Ethoxyquin is an antioxidant which has been used in animal feed for many years and also an inhibitor of heat shock protein 90 (Hsp90).
Ethoxyquin (EQ) does not block Paclitaxel's (PTX's) ability to induce cell death in 4 different breast cancer cell lines. Results demonstrate that only when Hsp90 level is down regulated is neuroprotec-tion provided by Ethoxyquin (EQ) no longer seen[2]. It is found that Ethoxyquin provides neuroprotection with a best efficacy range from 30 to 300 nM. It is interesting to note that higher (μM) concentrations of Ethoxyquin do not provide further neuroprotection and in fact at these higher concentrations Ethoxyquin loses its neuroprotective effects[3].
Ethoxyquin (EQ) provides a dose-dependent neuroprotection. Although all 3 doses of Ethoxyquin provide partial neuroprotection against reduction in intraepidermal nerve fiber density, the peak efficacy is with the 75 μg/kg dose[2]. Rats treated with Ethoxyquin (EQ) alone or control vehicle treated rats gain weight as expected under normal physiological conditions[3].
[1]. Sadikot T, et al. Development of a high-throughput screening cancer cell-based luciferase refolding assay for identifying Hsp90 inhibitors. Assay Drug Dev Technol. 2013 Oct;11(8):478-88. [2]. Zhu J, et al. Ethoxyquin prevents chemotherapy-induced neurotoxicity via Hsp90 modulation. Ann Neurol. 2013 Dec;74(6):893-904. [3]. Zhu J, et al. Ethoxyquin provides neuroprotection against cisplatin-induced neurotoxicity. Sci Rep. 2016 Jun 28;6:28861.