Diosgenin Exerts Analgesic Effects by Antagonizing the Selective Inhibition of Transient Receptor Potential Vanilloid 1 in a Mouse Model of Neuropathic Pain.

Diosgenin is a botanical steroidal saponin with immunomodulatory, anti-inflammatory, anti-oxidative, anti-thrombotic, anti-apoptotic, anti-depressant, and anti-nociceptive effects. However, the effects of diosgenin on anti-nociception are unclear. Transient receptor potential vanilloid 1 (TRPV1) plays an important role in nociception. Therefore, we investigated whether TRPV1 antagonism mediates the anti-nociceptive effects of diosgenin. In vivo mouse experiments were performed to examine nociception-related behavior, while in vitro experiments were performed to examine calcium currents in dorsal root ganglion (DRG) and Chinese hamster ovary (CHO) cells. The duration of capsaicin-induced licking (pain behavior) was significantly reduced following oral and intraplantar administration of diosgenin, approaching levels observed in mice treated with the TRPV1 antagonist N-(4-tertiarybutylphenyl)-4-(3-cholorphyridin-2-yl) tetrahydropyrazine-1(2H)-carbox-amide. Additionally, oral administration of diosgenin blocked capsaicin-induced thermal hyperalgesia. Further, diosgenin reduced capsaicin-induced Ca2+ currents in a dose-dependent manner in both DRG and CHO cells. Oral administration of diosgenin also improved thermal and mechanical hyperalgesia in the sciatic nerve constriction injury-induced chronic pain model by reducing the expression of TRPV1 and inflammatory cytokines in DRG cells. Collectively, our results suggest that diosgenin exerts analgesic effects via antagonism of TRPV1 and suppression of inflammation in the DRG in a mouse model of neuropathic pain.

Stem Cell Therapy for Modulating Neuroinflammation in Neuropathic Pain.

Neuropathic pain (NP) is a complex, debilitating, chronic pain state, heterogeneous in nature and caused by a lesion or disease affecting the somatosensory system. Its pathogenesis involves a wide range of molecular pathways. NP treatment is extremely challenging, due to its complex underlying disease mechanisms. Current pharmacological and nonpharmacological approaches can provide long-lasting pain relief to a limited percentage of patients and lack safe and effective treatment options. Therefore, scientists are focusing on the introduction of novel treatment approaches, such as stem cell therapy. A growing number of reports have highlighted the potential of stem cells for treating NP. In this review, we briefly introduce NP, current pharmacological and nonpharmacological treatments, and preclinical studies of stem cells to treat NP. In addition, we summarize stem cell mechanisms-including neuromodulation in treating NP. Literature searches were conducted using PubMed to provide an overview of the neuroprotective effects of stem cells with particular emphasis on recent translational research regarding stem cell-based treatment of NP, highlighting its potential as a novel therapeutic approach.

Dexmedetomidine Inhibits Voltage-Gated Sodium Channels via α2-Adrenoceptors in Trigeminal Ganglion Neurons.

Dexmedetomidine, an α2-adrenoceptor agonist, is widely used as a sedative and analgesic agent in a number of clinical applications. However, little is known about the mechanism by which it exerts its analgesic effects on the trigeminal system. Two types of voltage-gated sodium channels, Nav1.7 and Nav1.8, as well as α2-adrenoceptors are expressed in primary sensory neurons of the trigeminal ganglion (TG). Using whole-cell patch-clamp recordings, we investigated the effects of dexmedetomidine on voltage-gated sodium channel currents (INa) via α2-adrenoceptors in dissociated, small-sized TG neurons. Dexmedetomidine caused a concentration-dependent inhibition of INa in small-sized TG neurons. INa inhibition by dexmedetomidine was blocked by yohimbine, a competitive α2-adrenoceptor antagonist. Dexmedetomidine-induced inhibition of INa was mediated by G protein-coupled receptors (GPCRs) as this effect was blocked by intracellular perfusion with the G protein inhibitor GDPß-S. Our results suggest that the INa inhibition in small-sized TG neurons, mediated by the activation of Gi/o protein-coupled α2-adrenoceptors, might contribute to the analgesic effects of dexmedetomidine in the trigeminal system. Therefore, these new findings highlight a potential novel target for analgesic drugs in the orofacial region.

Optimization of air-blast drying process for manufacturing Saccharomyces cerevisiae and non-Saccharomyces yeast as industrial wine starters.

