Protective effects of ellagic and chlorogenic acids against oxidative stress in PC12 cells

Abstract

Following exposure of differentiated neuronal PC12 cells to either t-BHP, hydrogen peroxide (H₂O₂) or FeSO₄ various kinds of reactive oxygen species (ROS) are generated leading to oxidative injury. The protective effects of two plant polyphenols, ellagic (EC) and chlorogenic acid (CGA), as well as of two metabolites, caffeic acid (CA) and ferulic acid (FA), were investigated in preincubation and coincubation experiments with respect to the following parameters: prevention of cell death, GSH depletion, lipid peroxidation and ROS formation.

The polyphenols more efficiently suppressed cytotoxicity and loss of GSH caused by peroxides than by iron, particularly in preincubation. Lipid peroxidation which increased much stronger in response to FeSO₄ was counteracted completely by the polyphenols. In case of iron, however, only coincubation was effective. EA and CGA and the metabolites CA and FA showed excellent elimination of ROS induced by all stressors. These findings suggest that two dietary antioxidants, EA and CGA, may have protective properties against oxidative stress induced in CNS.

• Polyphenols
• ROS
• oxidative stress
• antioxidants
• iron chelation
• PC12 cells

Abbreviations
CGA	=	chlorogenic acid
EA	=	ellagic acid
ROS	=	reactive oxygen species
H2O2	=	hydrogen peroxide
t-BHP	=	tert-butyl hydroperoxide
MTT	=	3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromid
GSH	=	glutathione
MDA	=	malondialdehyde
DCF	=	2′7′-dichlorofluorescein

Abbreviations
CGA	=	chlorogenic acid
EA	=	ellagic acid
ROS	=	reactive oxygen species
H2O2	=	hydrogen peroxide
t-BHP	=	tert-butyl hydroperoxide
MTT	=	3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromid
GSH	=	glutathione
MDA	=	malondialdehyde
DCF	=	2′7′-dichlorofluorescein