Chronic inflammatory disorders like neuroinflammatory disorders and ulcerative colitis (UC) have some common pathogenic mechanisms such as persistent activation of nuclear factor-κB (NF-κB), oxidative and nitrosative stress, mitochondrial dysfunction, immune dysregulation, and disruption of the integrity of the epithelial barrier. The gut-brain-immune axis is a bidirectional communication pathway, with growing evidence that intestinal inflammation impairs central neuroimmune responses and vice versa, underscoring the importance of therapeutic interventions that can address and impact these interconnected axes. Harmaline or β-carboline alkaloid, a naturally occurring compound mainly found in Peganum harmala and Banisteriopsis caapi, has gradually gained a lot of interest due to its wide range of pharmacological properties such as anti-inflammatory, antioxidant, neuroprotective, and immunomodulatory. The review focuses on the reported modulation of the major inflammatory pathways, such as inhibition of NF-κB signalling, attenuation of pro-inflammatory cytokine production, regulation of oxidative stress through the Nrf2-dependent pathway, and reversible inhibition of monoamine oxidase-A (MAO-A), by critically evaluating the inflammopharmacological profile of harmaline. All of these molecular activities indicate that harmaline could affect biological activities related to neuroinflammation, intestinal inflammation, and gut-brain-immune communications. Nevertheless, there is limited direct experimental evidence supporting the efficacy of harmaline in disease-specific models of ulcerative colitis, neuroinflammation, and microbiota-associated diseases. Hence, the indicated therapeutic relevance of harmaline has to be considered as hypothesis-generating and mechanistically plausible but for now not experimentally proven in disease-specific contexts. In general, harmaline is a promising mechanistic lead compound to be investigated in future complex inflammatory diseases which involve brain/gut and neuroimmune interactions. Additional research regarding disease-specific efficacy, pharmacokinetic properties, tissue distribution, microbiota-related aspects, dose-response, and safety aspects is needed to evaluate its translatability.

The remediation of heavy metal contamination in agricultural soils requires sustainable, eco-friendly agronomic interventions. This study reports the application of pre-synthesized and thoroughly pre-characterized silver (Ag), copper (Cu), and Ag-Cu bimetallic nanoparticles (NPs) originally fabricated via a Peganum harmala-mediated green synthesis pathway. We investigate these pre-characterized NPs as nano-chemical regulators to mitigate nickel (Ni) toxicity in wheat (Triticum aestivum L.), focusing on the relationship between nanoparticle composition (monometallic vs. bimetallic) and the modulation of the plant's chemical defense and metal translocation pathways. While the baseline structural baseline, including crystalline properties, chemical capping, and size distribution (20-30 nm), was established in our prior work via UV-Vis, XRD, FTIR, SEM/TEM, and DLS analyses, the current investigation focuses entirely on evaluating their downstream agronomic efficacy. Application of 250 mg L[-1] NPs via seed priming and foliar spray under 100 mg kg[-1] Ni stress significantly altered the plant's biochemical profile. Cu-NPs provided the most robust growth response, increasing grain yield by 21.3% in the Borlaug-16 cultivar. Chemically, the Ag-Cu bimetallic system demonstrated superior antioxidant stimulation, enhancing total phenolic and anthocyanin contents by 112.82% and 116.86%, respectively. This was accompanied by a synergistic enhancement of SOD (90.7%) and POD (122%) enzymatic activities, which led to an 82.7% reduction in H2O2 oxidative markers. Crucially, ionomic analysis revealed that Ag-Cu NPs act as chemical facilitators for Ni mobility, increasing the translocation factor from roots to grains (TF up to 4.2). These findings demonstrate that repurposing these green-synthesized nanoparticles effectively reprograms the wheat plant's chemical response to heavy metal stress. While the bimetallic Ag-Cu NPs provide superior biochemical protection against oxidative damage, they simultaneously promote the mobilization of Ni into edible tissues. This study highlights a critical chemical trade-off between physiological resilience and toxicological safety, providing essential data for the design of "smart" nano-agrochemicals that balance crop productivity with food safety requirements.

