The analgesic effect and possible mechanisms by which koumine alters type II collagen-induced arthritis in rats

Effect of cytochrome P450 3A4 on tissue distribution of humantenmine, koumine, and gelsemine, three alkaloids from the toxic plant Gelsemium

Humantenmine, koumine, and gelsemine are three indole alkaloids found in the highly toxic plant Gelsemium. Humantenmine was the most toxic, followed by gelsemine and koumine. The aim of this study was to investigate and analyze the effects of these three substances on tissue distribution and toxicity in mice pretreated with the Cytochrome P450 3A4 (CYP3A4) inducer ketoconazole and the inhibitor rifampicin. The in vivo test results showed that the three alkaloids were absorbed rapidly and had the ability to penetrate the blood-brain barrier. At 5 min after intraperitoneal injection, the three alkaloids were widely distributed in various tissues and organs, the spleen and pancreas were the most distributed, and the content of all tissues decreased significantly at 20 min. Induction or inhibition of CYP3A4 in vivo can regulate the distribution and elimination effects of the three alkaloids in various tissues and organs. Additionally, induction of CYP3A4 can reduce the toxicity of humantenmine, and vice versa. Changes in CYP3A4 levels may account for the difference in toxicity of humantenmine. These findings provide a reliable and detailed dataset for drug interactions, tissue distribution, and toxicity studies of Gelsemium alkaloids.

Effect of dietary koumine on the immune and antioxidant status of carp (Cyprinus carpio) after Aeromonas hydrophila infection

Koumine (KM) has anxiolytic, anti-inflammatory and growth-promoting effects in pigs and sheep. Based on the growth-promoting and immunological effects of koumine, the present study was conducted on Cyprinus carpio (C. carpio) with four KM concentrations: 0 mg/kg, 0.2 mg/kg, 2 mg/kg, and 20 mg/kg for 10 weeks, followed by a 1-week Aeromonas hydrophila (A. hydrophila) infection experiment. The effect of KM on the immunity of A. hydrophila infected carp was analyzed by histopathology, biochemical assay, and qRT-PCR to assess the feasibility of KM in aquaculture. The results showed that the presence of KM alleviated pathogen damage to carp tissues. At 2 mg/kg and 20 mg/kg concentrations of KM successively and significantly elevated (p < 0.05) the SOD activities in the intestinal tract, hepatopancreas and kidney of carp. The expression levels of hepatopancreatic antioxidant genes Nrf2 and IGF-1 were significantly up-regulated in the same group (p < 0.05), while the expression levels of immune genes IL-8 and IL-10 were down-regulated. In summary, KM at concentrations of 2 mg/kg and 20 mg/kg could regulate the expression of antioxidant and immune genes in various tissues in an orderly and rapid manner, and significantly improve the antioxidant and immune abilities of carp, which is conducive to the improvement of the resilience of carp.

New Monoterpenoid Indole Hybrids from Gelsemium elegans with Anti-Inflammatory and Osteoclast Inhibitory Activities

Gelsegansymines A (1) and B (2), two new indole alkaloids along with six known analogues (3-8) were isolated from the aerial parts of Gelsemium elegans. Their structures were elucidated by means of spectroscopic techniques. Structurally, compounds 1 and 2 possessed the rare cage-like gelsedine skeleton hybrid with bicyclic monoterpenoid. The anti-inflammatory activities of isolated compounds (1-3) were tested on LPS induced RAW264.7 cells. Under the treated concentration without toxicity for cells, the cytokines levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were evaluated by Griess method and enzyme-linked immunosorbent assay (ELISA). The results showed that compounds 1-3 exhibited anti-inflammatory activities with dose-dependent manner range from 12.5 to 50 μmol/L. Furthermore, the inhibitory activities of compounds 1 and 2 on receptor activator of NF-κB ligand (RANKL) induced osteoclast formation were tested in vitro. Compounds 1 and 2 at 5 μmol/L exhibited the significant inhibitory effect on the osteoclastogenesis induced by RANKL. This work reported the anti-inflammatory and osteoclast inhibitory activities of new monoterpenoid indole hybrids, which may inspire the further light on the related traditional application research of G. elegans.

