Antimycobacterial and cytotoxicity activity of microcystins

Abstract

BackgroundThe present work aimed to evaluate the antimycobacterial activity and cytotoxicity of Microcystis aeruginosa toxins, the MC-LR variant and purified extract of [D-Leu1] microcystin-LR.MethodsThe antimicrobial activity of M. aeruginosa extract and microcystin was evaluated by resazurin microtiter assay against Mycobacterium tuberculosis, M. terrae, M. chelonae and M. kansasii. The cytotoxicity assay was performed by trypan blue exclusion against the HTC cell line.ResultsAntimicrobial activity was observed in the hexanic extract of M. aeruginosa (RST 9501 strain) against M. tuberculosis, including sensitive and resistant strains with minimal inhibitory concentrations (MIC) between 1.93 μM and 0.06 μM. The high activity of M. aeruginosa hexanic extract could be attributed to the major presence of the toxins MC-LR and [D-Leu1] MC-LR that showed activity at MIC between 53 and 0.42 μM against tested mycobacterial strains. Even at the highest concentration tested, no toxicity of M. aeruginosa extracts was identified against HTC cells.ConclusionsThese preliminary results suggest that [D-Leu1] MC-LR is a promising candidate for the development of a new antimycobacterial agent.

Microcystins production and antibacterial activity of cyanobacterial strains of Synechocystis, Synechococcus and Romeria isolated from water and coral reef organisms of Brazilian coast

“…Carmichael and Li (2006) reported the production of microcystins by a marine Synechococcus from Salton Sea, and observed that microcystins may show a more common occurrence in marine environments. Some toxins have promising anticancer, antimycobacterial or other anti-disease activities (Gerwick et al, 2008;Ramos et al, 2015). In our work we detected the microcystins by ELISA technique in the strains of S. aquatilis and Synechocystis spp., and the mcyB gene was detected in only one of these strains.…”

“…Additionally, the antibacterial and antifungal activity of cyanobacteria exometabolites has been previouly reported by Volk and Furkert (2006) and Ramos et al (2015). In this work, we isolated and identified the cyanobacteria belonging to the genera Synechocystis, Synechococcus and Romeria from seawater and reef benthic invertebrates (sponges, corals and ascidians) from the Brazilian Northeastern coast and we evaluated their capacity for microcystin production and antibacterial activity.…”

Advances in the Biotechnological Potential of Brazilian Marine Microalgae and Cyanobacteria

“…Ramos et al [ 94 ] evaluated a variant of microcystin that showed antimicrobial activity against mycobacteria. Some strains of Mycobacterium tuberculosis are known to cause tuberculosis in humans.…”

Identification of Non-tuberculous mycobacteria isolated from patients at Teaching Hospitals, Kandy and Peradeniya

“…5 Non-tuberculous mycobacteria are known to cause localized or disseminated infections based on local predisposition and /or degree of immunity. 6 Due to the ubiquitous existence of NTMs in the environment, identifying a causative relationship is dependent on appropriate sampling and strict laboratory practices, as contamination should be excluded. 6 It is likely that the incidence of NTM infections will increase in the future.…”

“…6 Due to the ubiquitous existence of NTMs in the environment, identifying a causative relationship is dependent on appropriate sampling and strict laboratory practices, as contamination should be excluded. 6 It is likely that the incidence of NTM infections will increase in the future. 1 The aim of this study was to determine the proportion and phenotypic/genotypic identification of NTM among mycobacterial clinical isolates obtained from patients presenting with pulmonary and extrapulmonary diseases at Teaching Hospitals, Kandy and Peradeniya.…”