Antipathogenic Potential of a Polyherbal Wound-Care Formulation (Herboheal) against Certain Wound-Infective Gram-Negative Bacteria

Abstract

This study investigated antipathogenic efficacy of a polyherbal wound-healing formulation Herboheal against three multidrug-resistant strains of gram-negative bacterial pathogens associated with wound infections. Herboheal was evaluated for its quorum-modulatory potential against three different human-pathogenic bacteria, first in vitro through the broth dilution assay and then in vivo in the model host Caenorhabditis elegans. Herboheal at ≥0.1% v/v was able to inhibit (19–55%) in vitro production of quorum sensing-regulated pigments in all these bacteria and seemed to interfere with bacterial quorum sensing by acting as a signal-response inhibitor. This formulation could compromise haemolytic activity of all three bacteria by ∼18–69% and induced their catalase activity by ∼8–21%. Herboheal inhibited P. aeruginosa biofilm formation up to 40%, reduced surface hydrophobicity of P. aeruginosa cells by ∼9%, and also made them (25%) more susceptible to lysis by human serum. Antibiotic susceptibility of all three bacteria was modulated owing to pretreatment with Herboheal. Exposure of these test pathogens to Herboheal (≥0.025% v/v) effectively reduced their virulence towards the nematode Caenorhabditis elegans. Repeated subculturing of P. aeruginosa on the Herboheal-supplemented growth medium did not induce resistance to Herboheal in this mischievous pathogen, and this polyherbal extract was also found to exert a post-extract effect on P. aeruginosa, wherein virulence of the Herboheal-unexposed daughter cultures, of the Herboheal-exposed parent culture, was also found to be attenuated. Overall, this study indicates Herboheal formulation to be an effective antipathogenic preparation and validates its indicated traditional therapeutic use as a wound-care formulation.

Anti-pathogenic potential of a classical ayurvedic Triphala formulation

“…These results indicate that it may be difficult for the pathogenic bacteria to develop complete resistance against polyherbal formulations like Triphala , but not impossible. Though our previous results on other polyherbal formulations ( Joshi et al , 2019 ; Patel et al ., 2019a ) and multicomponent crude plant extracts ( Joshi, 2019 ) have indicated that the probability of pathogens developing resistance against multi-component anti-virulence preparations is low, such a probability can certainly not be ruled out ( Kalia et al ., 2014 ; Singh, 2014 )…”

“…After confirming the anti-infective activity of TF, we investigated (as described in Patel et al ., 2019a ) whether this formulation exerts any post-extract effect (PEE - https://doi.org/10.32388/359873 ) on the test pathogens i.e. whether the virulence-attenuating effect suffered by the parent bacterial culture is retained even in their daughter population never receiving any direct exposure to TF.…”

“…Pseudomonas aeruginosa was available in our institutional culture collection. All the three gram-negative bacteria used in this study were multidrug resistant, and their antibiogram has previously been reported by us ( Joshi et al ., 2019 ; Patel et al ., 2019a ). Additionally, C. violaceum and S. marcescens strains mentioned here have been reported by us as beta-lactamase producers ( Sarvaiya & Kothari, 2017 ).…”

Sonic stimulation at certain frequencies can confer limited protection on nematode host infected with Serratia marcescens

“…Of the pathogenic strains mentioned above, all the gram-negative bacteria were multi-drug resistant, and the C. violaceum and S. marcescens strains used were beta-lactamase producers. Their antibiogram, along with culture conditions and growth media has previously been reported by us [Patel et al, 2019a]. Bird voices recorded at Dang Forest, Ahwa, Gujarat were obtained from Dr. Arun Dholakia, (Zoology Department, PTS Science College, Surat), and their frequency analysis was executed by performing a temporal frequency analysis (TFFT) using NCH WavePad v 7.13.…”

Anti-infective potential of castor oil and ricinoleic acid against selected human-pathogenic bacteria

“…In vitro assays to study interaction of these two items with test bacteria with respect to bacterial growth, quorum-regulated pigment production, biofilm formation, and few other clinically relevant traits were also performed.CO and RA were procured from CDH and Sigma-Aldrich respectively. Methodology of the in vitro and in vivo assays was adopted from our previous publications (Joshi et al, 2019;Patel et al, 2019), which also contains details of the organisms used.Results explaining effect of CO and RA are presented through Figures 1-15, which indicate CO and RA both to be capable of attenuating virulence of pathogenic bacteria. Latter exerted activity at concentrations much lesser than that of CO.…”