Bullatine A

Brain Res Bull. 2013 Aug;97:81-5.

Bullatine A, a diterpenoid alkaloid of the genus Aconitum, could attenuate ATP-induced BV-2 microglia death/apoptosis via P2X receptor pathways.[Pubmed: 23769848 ]

Bullatine A (BLA), a diterpenoid alkaloid of the genus Aconitum, possesses anti-rheumatic, anti-inflammatory and anti-nociceptive effects. The mechanism underlying the effects was examined in the present study.
METHODS AND RESULTS:
The effect of BLA on extracellular ATP induced cell death/apoptosis and pro-inflammatory cytokines release were investigated using BV-2 microglia cell line. The mediation/efficacy of inflammatory cytokines and P2X receptors was evaluated by detecting the mRNA levels of iNOS, IL-6, IL-1β and P2X receptors, respectively. The results demonstrated that BV-2 cells could be damaged after incubation with higher dose of ATP, leading to activation of pro-inflammatory cytokines, transcriptional activation of iNOS and overproduction of NO via activation of P2X receptor. The BLA (1-50μM) potently inhibits ATP-induced BV-2 cell death/apoptosis and P2X receptor-mediated inflammatory responses via selectively suppressing the up-regulation of P2X7 receptor mRNA.
CONCLUSIONS:
Since P2X7 receptors have an important role in immune and pain response, inflammation and inflammatory disease, this discovery of BLA as a potent P2X7 antagonist indicated that BLA may be a potential useful candidate for the treatment of neurodegenerative diseases such as arthritis.

Zhongguo Zhong Yao Za Zhi. 2008 Mar;33(5):513-6.

Effects of volatile oil of Rhizoma zingiberis and other two kinds of volatile oil on percutaneous penetration of bullatine A via hairless mouse skin in vitro[Pubmed: 18536371]

To investigate the effects of volatile oils of Rhizoma Acori Tatarinowii (RAT), Semen Myristicae (SM) and Pericarpium Citri Reticulatae (PCR) on percutaneous penetration of Bullatine A via hairless mouse skin in vitro.
METHODS AND RESULTS:
By an improved Franz diffusion, the effects of three kinds of volatile oils on the percutaneous penetration of Bullatine A were observed and compared with Azone, and the cumulative amount of Bullatine A was determined by HPLC. The penetration enhancement ratios of Bullatine A with 7% volatile oil RAT and SM, 5% volatile oil of PCR and 3% Azone were 6.52, 6.74, 2.18, 6.03, respectively.
CONCLUSIONS:
The volatile oil of RAT, SM and PCR enhance permeation of Bullatine A, effectively.

J Neuroinflammation. 2016 Aug 30;13(1):214.

Bullatine A stimulates spinal microglial dynorphin A expression to produce anti-hypersensitivity in a variety of rat pain models.[Pubmed: 27577933]

Aconiti brachypodi Radix (Xue-shang-yi-zhi-hao) has been prescribed to manage chronic pain, arthritis, and traumatic injuries. Bullatine A, a C20-diterpenoid alkaloid, is one of its principle effective compounds. This study aimed to investigate the anti-hypersensitivity of Bullatine A in a variety of rat pain models and explore its mechanisms of action.
METHODS AND RESULTS:
Rat neuropathic pain, inflammatory pain, diabetic neuropathic pain, and bone cancer pain models were used. Dynorphin A and pro-inflammatory cytokines were measured in the spinal cord and cultured primary microglia. Double immunofluorescence staining of dynorphin A and glial and neuronal cellular markers was also measured in the spinal cord. Subcutaneous and intrathecal injection of Bullatine A dose-dependently attenuated spinal nerve ligation-, complete Freud's adjuvant-, diabetes-, and bone cancer-induced mechanical allodynia and thermal hyperalgesia, with the efficacies of 45-70 % inhibition, and half-effective doses of 0.9-1.9 mg/kg for subcutaneous injection. However, Bullatine A was not effective in blocking acute nociceptive response in the normal condition. Bullatine A specifically stimulated dynorphin A expression in microglia in the spinal cord in vivo and cultured primary microglia in vitro; the stimulatory effects were completely inhibited by the microglial inhibitor minocycline. In contrast, Bullatine A did not have an inhibitory effect on peripheral nerve injury- or lipopolysaccharide-induced pro-inflammatory cytokine expression. The spinal anti-allodynic effects of Bullatine A were entirely blocked by intrathecal injection of minocycline, the specific dynorphin A antiserum, and the selective k-opioid receptor antagonist.
CONCLUSIONS:
We, for the first time, demonstrate that Bullatine A specifically attenuates pain hypersensitivity, regardless of the pain models employed. The results also suggest that stimulation of spinal microglial dynorphin A expression mediates Bullatine A anti-nociception in pain hypersensitivity conditions.

J Ethnopharmacol. 2017 Jan 20;196:151-159.

Concurrent bullatine A enhances morphine antinociception and inhibits morphine antinociceptive tolerance by indirect activation of spinal κ-opioid receptors.[Pubmed: 27989510 ]

Bullatine A, a C20-diterpenoid alkaloid and one of the major effective ingredients in Aconiti brachypodi Radix (Xue-shang-yi-zhi-hao), can block pain hypersensitivity in a variety of rodent models through expression of spinal microglial dynorphin A. To assess the interaction between Bullatine A and morphine on antinociception in acute nociception and pain hypersensitivity states, with the exogenous synthetic dynorphin A as a comparison
METHODS AND RESULTS:
Spinal nerve ligation-induced neuropathic rats and naïve mice were used for assessing the acute and chronic interactions of Bullatine A/dynorphin A with morphine. Single subcutaneous injection of Bullatine A or dynorphin A(1-17) did not either alter formalin- and thermally (hot-plate and water immersion tests)-induced acute nociception or potentiate morphine antinociception in naïve mice. In contrast, Bullatine A dose-dependently inhibited formalin-induced tonic pain with the efficacy of 54% inhibition and the half-effective dose of 0.9mg/kg. Concurrent Bullatine A additively enhanced morphine antinociception. In neuropathic rats, the antinociceptive effects of multiple bidaily intrathecal injections of Bullatine A and dynorphin A remained consistent over 13 days, whereas morphine produced progressive and complete tolerance to antinociception, which was completely inhibited by concurrent Bullatine A and dynorphin A. A single intrathecal injection of Bullatine A and dynorphin A immediately reversed established morphine tolerance in neuropathic rats, although the blockade was a less degree in the thermally induced mouse acute nociceptive tests. The inhibitory effects of Bullatine A and dynorphin A on morphine tolerance were immediately and completely attenuated by intrathecal dynorphin A antibody and/or selective κ-opioid receptor antagonist GNTI.
CONCLUSIONS:
These results suggest that Bullatine A produces antinociception without induction of tolerance and inhibits morphine antinociceptive tolerance, and provide pharmacological basis for concurrent Bullatine A and morphine treatment for chronic pain and morphine analgesic tolerance.