Bioactive Potential of Arthrospira platensis Ethanol Extract against ESBL and Biofilm-forming Meat Pathogens
R. K. Seethalakshmi
Department of Microbiology, RVS College of Arts and Science, Sulur, Coimbatore, Tamil Nadu, 641 402, India.
K. Rajeswari *
Department of Microbiology, RVS College of Arts and Science, Sulur, Coimbatore, Tamil Nadu, 641 402, India.
*Author to whom correspondence should be addressed.
Abstract
Foodborne bacterial pathogens associated with contaminated meat represent a significant public health concern due to antimicrobial resistance and biofilm formation. Therefore, investigating new antimicrobial substances to control foodborne pathogens is important for reducing potential food safety risks. In the present study, chicken, fish, and goat meat samples were collected and examined for the isolation and characterisation of bacterial pathogens. A total of 27 bacterial isolates representing seven genera were obtained, including Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Klebsiella pneumoniae, Proteus mirabilis, Citrobacter sp., and Salmonella sp. Among the isolates, 17 (62.9%) tested positive for extended-spectrum β-lactamase (ESBL) production, while 14 (51.9%) exhibited the ability to form biofilms. The antibacterial potential of Arthrospira platensis extracts was subsequently evaluated against the isolated foodborne pathogens. Preliminary phytochemical screening showed a higher number of phytochemical constituents in the ethanol extract than in the aqueous extract. Therefore, the ethanol extract was selected for further evaluation of its antibacterial, antioxidant, and anticancer activities. The ethanol extract exhibited concentration-dependent antibacterial activity, with the highest inhibition zone of 17 mm observed against E. coli at 10 mg/mL. DPPH radical-scavenging activity increased with extract concentration, reaching 79.78% at 1000 µg/mL, compared with 87.96% for ascorbic acid. In the MTT assay, HepG2 cell inhibition increased from 7.90% at 10 µg/mL to 74.06% at 250 µg/mL, with corresponding cell viabilities of 92.10% and 25.94%, respectively. The IC₅₀ values of the A. platensis extract were 118 µg/mL for antioxidant activity and 110 µg/mL for anticancer activity, respectively. Overall, the ethanol extract of A. platensis demonstrated antibacterial, antioxidant, and anticancer activities, indicating its potential as a source of bioactive compounds with promising applications in food safety and biomedical research.
Keywords: Arthrospira platensis, phytochemicals, antibacterial activity, antioxidant activity, HepG2 cells, cytotoxicity