Antibacterial Activity of Pharmaceutical-Grade Rose Bengal: An Application of a Synthetic Dye in Antibacterial Therapies

Rose bengal has been used in the diagnosis of ophthalmic disorders and liver function, and has been studied for the treatment of solid tumor cancers. To date, the antibacterial activity of rose bengal has been sporadically reported; however, these data have been generated with a commercial grade of rose bengal, which contains major uncontrolled impurities generated by the manufacturing process (80–95% dye content). A high-purity form of rose bengal formulation (HP-RBf, >99.5% dye content) kills a battery of Gram-positive bacteria, including drug-resistant strains at low concentrations (0.01–3.13 μg/mL) under fluorescent, LED, and natural light in a few minutes. Significantly, HP-RBf effectively eradicates Gram-positive bacterial biofilms. The frequency that Gram-positive bacteria spontaneously developed resistance to HP-RB is extremely low (less than 1 × 10−13). Toxicity data obtained through our research programs indicate that HP-RB is feasible as an anti-infective drug for the treatment of skin and soft tissue infections (SSTIs) involving multidrug-resistant (MDR) microbial invasion of the skin, and for eradicating biofilms. This article summarizes the antibacterial activity of pharmaceutical-grade rose bengal, HP-RB, against Gram-positive bacteria, its cytotoxicity against skin cells under illumination conditions, and mechanistic insights into rose bengal’s bactericidal activity under dark conditions.

Excess Iodine Exposure Acutely Increases Salivary Iodide And Antimicrobial Hypoiodous Acid Concentrations In Humans

The lactoperoxidase (LPO)-hydrogen peroxide-halides reaction (LPO system) converts iodide and thiocyanate (SCN-) into hypoiodous acid (HOI) and hypothiocyanite (OSCN-), respectively. Since this system has been implicated in defense of the airways and oropharynx from microbial invasion, we measured the concentrations of these analytes in human saliva before and after iodine administration to test the hypothesis that an iodide load increases salivary iodide and HOI concentrations. Salivary iodide, SCN-, HOI and OSCN- were measured using standard methodology. Salivary iodide and HOI levels significantly increased after iodinated contrast injection compared with baseline levels, whereas there was no significant change in salivary SCN- and OSCN- levels. The contrast dye iodine load and changes of salivary iodide and HOI levels were positively correlated, suggesting that higher iodide in the circulation increases iodide output and salivary HOI production. Excess iodine exposure in humans increases the salivary output of iodide, increasing salivary HOI concentrations with no effect on SCN-/OSCN- levels. This first of its kind study suggests that a sufficient but safe iodide supplementation may augment the generation of antimicrobial HOI by the salivary LPO system against airborne viral pathogens, including coronaviruses and influenza viruses, a possible inexpensive means of effectively curbing viral pandemics.

Development of a mouse model of ascending infection and preterm birth

Background Microbial invasion of the intraamniotic cavity and intraamniotic inflammation are factors associated with spontaneous preterm birth. Understanding the route and kinetics of infection, sites of colonization, and mechanisms of host inflammatory response is critical to reducing preterm birth risk. Objectives This study developed an animal model of ascending infection and preterm birth with live bacteria (E. coli) in pregnant CD-1 mice with the goal of better understanding the process of microbial invasion of the intraamniotic cavity and intraamniotic inflammation. Study design Multiple experiments were conducted in this study. To determine the dose of E. coli required to induce preterm birth, CD-1 mice were injected vaginally with four different doses of E. coli (103, 106, 1010, or 1011 colony forming units [CFU]) in 40 μL of nutrient broth or broth alone (control) on an embryonic day (E)15. Preterm birth (defined as delivery before E18.5) was monitored using live video. E. coli ascent kinetics were measured by staining the E. coli with lipophilic tracer DiD for visualization through intact tissue with an in vivo imaging system (IVIS) after inoculation. The E. coli were also directly visualized in reproductive tissues by staining the bacteria with carboxyfluorescein succinimidyl ester (CFSE) prior to administration and via immunohistochemistry (IHC) by staining tissues with anti-E. coli antibody. Each pup’s amniotic fluid was cultured separately to determine the extent of microbial invasion of the intraamniotic cavity at different time points. Intraamniotic inflammation resulting from E. coli invasion was assessed with IHC for inflammatory markers (TLR-4, P-NF-κB) and neutrophil marker (Ly-6G) for chorioamnionitis at 6- and 24-h post-inoculation. Results Vaginally administered E. coli resulted in preterm birth in a dose-dependent manner with higher doses causing earlier births. In ex vivo imaging and IHC detected uterine horns proximal to the cervix had increased E. coli compared to the distal uterine horns. E. coli were detected in the uterus, fetal membranes (FM), and placenta in a time-dependent manner with 6 hr having increased intensity of E. coli positive signals in pups near the cervix and in all pups at 24 hr. Similarly, E. coli grew from the cultures of amniotic fluid collected nearest to the cervix, but not from the more distal samples at 6 hr post-inoculation. At 24 hr, all amniotic fluid cultures regardless of distance from the cervix, were positive for E. coli. TLR-4 and P-NF-κB signals were more intense in the tissues where E. coli was present (placenta, FM and uterus), displaying a similar trend toward increased signal in proximal gestational sacs compared to distal at 6 hr. Ly-6G+ cells, used to confirm chorioamnionitis, were increased at 24 hr compared to 6 hr post-inoculation and control. Conclusion We report the development of mouse model of ascending infection and the associated inflammation of preterm birth. Clinically, these models can help to understand mechanisms of infection associated preterm birth, determine targets for intervention, or identify potential biomarkers that can predict a high-risk pregnancy status early in pregnancy.

