However, the DNA is quite stable, so the cancer induction rate is much lower than expected, considering the number of oxidative events [145]. The skin’s capacity for antioxidant self-protection rapidly decreases during aging. In order to restore the antioxidant defense properties of the skin, there is a constant need for provision of antioxidant compounds from exogenous sources, such as cosmetics or food [104]. An important example of the polyphenol, supplied from diet is epigallocatechin-3-gallate (EGCG)—the compound common in the green tea. As previously mentioned the mechanism of its action refers to the inhibition of MMPs. Moreover EGCG is very effective in improving the skin condition by the reactivation of the damaged or old cells due to the DNA protection and production of more energy in the cells
Plant phenolic compounds are widely known for their antioxidant properties. As already mentioned, the aromatic structure of polyphenols is the significant feature in oxidative stress, namely in preventing the formation and scavenging of reactive oxygen (ROS) and nitrogen species (RNS). According to Almeida et al., photoaging may be attenuated by phenolic metabolites in the presence of Castanea sativa polyphenols (e.g., ellagic acid). Incubation of HaCaT cells with C. sativa leaf extract reduced the UV-induced damage in DNA. The previous research suggests that the protective mechanism is based on direct antioxidant action
activation of nuclear factor erythroid-related factor-2 (NRF2), a redox-sensitive transcription factor which is known to be stimulated by many phytochemical compounds [144]. The amount of UV-damaged DNA was also reduced after treatment with polyphenols (mainly anthocyanins) from berries: blackberry (Rubus adenotrichos), honeyberry (Lonicera caerulea) and bilberry
(Vaccinium myrtillus). However, in comparison to C. sativa activity, after incubation with berry juices not only were the DNA mutations repaired (reduction of cyclobutane pyrimidine dimers) but also severely modified cells rapidly led to the apoptosis
pathway (altered expression of caspase-3, -8, -9 genes). Apart from the cell culture, the activity of phenolics from blackberry juice was determined in a 3D skin model, while honeyberry juice activity was determined on hairless mice skin [146,147,148]. The photodamage of keratinocyte DNA caused by H O -induced ROS was also
inhibited by oxyresveratrol and kuwanon O from Morus australis. The most noticeable was the reduction of pyrimidine cyclobutane dimers after treatment with M. australis extract [149]. The protection activity of the plant extracts from the UV-induced DNA damage was presented in the