Determination of the antimicrobial activity of purified melanin from the ink of Octopus mimus Gould, 1852 (Cephalopoda: Octopodidae)

Abstract

Cephalopods are important biomedical models oriented to vertebrates, with pharmacological potential. These animals possess a gland of ink, which produces a black or brown liquid (ink), with high concentration of melanin, which have been ascribed antibacterial properties. Based on this information, we sought to determinate the protective effect of Octopus mimus melanin through the extraction and purification of the ink, and further evaluation of its antimicrobial activity against Staphylococcus aureus and Escherichia coli. Our results indicate a moderate antimicrobial activity, compared with commercial antibiotic (ampicillin 0.05 mg mL-1), and a minimum inhibitory concentration differential between the two bacterial strains.