Recent progress in chemistry and bioactivity of monoterpenoid indole alkaloids from the genus gelsemium: a comprehensive review

Monoterpenoid indole alkaloids (MIAs) represent a major class of active ingredients from the plants of the genus Gelsemium. Gelsemium MIAs with diverse chemical structures can be divided into six categories: gelsedine-, gelsemine-, humantenine-, koumine-, sarpagine- and yohimbane-type. Additionally, gelsemium MIAs exert a wide range of bioactivities, including anti-tumour, immunosuppression, anti-anxiety, analgesia, and so on. Owing to their fascinating structures and potent pharmaceutical properties, these gelsemium MIAs arouse significant organic chemists' interest to design state-of-the-art synthetic strategies for their total synthesis. In this review, we comprehensively summarised recently reported novel gelsemium MIAs, potential pharmacological activities of some active molecules, and total synthetic strategies covering the period from 2013 to 2022. It is expected that this study may open the window to timely illuminate and guide further study and development of gelsemium MIAs and their derivatives in clinical practice.

Toxic Effects of Koumine on the Early-Life Development Stage of Zebrafish

Koumine is one of the most abundant alkaloids found in Gelsemium elegans, and it has a wide range of pharmacological effects including antitumor, anti-inflammatory, analgesic treatment effects, and antianxiety. However, its high toxicity and unclear mechanism of action have greatly limited the medicinal development and use of koumine. We investigated the toxic effects of koumine on the developmental toxicity and behavioral neurotoxicity of zebrafish embryos and larvae. Embryos at 6 h postfertilization (hpf) were exposed to 12.5, 25, 50, 75, and 100 mg/L of koumine until 120 hpf. Koumine affected the hatching and heartbeats of the embryos. The morphological analysis also revealed many abnormalities, such as shortened bodies, yolk sac edemas, tail malformations, and pericardial edemas. To identify the neurotoxicity of koumine, the behavior of the larvae was measured. Koumine at 50 and 100 mg/L affect the escape response. The embryos exhibited uncoordinated muscle contractions along the body axis in response to touch at 36 hpf. More importantly, we found that the neurotoxicity of koumine is mainly caused by influencing the ACh content and the activity of AChE without impairing motor neuron development. A comprehensive analysis shows that a high concentration of koumine has obvious toxic effects on zebrafish, and the safe concentration of koumine for zebrafish should be less than 25 mg/L. These results will be valuable for better understanding the toxicity of koumine and provide new insights into the application of koumine.

Koumine alleviates rheumatoid arthritis by regulating macrophage polarization

ETHNOPHARMACOLOGICAL RELEVANCE

The imbalance between M1-and M2-polarized macrophages is one of the major pathophysiological changes in RA. Therefore, targeted macrophage polarization may be an effective therapy for RA. Koumine, an alkaloid monomer with the highest content and low toxicity in Gelsemium elegans Benth., has the effect of treating RA by playing an immunomodulatory role by influencing various immune cells. However, whether koumine affects macrophage polarization in RA and the associated molecular mechanisms remain unknown.

AIM OF THE STUDY

To investigate the mechanism of the anti-RA effect of koumine on macrophage polarization.

MATERIALS AND METHODS

The effect of koumine on macrophage polarization was investigated in vivo and in vitro. We first explored the effects of koumine on AIA rats and detected the levels of M1/M2 macrophage polarization markers in the spleen by western blotting. Then, we explored the regulatory effect of koumine on M1/M2 macrophage polarization and the effect on the PI3K/AKT signaling pathway in vitro. Finally, we verified the effects of koumine on macrophage polarization in CIA mice.

