European Journal of Biomedical and Pharmaceutical Sciences

ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF MARINE MACROALGAE COLLECTED FROM THE COASTLINE OF RAS AL KHAIMAH: TOWARDS GREEN PHARMACEUTICAL SOLUTIONS

*Vibha Bhardwaj

ABSTRACT

Numerous natural antimicrobial compounds have been identified in marine environments than in terrestrial. Marine organisms, like marine algae, are the source of structurally distinct natural products with biological, pharmacological, and nutraceutical properties. The current study examined the antibacterial and antioxidant properties of methanolic extracts from five different seaweed species: Ulva intestinalis (green), Padina gymnospora (brown), Sargassum vulgare (brown), Kappaphycus alvarezii (greenish brown), and Chondrus crispus (red). The DPPH radical scavenging assay was used to measure antioxidant activity, and Salmonella enterica, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis were used to measure antibacterial activity. At 1000 μg/ml, the maximum inhibition ranged from 65.19% to 68.20%, indicating dose-dependent radical scavenging activity in all seaweed extracts. Sargassum vulgare and Kappaphycus alvarezii exhibited the strongest DPPH scavenging properties among them. Species-specific inhibitory patterns were shown by antibacterial assays: Padina gymnospora was most effective against S. aureus (32 mm) and S. enterica (26 mm), while Ulva intestinalis showed the strongest activity against S. aureus (58 mm zone of inhibition). Interestingly, Sargassum vulgare exhibited broad-spectrum inhibition, especially against B. subtilis (19 mm) and E. coli (25 mm). The results support the potential use of these macroalgae in pharmaceutical and functional food applications by highlighting their therapeutic potential as natural sources of antioxidants and antibacterial agents.

Keywords: Marine macroalgae, Antioxidant activity, Antibacterial activity, Chondrus crispus, Kappaphycus alvarezii, Padina gymnospora, Sargassum vulgare, Ulva intestinalis, DPPH assay, Natural bioactive compounds.