Antibiofilm and antifungal activities of medium-chain fatty acids against Candida albicans via mimicking of the quorum-sensing molecule farnesol

Jin-Hyung Lee,† Yong-Guy Kim,† Sagar Kiran Khadke and Jintae Lee* School of Chemical Engineering, Yeungnam University, Gyeongsan, Korea.

Summary

       Candida biofilms are tolerant to conventional antifungal therapeutics and the host immune system. The transition of yeast cells to hyphae is considered a key step in C. albicans biofilm development, and this transition is inhibited by the quorum-sensing molecule farnesol. We hypothesized that fatty acids mimicking farnesol might influence hyphal and biofilm formation by C. albicans. Among 31 saturated and unsaturated fatty acids, six medium-chain saturated fatty acids, that is, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid and lauric acid, effectively inhibited C. albicans biofilm formation by more than 75% at 2 µg ml¯1 with MICs in the range 100–200 µg ml¯1 . These six fatty acids at 2 µg ml¯1 and farnesol at 100 µg ml¯1 inhibited hyphal growth and cell aggregation. The addition of fatty acids to C. albicans cultures decreased the productions of farnesol and sterols. Furthermore, downregulation of several hyphal and biofilm-related genes caused by heptanoic or nonanoic acid closely resembled the changes caused by farnesol. In addition, nonanoic acid, the most effective compound diminished C. albicans virulence in a Caenorhabditis elegans model. Our results suggest that mediumchain fatty acids inhibit more effectively hyphal growth and biofilm formation than farnesol.

       Received 2 July, 2020; revised 29 October, 2020; accepted 30 October, 2020. *For correspondence: E-mail: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。. Tel. +82-53-810- 2533; Fax +82-53-810-4631. † These authors contributed equally to this work. Microbial Biotechnology (2021) 14(4), 1353–1366 doi:10.1111/1751-7915.13710

Funding information

       This research was supported by grants from the Basic Science Research Program through the NRF funded by the Ministry of Education (2018R1D1A3B07040699 to J.-H. Lee, 2019R1C1C1008329 to Y.-G. Kim), by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through Innovational Food Technology Development Program, funded by the Ministry of Agriculture, Food and Rural Affairs (MAFRA) (119034-3), and by a grant from the Priority Research Centers Program through the NRF funded by the Ministry of Education (2014R1A6A1031189).

Assessment of Antibiofilm Potencies of Nervonic and Oleic Acidagainst Acinetobacter baumannii Using In Vitroand Computational Approaches

SagarKiranKhadke ,Jin-HyungLee,Yong-GuyKim,VinitRajandJintaeLee*

School of Chemical Engineering,Yeungnam University,Gyeongsan38541,Korea;该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(S.K.K.); 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(J.-H.L.);该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(Y.-G.K.);该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(V.R.)">该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(J.-H.L.);该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(Y.-G.K.);该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。(V.R.) *Correspondence:该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。;Tel.:+82-53-810-2533;Fax:+82-53-810-4631

Citation: Khadke, S.K.; Lee, J.-H.; Kim, Y.-G.; Raj, V.; Lee, J. Assessment of Antibiofilm Potencies of Nervonic and Oleic Acid against Acinetobacter baumannii Using In Vitro and Computational Approaches. Biomedicines 2021, 9, 1133. https://

doi.org/10.3390/biomedicines9091133

Academic Editor: Leonardo Caputo

Received: 19 July 2021

Accepted: 29 August 2021

Published: 1 September 2021

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/4.0/).

Abstract: Acinetobacter baumannii is a nosocomial pathogen, and its biofilms are tolerant to desiccation, nutrient starvation, and antimicrobial treatment on biotic and abiotic surfaces, tissues, and medical devices. Biofilm formation by A. baumannii is triggered by a quorum sensing cascade, and we hypothesized that fatty acids might inhibit its biofilm formation by interfering with quorum sensing. Initially, we investigated the antibiofilm activities of 24 fatty acids against A. baumannii ATCC 17978 and two clinical isolates. Among these fatty acids, two unsaturated fatty acids, nervonic and oleic acid, at 20 µg/mL significantly inhibited A. baumannii biofilm formation without affecting its planktonic cell growth (MICs were >500 µg/mL) and markedly decreased the motility of A. baumannii but had no toxic effect on the nematode Caenorhabditis elegans. Interestingly, molecular dynamic simulations showed that both fatty acids bind to the quorum sensing acyl homoserine lactone synthase (AbaI), and decent conformational stabilities of interactions between the fatty acids and AbaI were exhibited. Our results demonstrate that nervonic and oleic acid inhibit biofilm formation by A. baumannii strains and may be used as lead molecules for the control of persistent A. baumannii infections.

Keywords: Acinetobacter baumannii; biofilm formation; AbaI; computational studies; fatty acid; nervonic acid; virulence; quorum sensing; antibiofilm agents.

