A Bronchodilator Alkaloid (Vasicinone) from Adhatoda vasica Nees

Access to N-Fused Quinazolinones by Radical-Promoted Cascade Annulations of Alkenyl N-Cyanamides with Aromatic Aldehydes

A cascade radical cyclization of alkenyl N-cyanamides with aromatic aldehydes has been achieved for an expeditious synthesis of keto-methylated dihydropyrrolo-quinazolinones. Benzoyl radicals, generated from aryl aldehydes in the presence of di-tert-butyl peroxide (DTBP), promoted the domino annulations leading to distinctive functionalized quinazolinones in good yields. In addition, the robustness of the present protocol is validated by employing heterocyclic and natural product-based aldehydes.

Exploring the pharmacological and chemical aspects of pyrrolo-quinazoline derivatives in Adhatoda vasica

Adhatoda or Justicia is one of the biggest and complex genera of the Acanthaceae family. Adhatoda vasica is commonly known as 'Adosa'. It is an ayurvedic medicine with a medicinal history of more than a thousand years in India. Traditionally, it is used to treat cough, asthma, phlegm, bleeding hemorrhoids, for both adults and youth. This plant possesses antiarthritis, antiseptic, antimicrobial, anti-tuberculosis, anti-inflammatory and abortifacient properties. Alkaloids are the major phytoconstituents present in the plant in the form of pyrrolo-quinazoline derivatives viz vasicine, vasicinone, vasicinol, adhatodine, adhatodinine, adhavasinone and anisotine etc. The asserted objectives are to conduct a systematic review on the phytochemistry, pharmacology and traditional uses of A. vasica, as well as highlighting the challenges found in the research. This will promote the utilization of A. vasica at extract level and further development of new drug leads based on the compounds isolated and used for treatment of various ailments. The present review covers the literature survey from 1888 to 2023. The relevant data has been collected from various peer-reviwed journals, and books via Sci-Finder, PubMed, Science Direct, Google Scholar, EBSCO, online electronic journals, SpringerLink and Wiley. This paper aims to present a systematic review of known traditional applications, pharmacological and chemical aspects in Adhatoda vasica.

Discovery of extended product structural space of the fungal dioxygenase AsqJ

The fungal dioxygenase AsqJ catalyses the conversion of benzo[1,4]diazepine-2,5-diones into quinolone antibiotics. A second, alternative reaction pathway leads to a different biomedically important product class, the quinazolinones. Within this work, we explore the catalytic promiscuity of AsqJ by screening its activity across a broad range of functionalized substrates made accessible by solid-/liquid-phase peptide synthetic routes. These systematic investigations map the substrate tolerance of AsqJ within its two established pathways, revealing significant promiscuity, especially in the quinolone pathway. Most importantly, two further reactivities leading to new AsqJ product classes are discovered, thus significantly expanding the structural space accessible by this biosynthetic enzyme. Switching AsqJ product selectivity is achieved by subtle structural changes on the substrate, revealing a remarkable substrate-controlled product selectivity in enzyme catalysis. Our work paves the way for the biocatalytic synthesis of diverse biomedically important heterocyclic structural frameworks.

An iron-catalyzed domino reaction of donor-acceptor cyclopropanes: a diastereoselective approach towards diversely functionalized pyrrolo-quinazolines

An expeditious synthetic route to access functionalized pyrrolo[2,1-b]quinazoline scaffolds has been achieved via domino ring opening cyclization (DROC) reactions of donor-acceptor (D-A) cyclopropanes and 2-amino(methyl)aniline derivatives. This novel iron catalyzed transformation is amenable to a wide range of substrates. Three new C-N bonds and two rings were sequentially constructed in this divergent one-pot process. The advantages of simple operation, high yields and general applicability make this procedure highly attractive and practical too.

