Abstract
OBJECTIVE: Doxorubicin (DOX) is widely used to treat various types of cancer. However, DOX treatment increases oxidative stress and causes other undesirable effects, such as cardiotoxicity, cognitive impairment, and death. Nicotine has been shown to inhibit DOX-induced cytotoxicity in vitro by activating nicotinic acetylcholine receptors. This study aimed to investigate whether combined treatment with varenicline, a partial agonist of nicotinic acetylcholine receptors, increased the survival rate of DOX-treated mice.
MATERIALS AND METHODS: Forty male albino mice were divided into four groups of 10. Control-group mice received a single intraperitoneal (i.p.) injection of 0.9% saline. The DOX group received a single dose of DOX (20 mg/kg body weight. i.p.). The varenicline group received varenicline daily in their drinking water at 0.1 mg/mL. The DOX+varenicline group received a single dose of DOX (20 mg/kg body weight, i.p.) and daily administration of varenicline in their drinking water (0.1 mg/mL). Mice were observed daily to evaluate the survival rate, and their body weight was recorded on alternate days.
RESULTS: All mice treated only with DOX died within 8 days. Co-administration of varenicline with DOX slightly improved the survival time and rate compared with the DOX-only group.
CONCLUSIONS: Combined treatment with varenicline and DOX may be useful for improving survival relative to treatment with DOX alone. This may be because varenicline is an alpha 7-nicotinic acetylcholine receptor agonist; however, further research into its precise mechanism of action is required.