African Plant-Based Natural Products with Antivirulence Activities to the Rescue of Antibiotics

Abstract

The worldwide emergence of antibiotic-resistant bacteria and the thread of widespread superbug infections have led researchers to constantly look for novel effective antimicrobial agents. Within the past two decades, there has been an increase in studies attempting to discover molecules with innovative properties against pathogenic bacteria, notably by disrupting mechanisms of bacterial virulence and/or biofilm formation which are both regulated by the cell-to-cell communication mechanism called ‘quorum sensing’ (QS). Certainly, targeting the virulence of bacteria and their capacity to form biofilms, without affecting their viability, may contribute to reduce their pathogenicity, allowing sufficient time for an immune response to infection and a reduction in the use of antibiotics. African plants, through their huge biodiversity, present a considerable reservoir of secondary metabolites with a very broad spectrum of biological activities, a potential source of natural products targeting such non-microbicidal mechanisms. The present paper aims to provide an overview on two main aspects: (i) succinct presentation of bacterial virulence and biofilm formation as well as their entanglement through QS mechanisms and (ii) detailed reports on African plant extracts and isolated compounds with antivirulence properties against particular pathogenic bacteria.

Enhanced Activity and Sustained Release of Protocatechuic Acid, a Natural Antibacterial Agent, from Hybrid Nanoformulations with Zinc Oxide Nanoparticles

“…Absorbance was measured at 280 nm using the UV-vis technique (U-2900 spectrophotometer, Hitachi High-Technologies Corporation, Tokyo, Japan). Several measurements were performed for each sample, and the cumulative drug release of PCA from nanoformulations was calculated based on the following Equations ( 1) and (2): % of mass released at time t = (mass (t)/total mass of the drug in the nanoformulation) × 100 (1) cumulative % = mass (t − 1) + mass (t) for the current measurement (2) where mass (t) is the percentage release at the time of measurement and t − 1 is the percentage of the released drug at the previous timepoint. For kinetic model fitting, we analyzed the data for release profiles using pharmacokinetics software (KinetDS3, developed at Jagiellonian University, Krakow, at the Faculty of Pharmacy's Department of Pharmaceutical Technology and Biopharmaceutics).…”

“…As microorganisms exhibit an increasing and troubling resistance to drug therapies, including antibiotics, the search for new solutions has become urgent. The growing prevalence of resistant bacteria poses a global public health threat [ 1 ] as pathogens become adapted to the most frequently used antibiotics [ 2 ]. Novel strategies are needed, especially those that rely on alternative drug sources, including natural agents from plant-derived compounds [ 3 ].…”

Antibacterial Activity of Boswellia sacra Flueck. Oleoresin Extract against Porphyromonas gingivalis Periodontal Pathogen

“…This issue has forced researchers to constantly search for novel effective antimicrobial agents against different pathogenic bacteria. These antimicrobial agents could work via disrupting bacterial virulence such as biofilm formation [18]. Bacterial pathogenicity is defined as its ability to cause disease.…”

Novel Antiviral Activity of Ethyl 3-Hydroxyhexanoate Against Coxsackievirus B Infection

“…Suggesting that it is possible it has more than one molecular target. The wide variety of viral targets of EHX possibly showed its broad diverse antiviral activities, as plant-based natural products are considered as reservoir and prolific source of chemicals with a very broad spectrum of biological activities ( Pham et al, 2019 ; Mahavy et al, 2020 ). Furthermore, a study showed that plant-derived volatile compounds have short half-life and can be rapidly catabolized and degraded ( Oikawa and Lerdau, 2013 ).…”