Gut transcriptome reveals differential gene expression and enriched pathways linked to immune activation in response to weaning in pigs.

Weaning represents one of the most critical periods in pig production associated with increase in disease risk, reduction in performance and economic loss. Physiological changes faced by piglets during the weaning period have been well characterised, however little is currently known about the underlying molecular pathways involved in these processes. As pig meat remains one of the most consumed sources of protein worldwide, understanding how these changes are mediated is critical to improve pig production and consequently sustainable food production globally. In this study, we evaluated the effect of weaning on transcriptomic changes in the colon of healthy piglets over time using an RNA-sequencing approach. The findings revealed a complex and coordinated response to weaning with the majority of genes found to be rapidly differentially expressed within one day post weaning. Multiple genes and pathways affected by weaning in the colon were associated with immune regulation, cell signalling and bacterial defence. NOD-like receptors, Toll-like receptor and JAK-STAT signalling pathways were amongst the pathways significantly enriched. Immune activation was evidenced by the enrichment of pathways involved in interferon response, cytokines interactions, oxidoreductase activities and response to microbial invasion. Biosynthesis of amino acids, in particular arginine, was also amongst the most enriched KEGG pathways in weaned pigs, reinforcing the critical role of arginine in gut homeostasis under stress conditions. Overall, transcriptomic and physiological results suggest that pigs going through the weaning transition undergo a transient period of inflammatory state with a temporary breakdown of barrier functions in the gut. These findings could provide valuable tools to monitor host response post weaning, and may be of particular relevance for the investigation and development of intervention strategies aimed to reduce antibiotic use and improve pig health and performance. Keywords: Pig, Weaning, RNA-sequencing, Transcriptomic, Gut, Immune response.

Evaluation of The Antioxidant, Antimicrobial, and Anticancer Activities of Dicliptera bupleuroides Isolated Compounds Using In Vitro and In Silico Studies

Phytochemical investigation of chloroform fraction (DBC) and ethyl acetate fraction (DBE) of D. bupleuroides (Acanthaceae) resulted in the isolation of β-sitosterol (1) from DBC and vanillic acid (2) from DBE, which were first to be isolated from D. bupleuroides. β-Sitosterol (1) exhibited substantial antioxidant activity (IC50 = 198.87 µg/mL), whereas vanillic acid (2) showed significant antioxidant power (IC50 = 92.68 µg/mL) employing 1,1-diphenyl-2-picrylhydrazyl (DPPH*) radical scavenging capacity assay. Both compounds showed pronounced antimicrobial activity using the agar disc diffusion method, particularly against fungi showing MIC values of 0.182 and 0.02 concerning Candida albicans, respectively, and 0.001 mg/mL regarding Penicillium notatum. They revealed considerable antibacterial activity with MIC values ranging between 0.467 and 0.809 mg/mL. Vanillic acid (2) exhibited substantial anticancer potential displaying 48.67% cell viability at a concentration of 100 μg/mL using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-Diphenyl-2H-Tetrazolium Bromide) assay concerning HepG2 cell lines. These results were further consolidated by in silico studies on different enzymes, where vanillic acid displayed a high fitting score in the active pockets of DNA-gyrase, dihydrofolate reductase, aminoglycoside nucleotidyltransferase, and β-lactamase. It also inhibited human cyclin-dependent kinase 2 (CDK-2) and DNA topoisomerase II, as revealed by the in silico studies. ADME/TOPKAT (absorption, distribution, metabolism, excretion, and toxicity) prediction showed that vanillic acid exhibited reasonable pharmacodynamic, pharmacokinetic, and toxicity properties and, thus, could perfectly together with D. bupleuroides crude extract be incorporated in pharmaceutical preparations to counteract cancer and microbial invasion, as well as oxidative stress. Thus, it is concluded that D. bupleroides could be a potential source of therapeutically active compounds, which would be helpful for the discovery of clinically effective and safe drugs.

The Roles of Gasdermin D in Coronavirus Infection and Evasion

Pyroptosis is lytic, programmed cell death and plays a critical role against microbial invasion, functioning as an innate immune effector mechanism. The pore-forming protein gasdermin D (GSDMD), a member of gasdermin family proteins, is a primary effector of pyroptosis. The cleavage of inflammasome-associated inflammatory caspases activates GSDMD to liberate the N-terminal effector domain from the C-terminal inhibitory domain and form pores in the cellular plasma membrane. Emerging evidence shows that the pore-forming activity of GSDMD beyond pyroptosis and modifies non-lytic cytosolic protein secretion in living cells and innate immunity. While the essential roles of GSDMD in bacterial infection and cancer have been widely investigated, the importance of GSDMD in virus infection, including coronaviruses, remains elusive. Here, we review the current literature regarding the activation and functions of GSDMD during virus infections. Last, we further discuss the roles of GSDMD and the therapeutic potential of targeting this GSDMD pore-forming activity in coronavirus diseases.

Effect of cell phone use on salivary components; a review of literature

Mobile phones have been increasingly used in the past decade and have become a cultural instrument. There is a great concern over the harmful effects of electromagnetic and radiofrequency waves as well as microwaves generated by mobile phones and their telecommunication stations on health. The saliva plays an important role in preserving oral homeostasis as the first defensive line against the microbial invasion which protects oral mucosa mechanically and immunologically. A search was run in Pub med, Goggle Scholar, Medline, and Web of Science databases using the following keywords: cell phone, mobile phone, antioxidant profile, saliva, oxidative stress, interleukin, and inflammation. Sixty-five published articles were identified. Studies on the use of cell phones as educational aids, the use of immune histochemistry on salivary glands, or the evaluation of saliva in individuals with specific conditions, such as the use of orthodontic brackets, were excluded. In addition, duplicate articles are eliminated, and finally, 14 articles were included in the present study. Nowadays mobile phone is very popular, causing concern about the effect it has on people’s health. Parotid salivary glands are in close contact with a cell phone while talking with the phone and the possibility of being affected by them; so this study was designed to investigate the effect of cell phone use on salivary components.

INVESTIGATION OF SPECIES COMPOSITION OF MICROFLORA IN PERIODONTAL POCKETS IN PATIENTS WITH GENERALIZED PERIODONTITIS AND METABOLIC SYNDROME

Among dental diseases, periodontal diseases rank one of the leading places and are considered as the most pressing issues of modern dentistry. The presence of concomitant somatic pathology, in particular, cardiovascular, endocrinological, autoimmune diseases is an important factor that considerably determines the course and prognosis of periodontal disease. Metabolic syndrome is regarded as an urgent social and medical issue due to its high prevalence among the general population and its contribution to the development and progression of cardiovascular disease. The number of reports and scientific interest in the metabolic syndrome has grown up significantly in recent years, but despite the significant number of studies, the oral microbiome in patients with periodontal disease and underlying metabolic syndrome is still remaining insufficiently studied. The aim of this work was to investigate the species composition of the microflora in periodontal pockets and the frequency of excretion of certain types of microorganisms in the acute generalized periodontitis in patients with metabolic syndrome. A microbiological study was performed in 30 people with metabolic syndrome and generalized periodontitis, who formed the main group, and in 30 people with generalized periodontitis without endocrinological pathology, who formed a comparison group. The results of microbiological examination indicate pathological changes in the oral microbiome in the patients with metabolic syndrome demonstrating a predominance of periodontal pathogens. It can be assumed that the components of the metabolic syndrome can initiate and support microbial invasion thus resulting in the inflammatory reaction of periodontal tissues. There is a similarity between pathogenetic mechanisms of metabolic syndrome and periodontal disease that lead to the impairment of all types of metabolism: protein, lipid, mineral, carbohydrate. As a consequence, this contributes to the progressive destruction of oral tissues. The obtained data enable to suggest the dependence between the presence of the patient's metabolic syndrome and the development of intensive damage to periodontal tissues.

Dichotomous roles of neutrophils in modulating pathogenic and repair processes of inflammatory bowel diseases

Neutrophils are considered as complex innate immune cells and play a critical role in maintaining intestinal mucosal homeostasis. They exert robust pro-inflammatory effects and recruit other immune cells in the acute phase of pathogen infection and intestinal inflammation, but paradoxically, they also limit exogenous microbial invasion and facilitate mucosal restoration. Hyperactivation or dysfunction of neutrophils results in abnormal immune responses, leading to multiple autoimmune and inflammatory diseases including systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel diseases (IBD). As a refractory intestinal inflammatory disease, the pathogenesis and progression of IBD are associated with complicated immune response processes in which neutrophils are profoundly involved. However, the consensus on potential roles of neutrophils in modulating pathogenic and repair processes of IBD remains not fully understood. Accumulated infiltrating neutrophils cross the epithelial barrier and contribute to microbial dysbiosis, aggravated intestinal architectural damage, compromised resolution of intestinal inflammation and increased risk of thrombosis during IBD. Paradoxically, activated neutrophils are also associated with effective elimination of invaded microbiota, promoted angiogenesis and tissue restoration of gut mucosa in IBD. Here, we discuss the beneficial and detrimental roles of neutrophils in the onset and resolution of intestinal mucosal inflammation and provide a precise overview of neutrophil functions in the pathogenesis of IBD.