Variation of alkaloid contents and antimicrobial activities of Papaver rhoeas L. growing in Turkey and northern Cyprus

Chemical characterization, anti-struvite crystal, anti-inflammatory, analgesic, and antidepressant activities of Papaver rhoeas L. root and leaf extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Papaver rhoeas L. (P. rhoeas) is used to treat a wide range of pathologies. But there is no data on the anti-struvite, anti-inflammatory, analgesic, and anti-depressant effects of root and leaf extracts from this medicinal plant.

AIM OF THE STUDY

This study aimed to chemically characterize and determine the antidepressant, analgesic, anti-inflammatory, and anti-struvite activities of the root extract (RE) and leaf extract (LE) of P. rhoeas, a wild plant.

MATERIALS AND METHODS

The extraction of secondary metabolites and phytochemical screening were carried out using standard methods. The anti-struvite effect of our samples was assessed by Fourier transform infrared spectroscopy (FT-IR) and microscopic observation. For the anti-inflammatory impact, we used the carrageenan-induced paw edema technique in rats. To assess the analgesic effect of the extracts, we recorded the resulting abdominal contraction after intraperitoneal (IP) acetic acid injection. Finally, we assessed the antidepressant effect by conducting the Forced Swimming Test (FST).

RESULTS

Phytochemical screening results revealed the presence of phenols, flavonoids, saponins, tannins, coumarins, terpenoids, and alkaloids. Extraction results confirmed that our extracts were rich in secondary metabolites. Both P. rhoeas extracts limited struvite crystal development by reducing the size and number of crystals, as indicated by FT-IR analysis and microscopic observation. Additionally, the anti-struvite effects of the LE sample were greater than those of the RE sample. The results of the anti-inflammatory capacity of our extracts demonstrate the maximum inhibition of carrageenan-induced edema following 6 h (T6) of injection, ranging from 72.73 ± 7.7% for LE (400 mg/kg) to 95.45 ± 6.42% for the RE sample (400 mg/kg). On the other hand, the results for analgesic activity showed that the number of abdominal contractions in rats treated with RE and LE ranged from 11 ± 1.73 for RE (400 mg/kg) to 18 ± 1.50 for LE (200 mg/kg), while that of aspirin was 10.33 ± 0.57. Furthermore, the FST results show that the immobility time in rats treated with RE and LE varied from 91.98 ± 4.24 s for LE-treated rats (300 mg/kg) to 123.54 ± 7.83 s for RE-treated rats (150 mg/kg).

CONCLUSION

Based on these results, the roots and leaves of the studied plant can be considered a significant source of biologically active molecules for use in the pharmaceutical industry.

Modeling of Sensory Properties of Poppy Sherbet by Turkish Consumers and Changes in Quality Properties during Storage Process

Poppy is an important edible plant containing bioactive components. This study aimed to produce good-tasting poppy sherbet by determining the content using a response surface methodology (RSM). At the same time, bioactive components, phenolic compounds, and color properties were investigated in optimum poppy sherbet during storage; 0.26 g of dried corn poppy flowers, 0.15 g of citric acid, and 4.29 g of sucrose values were the most promising, achieving high scores for color, smell, taste, and general acceptance from sensory properties (sensory score of 8.55 for color; 7.19 for smell; 8.38 for taste; 7.98 for general acceptability). A total of nine polyphenols were detected in the optimum poppy sherbet sample; gallic acid was the most common. There was no statistically significant difference between the samples stored on the 0th and 30th days regarding gallic acid content (23.886 ± 0.164 μg/mL, 23.403 ± 0.343 μg/mL) and protocatechuic acid (1.146 ± 0.048 μg/mL, 1.047 ± 0.038 μg/mL). Total flavonoid contents (TFC), total phenolic contents (TPC), CUPRAC (cupric ion reducing antioxidant capacity), DPPH (e free radical diphenylpicrylhydrazyl), total monomeric anthocyanin (TAC), and color values were found to decrease as the storage period increased. It was considered that a highly palatable and rich bioactive component product could be obtained.

