果寡醣降低D-半乳糖注射Balb/c小鼠氧化壓力之作用

Fructo-oligosaccharides ameliorates the oxidative stress in Balb/c mice treated with D-galactose

郭怡文(Yi-Wen Kuo)

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(2010年)

摘要

研究目的：探討補充果寡醣對於以D-半乳糖誘發的Balb/c雄性小鼠，其體內氧化壓力的調節情形。
實驗設計與方法：將12週齡雄性Balb/c小鼠分為五組：自然老化組、控制組、D-半乳糖誘發老化組、D-半乳糖+果寡醣組(5 % w/w)及D-半乳糖+維生素E組(0.2 % w/w)。各組皆以標準飼料餵飼，除自然老化組未接受注射並於47週齡犧牲外，其餘各組於犧牲前連續51天接受皮下注射生理食鹽水或10 % D-半乳糖生理食鹽水(1.2 g/kg.BW)以誘發老化之氧化壓力。禁食24小時後以CO2昏迷犧牲，由右心房採血分離紅血球，並經生理食鹽水灌流後採集肝臟儲存於-80℃冰箱，以待測定過氧化產物及抗氧化酵素活性。另外迅速分離小腸及大腸黏膜細胞，利用彗星電泳法(comet assay)檢測細胞DNA傷害程度，並將部分細胞以20 - 40 μM過氧化氫處理後，再觀察腸道細胞DNA傷害程度，作為抵禦氧化壓力指標。
結果：結果顯示D-半乳糖成功誘發氧化傷害，D-半乳糖與自然老化過程皆顯著增加紅血球超氧歧化酶活性及血漿、肝臟丙二醛、肝臟8-hydroxy-2-deoxy guanosine (8-OHdG)等過氧化產物的濃度，並顯著增加小腸及大腸黏膜細胞DNA損傷的程度。分離的大腸細胞在接受體外過氧化氫刺激下，D-半乳糖及自然老化組小鼠的DNA傷害程度高達控制組的三倍以上。此外，D-半乳糖也顯著提高紅血球麩胱甘肽過氧化酶活性，但對過氧化氫酶活性的作用並不顯著。果寡醣調降D-半乳糖誘發之氧化壓力效果類似抗氧化劑維生素E，除有效降低紅血球超氧歧化酶活性外，並顯著抑制血漿、肝臟丙二醛，肝臟蛋白羰基及8-OHdG的濃度。在D-半乳糖誘發的腸道黏膜細胞DNA損傷方面，果寡醣及維生素E皆有效降低小腸及大腸黏膜細胞之DNA損傷至與控制組相似，再進一步經體外過氧化氫誘發氧化壓力，發現果寡醣及維生素E組皆仍維持腸道細胞DNA完整性至與控制組相似。
結論：本實驗顯示，果寡醣有助於調節D-半乳糖誘發的Balb/c雄性小鼠其全身性的抗氧化作用，包括血液、肝臟、腸道，降低誘發所產生的過氧化產物及保護腸道細胞抵抗氧化壓力、減少細胞DNA損傷，可能具有延緩老化的潛力。

關鍵字

果寡醣 ； D-半乳糖 ； 丙二醛 ； 蛋白羰基 ； 8-hydroxy-2-deoxy guanosine ； DNA傷害

並列摘要

Objectives: To determine effects of FO on oxidative status in the liver, intestine, and blood in an aging model, D-galactose (DG) treated mice.
Materials and Methods: Twelve–week-old male Balb/c mice were divided into five groups: natural aging (NA), control (saline, s.c.), DG (1.2 g/kg BW, s.c.), DG + FO (5 % w/w diet), DG + Vitamin E (0.2 % w/w diet). All groups were fed standard rodent chow. The NA group was sacrificed at 47 weeks old, while the others were sacrificed after 51 days of treatment. Fasting bloods were collected from the right ventricle before mice were perfused with ice-cold saline. The liver was dissected for analyses of peroxidative products. The intestinal epithelium cells were isolated for analysis of DNA damage using a single cell electrophoresis (comet assay). The cells were further challenged with 20 - 40 μM H2O2 to determine their abilities to defend free radicals.
Results and Findings: Results indicated the DG treatment mimicked the natural aging process that promoted the erythrocyte superoxide dismutase (SOD) activity, plasma malondialdehyde (MDA), hepatic protein carbonyls and 8-hydroxy-2-deoxy guanosine (8-OHdG) levels, and DNA damage in the epithelium cells of the intestines. With H2O2 treatments, the DNA damage of the epithelium cells in the DG and NA groups was triple of that in the control group. FO modulated the DG-induced oxidative stress similarly to the antioxidant vitamin E. FO significantly reduced the erythrocyte SOD activity, MDA levels in the plasma and liver, protein carbonyls and 8-OHdG levels in the liver. FO and vitamin E effectively diminished the DG-induced epithelial cell DNA damage and maintained the epithelial cell DNA integrity to the levels similar to the control group after challenged with 20 - 40 μM H2O2.
Conclusion: This study indicated that FO contributed systemic anti-oxidation and effectively reduced the DG-induced oxidative stress. Therefore, FO could be a potential functional food to delay aging process.

並列關鍵字

fructo-oligosaccharides ； D-galactose ； malondialdehyde ； protein carbonyls ； 8-hydroxy-2-deoxy guanosine ； DNA damage

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