Modified Green Tea Polyphenols, EGCG-S and LTP, Inhibit Endospore in Three <i>Bacillus</i> spp.

Abstract

Endospores have the ability to withstand extreme temperature, desiccation, ultraviolet radiation and chemicals which make them a threat to the food and healthcare industry. Green tea polyphenols (GTP), contain anti-microbial and anti-spore properties but not stable. In this study, two modified lipophilic green tea polyphenols, epigallocatechin-3-gallate-sterate (EGCG-S) and crude lipophilic green tea polyphenols (LTP), were used to compare their anti-spore effect with EGCG and crude GTP. Purified endospores from Bacillus cereus (B. cereus), B. megaterium and B. subtilis were treated with 1% or 5% of four tea polyphenols. Log reduction showed colony forming units (CFU) reduced significantly in all treated samples, ranging from 1.27 to 4.31 with no survivals (CFU = 0) in four samples (P < 0.05). Average percentage of inhibition for these polyphenols treatment ranged from 91.68% to 100%. The EGCG-S and LTP have equal or better anti-spore activities compared with EGCG and GTP.EGCG-S and LTP were further used to carry out time course study on B. cereus.The results indicated that 15 min of treatment of 1% and 5% LTP and EGCG-S are able to inhibit 98.7% to 100% of germination. Transmission and scanning electron microscopy studies showed that EGCG-S caused surface disruption and damaged spores structural integrity. EGCG-S and LTP are stable anti-spore agents may aid in preventing food and beverage spoilage caused by sporeforming bacteria as well as preventing contamination in the medical industry.

Inhibition of Biofilm Formation by the Synergistic Action of EGCG-S and Antibiotics

“…Thus, in this study, we have used a patented (US8076484B2) esterified derivative of EGCG, EGCG-Stearate (EGCG-S) which improves the bioavailability significantly [74,75]. Previously, we reported that EGCG-S can be used as an anti-spore agent, as it inhibits germination of spores produced by Bacillus species [30]. In 2018, our study highlighted the anti-cariogenic property of EGCG-S as it was able to inhibit the growth and biofilm formation of S. mutans, an etiological agent of dental caries [31].…”

“…EGCG-S has been successfully shown to inhibit spores produced by Bacillus spp. and the growth of Streptococcus mutans (S. mutans) [30,31]. Additionally, EGCG-S was shown to improve the efficacy of antibiotics against various bacteria, thereby making it a potential synergistic anti-bacterial agent [32].…”

Epigallocatechin Gallate-Stearate Enhances the Efficacy of Antibiotics

“…EGCG-S is a more stable derivative that can inhibit the production of bacteria secondary metabolites and thus induces endogenous oxidative stress and decreases biofilm formation [26]. Previous report also suggested that EGCG-S could damage the integrity of endospore coat [11]. The mechanisms of EGCG and EGCG-S may work synergistically with antibiotics to increase the susceptibility of antibiotic on antibiotic resistant bacteria.…”

“…Under normal conditions, EGCG is a water-soluble polyphenol oxidized and metabolized rapidly, which leads to the loss of potent antimicrobial abilities quickly [10]. To overcome the stability issue, the modified lipophilic polyphenols could be an effective agent as green tea polyphenols (GTPs) [11]. EGCG-stearate (EGCG-S), lipid soluble tea polyphenols (LTPs) that were prepared chemically and enzymatically, can significantly improve the bioavailability of GTPs [12] [13].…”

Eco-Friendly Synthesis of Lipophilic EGCG Derivatives and Antitumor and Antioxidant Evaluation

“…EGCG can be modified structurally to improve its lipophilicity, expand its application in lipophilic media, and enhance its cellular absorption in vivo. The fully acetylated derivative (EGCG-P) may act as a pro-drug, leading to higher bioavailability than EGCG itself [10]. Moreover, EGCG peracetated and EGCG fatty acid monoester derivatives may improve the anticancer and neuroprotective activity in an alkyl chain length-dependent manner [11].…”