Protective Mechanisms of Green Tea Polyphenols in Skin

Table 1

Summary of effects of green tea polyphenols on skin.

GTPP protective effect	Cellular and/molecular response	References
UV protection	Inhibits UVB-induced MAPK activation and phosphorylation of ERK1/2, JNK and p38.	[51–54, 57]
	Attenuates nuclear transcription factors, c-Jun p53, and c-fos
Antioxidant	Free radical scavenging activity	[35, 48, 53, 54, 56, 57]
	Inhibits NOS, H2O2 production
	Prevents UVB-induced depletion of antioxidant enzymes: catalase, glutathione peroxidase, superoxide dismutase, and glutathione
	Inhibits UVB-induced LPO and protein oxidation
Anti-inflammation	Prevents UV-induced depletion of CD1a + LC and APC Inhibits UV-induced infiltration of monocytes, macrophages, neutrophils	[37, 45, 55, 57, 60]
	Protects UVB-induced immunosuppression via IL-12 production
	↓ in histamine release by mast cells
Anticarcinogenesis	Inhibits DNA damage.	[45, 48, 59, 60]
	Inhibits UV-induced CPD, 8-OHdG formation
	DNA repair enzyme activation
	Modulates transcriptions factors AP1, NFKB
	Inhibits tumor growth, progression and angiogenesis

LC: langerhans cells; LPO: lipid peroxidase; MAPK: mitogen-activated protein kinase; NOS: nitric oxide synthase.