64 JOURNAL OF COSMETIC SCIENCE The clinical study results observed 3 distinct groups: (1) The commercial SPF 50 sunscreen showed the highest protection (2) black tea and green tea gels were effective in protecting against UV erythema and (3) the vehicle gel, control gel, and caffeine gel (which had no UV protection). The p values obtained after multiple comparison post hoc tests were presented in Table V. In terms of UV protection, there was no statistical difference between black tea and green tea gels. No erythema reducing activity was found in control and vehicle gel areas after the exposure to UV and no erythema reducing activity was found after the exposure to UV. The UV absorbance of all gels was examined with a Transpore® test. The results are given in Figure 4. DISCUSSION In our previous studies, we reported the erythema prevention effect of tea extracts due to UV exposure of the skin (13,14). In this study, with a larger group (n =21) of volunteers, we demonstrated the UV protective effect of black or green tea gel formulations. We also recently reported the anabolic effect of green tea extract in the cell cultures of keratinocytes (20). The literature is rich with the health benefits of tea or tea extracts, especially on Table IV The Erythema Grades Obtained Based on Formulas Day Black tea gel Green tea gel Caffeine gel Vehicle gel Control SPF 50 sunscreen Mean ± SD 1 1.81 ± 1.5 1.76 ± 1.6 5.62 ± 2.0 6.57 ± 1.6 6.62 ± 1.8 0.10 ± 0.30 2 1.29 ± 1.3 1.43 ± 1.6 5.48 ± 2.0 6.48 ± 1.7 6.52 ± 1.6 0.00 ± 0.00 3 0.67 ± 1.1 1.05 ± 1.6 4.10 ± 2.5 4.86 ± 2.3 5.05 ± 2.0 0.00 ± 0.00 Figure 3. The change in erythema severity for each formula by time.

65 PRELIMINARY SCREENING STUDY WITH TEA FORMULATIONS the skin. UV enhances skin damage mainly by increasing the production of ROS and by raising the levels of matrix metalloproteases that degrade the collagen and elastin fibers of the skin matrix. These reactions lead to wrinkle formation and reduced integrity of the skin, which are overall defined as photoaging (5). It is confirmed with numerous in vitro studies and animal models that topical treatment with green tea polyphenols reduce UV-induced oxidative stress and inflammatory response (5). It has been reported that the suggested positive effects of tea extracts were also determined with systemic treatment. The signs of UV-induced photoaging (e.g., wrinkle formation were decreased and collagen synthesis) were promoted in mice fed with green tea seed extracts (21). It can be suggested that the tea plant (C sinensis) has a wholistic influence on the skin consisting of anti- inflammatory, antioxidative, immunoregulatory, antiproliferative, DNA repairing, and anticancerogenic effects. Green tea extract was found to demonstrate anabolic effects on hyaluronic acid, collagen, and elastin by causing upregulation of hyaluronan synthase-2, and downregulations of matrix metalloproteinase-9 and elastase gene expressions (20). On histologic examination, skin treated with green tea extracts decreased the number of sunburn cells and protected epidermal Langerhans cells from the detrimental effects of UV (22). Tea components significantly delay the signs of skin aging through the inhibition of lipoxygenase, metalloproteinase, hyaluronidase, and collagenase (23). It is reasonable to claim that these results are mainly because of the plant’s strong antioxidant activity associated with its phenolic and flavonoid ingredients (Tables II and III). In the light of the literature data and the results of this study, with routine use of the tea extracts in the form of cosmetic formulations daily, the concentration of tea actives will increase in the skin, and it can be speculated that flavonoids and polyphenols will protect the skin, both from the effects of acute UV damage by absorbing the incoming UV radiation. Additionally, this might contribute to repairing the chronic UV damage that causes collagen destruction and photoaging. This study indicates that both forms of tea, black or green, have almost similar Table V The Multiple Comparisons for Formulas Day Black tea Green tea Caffeine Vehicle Control SPF 50 Black tea 1 2 3 NA Green tea 1 2 3 NS NS NS NA Caffeine 1 2 3 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 NA Vehicle 1 2 3 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 NS NS NS NA Control 1 2 3 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 NS NS NS NS NS NS NA SPF 50 1 2 3 =0.0083 NS NS =0.0114 =0.0332 NS 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 NA NA: Nonapplicable NS: Nonsignificant.