Gelsemium elegans Benth: Chemical Components, Pharmacological Effects, and Toxicity Mechanisms

Monoterpene indole alkaloids from Gelsemium elegans

Two new monoterpene indole alkaloids, Eleganine A (1) and Eleganine B (2), along with 11 known compounds (3-13) were isolated from the stems and leaves of Gelsemium elegans. Compound 1 is a gelsenicine-related monoterpenoid indole alkaloid possessing an iridoid unit. Their structures and absolute configurations of 1-2 were established by UV, IR, HR-ESI-MS, NMR spectroscopy, and electronic circular dichroism data analyses. All isolated compounds were evaluated for their anti-inflammatory and inhibiting glucose-induced mesanginal cell proliferation activities. None of them showed activity with IC50 far beyond 50 μM.

Pharmacological effects of koumine on acute lung injury in septic mice: From in vivo experiments and network pharmacology studies

Acute lung injury (ALI) caused by sepsis is one of the most common critical diseases, which is difficult to treat and has a high fatality rate. Koumine is one of the main active components of Gelsemium plants and has been confirmed to have potential for drug development; however, its therapeutic effects on ALI have not yet been studied. This study established ALI due to sepsis using cecal ligation and puncture (CLP) and assessed the therapeutic effects of koumine by measuring mouse survival rates, lung tissue pathological damage, inflammatory factors, and oxidative stress levels. Additionally, network pharmacology was utilized to explore the underlying mechanisms. The results showed that koumine inhibited the release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β), thereby inhibiting inflammatory response, reducing lung injury score and lung wet to dry ratio. In addition, koumine reduced oxidative stress in mice by reducing myeloperoxidase (MPO) and malondialdehyde (MDA) and increasing superoxide dismutase (SOD) content. Network pharmacology analysis showed that 52 putative targets were relevant, and SLC6A4, HTR3A, JAK2 and JAK3 were the key targets. GO and KEGG pathway enrichment analysis showed that the related mechanisms involved neuroactive ligand-receptor interaction, calcium signaling pathway, serotonergic synapses, cholinergic synapses, etc. In summary, this study confirmed the potential therapeutic effect of koumine in sepsis induced ALI, suggesting its development prospect as a novel candidate drug for ALI, and providing data support.

Metabolomics Characterization of Chemical Composition and Bioactivity of Highland Barley Monascus Tea Decoction Before and After Simulated Digestion In Vitro

A broadly targeted metabolomics approach based on UPLC-MS/MS was employed to investigate the changes in chemical composition and in vitro activity of highland barley Monascus tea decoction before and after simulated digestion. The characteristic metabolites of the tea decoction before and after in vitro-simulated digestion were identified, and the in vitro antioxidant and enzyme inhibitory activities of the tea decoction were further analyzed. The study detected 1431 metabolites, including amino acids and their derivatives, alkaloids, organic acids, nucleotides and their derivatives, lipids, terpenoids, and phenolic acids. A total of 136 differential compounds were identified, primarily distributed in amino acids and their derivatives, alkaloids, organic acids, phenolics, and lipids. in vitro-simulated digestion significantly increased the content of amino acids, alkaloids, lipids, and phenolics in the tea. The differential metabolic compounds were primarily assigned to 20 metabolic pathways, mainly involving the metabolism of amino acids, nucleotides, carbohydrates, fatty acids, and other compounds. Additionally, after simulated digestion in vitro, the comprehensive antioxidant index (60.53%), α-glucosidase inhibitory activity (54.35%), and pancreatic lipase inhibitory activity (4.06%) was significantly improved. The highland barley Monascus tea decoction showed potential hypoglycemic and hypolipidemic efficacy. This study can provide a theoretical basis for the high-value utilization of highland barley and the development of healthy grain tea.

