strychnine and Bone-Neoplasms

To examine the effects of brucine on the invasion, migration and bone resorption of receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis.. The osteoclastogenesis model was builded by co-culturing human breast tumor MDA-MB-231 and mouse RAW264.7 macrophages cells. RANKL (50 ng/mL) and macrophage-colony stimulating factor (50 ng/mL) were added to this system, followed by treatment with brucine (0.02, 0.04 and 0.08 mmol/L), or 10 μmol/L zoledronic acid as positive control. The migration and bone resorption were measured by transwell assay and in vitro bone resorption assay. The protein expressions of Jagged1 and Notch1 were investigated by Western blot. The expressions of transforming growth factor-β1 (TGF-β1), nuclear factor-kappa B (NF-κB) and Hes1 were determined by enzyme-linked immunosorbent assay.. Compared with the model group, brucine led to a dose-dependent decrease on migration of MDA-MB-231 cells, inhibited RANKL-induced osteoclastogenesis and bone resorption of RAW264.7 cells (P<0.01). Furthermore, brucine decreased the protein levels of Jagged1 and Notch1 in MDA-MB-231 cells and RAW264.7 cells co-cultured system as well as the expressions of TGF-β1, NF-κB and Hes1 (P<0.05 or P<0.01).. Brucine may inhibit osteoclastogenesis by suppressing Jagged1/Notch1 signaling pathways.

Topics: Animals; Bone Neoplasms; Breast Neoplasms; Cell Differentiation; Cells, Cultured; Female; Humans; Jagged-1 Protein; Macrophages; Mice; Osteoclasts; Receptor, Notch1; Signal Transduction; Strychnine

The present study examined the antinociceptive effects of gelsemine, the principal alkaloid in Gelsemium sempervirens Ait. A single intrathecal injection of gelsemine produced potent and specific antinociception in formalin-induced tonic pain, bone cancer-induced mechanical allodynia, and spinal nerve ligation-induced painful neuropathy. The antinociception was dose-dependent, with maximal inhibition of 50% to 60% and ED50 values of 0.5 to 0.6 μg. Multiple daily intrathecal injections of gelsemine for 7 days induced no tolerance to antinociception in the rat model of bone cancer pain. Spinal gelsemine was not effective in altering contralateral paw withdrawal thresholds, and had only a slight inhibitory effect on formalin-induced acute nociception. The specific antinociception of gelsemine in chronic pain was blocked dose-dependently by the glycine receptor (GlyR) antagonist strychnine with an apparent ID50 value of 3.8 μg. Gelsemine concentration-dependently displaced H(3)-strychnine binding to the membrane fraction of rat spinal cord homogenates, with a 100% displacement and a Ki of 21.9μM. Gene ablation of the GlyR α3 subunit (α3 GlyR) but not α1 GlyR, by a 7-day intrathecal injection of small interfering RNA (siRNA) targeting α3 GlyR or α1 GlyR, nearly completely prevented gelsemine-induced antinociception in neuropathic pain. Our results demonstrate that gelsemine produces potent and specific antinociception in chronic pain states without induction of apparent tolerance. The results also suggest that gelsemine produces antinociception by activation of spinal α3 glycine receptors, and support the notion that spinal α3 glycine receptors are a potential therapeutic target molecule for the management of chronic pain.

Topics: Alkaloids; Analgesics; Animals; Binding, Competitive; Bone Neoplasms; Chronic Pain; Gelsemium; Glycine Agents; Injections, Intraventricular; Injections, Spinal; Ligation; Male; Neuralgia; Pain Measurement; Postural Balance; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Receptors, Glycine; RNA, Small Interfering; Spinal Cord; Spinal Nerves; Strychnine

To study the effects of brucine on vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) in a nude mouse model of bone metastasis due to breast cancer, and to assess the possible antitumor mechanism of brucine.. A syringe needle was used to directly inject 0.2 mL monoplast suspension (with 2×10(5) human breast cancer cells contained) into the bony femoral cortex of the right hind leg for modeling. Twenty-five nude mice were randomized into five groups and administered with an intraperitoneal injection of saline or drug for 8 consecutive days: model group (0.2 mL normal saline), low-dose brucine group (1.73 mg·kg(-1)), medium-dose brucine group (3.45 mg·kg(-1)), high-dose brucine group (6.90 mg·kg(-1)), and thalidomide group (200 mg·kg(-1)). Diet and activity were recorded, and the tumors were harvested 5 weeks later. The percentage of VEGF-positive cells was determined with hematoxylin and eosin staining and immunohistochemical staining, and MVD expression was determined by optical microscopy.. The VEGF expressions in brucine- or thalidomide-treated mice were significantly reduced as compared with mice in the model group (P <0.01). There were no significant difference between the high-dose brucine group and the thalidomide group (P >0.05). Significant difference was between the high- and low-dose brucine group P<0.05). Further, VEGF expression was significantly increased in the low- and medium-dose brucine groups compared with the thalidomide group (P <0.05). The MVD values in the three brucine and thalidomide groups were significantly lower than that in the model group (P <0.01). The MVD values in the medium- and high-dose brucine groups were not significantly different from those in the thalidomide group (P >0.05), while the MVD value showed a significant increase in the low-dose group compared with the thalidomide group (P <0.05).. Brucine could inhibit the growth of breast cancer to bone metastases, possibly by inhibiting tumor angiogenesis.

Topics: Animals; Bone Neoplasms; Breast Neoplasms; Cell Line, Tumor; Disease Models, Animal; Female; Humans; Immunohistochemistry; Mice; Mice, Inbred BALB C; Mice, Nude; Microvessels; Strychnine; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays