Abstract
Ultraviolet (UV) irradiation generates reactive oxygen species (ROS) in the cells, which induces the cellular senescence and photoaging. The present study investigated the protective effects of garlic on photo-damage and cellular senescence in UVB-exposed human keratinocytes, HaCaT cells. An in vitro cell free system was used to examine the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and nitric oxide (NO). The effect of garlic extract on ROS formation, MMP-1 protein and mRNA expressions, cytokines such as interleukin (IL)-1β and IL-6, senescence associated-β-galactosidase (SA-β-gal) activity, and silent information regulator T1 (SIRT1) activity were determined in UVB-irradiated HaCaT cells. Garlic exhibited strong DPPH radical and NO scavenging activity in cell free system exhibiting IC50 values of 2.50 mg/mL and 4.38 mg/mL, respectively. Garlic pretreatment attenuated the production of UVB-induced intracellular ROS. MMP-1 level, which has been known to be induced by ROS, was dramatically elevated by UVB irradiation, and UVB-induced MMP-1 mRNA and protein expressions were significantly reduced by garlic treatment (50 µg/mL) comparable to those of UV-unexposed control cells. UV-induced pro-inflammatory cytokine productions (IL-6 and IL-1β) were significantly inhibited by pretreatment with garlic in a dose-dependent manner. SA-β-gal activity, a classical biomarker of cellular senescence, and SIRT1 activity, which has attracted attention as an anti-aging factor in recent years, were ameliorated by garlic treatment in UV-irradiated HaCaT cells. The present study provides the first evidence of garlic inhibiting UVB-induced photoaging as a result of augmentation of cellular senescence in HaCaT human keratinocytes.
Highlights
Aging is due to an accumulation of detrimental changes overtime at both the molecular and cellular levels, which leads to a functional decline at the tissue and organ level
MMP-1 level, which has been known to be induced by reactive oxygen species (ROS), was dramatically elevated by UVB irradiation, and UVB-induced MMP-1 mRNA and protein expressions were significantly reduced by garlic treatment (50 μg/mL) comparable to those of UV-unexposed control cells
The present study provides the first evidence of garlic inhibiting UVB-induced photoaging as a result of augmentation of cellular senescence in HaCaT human keratinocytes
Summary
Aging is due to an accumulation of detrimental changes overtime at both the molecular and cellular levels, which leads to a functional decline at the tissue and organ level. The etiology of aging has not been fully understood, several cellular and molecular hallmarks may contribute to this process. Cellular senescence can be induced by telomere shortening, activation of tumor suppressor genes and oncogenes, chronic inflammation, oxidative stress, and ultraviolet (UV) irradiation [1,2]. Oxidative stress and chronic inflammatory process are major risk factors underlying aging and age-related diseases [3,6]. UV irradiation is the most common environmental factor that damages the human skin, leading to conditions such as skin carcinogenesis, inflammation, solar erythema and premature senescence [7].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