Insights on neuropharmacological benefits and risks: Aconitum carmichaelii Debx

Aconitum carmichaelii Debx., a traditional herb known for its potent bioactivities, has been widely used in Traditional Chinese Medicine, particularly in the forms of Chuanwu and Fuzi. Despite the therapeutic benefits of this plant, concerns have been raised regarding its neuropharmacological actions and potential neurotoxicity. This paper provides an in-depth analysis of the neuropharmacological effects, neurotoxicological mechanisms, and toxicity biomarkers of Aconitum roots. The neuropharmacological properties are linked to alterations in neurotransmitter synthesis and ion transport modulation, while the neurotoxic effects are primarily attributed to oxidative stress responses and the induction of mitochondrial apoptosis pathways. Through metabolomic profiling, we have identified several metabolic pathways affected by Aconitum roots, with a significant impact on tryptophan metabolism, which in turn influences cardiovascular and nervous system functions, liver detoxification, and energy metabolism. Furthermore, we discuss the modulation of ion channel protein activity, which is evidenced by recent studies, suggesting a critical role in the neurotoxic effects of Aconitum. An early detection strategy for toxicity biomarkers using metabonomics is proposed, emphasizing its crucial role in enhancing the diagnosis and treatment of Aconitum poisoning. It is recommended that regular monitoring of individuals at risk of Aconitum toxicity, including habitual consumers of TCM and accidental ingestion of the plant, be conducted in order to prevent toxic outcomes. This review emphasizes the importance of understanding the dual nature of Aconitum as both a therapeutic agent and a potential neurotoxin, aiming to optimize its clinical use and ensure patient safety.

A toxicological review of alkaloids

Alkaloids are naturally occurring compounds with complex structures found in natural plants. To further improve the understanding of plant alkaloids, this review focuses on the classification, toxicity and mechanisms of action, providing insight into the occurrence of alkaloid-poisoning events and guiding the safe use of alkaloids in food, supplements and clinical applications. Based on their chemical structure, alkaloids can be divided into organic amines, diterpenoids, pyridines, isoquinolines, indoles, pyrrolidines, steroids, imidazoles and purines. The mechanisms of toxicity of alkaloids, including neurotoxicity, hepatoxicity, nephrotoxicity, cardiotoxicity and cytotoxicity, have also been reviewed. Some cases of alkaloid poisoning have been introduced when used as food or clinically, including accidental food poisoning, excessive consumption, and poisoning caused by the improper use of alkaloids in a clinical setting, and the importance of safety evaluation was illustrated. This review summarizes the toxicity and mechanism of action of alkaloids and provides evidence for the need for the safe use of alkaloids in food, supplements and clinical applications.

It Is Not All about Alkaloids-Overlooked Secondary Constituents in Roots and Rhizomes of Gelsemium sempervirens (L.) J.St.-Hil

Gelsemium sempervirens (L.) J.St.-Hil. is an evergreen shrub occurring naturally in North and Middle America. So far, more than 120 alkaloids have been identified in this plant in addition to steroids, coumarins and iridoids, and its use in traditional medicine has been traced back to these compound classes. However, a comprehensive phytochemical investigation of the plant with a special focus on further compound classes has not yet been performed. Therefore, the present study aimed at an extensive HPLC-MSn characterization of secondary metabolites and, for the first time, reports the occurrence of various depsides and phenolic glycerides in G. sempervirens roots and rhizomes, consisting of benzoic and cinnamic acid derivatives as well as dicarboxylic acids. Furthermore, mono- and disaccharides were assigned by GC-MS. Applying the Folin-Ciocalteu assay, the phenolic content of extracts obtained with different solvents was estimated to range from 30 to 50% calculated as chlorogenic acid equivalents per g dry weight and was related to the DPPH radical scavenging activity of the respective extracts. Upon lactic acid fermentation of aqueous G. sempervirens extracts, degradation of phenolic esters was observed going along with the formation of low-molecular volatile metabolites.

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.