Rapid Synthesis of Luotonin A Derivatives via Synergistic Visible-Light Photoredox and Acid Catalysis

The merging of visible-light photoredox and acid catalysis allowed for an intramolecular Povarov cycloaddition reaction using eosin Y as the photocatalyst and TsOH·H₂O as the co-catalyst. A visible-light-promoted dehydrogenative cyclization protocol enabled the construction of Luotonin A derivatives with up to 97% yield.

Cyanomethylative cyclization of unactivated alkenes with nitriles for the synthesis of cyano-containing ring-fused quinazolin-4(3H)-ones

The synthesis of cyano-containing pyrrolo- and piperidino-quinazolinones was developed using alkyl nitriles through radical cascade addition/cyclization under metal-free conditions.

High-Throughput Detection of an Alkaloidal Plant Metabolome in Plant Extracts Using LC-ESI-QTOF-MS

Plant alkaloids represent a diverse group of nitrogen-containing natural products. These compounds are considered valuable in drug discovery and development. High-throughput identification of such plant secondary metabolites in complex plant extracts is essential for drug discovery, lead optimization, and understanding the biological pathway. The present study aims to rapidly identify different classes of alkaloids in plant extracts through the liquid chromatography with electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) approach using 161 isolated and purified alkaloids. These are biologically important unique alkaloids belonging to different sub-classes such as isoquinoline, quinoline, indole, tropane, pyridine, piperidine, quinolizidine, aporphine, steroidal, and terpenoid. The majority of these are not available commercially and are known to manifest valuable biological activities. Four pools of a maximum of 50 phytostandards each were prepared, based on their log P value to minimize co-elution for rapid and cost-effective analyses. MS/MS spectra were acquired in the positive ionization mode by using their [M + H]⁺ and/or [M + Na]⁺ with both the average collisional energy (25.5-62 eV) and individual collisional energies (10, 20, 30, and 40 eV). Accurate mass, high-resolution mass spectrometry (HR-MS) data, MS/MS data, and retention times were curated for each compound. The developed LC-MS/MS method was successfully used to interrogate and fast dereplicate alkaloids in 13 medicinal plant extracts and a herbal formulation. A total of 56 alkaloids were identified based on the reference standard retention times (RTs), HR-MS spectra, and/or MS/MS spectra. The MS data have been submitted to the MetaboLights online database (MTBLS2914). The mass spectrometric and chromatographic data will be useful for the discovery of new congeners and the study of biological pathways of alkaloids in the plant kingdom.

Novel hydroxybenzylamine-deoxyvasicinone hybrids as anticholinesterase therapeutics for Alzheimer's disease

A series of novel 2-hydroxybenzylamine-deoxyvasicinone hybrid analogs (8a-8n) have been synthesized and evaluated as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), and as inhibitors of amyloid peptide (Aβ_1-42) aggregation, for treatment of Alzheimer's disease (AD). These dual acting compounds exhibited good AChE inhibitory activities ranging from 0.34 to 6.35 µM. Analogs8g and 8n were found to be the most potent AChE inhibitors in the series with IC₅₀values of 0.38 µM and 0.34 µM, respectively. All the analogs (8a-8n) exhibited weak BuChE inhibitory activities ranging from 14.60 to 21.65 µM. Analogs8g and 8n exhibited BuChE with IC₅₀values of 15.38 µM and 14.60 µM, respectively, demonstrating that these analogs were greater than 40-fold more selective for inhibition of AChE over BuChE. Additionally, compounds8g and 8n were also found to be the best inhibitors of self-induced Aβ_1-42 peptide aggregation with IC₅₀values of 3.91 µM and 3.22 µM, respectively; 8g and 8n also inhibited AChE-induced Aβ_1-42 peptide aggregation by 68.7% and 72.6%, respectively. Kinetic analysis and molecular docking studies indicate that analogs 8g and 8n bind to a new allosteric pocket (site B) on AChE. In addition, the observed inhibition of AChE-induced Aβ_1-42 peptide aggregation by 8n is likely due to allosteric inhibition of the binding of this peptide at the CAS site on AChE. Overall, these results indicate that 8g and 8n are examples of dual-acting lead compounds for the development of highly effective anti-AD drugs.

