Isoquinoline Alkaloids Research Articles

Palmatine ameliorates cisplatin-induced acute kidney injury through regulating Akt and NF-κB/MAPK pathways

Cisplatin-induced acute kidney injury (CIAKI) is a major dose-limiting toxicity of cisplatin treatment. The mechanisms of CIAKI involve the production of inflammation, apoptosis and oxidative stress. Palmatine, an isoquinoline alkaloid has anti-inflammatory activity. Here, we investigated the protective effect and underlying mechanism of palmatine on CIAKI by in vitro and in vivo experiments based on network pharmacology. Network pharmacology was used to analyze the relationship and potential mechanisms of palmatine and CIAKI. The protective effect of palmatine was validated in cisplatin induced 293 T cell injury model and mice model. Furthermore, the mechanism of palmatine on CIAKI was determined by detecting inflammatory factors and related signaling pathways. A total of 61 targets of palmatine against CIAKI and the closely related signaling pathways including oxidative stress, MAPK and Akt were found. Palmatine effectively protected 293 T cells and mouse kidney against CIAKI. Mechanistically, palmatine reduced CIAKI inflammation by suppressing the NF-κB/MAPK pathway. Meanwhile, palmatine inhibited apoptosis by activating the Akt pathway and reduced oxidative stress. The results of in vitro and in vivo experiments were consistent with those of network pharmacology. Furthermore, the cytotoxicity of cisplatin to H460 and HCT116 cells was slightly improved by palmatine. In conclusion, palmatine protects against CIAKI by inhibiting inflammation and apoptosis through regulation of NF-κB/MAPK and Akt pathways. Palmatine is a potential adjunctive treatment during the use of cisplatin.

Variability of Isoquinoline Alkaloid Profiles and Anticholinesterase Activities with Binding-Mode Predictions of Glaucium flavum Population.

In this study, phytochemical and biological activity studies supported by docking were carried out on a species of the genus Glaucium, a repository of isoquinoline alkaloids. The GC-MS (Gas Chromatography-Mass Spectrometry) method is used to characterize the isoquinoline alkaloids of Glaucium flavum Crantz. (Papaveraceae). G. flavum was collected from seven different regions of Türkiye (Antalya, Urla-Izmir, Mordogan-Izmir, Mugla, Assos-Canakkale, Karabiga-Canakkale, Giresun) and totally 17 compounds were detected by GC-MS. Glaucine was found to be the major constituent in the sample collected from Mugla, whereas isocorydine was recorded to be the principal alkaloid in other samples. Further fractionation studies on G. flavum collected from Antalya province in Southwestern Türkiye, yielded five major alkaloids (isocorydine 1, dihydrosanguinarine 2, glaucine 3, dehydroglaucine 4, protopine 5) which were characterized by spectroscopic methods. Anticholinesterase activities of the extracts and isolated alkaloids were also tested by in vitro Ellman method. The isolated compounds were also analyzed by a molecular docking technique to determine the binding orientations in the gorge of the active site of acetylcholinesterase (AChE) and a homology model of butyrylcholinesterase (BuChE). This is the first comparative investigation of the phytochemical composition and biodiversity of Glaucium flavum species growing in Türkiye.

Effects of a dietary isoquinoline alkaloids blend on gut antioxidant capacity and gut barrier of young broilers

Extensive mechanistic evidence to support the beneficial function of dietary phytobiotic applications for broiler performance, gut function and health is highly warranted. In particular, for isoquinoline alkaloids (IQ) the underlying mechanisms related to critical gut homeostasis components such as cytoprotection and gut barrier are scarce, especially for young broilers at the starter growth stage (d1-10). The aim of this study was to investigate the effect of a standardized blend of IQs on the relative gene expression of critical biomarkers relevant for antioxidant response and barrier function along the intestine of young broilers at the end of starter growth phase. For this purpose, 182 one-day-old Ross 308 broilers were allocated in 2 treatments with 7 replicates of 13 broilers each: control diet-no other additions (NC), and control diet containing a standardized blend of IQs at 200 mg/kg of diet (M) for the starter growth period (1-10d). The results revealed that the IQs blend significantly upregulated (P < 0.05) the expression of genes related to antioxidant response in all intestinal segments. Moreover, the IQs blend enhanced (P < 0.05) gut barrier components primarily at duodenal level. In conclusion, the blend of IQs beneficially affected critical pathway components relevant for the gut antioxidant capacity and barrier along the intestine of young broilers.

