The purpose of this study was to analyze and compare cytokine and growth factor levels in modified autologous conditioned serum (mACS) and autologous serum (AS) and to evaluate their therapeutic effec Show more
The purpose of this study was to analyze and compare cytokine and growth factor levels in modified autologous conditioned serum (mACS) and autologous serum (AS) and to evaluate their therapeutic effects in a benzalkonium chloride (BAK)-induced murine dry eye model. Serum samples were obtained from twenty healthy volunteers and analyzed by ELISA. A dry eye model was established in twenty-four C57BL/6 mice by topical application of 0.2% BAK twice daily for seven days. The mice were evenly divided into three subgroups: saline-treated, 0.5% AS-treated, and 0.5% mACS-treated. The right eyes were treated, and the left eyes served as untreated controls. Eyeballs were harvested on days 7 and 14 for immunofluorescence staining. Results showed that neuroprotective factors (BDNF and fractalkine), pro-inflammatory cytokines (IL-1β, IL-6, MIF, TNF-α), and VEGF-A were significantly elevated in the mACS group, whereas PDGF-BB was significantly reduced. Furthermore, immunofluorescence analysis demonstrated a significantly greater recovery of central corneal nerve fibers in the mACS-treated group compared with the saline group at day 7 (p < 0.01). At day 14, the mACS-treated group continued to show a trend toward increased central corneal nerve regeneration, although this difference did not reach conventional statistical significance (p < 0.1). No significant differences were observed between the AS- and saline-treated groups. In conclusion, compared with AS, mACS demonstrates a cytokine profile suggestive of enhanced neuroprotective potential and may facilitate corneal nerve regeneration in the BAK-induced murine dry eye model. Show less
Sensory neurotoxicity involves damage to the sensory nerves, often resulting from exposure to chemicals, medications, toxins, infections, or neurological disorders. Benzalkonium chloride (BKC) is a wi Show more
Sensory neurotoxicity involves damage to the sensory nerves, often resulting from exposure to chemicals, medications, toxins, infections, or neurological disorders. Benzalkonium chloride (BKC) is a widely used quaternary ammonium compound with antiseptic properties, commonly present in pharmaceuticals, household products, and cosmetics. While the potential neurotoxicity of BKC has been previously explored in ocular and nasal epithelia, its impact on other sensory systems and the underlying mechanisms remain largely unclear. In this study, we used zebrafish (Danio rerio) embryos to assess the developmental neurotoxicity of BKC. Embryonic exposure to 0.72, 1.28, and 2.24 mg/L BKC led to dose-dependent impairments in mechanosensory hair cells, reduced startle responses, and heightened nociceptive sensitivity upon noxious stimulation. BKC exposure induced pronounced oxidative stress, evidenced by increased reactive oxygen species levels, reduced antioxidant enzyme activity, and altered expression of redox-regulating genes. Moreover, BKC significantly upregulated inflammatory and pain-associated genes, including tnfa, il1b, cox2, bdnf, and trpa1b. Expression profiling of hair cell differentiation markers revealed increased pou4f3 and decreased tmc2a/tmc2b, suggesting that BKC disrupts both terminal differentiation and mechanotransduction processes in sensory hair cells. Collectively, these findings uncover a novel mechanistic link between oxidative stress, impaired hair-cell maturation, and sensory dysfunction, offering new insights into the mechanisms underlying BKC-induced sensory neurotoxicity. This study emphasizes the ecological and toxicological relevance of quaternary ammonium compounds in aquatic environments. Show less