Biochemical and Histopathological Evaluation of The Effect of Thiamine Pyrophosphate on Favipiravir-İnduced Degenerative Corneal and Scleral Damage in Rats

Abstract

Introduction: Favipiravir causes ocular toxicity at high doses. Thiamine pyrophosphate (TPP) therapy can prevent ocular damage by reversing oxidative damage.

Objective: To investigate the ocular effect of favipiravir in rats and determine the protective effect of thiamine pyrophosphate (TPP) against the possible ocular toxicity of favipiravir.

Method: The rats were randomly divided into three groups; healthy control (HC), favipiravir administered (FAV), and TPP + favipiravir administered (TFAV). In the TFAV group, TPP was intraperitoneally injected at a dose of 25 mg/kg. In the HC and FAV groups, distilled water was applied as a solvent. One hour later, favipiravir was administered to the FAV and TFAV groups at 200 mg/kg orally by gavage twice a day. TPP was injected once a day. This procedure was repeated for one week. All rats were sacrificed under anesthesia, and the biochemical parameters and histopathological levels were analyzed.

Results: It was determined that the FAV group had higher blood MDA levels (p<0.001) and lower tGSH, SOD, and CAT levels (p<0.001) than the other groups. MDA levels of HC and TFAV groups were similar (p=0.407). It also inhibited the reduction in TPP, tGSH, SOD, and CAT (p<0.001). There was no significant difference between HC and TFAV groups regarding tGSH and CAT (p>0.05). In the histopathological examinations, severe collagen fiber degeneration and moderate hyperemia were observed in the corneal and scleral tissues in the FAV group.

Conclusion: The findings of the study showed that favipiravir caused damage to the cornea and sclera tissue through oxidative damage and TPP reduced this damage. Our study results suggest that TPP may be beneficial in Favipiravir-induced ocular toxicity.