L-Theanine Suppresses Lipid Hydroperoxide-Induced Rabbit Corneal Neovascuralization

Abstract

Purpose:: From our recent studies, the green tee extract fraction which contained more theanine compared with other fractions, suppressed the neovascularization in rat model of oxygen-induced retinopathy. In this study, we investigated the effects of theanine on linoleic acid hydroperoxide (LHP)-induced corneal neovascularization (NV) in a rabbit model.

Methods:: Male New Zealand rabbits received eye drops of 1% or 3% theanine or distilled water as control, 2 times a day for 14 days. Thirty minutes after the first eye drop, LHP was injected with a 30 gauge needle into the corneal stroma of the superior quadrant 4.5 mm below the limbus. The longest vessel length was measured by using castrovieho caliper under a surgical microscope.

Results:: At 14 days post-LHP injection, the longest length was observed to 3.7 ± 0.4 mm in the control animals (n=5), 0.8 ± 0.8 mm in the 1% theanine treated group (n=4, p<0.01 vs. control), and 1.3 ± 1.1 mm in the 3% theanine treated group (n=3, p<0.05 vs. control), respectively.

Conclusions:: These results indicate that LHP-induced corneal NV was inhibited by theanine treatment, it may be an appropriate pharmacological intervention for neovascular disorder.

Keywords: neovascularization • cornea: stroma and keratocytes • antioxidants