Effect of neurotropin on the binding of high molecular weight kininogen and Hageman factor to human umbilical vein endothelial cells and the autoactivation of bound Hageman factor

Intramuscularly injected neurotropin reduced muscular mechanical hyperalgesia induced by repeated cold stress in rats

An extract of rabbit skin inflamed by inoculation with the vaccinia virus, neurotropin [by intravenous, oral, and intramuscular (i.m.) administration], has been used in China and Japan for the treatment of chronic pain. In this study, we investigated the analgesic mechanism of i.m. neurotropin. Rats were exposed to repeated cold stress, and muscular mechanical hyperalgesia was evaluated by measuring the withdrawal threshold of the gastrocnemius muscle using Randall-Selitto apparatus. I.m. but not subcutaneous, neurotropin dose dependently reduced the repeated cold stress-induced muscular mechanical hyperalgesia for 3 h, but it had no effect in normal rats. Injections of neurotropin into the right gastrocnemius, quadriceps femoris, biceps brachii, and trapezius muscles reduced the muscular mechanical hyperalgesia of the gastrocnemius muscle bilaterally. Intrathecal administration of antagonists to GABAergic, serotonergic, and cholinergic receptors, but not α2-adrenergic receptors, and intraperitoneal administration of opioid receptor antagonist inhibited the analgesic effect of neurotropin. These results indicated that an i.m. injection of neurotropin induced long-lasting wide-spread bilateral muscular analgesia by activating spinal serotonergic and GABAergic receptors. As distinct from analgesia by systemic administration, spinal cholinergic and opioidergic, but not adrenergic receptors, are also involved. The present study supports the effectiveness of neurotropin treatment for muscular mechanical hyperalgesia.

Neuroprotective effects of an extract from the inflamed skin of rabbits inoculated with vaccinia virus on glutamate-induced neurotoxicity in cultured neuronal cell line

Objective: Protein-free extracts from the inflamed skin of rabbits inoculated with vaccinia virus (Rosemorgen^® and Neurotropin^®) are widely employed to combat chronic pain and treat allergic conditions in human subjects in Japan. However, the pharmacologic mechanisms of Rosemorgen^® and Neurotropin^® remain unclear.

Methods: In this study, we examined the effects of Rosemorgen^® on L-glutamic acid (Glu)-induced cell death in N18-RE-105 neural cell line, which only possessed non-N-methyl-D-aspartate (NMDA)-type receptors.

Results: There were many large cytoplasmic cells and elongation of fivers in phosphate-buffered saline (PBS) additional group without Glu. In PBS and Glu simultaneous additional group, the survival ratio was decrease significantly compared with PBS alone group. Moreover, there were dead cells which did not have cytoplasm and aggregated nucleus. The Glu-induced cell death of N18-RE-105 cells was inhibited by both pre-treatment (24 hours before Glu treatment) and simultaneous treatment with Rosemorgen^®. There were many large cytoplasmic cells and elongation of fivers in Rosemorgen^® group.

Discussion: From this finding in N18-RE-105 cells, Rosemorgen^® was concluded to inhibit Glu-induced cell death via non-NMDA type receptors. One of the pharmacologic mechanisms of Rosemorgen^® has been clear. These results suggest that Rosemorgen^® depresses allodynia and chronic pain through interaction with non-NMDA type receptors.

Protective effect of neurotropin against lipopolysaccharide-induced hypotension and lethality linked to suppression of inducible nitric oxide synthase induction

Neurotropin is a non-protein extract from the dermis of rabbits inoculated with vaccinia virus and has been clinically used as an analgesic in Japan. We present in the current report evidence for its potential therapeutic value against endotoxin shock. Administration of this compound prior to lipopolysaccharide (LPS) challenge resulted in a reversal of a decrease of the mean arterial pressure in rats and also amelioration of lethality in mice. Anti-inducible nitric oxide synthase (iNOS) Western blotting of tissue extracts from LPS-treated mice revealed almost complete suppression of iNOS induction by Neurotropin. The findings in vivo were reproduced in in vitro experiments in which cultured human umbilical vascular endothelial cells were challenged with LPS. Simultaneous treatment of the cells with Neurotropin resulted in complete suppression of iNOS induction and significant reduction of cell death. These results suggested a therapeutic value of Neurotropin in the treatment of endotoxin shock that was linked, at least in part, to suppression of iNOS induction and reduced cell damage in vascular endothelial cells.