Daijiworld Media Network – New Delhi
New Delhi, Dec 18: In a major scientific breakthrough, researchers from the Bose Institute, Kolkata, have developed a novel peptide-based therapy that shows strong potential in treating fungal keratitis — a severe and sight-threatening infection of the cornea, the transparent front layer of the eye.
The research team, in collaboration with scientists from the L V Prasad Eye Institute, Hyderabad, designed a 15-residue peptide named SA-XV, derived from the host-defence peptide S100A12. The peptide, earlier known for its antifungal properties, has now been extensively characterised for its potency and precise mechanism of action.
The study, published in the Journal of Biological Chemistry, highlights SA-XV as a promising alternative to existing antifungal drugs, offering effective treatment with significantly reduced side effects.
Fungal keratitis is increasingly being described as a “slow epidemic” in India, affecting a large population, especially those engaged in agriculture. Improper contact lens hygiene and overuse of lenses further contribute to the rising number of corneal infections.
At present, amphotericin B is the primary drug used to treat fungal eye infections. However, its clinical use is restricted due to serious side effects, including kidney damage and high haemolytic activity that leads to rapid destruction of red blood cells. This has created an urgent need for safer and more effective antifungal therapies.
In experimental mouse models, SA-XV demonstrated a marked reduction in the severity of fungal keratitis. According to Professor Anirban Bhunia of Bose Institute, who led the study, the antimicrobial peptide is non-toxic, stable in serum, and effective against both free-floating and biofilm forms of Fusarium and Candida species.
Explaining its mechanism, the researchers said SA-XV initially interacts with the fungal cell wall and plasma membrane before entering the cell. It then accumulates in the cytoplasm, localises in the nucleus where it binds to genomic DNA and disrupts the cell cycle, and finally targets the mitochondria, triggering fungal cell death through apoptosis.
Importantly, the study also notes that SA-XV not only acts as a powerful antifungal agent but also promotes corneal wound healing, making it a dual-action therapeutic option.
The researchers believe that SA-XV could emerge as a novel and safer treatment for fungal keratitis, offering hope for improved vision outcomes and faster recovery, while reducing dependence on existing drugs with harmful side effects.