Eucalyptus globulus extract protects against UVB-induced photoaging by enhancing collagen synthesis via regulation of TGF-β/Smad signals and attenuation of AP-1

Arch Biochem Biophys. 2018 Jan 1:637:31-39. doi: 10.1016/j.abb.2017.11.007. Epub 2017 Nov 24.

Abstract

UV irradiation triggers the overproduction of matrix metalloproteinases and collagen degradation, which in turn causes increased pigmentation, dryness, and deep wrinkling of the skin. These chronic symptoms are collectively referred to as photoaging. Eucalyptus globulus is an evergreen tree that is widely used in cosmetics because of its antimicrobial activity. In this study, we investigated the protective effect of 50% ethanol extracts of Eucalyptus globulus on UV-induced photoaging in vitro and in vivo. Normal human dermal fibroblasts were treated with Eucalyptus globulus at concentrations ranging from 1 to 100 μg/mL after UVB or non-UVB irradiation. We found that Eucalyptus globulus suppressed the expression of MMPs and IL-6, but increased the expression of TGF-β1 and procollagen type 1. In addition, Eucalyptus globulus inhibited activation of the AP-1 transcription factor, an inducer of MMPs. Eucalyptus globulus was also found to regulate TGF-β/Smad signaling by reversing the activity of negative Smad regulators. Lastly, in vivo studies showed that topical application of Eucalyptus globulus on UVB-irradiated hairless mice reduced wrinkle formation and dryness by down-regulating MMP-1 and up-regulating expression of elastin, TGF-β1, and procollagen type 1. Taken together, these data suggest that Eucalyptus globulus may be a useful agent in cosmetic products.

Keywords: Eucalyptus globulus; Hairless mice; MMP-1; Photoaging; Procollagen type 1; TGF-β1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Collagen Type I / biosynthesis*
  • Collagen Type I / genetics
  • Eucalyptus*
  • Female
  • Humans
  • In Vitro Techniques
  • Matrix Metalloproteinase 1 / genetics
  • Mice
  • Mice, Hairless
  • Plant Extracts / pharmacology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Signal Transduction / drug effects
  • Skin / drug effects
  • Skin / metabolism
  • Skin / radiation effects
  • Skin Aging / drug effects*
  • Skin Aging / physiology
  • Smad Proteins / metabolism*
  • Transcription Factor AP-1 / metabolism*
  • Transforming Growth Factor beta / metabolism*
  • Ultraviolet Rays / adverse effects

Substances

  • Collagen Type I
  • Plant Extracts
  • RNA, Messenger
  • Smad Proteins
  • Transcription Factor AP-1
  • Transforming Growth Factor beta
  • MMP1 protein, human
  • Matrix Metalloproteinase 1