Assessment of therapeutic efficacy of medicinal plants used against Ciguatera Fish Poisoning through inhibition of nitric oxide

Titre: 
Assessment of therapeutic efficacy of medicinal plants used against Ciguatera Fish Poisoning through inhibition of nitric oxide production and brevetoxin binding
Auteurs: 
Kumar-Roiné S, Darius HT, Matsui M, Reybier-Vuattoux K, Chinain M, Pauillac S, Laurent D
Type de communication: 
Communication orale
Conférence: 
Congrès Ciguatéra et Biotoxines associées (Nouméa, Nouvelle-Calédonie)
Année: 
10/2008

Ciguatera Fish Poisoning (CFP) is an intertropical ichtyosarcotoxism that manifests in complex assortment of symptoms in humans. Ciguatoxins (CTXs), issued from Gambierdicus spp., are causative agents of this intoxication.
Recently, we have shown that a Pacific CTX, P-CTX-1B modulates the production of nitric oxide (NO) free radical via the activation of inducible nitric oxide synthase (iNOS). Though involved in vital physiological processes, detrimentally large amount of NO resulting from iNOS enzyme up-regulation is implicated in many physiopathological conditions. The implication of iNOS could clarify the inflammatory nature of certain symptoms of CFP. Likewise, ionic disturbances observed in human during CFP result from strong binding of CTXs to voltage-sensitive sodium channel (VSSC). This persistent binding poses a problem to the elimination of the toxins from the body, explaining the chronicity, recurrence and sensitization of the signs.
As opposed to modern therapy, which remains primarily symptomatic and supportive, many traditional remedies used in the Pacific against CFP have been reputed to be effective. Consequently, the two molecular activities, modulation of iNOS/NO and binding to VSSC, have been exploited in the screening of medicinal plants. Some plant extracts demonstrated iNOS/NO inhibitory activity (assessed by quantitative polymerase chain reaction and nitrite assay), while others showed inhibition of tritiated brevetoxin ([H]PbTx-3) binding to VSSC. These plants are promising candidates for further pharmacological evaluation.