Using the Chinese herb Scutellaria barbata against extensively drug-resistant Acinetobacter baumannii infections: in vitro and in vivo studies

Abstract

BackgroundNo animal model studies have been conducted in which the efficacy of herbal compounds has been tested against multidrug-resistant Acinetobacter baumannii infections. Very few antibiotics are available for the treatment of pulmonary infections caused by extensively drug-resistant Acinetobacter baumannii (XDRAB). To find alternative treatments, traditional Chinese herbs were screened for their antimicrobial potential.MethodsThe present study screened 30 herbs that are traditionally used in Taiwan and that are commonly prescribed for heat clearing and detoxification. The herbs with antibacterial activities were analysed by disc diffusion assays, time-kill assays and a murine lung infection model.ResultsOf the 30 herbs tested, only Scutellaria barbata demonstrated 100% in vitro activity against XDRAB. Furthermore, we compared the antibacterial effect of the S. barbata extract with that of colistin, and the S. barbata extract showed better antibacterial effect. In the XDRAB pneumonia murine model, we compared the antimicrobial effects of the orally administered S. barbata extract (200 mg/kg, every 24 h), the intratracheally administered colistin (75,000 U/kg, every 12 h), and the control group. The bacterial load in the lungs of the treatment group that received the oral S. barbata extract showed a significant decrease in comparison to that in the lungs of the control group. In addition, histopathological examinations also revealed better resolution of perivascular, peribronchial, and alveolar inflammation in the oral S. barbata extract-treated group.ConclusionsOur in vitro and in vivo data from the animal model support the use of S. barbata as an alternate drug to treat XDRAB pulmonary infections. However, detailed animal studies and clinical trials are necessary to establish the clinical utility of S. barbata in treating XDRAB pulmonary infections.

Pimenta Oil as a Potential Treatment for Acinetobacter baumannii Wound Infection: In Vitro and In Vivo Bioassays in Relation to Its Chemical Composition

“…This study is the first to report the in vivo antimicrobial effect of P. dioica and P. racemosa E.Os in an A. baumannii wound infection model. In the same context, Tsai et al [ 41 ] screened 30 Chinese herbs for antimicrobial effect against extensively drug-resistant A. baumannii isolates. Where, only Scutellaria barbata aqueous extract showed the highest activity in vitro and is likely to be mediated by polar type compounds in contrast to lipophilic nature of E.O reported herein and suggesting that different chemically based metabolites could evoke antimicrobial action against A. baumannii .…”

Comparison of the Gut Microbiota Between Pulsatilla Decoction and Levofloxacin Hydrochloride Therapy on Escherichia coli Infection

“…In fact, Chinese herbal medicine compound has no direct antibacterial effect in vitro but enhances the antibacterial effect in vivo by mobilizing innate immunity. As report showed, among 30 Chinese herbs, only Scutellaria barbata had the 100% antibacterial activity in vitro (Tsai et al, 2018 ). Actually, Chinese herbs, such as Astragali Radix are benefit for intestinal bacterial conversion (Zhou et al, 2012 ).…”

Effect of the Chinese Medicine YangZheng XiaoJi on Reducing Fatigue in Mice with Orthotopic Transplantation of Colon Cancer

“…Scutellaria barbata, a traditional anticancer Chinese medicine, has been found to have the additional effect of anti-inflammation and anti-infection in recent years. Diterpenoid alkaloids and 6-methoxynaringenin in the Scutellaria barbata extracts had the strongest effect on downregulating the secretion of NO, PE2, IL-6, IL-1 β induced by LPS and P-JNK signaling pathway activation [42–44]. Moreover, the water extracts of Bittersweet herb and Herba artemisiae scopariae can alleviate inflammation by inhibition of NF- κ B pathway that reduces the generation of proinflammatory cytokines like IL-1 β and IL-6 [45–47].…”