The pharmacology and clinical properties of Kalopanax pictus

Tae Kyung Hyun1 and Ju-Sung Kim2*

1Institut fuer Pflanzenwissenschaften, Schubertstr. 51, A-8010 Graz, Austria. 2Oriental Bio-herb Research Institute, Kangwon National University, Chuncheon, 200-701, Korea. Accepted 17 August, 2009

Kalopanax pictus is known as Castor-Aralia or Prickly Castor-oil tree. K. pictus extracts have been used for dietary health supplements and are an important area in drug development with numerous pharmacological functions in East Asia; however, their pharmacological functions have not been introduced in Western countries. This paper briefly reviews the most relevant experimental data on the pharmacological actions of K. pictus to overcome the lack of information on this plant. K. pictus extracts have proved to be effective in the treatment of inflammation and were shown to have a number of pharmaceutically relevant benefits that include anti-rheumatoidal, hepatoprotective, anti-diabetic, anti-cancer effects, etc. There are a few known active pharmacological components such as kalopanaxsaponin A and I. Although the molecular mechanisms of most of the effects are not fully understood, major mechanisms seem to involve the interplay between active components and signaling mediated by phosphorylation events during stress adaptation.

Key words: Kalopanax pictus, araliaceae, Kalopanaxsaponins A, anti-inflammatory, anti-rheumatoidal activity, anti-diabetic, hepatoprotective effect.

A comprehensive review of the benefts of Taraxacum ofcinale on human health

Agnese Di Napoli* and Pietro Zucchetti

Abstract

Background: Taraxacum officinale (G.H. Weber ex Wiggers), commonly known as dandelion, is a herbaceous plant native to North America, Europe and Asia. This plant has been used for health purposes since ancient times. The phytochemicals present in different parts of the plant are responsible for its medicinal properties. In this review, we describe the main health properties of Taraxacum officinale.

Main body of the abstract: We searched for the main medicinal properties of Taraxacum officinale in the scientific literature, using the PubMed database. We selected 54 studies and we described twelve therapeutic properties, which are reported in previous studies. These properties are diuretic, hepatoprotective, anticolitis, immunoprotective, antiviral, antifungal, antibacterial, antiarthritic, antidiabetic, antiobesity, antioxidant and anticancer effects. We also found that the most frequently reported therapeutic effects include hepatoprotective, antioxidant and anticancer activities.

Short conclusion: In this review, we describe the medicinal properties of Taraxacum officinale reported in previous studies. Antioxidant, hepatoprotective and anticancer effects are mostly found in the scientific literature.

Keywords: Taraxacum officinale, Dandelion, Medicinal properties, Hepatoprotective, Antioxidant, Anticancer.

Using Telemedicine to Improve Outcomes in Diabetes—An Emerging Technology

David C. Klonoff, M.D., FACP

Author Affiliation: Mills-Peninsula Health Services, San Mateo, California

Abbreviation: (A1C) hemoglobin A1c

Corresponding Author: David C. Klonoff, M.D., FACP, Mills-Peninsula Health Services, 100 South San Mateo Drive, Room 5147, San Mateo, CA 94401; email address 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 J Diabetes Sci Technol 2009;3(4):624-628

Inhibition of polymicrobial biofilm formation by saw palmetto oil, lauric acid and myristic acid

Yong-Guy Kim† Jin-Hyung Lee† Sunyoung Park, Sanghun Kim and Jintae Lee * School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Korea.

Received 8 March, 2021; revised 22 May, 2021; accepted 23 May,*For correspondence. E-mail 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。; Tel. (+82) 53 810 2533; Fax (+82) 53 810 4631. †† Y.-G.K. and J.-H.L. contributed equally to this work. Microbial Biotechnology (2022) 15(2), 590–602

doi:10.1111/1751-7915.13864

Funding information

This research was supported by grants from the Basic Science Research Program through the NRF funded by the Ministry of Education (2021R1I1A3A04037486 to J.-H. Lee, 2019R1C1C1008329 to Y.-G. Kim), the NRF grant funded by the Korea government (MSIT) (No. 2021R1A2C1008368 to J. Lee), and by a grant from the Priority Research Centers Program through the NRF funded by the Ministry of Education (2014R1A6A1031189).

Summary

       Biofilms are communities of bacteria, fungi or yeasts that form on diverse biotic or abiotic surfaces, and play important roles in pathogenesis and drug resistance. A generic saw palmetto oil inhibited biofilm formation by Staphylococcus aureus, Escherichia coli O157:H7 and fungal Candida albicans without affecting their planktonic cell growth. Two main components of the oil, lauric acid and myristic acid, are responsible for this antibiofilm activity. Their antibiofilm activities were observed in dual-species biofilms as well as three-species biofilms of S. aureus, E. coli O157:H7 and C. albicans. Transcriptomic analysis showed that lauric acid and myristic acid repressed the expressions of haemolysin genes (hla and hld) in S. aureus, several biofilm-related genes (csgAB, fimH and flhD) in E. coli and hypha cell wall gene HWP1 in C. albicans, which supported biofilm inhibition. Also, saw palmetto oil, lauric acid and myristic acid reduced virulence of three microbes in a nematode infection model and exhibited minimal cytotoxicity. Furthermore, combinatorial treatment of fatty acids and antibiotics showed synergistic antibacterial efficacy against S. aureus and E. coli O157:H7. These results demonstrate that saw palmetto oil and its main fatty acids might be useful for controlling bacterial infections as well as multispecies biofilms.