Design, semi-synthesis and bioevaluation of koumine-like derivatives as potential antitumor agents in vitro and in vivo

Aims: Five series of novel koumine-like compounds were designed, semi-synthesized and systematically evaluated for antitumor activities.Methods: All compounds were evaluated for antiproliferative activity against four human cancer cell lines, including HT-29, HCT-116, HCT-15 and Caco-2.Results: Most compounds exhibited much higher antiproliferation activities (IC50 <10 μM) than koumine. Two selected compounds A4 and C5 showed comparable antitumor effects to 5-FU in vivo, as well as better safety profiles. Further studies suggested that A4 and C5 could arrest HT-29 cell cycle in G2 phase and raise reactive oxygen species level, thus inducing cell apoptosis related to Erk MAPK and NF-κB signaling pathways inhibition.Conclusion: These results will greatly promote the druggability study of these koumine-like compounds.

Identification of toxic Gelsemium elegans in processed food and honey based on real-time PCR analysis

Gelsemium elegans (GE) is a widely distributed hypertoxic plant that has caused many food poisoning incidents. Its pollen can also be collected by bees to produce toxic honey, posing a great threat to the health and safety of consumers. However, for the complex matrices such as cooked food and honey, it is challenging to perform composition analysis. It is necessary to establish more effective strategies for investigating GE contamination. In this study, the real-time PCR (qPCR) analysis combined with DNA barcode matK was proposed for the identification and detection of GE. Fifteen honey samples along with twenty-eight individuals of GE and the common confusable objects Lonicera japonica, Ficus hirta, Stellera chamaejasme and Chelidonium majus were gathered. Additionally, the food mixtures treated with 20-min boiling and 30-min digestion were prepared. Specific primers were designed, and the detection capability and sensitivity of qPCR in honey and boiled and digested food matrices were tested. The results demonstrated that the matK sequence with sufficient mutation sites was an effective molecular marker for species differentiation. GE and the confusable species could be clearly classified by the fluorescence signal of qPCR assay with a high sensitivity of 0.001 ng/μl. In addition, this method was successfully employed for the detection of deeply processed food materials and honey containing GE plants which even accounted for only 0.1 %. The sequencing-free qPCR approach undoubtedly can serve as a robust support for the quality supervision of honey industry and the prevention and diagnosis of food poisoning.

Effects of different combinations of koumine and gelsemine on growth performance, intestinal health, and transcriptome of Cyprinus carpio

Koumine (KM) and gelsemine (GS) have shown significant benefits in livestock production, but their potential in aquaculture remains largely unexplored. This study examined the impact of different KM and GS combinations as feed additives on C. carpio (90 fish per group, initial weight 1.95 ± 0.08 g). KM and GS were introduced in ratios of 2:2 (mg/kg), 2:1 (mg/kg), and 2:0.67 (mg/kg) over a 10-week aquaculture experiment. The results demonstrate that the 2:1 (mg/kg) group increases the villus length, muscular layer thickness, crude protein, and crude fat content. Regarding fatty acid content, KM and GS enhance the levels of various fatty acids, including the total saturated fatty acid and total monounsaturated fatty acid. Additionally, KM and GS improve the composition and function of the intestinal microbiota. The 2:1 (mg/kg) group significantly elevates the enzymatic activities of SOD, MDA, CAT and upregulates the expression of immune-related genes such as toll-like receptor 2, transforming growth factor β, and glutathione S-transferase. Transcriptomic analysis suggests that KM and GS may have potential benefits for nutrient utilization and immune regulation in C. carpio. In summary, this study provides valuable insights into the use of KM and GS as feed additives in aquaculture.

Molecular identification and functional characterization of a transcription factor GeRAV1 from Gelsemium elegans

BACKGROUND

Gelsemium elegans is a traditional Chinese medicinal plant and temperature is one of the key factors affecting its growth. RAV (related to ABI3/VP1) transcription factor plays multiple roles in higher plants, including the regulation of plant growth, development, and stress response. However, RAV transcription factor in G. elegans has not been reported.

