Anti-apoptotic effects of Curcuma longa L. extract and its curcuminoids against blue light-induced cytotoxicity in A2E-laden human retinal pigment epithelial cells.
OBJECTIVE
The purpose of the study was to investigate the protective effect of the Curcuma longa L. extract (CLE) and its curcuminoids against blue light-induced cytotoxicity in human retinal pigment epithelial (RPE) cells laded with A2E. A2E has been concerned in age-related macular degeneration (AMD).


METHODS
To perform this study, A2E-accumulated ARPE-19 cells were exposed to blue light to induce cytotoxicity. The cytotoxicity and apoptotic gene expression levels were evaluated using a lactate dehydrogenase (LDH) assay and real-time PCR analysis, respectively.


RESULTS
Curcuma longa L. extract was found to exert a protective effect in a dose-dependent manner. At a concentration of 15 μm, curcumin, demethoxycurcumin and bisdemethoxycurcumin exerted significant protective effects against blue light-induced cytotoxicity. Treatment with CLE and curcuminoids meaningfully reduced the mRNA levels of c-Abl and p53, which was known to be augmented in apoptotic RPE cells. Demethoxycurcumin and bisdemethoxycurcumin were found to inhibit p38 expression, which is increased in blue light-irradiated A2E-accumulated RPE cells.


CONCLUSIONS
Curcuma longa L. extract and its curcuminoids provided significant protection against photooxidative damage and apoptosis in the RPE cells. Our results suggest that curcuminoids may show potential in the treatment of AMD.
Department of Life and Nanopharmaceutical Sciences, Graduated School, Kyung Hee University, Seoul, Korea.
Sang-Il
SI
Park
Department of Life and Nanopharmaceutical Sciences, Graduated School, Kyung Hee University, Seoul, Korea.
Eun Hye
EH
Lee
Department of Optometry, Seoul National University of Science and Technology, Seoul, Korea.
So Ra
SR
Kim
Department of Life and Nanopharmaceutical Sciences, Graduated School, Kyung Hee University, Seoul, Korea.|Department of Oriental Pharmaceutical Sciences, College of Pharmacy, Kyung Hee University, Seoul, Korea.
Young Pyo
YP
Jang
D017209:Apoptosis / Q000187:drug effects*; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D030024:Curcuma / Q000737:chemistry*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008027:Light; D008268:Macular Degeneration / Q000188:drug therapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000187:drug effects* / Q000378:metabolism
D010936:Plant Extracts; D012333:RNA, Messenger

curcumin
; A2E; age-related macular degeneration; apoptosis; blue light