Untargeted metabolomic analysis of the metabolites in roots of Pugionium cornutum seedlings under drought stress.

Pugionium cornutum is an annual or biennial xerophyte distributed in arid regions, with drought resistance properties. While previous studies have predominantly focused on the physiological changes of P. cornutum , the understanding of its metabolite variations remains limited. In this study, untargeted metabolomic technology was performed to analyse the change of metabolites in the roots of P. cornutum seedlings under drought stress. Our findings revealed that compared to the R1, the root water potential and the number of lateral roots increased, while the length of the tap root and fresh weight increased first and then decreased. In the R1-R2, a total of 45 differential metabolites (DMs) were identified, whereas in the R1-R3 82 DMs were observed. Subsequently, KEGG analysis revealed a significant enrichment of microbial metabolism in diverse environments and aminobenzoate degradation in the R1-R2, and phenylpropanoid biosynthesis, ubiquinone, and other terpenoid-quinone biosynthesis and isoquinoline alkaloid biosynthesis were significantly enriched in the R1-R3. The upregulation DMs, including L-arginosuccinate, L-tyrosine, p-coumarate, caffeate, ferulate, vanillin, coniferin, 5-aminopentanoate, 2-methylmaleate and 2-furoate in P. cornutum seedlings may play a crucial role in enhancing root growth and improving drought resistance. These findings provide a basis for future investigations into the underlying mechanisms of drought resistance in P. cornutum .

Modulating cecal microbiome and in silico amino acid metabolism of sanguinarine-based isoquinoline alkaloids supplements in natural heat stress broiler

Broilers reared under tropical conditions are exposed to Heat Stress (HS) yielding adverseness in production. The study aimed to evaluate the effect of plant-derived sanguinarine-based Isoquinoline alkaloids (IQ) on integrating performance of growth with the cecal microbiome and functional metabolism profiles of amino acid metabolism for either precision nutrition or productivity promotion using nutrition strategies with intestinal microecological balance in broilers of 14-and 35-day of age under HS conditions. IQ significantly improved performance, body weight, average daily weight gain, feed intake, and mortality. IQ significantly modulated the cecum microbiome (14- and 35-dayo of age) by enriching microbiome diversity with increase in Bacteriodetes and Cyanobacteria, but decrease in Firmicutes and Proteobacteria. It was found on 14-day of age that abundances of Turicibactor sanguinis, Lactobacillus salivarious, Lactobacillus sacidophilus, and Akkermansia municiphila in the cecum of boiler fed with IQ60 were higher than in that of the control group. While abundances of Enteroccucus cecorum, Enteroccuus villorum, Escherichia fergusonii, and Helicobacter pullorum were lower in broiler fed with IQs demonstrating the potential to suppress Antimicrobial-Resistant (AMR) reservoirs in the cecum. IQs significantly increased amino acid metabolism namely, l-arginine degradation VII and l-tryptophan degradation I, l-tryptophan degradation VI on day 14, and l-alanine degradation VII, l-tryptophan biosynthesis, l-methionine biosynthesis I, l-methionine salvage cycle, and l-threonine degradation II on day 35 (Kruskal-Wallis p-value < 0.05) in which positively correlated with BW and FI but negative correlation with FCR (Pearson correlation, P < 0.05). It is the first finding that IQs potentially modulated the crosstalk between host and microbiota via the microbiome-gut-brain axis for gut homeostasis by improving Turicibacter sanguini, that promoted serotonin biosynthesis from colonic Enterochromaffin Cells (EC) in modulating Gastro-Intestinal tract (GI) motility. It can be concluded that IQ exhibited the potential to modulate cecal microbiota to improve functional amino acid pathways supporting growth performance in stress broilers. The phenotypic activity related to genotype prediction under in silico model of functional microbiome systems with multi-Omics methods relating with microbiome community is worthwhile to be further investigated leading to discovering potential phytogenic compounds for precision feed additives in stress broilers.

