Growth-promoting Activity of Sanyak (Dioscoreae rhizoma) Extract on Injured Sciatic Nerve in Rats

Therapeutic Potential of Complementary and Alternative Medicines in Peripheral Nerve Regeneration: A Systematic Review

Despite the progressive advances, current standards of treatments for peripheral nerve injury do not guarantee complete recovery. Thus, alternative therapeutic interventions should be considered. Complementary and alternative medicines (CAMs) are widely explored for their therapeutic value, but their potential use in peripheral nerve regeneration is underappreciated. The present systematic review, designed according to guidelines of Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols, aims to present and discuss the current literature on the neuroregenerative potential of CAMs, focusing on plants or herbs, mushrooms, decoctions, and their respective natural products. The available literature on CAMs associated with peripheral nerve regeneration published up to 2020 were retrieved from PubMed, Scopus, and Web of Science. According to current literature, the neuroregenerative potential of Achyranthes bidentata, Astragalus membranaceus, Curcuma longa, Panax ginseng, and Hericium erinaceus are the most widely studied. Various CAMs enhanced proliferation and migration of Schwann cells in vitro, primarily through activation of MAPK pathway and FGF-2 signaling, respectively. Animal studies demonstrated the ability of CAMs to promote peripheral nerve regeneration and functional recovery, which are partially associated with modulations of neurotrophic factors, pro-inflammatory cytokines, and anti-apoptotic signaling. This systematic review provides evidence for the potential use of CAMs in the management of peripheral nerve injury.

Neuroprotective effects of Rhizoma Dioscoreae polysaccharides against neuronal apoptosis induced by in vitro hypoxia

Rhizoma Dioscoreae polysaccharides (RDPS) are the primary active ingredient of Rhizoma Dioscoreae, which is a traditional Chinese medicine. RDPS have previously been shown to scavenge reactive oxygen species, and protect against D-galactose-induced mimetic aging. The present study aimed to investigate the neuroprotective effects of RDPS against hypoxia-induced neuronal cell apoptosis. Neuronal cells harvested from pregnant Sprague-Dawley rats were divided into groups, as follows: i) Normal control group; ii) hypoxia-induced apoptosis neuronal cell model; iii) 0.025 g/l RDPS-treated group; iv) 0.05 g/l RDPS-treated group; v) 0.1 g/l RDPS-treated group; and vi) 0.25 g/l RDPS treated group. Neuronal cell viability was investigated using an MTT assay, and neuronal cell apoptosis was analyzed using Annexin V-fluorescein isothiocyanate/propidium iodide double-staining, Hoechst 33342 fluorescent staining, Rhodamine 123 staining, polymerase chain reaction and immunocytochemical staining. The RDPS-treated neuronal cells exhibited improved viability, and decreased hypoxia-induced mitochondrial injury and apoptosis. In addition, the mRNA and protein expression levels of caspase-3 and B-cell lymphoma (Bcl)-2-associated X protein (Bax) were significantly downregulated, whereas the mRNA and protein expression levels of Bcl-2 were significantly upregulated, in the RDPS-treated hypoxic neurons, as compared with the apoptosis model (P<0.05). Furthermore, the ratio of Bcl-2 expression:Bax expression significantly increased following RDPS treatment, as compared with the apoptosis model (P<0.05). The results of the present study suggested that RDPS may attenuate hypoxia-induced neuronal cell apoptosis by altering the expression levels of key apoptosis-regulating proteins in hypoxic neurons.

Effects of Dioscoreae Rhizoma (SanYak) on Peripheral Neuropathy and its Safety

Objectives:

This study aimed to evaluate the evidence available in the literature for the safety and efficacy of Dioscoreae Rhizoma(DR) for the treatment of peripheral neuropathy.

Methods:

Literature searches were performed in MEDLINE and three Korean medical databases up to April 2013. All studies evaluating the effects on peripheral neuropathy or the safety of DR monopreparations were considered.

Results:

Three studies - DR extract per os (po) on diabetic neuropathy in mice, DR extract injection on the peripheral sciatic nerve after crush injury in rats and DR extract injection to patients with peripheral facial paralysis proved that DR treatments were effective for the treatment of nerve injuries.

Conclusions:

In conclusion, we found the DR has a strong positive potential for the treatment of peripheral neuropathy, but studies addressing direct factors related to the nerve still remain insufficient.

Clinical research of the efficacy and the safety of dioscoreae rhizoma (sanyak) pharmacopuncture therapy for peripheral facial paralysis patients

OBJECTIVES

The aim of this study is to evaluate the efficacy and the safety of Sanyak pharmacopuncture therapy for the treatment of peripheral facial paralysis patients.

