Effects of Topical Instillation of Traditional Herbal Medicines, Herbal Extracts, and Their Components on Prostaglandin E 2-induced Aqueous Flare Elevation in Pigmented Rabbits

Abstract

Purpose: To evaluate the effect of topical instillation of traditional herbal medicines, herbal extracts, and their components on the elevation of aqueous flare induced by prostaglandin E 2 (PGE 2) in pigmented rabbits. Methods: Transcorneal diffusion of 25 μg/mL of PGE 2 was carried out through a glass cylinder placed on the cornea to induce aqueous flare elevation in pigmented rabbits. Traditional herbal medicines, herbal extracts, and their components were topically instilled before the PGE 2 application. Aqueous flare was measured with a laser flare-cell meter. Results: Two instillations, 60 and 30 minutes before PGE 2, of Kakkon-to, Sairei-to, Orengedoku-to, Senkanmeimoku-to, Scutellariae radix extract, Coptidis rhizoma extract, Gardeniae fructus extract, Phellodendri cortex extract, baicalein, baicalin, wogonin, crocetin, berberine, or glycyrrhizine did not inhibit the elevation induced by PGE 2. Two instillations, 60 and 30 minutes before PGE 2, of a Ligusticum wallichii extract (100 mg/mL) inhibited the elevation by 20%. Two instillations (5 and 3 hours before PGE 2) of baicalein (1 mg/mL) or baicalin (5 mg/mL) inhibited the elevation by 16% and 24%, respectively. Two instillations, 5 and 3 hours before PGE 2, of wogonin, crocetin, berberine, or glycyrrhizine did not inhibit the elevation. Conclusion: Two instillations of Ligusticum wallichii extract 60 and 30 minutes before the PGE 2, and two instillations of baicalein or baicalin, 5 and 3 hours before the PGE 2, inhibited the PGE 2-induced aqueous flare elevation in pigmented rabbits.