Taurine Haloamines and Biofilm: II. Efficacy of Taurine Bromamine and Chlorhexidine Against Selected Microorganisms of Oral Biofilm

Bromamine T, a stable active bromine compound, prevents the LPS‑induced inflammatory response

Inflammation is the most common cause of most acute and chronic debilitating diseases. Towards unveiling novel therapeutic options for patients with such complications, N‑bromotaurine (TauNHBr) has emerged as a potential anti‑inflammatory agent; however, its therapeutic efficacy is hindered due to its relatively poor stability. To address this challenge, the present study focused on examining the effects of a stable active bromine compound, named bromamine T (BAT). The present study examined the protective properties of BAT against lipopolysaccharide (LPS)‑mediated inflammation in vitro, by using LPS‑stimulated murine J774.A1 macrophages (Mφs), as well as in vivo, by using a murine LPS‑mediated air‑pouch model. Additionally, its efficacy was compared with that of taurine, a known potent anti‑inflammatory molecule. In LPS‑stimulated J774A.1 Mφs, BAT and taurine were very effective in reducing the secretion of pro‑inflammatory mediators. The in vitro experiments indicated that LPS‑mediated inflammation was attenuated due to the protective properties of BAT and of taurine, probably through the inhibition of phosphorylated p65 NF‑κB subunit (Ser 536) nuclear translocation. The in vivo experiments also revealed that BAT and taurine inhibited LPS‑mediated inflammation by reducing total cell/polymorphonuclear cell (PMN) infiltration in the air‑pouch and by decreasing pouch wall thickness. The analysis of exudates obtained from pouches highlighted that the inhibitory effects of BAT and taurine on the secretion of pro‑inflammatory cytokines were similar to those observed in vitro. Notably, the effect of BAT at the highest concentration tested was superior to that of taurine at the highest concentration. Taken together, the findings of the present study indicate that BAT prevents the LPS‑induced inflammatory response both in vitro and in vivo.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review)

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non‑coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N‑Bromotaurine or N‑Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

Alcohol dehydrogenase modulates quorum sensing in biofilm formations of Acinetobacter baumannii

Acinetobacter baumannii (A. baumannii) is a common opportunistic nosocomial pathogen, which is able to produce biofilms on the surface of indwelling medical devices, and consequentially causes severe infections in clinical settings. In order to identify genes that involved in the biofilm formation of A. baumannii, the differential expression of genes between biofilms and planktonic cells was analyzed by RNAseq assay and validated in clinical isolates. The RNAseq data showed that 264 genes were up-regulated, while 240 genes were down-regulated in the biofilms of A. baumannii. Among them, the gene encoding alcohol dehydrogenase (ADH), a known molecule of bacterial quorum sensing (QS) system that plays a key role in biofilm formation bacteria, was one of the most up-regulated gene in both reference strains and clinical isolates. Functional studies using ADH inhibitor disulfiram and activator taurine further demonstrated that the presence of disulfiram significantly inhibit the cell growth, motility and biofilm formation, paralleled by a decreased expression of QS-related genes, including AbaI, A1S_0109, and A1S_0112, in a dose-dependent manner; vice versa, the addition of ADH activator taurine, and QS molecule C12- homoserine lactone synthase (HSL) led a dose-dependent increase of bacterial growth, motility and biofilm production, along with an increased expression of QS-related genes in both reference strains and clinical isolates of A. baumannii. These results suggested that the ADH was a key molecule able to modulate the QS system and promote the biofilm formation, growth and motility in A. baumannii.

Comparative Analysis of Microbicidal and Anti-inflammatory Properties of Novel Taurine Bromamine Derivatives and Bromamine T

Taurine, the most abundant free amino acid in leukocyte cytosol traps hypohalous acids (HOCl and HOBr) to produce N-chlorotaurine (taurine chloramine, NCT and N-bromotaurine (taurine bromamine, Tau-NHBr,) respectively. Both haloamines show anti-inflammatory and antimicrobial properties. However, the therapeutic applicability of Tau-NHBr is limited due to its relatively poor stability. To overcome this disadvantage, we have synthesized the stable N-bromotaurine compounds N-monobromo-2,2-dimethyltaurine (Br-612) and N-dibromo-2,2-dimethyltaurine (Br-422). The aim of this study was to compare anti-inflammatory and microbicidal properties of Br-612 and Br-422 with that of Tau-NHBr and bromamine T (BAT). We have shown that all the tested compounds show similar anti-inflammatory properties. Importantly, the stable N-bromotaurine compounds exerted even stronger microbicidal activity than Tau-NHBr. Finally, for the purpose of topical application of these compounds we have developed a carbomer-based bioadhesive solid dosage form of BAT and Br-612, featuring sustained release of the active substance.