乳酸菌之抗氧化作用：菌體與胞內物抗氧化能力之比較   全文下載

Antioxidative Effect of Lactic Acid Bacteria: Intact Cells vs. Intracellular Extracts

本研究比較兩株乳酸菌Bifidobacterium longum 和Lactobacillus delbrueckii subsp. bulgaricus 其菌體及胞內物的抗氧化能力。結果顯示，B. longum 和L. delbrueckii subsp. bulgaricus 在109 CFU/mL 時，菌體及胞內物具有清除DPPH 自由基能力（70.4-75.1%）、抑制liposome 過氧化（25-31%）以及顯著降低Intestine 407 腸細胞脂質過氧化物（malondialdehyde, MDA）的生成。此外，本研究再進一步利用這兩株具有抗氧化能力乳酸菌的活菌體及其胞內物，探討對腦中風病人（cerebrovascular accident, CVA）和健康受試者血液中低密度脂蛋白（LDL）氧化作用的影響。LDL 的氧化作用是以監測LDL conjugated dienes 形成的起始時間（lag time）為指標。當B. longum 和L. delbrueckii subsp. bulgaricus 以109 cfu/mL 的菌數分別處理LDL 時，LDL 氧化作用的起始時間顯著被延長，健康受試者血液中LDL 氧化被抑制效果優於CVA 病人，而當以B. longum 和L. delbrueckii subsp. bulgaricus 109 CFU/mL 菌數的胞內物處理CVA 病人及健康受試者的LDL 時，LDL 氧化作用的起始時間顯著被延長超過180 分鐘，此結果表示，抑制LDL 氧化作用以乳酸菌的胞內物優於菌體。推論乳酸菌的胞內物具有效的抑制因子。"

The present study compared the anti-oxidative ability of intact cells and intracellular extracts of two lactic acid bacterial strains, Bifidobacterium longum and Lactobacillus delbrueckii ssp. bulgaricus. Results showed that both intact cells and intracellular extracts of 109 cells of B. longum and L. delbrueckii ssp. bulgaricus had the ability to scavengeα-diphenyl-β-picrylhydrazyl (DPPH) free radical by 70.4-75.1%, to inhibit liposome peroxidation by 25-31%, and to decrease significantly the malondialdehyde (MDA) production in Intestine 407 cells. The effect of intact cells and intracellular extracts of these two bacterial strains on the oxidation of low density lipoprotein (LDL) isolated from cerebrovascular accident (CVA) patients and healthy subjects was also compared. Oxidation of LDL was monitored by measuring the lag time for the formation of conjugated dienes in isolated LDL particles. When LDL was treated respectively with 109 intact cells of B. longum and L. delbrueckii ssp. bulgaricus, the lag time of oxidation of LDL was prolonged significantly. The extent of inhibition was greater on LDL isolated from healthy subjects than from CVA patients. When LDL from either CVA patients or healthy subjects was treated with intracellular extracts of 109 cells of B. longum and L. delbrueckii ssp. bulgaricus, respectively, the copper-mediated oxidation was extensively inhibited with a lag time exceeding 180 min. Results from this study show a greater inhibitory effect on LDL oxidation exerted by the intracellular extract than the intact cells, suggesting the presence of effective inhibitory factors in the intracellular extract.