koumine and Inflammation

Gelsemium elegans (Gardner & Chapm.) Benth (G. elegans) has been widely used as a traditional folk medicine in China and Southeast Asia. As the most abundant alkaloid in G. elegans, Koumine (KM) has been revealed the effect of inflammatory attenuation modulating by macrophage activation and polarization.. This study aimed to explore the effect of KM on modulation of microglia polarization that led to the suppression of neuroinflammation and further improved neurodegenerative behavior.. Inflammatory mediators, microglia M1 and M2 phenotype markers and Nrf2/HO-1 pathway related protein were assessed in LPS-induced BV2 cells and LPS-treated mice by RT-PCR, immunohistochemistry, immunofluorescence and Western blotting. Moreover, the learning and memory abilities of mice were evaluated by Morris water maze test, and the neuronal damage was evaluated by the Nissl staining.. KM attenuated LPS-induced viability and morphological changes in BV2 microglial cells. Our findings showed that KM activated the Nrf2/HO-1 signaling pathway to promote phenotypic switch from M1 to M2 phenotypes. This switch suppresses the release of inflammatory mediators in LPS-induced BV2 cells. Meanwhile, KM attenuated neuroinflammation through modulating microglia polarization and subsequently reversed the behavioral alterations in LPS-induced mice model of neuroinflammation.. KM may alleviate neuroinflammation by regulating microglia polarization with the involvement of Nrf2/HO-1 pathway, resulting of the neuroprotective effect.

Topics: Animals; Inflammation; Inflammation Mediators; Lipopolysaccharides; Mice; Microglia; Neuroinflammatory Diseases; NF-E2-Related Factor 2

Gelsemium elegans Benth. is a toxic plant that has been used as an ancient Chinese herbal remedy for rheumatoid arthritis (RA) and nervous pain, spasticity, skin ulcers, and cancers. Koumine, one of its representative alkaloids, shows numerous promising pharmacological activities, including anti-inflammatory and analgesic activities. Here, we investigated the analgesic effect of koumine on the collagen-induced arthritis (CIA) rat model of RA and explored the potential pharmacological mechanisms underlying the analgesia. In the CIA rats, repeated koumine treatments significantly reduced pain compared to controls and attenuated the collagen-induced increase in levels of glial fibrillary acidic protein (GFAP) and the pro-inflammatory cytokines tumour necrosis factor α (TNF-α) and interleukin 1β (IL-1β). Cultured astrocytes showed reduced astrocyte reactivation and decreased production of both tested cytokines. Based on our results, koumine exerted both analgesic and anti-inflammatory effects on the CIA rat model that were apparently mediated by inhibiting astrocyte reactivation and pro-inflammatory cytokine production.

Topics: Analgesics; Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Collagen; Disease Models, Animal; Drugs, Chinese Herbal; Indole Alkaloids; Inflammation; Male; Rats; Rats, Wistar

Despite decades of studies, the currently available drugs largely fail to control neuropathic pain. Koumine-an alkaloidal constituent derived from the medicinal plant

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Astrocytes; Carrier Proteins; Cell Line; Indole Alkaloids; Inflammation; Male; Microglia; Neuralgia; Rats, Sprague-Dawley; Receptors, GABA-A; Sciatic Nerve; Spinal Cord

Crude alkaloidal extraction from Gelsemium elegans Benth. produces analgesic property. However, its clinical utility has been obstructed by its narrow therapeutic index. Here, we investigated the potential of koumine, a monomer of Gelsemium alkaloids, to reduce both inflammatory and neuropathic pain. Interestingly, allopregnanolone, a neurosteroid, appeared to mediate the reduction of neuropathic pain. The potential anti-inflammatory pain effects of koumine were evaluated by acetic acid-, formalin- and complete Freund's adjuvant (CFA) -induced nociceptive behaviors in mice. Chronic constriction injury (CCI) and L5 spinal nerve ligation (L5 SNL), inducing thermal hyperalgesia and mechanical allodynia in rats, were used to test whether repeated treatment of koumine ameliorated neuropathic pain. Finally, we explored if koumine altered the level of neurosteroids in rat spinal cord of CCI neuropathy using liquid chromatography-tandem mass spectrometry. Koumine dose-dependently reduced the acetic acid-induced writhes and formalin-induced licking/biting time of Phase II in mice. Repeated administrations of koumine also dose-dependently reversed the CFA-, CCI- and L5 SNL-induced thermal hyperalgesia, as well as, CCI- and L5 SNL-induced mechanical allodynia in rats. The level of allopregnanolone, but not pregnenolone, in the L5-6 spinal cord was elevated by repeated treatment of koumine in CCI-induced neuropathic rats. These results demonstrate that koumine has a significant analgesic effect in rodent behavioral models of inflammatory and neuropathic pain, and that the reduction in neuropathic pain may be associated with the upregulation of allopregnanolone in the spinal cord.

Topics: Analgesics; Animals; Disease Models, Animal; Gelsemium; Hyperalgesia; Indole Alkaloids; Inflammation; Male; Mice; Mice, Inbred ICR; Neuralgia; Pain; Pain Measurement; Pregnanolone; Rats; Rats, Sprague-Dawley; Spinal Cord; Up-Regulation