Antinociceptive effect of gelsenicine, principal toxic alkaloids of gelsemium, on prostaglandin E2-induced hyperalgesia in mice: Comparison with gelsemine and koumine.

Gelsemium elegans (G.elegans) is a plant of the Loganiaceae family, known for its indole alkaloids, including gelsemine, koumine, and gelsenicine. Gelsemine and koumine are well-studied active alkaloids with low toxicity, valued for their anti-anxiety and analgesic properties. However, gelsenicine, another important alkaloid, remains underexplored due to its high toxicity. This study focuses on evaluating the analgesic properties of gelsenicine and comparing them with gelsemine and koumine. The results indicate that all three alkaloids exhibit robust analgesic properties, with gelsemine, koumine, and gelsenicine showing ED50 values of 0.82 mg/kg, 0.60 mg/kg, and 8.43 µg/kg, respectively, as assessed by the hot plate method. Notably, the therapeutic dose of gelsenicine was significantly lower than its toxic dose (LD50 = 0.185 mg/kg). The study also investigated the mechanism of action by analyzing the expression levels of GlyRα3 and Gephyrin. The PGE2 model group showed decreased expression levels of GlyRα3 and Gephyrin, while groups treated with gelsemine, koumine, and gelsenicine were able to reverse this decrease. These results suggest that gelsenicine effectively alleviates PGE2-induced hyperalgesia by upregulating the expression of GlyRα3 and Gephyrin, which are key targets of the Gly receptor pathway.

Network Pharmacology and Experimental Verification to Unveil the Mechanism of N-Methyl-D-Aspartic Acid Rescue Humantenirine-Induced Excitotoxicity.

Gelsemium is a medicinal plant that has been used to treat various diseases, but it is also well-known for its high toxicity. Complex alkaloids are considered the main poisonous components in Gelsemium. However, the toxic mechanism of Gelsemium remains ambiguous. In this work, network pharmacology and experimental verification were combined to systematically explore the specific mechanism of Gelsemium toxicity. The alkaloid compounds and candidate targets of Gelsemium, as well as related targets of excitotoxicity, were collected from public databases. The crucial targets were determined by constructing a protein-protein interaction (PPI) network. Subsequently, Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore the bioprocesses and signaling pathways involved in the excitotoxicity corresponding to alkaloids in Gelsemium. Then, the binding affinity between the main poisonous alkaloids and key targets was verified by molecular docking. Finally, animal experiments were conducted to further evaluate the potential mechanisms of Gelsemium toxicity. A total of 85 alkaloids in Gelsemium associated with 214 excitotoxicity-related targets were predicted by network pharmacology. Functional analysis showed that the toxicity of Gelsemium was mainly related to the protein phosphorylation reaction and plasma membrane function. There were also 164 pathways involved in the toxic mechanism, such as the calcium signaling pathway and MAPK signaling pathway. Molecular docking showed that alkaloids have high affinity with core targets, including MAPK3, SRC, MAPK1, NMDAR2B and NMDAR2A. In addition, the difference of binding affinity may be the basis of toxicity differences among different alkaloids. Humantenirine showed significant sex differences, and the LD50 values of female and male mice were 0.071 mg·kg-1 and 0.149 mg·kg-1, respectively. Furthermore, we found that N-methyl-D-aspartic acid (NMDA), a specific NMDA receptor agonist, could significantly increase the survival rate of acute humantenirine-poisoned mice. The results also show that humantenirine could upregulate the phosphorylation level of MAPK3/1 and decrease ATP content and mitochondrial membrane potential in hippocampal tissue, while NMDA could rescue humantenirine-induced excitotoxicity by restoring the function of mitochondria. This study revealed the toxic components and potential toxic mechanism of Gelsemium. These findings provide a theoretical basis for further study of the toxic mechanism of Gelsemium and potential therapeutic strategies for Gelsemium poisoning.

Suppressive Effects of Gelsemine on Anxiety-like Behaviors Induced by Chronic Unpredictable Mild Stress in Mice.

Gelsemine is an active principle and a major alkaloid found in Gelsemium genus of plants belonging to the Loganiaceae family. The aim of the present study was to explore whether gelsemine exerts anxiolytic effects on a mouse model of chronic-unpredictable-mild-stress (CUMS)-induced anxiety-like behaviors. NOD-like receptor protein 3 (NLRP3) inflammasome, downregulated cAMP-response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) were also evaluated as potential mechanisms. First, gelsemine reversed a CUMS-induced decrease in body-weight gain in mice. Next, gelsemine alleviated CUMS-induced anxiety-like behaviors, as evidenced by the increased distance traveled in the central zone of the open-field test, both the increased percentage of time spent and distance traveled in the light compartment, the increased number of transitions between compartments in the light/dark-transition test, and the increased percentage of entries and time spent in the open arm of the elevated plus-maze. In addition, gelsemine decreased the levels of pro-inflammatory cytokines, including interleukin (IL)-1ß and IL-6, in the hypothalamus and hippocampus of CUMS mice. Interestingly, further investigations revealed that gelsemine inhibited the CUMS-induced activation of NLRP3-inflammasome pathways and downregulated CREB and BDNF overexpression in the hypothalamus. In summary, gelsemine alleviated anxiety-like behaviors in the CUMS-induced mouse model. Gelsemine exerted its anxiolytic effects by modulating the NLRP3 and CREB/BDNF pathways.