Berberine modulates cardiovascular diseases as a multitarget-mediated alkaloid with insights into its downstream signals using in silico prospective screening approaches

Atherosclerosis is potentially correlated with several cardiac disorders that are greatly associated with cellular oxidative stress generation, inflammation, endothelial cells dysfunction, and many cardiovascular complications. Berberine is a natural isoquinoline alkaloid compound that widely modulates pathogenesis of atherosclerosis through its different curative potentials. This in silico screening study was designed to confirm the potent restorative properties of berberine chloride as a multitarget-mediated alkaloid against the CVDs and their complications through screening, identifying, visualizing, and evaluating its binding models, affinities, and interactions toward several CVDs-related targets as direct and/or indirect-mediated signals via inhibiting cellular ER stress and apoptotic signals and activating autophagy pathway. The drug-likeness properties of berberine were predicted using the computational QSAR/ADMET and Lipinski’s RO5 analyses as well as in silico molecular docking simulations. The potent berberine-binding modes, residues-interaction patterns, and free energies of binding scores towards several CVDs-related targets were estimated using molecular docking tools. Furthermore, the pharmacokinetic properties and toxicological features of berberine were clearly determined. According to this in silico virtual screening study, berberine chloride could restore cardiac function and improve pathogenic features of atherosclerotic CVDs through alleviating ER stress and apoptotic signals, activating autophagy, improving insulin sensitivity, decreasing hyperglycemia and dyslipidemia, increasing intracellular RCT signaling, attenuating oxidative stress and vascular inflammation, and upregulating cellular antioxidant defenses in many cardiovascular tissues. In this in silico study, berberine chloride greatly modulated several potent CVDs-related targets, including SIGMAR1, GRP78, CASP3, BECN1, PIK3C3, SQSTM1/p62, LC3B, GLUT3, INSR, LDLR, LXRα, PPARγ, IL1β, IFNγ, iNOS, COX-2, MCP-1, IL10, GPx1, and SOD3.

COMPARATIVE CHROMATOGRAPHIC AND SPECTRAL STUDY OF THE ALKALOID COMPOSITION OF THE BIOMASS OF TISSUE CULTURE AND THE HERB OF GLAUCIUM FLAVUM

Introduction. The culture of plant cells and tissues is an effective technology for obtaining various secondary metabolites, including for use in the pharmaceutical industry. Compounds synthesized in callus and suspension cultures may be identical to plant ones, and the yield of secondary metabolites, in some cases, exceeds plant sources. In this regard, yellow hornpoppy (Glaucium flavum Crantz.) is of great interest, containing glaucin, which has a unique antitussive effect and is a source of a number of medications. The purpose of this study is a comparative phytochemical study of the alkaloid composition of the tissue culture and the herb of Glaucium flavum. Material and methods. Callus tissue cultures of yellow hornpoppy yellow hornpoppy (Glaucium flavum Crantz.) were obtained in the laboratory of the Institute of Pharmacy of Kazan State Medical University. The herb of the Glaucium flavum cultivated on the territory of the Botanical Garden of Samara University was collected during the flowering period of plants in 2021. A comparative study of the alkaloid composition of the callus culture and the herb of Glaucium flavum was carried out by methods of luminescent microscopy on an Altami LUM-2 microscope (Russia), thin-layer chromatography (TLC) on Sorbfil-PTSH-AF-A-UV plates, as well as spectrophotometry. A mixture of solvents n-butanol-acetic acid-water 4:1:2 was used as a solvent system. The detection of separated substances was carried out by scanning chromatographic plates in UV light at a wavelength of 366 and 254 nm, followed by the manifestation of Dragendorf reagent. The identification of the isolated glaucin hydrochloride was carried out on the basis of UV, 1H-NMR, 13C-NMR spectroscopy data. 1H NMR spectra were obtained on the "JNM-ECX 400" device (399.78MHz), 13C NMR spectra were obtained on the "JNM–ECX 400" device (100.52 MHz). The spectra were recorded using a Specord 40 spectrophotometer (Analytik Jena AG, Germany) in the wavelength range of 190-500 nm. Results. During the luminescent analysis of the tissue culture of the Glaucium flavum Crantz., as well as intact plants, the type of luminescence characteristic of isoquinoline alkaloids was noted. Using TLC analysis, isoquinoline alkaloids, including glaucin, were found in samples of callus cultures and the aerial parts of Glaucium flavum, however, a lower glaucin content was noted in the sample of the callus culture compared to that of the intact plant. The spectrophometric analysis of the studied samples showed that the nature of the absorption curve in intact plants and crops of the so-called Glaucium flavum has both common and distinctive features. The UV spectrum of water-alcohol extraction from a sample of Glaucium flavum tissue culture has a similar spectrophotometric profile, however, it contains only one absorption maximum (288 nm), coinciding with that of the UV spectrum of water-alcohol extraction from the herb of this plant. Conclusions. Therefore, the final conclusion regarding the content of glaucin in the studied samples can be made only during the preparative isolation of substances from the biomass of Glaucium flavum using column chromatography