Wine yeast (Saccharomyces cerevisiae D8) and non-Saccharomyces wine yeasts (Hanseniaspora uvarum S6 and Issatchenkia orientalis KMBL5774) were studied using air-blast drying instead of the conventional drying methods (such as freeze and spray drying). Skim milk-a widely used protective agent-was used and in all strains, the highest viabilities following air-blast drying were obtained using 10% skim milk. Four excipients (wheat flour, nuruk, artichoke powder, and lactomil) were evaluated as protective agents for yeast strains during air-blast drying. Our results showed that 7 g lactomil was the best excipient in terms of drying time, powder form, and the survival rate of the yeast in the final product. Finally, 7 types of sugars were investigated to improve the survival rate of air-blast dried yeast cells: 10% trehalose, 10% sucrose, and 10% glucose had the highest survival rate of 97.54, 92.59, and 79.49% for S. cerevisiae D8, H. uvarum S6, and I. orientalis KMBL5774, respectively. After 3 months of storage, S. cerevisiae D8 and H. uvarum S6 demonstrated good survival rates (making them suitable for use as starters), whereas the survival rate of I. orientalis KMBL5774 decreased considerably compared to the other strains. Air-blast dried S. cerevisiae D8 and H. uvarum S6 showed metabolic activities similar to those of non-dried yeast cells, regardless of the storage period. Air-blast dried I. orientalis KMBL5774 showed a noticeable decrease in its ability to decompose malic acid after 3 months of storage at 4 °C.

Serious Adverse Transfusion Reactions Reported in the National Recipient-Triggered Trace Back System in Korea (2006-2014).

BACKGROUND: Adverse transfusion reactions (ATRs) are clinically relevant to patients with significant morbidity and mortality. This study aimed to review the cases of ATR reported in the recipient-triggered trace back system for a recent nine-year period in Korea. METHODS: Nine-year data obtained from 2006 to 2014 by the trace back system at the Division of Human Blood Safety Surveillance of the Korean Centers for Disease Control (KCDC) were reviewed. The suspected cases were assessed according to six categories: (i) related to, (ii) probably related to, (iii) probably not related to, (iv) not related to transfusion, (v) unable to investigate, and (vi) under investigation. RESULTS: Since 2006, 199 suspected serious ATRs were reported in hospitals and medical institutions in Korea, and these ATRs were reassessed by the division of Human Blood Safety Surveillance of the KCDC. Among the reported 193 cases as transfusion related infections, hepatitis C virus (HCV) infection (135, 67.8%) was reported most frequently, followed by hepatitis B virus (HBV) infection (27, 13.6%), HIV infection (13, 6.5%), syphilis (9, 4.5%), malarial infection (4, 2.0%), other bacterial infections (3, 1.5%), HTLV infection (1, 0.5%), and scrub typhus infection (1, 0.5%), respectively. Of the 199 cases, 13 (6.5%) cases were confirmed as transfusion-related (3 HCV infections, 3 malarial infections, 1 HBV infection, 2 Staphylococcus aureus sepsis, 3 transfusion-related acute lung injuries, and 1 hemolytic transfusion reaction). CONCLUSIONS: This is the first nationwide data regarding serious ATRs in Korea and could contribute to the implementation of an effective hemovigilance system.

Introduction of the Republic of Korea-the United States of America's Joint Exercise Against Biothreats in 2013: Able Response 13.

The Republic of Korea (ROK) and the the United States of America (USA) has held joint exercises to respond to biothreats in the Korean Peninsula since 2011. The exercise was called Able Response (AR) and it aims to coordinate interministerial procedures inside Korea and international procedures in requesting the medical resources urgently between ROK and USA, and among ROK and the United Nations, and nongovernmental organizations. AR13 was a functional exercise with a scenario that presumed a series of attack by terrorists, dispersing Bacillus anthracis in Seoul. The participants conducted exercises with action cells and using point-to-point communication system. It was followed by Senior Leadership Seminar participated by high-ranking officials in ROK and USA to discuss possible collaboration in advance. AR and its following actions will fortify collaboration between ROK and USA and enhance the capability of countermeasures against biothreats in Korea.

TRPV1 in GABAergic interneurons mediates neuropathic mechanical allodynia and disinhibition of the nociceptive circuitry in the spinal cord.

Neuropathic pain and allodynia may arise from sensitization of central circuits. We report a mechanism of disinhibition-based central sensitization resulting from long-term depression (LTD) of GABAergic interneurons as a consequence of TRPV1 activation in the spinal cord. Intrathecal administration of TRPV1 agonists led to mechanical allodynia that was not dependent on peripheral TRPV1 neurons. TRPV1 was functionally expressed in GABAergic spinal interneurons and activation of spinal TRPV1 resulted in LTD of excitatory inputs and a reduction of inhibitory signaling to spinothalamic tract (STT) projection neurons. Mechanical hypersensitivity after peripheral nerve injury was attenuated in TRPV1(-/-) mice but not in mice lacking TRPV1-expressing peripheral neurons. Mechanical pain was reversed by a spinally applied TRPV1 antagonist while avoiding the hyperthermic side effect of systemic treatment. Our results demonstrate that spinal TRPV1 plays a critical role as a synaptic regulator and suggest the utility of central nervous system-specific TRPV1 antagonists for treating neuropathic pain.