2. Academic Validation
  3. Physcion, a novel anthraquinone derivative against Chlamydia psittaci infection

Physcion, a novel anthraquinone derivative against Chlamydia psittaci infection

  • Vet Microbiol. 2023 Apr:279:109664. doi: 10.1016/j.vetmic.2023.109664.
Xinyi Liu 1,  Huilong Hu 1,  Jiaqi Liu 1,  Jiaqi Chen 1,  Jun Chu 2,  He Cheng 3
Affiliations

Affiliations

  • 1 National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine, China Agricultural University, Beijing, China.
  • 2 Animal Science and Technology College, Beijing University of Agriculture, Beijing, China.
  • 3 National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine, China Agricultural University, Beijing, China. Electronic address: hecheng@cau.edu.cn.
PMID: 36716634 DOI: 10.1016/j.vetmic.2023.109664
Abstract

Physcion, a natural anthraquinone derivative, has been reported to exert remarkable Antibacterial activities against Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa. However, it is not fully illustrated as anti-Chlamydia substance. In the present study, minimum inhibitory concentration(MIC)values for physcion against Chlamydia psittaci(C.psittaci) 6BC, C.psittaci SBL and C.psittaci HJ were 128 μg/mL,256 μg/mL and 128 μg/mL while minimum bactericidal concentration (MBC) values were 256 μg/mL,512 μg/mL and 256 μg/mL,respectively. Moreover, Chlamydial adhesion to Hela 229 cells was blocked in a dose-dependent manner and RB-to-EB differentiation was inhibited by physcion from 28 to 48 hpi.Post treatment,upregulation of LC3-II was in a dose-dependent manner, indicating physcion activated Autophagy and Bacterial clearance.To validate clinical efficacy,49 SPF chickens aged 21days were divided into 5 groups and infected intra-laryngeally with 0.2 mL of 1 × 107 IFU/mL C.psittaci 6 BCE.Three days later, birds received orally with serial doses of physcion (4 mg/kg to 9 mg/kg), or 3 mg/kg of doxycycline for 6 days.Chickens with difficulty in breathing were alleviated significantly with increasing concentrations of physicon.Postmortem,lesions of air sacs were reduced significantly in a dose-dependent manner.More importantly,birds with 9 mg/kg of physcion could alleviate lesions of air sacs and lungs, and reduce Bacterial loads in spleens, which was comparable to doxycycline treatment. Based on above evidences, physcion is a promising cost-effective natural drug by blocking Chlamydial adhesions to host cells, RB-to-EB differentiation and activating bacterial Autophagy and it will be a good alternative to doxycycline combating virulent C.psittaci Infection, contributing to eradication of Chlamydial transmission from Animals to human beings.

Keywords

Autophagy; Chlamydia psittaci; Efficacy; Elementary body; Physcion; Reticular body.

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