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Updated: May 25, 2026

A Fish-feeding Laboratory Bioassay to Assess the Antipredatory Activity of Secondary Metabolites from the Tissues of Marine Organisms
Published on: January 11, 2015
First-time report of metalloproteinases in fish bile and their potential as bioindicators regarding environmental
R A Hauser-Davis1, A A Lima, R L Ziolli
1Pontifícia Universidade Católica - Rio de Janeiro (PUC-Rio), Chemistry Department, Bioanalytics Laboratory, Rua Marquês de São Vicente, 225, Gávea, CEP: 22453-900, Rio de Janeiro, RJ, Brazil. rachel.hauser.davis@gmail.com
Abstract:
Gallbladder bile from 2 fish species, mullet (Mugil liza) and tilapias (Tilapia rendalli), contain substantial matrix metalloproteinases (MMPs). Extensive purification studies were conducted in order to obtain workable samples for SDS-PAGE and zymography analysis. Proteinase activities were assayed by gelatin substrate zymography. Several protein bands were observed, corresponding to molecular weights of 200, 136, 43, 36, 34, 29, 23 and 14 kDa in mullet bile and 179, 97, 79, 61, 54, 45, 36, 33 and 21 kDa in tilapia bile. Specific inhibitor studies were conducted, in which MMPS were inhibited by EDTA and 1,10 phenanthroline, but not by serine and cysteine protease inhibitors, such as phenylmethylsulfonyl fluoride (PMSF) and transepoxysuccinyl-l-leucylamido-l-guanidino butane (E-64), confirming the proteinase identities as MMPs. Differences in proteinase expression were observed in fish from a contaminated and reference site. Some studies regarding MMPs in different fish tissues exist, however this is the first study conducted in fish bile, and their involvement in detoxification processes and organism protection against the effects of aquatic contaminants may be a possibility.

