Background:

Lasalocid is an ionophore antibiotic.

Lasalocid is produced by Streptomyces lasaliensis and is a mixture of several closely related homologue substances A, B, C, D, E. The sum of the lasalocid homologues B, C, D, E is limited to 10% of the total weight of the active substance, lasalocid.

In vitro: A previous study was conducted to compare effects of the combined use of lasalocid and silybin in chicken hepatoma cells and rat myoblasts cell lines cultures. Results showed that in all performed tests, the lowest lasalocid EC50-values were obtained for chicken hepatocytes. In the rat myoblasts cultures, the lowest lasalocid EC50-values were found. Moreover, a lack of silybin cytotoxic effect was proven for the studied cell lines. An interaction between both substances resulted in a great decrease of lasalocid cytotoxicity. The isobolograms and combination index indicated a significant antagonistic nature of silybin effect in the course of lasalocid cytotoxicity [1].

In vivo: In a animal study, chickens 8 or 9 days old were given a completely purified crystalline amino acid diet. Results showed that the requirement for sulphur-containing amino acids (SAA) was neither increased nor decreased by lasalocid at 125 mg/kg diet. Moreover, lasalocid could cause a significant increase in gain and gain/feed intake when added to diets that were deficient in SAA, but it led to a marked decrease in performance when added to diets adequate in SAA. In addition, at moderate levels of SAA deficiency, lasalocid at 125 mg/kg could neither increase nor decrease the rate and efficiency of weight gain and there was no evidence of the SAA X lasalocid interaction when lasalocid was given in a typical starter diet of maize and soya [2].

Clinical trial: So far, no clinical study has been conducted.

参考文献:
[1] Radko, L. ,Cybulski, W., and Rzeski, W. The protective effect of silybin against lasalocid cytotoxic exposure on chicken and rat cell lines. Biomed.Res.Int. 2013, 1-8 (2013).
[2] Willis GM, Baker DH. Lasalocid-sulfur amino acid interrelationship in the chick. Poult Sci. 1980 Nov;59(11):2538-43.