Anti-ageing effects of Sonchus oleraceus L. (pūhā) leaf extracts on H₂O₂-induced cell senescence.

Zong-Quan Ou,Arlene Mcdowell,Thomas Rades

doi:10.3390/molecules20034548

Zong-Quan Ou, Arlene Mcdowell + Show 1 more

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https://doi.org/10.3390/molecules20034548

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Abstract

Antioxidants protect against damage from free radicals and are believed to slow the ageing process. Previously, we have reported the high antioxidant activity of 70% methanolic Sonchus oleraceus L. (Asteraceae) leaf extracts. We hypothesize that S. oleraceus extracts protect cells against H2O2-induced senescence by mediating oxidative stress. Premature senescence of young WI-38 cells was induced by application of H2O2. Cells were treated with S. oleraceus extracts before or after H2O2 stress. The senescence- associated β-galactosidase (SA-β-gal) activity was used to indicate cell senescence. S. oleraceus extracts showed higher cellular antioxidant activity than chlorogenic acid in WI-38 cells. S. oleraceus extracts suppressed H2O2 stress-induced premature senescence in a concentration-dependent manner. At 5 and 20 mg/mL, S. oleraceus extracts showed better or equivalent effects of reducing stress-induced premature senescence than the corresponding ascorbic acid treatments. These findings indicate the potential of S. oleraceus extracts to be formulated as an anti-ageing agent.

Highlights

Ageing or senescence is a complex and inevitable biological process, which is attributed to individual genetic variation and to external factors such as environmental conditions, nutrition, alcohol and diseases [1,2,3,4]
We have previously shown that S. oleraceus leaf extracts are absorbed into cells in vitro and can exert an antioxidant effect, but it remains unclear if the antioxidants in S. oleraceus leaves are beneficial for cells in combating oxidative senescence
WI-38 cells retained greater than 90% viability after 3 h incubation with leaf extracts from S. oleraceus (Figure 1a)

Summary

Introduction

Ageing or senescence is a complex and inevitable biological process, which is attributed to individual genetic variation and to external factors such as environmental conditions, nutrition, alcohol and diseases [1,2,3,4]. There are three theories that have been proposed to explain ageing: genetic, neuroendocrine and damage-accumulation theories, which are all important and interrelated [5] Of these theories, the most widely accepted is the free radical theory that ageing and its related diseases result from accumulated oxidative damage to cell constituents and tissues caused by excessive exposure to free radicals [6]. Reactive species are generated during normal cell metabolism [7] or to protect humans from immediate death from infections [8] These reactive species can cause lipid peroxidation, denature proteins and fragment DNA due to oxidative stress, and further increase the mutation rate, especially when the antioxidant defenses cannot remove the excess free radicals [5,7,8]. Increasing oxidative stress is commonly associated with ageing and age-related diseases [9]

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