Detrimental Effects of UVB on Retinal Pigment Epithelial Cells and Its Role in Age-Related Macular Degeneration

Table 2

The photoprotective effect of bioactive compounds or extracts obtained from natural products against UVB-induced damage on RPE cells.

Bioactive compounds or extracts of natural product	Source of natural product	Concentration, type, and duration of treatment	UV range and dosage	Subject of study	Photoprotective effect on RPE	Citations
Lutein	Silkworm (Bombyx mori), marigold, vegetable, and fruits	(1) First study: (i) Concentration of 50 μM or 25 μM in combination with trolox,; (ii) 4 h pretreatment before irradiation; (2) Second study: (i) Concentration of 5 μM, 1 h pretreatment before irradiation	(1) First study: (i) UVB (40 mJ/cm^2); (2) Second study: (i) UVB (50 mJ/cm^2)	ARPE-19 cell line	(1) First study: (a) Increase cell viability; (b) Decrease lipid peroxidation; (c) Decrease ROS and caspase-3 protein levels; (d) Decrease glutathione peroxidase activity; (e) Modulate catalase activity opposing to UVB-induced changes; (2) Second study: (a) Increase cell viability; (b) Decrease ROS; (c) Decrease phosphorylation of JNK1/2 and p38	[52, 108, 153]
Zeaxanthin	Fruits and vegetables	(1) First study: (i) Concentration of 50 μM or 25 μM in combination with trolox, 4 h pretreatment before irradiation; (2) Second study: (i) Concentration of 5 μM, 1 h pretreatment before irradiation	(1) First study: (i) UVB (40 mJ/cm^2); (2) Second study: (i) UVB (50 mJ/cm^2)	ARPE-19 cell line	(1) First study: (a) Increase cell viability; (b) Decrease lipid peroxidation; (c) Decrease ROS and caspase-3 protein levels; (d) Decrease glutathione peroxidase activity; (e) Modulate catalase activity opposing to UVB-induced changes; (2) Second study: (a) Increase cell viability; (b) Decrease ROS; (c) Decrease phosphorylation of JNK1/2 and p38	[52, 108, 153]
EGCG	Green tea	(1) First study: (i) Concentration of 5 μM, 2 h pretreatment before irradiation; (2) Second study: (i) Concentration of 50 μM, 3 h pretreatment before irradiation	(1) First study: (i) UVB (50 mJ/cm^2); (2) Second study: (i) UVB (100 mJ/cm^2)	ARPE-19 cell line	(1) First study: (a) Decrease cell apoptosis; (b) Decrease ROS; (c) Increase JNK and c-Jun phosphorylation; (2) Second study: (a) Increase cell viability; (b) Decrease in LC3-II proteins expression level; (c) Increase phosphorylation of S6K and 4E-BP1	[51, 127]
Cyanidin-3-glucosidase	Fruits and vegetables	Concentration of 5 μM, 1 h pretreatment before irradiation	UVB (50 mJ/cm^2)	ARPE-19 cell line	(a) Increase cell viability; (b) Decrease ROS; (c) Decrease phosphorylation of JNK1/2 and p38	[108, 157]
Tannic acid	Tea, coffee beans	Concentration of 25 μM, 1 h pretreatment before irradiation	UVB (10 mJ/cm^2)	ARPE-19 cell line	(a) Decreases IL-6 protein expression levels; (b) Decrease STAT3 phosphorylation on Tyr705; (c) Decrease CFB mRNA expression levels	[101, 158]
Lycium barbarum ethanolic and aqueous extract	Lycium barbarum	Concentration of 25 μM and 50 μM, 2 h pretreatment before irradiation	UVB (50 mJ/cm^2)	ARPE-19 cell line	(a) Increase cell viability; (b) Decrease ROS; (c) Decrease cell apoptosis and DNA damage; (d) Prevent the loss of mitochondrial membrane potential	[103]
Green tea polyphenols	Green tea	(1) First study: (i) Concentration of 70 and 140 mg/L, 2 h pretreatment before irradiation and 2 h posttreatment after irradiation; (2) Second study: (i) Concentration of 70 and 140 mg/L, 2 h pretreatment before irradiation and 2 h posttreatment after irradiation	(1) First study: (i) UVB (720 mJ/cm^2); (2) Second study: (i) UVB (720 mJ/cm^2)	(1) First study: (i) D407; (2) Second study: (i) D407	(1) First study: (a) Increase cell viability; (b) Decrease DNA fragmentation; (c) Increase expression of survivin gene; (2) Second study: (a) Decrease c-Fos mRNA and protein levels	[104, 111]