The Polyphenol Chlorogenic Acid Attenuates UVB-mediated Oxidative Stress in Human HaCaT Keratinocytes

Abstract

We investigated the protective effects of chlorogenic acid (CGA), a polyphenol compound, on oxidative damage induced by UVB exposure on human HaCaT cells. In a cell-free system, CGA scavenged 1,1-diphenyl-2-picrylhydrazyl radicals, superoxide anions, hydroxyl radicals, and intracellular reactive oxygen species (ROS) generated by hydrogen peroxide and ultraviolet B (UVB). Furthermore, CGA absorbed electromagnetic radiation in the UVB range (280–320 nm). UVB exposure resulted in damage to cellular DNA, as demonstrated in a comet assay; pre-treatment of cells with CGA prior to UVB irradiation prevented DNA damage and increased cell viability. Furthermore, CGA pre-treatment prevented or ameliorated apoptosis-related changes in UVB-exposed cells, including the formation of apoptotic bodies, disruption of mitochondrial membrane potential, and alterations in the levels of the apoptosis-related proteins Bcl-2, Bax, and caspase-3. Our findings suggest that CGA protects cells from oxidative stress induced by UVB radiation.

Polyphenols and DNA Damage: A Mixed Blessing

“…Kumar et al [79] found that a combination of ellagic acid with curcumin (25 μM each) caused SBs while the separate compounds had no significant effect. A decrease in (background) SBs with epigallocatechin gallate or epicatechin gallate was reported by Durgo et al [36] at 48 but not 72 h. At more reasonable concentrations, the results are mixed: decreases in UV(B)-induced SBs [70] and cyclobutane pyrimidine dimers [72]; decreases in H 2 O 2 -induced SBs and MN [74]; a decrease in SBs induced by cumene hydroperoxide [75]; but SBs and Fpg-sites increased in tetradecanoyl phorbol acetate (TPA)-stimulated neutrophils [78] and an increase in SBs with ellagic acid in prostate cancer cells was reported by Vanella et al [73] at concentrations of 9 μM in one of the cell lines but higher concentrations in two other lines.…”

Polyphenols as active ingredients for cosmetic products

“…In addition, a prevention of DNA damage, for example attenuated cyclobutane pyrimidine dimers formation, and prevention of cell apoptosis could be observed [31,38,39]. The pre-treatment of HaCaT keratinocytes with polyphenols or phenolic extracts leads to a decreased intracellular ROS formation, induced by UVB or hydrogen peroxide.…”

Chlorogenic acid prevents isoproterenol-induced DNA damage in vascular smooth muscle cells

“…Pang et al (31) revealed that CGA may prevent acetaminophen-induced liver oxidative stress injury via the regulation of cytochrome P450 metabolism enzymes and certain important anti-oxidant signal molecules, including proteins from the peroxiredoxins family. Cha et al (32) demonstrated that CGA reduced UVB-mediated oxidative stress in human HaCaT keratinocytes. The preventive effect of CGA with regards to VSMC damage and inhibition of Iso-induced DNA damage may have important implications in the clinical setting.…”