| 摘要: | 海巴戟天俗稱Noni，生長在熱帶亞州、夏威夷及塔希提島，其根、莖、葉及果實被應用在很多的傳統醫療上，如高血壓、糖尿病及癌症等。根據本實驗室研究顯示，海巴戟天乙醇萃取物相較於其它溶劑 (去離子水、乙酸乙酯或超臨界二氧化碳萃取法) 具有較高且多樣性的抗氧化能力，且海巴戟天乙醇萃取物含有較高的多酚類及類黃酮含量，而這些成分在抗氧化能力方面扮演了重要的角色。在本研究中我們利用單細胞凝膠電泳技術（慧星試驗）探討海巴戟天褐莖、葉、果實乙醇萃取液及其各正己烷、正丁醇、乙酸乙酯及水層分配相對於由健康人類血液中分離出淋巴球在遭受到氧化壓力時的影響。結果顯示海巴戟天褐莖乙醇萃取液之正己烷分配相 ( BSE-H ) 在低濃度（50 g /mL）時具有顯著保護人類淋巴球細胞抵抗 H2O2 所產生氧化性壓力的效果，然而在 ＞100 g /mL 時卻會增加 DNA 的氧化傷害；而海巴戟天果實乙醇萃取液之水層分配相（FE-A）濃度在 50~200 g /mL，具有顯著保護人類淋巴球細胞抵抗 H2O2 所產生氧化性壓力的效果，然而在高濃度（400 g /mL）時，卻會增加 DNA 的損傷程度。此外，在海巴戟天葉乙醇萃取液之正丁醇及水層分配相中，（LE-B 和 LE-A），以及海巴戟天果實乙醇萃取液之正丁醇分配相（FE-B），濃度在25~400 g /mL 可以保護由 H2O2 對人類淋巴球細胞 DNA 所造成的損傷，且高濃度下（400 g /mL）沒有過氧化的情況產生；另外，在果實乙醇萃取液及褐莖乙酸乙酯層之分配相中，濃度在50~400 g /mL 也能夠安全的減少人類淋巴球細胞 DNA 所造成的損傷。藉由上述發現，我們認為海巴戟天褐莖、葉及果實值得針對活性物質再做更進一步的純化及鑑定的研究，以確定其對生物體造成保護或損傷的機制。
Morinda citrifolia commonly known as Noni, is a plant typically found in the Hawaiian, Tahitian and tropical Asia. The bark, stem, roots, leaves, and fruits have been used traditionally as a folk remedy for many diseases including diabetes, hypertension, and cancers. Based on our previous researches, ethanolic extracts of Noni exhibited higher and variety of antioxidative capacity, which were comparable to other solvents (deionized water, ethyl acetate or supercritical fluid carbon dioxide). Ethanolic extracts of Noni have higher total polyphenol and flavonoid contents and reveal that these compounds play a part in antioxidative activities. In this study, we examined the influences of the ethanolic extracts, n-hexane-, n-butanol-, ethyl acetate-, and H2O-soluble partitioned phases obtained from the brown stem, leaf and fruit of Noni on purified healthy human blood lymphocyte using a single-cell gel electrophoresis assay (comet assay). Results showed that n-hexane partitioned phase from ethanolic extract of Noni’s brown stem (BSE-H) at low concentration of 50 g/mL had significant protection against oxidative stress induced by H2O2, whereas at concentration >100 g/mL caused increased DNA damage. Aqueous partitioned phase from ethanolic extract of Noni’s fruit (FE-A) at concentrations from 50 to 200 g/mL had also significant protection against oxidantive stress induced by H2O2, whereas at high concentration (400 g/mL) caused increased DNA damage. Furthermore, n-butanol and aqueous partitioned phases from ethanolic extracts of Noni’s leaf (LE-B and LE-A), n-butanol partitioned phase from ethanolic extract of Noni’s fruit (FE-B) at concentrations from 25 to 400 g/mL suppressed the DNA strand breakage of human lymphocytes induced by H2O2 , and no pro-oxidant effects would be found. 95% ethanolic extract of Noni’s fruit (FE) and ethyl acetate partitioned phase from ethanolic extract of Noni’s brown stem (BSE-EA) at concentrations from 50 to 400 g/mL could suppress the breakage of DNA strand, and be safe to human lymphocytes. From these findings, we suggest that Noni’s brown stem, leaf and fruit are worth further research in purification and identification of active compounds, and will help determine mechanism of protection or damage by phytochemicals. |
