Protective effect of 4-coumaric acid from UVB ray damage in the rabbit eye.
UV-induced oxidation damage seems to play a major role in a number of specific pathological conditions of intraocular tissues, such as cataract formation and retinal degeneration. Therefore, antioxidant and/or scavenger compounds might protect the eyes from UV-induced cellular damage. We previously reported that 4-coumaric acid (4-CA) is able to protect rabbit corneal-derived cells (SIRC) from UVB-induced oxidation damage. In this study we evaluated the protective effect of 4-CA against UVB-induced cell damage in rabbit cornea in vivo. Twelve male New Zealand albino rabbits were used; four rabbits were used as a control and received vehicle in one eye and 4-CA acid in the contralateral eye; eight rabbits were exposed to UVB rays (79.2mJ/cm(2)) and three days before to UV exposure each animal received 1 drop/day of vehicle in one eye and 1 drop/day of vehicle containing 4-CA (164ng) in the contralateral eye. Corneal and sclera tissues were removed and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels were measured. Superoxide dismutase (SOD) and xanthine oxidase (XO) activities were determined in aqueous humour. UVB-induced vessel hyper-reactivity was strongly reduced at 4 and 24h after UVB exposure after local treatment with 4-CA, 8-oxodGuo levels, a marker of oxidative DNA damage, were significantly increased (P<0.05) in sclera and cornea by UVB irradiation, but when 4-CA was administered to the conjunctiva in a buffered solution once a day for 3d before and 6d after UVB exposure, levels of 8-oxodGuo were similar to controls and significantly reduced (P<0.05) compared to UVB-treated corneas. XO activity in the aqueous humour was significantly increased. The administration of 4-CA for 3d before and 6d after UVB irradiation induced a small but significant (P<0.05) reduction of XO compared with control eyes. Our results indicate that the administration of 4-CA protects eye tissues, thus reducing the harmful effect of UVB radiation at low concentration, probably through its free radical scavenging and antioxidant properties. Therefore, 4-CA may be useful in protecting the eye from free radical damage following UVB exposure from sunlight, UV lamps and welding torches.
Department of Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy. maura.lodovici@unifi.it
Maura
M
Lodovici
Silvia
S
Caldini
Lucia
L
Morbidelli
Victor
V
Akpan
Marina
M
Ziche
Piero
P
Dolara
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D001082:Aqueous Humor / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects; D003315:Cornea / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects; D003373:Coumaric Acids / Q000494:pharmacology*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005123:Eye / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D011422:Propionates; D011817:Rabbits; D011837:Radiation-Protective Agents; D012590:Sclera / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects; D013482:Superoxide Dismutase / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects*; D014969:Xanthine Oxidase / Q000378:metabolism
D003373:Coumaric Acids; D011422:Propionates; D011837:Radiation-Protective Agents; D000080242:8-Hydroxy-2'-Deoxyguanosine; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D003849:Deoxyguanosine; C495469:p-coumaric acid