A Proteomics Study of the Subacute Toxicity of Rat Brain after Long- Term Exposure of Gelsemium elegans.

BACKGROUND: Gelsemium elegans (G. elegans) has been shown to have strong pharmacological and pharmacodynamic effects in relevant studies both in China and USA. G. elegans has been used as a traditional medicine to treat a variety of diseases and even has the potential to be an alternative to laboratory synthesized drugs. However, its toxicity severely limited its application and development. At present, there is little attention paid to protein changes in toxicity. AIM: This study investigated the toxicity effects after long-term exposure of G. elegans of the rat brain through proteomic. METHODS: 11 differential abundance proteins were detected, among which 8 proteins were higher in the G. elegans- exposure group than in the control group, including Ig-like domain-containing protein (N/A), receptor-type tyrosine-protein phosphatase C (Ptprc), disheveled segment polarity protein 3 (Dvl3), trafficking protein particle complex 12 (Trappc12), seizure-related 6 homologlike (Sez6l), transmembrane 9 superfamily member 4 (Tm9sf4), DENN domain-containing protein 5A (Dennd5a) and Tle4, whereas the other 3 proteins do the opposite including Golgi to ER traffic protein 4 (Get4), vacuolar protein sorting 4 homolog B (Vps4b) and cadherin-related 23 (CDH23). Furthermore, we performed validation of WB analysis on the key protein CDH23. RESULTS: Finally, only fewer proteins and related metabolic pathways were affected, indicating that there was no accumulative toxicity of G. elegans. G. elegans has the potential to develop and utilize of its pharmacological activity. CHD23, however, is a protein associated with hearing. CONCLUSION: Whether the hearing impairment is a sequela after G. elegans exposure remains to be further studied.

Sex Differences in the In Vivo Exposure Process of Multiple Components of Gelsemium elegans in Rats.

Asian Gelsemium elegans (G. elegans) has a wide range of pharmacological activities. However, its strong toxicity limits its potential development and application. Interestingly, there are significant gender differences in G. elegans toxicity in rats. This work aimed to elucidate the overall absorption, distribution, metabolism, and excretion (ADME) of whole G. elegans crude extract in female and male rats using high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC/QqTOF-MS), which facilitates determining the reasons for the gender differences in toxicity. A total of 25 absorbed bioactive components and 3 related produced metabolites were tentatively identified in female rats, while only 17 absorbed bioactive components and 3 related produced metabolites were identified in male rats. By comparison of peak intensities, most compounds were found to be more active in absorption, distribution and excretion in female rats than in male rats, which showed that female rats were more sensitive to G. elegans. This study was the first to investigate the multicomponent in vivo process of G. elegans in rats and compare the differences between sexes. It was hypothesized that differences in the absorption of gelsedine-type alkaloids were one of the main reasons for the sex differences in G. elegans toxicity.

Simultaneous determination of five amino acid neurotransmitters in rat and porcine blood and brain by two-dimensional liquid chromatography.

A method for the simultaneous determination of aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA) in animal blood and brain by two-dimensional liquid chromatography (2D-LC) combined with ultraviolet detection was established for the first time. First, the amino acid neurotransmitters (AANTs) were labeled on the corresponding fluorescent derivatives with 4-fluoro-7-nitrobenzofurazan (NBD-F), enriched on the extraction column and automatically transferred to the analytical column to achieve on-line extraction and complete separation of the target components. This method exhibited good selectivity, and the correlation coefficients for the analyte calibration curves of were > 0.99. The intra- and inter-day precisions were ≤ 16.03, and the accuracies were in the range of 70.59-116.20%. The system realizes the rapid detection and stability quantification of the five AANTs, which proves that the alternative dilution method is feasible. The results show that the system has high loading capacity, excellent resolution, and good peak shape and is not affected by other endogenous substances. Moreover, the developed method has been successfully applied to the analysis of biological samples in the blood and whole brain of rats and pigs. The content of AANTs in the hippocampus and cortex of rats was higher than that in those of pigs. This method is expected to provide applicability for the determination of AANTs in pharmacological, pharmaceutical and clinical research in nervous science.