RESULTS

In this study, three novel GeRAV genes (GeRAV1-GeRAV3) were identified from the transcriptome of G. elegans under low temperature stress. Phylogenetic analysis showed that GeRAV1-GeRAV3 proteins were clustered into groups II, IV, and V, respectively. RNA-sequencing (RNA-seq) and real-time quantitative PCR (qRT-PCR) analyses indicated that the expression of GeRAV1 and GeRAV2 was increased in response to cold stress. Furthermore, the GeRAV1 gene was successfully cloned from G. elegans leaf. It encoded a hydrophilic, unstable, and non-secretory protein that contained both AP2 and B3 domains. The amino acid sequence of GeRAV1 protein shared a high similarity of 81.97% with Camptotheca acuminata CaRAV. Subcellular localization and transcriptional self-activation experiments demonstrated that GeRAV1 was a nucleoprotein without self-activating activity. The GeRAV1 gene was constitutively expressed in the leaves, stems, and roots of the G. elegans, with the highest expression levels in roots. In addition, the expression of the GeRAV1 gene was rapidly up-regulated under abscisic acid (ABA), salicylic acid (SA), and methyl jasmonate (MeJA) stresses, suggesting that it may be involved in hormonal signaling pathways. Moreover, GeRAV1 conferred improved cold and sodium chloride tolerance in Escherichia coli Rosetta cells.

CONCLUSIONS

These findings provided a foundation for further understanding on the function and regulatory mechanism of the GeRAV1 gene in response to low-temperature stress in G. elegans.

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.

Reference Genes Screening and Gene Expression Patterns Analysis Involved in Gelsenicine Biosynthesis under Different Hormone Treatments in Gelsemium elegans

Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is an accurate method for quantifying gene expression levels. Choosing appropriate reference genes to normalize the data is essential for reducing errors. Gelsemium elegans is a highly poisonous but important medicinal plant used for analgesic and anti-swelling purposes. Gelsenicine is one of the vital active ingredients, and its biosynthesis pathway remains to be determined. In this study, G. elegans leaf tissue with and without the application of one of four hormones (SA, MeJA, ETH, and ABA) known to affect gelsenicine synthesis, was analyzed using ten candidate reference genes. The gene stability was evaluated using GeNorm, NormFinder, BestKeeper, ∆CT, and RefFinder. The results showed that the optimal stable reference genes varied among the different treatments and that at least two reference genes were required for accurate quantification. The expression patterns of 15 genes related to the gelsenicine upstream biosynthesis pathway was determined by RT-qPCR using the relevant reference genes identified. Three genes 8-HGO, LAMT, and STR, were found to have a strong correlation with the amount of gelsenicine measured in the different samples. This research is the first study to examine the reference genes of G. elegans under different hormone treatments and will be useful for future molecular analyses of this medically important plant species.

Effect of Dietary Gelsemium elegans Benth. Extract on the Growth, Slaughter Performance, Meat Quality, Intestinal Morphology, and Microflora of Yellow-Feathered Chickens

The plant species Gelsemium elegans Benth. (GEB) promotes pig and sheep growth; however, little is known about its effects in chickens. In this study, a GEB extract (GEBE) was prepared, and its effects on the growth, slaughter, antioxidant performance, meat quality, serum biochemical indices, intestinal morphology, and microflora of yellow-feathered chickens were evaluated. In total, 600 chickens aged 15 days were randomly divided into four groups with five replicates each and fed a basal diet containing 0% (control), 0.25% (0.25 GEBE), 0.75% (0.75 GEBE), or 1.25% (1.25 GEBE) GEBE until 49 days of age. Chickens were then killed, and their meat, organs, and serum and cecal contents were collected. GEBE reduced the feed conversion ratio, particularly in the 0.75 and 1.25 GEBE groups. Furthermore, the GEBE diet improved meat tenderness and reduced the meat expressible moisture content and liver malondialdehyde content, indicating high meat quality. Whereas the 0.25 GEBE diet increased the level of Lactobacillus acidophilus in the cecum, the 0.75 GEBE diet decreased the Escherichia coli level therein. These findings demonstrate that GEBE may improve the meat quality and cecal microbiota of yellow-feathered chickens, providing a basis for identifying candidate alternatives to conventional antibiotics as growth promoting feed additives.

