General overview of phenolics from plant to laboratory, good antibacterials or not

Abstract

The emergence and rapid development of seriously drug-resistant pathogens have created the greatest danger to public health and made the treatment of infectious diseases ineffective; to control the antibiotic-resistant microbes, the discovery of new effective antibacterials with new mechanisms of action against bacteria remains an urgent task to control the bacterial resistance. The paucity of infections in wild plants supports the role of innate defense system of plants. Many researchers nominate the natural extracts to act against bacterial resistance mechanisms, and the majority of them have now been focused on the combination of plant extracts and antibiotics to define the availability of resistance modification agents. Only very few numbers of natural products are successful to reach experiments circle beyond the in vitro assays. Phenols and phenolic acids could serve as good candidates to the natural antibacterial arsenal. The pyrogallol-based compounds are more potent than others such as catechol or resorcinol, gallic acid, and the hydroxycinnamic acid (ferulic acid) are destructing the bacterial cell wall of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, leading to leakage of cellular contents. These compounds have stronger activity against Gram-positive microorganisms, and some of them showed good synergism with antibiotics, for example, pentagalloylglucopyranose, is shown a synergism with penicillin G against methicillin-resistant S. aureus, another example is the interesting synergism between epicatechin gallate and oxacillin where the minimal inhibitory concentrations of oxacillin reduced around 500 times by the addition of epicatechin gallate to the antibiotic.

Biologically Active Compounds of Plants: Structure-Related Antioxidant, Microbiological and Cytotoxic Activity of Selected Carboxylic Acids

“…Changes in membrane properties. Phenolic acids (especially hydrophobic compounds) affect the properties of cell membranes (charge, permeability) through changes in hydrophobicity, reduction of negative surface charge, and the formation of pores in the membranes and leakage of intracellular components [ 135 , 136 ]. Anti-biofilm formation.…”

Phenolic Compounds Diminish Antibiotic Resistance of Staphylococcus Aureus Clinical Strains

“…Regrettably, their excessive, unreasonable, and inappropriate use has led to the selection and expansion of resistant bacterial strains and dramatically increased treatment failure ratio. Bacteria have developed many different mechanisms of resistance such as: (1) modification of the antibiotic binding site; (2) production of enzymes which can degrade or change the antibiotic structure; (3) mutations in genes encoding transport proteins resulting in cell wall permeability disruptions; (4) active pumping out of the antibiotics molecules [ 1 ]. In the light of the fact that the PDR (pandrug-resistant) bacterial strains resistant to all available antibiotics are being isolated all over the world the notion that the golden age of antibiotics is over and we entered the “post-antibiotic era” is fully justified.…”

Antimicrobial activity of berries extracts of four Ribes species, their phenolic content and anthocyanin composition

“…The extract from the variety 'Corona', which had the highest anthocyanins-tototal phenolics ratio, was effective as an inhibitor of bacterial growth only in higher concentrations and was the least promising as a food preservative. This may be due to the antimicrobial properties of other phenolics such as myricetin, quercetin, tannins, ferulates, and others (Puupponen-Pimia et al, 2001;Daglia, 2012;Aldulaimi, 2017).…”