Oxytetracycline hydrochloride is an antibiotic belonging to the tetracycline class. Oxytetracycline hydrochloride potent inhibits Gram-negative and Gram-positive bacteria. Oxytetracycline hydrochloride is a protein synthesis inhibitor and prevents the binding from aminoacil-tRNA to the complex m-ribosomal RNA. Oxytetracycline hydrochloride also possesses anti-HSV-1 activity[1][2][3].

Oxytetracycline is an important member of the bacterial aromatic polyketide family, which is a structurally diverse class of natural products. Oxytetracycline is synthesized by a type II polyketide synthase that generates the poly-beta-ketone backbone through successive decarboxylative condensation of malonyl-CoA extender units, followed by modifications by cyclases, oxygenases, transferases, and additional tailoring enzymes[2].

The effects of administration a therapeutic dose of Oxytetracycline (82.8 mg/kg of bw to 1 % bw/day) for 10 days are species specific. Oxytetracycline increases the relative liver weight in Morone chrysops x M. saxatilis, the enzymatic activity of CYP3A4 in Ictalurus punctatus, protein expression of CYP3A4 in Oreochromis niloticus and depleted the hepatic CYP3A4 in the latter[1].For Oxytetracycline, the limits are 100 μg/kg in muscle and milk, 200 μg/kg in egg, 300 μg/kg in liver and 600 μg/kg in kidney. Oxytetracycline (OTC) is administered to fish as medicated feed at concentrations ranging from 35 to 75 mg a.i kg-1 biomass day-1 for 7-14 days[1].

[1]. Elia AC, et al. Transferability of oxytetracycline (OTC) from feed to carp muscle and evaluation of the antibiotic effects on antioxidant systems in liver and kidney. Fish Physiol Biochem. 2014 Aug;40(4):1055-68. [2]. Pickens LB, et al. Oxytetracycline biosynthesis. J Biol Chem. 2010 Sep 3;285(36):27509-15. [3]. Oguz Guvenmez, et al. A New Treatment Method for Herpes Simplex Virus Type 1-related Skin Lesions. Scientific & Academic. 2019; 8(1): 6-8.