Effects of Kakkon-to and Sairei-to on Experimental Elevation of Aqueous Flare in Pigmented Rabbits

Abstract

Purpose: To evaluate the possible inhibitory effects of Kakkon-to and Sairei-to, traditional Sino-Japanese herbal medicines, on experimental aqueous flare elevation in pigmented rabbits. Methods: Anterior uveitis was induced either by an application of prostaglandin E 2 (PGE 2), 10 μg/mL, to the cornea, or an intravenous injection of lipopolysaccharides (LPS), 0.5 μg/kg, in an ear vein. Dose dependency of experimental uveitis induced by LPS (0.1, 0.25, 0.5, or 1.0 μg/kg) was also determined. For pretreatment, about 150 g/day of food containing Kakkon-to (1% w/w) or Sairei-to (0.6% or 2% w/w) was given to two groups of animals for 5 days before experimental uveitis was induced. A third group of animals underwent pretreatment with betamethasone, 130 μg/kg, injection into an ear vein 4 hours before experimental uveitis was induced. A fourth group of rabbits with no herbal medicine or betamethasone pretreatment served as controls. Aqueous flare was measured using a laser flare-cell meter. Aqueous flare intensity was expressed as the area under the curve (AUC) in arbitrary units. Results: The increase in aqueous flare induced by LPS was dose-dependent. The AUC of PGE 2 (10 μg/mL) and LPS (0.5 μg/mL) induced aqueous flare elevations were 1,119 and 4,950 arbitrary units, respectively. Kakkon-to (AUC, 1,055) and Sairei-to (AUC, 965) did not inhibit the aqueous flare elevation induced by PGE 2. β-Methasone did inhibit the elevation (AUC, 271). Kakkon-to (AUC, 4,495) did not suppress the aqueous flare elevation induced by LPS. Both 0.6% and 2% Sairei-to (AUC, 2,478, and 978) and β-methasone (AUC, 443) did suppress the aqueous flare elevation induced by LPS significantly ( P < .05). Conclusion: Sairei-to could have an inhibitory effect on experimental anterior uveitis induced by LPS.