Antimicrobial activity of Tetrodotoxin extracted from liver, skin and muscles of puffer fish, Lagocephalus sceleratus inhabiting Mediterranean Sea, Egypt

Abstract

Tetrodotoxin (TTX) is a strong marine toxin which is a powerful sodium channel inhibitor. So far, there is no known antidote for TTX to block its toxicity. Therefore, the main aim of this study was to isolate and characterize TTX from the puffer fish, Lagocephalus sceleratus (L. sceleratus) in cold and warm seasons and test its antimicrobial activity. The obtained results showed antibacterial and antifungal activity of the crude extracts of TTX isolated from liver, skin and muscles of L. sceleratus. TTX isolated from of the liver extract showed broad-spectrum antibacterial activity where it showed its maximum activity against Escherichia coli (22.24 mm ± 0.96) as gram negative bacteria and against Bacillus subtilis (17.51 mm ± 0.51) as gram positive bacteria. Its minimum activity, however, was shown against Vibiro cholerae (9.22 mm ± 0.65). The hepatic TTX extract showed its maximum antifungal activity at 19.21mm ± 0.59 against Aspergillus fumigatus where TTX extract from skin showed its minimum activity against Trichophyton rubrum at 5.33 mm ± 0.52. The highest TTX levels in the livers, skins and muscles of female fish were found in winter (30.33, 3.38 and 2.26 µg/g respectively). The TTX level in the muscle of male fish in summer was 0.66µg/g but was otherwise below the toxic limit. The present study indicates to that TTX from L. sceleratus possesses antimicrobial activities, which depends on the season and sex.