Modulation of GABAA receptors and of GABAergic synapses by the natural alkaloid gelsemine

The Gelsemium elegans plant preparations have shown beneficial activity against common diseases, including chronic pain and anxiety. Nevertheless, their clinical uses are limited by their toxicity. Gelsemine, one of the most abundant alkaloids in the Gelsemium plants, have replicated these therapeutic and toxic actions in experimental behavioral models. However, the molecular targets underlying these biological effects remain unclear. The behavioral activity profile of gelsemine suggests the involvement of GABA_A receptors (GABA_ARs), which are the main biological targets of benzodiazepines (BDZs), a group of drugs with anxiolytic, hypnotic, and analgesic properties. Here, we aim to define the modulation of GABA_ARs by gelsemine, with a special focus on the subtypes involved in the BDZ actions. The gelsemine actions were determined by electrophysiological recordings of recombinant GABA_ARs expressed in HEK293 cells, and of native receptors in cortical neurons. Gelsemine inhibited the agonist-evoked currents of recombinant and native receptors. The functional inhibition was not associated with the BDZ binding site. We determined in addition that gelsemine diminished the frequency of GABAergic synaptic events, likely through a presynaptic modulation. Our findings establish gelsemine as a negative modulator of GABA_ARs and of GABAergic synaptic function. These pharmacological features discard direct anxiolytic or analgesic actions of gelsemine through GABA_ARs but support a role of GABA_ARs on the alkaloid induced toxicity. On the other hand, the presynaptic effects of the alkaloid provide an additional mechanism to explain their beneficial effects. Collectively, our results contribute novel information to improve understanding of gelsemine actions in the mammalian nervous system.

Regulation of microglia related neuroinflammation contributes to the protective effect of Gelsevirine on ischemic stroke

Stroke, especially ischemic stroke, is an important cause of neurological morbidity and mortality worldwide. Growing evidence suggests that the immune system plays an intricate function in the pathophysiology of stroke. Gelsevirine (Gs), an alkaloid from Gelsemium elegans, has been proven to decrease inflammation and neuralgia in osteoarthritis previously, but its role in stroke is unknown. In this study, the middle cerebral artery occlusion (MCAO) mice model was used to evaluate the protective effect of Gs on stroke, and the administration of Gs significantly improved infarct volume, Bederson score, neurobiological function, apoptosis of neurons, and inflammation state in vivo. According to the data in vivo and the conditioned medium (CM) stimulated model in vitro, the beneficial effect of Gs came from the downregulation of the over-activity of microglia, such as the generation of inflammatory factors, dysfunction of mitochondria, production of ROS and so on. By RNA-seq analysis and Western-blot analysis, the JAK-STAT signal pathway plays a critical role in the anti-inflammatory effect of Gs. According to the results of molecular docking, inhibition assay, and thermal shift assay, the binding of Gs on JAK2 inhibited the activity of JAK2 which inhibited the over-activity of JAK2 and downregulated the phosphorylation of STAT3. Over-expression of a gain-of-function STAT3 mutation (K392R) abolished the beneficial effects of Gs. So, the downregulation of JAK2-STAT3 signaling pathway by Gs contributed to its anti-inflammatory effect on microglia in stroke. Our study revealed that Gs was benefit to stroke treatment by decreasing neuroinflammation in stroke as a potential drug candidate regulating the JAK2-STAT3 signal pathway.

Koumine ameliorates concanavalin A-induced autoimmune hepatitis in mice: involvement of the Nrf2, NF-κB pathways, and gut microbiota

