Narasin (4-methylsalinomycin) is a carboxylic polyether antibiotic isolated from Streptomyces aureofaciens in 1978. Although Narasin is a derivative of Salinomycin, the metabolites are produced by different species and are not co-metabolites. Narasin is an ionophore with activity against Gram positive bacteria including anaerobes and mycoplasma, and also possesses antiviral and limited antifungal activity. Narasin, a coccidiostat, is used in the animal health industry as a feed additive antibiotic for growth enhancement, and control of Eimeria. Ionophore toxicity has been reported in many mammalian and avian species but sensitivity to toxicity varies between species and ionophores. Narasin also possesses antiprotozoal activity in humans and animals.
Narasin is soluble in ethanol, methanol, DMF or DMSO but practically insoluble in water.
Berg DH and Hamill RL (1978) The isolation and characterization of Narasin, a new polyether antibiotic. J. Antibiot. (Tokyo) 31(1):1-6 PMID 627518
Kadykalo S et al (2018) The value of anticoccidials for sustainable global poultry production. Int. J. Antimicrob. Agents 51(3):304-310
Chen J et al (2020) Narasin inhibits tumor metastatis and growth of ERα-positive breast cancer cells by inactivation of the TGF-B/SMAD3 and IL-6/STAT3 signaling pathways. Molec. Med. Rep. 22(6):5113-5124
|Mechanism of Action||Antiparasitic activity of Narasin is via inteference in the ion transport system leading to cell death. Gram-negative bacteria do not permit hydrophobic ionophore molecules through their cell walls, thus are not susceptible to ionophores.|
|Spectrum||Narasin has activity against Gram-positive bacteria including anaerobes. Antiprotozoal activity.|
The USDA has a method for the major ionophores in tissue samples based on purificaiton of sample extracts by silica gel, alumina, or ion-exchange column chromatophy, determination by TLC, and detection via bioautography. Many alternative methods can be used based on immunoassays, biosensors, and HPLC.
Concerns regarding the development of antimicrobial resistance (AMR) in bacteria explosed to ionophores have been raised, and research is ongoing to review the impact of resistance to ionophores.
|Cancer Research Applications||
Narasin inhibits tumor metastatis and growth of ERα-positive breast cancer cells via inactivation of the TGF-β/SMAD3 and IL-6/STAT3 signaling pathways. In vitro, it inhibited cell proliferation, migration, and invasion in ER+ breast cancer cell lines MCF-7 and T47D. In vivo, it reduced the number of tumor metastasis nodules, tumor volume and weight without apparent toxicity in human MCF-7 nude mouse models, specifically the left ventiricle injection tumor metastasis and xenograrft model. Taken together, research indicates that Narasin may be a suitable candidate for potential therapeutic properties (Chen et al, 2020).