Summary: Cyclic heptapeptides found in MICROCYSTIS and other CYANOBACTERIA. Hepatotoxic and carcinogenic effects have been noted. They are sometimes called cyanotoxins, which should not be confused with chemicals containing a cyano group (CN) which are toxic.

Top Publications

  1. Gaget V, Humpage A, Huang Q, Monis P, Brookes J. Benthic cyanobacteria: A source of cylindrospermopsin and microcystin in Australian drinking water reservoirs. Water Res. 2017;124:454-464 pubmed publisher
    ..These findings indicate that water quality monitoring programs need to consider benthic cyanobacteria as a potential source of toxins. ..
  2. Moon B, Kim T, Kim M, Choi J, Zoh K. Degradation mechanisms of Microcystin-LR during UV-B photolysis and UV/H2O2 processes: Byproducts and pathways. Chemosphere. 2017;185:1039-1047 pubmed publisher
    ..Meanwhile, the degradation by-products identified from MC-LR during UV-B/H2O2 process can be further degraded by increasing H2O2 dose. ..
  3. Dai G, Peng N, Zhong J, Yang P, Zou B, Chen H, et al. Effect of metals on microcystin abundance and environmental fate. Environ Pollut. 2017;226:154-162 pubmed publisher
    ..The results indicate that metals involved in MC transportation and degradation may play an important role in the environmental fate of MC. ..
  4. Gaget V, Lau M, Sendall B, Froscio S, Humpage A. Cyanotoxins: Which detection technique for an optimum risk assessment?. Water Res. 2017;118:227-238 pubmed publisher
  5. Zhang H, Dan Y, Adams C, Shi H, Ma Y, Eichholz T. Effect of oxidant demand on the release and degradation of microcystin-LR from Microcystis aeruginosa during oxidation. Chemosphere. 2017;181:562-568 pubmed publisher
    ..MC-LR, once released, was rapidly oxidized by permanganate resulting in only negligible buildup of extracellular toxins. ..
  6. Jiang X, Lee S, Mok C, Lee J. Sustainable Methods for Decontamination of Microcystin in Water Using Cold Plasma and UV with Reusable TiO? Nanoparticle Coating. Int J Environ Res Public Health. 2017;14: pubmed publisher
    b>Microcystins (MCs) are a family of cyanotoxins and pose detrimental effects on human, animal, and ecological health. Conventional water treatment processes have limited success in removing MCs without producing harmful byproducts...
  7. Wang J, Zhang L, Fan J, Wen Y. Impacts of Rac- and S-metolachlor on cyanobacterial cell integrity and release of microcystins at different nitrogen levels. Chemosphere. 2017;181:619-626 pubmed publisher
    ..Consequently, higher concentrations of metolachlor in source waters are harmful to humans, but it may prevent cyanobacterial blooms. However, the potential risks (e.g. build-up of extracellular toxins) should be considered. ..
  8. Kim Y, Kim W, Shin Y, Lee D, Kim Y, Kim J, et al. Microcystin-LR bioconcentration induces antioxidant responses in the digestive gland of two marine bivalves Crassostrea gigas and Mytilus edulis. Aquat Toxicol. 2017;188:119-129 pubmed publisher
    b>Microcystins (MCs) are a major group of potent cyanobacterial toxins found in freshwater and even brackish waterbodies...
  9. Dirren S, Pitsch G, Silva M, Posch T. Grazing of Nuclearia thermophila and Nuclearia delicatula (Nucleariidae, Opisthokonta) on the toxic cyanobacterium Planktothrix rubescens. Eur J Protistol. 2017;60:87-101 pubmed publisher
    ..The rigid structure of the cyanobacterial filaments and toxic secondary metabolites (e.g. microcystins) protect against diverse grazers...

More Information


  1. Altaner S, Puddick J, Wood S, Dietrich D. Adsorption of Ten Microcystin Congeners to Common Laboratory-Ware Is Solvent and Surface Dependent. Toxins (Basel). 2017;9: pubmed publisher
    Cyanobacteria can produce heptapetides called microcystins (MC) which are harmful to humans due to their ability to inhibit cellular protein phosphatases...
