Hepatosplenomegaly caused by an extract of cyanobacterium Microcystis aeruginosa bloom collected in the Manguaba Lagoon, Alagoas - Brazil

Abstract

Cyanobacteria (Microcystis aeruginosa), which produce powerful hepatotoxic cyclopeptides, were collected and submitted to the determination of toxicity through intraperitoneal injections made in 30 and 90 days-old Swiss albino mice. The liver and the spleen were histopathologically analyzed and the weight and vital signs development were monitored. Test of toxicity resulted in a LD 50 of 154.28 mg.Kg -1 . M. aeruginosa represented 95% of the analyzed biomass. The ratios between liver weight and body weight in the animal inoculated with a single dose were 6.0% and 7.2%, with multi doses 7.0% and 7.5% and in the control animals 4.0% and 5.0%, for adult and young animals, respectively. There was an accentuated increase in the volume and weight of the spleen, and the animals inoculated with a single dose showed a ratio between spleen weight and body weight of 0.67% and 0.37%, with multidoses 1.22% and 1.05% and the control animals the ratio was 0.12% and 0.15%, for adult and young animals, respectively. The young animals inoculated with single and multi doses had an increase of 150% and 407% in the spleen size while the adults increased, 607% and 845%, respectively, in relation to the control. The histopathological analysis showed strong differences in the structure of the hepatic parenchyme in control animals and in those exposed to the M. aeruginosa extract. The main alterations were the congestive aspect, including the sinusoid, and intrahepatic haemorrhagia. The histopathological analysis showed considerable increase in the number of multinuclear giant cells in the spleen of the animals intoxicated by M. aeruginosa.

A toxic cyanobacterial bloom in an urban coastal lake, Rio Grande do Sul state, Southern Brazil

“…According to Lawton et al (1994) classification, this bloom presented low toxicity; in general, the LD 50 toxicity values of Brazilian natural blooms containing microcystins ranged from 35.5 to 445.45 mg.kg -1 (25,29,33,40,47) and can be classified among the most toxic blooms. For the isolated strains of microcystin producers, the lowest LD 50 value is 13.7 mg.kg (Fig.…”

“…In Brazil, where these events are very frequent, the most common freshwater bloom forming genera are Microcystis, Anabaena, Aphanizomenon, Planktothrix, and Cylindrospermopsis, which is also the most studied cyanobacterial group (3,6,18,24,28,33,38,40,43,47).…”

A methodology for optimising the removal of cyanobacteria cells from a brazilian eutrophic water

“…The neurotoxins (anatoxin-a, homoanatoxin-a, anatoxin-a(s), saxitoxin and neosaxitoxin) act on the central nervous system, working as muscle blockers, and causing death by respiratory failure. The hepatotoxins include microcistins, nodularins and cilindrospermopsins, which produce symptoms such as weakness, paleness, cold extremities, breathlessness, vomiting and diarrhea, and can also cause death by respiratory failure, hepatic hemorrhage, and in some cases tumor apparition (Carmichael, 1994;Watanabe et al, 1996;Porfirio et al, 1999;Codd, 2000;Falconer, 2005).…”

Harmful phytoplankton blooms and fish mortality in a eutrophicated reservoir of northeast Brazil

“…The commonly encountered toxin producing species of cyanobacteria include Anabaena circinalis, Aphanizomenon flos-aquae, Microcystis aeruginosa, and Cylindrospermopsis raciborskii (Azevedo et al, 1994;Lagos et al, 1999). In Brazil, the toxic blooms of the cyanobacteria have been reported in the coastal lagoons (Azevedo, 1994;Porfirio et al, 1999;Magalhães et al, 2001;Lagos et al, 1999), in the estuaries (Matthiensen et al, 1999), and in the reservoirs (Bouvy et al, 2000;Chellappa et al, 2000). It has been reported that the presence of the microcystin toxin from the blooms of Microcystics aeroginosa in the water storage tank of a haemodialysis clinic resulted 53 deaths in Caruaru city, in the state of Pernambuco (Jochimson et al, 1998).…”