以強迫游泳試驗探討金針花乙醇萃取物之抗憂鬱效果

Abstract

根據2008年世界衛生組織（world health organization, WHO）最新的報告預估，憂鬱症將於2030年成為世界排名第一的高負擔疾病。雖然目前已研發出多種抗憂鬱藥物，但藥物治療卻伴隨著許多副作用，使病人的治療順從性不高。金針（Hemerocallis fulva L.），《說文解字》名為「忘憂」，《本草綱目》又名為「療愁」，顧名思義其為中國傳統食療之安神良方。近代研究發現，金針花具有極佳之抗氧化活性，且可幫助睡眠與增強記憶力；而其所含之重要黃酮類成分，芸香素（rutin）亦被發表具有抗憂鬱之功效。因此本研究以金針花乙醇萃取物及芸香素為素材，採用強迫游泳試驗及腦部單胺類神經傳導物質含量分析，來探討其抗憂鬱效果。結果顯示，不論是短期或是長期試驗，給予金針花乙醇萃取物與芸香素之組別在強迫游泳試驗中的不活動時間均明顯低於控制組，且游泳時間顯著性增加，掙扎時間則沒有統計差異（p < 0.05）。進一步分析單胺類神經傳導物質後發現，金針花乙醇萃取物及芸香素能有效增加腦部血清素、正腎上腺素與多巴胺的含量（p < 0.05）。尤其金針花乙醇萃取物對血清素的影響最為顯著，在長期試驗中，所有腦區均出現顯著增加的情形，其代謝速率更在杏仁核（40.0~60.7%）、海馬迴（30.0~47.9%）及紋狀體（18.3~40.7%）明顯降低，並以杏仁核之下降幅度最大。此外，根據攝食量及體重變化量之結果，發現金針花乙醇萃取物與芸香素並不會造成如fluoxetine所伴隨的副作用。綜合以上，證實金針花乙醇萃取物確實可透過調控血清素傳導系統達到抗憂鬱效果，並且不會造成食慾下降及體重減輕之副作用產生，而芸香素則為其重要的抗憂鬱活性成分。

According to the prediction of 2008 WHO report, depression will be the worldwide No. 1 high burden disease by the year 2030. Although various antidepressants are commercially available, the accompanied side effects are not good for therapeutic compliance. Hemerocallis fulva L., also known as daylily, is traditionally used for soothing in Chinese dietary therapy. Recent researches discovered that daylily flowers containing potent antioxidative activity, and is good for improving sleep and memory. Rutin, a key flavonoid in daylily flowers, is also characterized as a candidate for antidepressant. In this study we investigated the antidepressant effects of ethanol extract of daylily flowers and rutin by forced swimming test and brain neurotransmitter content analysis. Our results showed that in both short term and long term test, the experimental groups of daylily flowers extract and rutin exhibited significantly reduction of immobility time in forced swimming test, and increased swimming time compared with the control group but not struggling time (p < 0.05). Further analysis on monoamines indicated that the daylily flowers extract and rutin could increase the contents of serotonin, norepinephrine and dopamine in brain (p < 0.05). In long term test, the daylily flowers extract markedly increased serotonin in whole brain and reduced serotonin turnover rate in amygdala (40.0~60.7%), hippocampus (30.0~47.9%), and striatum (18.3~40.7%), especially in amygdala (p < 0.05). Additionally, we found that daylily flowers extract and rutin did not cause food intake disorder and body weight loss which are the side effects of fluoxetine. In conclusion, present data illustrated that ethanol extract of daylily flowers does have antidepressant like effects possibly via the regulation of serotonergic system and has no side effects of reduction in body weight and appetite. Moreover, rutin might be playing a very important role in the antidepressant like effects of ethanol extract of daylily flowers.