RESULTS

We found that koumine alleviated symptoms, including relieving pain, reducing joint redness and swelling in AIA rats and restoring the M1/M2 macrophage balance in vivo. Interestingly, koumine had an inhibitory effect on both M1 and M2 macrophage polarization in vitro, but it had a stronger inhibitory effect on M1 macrophage. In a mixed polarization experiment, koumine mainly inhibited M1 macrophage polarization and had an inhibitory effect on the PI3K/AKT signaling pathway. Finally, we found that koumine had therapeutic effects on CIA mice, regulated macrophage polarization and inhibited the PI3K/AKT signaling pathway.

CONCLUSIONS

Our results reveal that koumine regulates macrophage polarization through the PI3K/AKT signaling pathway. This may be one of the important mechanisms of its anti-RA effect, which provides a theoretical and scientific basis for the possible clinical application of koumine.

Koumine regulates macrophage M1/M2 polarization via TSPO, alleviating sepsis-associated liver injury in mice

BACKGROUND

Translocator protein (TSPO) is an 18-kDa transmembrane protein found primarily in the mitochondrial outer membrane, and it is implicated in inflammatory responses, such as cytokine release. Koumine (KM) is an indole alkaloid extracted from Gelsemium elegans Benth. It has been reported to be a high-affinity ligand of TSPO and to exert anti-inflammatory and immunomodulatory effects in our recent studies. However, the protective effect of KM on sepsis-associated liver injury (SALI) and its mechanisms are unknown.

PURPOSE

To explore the role of TSPO in SALI and then further explore the protective effect and mechanism of KM on SALI.

METHODS

The effect of KM on the survival rate of septic mice was confirmed in mouse models of caecal ligation and puncture (CLP)-induced and lipopolysaccharide (LPS)-induced sepsis. The protective effect of KM on CLP-induced SALI was comprehensively evaluated by observing the morphology of the mouse liver and measuring liver injury markers. The serum cytokine content was detected in mice by flow cytometry. Macrophage polarization in the liver was examined using western blotting. TSPO knockout mice were used to explore the role of TSPO in sepsis liver injury and verify the protective effect of KM on sepsis liver injury through TSPO.

RESULTS

KM significantly improved the survival rate of both LPS- and CLP-induced sepsis in mice. KM has a significant liver protective effect on CLP-induced sepsis in mice. KM treatment ameliorated liver ischaemia, improved liver pathological injuries, and decreased the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and proinflammatory cytokines in serum. Western blotting results showed that KM inhibited M1 polarization of macrophages and promoted M2 polarization. In TSPO knockout mice, we found that TSPO knockout can improve the survival rate of septic mice, ameliorate liver ischaemia, improve liver pathological injuries, and decrease the levels of ALT, AST, and LDH. In addition, TSPO knockout inhibits the M1 polarization of macrophages in the liver of septic mice and promotes M2 polarization and the serum levels of proinflammatory cytokines. Interestingly, in TSPO knockout septic mice, these protective effects of KM were no longer effective.

CONCLUSIONS

We report for the first time that TSPO plays a critical role in sepsis-associated liver injury by regulating the polarization of liver macrophages and reducing the inflammatory response. KM, a TSPO ligand, is a potentially desirable candidate for the treatment of SALI that may regulate macrophage M1/M2 polarization through TSPO in the liver.

A Novel Progress: Glial Cells and Inflammatory Pain

Inflammatory pain is the perception of noxious stimuli that occurs during inflammation or an immune response. Glial cells are widespread in the central and peripheral nervous systems, supporting and guiding the migration of neurons, participating in the immune response, forming the myelin sheath and blood-brain barrier, and maintaining the concentration of potassium ions outside nerve cells. Recent studies have shown that glial cells have a significant connection with the production and development of inflammatory pain. This article reviews the relationship, mechanisms, therapeutic targets between five types of glial cells and inflammatory pain, and the medicine composition that can effectively inhibit inflammatory pain. It expands the study on the mechanism of glial cells regulating pain and provides new ideas for the therapy of inflammatory pain.