Adhatoda Vasica attenuates inflammatory and hypoxic responses in preclinical mouse models: potential for repurposing in COVID-19-like conditions

BACKGROUND

COVID-19 pneumonia has been associated with severe acute hypoxia, sepsis-like states, thrombosis and chronic sequelae including persisting hypoxia and fibrosis. The molecular hypoxia response pathway has been associated with such pathologies and our recent observations on anti-hypoxic and anti-inflammatory effects of whole aqueous extract of Adhatoda Vasica (AV) prompted us to explore its effects on relevant preclinical mouse models.

METHODS

In this study, we tested the effect of whole aqueous extract of AV, in murine models of bleomycin induced pulmonary fibrosis, Cecum Ligation and Puncture (CLP) induced sepsis, and siRNA induced hypoxia-thrombosis phenotype. The effect on lung of AV treated naïve mice was also studied at transcriptome level. We also determined if the extract may have any effect on SARS-CoV2 replication.

RESULTS

Oral administration AV extract attenuates increased airway inflammation, levels of transforming growth factor-β1 (TGF-β1), IL-6, HIF-1α and improves the overall survival rates of mice in the models of pulmonary fibrosis and sepsis and rescues the siRNA induced inflammation and associated blood coagulation phenotypes in mice. We observed downregulation of hypoxia, inflammation, TGF-β1, and angiogenesis genes and upregulation of adaptive immunity-related genes in the lung transcriptome. AV treatment also reduced the viral load in Vero cells infected with SARS-CoV2.

CONCLUSION

Our results provide a scientific rationale for this ayurvedic herbal medicine in ameliorating the hypoxia-hyperinflammation features and highlights the repurposing potential of AV in COVID-19-like conditions.

Adhatoda vasica rescues the hypoxia-dependent severe asthma symptoms and mitochondrial dysfunction

Severe asthma is a chronic airway disease that exhibits poor response to conventional asthma therapies. Growing evidence suggests that elevated hypoxia increases the severity of asthmatic inflammation among patients and in model systems. In this study, we elucidate the therapeutic effects and mechanistic basis of Adhatoda vasica (AV) aqueous extract on mouse models of acute allergic as well as severe asthma subtypes at physiological, histopathological, and molecular levels. Oral administration of AV extract attenuates the increased airway resistance and inflammation in acute allergic asthmatic mice and alleviates the molecular signatures of steroid (dexamethasone) resistance like IL-17A, KC (murine IL-8 homologue), and HIF-1α (hypoxia-inducible factor-1α) in severe asthmatic mice. AV inhibits HIF-1α levels through restoration of expression of its negative regulator-PHD2 (prolyl hydroxylase domain-2). Alleviation of hypoxic response mediated by AV is further confirmed in the acute and severe asthma model. AV reverses cellular hypoxia-induced mitochondrial dysfunction in human bronchial epithelial cells-evident from bioenergetic profiles and morphological analysis of mitochondria. In silico docking of AV constituents reveal higher negative binding affinity for C and O-glycosides for HIF-1α, IL-6, Janus kinase 1/3, TNF-α, and TGF-β-key players of hypoxia inflammation. This study for the first time provides a molecular basis of action and effect of AV whole extract that is widely used in Ayurveda practice for diverse respiratory ailments. Further, through its effect on hypoxia-induced mitochondrial dysfunction, the study highlights its potential to treat severe steroid-resistant asthma.

