Aim

Due to the significant increase in the antimicrobial resistance of Acinetobacter baumannii (A. baumannii), new drugs to block the progression of infection are strongly needed. Epigallocatechin-3-gallate (EGCG), a major component of green tea, has exhibited potential activity against A. baumannii in vitro. The aim of this study was to determine if EGCG could be used for pretreating stress-related effects, liver damage, and immune dysfunction caused by A. baumannii infection in vivo.

Methods

Levels of stress hormones, oxidative stress, liver damage, and immune components were analyzed in a murine infection model in which the mice were pretreated with EGCG for one week then intranasally inoculated with A. baumannii. The mice were restrained for 12 h to promote infection because A. baumannii is an opportunistic pathogen. The pretreatment efficacy of EGCG against A. baumannii in mice was assessed for 24 h after the bacterial infection.

Results

Restraint stress strengthened the damage from the A. baumannii infection. Pretreatment with EGCG in the murine pneumonia model markedly reduced stress hormones, oxidative metabolites, and proinflammatory cytokine production. EGCG also increased the immune function by increasing the levels of sIgA, T cells and neutrophils after infection. Moreover, pretreatment with EGCG significantly decreased the liver damage by inhibiting the levels of transaminases, oxidative stress metabolites, and cytokines, while maintaining the normal activity of CYP450 enzymes in the liver.

Conclusion

EGCG was efficacious as a preventative treatment for the damage seen in an experimental model of A. baumannii infection.

中文翻译：

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表没食子儿茶素-3-没食子酸酯可减轻鲍曼不动杆菌负荷应激小鼠的肝脏和免疫系统损害

目标

由于鲍曼不动杆菌（鲍曼不动杆菌）的抗微生物性显着增加，因此强烈需要阻断感染进展的新药物。Epigallocatechin-3-gallate（EGCG）是绿茶的主要成分，在体外对鲍曼不动杆菌具有潜在的活性。这项研究的目的是确定EGCG是否可用于预防体内鲍曼不动杆菌感染引起的应激相关效应，肝脏损害和免疫功能障碍。

方法

在鼠感染模型中分析了应激激素，氧化应激，肝损伤和免疫成分的水平，在该模型中，小鼠用EGCG预处理了一周，然后鼻内接种了鲍曼不动杆菌。因为鲍曼不动杆菌是机会病原体，所以小鼠被限制了12小时以促进感染。在细菌感染后24小时，评估了EGCG对鲍曼不动杆菌的预处理效果。

结果

约束压力增强了鲍曼不动杆菌感染的损害。在鼠型肺炎模型中用EGCG预处理可显着减少应激激素，氧化代谢产物和促炎细胞因子的产生。EGCG还通过增加感染后sIgA，T细胞和中性粒细胞的水平来增强免疫功能。此外，EGCG预处理可通过抑制转氨酶，氧化应激代谢产物和细胞因子的水平显着降低肝脏损伤，同时保持肝脏中CYP450酶的正常活性。

结论

EGCG对于预防鲍曼不动杆菌感染的实验模型中的损伤是有效的。