The Effects of Coenzyme Q10, Kinetin, and Thioctic acid on Ultraviolet B Irradiated Cultured Human Skin Fibroblasts

Park, Seok Yeol; Mun, Kyo Cheol; Kim, Byung Chun; Lee, Kyu Suk

Abstract

BACKGROUND
Coenzyme Q10 is an endogenous lipid soluble antioxidant that scavenges reactive oxygen species (ROS) directly, inhibits biomolecule oxidation, and affects antioxidant defense in vivo. Kinetin (N6-furfuryladenine) belongs to the family of N6-substituted adenine derivatives known as cytokinins. Kinetin also exerts anti-aging effects. Commercial products of coenzyme Q10 and kinetin are developed and are selling as a rejuvenating drug. However, the action mechanisms of kinetin are not fully known, though it has been suggested to act both as an inhibitor of reactive oxygen species (ROS) formation and as a scavenger of ROS. Thioctic acid (alpha-Lipoic acid), which becomes a powerful antioxidant in its reduced form, has been suggested as a dietary supplement to treat diseases associated with excessive oxidant stress. Exposure of the skin to ultraviolet (UV) radiation, particulary UVB (290-320nm), causes adverse biological effects, including alterations in cutaneous immune cells, photoaging and photocarcinogenesis. Several studies have shown that coenzyme Q10, kinetin, and thioctic acid afforded the protection effects against UVB-induced inflammatory responses and photoaging.
Objective
and Method: In this study, we investigated the effects of coenzyme Q10, kinetin and thioctic acid on UVB irradiated human skin fibroblasts using a viability test, thiobarbituric acid assay and Northern blot analysis. RESULT: Cell survival curves after UVB irradiation showed a dose dependent decremental pattern by trypan blue exclusion assay. Only 30% of dermal fibroblasts survived at 150mJ/cm2 UVB irradiation. The damage was associated with cell membrane lipid peroxidation, as shown by accumulation malondialdehyde (MDA). By pre-cultivation with coenzyme Q10, kinetin and thioctic acid, a significant protection effect was noted as an increase in the absolute number of surviving cells and marked decrease in the levels of MDA. CONCLUSION: Coenzyme Q10, kinetin, and thioctic acid, which have been newly accepted as having UV protection properties, are effective membrane peroxidation inhibitors and inhibitors of reactive oxygen species (ROS) formation and scavenger of ROS.