Title:Silymarin Extends Lifespan and Reduces Proteotoxicity in C. elegans Alzheimer’s Model
VOLUME: 14 ISSUE: 2
Author(s):Jitendra Kumar, Kyung-Chae Park, Anjali Awasthi and Birendra Prasad
Affiliation:Buck Institute for Aging Research, 8001 Redwood Blvd., Novato, CA 94945, USA.
Keywords:Aging, Alzheimer‘s disease (AD), Caenorhabditis elegans, lifespan, oxidative stress, silymarin.
Abstract:Aging is a process of progressive decline in physiological functions resulting in increased
vulnerability to diseases and death. Aging results in increased rates of age related disorders like
neurodegenerative diseases, cardiovascular diseases, diabetes, cancer, arthritis etc. Modulation of
insulin signaling, protein aggregation, stress, free radical damage and inflammation are the major
causes for deleterious changes resulting in aging. Many studies are being undertaken to find novel
compounds which can improve a typical human life span and aid in healthy aging. We investigated
the potential of one such compound silymarin for its anti-aging effect. Silymarin is a flavanone
derivative extracted from the seeds of the milk thistle Silybum marianum. It is widely used for the
treatment of liver diseases in clinical practice. We tested the anti-aging efficacy of silymarin using
the Caenorhabditis elegans model system. Our results demonstrate that C. elegans treated with
25μM and 50μM silymarin concentration resulted in an increase in mean lifespan by 10.1% and 24.8% respectively
compared to untreated control. Besides increased lifespan, silymarin treated aged animals showed better locomotion rate,
higher response to stimuli and improved tolerance to stress compared to untreated control. We also checked the potential
of silymarin to slow the progression of neurodegenerative disorder like Alzheimer's disease (AD) by using CL4176 C.
elegans model for AD. C. elegans CL4176 transgenic animal induces expression of amyloid beta-protein (Aβ1-42) in
muscle tissues when subjected to temperature of 23°C and above resulting in worm paralysis. CL4176 animals treated
with silymarin showed delayed paralysis via enhancing resistance to oxidative stress. These results suggested that
silymarin is a potential hormetin for preventing aging and age-related diseases.
