Silymarin extends lifespan and reduces proteotoxicity in C. elegans Alzheimer's model

CNS Neurol Disord Drug Targets. 2015;14(2):295-302. doi: 10.2174/1871527314666150116110212.


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.

MeSH terms

  • Alzheimer Disease / complications
  • Alzheimer Disease / drug therapy*
  • Alzheimer Disease / genetics*
  • Amyloid beta-Peptides / genetics*
  • Analysis of Variance
  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Humans
  • Longevity / drug effects*
  • Movement / drug effects
  • Paralysis / drug therapy
  • Paralysis / genetics
  • Peptide Fragments / genetics*
  • Protective Agents / therapeutic use*
  • Silymarin / therapeutic use*
  • Survival Analysis


  • Amyloid beta-Peptides
  • Peptide Fragments
  • Protective Agents
  • Silymarin
  • amyloid beta-protein (1-42)