view injury and therefore the array of molecules they produce or induce their neighbors to produce. The injured cell has at least four alternatives: complete repair, autophagy, apoptosis or necrosis. Each of these pathways has a consequence to the surrounding tissue. An example of complete repair may be the excision-repair proteins for damaged DNA that may be going on continuously without upsetting the cellular environment. Additional stress to the cell is a reactive oxygen species (ROS) assault, which could be quenched by the cell’s store of antioxidants or by the exogenous antioxidants applied to the skin or consumed. This simplistic explanation needs to be expanded. Cell necrosis is the most inflammatory path for the injured cell with release of all the contents initiating myriad inflammatory pathways and immune activation. This kind of pathway probably accounts for the exacerbation of lupus after acute UV damage. Apoptosis or programmed cell death is the least inflammatory method of removing non-repairable cells as represented by the sunburn cell. The combination of resveratrol, green tea pholyphenols, and caffeine in our product proved effective in reducing redness. Each of these three compounds yields an acclamatory effect on individual cells in the surrounding environment, which may account for the observed benefits.
Green tea polyphenols (GTPs) are antioxidants shown in mice to protect against skin inflammation, associated tumorigenesis15,16 and phototoxicity induced by psoralen plus UV-A radiation.17 The polyphenol portion of green tea (the catechins) includes epicatechin, epicatechin-3-gallate, epigallocatechin, and epigallocatechin-3-gallate derivatives. When only the catechin portion of green tea is administered topically in mice, epigallocatechin-3-gallate (EGCG) protects best in a photocarcinogenesis model.18 Because of this and similar models, EGCG is regarded as the most effective catechin.19 It is important to remember that the epidemiology is for green tea and not any individual molecules. Surrogates are valid for their models. They are used for their expediency. Intentionally, the studied product uses all of the molecules in green tea leaves that would be present in the beverage on which the epidemiology is based.
Another approach to discerning mechanisms by which the combination product of the present study reduces facial redness involves pathways of inflammation. Facial redness may occur in a variety of inflammatory dermatologic disorders.20 Since the molecular targets of each component are not identical, the components may act independently or synergistically to reduce cutaneous inflammation. All three of the components in our product have been shown to improve or protect against UV-induced skin damage. Exposure of the skin to UV radiation induces formation of ROS, which leads to inflammatory responses associated with a variety of skin disorders, including cancer. Inflammatory responses are characterized by erythema, edema, hyperplastic responses, and increases in blood vessel permeability. Both topical GTP-application and GTPs in drinking water reduce inflammation.21 One study22 on the anti-inflammatory component of GTPs showed that, after pretreating human skin with green tea extract and then exposing the treated area to solar-simulated light, the green tea extract inhibited UV-induced erythema in a dose-dependent manner, reduced the number of sunburn cells, and protected the epidermal Langerhans cells. Resveratrol, as a natural polyphenol, is also a pigment. This property allows it to absorb UV radiation, and when applied topically, it can reduce the penetration of UV radiation into the skin.23 In this way, topical resveratrol acts as a natural sunscreen and reduces the inflammation and oxidative damage associated with UV exposure. Furthermore, pre-treatment of keratinocytes with resveratrol increases cell survival after these cells have been exposed to UV radiation.24 This is also associated with a reduction in the production of ROS, and subsequent anti-inflammatory effects. Green tea phenols add to this anti-inflammatory effect. GTPs can inhibit the UV-induced infiltration of neutrophils and macrophages.25 In our product, this effectiveness is further supplemented by caffeine. Topical caffeine has been shown to protect against UV damage in mice by eliminating UV-damaged keratinocytes,26 and subsequently inhibiting skin
