Efficacy of vitamin A in experimentally induced acute otitis media.
ABSTRACT Vitamin A plays a role in the prevention of oxidative tissue damage. In the present study we investigated therapeutic role of this substance on healing of middle ear mucosa in experimental acute otitis media (AOM).
Otitis media was induced by inoculating Streptococcus pneumoniae via transtympanic injection. Thirty rats were divided into two groups. Group I treated with parenteral ampiciline-sulbactam. Group II received same antibiotic regimen and parenteral single dose of 100,000 IU vitamin A in palmitate form. At tenth day post-inoculation, animals were sacrificed and mucosal samples were excised from the infected tympanic cavities for histpathological examination and blood samples were obtained for measurements of activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and evaluation of levels of malondialdehyde (MDA) and nitric oxide (NO).
All the infected middle ear mucosas displayed various degrees of the inflammation, but there was no meaningful difference between two groups. However, epithelial integrity was significantly better in group II than group I (p<0.01). While serum NO and MDA levels decreased in the group receiving both antibiotic and vitamin A, serum SOD and GSH activity were found to increased. All of the statistical differences are significant.
Pretreatment with vitamin A increases antioxidant enzyme activities and reduces formation of NO and MDA. Vitamin A may be considered as an additional medicament for the medical treatment of AOM.