Protective effects and mechanisms of Terminalia catappa L. methenolic extract on hydrogen-peroxide-induced oxidative stress in human skin fibroblasts

Background

Oxidative stress plays a crucial role in aging-related phenomenon, including skin aging and photoaging. This study investigated the protective role and possible mechanism of Terminalia catappa L. methanolic extract (TCE) in human fibroblasts (Hs68) against hydrogen peroxide (H₂O₂)-induced oxidative damage.

Methods

Various in vitro antioxidant assays were performed in this study. The effect and mechanisms of TCE on oxidative stress-induced oxidative damage were studied by using western blotting.

Results

The IC₅₀ of TCE was 8.2 μg/mL for 1,1-diphenyl-2-picrylhydrazyl radical scavenging, 20.7 μg/mL for superoxide anion radical scavenging, 173.0 μg/mL for H₂O₂ scavenging, 44.8 μg/mL for hydroxyl radical scavenging, and 427.6 μg/mL for ferrous chelation activities. Moreover, TCE inhibited the H₂O₂-induced mitogen-activated protein kinase signaling pathway, resulting in the inhibition of c-Jun, c-Fos, matrix metalloproteinase (MMP)-1, MMP-3, MMP-9, and cyclooxygenase-2 expression. TCE also increased hemeoxygenase-1 expression inhibited by H₂O₂. Finally, TCE was demonstrated reverse type I procollagen expression in fibroblasts after H₂O₂ treatment.

Conclusions

According to our findings, TCE is a potent antioxidant and protective agent that can be used in antioxidative stress-induced skin aging.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2308-4) contains supplementary material, which is available to authorized users.

The therapeutic effect of fraxetin on ethanol-induced hepatic fibrosis by enhancing ethanol metabolism, inhibiting oxidative stress and modulating inflammatory mediators in rats

The present study was designed to investigate the possible protective effects of fraxetin against ethanol induced liver fibrosis in rats. Rats were underwent intragastric administration of ethanol (5.0-9.5 g/kg) once a day for 24 weeks. Effect of fraxetin against ethanol induced liver fibrosis was investigated by giving 20 or 50 mg/kg fraxetin. At the end of experiment, the livers were collected for histopathological analyses, protein extraction, and enzymatic activities. Our results indicated that fraxetin significantly corrected ethanol-induced hepatic fibrosis, as evidenced by the decrease in serum ALT and AST, the attenuation of histopathological changes. Fraxetin also expedited ethanol metabolism by enhancing the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities. Besides, fraxetin alleviated lipid peroxidation, enhanced hepatic antioxidant capabilities, inhibited CYP2E1 activity, and reduced the inflammatory mediators, including TNF-α and IL-1β via up-regulation of hemeoxygenase-1 (HO-1) protein. In summary, the hepatoprotection of fraxetin is mostly attributed to its antioxidant capability, alcohol metabolism, and anti-inflammation effect.