Determination of Ketamine and Palmatine in Rat Plasma by UHPLC-MS/MS and their Pharmacokinetic Interaction

Objective:: Ketamine, commonly known as “K-powder,” is increasingly being abused as a “prom drug.” Palmatine, a typical isoquinoline alkaloid, is mainly found in the roots and stems of natural Chinese herbal medicine plants such as Phellodendron chinense, Coptis chinensis, Sankezhen and Nantianzhu. Herein, we aim to establish a UHPLC-MS/MS method to determine ketamine and palmatine concentrations in rat plasma and investigate the pharmacokinetic interaction of ketamine and palmatine. Methods:: Three groups of eighteen rats each were assigned to ketamine, palmatine, ketamine and palmatine. The pharmacokinetic interaction between ketamine and palmatine was demonstrated using UHPLC-MS/MS. Results:: When ketamine was combined with palmatine, the mean residence time (MRT) was significantly different from that of the ketamine group. MRT decreased after combined use. The interaction showed that palmatine can influence the mean residence time of ketamine; no significant differences were observed for other pharmacokinetic parameters between the ketamine or palmatine group and the ketamine-palmatine group. Conclusion:: Palmatine may influence the mean residence time of ketamine.

Sinomenine: A Protential Biomaterial for Its Antitumor Effect in H22 Hepatoma-Bearing Mice and Its Mechanisms

Sinomenine (SIN) is a natural isoquinoline alkaloid extracted from the Chinese medicinal plant Sinomenium acutum with promising antitumor properties. Although its antitumor effect and mechanism have been studied, its effects on the structure and function of tumor cell membranes remain unclear. This study aimed to evaluate the antitumor effect of SIN on H22 hepatoma-bearing mice and its mechanism of action on tumor cell membranes, and the tumor inhibition rate and life extension rate were examined. Flow cytometry was used to evaluate the dose-dependent induction of apoptosis in H22 cells. The main components of tumor cell membrane, including total protein, cholesterol and sialic acid (SA) were characterized. The ultrastructure of cell membrane was observed using transmission electron microscopy (TEM). Furthermore, SIN’s effect on the function of cell membranes was studied by analyzing fluidity, sealing, and ion pump activity. The results demonstrated that SIN effectively inhibited the growth of liver cancer cells in vivo and prolonged the lifespan of H22 hepatoma-bearing mice. SIN induced apoptosis of H22 cells in a dose-dependent manner, significantly reduced total protein, cholesterol, and SA contents in H22 cell membranes, and significantly decreased the fluidity, sealing, Na+/K+-ATPase and Ca2+/Mg2+-ATPase activities of H22 cell membranes with increasing doses. Overall, these findings suggested that SIN reduced the main component contents of H22 cell membranes, leading to changes in structure and function of cell membrane, ultimately resulting in tumor cell apoptosis and inhibition of tumor growth. The findings indicated that SIN has great potential as a biomaterial for anti-liver cancer drugs, and provides new ideas and methods for developing antitumor drugs through membrane pharmacology.

LC-MS-Based Metabolomics Reveals the Mechanism of Protection of Berberine against Indomethacin-Induced Gastric Injury in Rats.

Berberine is a natural isoquinoline alkaloid with low toxicity, which exists in a wide variety of medicinal plants. Berberine has been demonstrated to exhibit potent prevention of indomethacin-induced gastric injury (GI) but the related mechanism remains unclear. In the present study, liquid chromatography-mass spectrometry (LC-MS)-based metabolomics was applied for the first time to investigate the alteration of serum metabolites in the protection of berberine against indomethacin-induced gastric injury in rats. Subsequently, bioinformatics was utilized to analyze the potential metabolic pathway of the anti-GI effect of berberine. The pharmacodynamic data indicated that berberine could ameliorate gastric pathological damage, inhibit the level of proinflammatory factors in serum, and increase the level of antioxidant factors in serum. The LC-MS-based metabolomics analysis conducted in this study demonstrated the presence of 57 differential metabolites in the serum of rats with induced GI caused by indomethacin, which was associated with 29 metabolic pathways. Moreover, the study revealed that berberine showed a significant impact on the differential metabolites, with 45 differential metabolites being reported between the model group and the group treated with berberine. The differential metabolites were associated with 24 metabolic pathways, and berberine administration regulated 14 of the 57 differential metabolites, affecting 14 of the 29 metabolic pathways. The primary metabolic pathways affected were glutathione metabolism and arachidonic acid metabolism. Based on the results, it can be concluded that berberine has a gastroprotective effect on the GI. This study is particularly significant since it is the first to elucidate the mechanism of berberine's action on GI. The results suggest that berberine's action may be related to energy metabolism, oxidative stress, and inflammation regulation. These findings may pave the way for the development of new therapeutic interventions for the prevention and management of NSAID-induced GI disorders.

