Antimicrobial Potentials of <i>Haliclona fibulata</i> Derived Compounds for Combatting Drug‐Resistant Bacterial Infections in Zebrafish Model

The rising threat of antimicrobial resistance among pathogens highlights the critical need for novel antimicrobial agents. This study explores the potential of natural products by investigating n-hexane extracts from the marine sponge Haliclona fibulata (HF) for their antibacterial efficacy. The well diffusion method of HF extract showed significant antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus with inhibition zones of 20 ± 0.66, 27 ± 0.58, and 22 ± 0.33 mm, respectively. Scanning electron microscopy investigations confirmed the disruptive impact of the extracts on bacterial cell morphology. Further investigations using P. aeruginosa-infected zebrafish model revealed that HF treatment improved survival rates in a dose-dependent manner. Additionally, oxidative stress and apoptosis were significantly reduced in the 100 µg/mL (HF100) treatment group, alongside downregulation of inflammatory markers such as il-1β, nf-kβ, tnf-α, and inos. Histological assessments showed reduced intestinal damage and fewer circulating macrophages in HF100-treated zebrafish larvae. Identifying potent bioactive compounds within the extracts suggests that HF could be a valuable source of natural antimicrobials, warranting further exploration for developing treatments against pathogenic infections.