In Vitro Antibacterial Activity of Phx-3 against Helicobacter pylori

Abstract

Phx-3, one of the phenoxazine derivatives, is reported to have inhibitory effect on Mycobacterium species and Chlamydia pneumoniae but not Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes. The bactericidal activities of Phx-3 against Helicobacter pylori strains have not been assessed. Then, we measured minimum inhibitory concentration of Phx-3 for Helicobacter strains and assessed the morphological and biochemical effects of Phx-3 on H. pylori. In present study, it has shown that H. pylori strains including clarithromycin resistant strain and Helicobacter musterae were killed effectively by the treatment with Phx-3. Furthermore, severe morphological changes such as membrane blebbing and formation of hollows in H. pylori were detected. In addition, induction of heat shock protein 60 was observed. Taken together, Phx-3 has antibacterial activity against Helicobacter pylori.

Antibacterial activity of resazurin-based compounds against Neisseria gonorrhoeae in vitro and in vivo

“…The antibacterial activity of this compound is not surprising given its similarity in chemical structure to phenoxazine. Phenoxazine derivatives have been shown to inhibit the growth of a variety of bacterial species, including Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae and Helicobacter pylori [19,20]. To date, resazurin has only been shown to be antimicrobial against F. tularensis and Neisseria spp.…”

Phenoxazine Derivatives Suppress the Infections Caused by Herpes Simplex Virus Type-1 and Herpes Simplex Virus Type-2 Intravaginally Inoculated Into Mice

“…These phenoxazines are anticipated to be clinically useful as benevolent therapeutic drugs against a variety of infectious diseases with few adverse effects, due to their antiviral effects on human cytomegalovirus (11), poliovirus (9), porcine parvovirus (10), and antimicrobial effects against Clamydia pneumoniaee (24), helicobacter pylori (25), and some kinds of non-tuberculosis mycobacteria (13).…”

Prevention of Carcinogenesis and Development of Gastric and Colon Cancers by 2-Aminophenoxazine-3-one (Phx-3): Direct and Indirect Anti-Cancer Activity of Phx-3

“…However, no further characterization of its bioactivity was carried out, possibly due to its weaker (and questionable) antibiotic effects against various microbes except for Mycobacterium tuberculosis , and therefore, it was named questiomycin. Tomoda and colleagues found in 1986 [2] that Phx-3 can be produced during the reaction of human erythrocytes or hemoglobin with o -aminophenol, and later demonstrated that it does exert strong anticancer effects both on various cancer cell lines [3–8] and cancer cell-transplanted mice in vivo [9,10], as well as antimicrobial effects against Helicobacter pylori [11], Chlamydia pneumoniae [12], some mycobacterial species [13], and herpes viruses [14]. Their studies demonstrated that Phx-3 causes apoptotic cell death in the gastric and colon cancer cell line by decreasing intracellular pH, dysregulating the function of mitochondria, and activating the caspase signaling [8,15–17].…”