In Vitro and In Silico of Cholinesterases Inhibition and In Vitro and In Vivo Anti-Melanoma Activity Investigations of Extracts Obtained from Selected Berberis Species.

Berberis species have a long history of use in traditional Chinese medicine, Ayurvedic medicine, and Western herbal medicine. The aim of this study was the quantification of the main isoquinoline alkaloids in extracts obtained from various Berberis species by HPLC, in vitro and in silico determination of anti-cholinesterase activity, and in vitro and in vivo investigations of the cytotoxic activity of the investigated plant extracts and alkaloid standards. In particular, Berberis species whose activity had not been previously investigated were selected for the study. In the most investigated Berberis extracts, a high content of berberine and palmatine was determined. Alkaloid standards and most of the investigated plant extracts exhibit significant anti-cholinesterase activity. Molecular docking results confirmed that both alkaloids are more favourable for forming complexes with acetylcholinesterase compared to butyrylcholinesterase. The kinetic results obtained by HPLC-DAD indicated that berberine noncompetitively inhibited acetylcholinesterase, while butyrylcholinesterase was inhibited in a mixed mode. In turn, palmatine exhibited a mixed inhibition of acetylcholinesterase. The cytotoxic activity of berberine and palmatine standards and plant extracts were investigated against the human melanoma cell line (A375). The highest cytotoxicity was determined for extract obtained from Berberis pruinosa cortex. The cytotoxic properties of the extract were also determined in the in vivo investigations using the Danio rerio larvae xenograft model. The obtained results confirmed a significant effect of the Berberis pruinosa cortex extract on the number of cancer cells in a living organism. Our results showed that extracts obtained from Berberis species, especially the Berberis pruinosa cortex extract, can be recommended for further in vivo experiments in order to confirm the possibility of their application in the treatment of neurodegenerative diseases and human melanoma.

Transcriptome analysis reveals the potential mechanism of altering viability, yield, and isoquinoline alkaloids in Coptis chinensis through Cunninghamia lanceolata understory cultivation

The dried rhizomes of Coptis chinensis hold significance in Chinese medicine. Monocropping C. chinensis under the shade of a manmade scaffold, the primary planting mode, poses a threat to the ecological balance. In recent years, the practice of C. chinensis–Cunninghamia lanceolata understory cultivation has gained prevalence in southwest China. However, there is no evidence to suggest that understory cultivation enhances the viability, yield, or isoquinoline alkaloid content of C. chinensis. This study examined the physiological properties, yield indicators, and isoquinoline alkaloid content to investigate variations in C. chinensis in response to understory cultivation. Transcriptome analysis was conducted to elucidate potential mechanisms driving these alterations. The results indicate that understory cultivation significantly enhances the viability, yield, and levels of epiberberine, palmatine, and berberine in C. chinensis while reducing coptisine content. Transcriptomic analyses identified 2062 upregulated and 1853 downregulated genes in the understory cultivation system. Pathways such as “phenylpropanoid biosynthesis,” “zeatin biosynthesis,” “photosynthesis,” “tyrosine metabolism,” “isoquinoline alkaloid biosynthesis,” and “starch and sucrose metabolism” exhibited significant enrichment of differentially expressed genes (DEGs). DEGs involved in these pathways were thoroughly analyzed. INV, BGL-2, BGL-4, SPS-2, AMY-3, Psb B, Psb R, Psb S, Psa D, Psa E, Psa H, Psa O, Pet C, Pet H, deta, and b exhibited significant positive correlations with plant fresh weight, aboveground fresh weight, and underground fresh weight. 6-OMT-2 and COMT1-3 displayed significant positive correlations with coptisine content, but negative correlations with epiberberine, palmatine, and berberine content. ZOG-1, ZOG-3, TAT, PPO, POD-13 and UGT 73C5-1 showed noteworthy positive correlations with berberine content. Conversely, MIFH, POD-4, POD-5, and POD-8 displayed significant positive correlations with epiberberine, palmatine, and berberine content. POD-5, and POD-7 were significantly negatively correlated with coptisine content. Furthermore, gene expression levels determined by qRT–PCR aligned with the transcriptomic sequencing results, confirming the reliability of the transcriptomic findings. The results of this study contribute evidence elucidating potential mechanisms through which C. chinensis responds to understory cultivation.Graphical

Transcriptional alterations of peanut root during interaction with growth-promoting Tsukamurella tyrosinosolvens strain P9.

