The purpose of this study is to investigate whether topically applied constituents of green tea \[caffeine or (-)-epigallocatechin gallate; EGCG\] have a protective effect on skin exposed to ultraviolet light (UV).
The purpose of this study is to investigate if topically applied constituents of green tea \[caffeine or (-) - epigallocatechin gallate; EGCG\] have a protective effect on skin exposed to ultraviolet light (UV). In the double-blinded study all subjects will receive 311 nanometer UVB light at a dose that is 0.5-1.5X their individual minimal erythema dose (MED). One part of the experiment will involve applying a topical natural product (caffeine or EGCG) and placebo to bilateral symmetric sites. The natural product and the placebo will be applied immediately after and at 1/2 hour, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 24 hours, 25 hours, and 27 hours after exposure to a 0.5-1.5 MED dose of UV light. Another part of the study involves performing skin biopsies. One will be done prior to UVB exposure, 2 will be done at 24 hours and 2 more will be done at 48 hours.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
68
Green tea product (EGCG or caffeine) in vehicle will be applied immediately after and at sequential time points after exposure of a 5x5-cm area of skin to a dose of UVB that is 0.5-2 times the subject's minimal erythema dose (MED)
Placebo (vehicle alone) will be applied immediately after and at sequential time points after exposure of a 5x5-cm area of skin to a dose of UVB that is 0.5-2 times the subject's minimal erythema dose (MED)
UMDNJ Division of Clinical Pharmacology
New Brunswick, New Jersey, United States
Change in UVB-Induced Active Caspase-3-Positive Keratinocytes by Green Tea Compounds
The mean change in number of active caspase-3+ apoptotic keratinocytes between 0- and 48-hour time points was calculated for skin biopsy samples of subjects who had been exposed to UVB on symmetrical right and left test sites which were then randomized to receive active test substance (EGCG or caffeine) or placebo (vehicle) at sequential time points after UVB exposure.
Time frame: 48 hrs
Change in UVB-Induced Apoptotic "Sunburn" Cells by Green Tea Compounds
The mean change in number of apoptotic "sunburn" cells between 0- and 48-hour time points was calculated for skin biopsy samples of subjects who had been exposed to UVB on symmetrical right and left test sites which were then randomized to receive active test substance (EGCG or caffeine) or placebo (vehicle) at sequential time points after UVB exposure.
Time frame: 48 hr
Effect of Topical Applications of 4-6% Caffeine on UVB-Induced Increases in Apoptotic "Sunburn" Cells
The percentage of apoptotic "sunburn" cells was identified in the 48-hr time point skin biopsy samples of subjects who had been exposed to UVB on symmetrical right and left test sites which were then randomized to receive 4-6% caffeine in cream vehicle or placebo (cream vehicle) at sequential time points after UVB exposure.
Time frame: 48 hr
Effect of Topical Applications of 4-6% Caffeine on UVB-Induced Increases in Caspase-3-Positive Cells
The percentage of caspase-3-positive cells was identified in the 48-hr time point skin biopsy samples of subjects who had been exposed to UVB on symmetrical right and left test sites which were then randomized to receive 4-6% caffeine in cream vehicle or placebo (cream vehicle) at sequential time points after UVB exposure.
Time frame: 48 hr
Effect of Topical Applications of 4-6% Caffeine on UVB-Induced Increases in Phospho-p53 (Ser15) Positive Cells
The percentage of phospho-p53 (Ser15) positive cells was identified in the 48-hr time point skin biopsy samples of subjects who had been exposed to UVB on symmetrical right and left test sites which were then randomized to receive 4-6% caffeine in cream vehicle or placebo (cream vehicle) at sequential time points after UVB exposure.
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Time frame: 48 hr
Effect of Green Tea Compounds on UVB-Induced Erythema
Erythema of the right and left test sites was scored on a scale of 0-3 (0 = no evidence \[no erythema\]; 1 = mild \[pink or light red color\]; 2 = moderate \[red color\]; 3 = severe \[very red or dark color\]) including half-integer grading. Scoring was performed immediately after UVB exposure and at sequential time points thereafter. The mean scores at 48 hr were calculated.
Time frame: 48 hrs
Effect of 4-6% Caffeine on UVB-Induced Erythema
Erythema of the right and left test sites was scored on a scale of 0-3 (0 = no evidence \[no erythema\]; 1 = mild \[pink or light red color\]; 2 = moderate \[red color\]; 3 = severe \[very red or dark color\]) including half-integer grading. Scoring was performed immediately after UVB exposure and at sequential time points thereafter. The erythema scores at 6, 8, and 24 hr post-UVB were averaged.
Time frame: 24 hr