Antimicrobial activity against Helicobacter pylori strains and antioxidant properties of blackberry leaves (Rubus ulmifolius) and isolated compounds

Rubus spp. (Rosaceae) provide extracts used in traditional medicine as antimicrobial, anticonvulsant, muscle relaxant and radical scavenging agents. Resistance to antibiotics used to treat Helicobacter pylori infection as well as their poor availability in developing countries prompted us to test the antimicrobial activity of Rubus ulmifolius leaves and isolated polyphenols against two H. pylori strains with different virulence (CagA+ strain 10K and CagA− strain G21). The antioxidant activity (TEAC values) of the tested compounds ranged from 4.88 (gallic acid) to 1.60 (kaempferol), whilst the leaf extract gave a value of 0.12. All the isolated polyphenols as well as the leaf extract showed antibacterial activity against both of the H. pylori strains. The minimum bactericidal concentrations (MBCs) of the extract for H. pylori strains G21 and 10K, respectively, were 1200ug/mL and 1500ug/mL after 24 h of exposure and 134ug/mL and 270ug/mL after 48 h exposure. Ellagic acid showed very low MBC values towards both of the H. pylori strains after 48 h (2ug/mL and 10ug/mL for strains G21 and 10K, respectively) and kaempferol toward G21 strain (MBC = 6ug/mL). A relationship between antimicrobial activity and antioxidant capacity was found only for H. pylori strain G21 CagA− strain.

蔷薇科植物悬液具有抗菌、抗惊厥、肌肉松弛和自由基清除等传统药用成分。对于用于治疗幽门螺杆菌感染的抗生素的耐药性以及它们在发展中国家的缺乏，促使我们测试了悬钩子叶和分离出的多酚对两种不同毒力的幽门螺杆菌菌株(CagA+菌株10K和CagA−菌株G21)的抗菌活性。化合物的抗氧化活性(TEAC值)为4.88(没食子酸)- 1.60(山奈酚)，而叶提取物的抗氧化活性为0.12。所得多酚和叶提取物均对两种幽门螺杆菌均有抑菌活性。对幽门螺杆菌G21株和10K株的最低杀菌浓度(MBCs)在24 h后分别为1200ug/mL和1500ug/mL，在48 h后分别为134ug/mL和270ug/mL。48 h后，鞣花酸对两株幽门螺杆菌的MBC值均很低(G21株为2ug/mL, 10K株为10ug/mL)，山奈酚对G21株为6ug/mL。只有幽门螺杆菌菌株G21 CagA−具有抑菌活性和抗氧化能力的关系。

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http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM19386474