The plant growth-promoting rhizobacterium Tsukamurella tyrosinosolvens P9 can improve peanut growth. In this study, a co-culture system of strain P9 and peanut was established to analyze the transcriptome of peanut roots interacting with P9 for 24 and 72 h. During the early stage of co-culturing, genes related to mitogen-activated protein kinase (MAPK) and Ca2+ signal transduction, ethylene synthesis, and cell wall pectin degradation were induced, and the up-regulation of phenylpropanoid derivative, flavonoid, and isoflavone synthesis enhanced the defense response of peanut. The enhanced expression of genes associated with photosynthesis and carbon fixation, circadian rhythm regulation, indoleacetic acid (IAA) synthesis, and cytokinin decomposition promoted root growth and development. At the late stage of co-culturing, ethylene synthesis was reduced, whereas Ca2+ signal transduction, isoquinoline alkaloid synthesis, and ascorbate and aldarate metabolism were up-regulated, thereby maintaining root ROS homeostasis. Sugar decomposition and oxidative phosphorylation and nitrogen and fatty acid metabolism were induced, and peanut growth was significantly promoted. Finally, the gene expression of seedlings inoculated with strain P9 exhibited temporal differences. The results of our study, which explored transcriptional alterations of peanut root during interacting with P9, provide a basis for elucidating the growth-promoting mechanism of this bacterial strain in peanut.

Evaluation of iso-quinoline alkaloids by RP-HPLC-PDA in different Berberis species collected from Western Himalayan Region

The genus Berberis has high significance in Indian and other traditional systems of medicine due to the presence of iso-quinoline alkaloids. This study was conducted to record the metabolic variation in eight Berberis spp. collected from the Western Himalayan region. The RP-HPLC-PDA chromatogram separates the markers jatrorrhizine, palmatine and berberine at specific retention time, 11.45, 16.41 and 18.15 min respectively. The method was validated on linearity, precision and recovery indices as per International Conference on Harmonisation (ICH) guidelines. The maximum content of berberine, palmatine and jatrorrhizine was found in Berberis asiatica (1.74% ± 0.032, 1.63% ± 0.028 and 0.264% ± 0.012, respectively) on % dry weight basis. This study will help in phyto-marker-based identification and differentiation of various Berberis species, which can be used as an alternative to the official drug Daruharidra i.e. Berberis aristata.

A comprehensive assessment of palmatine as anticonvulsant agent – In vivo and in silico studies

Previously, we demonstrated that palmatine (PALM) – an isoquinoline alkaloid from Berberis sibrica radix, exerted antiseizure activity in the pentylenetetrazole (PTZ)-induced seizure assay in larval zebrafish. The aim of the present study was to more precisely characterize PALM as a potential anticonvulsant drug candidate. A range of zebrafish and mouse seizure/epilepsy models were applied in the investigation. Immunostaining analysis was conducted to assess the changes in mouse brains, while in silico molecular modelling was performed to determine potential targets for PALM. Accordingly, PALM had anticonvulsant effect in ethyl 2-ketopent-4-enoate (EKP)-induced seizure assay in zebrafish larvae as well as in the 6 Hz-induced psychomotor seizure threshold and timed infusion PTZ tests in mice. The protective effect in the EKP-induced seizure assay was confirmed in the local field potential recordings. PALM did not affect seizures in the gabra1a knockout line of zebrafish larvae. In the scn1Lab-/- zebrafish line, pretreatment with PALM potentiated seizure-like behaviour of larvae. Repetitive treatment with PALM, however, did not reduce development of PTZ-induced seizure activity nor prevent the loss of parvalbumin-interneurons in the hippocampus of the PTZ kindled mice. In silico molecular modelling revealed that the noted anticonvulsant effect of PALM in EKP-induced seizure assay might result from its interactions with glutamic acid decarboxylase and/or via AMPA receptor non-competitive antagonism. Our study has demonstrated the anticonvulsant activity of PALM in some experimental models of seizures, including a model of pharmacoresistant seizures induced by EKP. These results indicate that PALM might be a suitable new drug candidate but the precise mechanism of its anticonvulsant activity has to be determined.

