A New Topical Eye Drop Containing LyeTxI-b, A Synthetic Peptide Designed from A <i>Lycosa erithrognata</i> Venom Toxin, Was Effective to Treat Resistant Bacterial Keratitis
oleh: Carolina Nunes da Silva, Flavia Rodrigues da Silva, Lays Fernanda Nunes Dourado, Pablo Victor Mendes dos Reis, Rummenigge Oliveira Silva, Bruna Lopes da Costa, Paula Santos Nunes, Flávio Almeida Amaral, Vera Lúcia dos Santos, Maria Elena de Lima, Armando da Silva Cunha Júnior
| Format: | Article |
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| Diterbitkan: | MDPI AG 2019-04-01 |
Deskripsi
Bacterial keratitis is an ocular infection that can lead to severe visual disability. <i>Staphylococcus aureus</i> is a major pathogen of the eye. We recently demonstrated the strong antimicrobial activity of LyeTxI-b, a synthetic peptide derived from a <i>Lycosa erithrognatha</i> toxin. Herein, we evaluated a topical formulation (eye drops) containing LyeTxI-b to treat resistant bacterial keratitis. Keratitis was induced with intrastromal injection of 4 × 10<sup>5</sup> cells (4 µL) in New Zealand female white rabbits. Minimum inhibitory concentration (MIC) and biofilm viability were determined. LyeTxI-b ocular toxicity was evaluated through chorioallantoic membrane and Draize tests. One drop of the formulation (LyeTxI-b 28.9 µmol/L +0.5% CMC in 0.9% NaCl) was instilled into each eye four times a day, for a week. Slit-lamp biomicroscopy analysis, corneal histopathological studies and cellular infiltrate quantification through myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) detection were performed. LyeTxI-b was very effective in the treatment of keratitis, with no signs of ocular toxicity. Planktonic bacteria MIC was 3.6 µmol/L and LyeTxI-b treatment reduced biofilm viability in 90%. LyeTxI-b eliminated bacteria and reduced inflammatory cellular activity in the eyes. Healthy and treated animals showed similar NAG and MPO levels. LyeTxI-b is a potent new drug to treat resistant bacterial keratitis, showing effective antimicrobial and anti-inflammatory activity.