Astaxanthin protects mitochondrial redox state and functional integrity against oxidative stress.
Mitochondria combine the production of energy with an efficient chain of reduction-oxidation (redox) reactions but also with the unavoidable production of reactive oxygen species. Oxidative stress leading to mitochondrial dysfunction is a critical factor in many diseases, such as cancer and neurodegenerative and lifestyle-related diseases. Effective antioxidants thus offer great therapeutic and preventive promise. Investigating the efficacy of antioxidants, we found that a carotenoid, astaxanthin (AX), decreased physiologically occurring oxidative stress and protected cultured cells against strong oxidative stress induced with a respiratory inhibitor. Moreover, AX improved maintenance of a high mitochondrial membrane potential and stimulated respiration. Investigating how AX stimulates and interacts with mitochondria, a redox-sensitive fluorescent protein (roGFP1) was stably expressed in the cytosol and mitochondrial matrix to measure the redox state in the respective compartments. AX at nanomolar concentrations was effective in maintaining mitochondria in a reduced state. Additionally, AX improved the ability of mitochondria to remain in a reduced state under oxidative challenge. Taken together, these results suggest that AX is effective in improving mitochondrial function through retaining mitochondria in the reduced state.
Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Nippon Medical School, Nakahara-ku, Kawasaki, Kanagawa, Japan.
Alexander M
AM
Wolf
Sadamitsu
S
Asoh
Hidenori
H
Hiranuma
Ikuroh
I
Ohsawa
Kumiko
K
Iio
Akira
A
Satou
Masaharu
M
Ishikura
Shigeo
S
Ohta
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D045744:Cell Line, Tumor; D019069:Cell Respiration; D002470:Cell Survival; D019587:Dietary Supplements; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000473:pathology / Q000502:physiology*; D028361:Mitochondrial Diseases / Q000139:chemically induced / Q000178:diet therapy / Q000473:pathology / Q000517:prevention & control*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D024341:Xanthophylls / Q000008:administration & dosage
D000975:Antioxidants; D024341:Xanthophylls; D013481:Superoxides; D049452:Green Fluorescent Proteins; C005948:astaxanthine