Multitarget anti-parasitic activities of isoquinoline alkaloids isolated from Hippeastrum aulicum (Amaryllidaceae)

BackgroundChagas disease and leishmaniasis affect a significant portion of the Latin American population and still lack efficient treatments. In this context, natural products emerge as promising compounds for developing more effective therapies, aiming to mitigate side effects and drug resistance. Notably, species from the Amaryllidaceae family emerge as potential reservoirs of antiparasitic agents due to the presence of diverse biologically active alkaloids. PurposeTo assess the anti-Trypanosoma cruzi and anti-Leishmania infantum activity of five isolated alkaloids from Hippeastrum aulicum Herb. (Amaryllidaceae) against different life stages of the parasites using in silico and in vitro assays. Furthermore, molecular docking was employed to evaluate the interaction of the most active alkaloids. MethodsFive natural isoquinoline alkaloids isolated in suitable quantities for in vitro testing underwent preliminary in silico analysis to predict their potential efficacy against Trypanosoma cruzi (amastigote and trypomastigote forms) and Leishmania infantum (amastigote and promastigote forms). The in vitro antiparasitic activity and mammalian cytotoxicity were investigated with a subsequent comparison of both analysis (in silico and in vitro) findings. Additionally, this study employed the molecular docking technique, utilizing cruzain (T. cruzi) and sterol 14α-demethylase (CYP51, L. infantum) as crucial biological targets for parasite survival, specifically focusing on compounds that exhibited promising activities against both parasites. ResultsThrough computational techniques, it was identified that the alkaloids haemanthamine (1) and lycorine (8) were the most active against T. cruzi (amastigote and trypomastigote) and L. infantum (amastigote and promastigote), while also revealing unprecedented activity of alkaloid 7‑methoxy-O-methyllycorenine (6). The in vitro analysis confirmed the in silico tests, in which compound 1 presented the best activities against the promastigote and amastigote forms of L. infantum with half-maximal inhibitory concentration (IC50) 0.6 µM and 1.78 µM, respectively. Compound 8 exhibited significant activity against the amastigote form of T. cruzi (IC50 7.70 µM), and compound 6 demonstrated activity against the trypomastigote forms of T. cruzi and amastigote of L. infantum, with IC50 values of 89.55 and 86.12 µM, respectively. Molecular docking analyses indicated that alkaloids 1 and 8 exhibited superior interaction energies compared to the inhibitors. ConclusionThe hitherto unreported potential of compound 6 against T. cruzi trypomastigotes and L. infantum amastigotes is now brought to the forefront. Furthermore, the acquired dataset signifies that the isolated alkaloids 1 and 8 from H. aulicum might serve as prototypes for subsequent structural refinements aimed at the exploration of novel leads against both T. cruzi and L. infantum parasites.

Genome sequencing and functional analysis of a multipurpose medicinal herb Tinospora cordifolia (Giloy).

Tinospora cordifolia (Willd.) Hook.f. & Thomson, also known as Giloy, is among the most important medicinal plants that have numerous therapeutic applications in human health due to the production of a diverse array of secondary metabolites. To gain genomic insights into the medicinal properties of T. cordifolia, the genome sequencing was carried out using 10× Genomics linked read and Nanopore long-read technologies. The draft genome assembly of T. cordifolia was comprised of 1.01 Gbp, which is the genome sequenced from the plant family Menispermaceae. We also performed the genome size estimation for T. cordifolia, which was found to be 1.13 Gbp. The deep sequencing of transcriptome from the leaf tissue was also performed. The genome and transcriptome assemblies were used to construct the gene set, resulting in 17,245 coding gene sequences. Further, the phylogenetic position of T. cordifolia was also positioned as basal eudicot by constructing a genome-wide phylogenetic tree using multiple species. Further, a comprehensive comparative evolutionary analysis of gene families contraction/expansion and multiple signatures of adaptive evolution was performed. The genes involved in benzyl iso-quinoline alkaloid, terpenoid, lignin and flavonoid biosynthesis pathways were found with signatures of adaptive evolution. These evolutionary adaptations in genes provide genomic insights into the presence of diverse medicinal properties of this plant. The genes involved in the common symbiosis signalling pathway associated with endosymbiosis (Arbuscular Mycorrhiza) were found to be adaptively evolved. The genes involved in adventitious root formation, peroxisome biogenesis, biosynthesis of phytohormones, and tolerance against abiotic and biotic stresses were also found to be adaptively evolved in T. cordifolia.

