School of Biomedical Sciences (M504), The University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia, 6009, Australia.
Division of Microbiology, PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, Western Australia, 6009, Australia.
Sci Rep. 2018 Oct 24;8(1):15735. doi: 10.1038/s41598-018-33954-2.
Clostridium difficile infection is a toxin-mediated disease of the colon. C. difficile virulence is primarily attributed to the production of toxin A and toxin B; thus this study was aimed to investigate the effect of a range of natural products on the production and activity of C. difficile toxins in vitro. Twenty-two natural products were investigated against four C. difficile strains. The activity of products against toxins was determined using Vero and HT-29 cells cytotoxicity and neutral red uptake assays. The indirect effect of products on toxin-mediated cytotoxicity was determined using the same cell lines. The effect of seven products on toxin production by C. difficile was determined using ELISA. Zingerone (0.3 mg/ml) protected both cell lines from C. difficile cytopathic effects, confirmed by the neutral red uptake assay (P < 0.05). Three Leptospermum honeys (4% w/v), fresh onion bulb extract (12.5% v/v) and trans-cinnamaldehyde (0.005% v/v) all reduced toxin production and activity significantly (P ≤ 0.023). Garlic clove powder (4.7 mg/ml) only reduced toxin activity (P ≤ 0.047). Overall, several natural products had activity against C. difficile toxins in vitro encouraging further investigation against C. difficile toxins in vivo.
艰难梭菌感染是一种结肠毒素介导的疾病。艰难梭菌的毒力主要归因于毒素 A 和毒素 B 的产生；因此，本研究旨在研究一系列天然产物对体外艰难梭菌毒素产生和活性的影响。对 22 种天然产物对 4 株艰难梭菌的活性进行了研究。使用 Vero 和 HT-29 细胞细胞毒性和中性红摄取测定法测定产物对毒素的活性。使用相同的细胞系测定产物对毒素介导的细胞毒性的间接影响。使用 ELISA 测定 7 种产物对艰难梭菌毒素产生的影响。荜澄茄素（0.3mg/ml）通过中性红摄取测定法（P<0.05）证实，可保护两种细胞系免受艰难梭菌细胞病变效应的影响。三种 Leptospermum 蜂蜜（4%w/v）、新鲜洋葱鳞茎提取物（12.5%v/v）和反式肉桂醛（0.005%v/v）均显著降低毒素的产生和活性（P≤0.023）。大蒜瓣粉（4.7mg/ml）仅降低毒素活性（P≤0.047）。总的来说，几种天然产物对体外艰难梭菌毒素具有活性，这鼓励进一步对体内艰难梭菌毒素进行研究。