The immunomodulatory effect of koumine on B cells under dependent and independent responses by T cells

Dysregulated activation of polyclonal B cells and production of pathogenic antibodies are involved in the development of rheumatoid arthritis (RA). Therefore, targeted B cell therapy is effective against RA. Gelsemium elegans (Gardn. & Champ.) Benth., a toxic plant widely distributed in Southeast Asia, has been used for treating rheumatoid pain, neuropathic pain, spasticity, skin ulcers, and cancers for many years in traditional Chinese medicine. Koumine, an alkaloid monomer from Gelsemium elegans Benth., exerts therapeutic effects against RA. However, whether koumine affects B cells remains unknown. In this study, the effect of koumine on B cells under T cell-independent (TI) and T cell-dependent (TD) immune responses is investigated in vitro and in vivo. Mouse primary B cells were obtained by immunomagnetic bead sorting, and immunomodulatory effects of koumine on the activation, proliferation, and differentiation of B cells were determined in TI and TD models induced by lipopolysaccharide (LPS) and anti-CD40 antibodies in vitro, respectively. The humoral immune responses of TI and TD were established using NP-AECM-FICOLL and NP-CGG in C57BL/6J mice, respectively. We found that koumine inhibited B cell differentiation in the TI model and inhibited B cell activation and proliferation in the TD model in vitro. Koumine also inhibited antibody secretion in TI immune response, TD initial immune response, and in TD secondary immune response. Our results reveal that koumine has a direct and indirect immune regulatory effect on B cells, showing that it can directly inhibit the differentiation and secretion of autoantibodies after abnormal activation of B cells, and indirectly inhibit the activation and proliferation of TD B cells to reduce the secretion of antibodies. It may be an important mechanism for its anti-RA effect in mice, providing a rationale and laboratory data support for the application of koumine in anti-human RA therapy.

Koumine modulates spinal microglial M1 polarization and the inflammatory response through the Notch-RBP-Jκ signaling pathway, ameliorating diabetic neuropathic pain in rats

BACKGROUND

Diabetic neuropathic pain (DNP), a complication of diabetes, has serious impacts on human health. As the pathogenesis of DNP is very complex, clinical treatments for DNP is limited. Koumine (KM) is an active ingredient extracted from Gelsemium elegans Benth. that exerts an inhibitory effect on neuropathic pain (NP) in several animal models.

PURPOSE

To clarify the anti-NP effect of KM on rats with DNP and the molecular mechanisms involving the Notch- Jκ recombination signal binding protein (RBP-Jκ) signaling pathway.

METHODS

Male Sprague-Dawley rats were administered streptozocin (STZ) by intraperitoneal injection to induce DNP. The effect of KM on mechanical hyperalgesia in rats with DNP was evaluated using the Von Frey test. Microglial polarization in the spinal cord was examined using western blotting and quantitative real-time PCR. The Notch-RBP-Jκ signaling pathway was analysed using western blotting.

RESULTS

KM attenuated DNP during the observation period. In addition, KM alleviated M1 microglial polarization in STZ-induced rats. Subsequent experiments revealed that Notch-RBP-Jκ signaling pathway was activated in the spinal cord of rats with DNP, and the activation of this pathways was decreased by KM. Additionally, KM-mediated analgesia and deactivation of the Notch-RBP-Jκ signaling pathway were inhibited by the Notch signaling agonist jagged 1, indicating that the anti-DNP effect of KM may be regulated by the Notch-RBP-Jκ signaling pathway.

CONCLUSIONS

KM is a potentially desirable candidate treatment for DNP that may inhibit microglial M1 polarization through the Notch-RBP-Jκ signaling pathway.

