Anti-pruritic effect of baicalin and its metabolites, baicalein and oroxylin A, in mice Anti-tumorPharmacology  

作　　者：Hien-trung TRINH Eun-ha JOH Ho-young KWAK Nam-in BAEK Dong-hyun KIM 

机构地区：[1]Department of Pharmaceutical Science and Department of Life and Pharmaceutical Sciences, Kyung Hee University, 1, Hoegi, Dongdaemun-ku, Seoul 130- 701, Korea [2]Graduate School of Biotechnology and PMRC, Kyung Hee University, 1, Seochunri, Suwon, Kyunggi-Do 449- 701, Korea

出　　处：《Acta Pharmacologica Sinica》2010年第6期718-724,共7页中国药理学报（英文版）

摘　　要：Aim： To explore whether intestinal microflora plays a role in anti-pruritic activity of baicalin, a main constituent of the rhizome of Scutellaria baicalensis （SB）. Methods： Baicalin was anaerobically incubated with human fecal microflora, and its metabolites, baicalein and oroxylin A, were isolated. The inhibitory effect of baicalin and its metabolites was accessed in histamine-or compound 48/80-induced scratching behavior in mice. Results： Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 40.2±26.2 and 1.2±1.1 nmol.h^-1.mg^-1 wet weight of human fecal microflora, respectively. Baicalin （20, 50 mg/kg） showed more potent inhibitory effect on histamine-induced scratching behavior when orally administered than intraperitoneally. In contrast, baicalein and oroxylin A had more potent inhibitory effect when the intraperitoneally administered. The anti-scratching behavior activity of oral baicalin and its metabolites was in proportion to their inhibition on histamine-induced increase of vascular permeability with oroxylin A more potent than baicalein and baicalin. In Magnus test using guinea pig ileum, oroxylin A is more potent than baicalein and baicalin in inhibition of histamine-induced contraction. The anti-scratching behavioral effect of oral baicalin was significantly reduced when oral antibiotics were simultaneously administered, whereas the effect of baicalein and oroxylin A were not affected. Conclusion： Oral baicalin may be metabolized by intestinal microflora into baicalein and oroxylin A, which ameliorate pruritic reactions through anti-histamine action.Aim： To explore whether intestinal microflora plays a role in anti-pruritic activity of baicalin, a main constituent of the rhizome of Scutellaria baicalensis （SB）. Methods： Baicalin was anaerobically incubated with human fecal microflora, and its metabolites, baicalein and oroxylin A, were isolated. The inhibitory effect of baicalin and its metabolites was accessed in histamine-or compound 48/80-induced scratching behavior in mice. Results： Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 40.2±26.2 and 1.2±1.1 nmol.h^-1.mg^-1 wet weight of human fecal microflora, respectively. Baicalin （20, 50 mg/kg） showed more potent inhibitory effect on histamine-induced scratching behavior when orally administered than intraperitoneally. In contrast, baicalein and oroxylin A had more potent inhibitory effect when the intraperitoneally administered. The anti-scratching behavior activity of oral baicalin and its metabolites was in proportion to their inhibition on histamine-induced increase of vascular permeability with oroxylin A more potent than baicalein and baicalin. In Magnus test using guinea pig ileum, oroxylin A is more potent than baicalein and baicalin in inhibition of histamine-induced contraction. The anti-scratching behavioral effect of oral baicalin was significantly reduced when oral antibiotics were simultaneously administered, whereas the effect of baicalein and oroxylin A were not affected. Conclusion： Oral baicalin may be metabolized by intestinal microflora into baicalein and oroxylin A, which ameliorate pruritic reactions through anti-histamine action.

关 键 词：Scutellaria baicalensis BAICALIN BAICALEIN oroxylin A scratching behavior metabolism HISTAMINE 

分 类 号：TQ461[化学工程—制药化工] Q949.32[生物学—植物学]