Justicia adhatoda reveals two morphotypes with possible functional significance

Justicia adhatoda L. (Acanthaceae), an Old-World species of Justicia, is found in almost all geographical regions of India. Indian botanists have persistently used two accepted synonyms of J. adhatoda, namely, Adhatoda vasica and Adhatoda zeylanica, treating them as names of separate species, but without considering or making any reference to variation of forms in the species. Here, different aspects of variation-phenotypic, genotypic, and distributional-in Indian populations of J. adhatoda were studied to determine whether the two names might have been used to designate distinguishable forms of the species. We conducted field studies in different regions of India, laboratory studies of diverse phenotypic traits in experimental plots (anatomical, biochemical, reproductive, and morphometric), and a preliminary study of genetic variation using homologous cytochrome P450 gene fragments. We assessed herbarium samples from across India and the taxonomic literature for pointers indicating the presence of distinguishable forms. Population-level phenotypic and genetic variation pointed to the presence of two distinct morphotypes of the species, which separately tend to occur in dry and wet regions. Each form retains its original phenotype, either when the two forms are transplanted and cultivated together, or when found growing in regions (presumed introduced) outside its normal distributional range. Morphological studies and metabolic profiling (leaf and seed fatty acids, wax load and wax composition in leaf) suggest functional adaptation of the two forms, one to drier and the other to wetter regions. We could distinguish these forms in herbarium specimens dating back to 1821, but neither herbarium specimens nor the taxonomic literature reveal any reference to two forms. We propose that the forms be recognized as two distinct morphotypes of Justicia adhatoda.

Redox Condensations of o-Nitrobenzaldehydes with Amines under Mild Conditions: Total Synthesis of the Vasicinone Family

A total synthesis of the vasicinone family of natural products from bulk chemicals was developed. Reductive condensation of o-nitrobenzaldehydes with amines utilizing iron pentacarbonyl as a reducing agent followed by subsequent oxidation leads to a great variety of polycyclic nitrogen-containing heterocycles under mild conditions. Enantiomerically pure vasicinone, rutaecarpine, isaindigotone, and luotonin were synthesized from readily available starting materials like hydroxyproline, nitrobenzaldehyde, pyrrolidine, and piperidine in two to four operational steps without chromatography. The antifungal activity of all products was tested.

Induction of Autophagy by Vasicinone Protects Neural Cells from Mitochondrial Dysfunction and Attenuates Paraquat-Mediated Parkinson's Disease Associated α-Synuclein Levels

Mitochondrial dysfunction and disturbed mitochondrial dynamics were found to be common phenomena in the pathogenesis of Parkinson's disease (PD). Vasicinone is a quinazoline alkaloid from Adhatoda vasica. Here, we investigated the autophagy/mitophagy-enhancing effect of vasicinone and explored its neuroprotective mechanism in paraquat-mimic PD modal in SH-SY5Y cells. Vasicinone rescued the paraquat-induced loss of cell viability and mitochondrial membrane potential. Subsequently, the accumulation of mitochondrial reactive oxygen species (ROS) was balanced by an increase in the expression of antioxidant enzymes. Furthermore, vasicinone restored paraquat-impaired autophagy and mitophagy regulators DJ-1, PINK-1 and Parkin in SH-SY5Y cells. The vasicinone mediated autophagy pathways were abrogated by treatment with the autophagy inhibitor 3-MA, which lead to increases α-synuclein accumulation and decreased the expression of p-ULK and ATG proteins and the autophagy marker LC3-II compared to that observed without 3-MA treatment. These results demonstrated that vasicinone exerted neuroprotective effects by upregulating autophagy and PINK-1/Parkin mediated mitophagy in SH-SY5Y cells.

Green synthesis of Copper Oxide/Carbon nanocomposites using the leaf extract of Adhatoda vasica Nees, their characterization and antimicrobial activity

Copper Oxide/Carbon (CuO/C) nanocomposites were developed through the green method using the leaf extract of Adhatoda vasica at room temperature. Here, the leaf extract serves as a capping agent, reducing agent and a source of carbon for the formation of nanocomposites. As we know, this is the first article on the synthesis of CuO/C nanocomposites using this leaf extract. The nanocomposites were prepared by mixing the copper sulphate pentahydrate solution with the plant extract under certain conditions. The synthesized material was characterized by XRD, UV-Visible, FTIR, FE SEM, EDS, XPS and TGA. The results revealed that the synthesized material is a composite of copper oxide and functionalized graphene-like carbon. The SEM images indicated that the CuO/C nanoflakes had an average thickness of 7-11nm. Further, the composites were examined for antifungal activity and antibacterial activity. The nanocomposites showed significant antibacterial activity against the pathogenic bacterial strains Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus and antifungal activity against the fungi Aspergillus niger and Candida albicans. Also, the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal/Bactericidal Concentration (MFC/MBC) of the nanocomposites were determined against the fungus C. albicans and the bacteria K. pneumonia.