  2. Zhang L, Zhang H, Zhang H, Benson M, Han X, Li D. Roles of piRNAs in microcystin-leucine-arginine (MC-LR) induced reproductive toxicity in testis on male offspring. Food Chem Toxicol. 2017;105:177-185 pubmed publisher
    ..As far as we are aware, this is the first report showing that MC-LR could play a role in disorder of proliferative and cell apoptosis in the testis of the male offspring by the maternal transmission effect of toxicity. ..
  3. Miles C. Rapid and Convenient Oxidative Release of Thiol-Conjugated Forms of Microcystins for Chemical Analysis. Chem Res Toxicol. 2017;30:1599-1608 pubmed publisher
    b>Microcystins are potent cyclic heptapeptide toxins found in some cyanobacteria, and usually contain an ?,?-unsaturated carbonyl group that is readily conjugated to thiol-containing amino acids, peptides, and proteins in vivo and in vitro...
  4. Wang R, Li J, Jiang Y, Lu Z, Li R, Li J. Heterologous expression of mlrA gene originated from Novosphingobium sp. THN1 to degrade microcystin-RR and identify the first step involved in degradation pathway. Chemosphere. 2017;184:159-167 pubmed publisher
  5. Levizou E, Statiris G, Papadimitriou T, Laspidou C, Kormas K. Lettuce facing microcystins-rich irrigation water at different developmental stages: Effects on plant performance and microcystins bioaccumulation. Ecotoxicol Environ Saf. 2017;143:193-200 pubmed publisher
    This study investigated the microcystins (MCs)-rich irrigation water effect on lettuce of different developmental stages, i.e...
  6. Zhang W, Lin M, Wang M, Tong P, Lu Q, Zhang L. Magnetic porous ?-cyclodextrin polymer for magnetic solid-phase extraction of microcystins from environmental water samples. J Chromatogr A. 2017;1503:1-11 pubmed publisher
    b>Microcystins (MCs) are cyclic heptapeptide toxins and tumor promoters produced by cyanobacteria, which threaten the health of humans...
  7. Noyma N, de Magalhães L, Miranda M, Mucci M, Van Oosterhout F, Huszar V, et al. Coagulant plus ballast technique provides a rapid mitigation of cyanobacterial nuisance. PLoS ONE. 2017;12:e0178976 pubmed publisher
    ..The combined coagulant-ballast technique provides a promising alternative to algaecides in lakes, ponds and reservoirs. ..
  8. Chen Y, Huang X, Wang J, Li C. Effect of pure microcystin-LR on activity and transcript level of immune-related enzymes in the white shrimp (Litopenaeus vannamei). Ecotoxicology. 2017;26:702-710 pubmed publisher
    b>Microcystins (MCs) in freshwater and marine waters released by toxin-producing cyanobacteria have negative impacts to the aquatic environment...
  9. Chia M, Cordeiro Araújo M, Lorenzi A, Bittencourt Oliveira M. Cylindrospermopsin induced changes in growth, toxin production and antioxidant response of Acutodesmus acuminatus and Microcystis aeruginosa under differing light and nitrogen conditions. Ecotoxicol Environ Saf. 2017;142:189-199 pubmed publisher
    ..At 24h, higher microcystins content of M...
  10. García Espín L, Cantoral E, Asencio A, Aboal M. Microcystins and cyanophyte extracts inhibit or promote the photosynthesis of fluvial algae. Ecological and management implications. Ecotoxicology. 2017;26:658-666 pubmed publisher
    ..The effects of microcystins and cyanophyte extracts on the photosynthesis of the algae that belong to two taxonomic groups, Rhodophyta and ..
  11. Paerl H, Otten T. Environmental science. Blooms bite the hand that feeds them. Science. 2013;342:433-4 pubmed publisher
  12. Freeman K. Harmful algal blooms. Musty warnings of toxicity. Environ Health Perspect. 2010;118:A473 pubmed
  13. Lyu K, Zhang L, Gu L, Zhu X, Wilson A, Yang Z. Cladoceran offspring tolerance to toxic Microcystis is promoted by maternal warming. Environ Pollut. 2017;227:451-459 pubmed publisher
  14. Chiu Y, Chen Y, Wang T, Yen H, Lin T. A qPCR-Based Tool to Diagnose the Presence of Harmful Cyanobacteria and Cyanotoxins in Drinking Water Sources. Int J Environ Res Public Health. 2017;14: pubmed publisher
    ..are two common harmful cyanobacterial genera detected in freshwater lakes and reservoirs, with microcystins (MCs) and cylindrospermopsin (CYN) as their important metabolites, respectively...
