Purpose: To investigate the antiproliferative and antimicrobial effects of cultivated Anabaena circinalis Rabenhorst Ex Bornet and Flahault [Synonym: Dolichospermum sigmoideum (Nygaard) Wacklin, L. Hoffmann and Komarek) and Nostoc entophytum Bornet and Flahault (Synonym: Nostoc paludosum Kützing ex Bornet and Flahault).
Methods: The algae extracts were prepared using 0.5 M Tris-HCL pH: 8.00, N-butanol, Ethanol and Dimethyl sulfoxide, and then tested on Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 7644, Escherichia coli O 157:H7, Pseudomonas aeruginosa ATCC 27853, Salmonella typhimurium CCM 5445, Candida albicans ATCC 10239 using the disc diffusion method in order to determine their antimicrobial effects. The anti-cancer activities of these two algae were tested against cancerous cell lines using BrdU cell proliferation ELISA method. The inhibition of these algae ethanol and butanol extracts were tested against Vero and HeLa carcinoma cells in concentrations of 100, 250 and 500 μg/mL.
Results: Anabaena circinalis (AC) and Nostoc entophytum (NE) antimicrobial properties against the tes organisms. The buffer extract obtained from AC showed the highest level of antimicrobial activity against L. monocytogenes ATCC 7644 while the buffer extract from NE displayed the highest antimicrobial activity against E. coli O 157:H7. The anti-proliferative data indicate that NE has effective anti-cancer properties. Furthermore, the results showed that cyanobacteria species were superior to DMSO and control groups in terms of anti-cancer activity in tumor cells. NE exhibited significant (p < 0.05) anti-proliferative effects at all three concentrations (100, 250, 500 μg/mL), compared to DMSO while AC exhibited significant anti-proliferative activity only at 500 μg/mL concentration (p < 0.01).
Conclusion: The results indicate that extracts possess antimicrobial and antiproliferative antivities. However, further studies are required to ascertain their clinical efficacy.