三十種中藥粗抽提物致突變性作用之測定

Mutagenicity Testing of the Crude Extracts of 30 Chinese Drugs

為了評估中藥是否具有致突變性，本研究就「中華民國中藥典範」中之三十種中藥粗抽提物，包指：人參，山楂，大薊，大棗，三七，仙茅，白茅紋，地骨皮，全蠍，牡丹皮，防風，杜仲，決明子，車前子，吳茱萸，青葙子，海帶，桃仁，桑寄生，夏枯草，馬兜鈴，鉤藤，側柏葉，黃芩，黃精，菊花，葛根，當歸，貕薟等之50%乙醇抽提物及夏枯草，黃連等之熱水抽提物，以沙門菌回復突變測試法[Salmonella/microsome(Ames)test]及活體外非排定DNA合成測定法[in vitro unscheduled DNA synthesis (UDS)assay]做致突變性測定。Ames test採用直接平板混合法；使用之菌種Salmonella typhimurium TA98及TA100，而以含大白鼠肝臟微粒體活化酵素之S9混合液當代謝性活化劑。如以所測定樣品引起逆突變菌落數增為自然突變菌落數之二倍以上即判定該樣品具有致突變能力，則結果顯示，當測試劑量為每平板合相當於0.25公克原中藥材重量時，於TA98中有馬兜鈴(-S9)，菊花（+與59），吳茱英（+與－S9）及夏枯草（+與S9）；於TA100中則有馬兜鈴(-S9)及黃芩(-S9)。當劑量降為每平板含0.125公克時，除夏枯草外，其餘均無作用。如以50%乙醇抽提物測試，於S9存在下，每平板含0.063公克夏枯草對TA98還有作用；但如以熱水抽提物測試，則劑量雖達每平板含0.31公克亦無作用。黃連（每平板含0.02公克）對TA98有致突變能力但對TA100則無。UDS assay採用人類成纖維細胞株(CRL1508)及液相閃爍計數(LSC)測定法。結果顯示，30種中藥抽提物(2-200mg/ml)可與濃度有關地抑制氘標示之胸嘧啶甘[3H]thymidine）併入人類成纖維細胞DNA。於10mM hydroxyurea存在下之UDS則只有地骨皮(10-20mg/ml)顯示有三倍增加，暗示地骨皮含有會破壞DNA之成份。綜合上述，馬兜鈴，菊花，吳茱萸，地骨皮，夏枯草，黃芩等之50%乙醇抽提物及黃連熱水抽提物被測試顯示具有致突變性潛力。

To evaluate whether the commonly used Chinese drugs have mutagenicity, the crude extracts of 30 Chinese drugs were tested with the Salmonella/microsome (Ames) test and the in vitro unscheduled DNA synthesis (UDS) assay in the absence (-) or the presence (+) of S9 mix as a metabolic activator. In the Ames test, the results showed that at the dose of 0.25 g1plate the 50% ethanol extracts of Aristolochiae Fructus (ArF, -S9), Chrysanthemia Flos (ChF + and -S9), Evodiae Fructus (EvF, + and -S9), and Prunellae Spica (PrS+ and -S9), were mutagenic on Salmonella typhimurium TA98; whereas ArF (-S9) and Scutellariae Radix (ScR, -S9) were mutagenic on TA100. These drugs, except PrS, were negative at the dose of 0.125 g1plate. At the dose of 0.063 g/plate, PrS still showed mutagenic activity on TA98 in the presence of S9 mix. In contrast, the water extract of PrS was negative at the doses up to 0.31 g/plate. At the dose of 0.02 g/plate, the water extract of Coptidis Rhizoma (CoR) was mutagenic on TA98, but not on TA100. In the UDS assay with human fibroblast cells, the results showed that 30Chinese drugs (2-200mglml) decresed [3H] thymidine incorporation into DNA in a concentration-dependent manner. In the presence of 10 mM hydroxyurea, only Lycii Radicis Cortex (LyRC. 10-20 mg/ml) induced a 2-fold increase in UDS, suggesting that LyRC might contain substance(s) to cause DNA damage. In summary, the 50% ethanol extracts of ArF. ChF, EvF, LyRC, PrS, and ScR and the water extract of CoR were considered to have mutagenic potential.