Description
Polymyxin B is a mixture of polymyxin B1, B2, B3 and B1-1 sulfates; polymyxin B is a cationic lipid oligopeptide derived from Bacillus polymyxa that displays antibacterial activity against all gram-negative bacteria except species of Proteus. Polymyxin B kills both proliferative and quiescent cells in vitro. Polymyxin B inhibits cellular respiration by inhibiting type II NADH-quinone oxidoreductase activity. This compound also induces aggregation of lipopolysaccharide (LPS) in bacterial cell membranes, altering membrane potential and causing leakage of cellular components. Polymyxin B has been used to treat septic shock induced by LPS of gram-negative bacteria, preventing LPS-induced caspase activity, Fas expression, Bax/Bcl-2 ratio alteration, and apoptosis.
References
Deris ZZ, Akter J, Sivanesan S, et al. A secondary mode of action of polymyxins against Gram-negative bacteria involves the inhibition of NADH-quinone oxidoreductase activity. J Antibiot (Tokyo). 2013 Oct 30. [Epub ahead of print]. PMID: 24169795.
Zhai B, Lin X. Evaluation of the anticryptococcal activity of the antibiotic polymyxin B in vitro and in vivo. Int J Antimicrob Agents. 2013 Mar;41(3):250-4. PMID: 23313397
Domingues MM, Inácio RG, Raimundo JM, et al. Biophysical characterization of polymyxin B interaction with LPS aggregates and membrane model systems. Biopolymers. 2012;98(4):338-44. PMID: 23193598.
Martin EL, Ranieri VM. Endotoxin removal by polymyxin B immobilized cartridge inactivates circulating proapoptotic factors. Contrib Nephrol. 2010;167:65-76. PMID: 20519900.
