Planta Medica International Open 2017; 4(S 01): S1-S202
DOI: 10.1055/s-0037-1608045
Lecture Session – Phytopharmacology & Extract Pharmacology I
Georg Thieme Verlag KG Stuttgart · New York

Switch to a motile lifestyle: Possible mechanism for antiadhesive effects of Orthosiphon stamineus Benth. aqueous extract against uropathogenic E. coli

S Srashar
1   Institute of Pharmaceutical Biology and Phytochemistry, Corrensstraße 48, D-48149, Muenster, Germany
,
A Hensel
1   Institute of Pharmaceutical Biology and Phytochemistry, Corrensstraße 48, D-48149, Muenster, Germany
,
S Brandt
1   Institute of Pharmaceutical Biology and Phytochemistry, Corrensstraße 48, D-48149, Muenster, Germany
,
C Stork
2   University of Münster, Institute of Hygiene, Robert-Koch-Str. 41, D-48149, Münster, Germany
,
U Dobrindt
2   University of Münster, Institute of Hygiene, Robert-Koch-Str. 41, D-48149, Münster, Germany
› Author Affiliations
Further Information

Publication History

Publication Date:
24 October 2017 (online)

 

Adhesion is an essential phase for uropathogenic E. coli (UPEC) to efficiently deploy on host cells. Hence, if bacteria-host cells attachment is inhibited in advance, infection is not productive. Therefore, targeting UPEC adhesion becomes an alternative approach to prevent UTIs. Interfering with adhesive surface structures such as pili, could potentially decrease the bacterial adhesion.

This study investigated the mechanism of the antiadhesive potential of a quantified aqueous extract (OWE) from the leaves of O. stamineus against UPEC, considering the effects of OWE on the adhesion-related genes.

OWE was quantified by UHPLC-UV on the content of rosmarinic acid, cichoric acid, and caffeic acid. Under in vitro conditions phenolic compounds depleted OWE (OWEøPC) exerts a dose-dependent antiadhesive activity against different UPEC strains. Furthermore, 3 and 5-day treatment of mice with OWE (750 mg/kg) after transurethral infection with UPEC CFT073 reduced the bacterial load in bladder and kidney, similar to norfloxacin [1].

Transcriptome analysis by next generation sequencing and cross-validation of these data by RT-PCR indicated that OWEøPC down-regulated the genes responsible for chaperone-mediated protein folding/unfolding and pilus assembly process (leading to decrease of porin activity) while flagellar assembly responsive genes were up-regulated as claimed by mRNA-Seq analysis (Fig. 1). So, on one hand OWE increases the motility of UPEC which makes it tougher for bacteria to attach to the host cells and on the other hand OWE disturbs the expression of relevant adhesive proteins. Therefore, it is concluded that OWE transforms the sessile lifestyle of bacteria to a motile one and therefore disables the bacterial surface attachment.

Zoom Image
Fig. 1: Relative gene expression of selected virulence factors (VF) from E. coli strain UTI89 determined by Illumina RNA-Seq. considering the effects of OWEøPC [2 mg/mL] on VFs regulations after 2h incubation in urine. All the expressions are related to untreated control adjusted at one.

[1] S. Sarshar, S. Brandt, M.R. Asadi Karam, M. Habibi, S. Bouzari, M. Lechtenberg, U. Dobrindt, X. Qin, F.M. Goycoolea, A. Hensel. Phytomedicine 2017; 28: 1 – 9