Papaver rhoeas L. stem and flower extracts: Anti-struvite, anti-inflammatory, analgesic, and antidepressant activities

The Papaver rhoeas L. (P. rhoeas) plant, which belongs to the Papaveraceae family, is also used as food and is exploited to treat several health problems. The purpose of this research is to determine the anti-struvite, anti-inflammatory, analgesic, and antidepressant effects of the stem extract (SE) and flower extract (FE) of the plant P. rhoeas. We used polarizing microscopy and Fourier transform infrared spectrometry (FT-IR) to evaluate the anti-struvite effect of our plant. The edema approach induced by the carrageenan molecule was used to study the anti-inflammatory impact of our extracts. The analgesic test was determined by calculating the number of abdominal contractions induced by the intraperitoneal (IP) administration of acetic acid. To evaluate the antidepressant effect of our extracts, we used the forced swimming test (FST). According to the results of the secondary metabolite extraction, both extracts contained high contents of secondary metabolites, while the results of the screening test showed that flavonoids, alkaloids, phenols, tannins, coumarins, saponins, and terpenoids were present. The result of struvite crystallization inhibition observed by polarizing microscopy and FT-IR shows the inhibition of struvite crystal aggregation by SE by decreasing the amount and size of crystals in a manner similar to cystone. The results of anti-inflammatory activity show maximum inhibition of edema after six hours of carrageenan injection in rats (T₆) for all extracts, with a maximum value of 86.36% for SE at the dose of 200 mg/kg. Regarding the analgesic effect of our plant, the lowest number of abdominal contractions was observed in rats treated with SE at a dose of 400 mg/kg. The FST results show that the lowest immobilization time was observed in rats treated with FE at a dose of 400 mg/kg. The results obtained show that the flowers and stems of P. rhoeas can constitute a rich source of bioactive molecules with potential pharmaceutical applications.

Bioactivity of plants eaten by wild birds against laboratory models of parasites and pathogens

Plants are not only used as energy and nutrient resources for herbivores. Plants can be ingested because of their activity against host parasites and other pathogens. This so-called medicinal role of plants is well reported in ethnopharmacology and under-reported in wild animals. More studies on wild animals are needed because any plant in the world contains bioactive compounds, and probably all plants, no matter how toxic they are, experience herbivory. For example, we tested the activity of extracts and essential oils from Papaver rhoeas and Echium plantagineum against a selection of laboratory pathogens because Great bustards Otis tarda preferred these plants during the mating season, with male fecal droppings showing a higher frequency of P. rhoeas particles than the fecal droppings of females. We hypothesized that P. rhoeas could be helpful for males in the mating season if any part of this plant harbors bioactivity against parasites and other pathogens. Males’ immune system is weakened during the mating season because of their investment in secondary sexual characters and sexual display. As a first exploration of the bioactivity of these plants, we evaluated extracts of both plants against a sample of laboratory models, including a flagellated protozoon (Trichomonas gallinae), a nematode (Meloidogyne javanica) and a fungus (Aspergillus niger). Non-polar and polar extracts of the aerial parts of P. rhoeas, especially the extracts of flowers and capsules, and the extracts of leaves and flowers of E. plantagineum showed activity against nematodes and trichomonads. The bioactivity of plants against parasites could explain the foraging behavior of stressed animals. The chemical communication underpinning the capacity of fauna to recognize those plants is far less known.

Ethnopharmacological study of medicinal plants in Kastamonu province (Türkiye)

This study is aimed at determining some of the plants traditionally used in the treatment of diseases by the local people living in Kastamonu province center and surrounding villages. A face-to-face questionnaire was applied and semi-structured interviews were conducted with 52 informants, 34 women and 18 men. Identification of 92 plants belonging to 41 families has been confirmed and their medicinal uses have been recorded. The most used families were Rosaceae (13 taxa), Asteraceae (11), and Lamiaceae (11). The most preferred folk recipes of medicinal plants was decoction (55 taxa) and in preparations and applications, the most used were the leaves (45 taxa). According to the International Classification of Primary Care categories, plants were the most used for digestive disorders (37 taxa), respiratory disorders (27 taxa), and urological disorders (24 taxa). The highest use-value was recorded for Urtica dioica (0.519), and highest relative frequency citation was recorded for Tilia rubra subsp. caucasica (0.231). Male genital diseases had the highest informant consensus factor value (0.83). New areas of use were also determined for Pilosella leucopsilon subsp. pilisquama, Galium palustre, and Astragalus nitens. With this study, new information for folkloric medicines is presented and the usage of herbal drugs in the study area are enhanced.

Papaver Plants: Current Insights on Phytochemical and Nutritional Composition Along with Biotechnological Applications

The genus Papaver is highly esteemed in the pharmacy industry, in the culinary field, and as ornamental plants. These plants are also valued in traditional medicine. Among all Papaver species, Papaver somniferum L. (opium poppy) is the most important species in supplying phytochemicals for the formulation of drugs, mainly alkaloids like morphine, codeine, rhoeadine, thebaine, and papaverine. In addition, Papaver plants present other types of phytochemicals, which altogether are responsible for its biological activities. Therefore, this review covers the phytochemical composition of Papaver plants, including alkaloids, phenolic compounds, and essential oils. The traditional uses are reviewed along with their pharmacological activities. Moreover, safety aspects are reported to provide a deep overview of the pharmacology potential of this genus. An updated search was carried out in databases such as Google Scholar, ScienceDirect, and PubMed to retrieve the information. Overall, this genus is a rich source of alkaloids of different types and also contains interesting phenolic compounds, such as anthocyanins, flavonols, and the characteristic indole derivatives nudicaulins. Among other pharmacological properties, numerous preclinical studies have been published about the analgesic, anticancer, antimicrobial, antioxidant, and antidiabetic activities of Papaver plants. Although it highlights the significant impact of this genus for the treatment of a variety of diseases and conditions, as a future prospect, characterization works accompanying preclinical studies are required along with clinical and toxicology studies to establish a correlation between the scientific and traditional knowledge.

Total Phenolic Content and Antioxidant and Antimicrobial Activities of Papaver rhoeas L. Organ Extracts Growing in Taounate Region, Morocco

The objective of this study is to valorize Papaver rhoeas L. from the Taounate region of Morocco by determining the total polyphenol content (TPC), the total flavonoid content (TFC) and the antioxidant and antimicrobial activities of four organs. The quantification of TPC and TFC in root, stem, leaf and flower extracts (RE, SE, LE and FE, respectively) was estimated by the Folin–Ciocalteu reaction and the aluminum trichloride method, respectively. Two tests were used to assess antioxidant power: the DPPH test and TAC assay. The antimicrobial activity was studied against five pathogenic bacteria and yeast, using two methods: disk diffusion and microdilution. The TPC in LE and LF was twice as high as that in RE and SE (24.24 and 22.10 mg GAE/g, respectively). The TFC values in the four extracts were very close and varied between 4.50 mg QE/g in the FE and 4.38 mg QE/g in the RE. The LE and FE showed low DPPH values with IC50 = 0.50 and 0.52 mg/mL, respectively. The TAC measurement revealed the presence of a significant amount of antioxidants in the studied extracts, mainly in LE and FE (6.60 and 5.53 mg AAE/g, respectively). The antimicrobial activity results revealed significant activity on almost all of the tested strains. The MIC of FE and SE against E. coli 57 was 1.56 and 0.78 mg/mL, respectively, while against the S. aureus it was 50 and 25 mg/mL, respectively. The low MLC value (1.56 mg/mL) was recorded against E. coli 57 by RE and SE.

Ethyl Acetate Fractions of Papaver rhoeas L. and Papaver nudicaule L. Exert Antioxidant and Anti-Inflammatory Activities

Abnormal inflammation and oxidative stress are involved in various diseases. Papaver rhoeas L. possesses various pharmacological activities, and a previously reported analysis of the anti-inflammatory effect of P. nudicaule ethanol extracts and alkaloid profiles of the plants suggest isoquinoline alkaloids as potential pharmacologically active compounds. Here, we investigated anti-inflammatory and antioxidant activities of ethyl acetate (EtOAc) fractions of P. nudicaule and P. rhoeas extracts in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. EtOAc fractions of P. nudicaule and P. rhoeas compared to their ethanol extracts showed less toxicity but more inhibitory activity against LPS-induced nitric oxide production. Moreover, EtOAc fractions lowered the LPS-induced production of proinflammatory molecules and cytokines and inhibited LPS-activated STAT3 and NF-κB, and additionally showed significant free radical scavenging activity and decreased LPS-induced reactive oxygen species and oxidized glutathione. EtOAc fractions of P. nudicaule increased the expression of HO-1, GCLC, NQO-1, and Nrf2 in LPS-stimulated cells and that of P. rhoeas enhanced NQO-1. Furthermore, metabolomic and biochemometric analyses of ethanol extracts and EtOAc fractions indicated that EtOAc fractions of P. nudicaule and P. rhoeas have potent anti-inflammatory and antioxidant activities, further suggesting that alkaloids in EtOAc fractions are potent active molecules of tested plants.

Traditional Herbal Remedies Used for Managing Anxiety and Insomnia in Italy: An Ethnopharmacological Overview

Anxiety and insomnia are among the most common mental health disorders and are a major cause of disability around the world. Traditional herbal medicines are receiving significant attention in global health debates. Several Italian regions maintain rural traditions and are among the most extensively studied areas of Europe regarding medicinal plant uses. The present overview aims to highlight the use of wild and cultivated plants, specifically as sedatives and for insomnia treatment in Italy, and to collect, analyze, and summarize the available literature about their pharmacological activity as well as clinical and pre-clinical studies concerning the most cited plants. In total, 106 wild taxa are used in Italy for sedative purposes. The plant species belong to 76 genera and 32 families, of which the most cited are Asteraceae (24.2%) and Lamiaceae (21.1%). Leaves (29%) and flowers (27%) are the plant parts mostly used as infusion (70%) and decoction (25%). Out of 106 taxa documented, only the most cited are analyzed in this overview (A. arvensis L., C. nepeta L., C. monogyna Jacq., H. lupulus L., L. nobilis L., L. angustifolia Mill., M. sylvestris L., M. chamomilla L., M. officinalis L., O. basilicum L., P. rhoeas L., P. somniferum L., R. officinalis L., T. platyphyllus Scop., and V. officinalis L.). Among the fifteen species selected, only seven have been studied for their pharmacological activity as hypnotic-sedatives. Future pre-clinical and clinical studies are needed to better clarify the mechanism of action of bioactive compounds and confirm the potential of these alternative therapies.

Alkaloid profiling and antimicrobial activities of Papaver glaucum and P. decaisnei

OBJECTIVE

Papaver decaisnei Hochst. & Steud. Ex Elkan and Papaver glaucum Boiss. & Hausskn. growing wild in Northern Iraq have been historically used for medicinal purposes. In this study, both species were evaluated for their alkaloid content and antimicrobial activities.

RESULTS

Alkaloids were extracted and isolated by preparative thin-layer chromatography (TLC). Identification was carried out by comparing spectral data (UV and 1H-NMR) and TLC Rf values with those of authentic samples. Two alkaloids, proapaorphine-type mecambrine and aporphine-type roemerine were isolated from P. decaisnei. Two benzylisoquinoline type alkaloids papaverine (major alkaloid) and palaudine as well as aporphine-type N-methylasimilobine have been obtained in P. glaucum. Both P. glaucum and P. decaisnei extracts revealed strong antimicrobial activity on Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. Collectively these results indicate that P. glaucum and P. decaisnei are promising sources of alkaloids that could further be investigated for medicinal purposes.

