狼尾草台畜草二號對於methotrexate誘導氧化壓力及小腸損傷的影響

狼尾草台畜草二號主要用於生機飲食中牧草汁，生機飲食為癌症化療患者於治療前後常尋求之飲食療法。本研究主要探討狼尾草台畜草二號抗氧化活性及其對化療藥物methotrexate (MTX) 誘導氧化壓力及小腸損傷之影響。評估不同來源狼尾草水及酒精萃取物內之總多酚含量及其體外抗氧化活性；同時，飲食給予Wistar大鼠2.5 %、7.5 % 狼尾草乾燥粉末或管餵50、150 mg/rat狼尾草酒精萃取物，狼尾草介入後21天以腹腔注射MTX (20 mg/kg BW)，第28天進行強迫游泳試驗，後再進行第二次20 mg/kg BW之MTX注射，並分別於第14天及第24天採其尾靜脈血液，第30天進行動物犧牲。結果顯示，市售狼尾草乾燥粉末酒精萃取物有較高總多酚類物質及抗氧化活性；狼尾草飲食一個月不影響MTX未健康大鼠之體力及血液生化值，雖對肝腎組織有急性損傷，但能顯著降低小腸脂質過氧化物 (TBARS) 的產生；MTX雖不影響動物體重、平均攝食量、體力及小腸黏膜結構損傷，但可造成腹瀉、降低白血球數目、萎縮的小腸絨毛高度及腺窩深度並亦造成腎臟急性損傷，與較低的小腸glutathione (GSH) 含量及myeloperoxidase (MPO) 活性；預先21日狼尾草飲食雖無法回復MTX誘導白血球數量減少、空腸絨毛高度或腺窩深度、迴腸MPO氧化壓力損傷或抗氧化物質GSH含量，但能夠舒緩MTX造成的腹瀉發生，增加小腸黏膜結構完整性，並可降低小腸脂質過氧化物 (TBARS) 含量、增加腎臟GSH含量、對於腎臟MPO氧化壓力損傷也有較好的效果。總言之，一個月狼尾草飲食對動物不造成血液毒性，雖能減緩MTX造成的腹瀉發生，但無法回復因MTX誘導的小腸絨毛及氧化壓力損傷，顯示狼尾草可些微舒緩化療藥物MTX造成的副作用，對小腸絨毛結構可能有保護的作用。

關鍵字

狼尾草； methotrexate ；氧化壓力；小腸損傷；癌症化學治療；腹瀉

並列摘要

Napiergrass (NP) is one of the major components in bioorganic drink which is commonly consumed by cancer patients undergoing chemotherapy. This study evaluated the antioxidant activities of different sources of NP. The effects of NP on methotrexate (MTX)-induced oxidative and intestinal damages were also determined. Given Wistar rats 2.5% or 7.5% of napiergrass diet or 50 mg or 150 mg/rat ethanol extracts and MTX was given 20 mg/BW on 21 and 28 days (after forced-swimming test at 28th day). Blood were collected at 14th and 24th days. The animals were sacrificed at 30th day and the tissues were collected for analysis. Results showed that ethanol extracts of commercially available NP powder possessed higher total phenolic compounds and antioxidant activities than others. Administration of NP did not cause physical fatigue nor change blood biochemical values and significantly reduced TBARs levels in ileum but caused urine protein and acute tubular necrosis in healthy rats. On the other hand, MTX treatment did not reduce body weight nor average food intake, but significantly lowered white blood cell counts, caused acute liver and renal damage, induced diarrhea, shortened villus height, crypt depth in jejunum, and decreased glutathione (GSH) contents and myeloperoxidase (MPO) activity in ileum. In addition, administration of NP before MTX for 21 days did not recover white blood cell counts, acute damage of liver and kidney, intestinal villus height or oxidative stress, but ameliorated diarrhea and intestine mucosal injury, increased GSH contents and lowered MPO activity in kidney. In summary, NP decreased the incidence of MTX-induced diarrhea.