Effects of vitamin B12 on the corneal nerve regeneration in rats.
The study was designed to investigate the effects of a new ophthalmic solution containing 0.05% vitamin B12 0.05% on corneal nerve regeneration in rats after corneal injury. Eyes of anesthetized male Wistar rats were subjected to corneal injury by removing the corneal epithelium with corneal brush (Algerbrush). After the epithelial debridement, the right eye of each animal received the instillation of one drop of the ophthalmic solution containing vitamin B12 0.05% plus taurine 0.5% and sodium hyaluronate 0.5% four time per day for 10 or 30 days. Left eyes were used as control and treated with solution containing taurine 0.5% and sodium hyaluronate 0.5% alone following the same regimen. Fluorescein staining by slit-lamp and morphological analysis was used to determine corneal wound healing. Immunohistochemistry, immunoblot and confocal microscopy were used to examine corneal re-innervation. Slit-lamp and histological analyses showed that re-epithelization of the corneas was accelerated in rats treated with vitamin B12. A clear-cut difference between the two groups of rats was seen after 10 days of treatment, whereas a near-to-complete re-epithelization was observed in both groups at 30 days. Vitamin B12 treatment had also a remarkable effect on corneal re-innervation, as shown by substantial increased in the expression of neurofilament 160 and β-III tubulin at both 10 and 30 days. The presence of SV2A-positive nerve endings suggests the presence of synapse-like specialized structures in corneal epithelium of the eye treated with vitamin B12. Our findings suggest that vitamin B12 treatment represents a powerful strategy to accelerate not only re-epithelization but also corneal re-innervation after mechanical injury.
Department of Pharmacy-Pharmacological Sciences, University of Bari, Via Orabona 4, Bari, Italy. Electronic address: mariarosariaromano@hotmail.com.
Maria Rosaria
MR
Romano
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy.
Francesca
F
Biagioni
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy.
Albino
A
Carrizzo
Ecclesiastical Authority Regional General Hospital Miulli, Acquaviva delle Fonti, BA, Italy.
Massimo
M
Lorusso
Department of Drug Sciences, University of Catania, Catania, Italy.
Angelo
A
Spadaro
Ecclesiastical Authority Regional General Hospital Miulli, Acquaviva delle Fonti, BA, Italy.
Tommaso
T
Micelli Ferrari
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy; Department of Medicine and Surgery, University of Salerno, Salerno, Italy.
Carmine
C
Vecchione
R&D Department, Alfa Intes, Casoria, NA, Italy.
Monia
M
Zurria
R&D Department, Alfa Intes, Casoria, NA, Italy.
Giuseppina
G
Marrazzo
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy.
Giada
G
Mascio
Department of Molecular Medicine, University "Sapienza", Roma, Italy.
Benedetto
B
Sacchetti
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy.
Michele
M
Madonna
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy; Department of Human Morphology and Applied Biology, University of Pisa, Pisa, Italy.
Francesco
F
Fornai
IRCSS, I.N.M., Neuromed, Pozzilli, IS, Italy; Department of Physiology and Pharmacology, University "Sapienza", Roma, Italy.
Ferdinando
F
Nicoletti
Department of Pharmacy-Pharmacological Sciences, University of Bari, Via Orabona 4, Bari, Italy.
Marcello Diego
MD
Lograno
D000818:Animals; D003315:Cornea / Q000294:innervation*; D065306:Corneal Injuries; D005131:Eye Injuries / Q000503:physiopathology*; D015590:Fluorophotometry; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D009416:Nerve Regeneration / Q000187:drug effects*; D016900:Neurofilament Proteins / Q000378:metabolism; D009882:Ophthalmic Nerve / Q000502:physiology*; D009883:Ophthalmic Solutions; D009994:Osmolar Concentration; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000494:pharmacology; D014404:Tubulin / Q000378:metabolism; D014805:Vitamin B 12 / Q000494:pharmacology*; D014803:Vitamin B Complex / Q000494:pharmacology*; D014949:Wounds, Nonpenetrating / Q000503:physiopathology*
D016900:Neurofilament Proteins; D009883:Ophthalmic Solutions; C488416:Tubb3 protein, rat; D014404:Tubulin; C061195:neurofilament protein M; D014803:Vitamin B Complex; D013654:Taurine; D014805:Vitamin B 12
SV2A; corneal injury; corneal nerve regeneration; neurofilament 160; vitamin B12; β-III tubulin