Anthony J-P, Fyfe L, Stewart D, McDougall G J, Smith H V
Dietetics, Nutrition and Biological Sciences, Queen Margaret University, Clerwood Terrace, Edinburgh EH12 8TS, UK.
Methods. 2007 Aug;42(4):339-48. doi: 10.1016/j.ymeth.2007.02.011.
The protozoan parasites Giardia duodenalis and Cryptosporidium parvum are common causes of diarrhoea, worldwide. Effective drug treatment is available for G. duodenalis, but with anecdotal evidence of resistance or reduced compliance. There is no effective specific chemotherapeutic intervention for Cryptosporidium. Recently, there has been renewed interest in the antimicrobial properties of berries and their phenolic compounds but little work has been done on their antiparasitic actions. The effect of various preparations of blueberry (Vaccinium myrtillus) extract on G. duodenalis trophozoites and C. parvum oocysts were investigated. Pressed blueberry extract, a polyphenolic-rich blueberry extract, and a commercially produced blueberry drink (Bouvrage) all demonstrated antigiardial activity. The polyphenol-rich blueberry extract reduced trophozoite viability in a dose dependent manner. At 167 microgml(-1), this extract performed as well as all dilutions of pressed blueberry extract and the Bouvrage beverage (9.6+/-2.8% live trophozoites remaining after 24h incubation). The lowest dilution of blueberry extract tested (12.5% v/v) contained >167 microgml(-1) of polyphenolic compounds suggesting that polyphenols are responsible for the reduced survival of G. duodenalis trophozoites. The pressed blueberry extract, Bouvrage beverage and the polyphenolic-rich blueberry extract increased the spontaneous excystation of C. parvum oocysts at 37 degrees C, compared to controls, but only at a dilution of 50% Bouvrage beverage, equivalent to 213 microgml(-1) gallic acid equivalents in the polyphenolic-rich blueberry extract. Above this level, spontaneous excystation is decreased. We conclude that water soluble extracts of blueberries can kill G. duodenalis trophozoites and modify the morphology of G. duodenalis and C. parvum.
原生动物寄生虫十二指肠贾第虫和微小隐孢子虫是全球腹泻的常见病因。对于十二指肠贾第虫有有效的药物治疗方法，但有抗药性或依从性降低的传闻证据。对于隐孢子虫没有有效的特异性化疗干预措施。最近，人们对浆果及其酚类化合物的抗菌特性重新产生了兴趣，但关于它们的抗寄生虫作用的研究很少。研究了蓝莓（欧洲越橘）提取物的各种制剂对十二指肠贾第虫滋养体和微小隐孢子虫卵囊的影响。压榨蓝莓提取物、富含多酚的蓝莓提取物和市售蓝莓饮料（布瓦拉热）均表现出抗贾第虫活性。富含多酚的蓝莓提取物以剂量依赖的方式降低了滋养体的活力。在167微克/毫升时，该提取物的效果与压榨蓝莓提取物和布瓦拉热饮料的所有稀释液相同（孵育24小时后剩余9.6±2.8%的活滋养体）。测试的蓝莓提取物最低稀释度（12.5%体积/体积）含有>167微克/毫升的多酚化合物，这表明多酚是导致十二指肠贾第虫滋养体存活率降低的原因。与对照组相比，压榨蓝莓提取物、布瓦拉热饮料和富含多酚的蓝莓提取物在37℃时增加了微小隐孢子虫卵囊的自发脱囊，但仅在50%布瓦拉热饮料的稀释度下，相当于富含多酚的蓝莓提取物中213微克/毫升没食子酸当量。高于此水平，自发脱囊减少。我们得出结论，蓝莓的水溶性提取物可以杀死十二指肠贾第虫滋养体并改变十二指肠贾第虫和微小隐孢子虫的形态。
