Water-soluble pristine C(60) fullerenes attenuate isometric muscle force reduction in a rat acute inflammatory pain model

BACKGROUND: Being a scavenger of free radicals, C(60) fullerenes can influence on the physiological processes in skeletal muscles, however, the effect of such carbon nanoparticles on muscle contractility under acute muscle inflammation remains unclear. Thus, the aim of the study was to reveal the effect of the C(60) fullerene aqueous solution (C(60)FAS) on the muscle contractile properties under acute inflammatory pain. METHODS: To induce inflammation a 2.5% formalin solution was injected into the rat triceps surae (TS) muscle. High-frequency electrical stimulation has been used to induce tetanic muscle contraction. A linear motor under servo-control with embedded semi-conductor strain gauge resistors was used to measure the muscle tension. RESULTS: In response to formalin administration, the strength of TS muscle contractions in untreated animals was recorded at 23% of control values, whereas the muscle tension in the C(60)FAS-treated rats reached 48%. Thus, the treated muscle could generate 2-fold more muscle strength than the muscle in untreated rats. CONCLUSIONS: The attenuation of muscle contraction force reduction caused by preliminary injection of C(60)FAS is presumably associated with a decrease in the concentration of free radicals in the inflamed muscle tissue, which leads to a decrease in the intensity of nociceptive information transmission from the inflamed muscle to the CNS and thereby promotes the improvement of the functional state of the skeletal muscle.