Pollinator health depends critically on gut microbiome composition, yet species-specific responses to agricultural environments remain unclear. We compared gut microbiome dynamics and dietary shifts in Osmia excavata, Megachile rotundata, and Apis cerana during alfalfa pollination using 16S rRNA sequencing and rbcL metabarcoding. Alpha diversity revealed distinct patterns: O. excavata showed reduced richness but increased evenness after foraging, M. rotundata exhibited reduced diversity, while A. cerana remained stable. Beta diversity demonstrated microbiome convergence among species after release, indicating environmental filtering. Dietary analysis revealed polylectic foraging dominated by Citrullus lanatus, Peganum nigellastrum, and Zea mays, with minimal alfalfa consumption. Pseudomonadota and Bacillota predominated, with species-specific signatures: Gilliamella in A. cerana, Lactobacillus in M. rotundata, and Bacillus in O. excavata. These findings demonstrate that microbiome assembly reflects host sociality-environment interactions, with solitary bees showing greater plasticity. This study provides a microbial foundation for pollinator conservation in agricultural systems.

Peganum harmala L. is a plant rich in β-carboline alkaloids, especially harmine, which is widely used in folk medicine and has therapeutic and toxic effects depending on the dose. In order to determine the toxic properties of harmine, the experiment was carried out by perorally treating this substance to the animals at a dose of 20 mg/kg every day for 14 days. As a result, although the absolute liver weight was significantly increased in the harmine-treated group compared to the control rats (4.65 g vs. 4.25 g, p = 0.04), the relative liver weight was significantly decreased (2.96% vs. 3.55%, p = 0.0045), likely reflecting the disproportionate increase in total body mass observed in the harmine group (157.25 g vs. 119.5 g, p = 0.0002). Additionally, the relative weight of the cerebral hemispheres was significantly reduced, and a statistically significant increase in ALT levels was observed. In the rats treated with harmine, blood was observed in the urine in 85.72% on the first day, and nitrites and proteins were observed in 71.3%. Examination of the amounts of alkaloids in organs and samples, very high amounts of harmine were found, especially in the liver. The 97.78% decrease in harmine content when passing from the stomach to the small intestine indicates its absorption from the stomach. As the result of light and transmission electron microscopy pathological changes were detected due to harmine such as damage to the wall of the central venous vessels and sinusoids, increase in the amount of edema fluid as a result of increased vascular permeability, indistinguishability of boundaries between hepatocytes and steatosis in their cytoplasm, vacuolization, increase in the amount of lysosomes, dystrophy of some nuclei, destruction of the microvilles of bile capillaries.

The present study reports the green synthesis and characterisation of β-cyclodextrin-capped silver nanoparticles (β-CD@AgNPs) using Peganum harmala L. fruit extract as both a reducing and stabilising agent. Multiple spectroscopic and microscopic techniques confirmed the nanoparticles. UV-visible analysis revealed surface plasmon resonance bands at 405 and 549 nm, confirming AgNP formation and β-CD mediated stabilisation. FTIR spectra indicated the involvement of hydroxyl, carbonyl, and glycosidic functional groups in nanoparticle capping, while XRD confirmed crystalline, face-centred cubic AgNPs with additional β-CD peaks. TEM analysis showed well-dispersed spherical nanoparticles sized 4-24 nm, while DLS and zeta potential analyses confirmed colloidal stability (-26.8 mV). The antimicrobial activity of β-CD@AgNPs demonstrated strong inhibitory effects against plant pathogens, including Xanthomonas campestris, Pseudomonas syringae, Bacillus subtilis, and Aspergillus niger in a dose-dependent manner, with low MIC and MBC/MFC values indicating potent bactericidal and fungicidal activity. Insecticidal bioassays against Spodoptera exigua revealed significant concentration- and time-dependent larval mortality, reduced leaf consumption, and strong feeding deterrence. LD50 and LT50 values confirmed enhanced toxicity with prolonged exposure and higher concentrations. The findings highlight that β-CD@AgNPs exhibit dual antimicrobial and larvicidal activities, offering an eco-friendly, sustainable alternative to conventional pesticides and chemical agents. The synergistic role of β-CD enhanced nanoparticle stability, dispersibility, and bioavailability, contributing to prolonged biological efficacy. Thus, β-CD@AgNPs synthesised from P. harmala L. fruit extract hold promise as green nanobiopesticides for integrated crop protection and plant disease management.

β-carboline alkaloids such as harmine and harmaline are prominent specialized metabolites in Peganum multisectum and exert potent inhibitory effects on seedling growth of treated plants, highlighting their potential for development as novel herbicides. However, the enzymatic logic underlying their biosynthesis remains unresolved. Here, we identified two O-methyltransferases, PmOMT1 and PmOMT2, that catalyze the 7-O-methylation of harmol and harmolol, respectively, to form harmine and harmaline. Heterologous expression, biochemical assays, and substrate-feeding experiments in Nicotiana benthamiana confirm their catalytic activities. Intriguingly, phylogenetic analysis and ancestral sequence reconstruction revealed that these enzymes evolved from broadly distributed caffeic acid O-methyltransferases (COMTs). COMT enzymes, which function in S-lignin and melatonin biosynthesis, also have weak β-carboline 7-O-methylation activity and provide a latent foundation for subsequent specialization. Structural modeling and site-directed mutagenesis further revealed key residues and pocket remodeling events that underlie the shift in substrate recognition in PmOMT1 and PmOMT2 relative to canonical COMTs. More importantly, phytotoxicity assays showed that harmine and harmaline exhibit stronger inhibitory effects on Amaranthus tricolor seedling root growth than harmol and harmolol, pointing to possible ecological roles for β-carboline methylation in Peganum. Together, our findings uncover the O-methylation step in β-carboline biosynthesis and illuminate how pre-existing catalytic potential in COMTs can be co-opted to generate lineage-specific alkaloid chemistry in Peganum.

Heavy metal contamination poses a serious threat to agricultural sustainability, particularly in arid regions where soil and crop quality are easily compromised. This study evaluated the potential of indigenous plant growth-promoting rhizobacteria (PGPR) consortia, isolated from Peganum harmala L., to improve wheat (Triticum durum Desf.) growth and bioremediate lead-contaminated soils. Sixteen characterized strains, possessing both PGPR and heavy metal resistance traits were grouped into three consortia (SCA, SCB, and S(CA × CB)) derived from rhizosphere, endosphere, and mixed origins. Each consortium was inoculated separately onto wheat grown in soils containing 800 ppm lead (Pb). Results demonstrated significant improvements across treatments compared to the control: germination rates reached up to 100%; aerial fresh weight, total soluble sugars, phenolics, and flavonoids all increased markedly (up to 78.3, 61.0, 33.1, and 50.6%, respectively). Root system architecture, protein, and sugar contents also showed notable enhancements. These findings highlight the dual function of these indigenous consortia, as agents of both plant growth promotion and efficient bioremediation. Our work provides a practical, ecofriendly framework for restoring heavy metal-affected soils and optimizing crop productivity using tailored microbiological treatments.

This is the first report on the chemical composition, antimicrobial and antioxidant activities of the essential oil of Peganum harmala L. seeds harvested at different maturation stages, i.e. unripe, semi-ripe, and ripe. Essential oils were extracted by hydrodistillation and their chemical composition was determined by GC-MS. 65 compounds were detected. Unripe seeds were characterised by hexadecanoic acid (20.3%) and phytol (13.9%). In semi-ripe seeds, n-pentacosane (23.0%) and hexadecanoic acid (21.8%) predominated, whereas hexahydrofarnesylacetone (33.7%) and 1-eicosanol (11.3%) were the main compounds of ripe seeds. The essential oils exhibited moderate scavenging activity against DPPH radicals, with IC50 values ranging from 0.76 ± 0.01 to 2.72 ± 0.02 mg/mL. Antimicrobial activity was mainly directed against S. aureus ATCC 6816 and C. albicans ATCC 10231, while the efficacy on E. coli ATCC 25922 was limited. Molecular docking studies have identified key components of the essential oil of P. harmala seeds that exhibit significant bioactivity.

Endophytic bacteria from plants adapted to arid and semi-arid environments represent an underexplored reservoir of microbial diversity with potential agricultural applications. Here, we report a polyphasic taxonomic and genome-based characterization of Achromobacter sp. isolates recovered from root and foliar tissues of Citrullus colocynthis and Peganum harmala, two medicinal plants thriving under harsh environmental conditions. Whole-genome sequencing, phylogenomic analyses, average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), multilocus sequence typing, and detailed phenotypic profiling revealed three previously undescribed species, for which we propose the names Achromobacter colocynthi sp. nov., Achromobacter maghribensis sp. nov., and Achromobacter semiaridum sp. nov. Genome assemblies were highly complete (98.7-99.2%) with minimal contamination (<1%), supporting robust taxonomic inference. All three species displayed ANI and dDDH values below accepted thresholds relative to their closest phylogenetic neighbors, despite partial inconsistencies in 16S rRNA similarity for one isolate, highlighting the value of genome-wide metrics for species delineation. Phylogenomic analyses placed the novel taxa within Achromobacter sp. as distinct evolutionary lineages. Phenotypic characterization indicated broad metabolic versatility, including utilization of carbohydrates, organic acids, and amino acids, tolerance to moderate salinity and acidic pH, and resistance to multiple antimicrobial compounds, traits likely linked to adaptation to endophytic lifestyles under semi-arid conditions. Beyond their taxonomic novelty, the isolates exhibited in vitro traits associated with plant adaptation and stress tolerance, including IAA production, ACC deaminase activity, and tolerance to Zn, Cu, and Cd. Genomic analyses further indicated functions related to phosphate acquisition and stress response. These findings expand the taxonomic framework of Achromobacter sp., establish C. colocynthis and P. harmala as reservoirs of novel endophytic bacteria, and highlight their potential relevance for agricultural biotechnology in stress-prone environments.

Phytochemical investigation of the roots of Peganum harmala resulted in the isolation and characterization of 10 alkaloids, including three new ones (1, 2b, and 3) and seven known ones (2a, 4 - 6, 7a/7b, and 8). Their structures were elucidated by spectroscopic data and quantum mechanical calculations, revealing that these compounds primarily consist of quinazoline-type alkaloids, with one pteridine analogue (4) also identified. Especially, 1 was the first 2-hydroxyl vasicine-type quinazoline, 2b and 3 were two new enantiomers, and 4 was identified for the first time in the genus Peganum. Selected isolates (6 - 8) exhibited pronounced selectivity against the A549 cell line.

Members of the genus Rhizobium are best known for nitrogen-fixing symbioses with legumes, yet their diversity and evolutionary roles in non-legume hosts remain poorly explored, particularly in arid ecosystems. We report the isolation and characterization of strain AGC32, an endophytic bacterium obtained from surface-sterilized roots of the desert medicinal plant Peganum harmala collected in Moroccan drylands. Phylogenomic analyses placed AGC32 within the genus Rhizobium but clearly distinct from described species, with average nucleotide identity values below 96% and digital DNA-DNA hybridization values below 70%, supporting its designation as a novel species for which the name Rhizobium moroccans sp. nov. is proposed. Comparative genomics revealed extensive structural genome rearrangements relative to its closest sequenced relative, Rhizobium deserti, indicating a divergent evolutionary trajectory. The high-quality draft genome encodes metabolic pathways associated with adaptation to nutrient limitation and environmental stress, including complete allantoin utilization, polyphosphate metabolism, organic acid assimilation, and multiple systems involved in oxidative and osmotic stress tolerance. Phenotypic assays corroborated these genomic predictions, demonstrating the ability to metabolize diverse organic acids and carbohydrates and to express multiple plant growth-promoting traits, including nitrogen fixation and the solubilization of phosphorus, potassium, and silicon. Collectively, these findings expand the ecological and evolutionary diversity of Rhizobium, demonstrate its capacity to associate with non-legume medicinal plants in extreme environments, and highlight desert ecosystems as reservoirs of previously unrecognized microbial diversity with potential applications in sustainable agriculture in arid regions.