以Balb/c小鼠為模式探討三種不同分子量之蒟蒻水解物對直結腸癌危險因子的影響

Modulatory effects of three konjac hydrolysate fractions on risk factors of colon cancer in Balb/c mice

林友梅(You-Mei Lin)

指導教授 ： 陳曉鈴

中山醫學大學/健康管理學院/營養學研究所/碩士(2007年)

https://doi.org/10.6834/CSMU.2007.00078

摘要

蒟蒻主要成分是葡甘聚醣（glucomannan），是一種可溶性纖維；由D-葡萄糖和D-甘露糖以ß-1,4醣甘鍵鍵結而成。本研究目的將比較未水解蒟蒻纖維、三種不同分子量之蒟蒻纖維部分水解物（平均聚合度為16，8，4）對大腸癌之預測生物指標（如糞便水液成分對人類大腸腺癌細胞株產生之毒性）及影響這些作用的因素（如糞便pH、短鏈脂肪酸濃度及致癌相關細菌酵素活性等）的調控作用。
將六週齡之Balb/c小鼠隨機分配，每組12隻，分別餵食不含纖維及含5%不同膳食纖維（Cellulose，C；Pectin，P；Konjac glucomannan，K；Konjac glucomannan hydrolysis fraction1、fraction 2、fraction 3，F1、F2、F3；Inulin，I；及Fructooligosaccharides，FO）實驗飲食21天。犧牲前三天（第18-20天）連續收集72小時糞便並馬上冷凍保存。隔夜禁食後第22天犧牲，採集血液及大腸，並秤取肝臟及盲腸內容物重冷凍儲存於-20℃冰箱。
結果顯示飼料攝取量以FO組較高，食物利用率方面則是以K組利用率最低，然而在體重增加方面各組間並無差異。相對器官重部份：相對肝臟重以FF組顯著高於其他各組，相對盲腸重部份則是以FO組最高，每日排便乾重部份，除FF組外攝取其他纖維皆可增加糞便乾重。糞便酵素方面ß-glucosidase以F1組活性最高；ß-galactosidase是以P組活性最高；ß-glucuronidase則是以F2組最高。在糞便pH值及短鏈脂肪酸含量部份，糞便pH值以P組最低與攝食其他膳食纖維的pH值相似，C組最高；在每日短鏈脂肪酸排出量方面，不論是乙酸、丙酸、正丁酸或異丁酸皆以F3組最高；乙酸、正丁酸或異丁酸FF組最低。
在糞便水細胞及DNA傷害測試部分，細胞毒性測試結果顯示；補充任何一種膳食纖維皆可以改善糞便水對細胞之毒性；DNA傷害測試方面，以FF組傷害程度最大，P及I組的DNA傷害程度最低；近一步以H2O2誘發DNA傷害發現，以FF組傷害程度最大，F3組的DNA傷害程度最低。
縱合上述結果顯示，蒟蒻水解物F3（DP≒4）在腸道發酵產生的短鏈脂肪酸最高，且對於改善糞便水對於細胞毒性及DNA傷害效果最顯著。

關鍵字

蒟蒻 ； 葡甘聚醣 ； 蒟蒻水解物 ； 短鏈脂肪酸 ； 糞便細菌酵素 ； 細胞毒性 ； DNA傷害 ； 彗星影像分析

並列摘要

Konjac, a soluble dietary fiber, is rich in glucomannan polysaccharides which is composed of D-glucose and D-mannose by ß-1,4 glycosidic bond. The purpose of this study was to compare the effect of Konjac（K）, Konjac hydrolysate fractions（F1, F2, F3; the degree of polymerization was 16, 8, 4 respectively）, inulin（I）, fructooligosaccharide（FO）, pectin（P）and cellulose（C）on the concentrations of short chain fatty acids（SCFA）in the feces, and the fecal enzyme, fecal water pH, the cytotoxicity and DNA damage on Caco-2 cell.
The 6-wk-old Balb/c mice were randomly allocated to consume AIN-93 control fiber-free（FF）, and 5% K, F1, F2, F3, I, FO, P or C diet for three weeks. The feces of mice were collected for three days before sacrifice. The mice were sacrificed on the 22nd day. After sacrificing, the main organs was collected and weighted to analyze.
There were no differences in body weight gain across groups. FO group has the highest daily food intake, and K group has the lowest food efficiency. FF group has the highest liver relative weight, and FO group has the highest cecum relative weight. All of the fiber used in this study can increase the daily feces dry weight.
On the fecal enzyme, F1 group has the highest ß-glucosidase activation; P group has the highest ß-galactosidase activation; F2 group has the highest ß-glucuronidase activation. Compare the fecal SCFA, F3 group has the highest concentrations of fecal acetate, propionate, and butyrate.
In the cytotoxicity on Caco-2 cell, all of the fiber used in this study can improve the fecal water induce cell toxicity. In the DNA damage on Caco-2 cell, P and I group has the lowest DNA damage. After using the H2O2 inducing DNA damage, F3 group has the best effect on prevent DNA from H2O2 damage.
In conclusion, the Konjac hydrolysate fractions 3（DP≒4）could increase the concentrations of fecal short chain fatty acids, and prevent the Caco-2 cell from fecal water damage.

並列關鍵字

konjac ； glucomannan ； konjac hydrolysate fractions ； short chain fatty acid ； fecal enzyme ； cytotoxicity ； DNA damage ； comet assay

參考文獻

61. 吳文慈. 蒟蒻補充劑對人體大腸癌發生相關因子之調節作用. 中山醫學大學營養科學研究所碩士論文 2005.

1. 行政院衛生署. 行政院衛生署 衛生統計資料網. 2005.

39. 劉守芬, 林怡希, 蔡敬民. 生技合成難消化性寡醣與聚糊精能改善成年男子排便與糞臭素之產生. 中華民國營養學會雜誌 1994;19.

18. 劉淑媛. 蒟蒻纖維補充劑對成年人排便特性及糞便組成之影響. 中山醫學大學營養科學研究所碩士論文 2005.

3. Zaridze DG. Environmental etiology of large-bowel cancer. J Natl Cancer Inst 1983;70:389-400.