Molecular mechanisms of green tea polyphenols with protective effects against skin photoaging

Abstract

Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.

Natural Polyphenols for Acne Vulgaris: Clinical Evidence and Biological Mechanisms

“…Due to the potential role for skin protection [17,18], green tea polyphenols, especially EGCG, have recently been increasingly used in various cosmeceutical preparations. Figure 3 shows the chemical structure of EGCG and the picture of an EGCGcontaining cosmeceutical cream.…”

Molecular Mechanisms of Skin Aging and Rejuvenation

“…Epigallocate-chin-3-gallate (EGCG), which is a polyphenolic constituent of GTP, has been reported to have the inhibitory effect on the expression and activity of MMPs and leukocyte elastase, which has an important role in tumor invasion and metastasis. In addition, GTPs have been shown to decrease the levels of oxidative stress, prevent UV radiation-induced DNA damage, their potential immunosuppressive effects, and skin cancers [72,73]. Like GTPs, other botanic extracts have been described to contain potent antioxidant components, including curcumin (turmeric), silymarin (milk thistle), apigenin, resveratrol (red grape), and genistein (soy bean) [74].…”

Ternary deep eutectic solvent magnetic molecularly imprinted polymers for the dispersive magnetic solid‐phase microextraction of green tea

“…Green tea has been used for thousands of years and investigated because of the pharmacological effects of its bioactive compounds, including antioxidative activity, antimutagenic, and anticancer effects . Previous research examined the various bioactive compounds in green tea extracts, such as phenolic compounds, catechins, chlorophyll, caffeine, amino acids, vitamins, and other nutrients . The biological activity of these compounds has been associated with a reduced risk of severe illnesses, such as cancer, cardiovascular, and neurodegenerative diseases.…”

“…Green tea has been used for thousands of years and investigated because of the pharmacological effects of its bioactive compounds, including antioxidative activity, antimutagenic, and anticancer effects [1,2]. Previous research examined the various bioactive compounds in green tea extracts, such as phenolic compounds, catechins, chlorophyll, caffeine, amino acids, vitamins, and other nutrients [3,4]. The biological activity of these compounds has been associated with a reduced Article Related Abbreviations: AM, Acrylamide; ChCl, Choline chloride; DM-SPME, Dispersive magnetic solid-phase extraction; EG, Ethylene glycol; GL, Glycerol; HBA, hydrogen bond acceptor; HBD, hydrogen bond donor; MAA, Methacrylic acid; MIP, Molecularly imprinted polymer; OA, Oxalic acid; PG, Propylene glycol; TDES, Ternary deep eutectic solvent; XRD, X-ray diffraction risk of severe illnesses, such as cancer, cardiovascular, and neurodegenerative diseases.…”