A Metabolomic Study of the Analgesic Effect of Lappaconitine Hydrobromide (LAH) on Inflammatory Pain

Metabolomic Study of the Analgesic Effect of Dalbergia hancei Benth (D. hancei) on Nociceptive Pain

Dalbergia hancei Benth (D. hancei) is a plant belonging to the Fabaceae family. It has analgesic and anti-inflammatory effects and is used by the Zhuang people to relieve pain. However, the mechanism underlying its analgesic effects remains unclear. This study investigates the analgesic effect of D. hancei based on metabolomics to explain the mechanism of its analgesia from a metabolomics perspective. The analgesic effect was evaluated through the acetic acid-induced writhing test and hot plate test. Three treatment groups received different dosages of D. hancei (0.91 g/kg, 3.64 g/kg, 7.28 g/kg). Its analgesic mechanism was investigated using analgesic behavioral tests and metabolomics. The results of analgesic behavioral experiments showed that all dose groups of D. hancei could relieve pain. A total of eight differential metabolites were identified in the metabolomics results. These biomarkers are associated with five metabolic pathways. Following treatment with D. hancei, eight differential metabolites were identified as regulated, primarily affecting amino acid metabolism, pantothenate and CoA biosynthesis, and steroid hormone biosynthesis. This study revealed the mechanism of analgesia from a metabolomic perspective to provide a basis for screening TCM drugs in pain treatment.

Protective effect of lappaconitine on Freund's complete adjuvant-induced arthritis exerted through P2X7 receptor-mediated regulation of M1/M2 balance in rats

OBJECTIVE

to investigate the anti-arthritic effects of lappaconitine (LA) on adjuvant-induced arthritis in Sprague-Dawley rats and its possible involvement in the regulation of M1/M2 macrophage balance through the P2X7 receptor (P2X7r).

METHODS

Rats were immunized with complete Freund's adjuvant and then intraperitoneally administered LA (2, 4, or 8 mg·kg-1·d-1) or methotrexate (0.5 mg/kg per 3 d) for 14 d. The anti-arthritic effects of LA were evaluated through arthritis index (AI) assessment, ankle diameter measurement, and histopathological staining analysis. The analgesic effect of LA on arthritis was measured using mechanical withdrawal threshold testing and gait scoring. The impacts of LA on macrophage polarization, the expression of pro-/anti-inflammatory cytokines and P2X7r were analyzed using quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting.

RESULTS

LA treatment significantly reduced AI scores, paw swelling, joint destruction, and inflammatory cell infiltration, and alleviated arthritis pain. Additionally, LA promoted a balanced M1/M2 ratio by increasing the mRNA expression level of M2 marker arginase 1 and decreasing those of M1 markers inducible nitric oxide synthase and interleukin (IL)-1β in synovial tissues. Furthermore, LA lowered the levels of three M1-related cytokines, namely tumor necrosis factor-α, IL-1β and IL-18, and raised the level of the M2-related cytokine IL-10. Further research showed that treatment with LA inhibited the expression of P2X7r.

CONCLUSION

Our findings indicate that the notable therapeutic and analgesic effects of LA on AIA rats are exerted through balancing the M1/M2 ratio, probably via P2X7r.

The Analgesic Effect of a Transdermal Lappaconitine Patch Combined With Ibuprofen Suspension for Children After Adenoidectomy and Tonsillectomy: A Randomized Clinical Trial

PURPOSE

To study the analgesic effects and side effects of a transdermal lappaconitine (TLA) patch, ibuprofen suspension (IS), and TLA combined with IS (TLACIS) after adenoidectomy and tonsillectomy.

DESIGN

Prospective, randomized clinical trial.

METHODS

The patients were randomized into three groups defined by different analgesic drug regimens: the TLA group, the IS group, and the TLACIS group. Pain scores at 2, 12, and 24 hours after surgery and adverse-event reports within the first postoperative week were collected.

RESULTS

Ultimately, this study included 102 cases in the TLA group, 101 cases in the IS group, and 101 cases in the TLACIS group. At 2 hours after surgery, the pain scores of the TLA and the TLACIS groups were both significantly lower than that of the IS group (all P < .05). At 12 and 24 hours after surgery, the pain score of the TLACIS group was significantly lower than those of the TLA and IS groups (all P < .05); furthermore, the pain score of the IS group was significantly lower than that of the TLA group (P < .05). Within 1 week after the operation, there was no significant difference in the incidence of adverse events.

