Nutrient plasma levels achieved during treatment that reduces noise-induced hearing loss

Abstract

Hearing loss encompasses both temporary and permanent deficits. If temporary threshold shift (TTS) and permanent threshold shift (PTS) share common pathological mechanisms, then agents that reduce PTS should also reduce TTS. Several antioxidant agents have reduced PTS in rodent models; however, reductions in TTS have been inconsistent. This study first determined whether dietary antioxidants (beta-carotene, and vitamins C and E) delivered in combination with magnesium (Mg) reliably increase plasma concentrations of the active agents. Then, additional manipulations tested the hypothesis that these nutrients reduce acute TTS insult in the first 24 hours following loud sound, as well as longer lasting changes in hearing measured up to 7 days post-noise. Saline or nutrients were administered to guinea pigs prior to and after noise exposure. Sound-evoked electrophysiological responses were measured before noise, with tests repeated 1-hour post-noise, as well as 1-, 3-, 5-, and 7-days post-noise. All subjects showed significant functional recovery; subjects treated with nutrients recovered more rapidly, and had better hearing outcomes at early post-noise times as well as the final test time. Thus, this combination of nutrients, which produced significant increases in plasma concentrations of vitamins C and E and Mg, effectively reduced hearing loss at multiple post-noise times. These data suggest free radical formation contributes to TTS as well as PTS insults, and suggest a potential opportunity to prevent TTS in human populations.

Associations between dietary quality, noise, and hearing: Data from the National Health and Nutrition Examination Survey, 1999–2002

“…Pre-clinical studies have shown benefit for several molecules that can be obtained from normal healthy diets; some of these agents include beta-carotene, vitamins C and E, and magnesium (Le Prell et al, 2007a; Tamir et al, 2010; Le Prell et al, 2011a; Le Prell et al, 2011b), D-methionine (Campbell et al, 2007; Campbell et al, 2011; Clifford et al, 2011; Claussen et al, 2013; Lo et al, 2013; Rewerska et al, 2013), and N-acetylcysteine (Kopke et al, 2000; Kopke et al, 2005; Bielefeld et al, 2007; Kopke et al, 2007; Clifford et al, 2011). Ultimately, it may indeed be possible to prevent the secondary “spread” of damage that occurs with continued metabolic stress after noise stress.…”

Dietary Supplement Comprised of β-Carotene, Vitamin C, Vitamin E, and Magnesium: Failure to Prevent Music-Induced Temporary Threshold Shift

“…The current study assessed the potential prevention of TTS by a dietary supplement using this laboratory-based music exposure. The selection of the active agents within the dietary supplement was motivated by previous studies in mice and guinea pigs showing pre-noise dosing efficacy for NIHL and TTS prevention with the combination of β-carotene, vitamins C and E, and Mg [Le Prell et al, 2011a, b; Le Prell et al, 2007; Tamir et al, 2010]. …”

Activity of coenzyme Q10(Q-Ter multicomposite) on recovery time in noise-induced hearing loss

“…[31] The hearing threshold shift was evaluated 2 min after the end of exposure (TTS 2 ), then after 15 min (TTS 15 ) and 30 min (TTS 30 ). Subsequent measures were taken every 5 min until complete recovery.…”

“…[11,12] Magnesium has also been tested, alone or in compounds with other antioxidants (β-carotene, Vitamins E and C) with encouraging results. [13][14][15] Supra-physiological administration of Vitamin B12 appears to be effi cacious in protecting hearing, especially at the frequencies of 3 and 4 kHz. [16] Other studies have shown some effi cacy in preventing NIHL for glutathione precursors, such as N-acetylcysteine and methionine, or other antioxidants like alpha-lipoic acid.…”