Skeletal and neurological risks demonstrated in zebrafish due to second-hand cigarette smoke and the neutralization of luteolin.

BACKGROUND: Cigarette smoke exposure poses significant health risks, including oxidative stress, inflammation, tissue damage, and neurodegenerative diseases. Luteolin, a natural flavonoid known for its antioxidant and anti-inflammatory properties, is of interest in countering these effects. AIM: This study aims to assess luteolin's protective potential against cigarette smoke extract (CSE) in adult zebrafish. MATERIALS AND METHODS: Adult zebrafish were exposed to CSE for 15 days, inducing smoke-related damage. Subsequent luteolin treatment assessed its impact. Evaluations included antioxidant enzymes (SOD, CAT), nitric oxide (NO), LDH activity (cellular damage), tissue integrity, fibrosis, amyloid plaque accumulation, and CSE component analysis via HPLC. KEY FINDINGS: CSE exposure heightened oxidative stress, reducing SOD and CAT activity and elevating NO levels, leading to cellular damage and tissue disruption, notably fibrosis and amyloid plaque accumulation. Inflammatory markers TNF-α and IL-1ß also increased. Luteolin treatment restored SOD and CAT activity, reduced LDH and NO activity, counteracting oxidative damage. It also mitigated fibrosis and reduced amyloid plaque deposition, preserving tissue integrity. Luteolin reduced TNF-α and IL-1ß levels and CSE components, displaying anti-inflammatory effects. SIGNIFICANCE: This study underscores luteolin's potential as a protective agent against cigarette smoke-induced harm in a zebrafish model.

Bacterial clearance and anti-inflammatory effect of Withaferin A against human pathogen of Staphylococcus aureus in infected zebrafish.

The emergence of antibiotic resistance is the most challenging factor for developing a proper drug to treat S. aureus infection. These bacterial pathogens can survive in fresh water and spread to various environments. Plant sources, especially pure compounds, are the material of interest amongst researchers for developing drugs of therapeutic value. Here, we report the bacterial clearance and anti-inflammatory potential of the plant compound Withaferin A, using the zebrafish infection model. The minimum inhibitory concentration of the Withaferin A was calculated as 80 µM against S. aureus. The DAPI/PI staining and scanning electron microscopy analysis showed the pore-forming mechanism of Withaferin A on the bacterial membrane. Along with the antibacterial activity, the results from the tube adherence test reveal the antibiofilm property of Withaferin A. In vivo studies were demonstrated to determine the effect of Withaferin A on survival, inflammatory response and behavioural changes during S. aureus infection. Staining zebrafish larvae with neutral red and Sudan black indicates a substantial decrease in the number of localized macrophages and neutrophils. The gene expression analysis showed the downregulation of inflammatory marker genes. Additionally, we observed the improvement in locomotory behaviour among Withaferin A treatment adult zebrafish. In conclusion, S. aureus can infect zebrafish and induces toxicological effect. In comparison, the results from in vitro and in vivo experiments suggest that Withaferin A can be used for synergistic antibacterial, antibiofilm and anti-inflammatory activity to treat infections due S. aureus.