Gelsemiumelegans(Gardner. & Chapm.) Benth. has long been considered a traditional Chinese medicine effective against rheumatoid pain, cancer, cirrhosis, and skin diseases. Koumine (KM), the most abundant alkaloid in G.elegans Benth., demonstrates a variety of biological effects, including antitumor, analgesic, anxiolytic, anti-inflammatory, antidepressant, antioxidant, immunoregulatory, and hepatoprotective effects. Furthermore, the relatively low toxicity of KM makes it a promising drug candidate. This study aimed to investigate the protective effects of KM and its possible mechanisms using a concanavalin A (Con A)-induced autoimmune hepatitis (AIH) model in mice. Mice were orally administered different doses of KM for 14 d before Con A tail vein injections. The effects of KM on serum biochemical markers and liver histopathology were then evaluated 12 h after Con A exposure. The Nrf2 and NF-κB signaling pathways and alterations in gut microbiota were determined using western blotting, immunohistochemistry, and 16S rRNA sequencing to explore the underlying mechanisms of KM exposure. KM pretreatment dose-dependently decreased serum liver injury markers (Alanine aminotransferase, and aspartate aminotransferase) and cytokine levels (Tumor necrosis factor-α and interleukin-6), as well as the liver pathological damage triggered by Con A. Furthermore, the results of the multi-technique analysis indicated that KM activated the Nrf2 pathway, upregulated the expression of anti-oxidation factors HO-1 and Nrf2, and downregulated the expression of Keap1. Moreover, the NF-κB signaling pathway was inhibited. Interestingly, pre-treatment with KM also significantly improved the composition of the gut microbiota probably because it increases the richness of probiotics. Our findings suggest that KM pretreatment could attenuate Con A-induced AIH, the Nrf2 and NF-κB signaling pathways, and that gut microbiota are involved in the process of the hepatoprotective effect. This study provides a theoretical basis for the development of KM as an effective agent against AIH.

Assembly of the Complete Mitochondrial Genome of Gelsemium elegans Revealed the Existence of Homologous Conformations Generated by a Repeat Mediated Recombination

Gelsemium elegans (G. elegans) is a Chinese medicinal plant with substantial economic and feeding values. There is a lack of detailed studies on the mitochondrial genome of G. elegans. In this study, the mitochondrial genome of G. elegans was sequenced and assembled, and its substructure was investigated. The mitochondrial genome of G. elegans is represented by two circular chromosomes of 406,009 bp in length with 33 annotated protein-coding genes, 15 tRNA genes, and three rRNA genes. We detected 145 pairs of repeats and found that four pairs of repeats could mediate the homologous recombination into one major conformation and five minor conformations, and the presence of conformations was verified by PCR amplification and Sanger sequencing. A total of 124 SSRs were identified in the G. elegans mitochondrial genome. The homologous segments between the chloroplast and mitochondrial genomes accounted for 5.85% of the mitochondrial genome. We also predicted 477 RNA potential editing sites and found that the nad4 gene was edited 38 times, which was the most frequent occurrence. Taken together, the mitochondrial genome of G. elegans was assembled and annotated. We gained a more comprehensive understanding on the genome of this medicinal plant, which is vital for its effective utilization and genetic improvement, especially for cytoplasmic male sterility breeding and evolution analysis in G. elegans.

Effects of Dietary Koumine on Growth Performance, Intestinal Morphology, Microbiota, and Intestinal Transcriptional Responses of Cyprinus carpio

Gelsemium elegans Benth. (GEB) is a traditional medicinal plant in China, and acts as a growth promoter in pigs and goats. Koumine (KM) is the most abundant alkaloid in GEB and produces analgesic, anti-cancer, and immunomodulatory effects. KM can be used as an aquatic immune stimulant, but its growth-promoting effects and transcriptional mechanisms have not been investigated. Diets containing KM at 0, 0.2, 2, and 20 mg/kg were fed to Cyprinus carpio for 71 days to investigate its effects on growth performance, intestinal morphology, microflora, biochemical indicators, and transcriptional mechanisms. Cyprinus carpio fed with KM as the growth promoter, and the number of intestinal crypts and intestinal microbial populations were influenced by KM concentration. KM increased the abundance of colonies of Afipia, Phyllobacterium, Mesorhizobium, and Labrys, which were associated with compound decomposition and proliferation, and decreased the abundance of colonies of pathogenic bacteria Methylobacterium-Methylorubrum. A total of 376 differentially-expressed genes (DEGs) among the four experimental groups were enriched for transforming growth factor-β1 and small mother against decapentaplegic (TGF-β1/Smad), mitogen-activated protein kinase (MAPK), and janus kinases and signal transducers and activators of transcription (Jak/Stat) signaling pathways. In particular, tgfbr1, acvr1l, rreb-1, stat5b, smad4, cbp, and c-fos were up-regulated and positively correlated with KM dose. KM had a growth-promoting effect that was related to cell proliferation driven by the TGF-β1/Smad, MAPK, and Jak/Stat signaling pathways. KM at 0.2 mg/kg optimized the growth performance of C. carpio, while higher concentrations of KM (2 and 20 mg/kg) may induce apoptosis without significantly damaging the fish intestinal structure. Therefore, KM at low concentration has great potential for development as an aquatic growth promotion additive.