CONCLUSIONS

The addition of a TLA patch can speed the onset of analgesia. In terms of analgesic effects, IS alone is more advantageous than TLA alone, while the combination of TLA and IS has the best analgesic effect. No significant differences were found in the incidence of adverse events among the three regimens.

In vitro and in vivo biological evaluation of Lappaconitine derivatives as potential anti-inflammatory agents

Natural products and their derivatives are a precious treasure in the pursuit of potent anti-inflammatory drugs. In this work, we measured the toxicity of 78 LA derivatives at 20 μM using MTT, then we evaluated the NO release of compounds without obvious toxicity in LPS-induced RAW.264.7 by Griess reagent, we identified three compounds, namely compounds 6, 19, 70, which exhibited promising anti-inflammatory potential. These compounds exhibited IC50 values of 10.34±2.05 μM, 18.18±4.80 μM and 15.66±0.88 μM. In addition, through ELISA kits, compounds 6, 19, 70 significantly reduce the production of inflammatory factors (TNF-α, IL-6, IL-1β). Real-time PCR and western blot analysis showed that compounds 6, 19, 70 inhibited the mRNA and protein expression of iNOS and COX-2. Notably, compound 6 exhibited the most potent inhibitory activity. In vitro, it inhibits LPS-induced phosphorylation of NF-κB p65, IκBα, ERK1/2, JNK, and p38 MAPKs in RAW264.7 cells. In vivo, compound 6 potently inhibits the secretion of inflammatory mediators and neutrophil activation in ALI mice. Our findings suggest that compound 6 may be a potential anti-inflammatory drug.

Traditional Chinese medicine alleviating neuropathic pain targeting purinergic receptor P2 in purinergic signaling: A review

Past studies have suggested that Chinese herbal may alleviate neuropathic pain, and the mechanism might target the inhibition of purinergic receptor P2. This review discusses whether traditional Chinese medicine target P2 receptors in neuropathic pain and its mechanism in order to provide references for future clinical drug development. The related literatures were searched from Pubmed, Embase, Sinomed, and CNKI databases before June 2023. The search terms included"neuropathic pain", "purinergic receptor P2", "P2", "traditional Chinese medicine", "Chinese herbal medicine", and "herb". We described the traditional Chinese medicine alleviating neuropathic pain via purinergic receptor P2 signaling pathway including P2X2/3 R, P2X3R, P2X4R, P2X7R, P2Y1R. Inhibition of activating glial cells, changing synaptic transmission, increasing painful postsynaptic potential, and activating inflammatory signaling pathways maybe the mechanism. Purine receptor P2 can mediate the occurrence of neuropathic pain. And many of traditional Chinese medicines can target P2 receptors to relieve neuropathic pain, which provides reasonable evidences for the future development of drugs. Also, the safety and efficacy and mechanism need more in-depth experimental research.

Synthesis, Pharmacological Evaluation, and Molecular Modeling of Lappaconitine-1,5-Benzodiazepine Hybrids

Diterpenoid alkaloids, originating from the amination of natural tetracyclic diterpenes, have long interested scientists due to their medicinal uses and infamous toxicity which has limited the clinical application of the native compound. Alkaloid lappaconitine extracted from various Aconitum and Delphinium species has displayed extensive bioactivities and active ongoing research to reduce its adverse effects. A convenient route to construct hybrid molecules containing diterpenoid alkaloid lappaconitine and 3H-1,5-benzodiazepine fragments was proposed. The key stage involved the formation of 5'-alkynone-lappaconitines in situ by acyl Sonogashira coupling of 5'-ethynyllappaconitine, followed by cyclocondensation with o-phenylenediamine. New hybrid compounds showed low toxicity and outstanding analgesic activity in experimental pain models, which depended on the nature of the substituent in the benzodiazepine nucleus. An analogous dependence was also shown for the antiarrhythmic activity in the epinephrine arrhythmia test in vivo. Studies on the isolated atrium have shown that the mechanism of action of the new compounds is included the blockade of beta-adrenergic receptors and potassium channels. Molecular docking analysis was conducted to determine the binding potential of target molecules with the voltage-gated sodium channel NaV1.5. All obtained results provide a basis for future rational modifications of lappaconitine, reducing side effects, while retaining its therapeutic effects.