Background and Objectives: Chamaecyparis obtusa (C. obtuse) extract has been used as a folk medicinal remedy in East Asian countries to alleviate inflammation and prevent allergies. Active oxygen causes skin aging and leads to skin cell and tissue damage. Extensive research has been conducted to control active oxygen generation to prevent skin aging. We evaluated the antioxidant activity and antiwrinkle effect of C. obtusa extract to determine its potential as a cosmetic material. Materials and Methods: The antioxidant activity of a 70% ethanol extract of C. obtusa (COE 70) and a water extract of C. obtusa (COW) was determined using 2,2-diphenyl-1-picrylhydrazy (DPPH) scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) scavenging, superoxide dismutase-like activity, xanthine oxidase inhibition, and ferric-reducing antioxidant power assays. The effective concentration of the extracts was determined using the methyl thiazolyl tetrazolium assay to evaluate their toxicity. The effects of COE 70 on the production of matrix metalloproteinases (MMPs) and procollagen, and expression of activated cytokines, interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), in UVA-irradiated fibroblasts were determined using quantitative real-time PCR. Additionally, quercitrin, amentoflavone, hinokiflavone, and myricetin concentrations in COE 70 were determined using high-pressure high-performance liquid chromatography. Results: COE 70 had higher polyphenol and flavonoid concentrations than COW and exhibited an excellent antioxidant effect. COE 70 suppressed UVA-induced fibroblast death by 21.3% at 25 µg/mL. It also increased MMP-1, MMP-3, TNF-α, and IL-6 mRNA levels at 5-25 µg/mL compared with those in control UVA-irradiated fibroblasts. Moreover, mRNA levels of collagen type I and superoxide dismutase significantly increased, indicating the antiwrinkle and anti-inflammatory effects of the extract. Among the COE 70 components, quercitrin concentration was the highest; hence, quercitrin could be an active ingredient. Conclusions: COE 70 could be used as a natural antioxidant and antiwrinkle agent.
Keywords: Chamaecyparis obtusa; antioxidant; antiwrinkle; fibroblast; flavonoid; quercitrin.