In Vitro Cytotoxicity and Antioxidative Potential of Nostoc Microscopicum (Nostocales, Cyanobacteria)

Abstract

Many cyanobacterial species (cyanoprokaryotes, blue-green algae) are potent producers of various secondary metabolites with low molecular weight and diverse biological activities (anti tumor, antimycotic, antiviral, antimicrobial, immunomodulatory, enzyme inhibition, cytotoxic activity). They have the potential to serve as convenient source of active substances for new medications and other commercial products. Therefore, cyanobacteria have become an object of intense scientific interest. New findings have shown that different cyanoprokaryotic species produce compounds with antioxidant activity. Also, there are reports for successful clinical trials using antitumor agents that contain active substances isolated from these organisms. On the other hand, it is well known that certain cyanobacteria produce toxins that could harm plants, animals and humans. Some cyanotoxins induce severe injuries even by contact with polluted water while washing or swimming. Hence, cyanotoxins production must be analyzed for all widely distributed cyanoprokaryotic species as well as those with potential application in medical practice. Certain species of the genus Nostoc are well known producers of substances with antitumor, enzyme inhibition, immunomodulatory, antioxidant or cytotoxic activities. However, little is known about the species Nostoc microscopicum. Therefore, the aim of the present study was to evaluate the antioxidant activity and potential cytotoxic effects of Nostoc microscopicum using extracts derived with different solvents. We show a moderate antioxidant activity of different Nostoc microscopicum extracts and prominent cytotoxic activity against several human cell lines (HeLa, FL, A549). Our results determine Nostoc microscopicum as interesting source of active compounds for pharmacology and biotechnology. In addition, this report presents for the first time an evidence for saxitoxins and microcystins production by Nostoc microscopicum and highlights the toxicological importance of this cyanobacterial species.