Reversible anti-settlement activity againstAmphibalanus(=Balanus)amphitrite, Bugula neritina, andHydroides elegansby a nontoxic pharmaceutical compound, mizolastine

Abstract

Mizolastine, an antihistamine pharmaceutical, was found to significantly inhibit larval settlement of the barnacle Amphibalanus (=Balanus) amphitrite, the bryozoan Bugula neritina, and the polychaete Hydroides elegans with EC(50) values of 4.2, 11.2, and 4.1 microg ml(-1), respectively. No toxicity against the larvae of these three species was observed at the concentration range tested during incubations with mizolastine. To determine whether the anti-settlement activity of mizolastine is reversible, recovery bioassays using these three species were conducted. More than 70% of the larvae that had been exposed for 4 h to mizolastine at concentrations four-fold greater than their respective EC(50) values completed normal metamorphosis. The results of the recovery bioassay provide evidence that the anti-settlement effect of mizolastine is reversible in addition to being nontoxic. The anti-settlement activities of several intermediates of the synthesis process of mizolastine were also examined. One of the intermediates, 2-chloro-1-(4-fluorobenzyl)-1H-benzo[d]imidazole, inhibited larval settlement and metamorphosis with low toxicity. These results may improve the understanding of the key functional group responsible for the anti-settlement activity of mizolastine.

Larval metamorphosis of the mussel Mytilus galloprovincialis Lamarck, 1819 in response to neurotransmitter blockers and tetraethylammonium

“…Numerous literature have documented different pharmacological compounds that induce or inhibit larval metamorphosis of many marine invertebrates including hydroids, bryozoans, polychaetes, mollusks, barnacles, sea urchins and ascidians. These studies provide valuable information that has application in the fields of biofouling, antifouling and aquaculture (Cooper 1983;Rittschof et al 1992;Martinez et al 1999;Zhao et al 2003;Gapasin and Polohan 2004;García-Lavandeira et al 2005;Yu et al 2007;Zhou et al 2009). In the present investigation, the authors have demonstrated that chemical compounds chlorpromazine, amitriptyline and TEA inhibit larval metamorphosis of the mussel M. galloprovincialis.…”

Histamine is a modulator of metamorphic competence in Strongylocentrotus purpuratus(Echinodermata: Echinoidea)

“…It will be important to analyze the concentration of HA in the seawater around such biofilms as well as in algal turf and crustose coralline algae to test their role in the settlement response of sea urchin larvae. This is particularly relevant as HA signaling may be involved in the settlement processes of barnacles, bryozoans and polychaetes as well [65]. Specifically, experiments have shown that a H1R antagonist, mizolastine, has inhibitory effects on the settlement response of selected species from these groups [65].…”

“…This is particularly relevant as HA signaling may be involved in the settlement processes of barnacles, bryozoans and polychaetes as well [65]. Specifically, experiments have shown that a H1R antagonist, mizolastine, has inhibitory effects on the settlement response of selected species from these groups [65]. Although no further investigations into the signaling mechanisms of HA have been accomplished, these data suggest that HA signaling may be widespread in the marine environment.…”

Designing a Laboratory Bioassay for Evaluating the Efficacy of Antifouling Paints on Amphibalanus amphitrite Using a Flow-Through System

“…The condition of cyprids used in the bioassays for each culture batch was checked by observing mortality and settlement rates. That is, 10 individuals of 3-day-old cyprids were placed in each well of a 12-well polystyrene plate, with each well filled with 4 mL of the filtered seawater, and the number of juveniles that settled and dead cyprids were counted under a dissecting microscope after 48 h [40][41][42].…”