Abstract
Chemotherapy-induced neuropathic pain is a debilitating and common side effect of cancer treatment. Mitochondrial dysfunction associated with oxidative stress in peripheral nerves has been implicated in the underlying mechanism. We investigated the potential of melatonin, a potent antioxidant that preferentially acts within mitochondria, to reduce mitochondrial damage and neuropathic pain resulting from the chemotherapeutic drug paclitaxel. In vitro, paclitaxel caused a 50% reduction in mitochondrial membrane potential and metabolic rate, independent of concentration (20-100 μmol/L). Mitochondrial volume was increased dose-dependently by paclitaxel (200% increase at 100 μmol/L). These effects were prevented by co-treatment with 1 μmol/L melatonin. Paclitaxel cytotoxicity against cancer cells was not affected by co-exposure to 1 μmol/L melatonin of either the breast cancer cell line MCF-7 or the ovarian carcinoma cell line A2780. In a rat model of paclitaxel-induced painful peripheral neuropathy, pretreatment with oral melatonin (5/10/50 mg/kg), given as a daily bolus dose, was protective, dose-dependently limiting development of mechanical hypersensitivity (19/43/47% difference from paclitaxel control, respectively). Melatonin (10 mg/kg/day) was similarly effective when administered continuously in drinking water (39% difference). Melatonin also reduced paclitaxel-induced elevated 8-isoprostane F2 α levels in peripheral nerves (by 22% in sciatic; 41% in saphenous) and limited paclitaxel-induced reduction in C-fibre activity-dependent slowing (by 64%). Notably, melatonin limited the development of mechanical hypersensitivity in both male and female animals (by 50/41%, respectively), and an additive effect was found when melatonin was given with the current treatment, duloxetine (75/62% difference, respectively). Melatonin is therefore a potential treatment to limit the development of painful neuropathy resulting from chemotherapy treatment.
Original language | English |
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Journal | Journal of Pineal Research |
Volume | 63 |
Issue number | 4 |
DOIs | |
Publication status | Published - 22 Aug 2017 |
Keywords
- Animals
- Antineoplastic Agents, Phytogenic/toxicity
- Antioxidants/pharmacology
- Cell Line, Tumor
- Female
- Humans
- Hyperalgesia
- Male
- Melatonin/pharmacology
- Mitochondria/drug effects
- Neuralgia/chemically induced
- Paclitaxel/toxicity
- Rats
- Rats, Sprague-Dawley
- 3ref2021