- 期刊
伽羅木醇型土肉桂葉子精油之抗氧化及抗阿茲海默症功效
ANTIOXIDANT AND ANTI-ALZHEIMER'S DISEASE ACTIVITIES OF LINALOOL FROM LEAF ESSENTIAL OIL OF CINNAMOMUM OSMOPHLOEUM CT. LINALOOL
摘要
肉桂（Cinnamomum osmophloeum）為臺灣特有樹種之一，依其葉子精油組成分可區分成不同化學品系。本研究使用野生型（Wild-type）秀麗隱桿線蟲（Caenorhabditis elegans）評估伽羅木醇型土肉桂（C. osmophloeum ct. linalool）葉子精油、主成分S-（+）-Linalool及市售R-（−）-Linalool之活體內（in vivo）抗氧化活性，瞭解伽羅木醇（Linalool）對C. elegans氧化壓力之影響。試驗結果顯示，伽羅木醇型土肉桂葉子精油能降低胡桃醌及高溫環境誘導之氧化傷害，顯著提高C. elegans存活率。此外，兩種絕對立體組態的伽羅木醇皆能減輕氧化壓力的傷害，顯示兩種伽羅木醇在C. elegans體內的抗氧化效果一樣好。利用基因轉殖型C. elegans（CL4176 strain）評估伽羅木醇減緩阿茲海默症功效之結果顯示，兩種絕對立體組態的伽羅木醇皆能降低C. elegans癱瘓比率且延長癱瘓時間，減輕類澱粉β胜肽所造成的傷害。進一步偵測基因轉殖型C. elegans體內的活性氧（Reactive oxygen species）變化，結果得知伽羅木醇未能顯著降低基因轉殖型C. elegans體內活性氧含量。綜合上述結果，伽羅木醇型土肉桂葉子精油及其主成分能降低野生型C. elegans之氧化傷害，伽羅木醇亦有潛力成為減緩阿茲海默症之保健食品或藥物。
並列摘要
Cinnamomum osmophloeum is one of the indigenous trees in Taiwan. C. osmophloeum were divided into several chemotypes based on the constituents of the leaf essential oils (EOs). In this study, wild-type Caenorhabditis elegans was employed to investigate the in vivo antioxidant activities of EO and its major constituent, S-(+)-linalool, from C. osmophloeum ct. linalool, and commercially available R-(-)-linalool by assessing the effects of linalool on the survivals of C. elegans under oxidative stresses. The results showed that treatment of the EO of C. osmophloeum ct. linalool increased survivals of C. elegans under juglone-induced and thermal stresses, indicating reductions of oxidative damages. Furthermore, both stereoisomers of linalool reduced oxidative damages, revealing that two stereoisomers possessed similar antioxidant effects in C. elegans. In addition, transgenic C. elegans (CL4176) was used to investigate the protective effects of linalool against amyloid β (Aβ)-induced toxicity. The results demonstrated that both linalool enantiomers effectively delayed Aβ-induced paralysis in the transgenic C. elegans. The levels of reactive oxygen species (ROS) in CL4176 worms were also determined and the results showed that linalool had no effect on the ROS levels in treated worms compared to non-treated worms. Taken together, the results demonstrated that the EO of C. osmophloeum ct. linalool and its major compound linalool enhanced in vivo antioxidant activities in the wild-type C. elegans and suggested that linalool may have a potential neuroprotective role against the Alzheimer's disease.