Inhibition of UVB-Induced Skin Tumor Development by Drinking Green Tea Polyphenols Is Mediated Through DNA Repair and Subsequent Inhibition of Inflammation

Abstract

Consumption of green tea polyphenols (GTPs) in drinking water prevents photocarcinogenesis in mice; however, the molecular mechanisms underlying this effect have not been fully elucidated. Using interleukin (IL)-12p40 knockout (IL-12-KO) mice and their wild-type counterparts and an established photocarcinogenesis protocol, we found that although administration of GTPs (0.2%, w/v) in drinking water significantly reduced UVB-induced tumor development in wild-type mice, this treatment had a non-significant effect in IL-12-KO mice. GTPs resulted in reduction in the levels of markers of inflammation (COX-2, PGE2, PCNA, cyclin D1) and proinflammatory cytokines (TNF-α, IL-6, IL-1β) in chronically UVB-exposed skin and skin tumors of wild-type mice but less effective in IL-12p40-KO mice. UVB-induced DNA damage (cyclobutane pyrimidine dimers) was resolved rapidly in GTPs-treated wild-type mice than untreated wild-type mice and this resolution followed the same time course as the GTPs-induced reduction in the levels of inflammatory responses. This effect of GTPs was less pronounced in IL-12-KO mice. The above results were confirmed by treatment of IL-12-KO mice with murine rIL-12 and treatment of wild-type mice with neutralizing anti-IL-12 antibody. To our knowledge this is previously unreported that prevention of photocarcinogenesis by GTPs is mediated through IL-12-dependent DNA repair and a subsequent reduction in skin inflammation.

PROTECTIVE EFFECT ETHANOLIC EXTRACT OF Boesenbergia pandurata (ROXB.) Schlecht. AGAINST UVB-INDUCED DNA DAMAGES IN BALB/C MICE

“…The CPDs expression was found in cytoplasm and nucleus cells of epidermal and dermal layer in UVB-exposed group (Figure 1). It was showed that UVB exposure penetrated into dermal layer skin mice, this result consistent with the previous study when UVB (180mJ/cm 2 ) exposed on the SKH-1 hairless, C3H/HeN and IL-12p40KO mice (Meeran et al, 2009;Afag et al, 2010). UV-B radiation can penetrate the skin to depth approximate 160-180 µm.…”

“…Highest expression of CPDs showed at 2 hours after UVB exposure ( Figure 2). Balb/c mice showed less sensitive to UVB irradiation than hairless mice which had the highest CPDs expression at 0.5h after 180mJ/cm 2 UVB irradiation on female C3H/HeN and IL-12p40 KO mice (Meeran et al, 2009) and at 1h after a single dose of 3xMED (Minimal Erythema Dose) of Solar Simulator UV in hairless mice (Widyarini, 2006). These indicated that UVB-induced CPDs formation was influenced of wave length, intensity of radiation and animal sensitivity.…”

Pleural fluid analysis of lung cancer vs benign inflammatory disease patients

“…We decided to analyse these markers as they belong to three different marker groups that may be related to cancer and/or to inflammatory diseases. p27, Skp2, Cox2, CycD1 and Ki67 are considered as tumour and/or proliferation markers (Huang et al, 2003;Siggelkow et al, 2004;Adjei, 2005;Vig-Varga et al, 2006;Garg et al, 2008;Park et al, 2008;Chang et al, 2009;Meeran et al, 2009;Mukhopadhyay et al, 2009), ImAnOx and carbonyls are oxidative markers (Nyström, 2005;Bahar et al, 2007) and MMP-9, -3 and -2 are MMPs that are expressed in various pathological processes such as inflammation and cancer and also in response to infections (Korpos et al, 2009;Oikonomidi et al, 2009;Vanlaere and Libert, 2009). Enhanced oxidative stress characterises both inflammation and cancer; all other markers analysed were also shown previously to be associated with inflammation, as well as with oxidative stress, presumably mediated through the activation of NF-kB (Huang et al, 2003;Vig-Varga et al, 2006;Park et al, 2008;Gonda et al, 2009;Karalis et al, 2009;Ku et al, 2009;Perricone et al, 2009;Víctor et al, 2009).…”

Paulownia tomentosa (Princess Tree) Extract Reduces DNA Damage and Induces DNA Repair Processes in Skin Cells

“…To adapt to the continuous insult from excessive sun light exposure, plants developed physical, enzymatic and non-enzymatic mechanisms to not only protect but also to repair the damage done from indiscriminate exposure of UV radiation. Some of the secondary metabolites for example polyphenols such as green tea polyphenols have been studied [37]. Green tea polyphenols plays protective role by mediating DNA repair and reduction in skin inflammation.…”