PDF(Pubmed)
Abstract：
BACKGROUND: Gum arabic, a polysaccharide exudate from Acacia senegal (L.) Willdenow trees, has already been used by African native people in natural medicine.
METHODS: Using whole-blood samples from young (20-35 years) and older (>80 years) healthy volunteers (each group n = 10), the effect of an aqueous solution of GA on phagocytosis of Escherichia coli was examined with a gentamicin protection assay. Whole-blood samples of each volunteer were stimulated with GA and as a control with CpG oligodeoxynucleotides (Toll-like receptor -9 agonists) for 2 h, then co-incubated with E. coli for 30 min and thereafter treated with gentamicin for up to 240 min to kill extracellular bacteria. Then, whole-blood cells were lysed with distilled water, and colony-forming units were counted by quantitative plating. Cytokine enzyme-linked immunosorbent assay for the detection of TNF-α and IL-6 was performed using the blood supernatant.
RESULTS: The GA concentration tested (20 mg/mL) did not affect the viability of eukaryotic cells. Phagocytosis of E. coli by whole-blood leukocytes derived from young (p = 0.008) and older (p = 0.004) healthy volunteers was increased by 120.8% (young) and 39.2% (old) after stimulation with GA. In contrast, CpG only stimulated the bacterial phagocytosis by cells derived from young volunteers (p = 0.004). Stimulation of whole blood with GA increased the intracellular killing of E. coli in young (p = 0.045) and older volunteers (p = 0.008) and induced a TNF-α release in whole blood collected from older volunteers but not from younger ones (p = 0.008).
CONCLUSIONS: These data encourage the isolation of active compounds of GA and the initiation of clinical trials addressing the preventive effect of GA on bacterial infections.
METHODS: Using whole-blood samples from young (20-35 years) and older (>80 years) healthy volunteers (each group n = 10), the effect of an aqueous solution of GA on phagocytosis of Escherichia coli was examined with a gentamicin protection assay. Whole-blood samples of each volunteer were stimulated with GA and as a control with CpG oligodeoxynucleotides (Toll-like receptor -9 agonists) for 2 h, then co-incubated with E. coli for 30 min and thereafter treated with gentamicin for up to 240 min to kill extracellular bacteria. Then, whole-blood cells were lysed with distilled water, and colony-forming units were counted by quantitative plating. Cytokine enzyme-linked immunosorbent assay for the detection of TNF-α and IL-6 was performed using the blood supernatant.
RESULTS: The GA concentration tested (20 mg/mL) did not affect the viability of eukaryotic cells. Phagocytosis of E. coli by whole-blood leukocytes derived from young (p = 0.008) and older (p = 0.004) healthy volunteers was increased by 120.8% (young) and 39.2% (old) after stimulation with GA. In contrast, CpG only stimulated the bacterial phagocytosis by cells derived from young volunteers (p = 0.004). Stimulation of whole blood with GA increased the intracellular killing of E. coli in young (p = 0.045) and older volunteers (p = 0.008) and induced a TNF-α release in whole blood collected from older volunteers but not from younger ones (p = 0.008).
CONCLUSIONS: These data encourage the isolation of active compounds of GA and the initiation of clinical trials addressing the preventive effect of GA on bacterial infections.
摘要：
背景：阿拉伯树胶，来自阿拉伯胶的多糖渗出物（L.)威尔德诺树，已经被非洲原住民用于天然药物。
方法：使用来自年轻（20-35岁）和年龄较大（>80岁）的健康志愿者（每组n=10）的全血样本，用庆大霉素保护试验检查了GA水溶液对大肠杆菌吞噬作用的影响。用GA刺激每位志愿者的全血样品，并用CpG寡脱氧核苷酸（Toll样受体-9激动剂）刺激2小时作为对照，然后与大肠杆菌共孵育30分钟,然后用庆大霉素处理高达240分钟以杀死细胞外细菌。然后，全血细胞用蒸馏水裂解,和菌落形成单位通过定量平板计算。使用血液上清液进行细胞因子酶联免疫吸附测定以检测TNF-α和IL-6。
结果:测试的GA浓度(20mg/mL)不影响真核细胞的活力。来自年轻（p=0.008）和年长（p=0.004）健康志愿者的全血白细胞对大肠杆菌的吞噬作用在用GA刺激后增加了120.8％（年轻）和39.2％（年老）。相比之下,CpG仅刺激来自年轻志愿者的细胞的细菌吞噬作用（p=0.004）。用GA刺激全血增加了年轻志愿者（p=0.045）和老年志愿者（p=0.008）中大肠杆菌的细胞内杀伤作用，并诱导了从老年志愿者收集的全血中的TNF-α释放，而不是从年轻志愿者（p=0.008）。
结论：这些数据鼓励分离GA的活性化合物，并启动针对GA对细菌感染的预防作用的临床试验。
方法：使用来自年轻（20-35岁）和年龄较大（>80岁）的健康志愿者（每组n=10）的全血样本，用庆大霉素保护试验检查了GA水溶液对大肠杆菌吞噬作用的影响。用GA刺激每位志愿者的全血样品，并用CpG寡脱氧核苷酸（Toll样受体-9激动剂）刺激2小时作为对照，然后与大肠杆菌共孵育30分钟,然后用庆大霉素处理高达240分钟以杀死细胞外细菌。然后，全血细胞用蒸馏水裂解,和菌落形成单位通过定量平板计算。使用血液上清液进行细胞因子酶联免疫吸附测定以检测TNF-α和IL-6。
结果:测试的GA浓度(20mg/mL)不影响真核细胞的活力。来自年轻（p=0.008）和年长（p=0.004）健康志愿者的全血白细胞对大肠杆菌的吞噬作用在用GA刺激后增加了120.8％（年轻）和39.2％（年老）。相比之下,CpG仅刺激来自年轻志愿者的细胞的细菌吞噬作用（p=0.004）。用GA刺激全血增加了年轻志愿者（p=0.045）和老年志愿者（p=0.008）中大肠杆菌的细胞内杀伤作用，并诱导了从老年志愿者收集的全血中的TNF-α释放，而不是从年轻志愿者（p=0.008）。
结论：这些数据鼓励分离GA的活性化合物，并启动针对GA对细菌感染的预防作用的临床试验。
