Bogijetong decoction and its active herbal components protect the peripheral nerve from damage caused by taxol or nerve crush.

BACKGROUND: Bogijetong decoction (BGJTD) is a herbal drug formulation used in the traditional Asian medicine to treat neuropathic insults associated with diabetes and anticancer therapy. To understand the biological basis of BGJTD on protective effects against neuropathy, we investigated physiological and biochemical responses of the sciatic nerves deranged by taxol injection or crush injury in the rats. METHODS: Dissociated Schwann cells and neurons were prepared from the sciatic nerve and dorsal root ganglia (DRG) respectively and were treated with taxol and BGJTD. The sciatic nerve in the rat was injected with taxol or given crush injury. Animals were then administered orally with BGJTD. Effects of BGJTD treatment on cultured cells and in vivo sciatic nerves and DRG tissues were examined by immunofluorescence staining and western blot analysis. Sciatic nerve regeneration was assessed by histological observation using retrograde tracing technique and by behavioral hot plate test. Eighteen different herbal components of BGJTD were divided into 4 subgroups and were used to select herbal drugs that enhanced neurite outgrowth in cultured neurons. RESULTS: Morphological abnormalities in the sciatic nerve axons and DRG tissue caused by taxol injection were largely improved by BGJTD treatment. BGJTD treatment enhanced neurite outgrowth in cultured DRG neurons and improved Schwann cell survival. Phospho-Erk1/2 levels were elevated by BGJTD administration in the injured- or taxol-injected sciatic nerves. Vimentin phosphorylation catalyzed by cell division cycle 2 (Cdc2) kinase was induced from Schwann cells in the sciatic nerves after taxol injection and crush injury, and phospho-vimentin levels were further upregulated by BGJTD treatment. Retrograde tracing of DiI-labeled DRG sensory neurons revealed growth-promoting activity of BGJTD on axonal regeneration. A drug group (Be) composed of 4 active herbal components which were selected by neurite growth-enhancing activity was as effective as BGJDT for the recovery of thermal sensitivity of the hind paws which had been suppressed by taxol administration. CONCLUSIONS: These data suggest that BGJTD and its active herbal components may protects the peripheral nerve from damage caused by taxol injection and nerve crush.

Enhanced axonal regeneration of the injured sciatic nerve by administration of Buyang Huanwu decoction.

ETHNOPHARMACOLOGICAL RELEVANCE: Buyang Huanwu decoction (BYHWD) has been used in the traditional Chinese medicine for the treatment of cardiovascular and neurological symptoms, and recent experimental studies have begun to provide evidence showing its protective effects on neural cells. Yet, its function for the regenerative responses of axons in the peripheral nerve after injury is not known. AIM OF THE STUDY: The primary objective of the present study was to explore that BYHWD is involved in growth-promoting activity of the peripheral nerve axons after injury. We further examined whether the effect of BYHWD exerted directly on regrowing axons or Schwann cells. MATERIALS AND METHODS: Sciatic nerves in rats were given crush injury, and BYHWD was injected by oral administration. Sciatic nerves or DRG tissues were prepared for immunofluorescence staining and western blot analysis. Levels of axonal regeneration were quantified by retrograde tracing technique. Cultured DRG sensory neurons and Schwann cells were prepared from rats and used to examine the effects of BYHWD on the neurite outgrowth. Behavioral analysis on functional recovery after nerve injury was assessed in mice by pin prick test, adhesive removal test, and toe-spreading reflex. RESULTS: Immunofluorescence and retrograde tracing analyses showed that the distal extension of the sciatic nerve axons was significantly improved by BYHWD treatment. Levels of axonal growth-associated protein GAP-43 were upregulated by BYHWD treatment in the sciatic nerve after injury and in the neurites of cultured DRG neurons. In vivo administration of BYHWD in rats upregulated the induction level of cell division cycle 2 (Cdc2) and its phosphorylation of vimentin in Schwann cells from injured sciatic nerve. Coculture of DRG neurons with Schwann cells prepared from preinjured sciatic nerves in animals administered with BYHWD led to the enhancement in neurite outgrowth. Behavioral tests in mice given sciatic nerve injury showed a significant improvement in sensorimotor activity by BYHWD administration. CONCLUSIONS: Our results suggest that BYHWD administration into animals given sciatic nerve injury facilitates axonal regeneration by acting on both the axons undergoing regeneration and neighboring Schwann cells and improves functional recovery.

