芝麻素披覆死菌之線蟲壽命試驗模式的開發與芝麻素對人類Hs68細胞壽命之影響

芝麻素是芝麻籽中的木酚素，已知具有抗發炎、降低膽固醇、降血糖、調整脂質代謝、降血壓等生理功效。然而，芝麻素是否具有抗衰老的作用，目前並不清楚？先前有研究報告指出芝麻素可以延長線蟲的壽命，但該研究設計的缺點是未使用E. coli OP50死菌，而且利用價錢昂貴r-CD包覆芝麻素作為線蟲的食物。本研究的目的之一在於開發製備芝麻素披覆死菌作為線蟲食物的方法，並測試此芝麻素披覆死菌是否可以延長線蟲壽命。此外，我們也想探討芝麻素對於高等人類Hs68細胞是否具有延長壽命的作用。我們先將飽和之OP50菌液，經60°C、30分鐘處理後，再與含芝麻素之乙酸乙酯均勻混合一小時，離心，去上清，製備成芝麻素披覆的死菌，供塗抹plate使用。死菌塗抹量定為10mg/plate。結果發現以塗抹含有10%芝麻素之披覆死菌延長線蟲壽命的效果最佳。在細胞試驗上，芝麻素本身不具延緩Hs68細胞衰老的能力，其代謝轉化物enterolactone及enterodiol本身亦無延長細胞壽命的能力。綜合以上結果，芝麻素披覆死菌可以延長線蟲壽命，其製備方法，可供其他脂溶性物質作線蟲壽命試驗之參考，而經由細胞試驗的結果推測，芝麻素延長壽命的作用，可能必須經由活體代謝、體外酵素或微生物作用轉化後，才得以表現，進一步的試驗將著重在於芝麻素經代謝或生物轉化後的產物是否有延長生物體壽命之效果。

Sesamin, a lignan of sesame seeds, has been reported to have anti-inflammatory, lowering cholesterol, blood sugar and blood pressure, adjusting the lipid metabolism, and other physiological functions. However, whether sesamin has anti-senescence effect or not remains unclear to date. A previous study has shown that sesamin can extend the lifespan of C. elegans, but the study used living E. coli as a nematode food instead of using dead E. coli OP50; the study also used expensive r-CD to form a complex with sesamin. Thus, one purpose of this study was to develop a preparation method of sesamin-coated dead OP50 as a nematode food, and test whether sesamin-coated dead OP50 extends lifespan of C. elegans. In addition, we explored whether sesamin could extend lifespan of human Hs68 cells. We first heated saturated the OP50 bacteria at 60 °C for 30 minutes, and then added ethyl acetate containing sesamin, mixed for one hour, centrifuged, and removed the supernatant, to prepare sesamin-coated death OP50. The amount of dead bacteria was set as 10mg / plate, and we found that 10% sesamin in ethyl acetate solution prepared sesamin-coated death OP50 had the most ability to extend the lifespan of C. elegans. On the cell experiment, sesamin did not retard senescence of Hs68 cells, and its metabolic conversion products, enterolactone and enterodiol did not, either. Based on the above results, sesamin-coated dead bacteria can extend the lifespan of C. elegans, the preparation is available for other fat-soluble substances to test lifespan of nematodes. According to the results of cell experiments, we speculated that the effect of sesamin to extend lifespan may express after conversion by metabolism in vivo and by enzymes or microorganisms in vitro. Further investigations will focus on the molecules converted from sesamin by metabolism or biotransformation to extend lifespan of organisms.