Protective effect of GCSB-5, an herbal preparation, against peripheral nerve injury in rats

GCSB-5 (traditional name: Chungpa-Juhn), an herbal medicine composed of 6 crude herbs (Saposhnikovia divaricata Schiskin, Achyranthis bidentata Blume, Acanthopanax sessiliflorum Seem, Cibotium baromets J. Smith, Glycine max Meriill, and Eucommia ulmoides Oliver), has been widely used in Asia for treatment of neuropathic and inflammatory diseases. This study investigated the protective effect of GCSB-5 against peripheral nerve injury in vitro and in vivo.

After left sciatic nerve transection, rats received oral administration of GCSB-5 (30, 100, 300, and 600 mg/kg), or saline (vehicle), respectively, once daily for 8 weeks. Motor functional recovery and axonal nerve regeneration were evaluated by measurement of sciatic functional index (SFI), sensory regeneration distance, and gastrocnemius muscle mass ratio. The myelinated axon number was counted by morphometric analysis. In the in vitro study, the effects of GCSB-5 on H(2)O(2)-induced oxidative damage in SH-SY5Y cells were investigated by measurement of cell viability, production of reactive oxygen species (ROS), lipid peroxidation, release of lactate dehydrogenease (LDH), and cellular glutathione contents. Neurite outgrowth was also determined.

After 8 weeks of nerve transection, SFI, regeneration distance, and gastrocnemius muscle mass ratio and myelinated axon number showed a significant decrease and these decreases were attenuated by GCSB-5. GCSB-5 significantly inhibited H(2)O(2)-induced cell death and oxidative stress, as evidenced by decreases in production of ROS and lipid peroxidation and release of LDH, and by increase in total GSH content.

The neuroprotective effect afforded by GCSB-5 is due in part to reduced oxidative stress.