Efficacy of topical Citrullus colocynthis (bitter apple) extract oil in chemotherapy-induced peripheral neuropathy: A pilot double-blind randomized placebo-controlled clinical trial.

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common complications in patients with cancer. Citrullus colocynthis (bitter apple) has been used in traditional Persian medicine as an effective pain relief, especially for neuralgia. We designed a pilot clinical trial to evaluate the safety and efficacy of topical C. colocynthis oil in management of CIPN in breast cancer patients. Thirty-four cancer patients with CIPN were randomly enrolled in two arms of a randomized, double-blind, placebo-controlled clinical trial. The patients were treated by topical C. colocynthis oil or placebo, two times per day for 2 months. Functional Assessment of Cancer Therapy/Gynecologic Oncology Group (FACT/GOG)-Neurotoxicity (Ntx) score was set as the primary outcome measure. No significant improvement was observed in the total score of FACT/GOG-Ntx scale (2.40 ± 1.90 vs. 1.05 ± 1.36, p = .879) in drug and placebo groups, respectively. There was also no significant improvement in the mean scores of FACT/GOG-Ntx in the sensory, motor, hearing, and functional domains in the two study groups. According to the results of this preliminary study, topical C. colocynthis oil failed to improve the symptoms of CIPN compared with placebo.