Comparison of Antioxidant Properties of Dehydrolutein with Lutein and Zeaxanthin, and their Effects on Retinal Pigment Epithelial Cells

Dehydrolutein accumulates in substantial concentrations in the retina. The aim of this study was to compare antioxidant properties of dehydrolutein with other retinal carotenoids, lutein and zeaxanthin, and their effects on ARPE-19 cells. The time-resolved detection of characteristic singlet oxygen phosphorescence was used to compare the singlet oxygen quenching rate constants of dehydrolutein, lutein, and zeaxanthin. The effects of these carotenoids on photosensitized oxidation were tested in liposomes, where photooxidation was induced by light in the presence of photosensitizers, and monitored by oximetry. To compare the uptake of dehydrolutein, lutein, and zeaxanthin, ARPE-19 cells were incubated with carotenoids for up to 19 days, and carotenoid contents were determined by spectrophotometry in cell extracts. To investigate the effects of carotenoids on phototocytotoxicity, cells were exposed to light in the presence of rose bengal or all-trans-retinal. The results demonstrate that the rate constants for singlet oxygen quenching are 0.77x1010, 0.55x1010, and 1.23x1010 M-1s-1 for dehydrolutein, lutein and zeaxanthin, respectively. Overall, dehydrolutein is similar to lutein or zeaxanthin in protection of lipids against photosensitized oxidation. ARPE-19 cells accumulate substantial amounts of both zeaxanthin and lutein but no detectable amounts of dehydrolutein. Cells pre-incubated with carotenoids are equally susceptible to photosensitized damage as cells without carotenoids. Carotenoids provided to cells together with the extracellular photosensitizers offer partial protection against photodamage. In conclusion, the antioxidant properties of dehydrolutein are similar to lutein and zeaxanthin. The mechanism responsible for its lack of accumulation in ARPE-19 cells deserves further investigation.

Download Full-text

Comparison of Antioxidant Properties of Dehydrolutein with Lutein and Zeaxanthin, and their Effects on Cultured Retinal Pigment Epithelial Cells

Antioxidants ◽

10.3390/antiox10050753 ◽

2021 ◽

Vol 10 (5) ◽

pp. 753

Author(s):

Małgorzata B. Różanowska ◽

Barbara Czuba-Pelech ◽

John T. Landrum ◽

Bartosz Różanowski

Keyword(s):

Singlet Oxygen ◽

Rate Constants ◽

Retinal Pigment ◽

Antioxidant Properties ◽

Retinal Pigment Epithelial Cells ◽

Oxygen Quenching ◽

Quenching Rate ◽

Photosensitized Oxidation ◽

Singlet Oxygen Quenching ◽

Cell Extracts

Dehydrolutein accumulates in substantial concentrations in the retina. The aim of this study was to compare antioxidant properties of dehydrolutein with other retinal carotenoids, lutein, and zeaxanthin, and their effects on ARPE-19 cells. The time-resolved detection of characteristic singlet oxygen phosphorescence was used to compare the singlet oxygen quenching rate constants of dehydrolutein, lutein, and zeaxanthin. The effects of these carotenoids on photosensitized oxidation were tested in liposomes, where photo-oxidation was induced by light in the presence of photosensitizers, and monitored by oximetry. To compare the uptake of dehydrolutein, lutein, and zeaxanthin, ARPE-19 cells were incubated with carotenoids for up to 19 days, and carotenoid contents were determined by spectrophotometry in cell extracts. To investigate the effects of carotenoids on photocytotoxicity, cells were exposed to light in the presence of rose bengal or all-trans-retinal. The results demonstrate that the rate constants for singlet oxygen quenching are 0.77 × 1010, 0.55 × 1010, and 1.23 × 1010 M−1s−1 for dehydrolutein, lutein, and zeaxanthin, respectively. Overall, dehydrolutein is similar to lutein or zeaxanthin in the protection of lipids against photosensitized oxidation. ARPE-19 cells accumulate substantial amounts of both zeaxanthin and lutein, but no detectable amounts of dehydrolutein. Cells pre-incubated with carotenoids are equally susceptible to photosensitized damage as cells without carotenoids. Carotenoids provided to cells together with the extracellular photosensitizers offer partial protection against photodamage. In conclusion, the antioxidant properties of dehydrolutein are similar to lutein and zeaxanthin. The mechanism responsible for its lack of accumulation in ARPE-19 cells deserves further investigation.

Download Full-text

Triplet energies, singlet state properties and singlet oxygen quenching rate constants and quantum yields for two cyan azamethine dyes

Journal of Photochemistry and Photobiology A Chemistry ◽

10.1016/s1010-6030(98)00398-0 ◽

1999 ◽

Vol 120 (1) ◽

pp. 29-36 ◽

Cited By ~ 4

Author(s):

Richard J. Berry ◽

Peter Douglas ◽

Michael S. Garley ◽

Tony Jolly ◽

Dave Clarke ◽

...

Keyword(s):

Singlet Oxygen ◽

Rate Constants ◽

Singlet State ◽

Quantum Yields ◽

Oxygen Quenching ◽

Quenching Rate ◽

Singlet Oxygen Quenching

Download Full-text

Carotenoids, tocopherols and thiols as biological singlet molecular oxygen quenchers

Biochemical Society Transactions ◽

10.1042/bst0181054 ◽

1990 ◽

Vol 18 (6) ◽

pp. 1054-1056 ◽

Cited By ~ 182

Author(s):

PAOLO Di MASCIO ◽

THOMAS P. A. DEVASAGAYAM ◽

STEPHAN KAISER ◽

HELMUT SIES

Keyword(s):

Singlet Oxygen ◽

Molecular Oxygen ◽

Rate Constants ◽

Protective Action ◽

Biological Tissues ◽

Oxygen Quenching ◽

Quenching Rate ◽

Singlet Molecular Oxygen ◽

Singlet Oxygen Quenching ◽

Β Carotene

Singlet molecular oxygen (1O2) has been shown to be generated in biological systems and is capable of damaging proteins, lipids and DNA. The ability of some biological antioxidants to quench 1O2 was studied by using singlet oxygen generated by the thermodissociation of the endoperoxide of 3,3′-(1,4-naphthylidene) dipropionate (NDPO2). The carotenoid lycopene was the most efficient 1O2 quencher (kq + kr = 31 × 109m-1s-1). Tocopherols and thiols were less effective. The singlet oxygen quenching ability decreased in the following order: lycopene, γ-carotene, astaxanthin, canthaxanthin, α-carotene, β-carotene, bixin, zeaxanthin, lutein, bilirubin, biliverdin, tocopherols and thiols. However, the compounds with low quenching rate constants occur at higher levels in biological tissues. Thus, carotenoids and tocopherols may contribute almost equally to the protection of tissues against the deleterious effects of 1O2. The quenching abilities of carotenoids and tocopherols were mainly due to physical quenching. In case of some thiols chemical quenching also plays a significant role. Carotenoids and tocopherols have been reported to exert a protective action against some types of cancer.

Download Full-text