Abstract
Purpose:
To examine whether green tea polyphenols prevent the cataract formation induced by glucocorticoid in chick embryo.
Methods:
Hydrocortisone hemisuccinate sodium (HC) (0.5 μmol / egg) was administered directly into the air chamber in the egg shell of chick embryo day 15. The eggs were then kept in an incubator at same conditions and administered 200 μl of green tea polyphenols (1.00 mg / ml), or saline (control) 3, 10, 20 hr after administration of HC. After 48 hr of treatment, lenses were removed from embryo and classified into five stages according to developed opacity: 1, no lens opacity; 2, faint white ring in the periphery of the lens nucleus; 3, clear white ring in the periphery of the lens nucleus; 4, opacity of the lens nucleus not spreading to the center of the nucleus; 5, opacity of the lens nucleus spreading to the center of the nucleus. The amounts of reduced glutathione in the lenses were measured.
Results:
The opacity scores of control lenses and lenses treated with green tea polyphenols were 3.80 ± 1.24 and 1.42 ± 0.69 (p < 0.001), respectively. Administration of green tea polyphenols decreased the lens opacity. The amounts of reduced glutathione in control lenses and lenses treated with green tea polyphenols were 5.41 ± 0.46 nmol/lens and 7.10 ± 0.88 nmol/lens (p < 0.001), respectively. Administration of green tea polyphenols recovered its decrease.
Conclusions:
These findings support that green tea polyphenols protect glucocorticoid-induced cataract in chick embryo via its anti-oxidative effect.