  15. Haque F, Banayan S, Yee J, Chiang Y. Extraction and applications of cyanotoxins and other cyanobacterial secondary metabolites. Chemosphere. 2017;183:164-175 pubmed publisher
    ..It becomes evident that the potential for their use as biocides, chelators, biofuels, biofertilizers, pharmaceuticals, food and feed, and cosmetics has not yet been comprehensively studied or extensively implemented. ..
  16. Zheng C, Zeng H, Lin H, Wang J, Feng X, Qiu Z, et al. Serum microcystin levels positively linked with risk of hepatocellular carcinoma: A case-control study in southwest China. Hepatology. 2017;66:1519-1528 pubmed publisher
    b>Microcystins have been reported to be carcinogenic by animal and cell experimentation, but there are no data on the linkage between serum microcystins and hepatocellular carcinoma (HCC) risk in humans...
  17. Shuai Y, Lou D, Yin J, Qian X, Wang Y, Hong X, et al. Characterization of Microcystin-Induced Dualistic Toxic Effects on Primary Rat Hepatocytes. J Environ Pathol Toxicol Oncol. 2017;36:15-27 pubmed publisher
    b>Microcystins (MCs) comprise a group of widely characterized cyclic heptapeptides able to induce a series of liver injuries, including acute liver failure and primary liver cancer...
  18. Saoudi A, Brient L, Boucetta S, Ouzrout R, Bormans M, Bensouilah M. Management of toxic cyanobacteria for drinking water production of Ain Zada Dam. Environ Monit Assess. 2017;189:361 pubmed publisher
    ..The objective of this study is to monitor, detect, and identify the existence of cyanobacteria and microcystins during blooming times. Samples were taken in 2013 from eight stations...
  19. Zong W, Wang X, Du Y, Zhang S, Zhang Y, Teng Y. Molecular Mechanism for the Regulation of Microcystin Toxicity to Protein Phosphatase 1 by Glutathione Conjugation Pathway. Biomed Res Int. 2017;2017:9676504 pubmed publisher
    Glutathione (GSH) conjugation was an important pathway to regulate the toxicity of microcystins (MCs) targeted to protein phosphatases...
  20. Yan W, Li L, Li G, Zhao S. Microcystin-LR induces changes in the GABA neurotransmitter system of zebrafish. Aquat Toxicol. 2017;188:170-176 pubmed publisher
    It has been reported that exposure to microcystins altered adult zebrafish swimming performance parameters, but the possible mechanisms of action remain unknown...
  21. Sukenik A, Viner Mozzini Y, Tavassi M, Nir S. Removal of cyanobacteria and cyanotoxins from lake water by composites of bentonite with micelles of the cation octadecyltrimethyl ammonium (ODTMA). Water Res. 2017;120:165-173 pubmed publisher
    ..The complex efficiently removed cyanobacteria toxins with an exceptional high removal rate of microcystins. The effectiveness of the complex in elimination of cyanobacteria was further demonstrated with lake water ..
  22. Lin W, Hou J, Guo H, Qiu Y, Li L, Li D, et al. Dualistic immunomodulation of sub-chronic microcystin-LR exposure on the innate-immune defense system in male zebrafish. Chemosphere. 2017;183:315-322 pubmed publisher
    b>Microcystins (MCs), produced by toxic cyanobacterial blooms that appeared world wildly in eutrophication waters, have often caused fish illness and even massive death cases...
  23. Greer B, Maul R, Campbell K, Elliott C. Detection of freshwater cyanotoxins and measurement of masked microcystins in tilapia from Southeast Asian aquaculture farms. Anal Bioanal Chem. 2017;409:4057-4069 pubmed publisher
    ..mass spectrometry method was developed and validated for nine cyanotoxins across three classes including six microcystins, nodularin, cylindrospermopsin and anatoxin-a...