Identification of Koumine as a Translocator Protein 18 kDa Positive Allosteric Modulator for the Treatment of Inflammatory and Neuropathic Pain

Koumine is an alkaloid that displays notable activity against inflammatory and neuropathic pain, but its therapeutic target and molecular mechanism still need further study. Translocator protein 18 kDa (TSPO) is a vital therapeutic target for pain treatment, and recent research implies that there may be allostery in TSPO. Our previous competitive binding assay hint that koumine may function as a TSPO positive allosteric modulator (PAM). Here, for the first time, we report the pharmacological characterization of koumine as a TSPO PAM. The results imply that koumine might be a high-affinity ligand of TSPO and that it likely acts as a PAM since it could delay the dissociation of ³H-PK11195 from TSPO. Importantly, the allostery was retained in vivo, as koumine augmented Ro5-4864-mediated analgesic and anti-inflammatory effects in several acute and chronic inflammatory and neuropathic pain models. Moreover, the positive allosteric modulatory effect of koumine on TSPO was further demonstrated in cell proliferation assays in T98G human glioblastoma cells. In summary, we have identified and characterized koumine as a TSPO PAM for the treatment of inflammatory and neuropathic pain. Our data lay a solid foundation for the use of the clinical candidate koumine to treat inflammatory and neuropathic pain, further demonstrate the allostery in TSPO, and provide the first proof of principle that TSPO PAM may be a novel avenue for the discovery of analgesics.

Koumine Suppresses IL-1β Secretion and Attenuates Inflammation Associated With Blocking ROS/NF-κB/NLRP3 Axis in Macrophages

Koumine (KM), one of the primary constituents of Gelsemium elegans, has been used for the treatment of inflammatory diseases such as rheumatoid arthritis, but whether KM impacts the activation of the NOD-like receptor protein 3 (NLRP3) inflammasome remains unknown. This study aimed to explore the inhibitory effect of KM on NLRP3 inflammasome activation and the underlying mechanisms both in vitro using macrophages stimulated with LPS plus ATP, nigericin or monosodium urate (MSU) crystals and in vivo using an MSU-induced peritonitis model. We found that KM dose-dependently inhibited IL-1β secretion in macrophages after NLRP3 inflammasome activators stimulation. Furthermore, KM treatment efficiently attenuated the infiltration of neutrophils and suppressed IL-1β production in mice with MSU-induced peritonitis. These results indicated that KM inhibited NLRP3 inflammasome activation, and consistent with this finding, KM effectively inhibited caspase-1 activation, mature IL-1β secretion, NLRP3 formation and pro-IL-1β expression in LPS-primed macrophages treated with ATP, nigericin or MSU. The mechanistic study showed that, KM exerted a potent inhibitory effect on the NLRP3 priming step, which decreased the phosphorylation of IκBα and p65, the nuclear localization of p65, and the secretion of TNF-α and IL-6. Moreover, the assembly of NLRP3 was also interrupted by KM. KM blocked apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and its oligomerization and hampered the NLRP3-ASC interaction. This suppression was attributed to the ability of KM to inhibit the production of reactive oxygen species (ROS). In support of this finding, the inhibitory effect of KM on ROS production was completely counteracted by H₂O₂, an ROS promoter. Our results provide the first indication that KM exerts an inhibitory effect on NLRP3 inflammasome activation associated with blocking the ROS/NF-κB/NLRP3 signal axis. KM might have potential clinical application in the treatment of NLRP3 inflammasome-related diseases.

An Integrated Network, RNA Sequencing, and Experiment Pharmacology Approach Reveals the Active Component, Potential Target, and Mechanism of Gelsemium elegans in the Treatment of Colorectal Cancer

In this study, a combination of network pharmacology, bioinformatics analysis, molecular docking and transcriptomics was used to investigate the active ingredient and potential target of Gelsemium elegans in the treatment of colorectal cancer. Koumine was screened as the active component by targeting PDK1 through network pharmacology and reverse docking. RNA-Seq, enrichment analysis and validation experiment were then further employed to reveal koumine might function in inhibiting Akt/mTOR/HK2 pathway to regulate cell glycolysis and detachment of HK2 from mitochondria and VDAC-1 to activate cell apoptosis both in vitro and in vivo. In the present study, we provide a systematical approach for the identification of effective ingredient and potential target of herbal medicine. Our results have important implication for the intensive study of koumine as novel anticancer agents for colorectal cancer and could be supportive in its further structural modification.

