The paradox of cyanotoxins: from natural toxins to biotechnological resources

Cyanotoxins are highly toxic secondary metabolites produced by cyanobacteria that decrease water quality and exert a wide range of harmful effects on many organisms, including humans, through the food web. For many years, cyanotoxins were examined solely for their toxic effects; however, ongoing molecular biology, biochemistry, and applied biotechnology research on these metabolites has contributed to reframing them as valuable natural compounds in medicine, agriculture, and environmental biotechnology. Cyanotoxins exhibit anticancer, antimicrobial, allelopathic, and biopesticidal activities, providing promising opportunities for novel therapeutics, sustainable agriculture, and enhanced environmental remediation. Nevertheless, their high toxicity, potential harmful effects on non-target organisms, and environmental persistence necessitate comprehensive safety evaluations, environmental risk assessments, and the development of controlled application strategies. This review aims to highlight the ecological and biotechnological significance of cyanotoxins and seeks to stimulate further investigations into these natural metabolites as promising candidates for future sustainable technological developments.