Effects of Herbal Bath "HAC" on Functional Recovery and c-Fos Expression in the Ventrolateral Periaqueductal Gray Region after Sciatic Crushed Nerve Injury in Rats

Peripheral nerve injuries are a commonly encountered clinical problem and often result in a chronic pain and severe functional deficits. c-Fos expression is sometimes used as a marker of increased neuronal activity. We have developed herbal bath "HAC" for pain control using the following herbs: Harpagophytum procumbens, Atractylodes japonica, and Corydalis tuber. In the present study, we investigated the effects of herbal bath "HAC" on the recovery rate of the locomotor function and the expression of c-Fos in the ventrolateral periaqueductal gray (vlPAG) region of brain following sciatic crushed nerve injury in rats. Walking track analysis for the evaluation of functional recovery and immunohistochemistry for the c-Fos expression were used for this study. In the present results, characteristic gait change with dropping of the sciatic function index (SFI) was observed and c-Fos expression in the vlPAG was suppressed following sciatic crushed nerve injury in rats. Immersion into herbal bath "HAC" enhanced SFI value and restored c-Fos expression in the vlPAG to the control value. These results suggest that herbal bath "HAC" might activate neurons in the vlPAG, and it facilitates functional recovery from peripheral nerve injury. Here we showed that herbal bath "HAC" could be used as a new therapeutic intervention for pain control and functional recovery from peripheral nerve injury.

Protective Effect of Shenqi-wan on Traumatic Brain Injury-induced Delayed Apoptosis in Rat Hippocampal Dentate Gyrus

Shenqi-wan, Oriental herbal medicine formulation, has been traditionally used for delayed mental and physical development in children, complications of diabetes, and glomerulonephritis. In the present study, the protective effect of the aqueous extract of Shenqi-wan against traumatic brain injury (TBI) in the rat hippocampal dentate gyrus was investigated. For this study, step-down avoidance task, terminal deoxynuclotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, Bax immunohistochemistry, and 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry were conducted. In the present results, it was shown that apoptotic cell death and cell proliferation in the dentate gyrus were significantly increased following TBI in rats and that the aqueous extract of Shenqi-wan suppressed the TBI-induced increase in apoptosis and cell proliferation in the dentate gyrus. Based on the present results, it is possible that the aqueous extract of Shenqi-wan has a neuroprotective effect on TBI-induced neuronal cell death.

Modulation of Amygdalin on Glycine- and Glutamate-induced Ion Currents in Rat Periaqueductal Gray Neurons

Amygdalin is known as vitamain B17, and it was called laetrile. Amygdalin is composed of two molecules of glucose, one molecule of benzaldehyde which induces an analgesic action, and one molecule of hydrocyanic acid which is an anti-neoplastic compound. Amygdalin had been used to treat cancers and relieve pain. In order to evaluate whether the analgesic action of amygdalin is related with descending pain control system, we performed patch clamp study. In the present study, the modulatory effects of amygdalin on glycine- and glutamate-induced ion currents in periaqueductal gray (PAG) neurons were investigated using the nystatin-perforated patch clamp method. Continuous application of lipopolysaccharides (LPS) on PAG neurons resulted in increased glycine-induced ion current, and in decreased glutamate-induced ion current. In contrast, continuous application of amygdalin with LPS resulted in decreased glycine-induced ion current increased by LPS, and increased glutamate- induced ion current decreased by LPS in concentration- and time-dependent fashion. These results demonstrate that amygdalin modulates neuronal activity of PAG by modulation of glycine and glutamate. Based on the present results, it can be suggested that amygdalin participates in the regulation of the descending pain control system in the level of PAG neurons. The present study demonstrated that activation of the descending pain control system is one of the possible analgesic mechanisms of amygdalin.