探討預先處理baicalein對於甲基安非他命引發小白鼠紋狀體多巴胺系統神經毒害之研究   全文下載

Baicalein Reverses the Methamphetamine-Induced Striatal Dopaminergic Neurotoxicity in Mice

本研究的目的在於探討中藥Scutellaria baicalensis Georgi黃芩主要成分之一的baicalein（5,6,7-trihydroxyflavone）是否能減緩甲基安非他命所引發的神經毒害。實驗利用雄性ICR小白鼠，於一天之內每隔二小時經由腹腔注射（intraperitoneal; i.p.）分別給予一針甲基安非他命（5 mg/kg）或saline共注射4次，並於注射前30分鐘注射baicalein（1 mg/kg）。實驗動物於注射完最後一針算起的第1、第24小時，和第3天後斷頸犧牲，並取出小白鼠腦中的紋狀體（striatum）核區，分別進行多巴胺以及NO的濃度測試。結果顯示甲基安非他命會造成紋狀體內多巴胺含量下降與延緩NO的形成，而baicalein顯著的逆轉甲基安非他命造成多巴胺耗損的現象，並且在3天後baicalein仍可以將腦中紋狀體NO的含量維持在高濃度下。綜合實驗結果，推測baicalein可能透過NO來逆轉甲基安非他命造成紋狀體中多巴胺含量的下降。"

The potential for neuroprotection by baicalein (5,6,7-trihydroxyflavone), a major constituent from the root of a widely used Chinese medicinal herb Scutellaria baicalensis Georgi, against methamphetamine-induced neurotoxicity was studied. All ICR mice were treated by 4-times repeated intraperitoneal administration, at 2 hr intervals, of either methamphetamine (5 mg/kg), saline, baicalein (1 mg/kg) or baicalein pretreatment followed by methamphetamine. In the striatum of mouse, the tissue level of dopamine was monitored on day 3 and nitric oxide was assayed after 1 hr, 24 hrs and 3 days of the above treatments. The results showed that striatal dopamine was significantly depleted by methamphetamine and elevated by baicalein. Pretreatment with baicalein prevented the methamphetamine-induced dopamine depletion. Nitric oxide was depressed by methamphetamine, elevated by baicalein, but remained suppressed with baicalein plus methamphetamine after 1 hr post-treatment. At 24 hrs nitric oxide concentration was unaffected by methamphetamine but was significantly elevated by baicalein or baicalein plus methamphetamine administration. On 3 days post-treatment nitric oxide was elevated by methamphetamine, baicalein and further markedly elevated by the administration of baicalein plus methamphetamine. These results suggest a potential neuroprotective role for baicalein with the possible involvement of nitric oxide.