Protective effects of Rutin against methanol induced acute toxic optic neuropathy: an experimental study

To determine the effects of Rutin on methanol induced optic neuropathy and compare the results with the effects of ethanol.

Totally 30 rats were divided into 5 groups, with 6 rats in each group as follows: healthy controls (C), methotrexate (MTX), methotrexate+methanol (MTM), methotrexate+methanol+ethanol (MTME) and methotrexate+ methanol+Rutin (MTMR). In all rabbits except those of the control group, MTX, diluted in sterile serum physiologic, 0.3 mg/kg per oral was applied for 7d by the aid of a tube. After this procedure to the rats of MTM, MTME and MTMR groups, 20% methanol with a dose of 3 g/kg per oral was given by the aid of a tube. In MTME group, 4h after the application of methanol, 20% ethanol was applied by the same way with a dose of 0.5 g/kg. On the other hand, in MTMR group 4h after the application of methanol, Rutin, which was dissolved in distilled water, was applied by the same way with a dose of 50 mg/kg.

There were statistically significant differences in tissue 8-hydroxy-2 deoxyguanine (8-OHdG), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), myeloperoxidase (MPO). glutathione peroxidase (tGSH) and superoxide dismutase (SOD) levels between groups (P<0.001). In MTMR group tissue 8-OHdG, IL-1β, MDA, and MPO levels were similar with the healthy controls but significantly different than the other groups. In histopathological evaluations, in MTX group there was moderate focal destruction, hemorrhage and decrease in number of astrocytes and oligodendrocytes; in MTM group there was severe destruction and edema with decrease in number of astrocytes and oligodendrocytes; in MTME group there was mild hemorrhage, mild edema, mildly dilated blood vessels with congestion while in MTMR group, optic nerve tissue was resembling the healthy controls.

Rutin may prevent methanol-induced optic neuropathy via anti-inflammatory effects and decreasing the oxidative stress. New treatment options are warranted in this disease to avoid loss of vision in patients.