Cecropin B

Cecropin B is an antimicrobial peptide that exhibits potent antibacterial activity against Escherichia coli and a broad spectrum of Gram-negative bacteria^[1], thereby showing wide-spectrum antimicrobial properties^[2]. Its primary mechanism of action involves binding to and acting upon negatively charged bacterial cell membranes, altering membrane potential, inducing membrane damage, and facilitating the permeation of macromolecules such as proteins. This process disrupts cellular morphology and membrane integrity, ultimately leading to cell death^[3].

In vitro, treatment of porcine hepatocytes with Cecropin B (0-500ng/mL) for 3-24 hours significantly inhibited the expression of cytochrome P450 family 3 subfamily A polypeptide 29 (CYP3A29) and pregnane X receptor (PXR). This inhibitory effect was both concentration- and time-dependent in the short term^[4].

In vivo, topical application of Cecropin B (100mg/L/day for 4 days) significantly inhibited Pseudomonas aeruginosa infection in a mouse wound model and reduced mortality^[5]. In a rat model of septic shock, intraperitoneal administration of Cecropin B (1mg/kg), either alone or in combination with piperacillin (120mg/kg) for 72h, demonstrated anti-endotoxin activity and markedly reduced plasma levels of endotoxin and tumor necrosis factor alpha (TNF-alpha)^[6].

References:
[1]Steiner H, Hultmark D, Engström A, Bennich H, Boman HG. Sequence and specificity of two antibacterial proteins involved in insect immunity. Nature. 1981 Jul 16;292(5820):246-8.
[2]Amso Z , Hayouka Z . Antimicrobial random peptide cocktails: a new approach to fight pathogenic bacteria. Chem Commun (Camb). 2019 Feb 12;55(14):2007-2014.
[3]Lei J, Sun L, Huang S, Zhu C, Li P, He J, Mackey V, Coy DH, He Q. The antimicrobial peptides and their potential clinical applications. Am J Transl Res. 2019 Jul 15;11(7):3919-3931.
[4]Zhou X, Li X, Wang X, Jin X, Shi D, Wang J, Bi D. Cecropin B Represses CYP3A29 Expression through Activation of the TLR2/4-NF-κB/PXR Signaling Pathway. Sci Rep. 2016 Jun 14;6:27876.
[5] Ren HT, Han CM, Zhang R, Xu ZJ, Meng ZQ, Weng HB, Niu BL. The antibacterial effect of cecropin B on pseudomonas aeruginosa infection of wounds in mice]. Zhonghua Shao Shang Za Zhi. 2006 Dec;22(6):445-7. Chinese.
[6] Ghiselli R, Giacometti A, Cirioni O, Mocchegiani F, Orlando F, D'Amato G, Sisti V, Scalise G, Saba V. Cecropin B enhances betalactams activities in experimental rat models of gram-negative septic shock. Ann Surg. 2004 Feb;239(2):251-6.

Cecropin B是一种多肽抗菌素，对大肠杆菌及其他多种革兰氏阴性菌具有强效抗菌活性^[1]，具有广谱的抗菌活性^[2]。主要作用机制是其能结合并作用于带负电荷的细菌细胞膜，改变膜电位，诱导细胞膜损伤，导致蛋白质等大分子物质渗透，破坏细胞形态和膜结构，最终引起细胞死亡^[3]。

在体外，在体外，Cecropin B（0-500ng/mL）处理猪肝细胞细胞3-24h，显著抑制了细胞色素P450家族3亚家族A多肽29（CYP3A29）与孕烷 X 受体（PXR）的表达，且短期内其抑制效应呈现浓度和时间依赖性^[4]。

在体内，Cecropin B（100mg/L/day for 4 days）通过湿敷治疗铜绿假单胞菌感染模型小鼠4天，对铜绿假单胞菌感染创面具有显著抗菌作用，并降低了小鼠的死亡率^[5]。Cecropin B（1mg/kg ）单独或与哌拉西林（120mg/kg ）联合通过腹腔注射治疗脓毒症休克模型大鼠72h，显示出抗内毒素活性，并使血浆内毒素和肿瘤坏死因子-α（TNF-α）水平降至最低^[6]。