Freitas S F, Shinohara L, Sforcin J M, Guimarães S
Department of Parasitology, Biosciences Institute, IB-UNESP, Botucatu, SP, Brazil.
Phytomedicine. 2006 Feb;13(3):170-5. doi: 10.1016/j.phymed.2004.07.008. Epub 2005 Jun 24.
In order to improve the current chemotherapy of Giardia infection, potential antigiardial agents have been screened, including natural products. Propolis, a resinous hive product collected by bees, has attracted attention as a useful and popular substance with several therapeutic activities. The present study was carried out aiming to evaluate the in vitro effects of an ethanolic extract of propolis on the growth and adherence of Giardia duodenalis trophozoites. Propolis inhibited the growth of trophozoites and the level of inhibition varied according to the extract concentration and incubation times. The highest reduction of parasite growth was observed in cultures exposed to 125, 250 and 500 microg/ml of propolis, in all incubation periods (24, 48, 72 and 96 h). Growth reduction by 50% was observed in 125 microg/ml propolis-treated cultures, while the concentrations of 250 and 500 microg/ml were able to inhibit growth by more than 60%. Propolis also inhibited parasite adherence and all assayed propolis concentrations promoted the detachment of trophozoites. Light microscope observations revealed changes of the pear-shaped aspect of the cell and reduction of flagellar beating frequency in the great part of the trophozoites. Our results hold the perspective for the utilization of propolis as an antigiardial agent.
为了改进目前对贾第虫感染的化疗方法，人们筛选了包括天然产物在内的潜在抗贾第虫药物。蜂胶是蜜蜂采集的一种树脂状蜂巢产物，作为一种具有多种治疗活性的有用且广受欢迎的物质而受到关注。本研究旨在评估蜂胶乙醇提取物对十二指肠贾第虫滋养体生长和黏附的体外作用。蜂胶抑制了滋养体的生长，抑制程度随提取物浓度和孵育时间而变化。在所有孵育期（24、48、72和96小时），在暴露于125、250和500微克/毫升蜂胶的培养物中观察到寄生虫生长的最大降幅。在经125微克/毫升蜂胶处理的培养物中观察到生长降低50%，而250和500微克/毫升的浓度能够抑制生长超过60%。蜂胶还抑制寄生虫黏附，所有测定的蜂胶浓度都促使滋养体脱离。光学显微镜观察显示，大部分滋养体细胞的梨形外观发生变化，鞭毛摆动频率降低。我们的结果为将蜂胶用作抗贾第虫药物提供了前景。
