Protective Effect of Castanopsis sieboldii Extract against UVB-Induced Photodamage in Keratinocytes

Abstract

Ultraviolet B (UVB) rays disrupt the skin by causing photodamage via processes such as reactive oxygen species (ROS) production, endoplasmic reticulum (ER) stress, DNA damage, and/or collagen degradation. Castanopsis sieboldii is an evergreen tree native to the southern Korean peninsula. Although it is known to have antioxidant and anti-inflammatory effects, its protective effect against photodamage in keratinocytes has not been investigated. Thus, in the present study, we investigated the effect of 70% ethanol extract of C. sieboldii leaf (CSL3) on UVB-mediated skin injuries and elucidated the underlying molecular mechanisms. CSL3 treatment restored the cell viability decreased by UVB irradiation. Moreover, CSL3 significantly inhibited UVB- or tert-butyl hydroperoxide-mediated ROS generation in HaCaT cells. ER stress was inhibited, whereas autophagy was upregulated by CSL3 treatment against UVB irradiation. Additionally, CSL3 increased collagen accumulation and cell migration, which were decreased by UVB exposure. Notably, epigallocatechin gallate, the major component of CSL3, improved the cell viability decreased by UVB irradiation through regulation of ER stress and autophagy. Conclusively, CSL3 may represent a promising therapeutic candidate for the treatment of UVB-induced skin damage.

Castanopsis sieboldii Extract Alleviates Acute Liver Injury by Antagonizing Inflammasome-Mediated Pyroptosis

“…indicate that CSL3 treatment restored CCl4-induced liver inflammation and injury by inhibiting inflammasome-mediated pyroptosis. We found that CSL3 contained the highest content of phenolic compounds, and the major constituent of CSL3 was epigallocatechin-3-gallate (EGCG), a well-known antioxidant and anti-inflammatory polyphenol, by HPLC and LC-MS/MS analysis [12]. Surprisingly, the EGCG content in CS was much higher than in green tea.…”

“…In addition, it was reported that the leaf extract of CS (CSL) had high antioxidant and antibacterial activities. Previously, we succeeded in extracting CS under several conditions and found that the 70% EtOH extract of CSL (CSL3) had the highest antioxidant activity [12]. Moreover, we found that CSL3 protected against reactive oxygen species (ROS) production and cell death in UVB-irradiated keratinocytes by inhibiting ER stress and activating autophagy.…”

“…Biochemical and genetic experimental models were still required to unveil the concise molecular mechanism of CSL3. (3) It was reported that EGCG, a major We found that CSL3 contained the highest content of phenolic compounds, and the major constituent of CSL3 was epigallocatechin-3-gallate (EGCG), a well-known antioxidant and anti-inflammatory polyphenol, by HPLC and LC-MS/MS analysis [12]. Surprisingly, the EGCG content in CS was much higher than in green tea.…”

“…In addition, the leaf extract of CS has high antioxidant and antibacterial activities [11]. Recently, we determined that the 70% ethanol (EtOH) extract of the CS leaf (CSL3) has cytoprotective and antioxidant effects in keratinocytes against UV-irradiated photodamage [12]. However, the effects of CSL3 on acute hepatitis and Kupffer cell activation remain unknown.…”

Endoplasmic reticulum stress in skin aging induced by UVB

“…43 Castanopsis sieboldii extract itself can reduce ROS production and relieve ER stress, but the specific mechanism needs further study. 44…”