Development of a whole-organism model to screen new compounds for sun protection.
We used zebrafish as a whole-organism model to screen new compounds for sun protection activity. First of all, we designed a series of UVB exposure experiments and recorded the phenotypic changes of zebrafish embryos. Results showed that 100 mJ/cm(2) of UVB given six times separated by 30 min intervals is the best condition. Fin malformation (reduced and/or absent fin) phenotypes are the most evident consequences after exposure to UVB. Each fin was affected by UVB, including pelvic, ventral, caudal, and dorsal fin, but pelvic fin seemed to be the most sensitive target after UVB exposure. We furthermore carried out "prevention" and "treatment" experiments using green tea extract and/or (-)-epigallocatechin (EGCG) to test this whole-organism model by observing the morphological changes of all fins (especially pelvic fin) after UVB exposure. Effects of UVB, green tea extract and EGCG on fin development were assessed using the Kaplan-Meier analysis, log-rank test and Cox proportional hazards regression. Results showed that a zebrafish pelvic fin in the UVB + green tea (treatment) group is 5.51 (range from 2.39 to 14.90) times, one in the UVB + green tea (prevention) group is 7.04 (range from 3.11 to 18.92) times, and one in the 25 ppm of EGCG (prevention) group is 22.19 (range from 9.40 to 61.50) times more likely to return to normal fin than one in the UVB only group. On the basis of these observations, we believe this model is effective for screening the higher stability and lower toxicity of new compounds, such as small chemicals which are derivative from EGCG or other dietary agents for sun protection.
Wang
Yun-Hsin
YH
Department of Research, Sun Yat-Sen Cancer Center, Taipei, Taiwan.
Wen
Chi-Chung
CC
Yang
Zhi-Shiang
ZS
Cheng
Chien-Chung
CC
Tsai
Jen-Ning
JN
Ku
Chia-Chen
CC
Wu
Hsin-Ju
HJ
Chen
Yau-Hung
YH
D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D028241:Camellia sinensis; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D005121:Extremities / Q000528:radiation effects*; D020287:In Situ Nick-End Labeling; D023421:Models, Animal; D010936:Plant Extracts / Q000494:pharmacology; D012044:Regression Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013473:Sunscreening Agents / Q000592:standards*; D014466:Ultraviolet Rays / Q000009:adverse effects; D015027:Zebrafish
D017931:DNA Primers; D010936:Plant Extracts; D013473:Sunscreening Agents; C465546:green tea extract AR25; D002392:Catechin; C057580:gallocatechol