Effect of Humantenine on mRNA m6A Modification and Expression in Human Colon Cancer Cell Line HCT116

Humantenine, an alkaloid isolated from the medicinal herb Gelsemium elegans (Gardner & Chapm.) Benth., has been reported to induce intestinal irritation, but the underlying toxicological mechanisms remain unclear. The object of the present study was to investigate the RNA N6-methyladenosine (m6A) modification and distinct mRNA transcriptome profiles in humantenine-treated HCT116 human colon cancer cells. High-throughput MeRIP-seq and mRNA-seq were performed, and bioinformatic analysis was performed to reveal the role of abnormal RNA m6A modification and mRNA expression in humantenine-induced intestinal cell toxicity. After humantenine treatment of HCT116 cells, 1401 genes were in the overlap of differentially m6A-modified mRNA and differentially expressed mRNA. The Kyoto Encyclopedia of Genes and Genomes and Gene Ontology annotation terms for actin cytoskeleton, tight junctions, and adherens junctions were enriched. A total of 11 kinds of RNA m6A methylation regulators were differentially expressed. The m6A methylation levels of target genes were disordered in the humantenine group. In conclusion, this study suggested that the HCT116 cell injury induced by humantenine was associated with the abnormal mRNA expression of m6A regulators, as well as disordered m6A methylation levels of target genes.

Molecular Mechanism of Gelsemium elegans (Gardner and Champ.) Benth. Against Neuropathic Pain Based on Network Pharmacology and Experimental Evidence

Gelsemium elegans (Gardner and Champ.) Benth. (Gelsemiaceae) (GEB) is a toxic plant indigenous to Southeast Asia especially China, and has long been used as Chinese folk medicine for the treatment of various types of pain, including neuropathic pain (NPP). Nevertheless, limited data are available on the understanding of the interactions between ingredients-targets-pathways. The present study integrated network pharmacology and experimental evidence to decipher molecular mechanisms of GEB against NPP. The candidate ingredients of GEB were collected from the published literature and online databases. Potentially active targets of GEB were predicted using the SwissTargetPrediction database. NPP-associated targets were retrieved from GeneCards, Therapeutic Target database, and DrugBank. Then the protein-protein interaction network was constructed. The DAVID database was applied to Gene Ontology and Kyoto Encyclopedia of Genes and Genome pathway enrichment analysis. Molecular docking was employed to validate the interaction between ingredients and targets. Subsequently, a 50 ns molecular dynamics simulation was performed to analyze the conformational stability of the protein-ligand complex. Furthermore, the potential anti-NPP mechanisms of GEB were evaluated in the rat chronic constriction injury model. A total of 47 alkaloids and 52 core targets were successfully identified for GEB in the treatment of NPP. Functional enrichment analysis showed that GEB was mainly involved in phosphorylation reactions and nitric oxide synthesis processes. It also participated in 73 pathways in the pathogenesis of NPP, including the neuroactive ligand-receptor interaction signaling pathway, calcium signaling pathway, and MAPK signaling pathway. Interestingly, 11-Hydroxyrankinidin well matched the active pockets of crucial targets, such as EGFR, JAK1, and AKT1. The 11-hydroxyrankinidin-EGFR complex was stable throughout the entire molecular dynamics simulation. Besides, the expression of EGFR and JAK1 could be regulated by koumine to achieve the anti-NPP action. These findings revealed the complex network relationship of GEB in the "multi-ingredient, multi-target, multi-pathway" mode, and explained the synergistic regulatory effect of each complex ingredient of GEB based on the holistic view of traditional Chinese medicine. The present study would provide a scientific approach and strategy for further studies of GEB in the treatment of NPP in the future.