inflammatory, immunomodulatory, and antioxidant properties. The aim of this study was to evaluate the effect of green tea in reducing epidermal thickness on mouse’s skin exposed to UVB irradiation. Thirty mice (Mus musculusspecies, BALB/c strain) underwent this study and were divided into 3 groups: control group (n=10mice), without UVB exposure and green tea administration; exposure group (n=10mice), which were exposed to UVB light only; and treatment group (n=10mice), which were exposed to UVB light and treated with 1 mL of green tea through oral gavage. Mice from both groups (exposure and treatment) were subjected to UVB irradiation 4 days/week (20 minutes/day, 4 weeks). It concluded that oral administration of green tea was provided photo-protection against UVB induced hyperplasia; therefore, it can be regarded as a natural alternative for photo-protection.

Green tea plant ( Camellia sinensis L . Kuntze) were examined in this study were taken from green tea products Cap Head Djenggot, from the area of Solo, Central Java. This plant thrives in the area of Green Tea plantation in the Solo area. For identification of the content of flavonoids in green tea leaves can be done Thin Layer Chromatography is accompanied by a color reaction.Spotting obtained detected with ammonia vapor is then observed with UV light UV 254 nm and 366 nm. In observation using a 254 nm UV light there is a blackish brown spots on the fraction of water-chloroform, the chloroform fraction of the spots are a light green color, and the n-butanol fraction contained a brown patches muda.Dengan using 366 nm UV rays are one dark brown spots on the fraction of water-chloroform, the chloroform fraction contained patches of light green color, and the n-butanol fraction contained a light brown spots.Based on data obtained from the reaction of color and Thin Layer Chromatography showed that the compound contained flavonoids in green tea leaves.

Background The zebrafish represents the simplest and most convenient vertebrate model for undertaking large screens because of its small size, rapid reproduction time and transparency of the body. Here, we adopt a well-established model of inflammation in zebrafish to assess the impact of Epigallocatechin-3-Gallate (EGCG), the main catechin in green tea. Method Tg (MPX:GFP) or Tg (MPX:mCHERRY) transgenic zebrafish were used, bearing GFP- or mCherry-tagged neutrophils, respectively. 4dpf embryos were anesthetized, and inflammation was induced by sterile tailfin-resection. The inflamed groups were separated into those that were non-treated or exposed to EGCG from 0 – 600 uM for 6 hours. 10 fish per group were then mounted alive in methyl cellulose for wide-field fluorescence imaging and analysis was done using ImageJ. Animation of neutrophil migration or accumulation was recorded using an inverted fluorescence confocal microscope till 6-hours after resection. To examine the mechanistic basis of EGCG’s effect, 37 zebrafish inflammatory genes were studied using qPCR. Results The static accumulation of neutrophils at the resection site was highly elevated after wounding (n=32, p&amp;lt;0.0001), and this accumulation was reduced significantly by 31% and 43%, respectively, after exposure to EGCG 300 uM (p&amp;lt;0.05) and 600 uM (p&amp;lt;0.01). Dynamic neutrophil tracking studies are in progress. qPCR studies revealed 6 signature genes in the IL-1 beta pathway to be significantly down-regulated at least 2-fold after EGCG treatment. Conclusion EGCG suppresses inflammation in zebrafish through similar biochemical pathways as in other species. This novel animal model allows facile screening of inflammatory modulators in real-time.