| 摘要: | (第一部份) 黃酮類因其廣泛而優越的生物活性，近年來引起研究之熱潮。黃蘗素-7-葡萄糖?(phellamurin) 是台灣黃蘗葉中含量頗豐的一種雙氫黃酮類配醣體。本研究探討黃蘗素-7-葡萄糖?在大白鼠體內之代謝與動力學。大白鼠口服100 mg/kg和200 mg/kg兩種劑量，檢測經 β-glucuronidase/sulfatase水解之前及之後的neophellamuretin血清濃度。定量方法係採用高效液相層析法，移動相為氰甲烷-1% 醋酸 (38︰62)。結果顯示黃蘗素-7-葡萄糖?完全不被吸收，而其?元及glucuronides結合態代謝物出現在血中。口服兩種劑量後，黃蘗素-7-葡萄糖?代謝物的總暴藥量中，自由態的neophellamuretin皆約佔20 %，neophellamuretin glucuronides則約佔80 %。 大白鼠口服100 mg/kg和200 mg/kg兩種劑量，於給藥後0.33， 2， 4及6小時將大白鼠犧牲，分析腦中黃蘗素-7-葡萄糖?之代謝物。定量方法係比照血清濃度之測定採用相同的高效液相層析法。結果顯示neophellamuretin glucuronides結合態代謝物可能穿越血腦障蔽，其腦中之濃度呈現劑量相關性，而neophellamuretin在腦中的含量則極微。 環孢靈 (cyclosporin)是一個治療指數狹窄的常用抗排斥藥物，它為P-glycoprotein (Pgp) 與cytochrome P450-3A4 (CYP 3A4)的受質。大白鼠體外翻腸試驗結果顯示，黃蘗素-7-葡萄糖?會抑制小腸Pgp之功能。為了探究黃蘗素-7-葡萄糖?對環孢靈在體內動力學的影響，以大白鼠單服5 mg/kg環孢靈或併服與100 mg/kg黃蘗素-7-葡萄糖?。利用螢光偏極免疫分析法檢測血中環孢靈濃度。結果顯示併服黃蘗素-7-葡萄糖?顯著降低環孢靈之血峰濃度 (Cmax) 達77 %，而濃度時間曲線下面積 (AUC0-∞) 顯著減少56 %，排除半生期則未受影響。此結果顯示併服黃蘗素-7-葡萄糖?明顯降低環孢靈之吸收。 長葉毛地黃?(digoxin)對大白鼠是Pgp與CYP 3A4之受質，為了探究黃蘗素-7-葡萄糖苷對長葉毛地黃?體內動力學的影響，以交叉試驗設計予大白鼠單服0.04 mg/kg長葉毛地黃?或併服100 mg/kg黃蘗素-7-葡萄糖?。利用螢光偏極免疫分析法檢測血清中長葉毛地黃?濃度。結果顯示之AUC4-12 明顯高於控制組AUC4-12 達47 %，平均達峰時間 (Tmax ) 明顯地延後約4.4小時，平均滯留時間 (MRT) 實驗組明顯地增長約1.5小時。 我們建議使用環孢靈或長葉毛地黃?之病患，應盡量避免併服黃蘗素-7-葡萄糖?或台灣黃蘗葉及川黃蘗，以確保用藥之療效與安全。 對於病人移植器官排斥之預測，環孢靈的AUC是一個準確的指標。本研究探討大白鼠口服環孢靈後，以其Cmax預估AUC的可行性。大白鼠口服環孢靈新劑型 (Neoral®) 5.0，2.5及1.25 mg/kg後，各劑量組之C1與AUC0-t 的相關係數分別為0.86、0.91及0.90。顯示環孢靈給藥後，單獨監測C1可預估Neoral® 在大白鼠之生體可用率。因此以此單點監測模式應可提供作為環孢靈製劑之生體可用率或環孢靈與其他藥物交互作用之快速體內預試驗。 (第二部分) 山黃麻之基源為榆科(Ulmaceae)植物Trema orientalis。由其莖皮及葉部分離得到了二十三個化合物，經光譜測定與文獻比對光譜資料後，確定了二十個化合物之結構式，此二十個化合物分別為: betunilic acid, 3-acetyloleanolic acid, 3-acetylursolic acid, α-amyrenone, simiarenol, simiarenone, α-amyrin, 6β-hydroxystigmast-4-en-3-one, stigmast-4-en-3,6-dione, progesterone, β-sitosterol, β-sitosteryl glucoside, p-hydroxybenzaldehyde, 4,6-dimethyl-5-methoxysalicylic acid, benzoic acid, p-hydroxybenzoic acid, methyl vanillate, methyl 4-methoxycinnamate, methyl cinnamate及 N-p-coumaroyltyramine。 將分離得到的成分進行生物活性試驗，結果顯示抑制過氧化物游離根形成(superoxide formation)作用，3-acetylursolic acid的IC50 約為 3μM，有強烈抑制過氧化物游離根形成活性，大約是positive control 的兩倍活性。stigmast-4-en-3,6-dione有些微抑制過氧化物游離根形成作用。β-sitosteryl glucoside不但沒抑制作用，反而增加superoxide 的量。化合物1、2、3、9、11及12幾無抗過敏及抗血小板凝集作用。; (I) part Flavonoids, possessing various beneficial biological activities, attract increased interest in recent years. Phellamurin is a flavonoid glycoside that is abundant in the leaves of Phellodendron wilsonii Hayata et Kanehira (Rutaceae). The metabolism and disposition of phellamurin were investigated in rats. Doses of 100 mg/kg and 200 mg/kg were orally administered to rats and blood samples were withdrawn by cardiopuncture at specific times. Serum concentrations of the aglycone were determined by an HPLC method prior to and after hydrolysis with b-glucuronidase/sulfatase. The mobile phase was acetonitrile-1% acetic acid (38:62). Our results indicate that the parent compound was not absorbed. Hydrolysis to neophellamuretin resulted in rapid absorption and subsequent conversion to glucuronides. Neophellamuretin and neophellamuretin glucuronides accounted for 20 % and 80 % of the metabolites of phellamurin, respectively, for both doses. The disposition kinetics of phellamurin metabolites in rat brain was investigated in this study. Doses of 100 mg/kg and 200 mg/kg were orally administered to rats. At 0.33, 2, 4 and 6 hr after dosing, rats were sacrificed and the brain concentrations of the aglycone neophellamuretin were determined by an HPLC method described above. Our results indicate that neophellamuretin glucuronides might be able to cross the blood-brain barrier and its concentrations in the brain was dose-dependent at the two doses investigated, whereas the aglycone neophellamuretin was only a trace in the brain. Cyclosporin is an immunosuppressive agent with a narrow therapeutic window. Cyc |
