Bioactive compounds sourced from Terminalia spp. in bacterial malodour prevention: an effective alternative to chemical additives

Abstract

Objective Recently, our group reported that extracts prepared from the Australian native plant Terminalia ferdinandiana Exell. are potent inhibitors of the growth malodorous bacteria with similar efficacy to triclosan and through these results, we highlighted a potential biological alternative to the current chemical additives. Other members of the genus Terminalia are also well documented for their antibacterial potential and tannin contents and thus were investigated as potential deodorant additives. Methods Solvent extractions prepared from of selected Indian, Australian and South African Terminalia spp. were screened by disc diffusion and liquid dilution assays against C. jeikeium, S. epidermidis, P. acnes and B. linens. The antibacterial activity was quantified by liquid dilution MIC assays. The extracts were screened for toxicity using Atremia franciscana nauplii and HDF cell viability bioassays. High‐resolution time‐of‐flight (TOF) LC‐MS and GC‐MS headspace fingerprint analysis was used to detect tannin, flavonoid and terpenoid components in the extracts. Results Bacterial growth inhibition was observed in all Terminalia extracts with the methanolic T. chebula, T. carpenteriae and T. sericea extracts the most promising bacterial growth inhibitors, yielding MIC values as low as 200 µg mL−1. Toxicity analyses of the extracts were favourable, and we determined that the methanolic T. chebula, T. carpenteriae and T. sericea extracts were all non‐toxic. Using previously detected T. ferdinandiana antimicrobials as benchmarks, LC‐MS and GC‐MS fingerprint analyses revealed similar compounds in the methanolic T. chebula, T. carpenteriae and T. sericea extracts. Conclusion Through these results, we propose that Terminalia spp. extracts may be useful deodorant additives to inhibit the growth of axillary and plantar malodorous bacteria, offering a biological alternative to their chemically synthesized counterparts.

Kunzea ambigua (Sm.) Druce and Kunzea flavescens C.T. White and W.D. Francis Essential Oils Inhibit the Growth of Some Bacterial Triggers of Inflammatory Diseases

“…essential oils and hydrosol was determined using a modified disc diffusion assay. 22,38 Briefly, 100µL of the each bacterial suspension in log phase was spread onto individual nutrient agar plates and the extracts were tested for antibacterial activity using 5mm sterilised filter paper discs. The discs were each infused with 10µL of the individual plant extract, allowed to dry and placed onto the inoculated plates.…”

“…The minimum inhibitory concentration (MIC) of each extract was also quantified by disc diffusion assay. 40,41 Graphs of the zone of inhibition (ZOI) versus ln concentration were plotted and MIC values were calculated by linear regression.…”

An Examination of the Antioxidant Capacity, Antibacterial Activity and Toxicity of Commercial Kale and Spirulina Powders

“…Antimicrobial activity of the kale and spirulina extracts was determined using a modified disc diffusion assay. [43][44][45][46] Briefly, 100µL of the each bacterial suspension in log phase was spread onto individual nutrient agar plates and the extracts were tested for antibacterial activity using 6mm sterilised filter paper discs. The discs were each infused with 10µL of the individual plant extract, allowed to dry and placed onto the inoculated plates.…”

“…The minimum inhibitory concentration (MIC) of each extract was also quantified by disc diffusion assay. [43][44][45][46] Graphs of the zone of inhibition (ZOI) versus ln concentration were plotted and MIC values were calculated by linear regression.…”

The Janus Corner

“…The genus Terminalia comprise over 250 species and are well-documented for their use in traditional (Ayurveda) medicines. 1 Investigations into the medicinal potential of these plants has revealed that they not only contain numerous anti-inflammatory and antibacterial compounds [2][3][4][5][6][7] but can prevent the development of cancers, as well as the induction of apoptosis of cancerous cells. 8 Recently, an article that was written by Cock and Cheesman 8 that summarises the available research on Terminalia spp.…”