Comparison of Single and Combined Use of Catechin, Protocatechuic, and Vanillic Acids as Antioxidant and Antibacterial Agents against Uropathogenic Escherichia Coli at Planktonic and Biofilm Levels

Abstract

The objective of this study was to evaluate the effect of combining catechin, protocatechuic, and vanillic acids against planktonic growing, adhesion, and biofilm eradication of uropathogenic Escherichia coli (UPEC), as well as antioxidant agents. The minimum inhibitory concentrations (MIC) of protocatechuic, vanillic acids and catechin against the growth of planktonic bacteria were 12.98, 11.80, and 13.78 mM, respectively. Mixing 1.62 mM protocatechuic acid + 0.74 mM vanillic acid + 0.05 mM catechin resulted in a synergistic effect acting as an MIC. Similarly, the minimum concentrations of phenolic compounds to prevent UPEC adhesion and biofilm formation (MBIC) were 11.03 and 7.13 mM of protocatechuic and vanillic acids, respectively, whereas no MBIC of catechin was found. However, combinations of 1.62 mM protocatechuic acid + 0.74 mM vanillic acid + 0.05 mM catechin showed a synergistic effect acting as MBIC. On the other hand, the minimum concentrations to eradicate biofilms (MBEC) were 25.95 and 23.78 mM, respectively. The combination of 3.20 mM protocatechuic acid, 2.97 mM vanillic acid, and 1.72 mM catechin eradicated pre-formed biofilms. The antioxidant capacity of the combination of phenolics was higher than the expected theoretical values, indicating synergism by the DPPH•, ABTS, and FRAP assays. Effective concentrations of catechin, protocatechuic, and vanillic acids were reduced from 8 to 1378 times when combined. In contrast, the antibiotic nitrofurantoin was not effective in eradicating biofilms from silicone surfaces. In conclusion, the mixture of phenolic compounds was more effective in preventing cell adhesion and eradicating pre-formed biofilms of uropathogenic E. coli than single compounds and nitrofurantoin, and showed antioxidant synergy.

Impact of Paraburkholderia phytofirmans PsJN on Grapevine Phenolic Metabolism

“…The less content of glycosylated forms could be due to the secretion of aglycon forms as plant defense mechanisms against microorganisms. Indeed, the aglycon form of these compounds was previously described for their efficient antimicrobial activity against Gram-negative and -positive bacteria [59], as well as for their action against biofilm [60]. Moreover, hydroxybenzoic acids may be involved in signaling, particularly in the induction of defense and stress responses [9].…”

Influence of Pinus brutia bark extract containing phenolic compounds on some commensal and pathogenic bacteria from the intestinal microflora

“…P-hydroxy benzoic acid, gallic acid, ferulic acid, caffeic acid, quercetin, catechin, epicatechin, and apigenin presented in the extract were reported to show antibacterial activity against to F. nucleatum (ATCC 10953) at a dose range of 62.5-2500 µg/ mL (29). Polyphenolic compounds exert antibacterial activity via increasing the permeability of bacterial membranes and decreasing cell surface charges, causing rupture or forming pores, with consequent leakage of intracellular components (30). Catechin also could chelate metals essentials as enzymatic cofactors involved in bacterial growth (31).…”

Effect of Xueniao Capsule on Escherichia coli-Induced Acute Pyelonephritis Rats by 1H NMR-Based Metabolomic Approach

“…It was reported that Coicis Semen, containing a large amount of fatty oils, can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections [19]. Protocatechuic acid and catechin were effective in preventing cell adhesion and eradicating preformed biofilms of uropathogenic E. coli [20]. Engeletin could suppress the expression of TNF- α , IL-1 β , and IL-6 and inhibited NF- κ B signaling pathway activation [21], indicating that it exerted anti-inflammatory properties against LPS-stimulated inflammation.…”