Multifunctional Antioxidants are Neuroprotective against Hearing Loss and Retinal Degeneration

P.F. Kador, R. Salvi, S. Fliesler, M. Pardue
Therapeutic Vision, Inc., Nebraska, United States

Keywords: light induced retinal degeneration, blast induced retinal degeneration, noise-induced hearing loss, gamma irradiation and UV light induced cataracts

Multifunctional Antioxidants (MFAOs) use the innovative therapeutic strategy that metal attenuating antioxidants targeting multiple mechanisms of radical action are superior to compounds that only bind transition metals or scavenge free radicals alone. MFAOs not only scavenge free radicals but also independently sequester and redistribute free transition metals that can participate in the Fenton generation of toxic hydroxyl radicals. In animal studies, they are orally active and achieve therapeutic levels in the lens, neural retina, brain, and now the inner ear. In rats, MFAOs reduce cataract formation induced by whole-head gamma irradiation, as well as diabetic ER stress and UV light. They also protect both the neural retina and photoreceptor layer against retinal degeneration induced by light in dark-adapted rats, and reduce amyloid beta plaque formation in the brain of Alzheimer’s transgenic mice. MFAOs also protect against manganese induced mitochondrial dysfunction. Recent studies also show that MFAOs prevent hearing loss in rats exposed to high intensity noise and appear to be protective against vision changes (spatial frequency and contrast sensitivity deficits, as well as motor coordination/vestibular deficits) induced by blast overpressure (acoustic blasts). Limited studies suggests that MFAOs have low toxicity (Maximum tolerated dose >1,800 mg/kg/day).