Induction of regenerative responses of injured sciatic nerve by pharmacopuncture therapy in rats.

Although recent studies report that combined treatment of herbal drugs with acupuncture can improve clinical efficacy in traditional oriental medicine, experimental evidence that supports this pharmacopuncture therapy is rare thus far. Here, we investigated the effects of the herbal drug recipe Sciatica 5 (SCTA5) and acupuncture stimulation on gall bladder 30 (GB30) on regenerative responses of injured sciatic nerve in rats. Treatment of cultured dorsal root ganglion (DRG) neurons with SCTA5 improved neurite outgrowth. In vivo regenerative responses, in terms of distal extension of regenerating axons and retrogradely-labeled DRG neurons, were improved by either injury site application of SCTA5 or GB30 acupuncture stimulation and further increased by SCTA5 pharmacopuncture on GB30 acupoint. Moreover, combined treatment of SCTA5 and GB30 was more effective than singular treatments in inducing Cdc2 kinase and accompanying vimentin phosphorylation in Schwann cells of the injured nerve. These results suggest that SCTA5 and GB30 therapies may be cooperative in facilitating axonal regeneration in the injured peripheral nerves.

Immune stimulatory effects of Loranthi ramulus on macrophages through the increase of NO and TNF-alpha.

The activation of macrophages by microorganisms plays an important role in host defense and immunopathology. Loranthi ramulus (LR) is commonly used as a traditional drug and health food in Korea. Here, we investigated the regulatory effects of LR on macrophage-mediated immune responses. Treatment of macrophages with LR resulted in the enhanced cell-surface expression of CD80, CD86 and major histocompatibility complex (MHC) class II, as well as the enhanced production of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha, and also iNOS and TNF-alpha mRNA expression. These alterations of LR-treated cells were associated with the activation of NF-kappaB and mitogen-activated protein kinases (MAPKs). LR increased the phosphorylation of MAPKs (JNK, ERK1/2, p38 MAPK) and the activation of NF-kappaB in Raw 264.7 cells. These results suggest that LR has increased NO and TNF-alpha production through phosphorylation of all three MAPKs following IkappaBalpha degradation and NF-kappaB activation. In conclusion, our results demonstrate that LR can effectively promote the activation of macrophages, suggesting that LR may possess the potential to regulate immune responses.

Toll-like receptor 4-mediated immunoregulation by the aqueous extract of Mori Fructus.

The aqueous extract of Mori Fructus (MF) exerts a change of phenotype and a cytoprotective effect in macrophages. The present study was carried out to investigate the immunomodulating activity of MF on the expression of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), co-stimulatory molecules and also interferon-gamma (IFN-gamma) in macrophages and splenocytes. Toll-like receptor 4 (TLR4) is a promising molecular target for immune-modulating drugs. It was hypothesized that one possible upstream signaling pathway leading to immunoregulation of MF may be mediated by TLRs. Multiple signaling molecules (NF-kappaB, ERK1/2, p38 and JNK) of the TLR4 signaling pathway were also detected. It was found that MF increased NO production and TNF-alpha secretion in RAW 264.7 and peritoneal macrophages, co-stimulatory molecules expression in peritoneal macrophages and IFN-gamma expression in splenocytes. Further studies indicated that MF could significantly induce the phosphorylation of signal molecules of MAPKs and the degradation of IkappaBalpha which finally led to the activation and nuclear translocation of nuclear factor-kappaB (NF-kappaB) for the target gene expression. All those notions disclosed that the aqueous extract MF is a new TLR4 activator, which induces a Th1 immune response as a consequence of induction of cytokines secretion, especially TNF-alpha and IFN-gamma.