Abstract:
Cyanobacteria (blue-green algae) are photosynthetic prokaryotes usually found in eutrophicated water. Some strains of cyanobacteria are responsible for bloom formation and in the production of bioactive compounds such as toxins, antibacterial, antifungal, antiviral, etc. The present study is aimed at biochemical
analysis and tumourgenic activities of methanolic extracts of fresh water filamentatous heterocystous cyanobacteria isolated from the stagnant water body in the vicinity of Pilani, Jhunjhunu District of
Rajasthan. Methods: Isolation and cultivation of cyanobacteria was carried out by broth and plate culturing techniques in BG11 media. The cultures were incubated at 270C with illumination of 200 lux. The cells were harvested by centrifugation and were extracted with methanol. Toxins were partially purified by Thin-layer
chromatography and subjected to protein estimation by Lowery s methods. 100µg/kg of extract was injected by i.p in swiss albino mice daily for 28 days. Toxicity of the extract was further confirmed
by body weight analysis, biosopsy and TBARS assay of liver samples. Results: Tumors were observed in lower part of small intestine and colon in all animals. The results were further supported by bodyweight analysis and TBARS assay. Conclusion: The isolated strain of filamentous, heterocystous cyanobacteria found to have more amounts of toxic bioactive peptides that can cause colon tumors in mammalian models. The results of Lowey s methods and TLC showed the presence of toxic peptides which are dependent on
the nutritional factors such as nitrates in medium