Protective effect of 4-coumaric acid from UVB ray damage in the rabbit eye

• Published in: Toxicology (Amsterdam) 2009-01, Vol.255 (1), p.1-5
• Main Authors: Lodovici, Maura, Caldini, Silvia, Morbidelli, Lucia, Akpan, Victor, Ziche, Marina, Dolara, Piero
• Format: Article
• Language: English
• Subjects: 4-coumaric acid; 8-Hydroxy-2'-Deoxyguanosine; 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo); Animals; Aqueous Humor - enzymology; Aqueous Humor - metabolism; Aqueous Humor - radiation effects; Biological and medical sciences; Cornea - enzymology; Cornea - metabolism; Cornea - radiation effects; Coumaric Acids - pharmacology; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - metabolism; Emergency; Eye - enzymology; Eye - metabolism; Eye - radiation effects; Male; Medical sciences; Oxidative Stress - drug effects; Propionates; Rabbit eye; Rabbits; Radiation-Protective Agents; Sclera - enzymology; Sclera - metabolism; Sclera - radiation effects; Superoxide Dismutase - metabolism; Toxicology; Ultraviolet Rays - adverse effects; UVB rays; Xanthine oxidase (XO); Xanthine Oxidase - metabolism
• ISSN: 0300-483X; 1879-3185
• DOI: 10.1016/j.tox.2008.09.011

Abstract 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 (79.2 mJ/cm2 ) 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 (164 ng) 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 24 h 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 3 d before and 6 d 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 3 d before and 6 d 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.