Nrf2 Activation by SK-119 Attenuates Oxidative Stress, UVB, and LPS-Induced Damage

Skin Pharmacol Physiol. 2019;32(4):173-181. doi: 10.1159/000499432. Epub 2019 May 10.

Abstract

Background/aims: The Nrf2 signaling pathway plays a pivotal role in neutralizing excess reactive oxygen species formation and therefore enhancing the endogenous cellular protection mechanism. Thus, activating this pathway may provide therapeutic options against oxidative stress-related disorders. We have recently applied a computer-aided drug design approach to the design and synthesis of novel Nrf2 enhancers. The current study was aimed at investigating the potential beneficial impact of (E)-5-oxo-1-(4-((2,4,6-trihydroxybenzylidene)amino)phenyl)pyrrolidine-3-carboxylic acid (SK-119) in skin oxidative damage models.

Methods: SK-119, tested initially in PC-12 cells, attenuated oxidative stress-induced cytotoxicity concomitantly with Nrf2 activation. The potential impact of this compound was evaluated in skin-based disease models both in vitro (HaCaT cells) and ex vivo (human skin organ culture).

Results: The data clearly showed the marked anti-inflammatory and photoprotection properties of the compound; SK-119-treated cells or tissues displayed a reduction in cytokine secretion induced by lipopolysaccharides (LPS) in a manner comparable with dexamethasone. In addition, topical application of SK-119 was able to block UVB-induced oxidative stress and attenuated caspase-mediated apoptosis, DNA adduct formation, and the concomitant cellular damage.

Conclusion: These results indicate that SK-119 is an Nrf2 activator that can be used as a prototype molecule for the development of novel treatments of dermatological disorders related to oxidative stress.

Keywords: LPS-induced damage; Nrf2 activator; SK-119; UVB.

MeSH terms

  • Adult
  • Apoptosis
  • Benzylidene Compounds / pharmacology*
  • Caspase 3 / metabolism
  • Cells, Cultured
  • Cytokines / metabolism
  • DNA Damage / drug effects
  • Female
  • Humans
  • Lipopolysaccharides / pharmacology
  • Middle Aged
  • NF-E2-Related Factor 2 / metabolism*
  • Oxidative Stress / drug effects*
  • Pyrrolidines / pharmacology*
  • Signal Transduction / drug effects
  • Skin / drug effects*
  • Skin / metabolism
  • Ultraviolet Rays / adverse effects*

Substances

  • Benzylidene Compounds
  • Cytokines
  • Lipopolysaccharides
  • NF-E2-Related Factor 2
  • Pyrrolidines
  • Caspase 3