Nohynek Liisa J, Alakomi Hanna-Leena, Kähkönen Marja P, Heinonen Marina, Helander Ilkka M, Oksman-Caldentey Kirsi-Marja, Puupponen-Pimiä Riitta H
VTT Biotechnology, Tietotie 2, VTT, Finland.
Nutr Cancer. 2006;54(1):18-32. doi: 10.1207/s15327914nc5401_4.
Antimicrobial activity and mechanisms of phenolic extracts of 12 Nordic berries were studied against selected human pathogenic microbes. The most sensitive bacteria on berry phenolics were Helicobacter pylori and Bacillus cereus. Campylobacter jejuni and Candida albicans were inhibited only with phenolic extracts of cloudberry, raspberry, and strawberry, which all were rich in ellagitannins. Cloudberry extract gave strong microbicidic effects on the basis of plate count with all studied strains. However, fluorescence staining of liquid cultures of virulent Salmonella showed viable cells not detectable by plate count adhering to cloudberry extract, whereas Staphylococcus aureus cells adhered to berry extracts were dead on the basis of their fluorescence and plate count. Phenolic extracts of cloudberry and raspberry disintegrated the outer membrane of examined Salmonella strains as indicated by 1-N-phenylnaphthylamine (NPN) uptake increase and analysis of liberation of [14C]galactose- lipopolysaccharide. Gallic acid effectively permeabilized the tested Salmonella strains, and significant increase in the NPN uptake was recorded. The stability of berry phenolics and their antimicrobial activity in berries stored frozen for a year were examined using Escherichia coli and nonvirulent Salmonella enterica sv. Typhimurium. The amount of phenolic compounds decreased in all berries, but their antimicrobial activity was not influenced accordingly. Cloudberry, in particular, showed constantly strong antimicrobial activity during the storage.
研究了12种北欧浆果酚类提取物对选定的人类致病微生物的抗菌活性及其作用机制。对浆果酚类最敏感的细菌是幽门螺杆菌和蜡样芽孢杆菌。空肠弯曲菌和白色念珠菌仅被富含鞣花单宁的云莓、覆盆子和草莓的酚类提取物抑制。基于平板计数，云莓提取物对所有研究菌株均有很强的杀菌作用。然而，对有毒力的沙门氏菌液体培养物进行荧光染色显示，平板计数检测不到的活细胞附着在云莓提取物上，而附着在浆果提取物上的金黄色葡萄球菌细胞根据其荧光和平板计数显示已死亡。1-N-苯基萘胺（NPN）摄取增加以及[14C]半乳糖-脂多糖释放分析表明，云莓和覆盆子的酚类提取物破坏了受试沙门氏菌菌株的外膜。没食子酸有效地使受试沙门氏菌菌株通透性增加，NPN摄取量显著增加。使用大肠杆菌和无毒的肠炎沙门氏菌鼠伤寒血清型，检测了冷冻保存一年的浆果中酚类物质的稳定性及其抗菌活性。所有浆果中酚类化合物的含量均有所下降，但其抗菌活性并未因此受到影响。特别是云莓，在储存期间始终表现出很强的抗菌活性。
