Cationic liposome-encapsulated carotenoids as a potential treatment for fibromyalgia in an animal model.

The present study investigated the efficacy of cationic liposome-encapsulated carotenoids (lutein or beta-carotene) as a treatment in an animal model of fibromyalgia (FM). Preparation and characterization of the nano-sized cationic liposomal carotenoids have been carried out. FM has been induced in the experimental animals via successive subcutaneous reserpine injection (1 mg/kg). Animals were divided into four groups; control, reserpinized (Res), reserpinized and cationic liposomal lutein-treated (Res + CL-Lut), and reserpinized and liposomal beta-carotene-treated (Res + CL-Bc). Levels of norepinephrine (NE), dopamine (DA), and serotonin (5-HT), and oxidative stress markers (MDA, H2O2, NO, and GSH) were determined in the brain's cortical tissue of the different groups of animals. Furthermore, the spectral analysis of the electrocorticogram (ECoG) was carried out. Animal behavior was tested for different animal groups. Results showed a significant reduction in monoamines, an elevation of oxidative stress markers, a shift in the ECoG frequency band power, and a change in pain threshold of the reserpinized animals. A return to a non-significant difference from the control values of all the measured parameters has been obtained after two weeks of cationic liposomal carotenoid preparations treatment. The present findings shed more light on the validity of the reserpine model of FM and provide evidence for the antidepressant, antioxidant, and anti-nociceptive potential of the cationic liposomal carotenoids. The present results proofed that the natural product preparations on a nano-sized scale could be a good alternative to the pharmacological interventions for FM treatment.