Therapeutic Potential of Coastal Seaweed: In Vitro Pharmacological Evaluation of Ulva Prolifera as a Natural Source of Bioactive Compounds

Abstract

Ulva prolifera, a marine green alga and a promising natural source of bioactive compounds, is widely distributed across coastal regions worldwide, including the coastal ecosystems of Bangladesh. This study aimed to explore the therapeutic potential of U. prolifera collected from Char Kukri-Mukri and Char Montaz in Bangladesh by evaluating its antioxidant, anti-inflammatory, anticoagulant, antidiabetic, antibacterial, and cytotoxic properties. Antioxidant activity was evaluated using DPPH, H₂O₂ scavenging, reducing power, and ferric ion reducing assays, where ethanolic and aqueous extracts showed moderate activity (DPPH IC₅₀: 317.22 µg/mL and 447.82 µg/mL). The aqueous extract demonstrated higher anti-inflammatory effects through 15-lipoxygenase inhibition and membrane stabilization assay. Anticoagulant effects were confirmed by serine protease inhibition and increased prothrombin time. In antidiabetic assays, both extracts showed relatively stronger α-amylase inhibitory activity. Antibacterial assays revealed the ethanolic extract was more effective, particularly against E. coli and S. aureus. Cytotoxicity evaluation using the brine shrimp lethality assay indicated low toxicity for both extracts (LC₅₀ >100 µg/mL). GC-MS analysis identified 26 bioactive compounds, highlighting the chemical richness of the extracts. These findings suggest that U. prolifera may serve as a potential resource for developing natural therapeutics and nutraceuticals.