Antioxidant and antibacterial activities of Cladophora glomerata (L.) Ktz. in Caspian Sea Coast, Iran

摘要

Cladophora?is one of the largest filamentous green-algal genus and has a widespread distribution in Caspian Sea Coast. This study aimed at assaying the antimicrobial and antioxidant activities of?Cladophora?glomerata?in South of Caspian sea. The antioxidant activity of the extract was investigated, including the total phenolic contents (3077 ± 105 mg gallic acid equivalent g-1?of extract), total flavonoid contents (595 ± 23 mg quercetin equivalent gl-1?of extract), scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (920 ± 42?mg ml-1?as IC50value), iron chelating activity (IC50?= 971 ± 39 μg ml-1), scavengers of nitric oxide (0.20 ± 0.01 mg ml-1?as IC50) and reducing power. There were significant differences between the extract and vitamin C (P<0.001). Furthermore, antimicrobial activities of the hydroalcoholic extracts of five different gram negative and positive bacteria including?Staphylococcus?aureus,?Bacillus?subtilis,Pseudomonas aeruginosa,?Salmonella?typhimurium?and?Proteus?mirabilis?were investigated. The extract was primarily screened for their possible antimicrobial effects using disc diffusion methods. The potential antibacterial activities at different concentrations of the extract were elucidated. The extract displayed a variable degree of antimicrobial activities on different bacteria. Among the gram positive bacteria, the?S.?aureus?(with wider zones of inhibition) was found to be more sensitive than?B. subtilis. Among the gram negative bacteria,?Salmonella enteritidiswas found to be more resistant than?Proteus??vulgaris. Our findings suggest the possibility of using the?Cladophora glomerata?as a novel source of natural antimicrobial and antioxidant agents for pharmaceutical industries.