METHODS

This study was a retrospective investigation of a total of 70 patients who were inpatients of the Oriental Hospital of Daejeon University between January 1, 2011, and May 31, 2012, and who were diagnosed as having peripheral facial paralysis by physical examination, the patients received three different interventions. Eleven (11) patients were treated with acupuncture and alcohol Dioscorea rhizoma pharmacopuncture (ADG), 25 patients with acupuncture and distillation Dioscorea rhizoma pharmacopuncture (DDG), and 34 patients with acupuncture and non-Dioscorea rhizoma pharmacopuncture (NDG). The resulting data were analyzed.

RESULTS

The changed H-B grades indicated significant improvements in all three groups, and the ADG and the DDG groups showed significant results after two weeks of treatment when compared to the NDG group. The changed y-Scores indicated significant improvements in all three groups, and the ADG group showed significant results after 10 and 15 days of treatment when compared to the NDG group. Dioscorea rhizoma pharmacopuncture may be safe for the human body because in most cases, the only abnormal finding was the pain could by the application of pharmacopuncture.

CONCLUSIONS

The results of this study suggest that Oriental medical treatment with dioscoreae Rhizoma (Sanyak) pharmacopuncture complex therapy may be effective and safe in patient with peripheral facial paralysis.

Effect of Arecoline on Regeneration of Injured Peripheral Nerves

The present study provides in vitro and in vivo evaluation of arecoline on peripheral nerve regeneration. In the in vitro study, we found that arecoline at 50 μg/ml could significantly promote the survival and outgrowth of cultured Schwann cells as compared to the controls treated with culture medium only. In the in vivo study, we evaluated peripheral nerve regeneration across a 10-mm gap in the sciatic nerve of the rat, using a silicone rubber nerve chamber filled with the arecoline solution. In the control group, the chambers were filled with normal saline only. At the end of the fourth week, morphometric data revealed that the arecoline-treated group at 5 μg/ml significantly increased the number and the density of myelinated axons as compared to the controls. Immunohistochemical staining in the arecoline-treated animals at 5 μg/ml also showed their neural cells in the L4 and L5 dorsal root ganglia ipsilateral to the injury were strongly retrograde-labeled with fluorogold and lamina I–II regions in the dorsal horn ipsilateral to the injury were significantly calcitonin gene-related peptide-immunolabeled compared with the controls. In addition, we found that the number of macrophages recruited in the distal sciatic nerve was increased as the concentration of arecoline was increased. Electrophysiological measurements showed the arecoline-treated groups at 5 and 50 μg/ml had a relatively larger nerve conductive velocity of the evoked muscle action potentials compared to the controls. These results indicate that arecoline could stimulate local inflammatory conditions, improving the recovery of a severe peripheral nerve injury.

Ferulic Acid Enhances Peripheral Nerve Regeneration across Long Gaps

This study investigated the effect of ferulic acid (FA) on peripheral nerve injury. In the in vitro test, the effect of FA on viability of Schwann cells was studied. In the in vivo test, right sciatic nerves of the rats were transected, and a 15 mm nerve defect was created. A nerve conduit made of silicone rubber tube filled with FA (5 and 25 μg/mL), or saline (control), was implanted into the nerve defect. Results show that the number of proliferating Schwann cells increased significantly in the FA-treated group at 25 μg/mL compared to that in the control group. After 8 weeks, the FA-treated group at 25 μg/mL had a higher rate of successful regeneration across the wide gap, a significantly calcitonin gene-related peptide (CGRP) staining of the lamina I-II regions in the dorsal horn ipsilateral to the injury, a significantly diminished number of macrophages recruited, and a significantly shortening of the latency and an acceleration of the nerve conductive velocity (NCV) of the evoked muscle action potentials (MAPs) compared with the controls. In summary, the FA may be useful in the development of future strategies for the treatment of peripheral nerve injury.

Evaluation of the safety of Sanyak (Dioscoreae rhizoma) pharmacopuncture according to the extraction method: a double-blind randomized controlled trial

The study was conducted to evaluate the safety of Sanyak (Dioscoreae rhizoma) pharmacopuncture by injecting to healthy participants. Among the subjective symptoms, pain after the injection was statistically significant in the group injected with alcohol extract of Sanyak. The mean platelet volume and blood in the urinalysis after the injections were statistically significant between groups. After injections, the total protein level in liver function tests and hematocrit changed significantly. However, all of these changes were within normal limits, and Sanyak pharmacopuncture did not cause any severe physical responses or subjective symptoms and may, therefore, be considered safe.