Phytomedicine from Middle Eastern Countries: An Alternative Remedy to Modern Medicine against Candida spp Infection

Candida spp are capable of infecting both normal and immunocompromised individuals. More recently, Candida infections have spread considerably in healthcare settings, especially in intensive care units, where it is the most frequently encountered pathogen. Candida albicans is the commonest species encountered, although infections by non-albicans species have also risen in the past few years. The pathogenicity of Candida is credited to its aptitude to change between yeast and hyphal modes of growth. Candida spp produce biofilms on synthetic materials that protect them and facilitate drug resistance and act as a source for chronic and recurrent infections. Primarily, azoles antifungal agents are utilized to treat Candida infection that targets the ergosterol synthesis pathway in the cell wall. The development of antifungal resistance in Candida species is a major reason for treatment failure, and hence, there is a need to develop newer antifungal molecules and/or modifications of existing antifungals to make them more effective and less toxic. This has led researchers to oversee the plants to discover newer antimicrobials. Middle Eastern countries are well known for their landscape ranging from dry and sandy deserts to snow-capped mountains. However, they comprise enormous plant diversity with over 20,000 different species showing various types of bioactivities, such as anticancer, antidiabetic, and antimicrobial activities. Especially, the antifungal potential of these phytoproducts could be exploited in the clinical setting for therapy. The present review examines some of the promising alternative natural compounds that have been tested and found effective in treating Candida infections in vitro in some Middle Eastern countries.

Mineral Composition and Antioxidant Potential in the Common Poppy (Papaver rhoeas L.) Petal Infusions

The flowers of the common poppy are used for medicinal purposes, both internally and externally. They are reported to have antispasmodic and antitussive properties, to alleviate inflammatory conditions and soothe anxiety-related digestive problems. The aim of the study was to determine the antioxidant potential and the content of vitamin C, polyphenols, and minerals in infusions made from the petals of the common poppy at different temperatures. The infusions were made at various temperatures (25 °C, 70 °C, 80 °C, and 90 °C). The antioxidant potential and the content of polyphenols and vitamin C were determined by spectrophotometric methods. The mineral content was determined using the ICP-OES method. The total polyphenol content ranged from 135.2 to 137.24 ppm and that of vitamin C-from 15.47 to 15.78 mg/100 mL. The temperature of the water used to make the infusions did not appear to have a significant effect on these parameters. The temperature did, however, significantly affect the antioxidant potential of the infusions-the highest antioxidant activity (71.21% DPPH inhibition) was observed in the infusion prepared using water at 80 °C. The infusions included in the study contained a number of minerals. No significant effect of temperature was found for the content of K, Zn, Cu, Fe, and Ni in the infusions. On the other hand, the content of Ca in the infusions was significantly correlated with the increasing temperature of the water. It was concluded that poppy petal infusions may serve as a valuable dietary supplement, providing antioxidants and minerals required by the human body to function properly.

Tackling Antibiotic Resistance with Compounds of Natural Origin: A Comprehensive Review

Drug-resistant bacteria pose a serious threat to human health worldwide. Current antibiotics are losing efficacy and new antimicrobial agents are urgently needed. Living organisms are an invaluable source of antimicrobial compounds. The antimicrobial activity of the most representative natural products of animal, bacterial, fungal and plant origin are reviewed in this paper. Their activity against drug-resistant bacteria, their mechanisms of action, the possible development of resistance against them, their role in current medicine and their future perspectives are discussed. Electronic databases such as PubMed, Scopus and ScienceDirect were used to search scientific contributions until September 2020, using relevant keywords. Natural compounds of heterogeneous origins have been shown to possess antimicrobial capabilities, including against antibiotic-resistant bacteria. The most commonly found mechanisms of antimicrobial action are related to protein biosynthesis and alteration of cell walls and membranes. Various natural compounds, especially phytochemicals, have shown synergistic capacity with antibiotics. There is little literature on the development of specific resistance mechanisms against natural antimicrobial compounds. New technologies such as -omics, network pharmacology and informatics have the potential to identify and characterize new natural antimicrobial compounds in the future. This knowledge may be useful for the development of future therapeutic strategies.

Antiproliferative Properties of Papaver rhoeas Ovule Extracts and Derived Fractions Tested on HL60 Leukemia Human Cells

Papaver rhoeas plant is common in many regions worldwide and contributes to the landscape with its red flower. In the present study we first carried out morphological investigation by optical and scanning electron microscopy of the ovules within the ovary. After ovules' isolation we prepared extracts to test possible cytotoxic activities on HL60 leukemia human cells and investigated the extracts using thin-layer chromatography (TLC) and gas-chromatography/mass spectrometry (GC-MS). P. rhoeas ovules showed an elongated, round shape and the presence of ordered sculptures on the ovule surface. The ovule extracts showed cytotoxic activity on HL60 human cells mainly found in some TLC-isolated spots. Compounds consisting of active spots were identified by GC-MS investigations. Our findings on the P. rhoeas ovule compounds open perspectives for further investigations of TLC-isolated spots on other human cancer cell lines.

