Doxycycline attenuates peripheral inflammation in rat experimental autoimmune neuritis

Experimental autoimmune neuritis (EAN) is a T cell-mediated autoimmune inflammatory demyelinating disease of the peripheral nervous system and widely-used animal model of human inflammatory demyelinating polyradiculoneuropathies. Doxycycline is a well-known antibiotic and has been reported to have neuroprotective and anti-inflammatory effects. Here we investigated the effects of doxycycline on rat EAN. Therapeutic treatment with doxycycline (40 mg/kg body weight daily from the Day 9 to Day 14 post immunization) significantly attenuated the severity of EAN, decreased inflammatory infiltration of macrophages, B- and T-cells and demyelination in sciatic nerves of EAN rats. Pro-inflammatory molecules including matrixmetalloproteinase-9, inducible nitric oxide synthase and interleukin-17 were greatly decreased in sciatic nerves by administration of doxycycline as well. Taken together, our data showed that doxycycline could effectively suppress the peripheral inflammation to improve outcome of EAN, which suggests that doxycycline may be considered as a potential candidate of pharmacological treatment for neuropathies.