EXPLORING THE PHARMACOLOGICAL POTENTIAL OF SYNECHOCOCCUS SP. PGDR2 THROUGH PHYTOCHEMICAL AND IN VITRO BIOACTIVITY STUDIES

Cyanobacteria are recognized as promising sources of bioactive compounds with pharmaceutical potential. The present study evaluated the phytochemical composition and biological activities of Synechococcus sp. PGDR2. Qualitative screening revealed the presence of tannins and proteins, while other major secondary metabolites were absent. Antioxidant activity assessed by DPPH and ABTS assays showed weak radical scavenging capacity with IC50 values >320 ug/mL. In contrast, ascorbic acid exhibited strong antioxidant activity with IC50 values of 19.97 ug/mL (DPPH) and 20.46 ug/mL (ABTS). Cytotoxicity against MG-63 osteosarcoma cells using the MTT assay demonstrated minimal growth inhibition, with an IC50 value >100 ug/mL, compared to doxorubicin (IC50 = 9.52 ug/mL). The anti-inflammatory activity evaluated by the protein denaturation assay showed moderate inhibition with an IC50 of 235.11 ug/mL, whereas diclofenac sodium exhibited an IC50 of 29.43 ug/mL.The comparatively high IC50 values suggest limited bioactivity of the crude extract. The observed anti-inflammatory potential may be attributed to tannins and proteinaceous compounds. Overall, Synechococcus sp. PGDR2 exhibited mild biological activity, indicating the need for further purification and LC MS profiling to identify potential bioactive constituents. These findings contribute to understanding the pharmacological potential of freshwater cyanobacteria.