Antimicrobial Activity of Polyphenols and Alkaloids in Middle Eastern Plants

Antibiotic-resistant microorganisms have been an ever-growing concern over the past years. This has led researchers to direct their attention onto plants to be able to discover new possible antimicrobial compounds. The Middle East encompasses a wide spectrum of plant diversity with over 20,000 different species in habitats ranging from deserts to snow-capped mountains. Several plant secondary metabolites and their derivatives have been identified as possible antimicrobial agents. Among the secondary metabolites studied, alkaloids and polyphenols have shown strong antimicrobial activity. Polyphenols are one of the most numerous and diverse group of secondary metabolites; their antioxidant properties provide the basis for antimicrobial effects. Alkaloids provided the underlying structure for the development of several antibiotics with a diverse range of action. The ability of some plant secondary metabolites to act as resistance-modifying agents is a promising field in mitigating the spread of bacterial resistance.

Transcriptome Profiling of Two Ornamental and Medicinal Papaver Herbs

The Papaver spp. (Papaver rhoeas (Corn poppy) and Papaver nudicaule (Iceland poppy)) genera are ornamental and medicinal plants that are used for the isolation of alkaloid drugs. In this study, we generated 700 Mb of transcriptome sequences with the PacBio platform. They were assembled into 120,926 contigs, and 1185 (82.2%) of the benchmarking universal single-copy orthologs (BUSCO) core genes were completely present in our assembled transcriptome. Furthermore, using 128 Gb of Illumina sequences, the transcript expression was assessed at three stages of Papaver plant development (30, 60, and 90 days), from which we identified 137 differentially expressed transcripts. Furthermore, three co-occurrence heat maps are generated from 51 different plant genomes along with the Papaver transcriptome, i.e., secondary metabolite biosynthesis, isoquinoline alkaloid biosynthesis (BIA) pathway, and cytochrome. Sixty-nine transcripts in the BIA pathway along with 22 different alkaloids (quantified with LC-QTOF-MS/MS) were mapped into the BIA KEGG map (map00950). Finally, we identified 39 full-length cytochrome transcripts and compared them with other genomes. Collectively, this transcriptome data, along with the expression and quantitative metabolite profiles, provides an initial recording of secondary metabolites and their expression related to Papaver plant development. Moreover, these profiles could help to further detail the functional characterization of the various secondary metabolite biosynthesis and Papaver plant development associated problems.

Identification and metabolite profiling of alkaloids in aerial parts of Papaver rhoeas by liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry

Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty-five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine-type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.

An OMIC approach to elaborate the antibacterial mechanisms of different alkaloids

Plant-derived substances have regained interest in the fight against antibiotic resistance owing to their distinct antimicrobial mechanisms and multi-target properties. With the recent advances in instrumentation and analysis techniques, OMIC approaches are extensively used for target identification and elucidation of the mechanism of phytochemicals in drug discovery. In the current study, RNA sequencing based transcriptional profiling together with global differential protein expression analysis was used to comparatively elaborate the activities and the effects of the plant alkaloids boldine, bulbocapnine, and roemerine along with the well-known antimicrobial alkaloid berberine in Bacillus subtilis cells. The transcriptomic findings were validated by qPCR. Images from scanning electron microscope were obtained to visualize the effects on the whole-cells. The results showed that among the three selected alkaloids, only roemerine possessed antibacterial activity. Unlike berberine, which is susceptible to efflux through multidrug resistance pumps, roemerine accumulated in the cells. This in turn resulted in oxidative stress and building up of reactive oxygen species, which eventually deregulated various pathways such as iron uptake. Treatment with boldine or bulbocapnine slightly affected various metabolic pathways but has not changed the growth patterns at all.