Alkaloids and phenolic constituents from Glaucium corniculatum

The aerial parts of Glaucium corniculatum were phytochemically investigated. Consequently, 14 compounds, including six alkaloids (1–6) namely dehydroberberine (1), berberine (2), protpine (3), allocryptopine (4), (+)-corydine (5) and glaucine (6); six flavonoids (7–12) including quercetin (7), isorhamnetin (8), rutin (9), isorhamnetin 3-O-rutinoside (narcissoside, narcissin) (10), quercetin-3-O-glucoside-7-O-rutinoside (11), and isorhamnetin 3-O-glucoside-7-O-rutinoside (12); and hydroxycinnamic acid malate esters, (+)-phaselic acid ((+)-2-O-caffeoyl-L-malate) (13), and (+)-2-O-feruloyl-L-malate (14) were identified. Notably, the protoberberine-type isoquinoline alkaloid dehydroberberine (1) was naturally isolated for the first time, and the two flavonoids triosides (11 and 12) were identified for the first time from genus Glaucium and family Papaveraceae. Their structures were assigned through 1D, 2D NMR, HR-ESI-MS experiments, and by comparing the obtained data with those reported in the literature. The identified metabolites in G. corniculatum have important chemotaxonomic implications, suggesting that the biosynthesis of isoquinoline alkaloids is influenced by the plant's geographical location and could serve as valuable chemotaxonomic markers for identifying the plant sources. Furthermore, flavonoids and phenolic acids can be utilized to differentiate between subfamilies within the family Papaveraceae or to distinguish it from closely related families.

Neopetrotaurines A-C, Isoquinoline Alkaloids with an Unprecedented Taurine Bridge from the Sponge Neopetrosia sp.

Neopetrotaurines A-C (1-3), unusual alkaloids possessing two isoquinoline-derived moieties that are linked via a unique taurine bridge, were isolated from a Neopetrosia sp. marine sponge. These new compounds have proton-deficient structural scaffolds that are difficult to unambiguously assign using only conventional 2- and 3-bond 1H-13C and 1H-15N heteronuclear correlation data. Thus, the application of LR-HSQMBC and HMBC NMR experiments optimized to detect 4- and 5-bond long-range 1H-13C heteronuclear correlations facilitated the structure elucidation of these unusual taurine-bridged marine metabolites. Neopetrotaurines A-C (1-3) showed significant inhibition of transcription driven by the oncogenic fusion protein PAX3-FOXO1, which is associated with alveolar rhabdomyosarcoma, and cytotoxic activity against PAX3-FOXO1-positive cell lines.

Protopine protects chondrocytes from undergoing ferroptosis by activating Nrf2 pathway

Osteoarthritis is a highly prevalent joint disease; however, effective treatments are lacking. Protopine (PTP) is an isoquinoline alkaloid with potent anti-inflammatory and antioxidant properties; however, it has not been studied in osteoarthritis. This study aimed to investigate whether PTP can effectively protect chondrocytes from ferroptosis. Primary mouse chondrocytes were treated with tert-butyl hydroperoxide (TBHP) to simulate oxidative stress in an in vitro model of osteoarthritis. Two concentrations of PTP (10 and 20 μg/mL) were validated for in vitro experiments. Cellular inflammation and metabolism were detected using RT-qPCR and western blotting (WB). Ferroptosis was assessed via WB, qPCR, reactive oxygen species (ROS) levels, lipid ROS, and immunofluorescence staining. In vitro, PTP significantly ameliorated chondrocyte inflammation and cytolytic metabolism and significantly suppressed chondrocyte ferroptosis through the activation of the Nrf2 pathway. The anterior cruciate ligament transection (ACLT) mouse model was used to validate the in vivo effects of PTP. The joint cartilage was assessed using the Osteoarthritis Research Society International (OARSI) score, Safranin O staining, and immunohistochemistry. The intra-articular administration of PTP alleviated cartilage inflammation and ferroptosis, as evidenced by the expression of MMP3, MMP13, COL2A1, GPX4, and Nrf2. Overall, we find that PTP exerted anti-ferroptosis and anti-inflammatory effects on chondrocytes to protect the articular cartilage.