Protective effect of different antioxidant agents in UVB-irradiated keratinocytes

Abstract

Skin cells can respond to UVB-induced damage either by tolerating it, or restoring it through antioxidant activation and DNA repair mechanisms or, ultimately, undergoing programmed cell death, when damage is massive. Nutritional factors, in particular, food antioxidants, have attracted much interest because of their potential use in new preventive, protective, and therapeutic strategies for chronic degenerative diseases, including skin inflammation and cancer. Some polyphenols, present in virgin olive oil, well tolerated by organism after oral administration, show a variety of pharmacological and clinical benefits such as antioxidant, anti-cancer, anti-inflammatory, and neuro-protective activities. Here, the protective effects of antioxidant compounds against UV-induced apoptosis have been described in HaCaT cell line. Human keratinocytes were pre-treated with antioxidants before UVB exposure and their effects have been evaluated by means of ultrastructural analyses. After UVB radiation, a known cell death trigger, typical apoptotic features, absent in control condition and in antioxidant alone-treated cells, appear. An evident numerical decrease of ultrastructural apoptotic patterns and TUNEL positive nuclei can be observed when natural antioxidants were supplied before cell death induction. These data have been confirmed by molecular investigation of caspase activity. In conclusion, this paper highlights antioxidant compound ability to prevent apoptotic cell death in human keratinocytes exposed to UVB, suggesting, for these molecules, a potential role in preventing skin damage.

Antioxidant and Cytoprotective Effects of (−)-Epigallocatechin-3-(3″-O-methyl) Gallate

“…Several reports have shown that antioxidants protect cells against UV irradiation [22,23,24]. The cytoprotective effect of 3″Me-EGCG against UVB irradiation was investigated.…”

Anthocyanins from Hibiscus syriacus L. Inhibit Oxidative Stress-Mediated Apoptosis by Activating the Nrf2/HO-1 Signaling Pathway

“…In particular, UV radiation causes the activation of several signaling pathways and exacerbates DNA damage by increasing ROS generation, which triggers apoptosis of keratinocytes in the epidermis [25]. Hence, many antioxidant compounds have been reported to protect epidermal keratinocytes against oxidative stress-mediated apoptosis [26], indicating that antioxidants increase keratinocyte survival in response to adverse oxidative stress and help to treat skin damage.…”

Cytoprotective, anti‐inflammatory, and antioxidant properties of high‐molecular‐weight hyaluronan enriched with red orange extract in human fibroblasts exposed to ultra violet light B irradiation

“…The protective effect of antioxidant molecules or botanical extracts has been widely demonstrated in human keratinocytes. Moreover, it has been shown that phytochemical antioxidants are able to reduce UVB‐induced apoptosis and inflammation in skin fibroblasts through the reduction of both DNA fragmentation and expression of pro‐apoptotic and inflammatory molecules . Indeed, one of the first responses upon UVB exposure is the induction of multiple cytokines .…”