Cylindrospermopsin

History

Human poisoning have been ascribed to cyanotoxins and of note is the incident at Palm Island, Queensland, Australia when 149 people were poisoned, mostly children, many of whom required hospitalisation. Victims were poisoned after drinking water from Solomon Dam that had been treated with copper sulfate to remove a persistent and heavy cyanobacterial bloom. It was subsequently shown that Cylindrospermopsis raciborskii (Woloszynska) isolated from Solomon Dam was hepatotoxic to mice when an isolate of freeze-dried cellular material was injected intraperitoneally.

Cylindrospermopsin

The toxin, cylindrospermopsin was later isolated from cultures of Cylindrospermopsis raciborskii. Subsequently, cylindrospermopsin was found in the cyanobacteria, Umezakia natans and Aphanizomenon ovalisporum. Cylindrospermopsin is an alkaloid with a tricyclic guanidine moiety bridged to hydroxymethyl uracil (Fig. 1). A deoxy- analog of cylindrospermopsin has been found in cultures of C. raciborskii. The hydroxyl group on the methyl uracil portion of the molecule is required for toxicity.

Figure 1. Structure of cylindrospermopsin

Toxicology of cylindrospermopsin

Acute toxicity of cylindrospermopsin in white mice via intraperitoneal injection ranges from an LD50 of 2mg/kg over 24hrs to 0.2 mg/kg over 5 days. Oral dosing with freeze-dried culture of C. raciborskii found the median lethal dose to white Swiss mice via this route is 6mg/kg cylindrospermopsin equivalent. Hepatotoxicity is the main toxic manifestation but extrahepatic lesions involving the kidney, heart and thymus has occurred in test animals. There can, at times, be considerable variability in the toxicity of cylindrospermopsin from different batches of C. raciborskii which is suggestive of other toxins in addition to cylindrospermopsin.

Water treatment for cylindrospermopsin elimination

The common presence of cylindrospermopsin in drinking water poses a public health problem especially in the more tropical regions of Australia. Treatment methods have been investigated in order to degrade the toxin. These include chlorination, ozonation and the use of UV photocatalysis. It has been shown that all of these techniques have the ability to degrade cylindrospermopsin but the formation of byproducts may be of concern if they remain toxic.

Suggested further reading

Chiswell RK, Shaw GR, Norris RL, Smith MJ, Seawright AA & Moore MR (1997) The cyanobacterium, Cylindrospermopsis raciborskii and its toxin, cylindrospermopsin. Aust. J. Ecotoxicol. 3, 17-23.

References

Banker, R, Carmeli, S., Hadas, O., Teltsch, B., Porat, R., and Sukenik, A., (1997) Identification of cylindrospermopsin in the cyanobacterium Aphanizomenon ovalisporum (Cyanophycaeae) isolated from Lake Kinneret, Israel J. Phycol. 33, 613-616.

Bourke ATC, Hawes RB, Neilson A & Stallman ND (1983) An outbreak of hepato-enteritis (The Palm Island mystery disease) possibly caused by algal intoxication. Toxicon Suppl. 3, 45-48.

Byth S (1980) Palm Island mystery disease. Med. J. Aust. 2, 40-42.

Falconer I, Hardy S, Humpage A, Froscio S, Tozer G, Hawkins P (1999) Hepatic and renal toxicity of the blue-green alga (cyanobacterium) Cylindrospermopsis raciborskii in male Swiss albino mice. Environ. Toxicol. 14, 143-150.

Harada K-I, Ohtani I, Iwamoto K, Suzuki M, Watanabe MF, Watanabe M & Terao K (1993) Isolation of cylindrospermopsin from a cyanobacterium Umezakia natans and its screening method. Toxicon 32: 73-84.

Hawkins PR, Runnegar MTC, Jackson ARB & Falconer IR (1985) Severe epatotoxicity caused by the tropical cyanobacterium (blue green alga) Cylindrospermopsis raciborskii (Woloszynska) seenaya and subba raju isolated from a domestic water supply reservoir. Appl. Environ. Microbiol. 50: 1292-1295.

Kuiper-Goodman T, Falconer IR & Fitzgerald J (1999) Human health aspects. In: Toxic Cyanobacteria in Water. A Guide to Their Public Health Consequences, Monitoring and Management, edited by I. Chorus, and J. Bartram (World Health Organisation. London) pp. 113-153.

Norris RL, Eaglesham GK, Pierens G, Shaw GR, Smith MJ, Chiswell RK, Seawright AA & Moore MR (1999) Deoxycylindrospermopsin, an analog of cylindrospermopsin from Cylindrospermopsis raciborskii. Environ. Toxicol. 14, 163-166.

Ohtani I, Moore RE & Runnegar MTC (1992) Cylindrospermopsin: A potent hepatotoxin from blue-green algae Cylindrospermopsis raciborskii. J. Amer. Chem.l Soc. 114: 7941-7942.

Seawright AA, Nolan CC, Shaw GR, Chiswell RK, Norris RL, Moore MR & Smith MJ (1999). The oral toxicity for mice of the tropical cyanobacterium Cylindrospermopsis raciborskii (Woloszynska). Environ. Toxicol. 14: 135-42.

Senogles PJ, Shaw GR, Smith MJ, Norris RL, Chiswell RK, Mueller J, Sadler R & Eaglesham GK (2000). Degradation of the cyanobacterial toxin, cylindrospermopsin from Cylindrospermopsis raciborskii by chlorination. Toxicon 38, 1203-1213.

Shaw GR, Sukenik A, Livne A, Chiswell RK, Smith MJ, Seawright AA, Norris RL, Eaglesham GK & Moore MR (1999) Blooms of the cylindrospermopsin containing cyanobacterium, Aphanizomenon ovalisporum (Forti) in newly constructed lakes, Queensland, Australia. Environ. Toxicol. 14: 167-178.

Terao K, Ohmori S, Igarashi K, Ohatani I, Watanabe MF, Harada K-I, Ito E, & Watanabe M (1994) Electron microscopic studies on experimental poisoning in mice induced by cylindrospermopsin isolated from blue-green alga Umezakia natans. Toxicon 32, 833-43.

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Page last updated - December 18, 2008

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