title: Beneficial effects of natural antioxidants EGCG and alpha-lipoic acid on life span and age-dependent behavioral declines in Caenorhabditis elegans.
abstract: Oxidative stress has been associated with both the aging process and the development of age-dependent tissue degenerative pathologies. Beneficial effects of antioxidant therapies to abrogate the deleterious consequences of elevated free radicals are implicated in disease prevention and cost-effective strategy. Previous data have shown protective effects of the polyphenol green tea constituent epigallocatechin gallate (EGCG) and a classic natural antioxidant alpha-lipoic acid (LA) against oxidative stress and aging. In this study, EGCG and alpha-lipoic acid were applied to model Caenorhabditis elegans, and their ability to modulate the life span and several age-associated behavioral declines were examined, including: pharyngeal pumping, chemotaxic behavior and amyloid beta-associated pathological behavior. It was demonstrated that both antioxidants attenuated the levels of hydrogen peroxide in C. elegans, but their effects on age-dependent decline in behaviors were different. EGCG, but not alpha-lipoic acid, attenuated the rate of decline in pharyngeal pumping behavior in C. elegans. In contrast, alpha-lipoic acid, but not EGCG, extended mean and maximal life span in C. elegans. Both EGCG and alpha-lipoic acid were able to facilitate the chemotaxis index and this effect was additive. Furthermore, EGCG, but not alpha-lipoic acid, moderately alleviated an Abeta-induced pathological behavior in a transgenic C. elegans strain. These results indicate that natural antioxidants can protect against age-dependent behavioral declines. Other protective mechanisms, in addition to their antioxidant properties, may underlie their differential beneficial effects on aging and physiological behaviors.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine St, PH501, Baltimore, MD 21201, USA.
authors.forename: Marishka K
authors.initials: MK
authors.lastname: Brown
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Evans
authors.forename: Yuan
authors.initials: Y
authors.lastname: Luo
mesh_terms: D000375:Aging / Q000523:psychology*; D016229:Amyloid beta-Peptides / Q000633:toxicity; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017173:Caenorhabditis elegans / Q000187:drug effects*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D008017:Life Expectancy; D010614:Pharynx / Q000502:physiology; D008063:Thioctic Acid / Q000494:pharmacology*
chemical_list: D016229:Amyloid beta-Peptides; D000975:Antioxidants; D008063:Thioctic Acid; D002392:Catechin; D006861:Hydrogen Peroxide; C045651:epigallocatechin gallate