Prenatal exposure to koumine results in cognitive deficits and increased anxiety-like behavior in mice offspring

Koumine (KM) is a major alkaloid monomer in the traditional Chinese medicine herb Gelsemium elegans Benth that has exhibited therapeutic potential in clinical applications. However, the pharmacological toxicological mechanism of this drug has not been fully explored. The purpose of this study was to evaluate the impacts of KM administration at a therapeutic dose in offspring. On gestational day 0, mice were injected with KM once daily for 4 consecutive days. Male and female offspring were subjected to behavioral tests and neuropathological analyses from postnatal day 60. Prenatal KM exposure resulted in cognitive and memory impairments in the Morris water maze, Y-maze test, and novel object recognition test. The open field test and elevated plus maze test indicated that prenatal KM exposure induced anxiety-like behavior in offspring. Electrophysiological experiments demonstrated that KM exposure inhibited hippocampal long-term potentiation. Immunostaining for neurogenesis markers DCX and BrdU demonstrated that KM suppressed adult neurogenesis in the subgranular zone of the dentate gyrus. In addition, prenatal KM exposure induced a significant reduction in dendritic spine density in hippocampal neurons. Synaptic formation-related proteins were decreased in the KM group based on western blot. No sex differences in the effects of KM were observed. Collectively, our results indicate that prenatal KA exposure has detrimental neural effects on offspring. This study provides a preliminary preclinical toxicological assessment of the safety of KM use during pregnancy.

Gene expression profile analysis of ileum transcriptomes in pigs fed Gelsemium elegans plants

Gelsemium elegans is a flowering plant in the Loganiaceae. Because it can promote the growth of pigs and sheep, it is widely used, including in veterinary clinics, but little information is available about its biological effects. Here, we used high-throughput sequencing to characterize the differentially expressed genes (DEGs) in the ileums of pigs between a control group and a group fed Gelsemium elegans for 45 days. We found that Gelsemium elegans affected many inflammatory and immune pathways, including biological processes such as defense responses, inflammation and immune responses. Moreover, this study identified several important genes related to the anti-inflammatory activity of Gelsemium elegans (e.g., CXCL-8, IL1A, and CSF2), which will be beneficial for further study of the pharmacological mechanisms and clinical applications of Gelsemium elegans.

Koumine Promotes ROS Production to Suppress Hepatocellular Carcinoma Cell Proliferation Via NF-κB and ERK/p38 MAPK Signaling

In the past decades, hepatocellular carcinoma (HCC) has been receiving increased attention due to rising morbidity and mortality in both developing and developed countries. Koumine, one of the significant alkaloidal constituents of Gelsemium elegans Benth., has been regarded as a promising anti-inflammation, anxiolytic, and analgesic agent, as well as an anti-tumor agent. In the present study, we attempted to provide a novel mechanism by which koumine suppresses HCC cell proliferation. We demonstrated that koumine might suppress the proliferation of HCC cells and promote apoptosis in HCC cells dose-dependently. Under koumine treatment, the mitochondria membrane potential was significantly decreased while reactive oxygen species (ROS) production was increased in HCC cells; in the meantime, the phosphorylation of ERK, p38, p65, and IκBα could all be inhibited by koumine treatment dose-dependently. More importantly, the effects of koumine upon mitochondria membrane potential, ROS production, and the phosphorylation of ERK, p38, p65, and IκBα could be significantly reversed by ROS inhibitor, indicating that koumine affects HCC cell fate and ERK/p38 MAPK and NF-κB signaling activity through producing excess ROS. In conclusion, koumine could inhibit the proliferation of HCC cells and promote apoptosis in HCC cells; NF-κB and ERK/p38 MAPK pathways could contribute to koumine functions in a ROS-dependent manner.

