Effect of Amiodarone on Rabbits' Optic Nerve and the Ameliorative Effect of Vitamin E: Ftir Study

Abstract

Objective: The study aimed to investigate the structural and conformational changes induced by short-term administration of the amiodarone in the optic nerve besides validating whether vitamin E coadministration with amiodarone will improve these changes. Methods: Thirty New Zealand white rabbits from both sexes were haphazardly categorized into three groups, whereas each group contains ten rabbits (20 eyes). One of these groups served as a control that received an intraperitoneal injection of normal saline. Rabbits in the second group intraperitoneally (ip) injected daily with 160 mg/kg body weight (bw) of amiodarone for two weeks. The last group orally administration 100 mg/kg bw of vitamin E with the 160 mg/kg bw of amiodarone ip daily for two weeks until the time of sacrifice. Fourier transform infrared spectroscopy (FTIR) analysis was conducted on the optic nerve of the all groups. Results: The results obtained from the FTIR spectrum revealed that the short-term administration of amiodarone caused a significant alteration in the stretching NH-OH region. A newly detected component centered at 3739±1 cm-1 was assigned as strO-H. There was a significant decrease (p˂0.05) in the bandwidth and band position of one component of strO-H that centered at 3598±1 cm-1. Moreover, remaining vibrational bands (O-Hasym and O-Hsym) were shifted to higher frequencies. Coadministration of vitamin E with amiodarone reduced the contour to four components as a control with significant increase in the band position of O-Hasym and the bandwidth of one component of str O-H. Amiodarone administrations lead to reducing the area ratio of asymCH2 to symCH2 and elevation of the area ratio of asymCH2 to asymCH3 while the coadministration of vitamin E returned it as the control ratio. The percentage of the β-turn was significantly increased while the α-helix content was decreased due to amiodarone. The contents of both components were considered mimicking the control values when Vitamin E was co-administered with amiodarone. Conclusion: The study stated that amiodarone could change the solubility and folding of the optic nerve proteins. Finally, vitamin E intake with amiodarone turns many of these changes induced by amiodarone to normal levels, which make it a good supplement for amiodarone users.