Kanoh R, Hatano T, Ito H, Yoshida T, Akagi M
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Japan.
Phytomedicine. 2000 Jul;7(4):297-302. doi: 10.1016/S0944-7113(00)80047-1.
The effects of tannins and related polyphenols on KO2- and compound 48/80-induced histamine release from rat peritoneal mast cells were examined. Pretreatment with hydrolyzable tannins (1-100 microM) significantly inhibited KO2-induced histamine release. Dimeric ellagitannins, which have hexahydroxydiphenoyl (HHDP) and valoneoyl residues and/or a valoneoyl-related acyl unit in the molecule, showed more potent inhibitory effects than monomeric hydrolyzable tannins. The most effective inhibition was exhibited by agrimoniin and euphorbin C (IC50 0.68 and 0.80 microM), which have dehydrodigalloyl and euphorbinoyl groups, respectively, as well as the HHDP group. However, procyanidins, flavonoids and related polyphenols with small molecular weights, except for epigallocatechin gallate, exhibited negligible effects. Although clinically used antiallergic drugs, azelastine, astemizole, ketotifen and epinastine have been shown to prevent KO2-induced histamine release, their potencies were all less than those of ellagitannins. An inhibitory effect on compound 48/80-induced histamine release was also exhibited by higher molecular weight tannins. The inhibitory effect on histamine release caused by different stimulants suggested that ellagitannins act as cell membrane stabilizers as well as radical scavengers.
研究了单宁及相关多酚对KO2和化合物48/80诱导的大鼠腹膜肥大细胞组胺释放的影响。用可水解单宁（1 - 100 microM）预处理可显著抑制KO2诱导的组胺释放。分子中含有六羟基二苯甲酰基（HHDP）和戊二酰基残基及/或与戊二酰基相关的酰基单元的二聚鞣花单宁，其抑制作用比单体可水解单宁更强。具有脱氢没食子酰基和千金二萜酰基以及HHDP基团的仙鹤草素和千金二萜醇C（IC50分别为0.68和0.80 microM）表现出最有效的抑制作用。然而，除表没食子儿茶素没食子酸酯外，低分子量的原花青素、黄酮类化合物及相关多酚的作用可忽略不计。虽然临床使用的抗过敏药物氮卓斯汀、阿司咪唑、酮替芬和依匹斯汀已被证明可预防KO2诱导的组胺释放，但其效力均低于鞣花单宁。高分子量单宁对化合物48/80诱导的组胺释放也有抑制作用。对不同刺激物引起的组胺释放的抑制作用表明，鞣花单宁可作为细胞膜稳定剂和自由基清除剂。