Simultaneous Determination of Koumine and Gelsemine in Human Plasma Using HPLC-UV Assay and Its Clinical Application

Background:

Of two main alkaloids extracted from Gelsemium, koumine was shown to be a promising analgesic, while gelsemine proved to be deleterious. Many patients suspected to be poisoned by Gelsemium cannot be timely diagnosed due to the lack of UPLC-MS/MS. Additionally, the concentration of alkaloids in humans has never been reported. The aim of this study was to establish a more economical and accessible method using HPLC-UV for diagnosis and quantitative analysis of Gelsemium poisoning.

Methods:

Plasma spiked with an internal standard, oxcarbazepine, was prepared with solid-phase extraction. Koumine and gelsemine were separated on a C18 column using a mobile phase consisting of methanol, water, and di-n-butylamine (58:42:0.01) pumped at a flow rate of 1.00 mL/min. The detection wavelength was set at 263 nm. Plasma concentrations of two different times were determined for the patients.

Results:

The calibration curves for both monomers possessed good linearity from 0.05-50 mg/L (r=0.9997 and 0.9999, respectively). The extraction recoveries were greater than 88.5 %. Variation for intraday and interday assays of koumine and gelsemine were less than 8.3% and 7.7%, respectively. The concentrations of the two alkaloids were identified in 5 patients with Gelsemium poisoning by using the established method.

Conclusion:

The established method by using HPLC-UV is applicable for diagnosis and quantitative analysis of Gelsemium poisoning in such cases. TDM of koumine and gelsemine in patients with Gelsemium poisoning may provide additional information for the clinic to improve rescue strategy.

Koumine Decreases Astrocyte-Mediated Neuroinflammation and Enhances Autophagy, Contributing to Neuropathic Pain From Chronic Constriction Injury in Rats

Koumine, an indole alkaloid, is a major bioactive component of Gelsemium elegans. Previous studies have demonstrated that koumine has noticeable anti-inflammatory and analgesic effects in inflammatory and neuropathic pain (NP) models, but the mechanisms involved are not well understood. This study was designed to explore the analgesic effect of koumine on chronic constriction injury (CCI)-induced NP in rats and the underlying mechanisms, including astrocyte autophagy and apoptosis in the spinal cord. Rats with CCI-induced NP were used to evaluate the analgesic and anti-inflammatory effects of koumine. Lipopolysaccharide (LPS)-induced inflammation in rat primary astrocytes was also used to evaluate the anti-inflammatory effect of koumine. We found that repeated treatment with koumine significantly reduced and inhibited CCI-evoked astrocyte activation as well as the levels of pro-inflammatory cytokines. Meanwhile, we found that koumine promoted autophagy in the spinal cord of CCI rats, as reflected by decreases in the LC3-II/I ratio and P62 expression. Double immunofluorescence staining showed a high level of colocalization between LC3 and GFAP-positive glia cells, which could be decreased by koumine. Intrathecal injection of an autophagy inhibitor (chloroquine) reversed the analgesic effect of koumine, as well as the inhibitory effect of koumine on astrocyte activation in the spinal cord. In addition, TUNEL staining suggested that CCI-induced apoptosis was inhibited by koumine, and this inhibition could be abolished by chloroquine. Western blot analysis revealed that koumine significantly increased the level of Bcl-xl while inhibiting Bax expression and decreasing cleaved caspase-3. In addition, we found that koumine could decrease astrocyte-mediated neuroinflammation and enhance autophagy in primary cultured astrocytes. These results suggest that the analgesic effects of koumine on CCI-induced NP may involve inhibition of astrocyte activation and pro-inflammatory cytokine release, which may relate to the promotion of astrocyte autophagy and the inhibition for apoptosis in the spinal cord.