Loss of toxicity by Pseudanabaena galeata in culture

Angelica Nunes Garcia,Célia Leite Sant'Anna,Fernando Pipole,Luciana Retz De Carvalho,Fabiana Elias,Luciana Castro Da Cunha,Silvana Lima Górniak

doi:10.1590/2236-8906-53/2016

Angelica Nunes Garcia, Célia Leite Sant'Anna + Show 5 more

Open Access

https://doi.org/10.1590/2236-8906-53/2016

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Abstract

ABSTRACT Pseudanabaena galeata, a well-known toxin-producer, is commonly found in water supplies. In order to assess potential risks associated with oral exposure to this cyanobacterium, mouse toxicological studies were carried out with the monoespecific strain P. galeata CCIBt 3082, which has been kept in culture since 1996. In our studies, the acute oral lethal dose has been estimated to be 5,000 mg kg-1 bw and, in the oral sub-chronic assays, the animals showed a decrease in weight and presented microscopic intestinal lesions, results that did not correspond to statements by other authors. In their studies, oral administration of the extract, whose acute lethal dose has been established to be 1,000 mg kg-1 bw, led to severe intoxication and promoted hepatic and renal lesions. Toxicity loss of this strain may be the result of reductive evolution that can occur in organisms that remain in static environments for long periods.

Highlights

A first study by our research group, reported that the administration of a single 1.000 mg kg-1 body weight oral dose of P. galeata extract caused mice death over a period of 12 days; no changes were seen following intraperitoneal administration (Cunha et al 2010). These results are different from those described by Teneva et al (2009), which were assigned to microcystins, anatoxin-a and saxitoxin contained in P. galeata extract administered intraperitoneally (i.p.) (Cunha et al 2010, Pipole et al 2010)
The organism - Pseudanabaena galeata Collection of the SP Institute of Botany (CCIBt) 3082 strain was collected from IAG Lake, at the Parque Estadual das Fontes do Ipiranga (PEFI), in São Paulo, on 11 November 1996
Acute median lethal dose determination (DL50), oral administration - Acute median lethal dose determined according to the OECD - 425 protocol was 5,000 mg kg-1 bw of lyophilized 0.1 M acetic acid P.galeata extract

Summary

Introduction

A first study by our research group, reported that the administration of a single 1.000 mg kg-1 body weight (bw) oral dose of P. galeata extract caused mice death over a period of 12 days; no changes were seen following intraperitoneal administration (Cunha et al 2010). These results are different from those described by Teneva et al (2009), which were assigned to microcystins, anatoxin-a and saxitoxin contained in P. galeata extract administered intraperitoneally (i.p.) (Cunha et al 2010, Pipole et al 2010).

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