Novel polycyclic pyrroloquinazoline alkaloids from Anisotes trisulcus and their biological activity

Two new polycyclic pyrroloquinazoline alkaloids with unprecedented skeleton, anisulcusines A (1) and B (2), along with four known compounds (3-6), were identified from the aerial parts of Anisotes trisulcus (Forssk.) Nees. To our knowledge, anisulcusines A and B are the first polycyclic pyrroloquinazoline alkaloids that possess a unique N-methyl-1,2-dihydro-1'H-spiro[benzo[d][1,3]oxazine moiety. The chemical structures of the new compounds were elucidated through extensive spectroscopic analyses and high-resolution mass spectroscopy. Anisulcusine B (2) exerted moderate cytotoxic effect on cultured human hepatoma (HuH7) cells, whereas compounds 1 and 3-5 exhibited mild cell proliferative or growth stimulatory activity. HIGHLIGHTS Two new polycyclic pyrroloquinazoline alkaloids from Anisotes trisulcus. Structures were elucidated on the basis of 1D- and 2D-NMR and HR-ESI-MS spectra. Compound (2) exerted moderate cytotoxic effect against human hepatoma (HuH7) cells. Compounds (1, 3-5) exhibited mild cell proliferative or growth stimulatory activity.

Tocolytic activity assessment of the methanol leaf extract of Justicia flava Vahl (Acanthaceae) on mouse myometrial contractility and preliminary mass spectrometric determination of secondary metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Justicia flava are traditionally used in the South of Nigeria to prevent preterm births.

AIM OF THE STUDY

In this study, the activity of the methanol leaf extract of J. flava (JF) was investigated on uterine contractility in non-pregnant and pregnant isolated mouse tissues.

MATERIAL AND METHODS

The effects on spontaneous, oxytocin, and KCl-induced contractions were determined. The effects in calcium-free media were also determined. Possible mechanisms of activity were investigated using receptor and channel modulators. Mass spectrometric analysis was additionally performed on the leaf extract to identify secondary metabolites.

RESULTS

JF was observed to inhibit spontaneous, oxytocin and high KCl-induced uterine contractility. JF also inhibited contractions in Ca²⁺-free media. JF was found to exert its inhibitory effect via interaction with inositol triphosphate and ryanodine receptors and also through modulation of K⁺- channels. Lignans and alkaloids were identified with the lignans being the most abundant in JF.

CONCLUSION

JF has been shown to potently inhibit uterine contractions in non-pregnant and pregnant isolated mouse uterus. The inhibitory activity of JF has been shown to occur via blockade of extracellular and intracellular calcium entry and these effects may be due to the lignans identified in - JF. JF has therefore been shown in this study to be a lead plant in the discovery of new drugs with uterine inhibitory activity.

Effect of Vasicinone against Paraquat-Induced MAPK/p53-Mediated Apoptosis via the IGF-1R/PI3K/AKT Pathway in a Parkinson's Disease-Associated SH-SY5Y Cell Model

Vasicinone is a quinazoline alkaloid isolated from the Adhatoda vasica plant. In this study, we explored the neuroprotective effect and underlying molecular mechanism of vasicinone against paraquat-induced cellular apoptosis in SH-SY5Y cells. Vasicinone reduced the paraquat-induced loss of cell viability, rescued terminal deoxynucleotide transferase-mediated dUTP nick end-labeling (TUNEL)-positive apoptotic nuclei, and suppressed generation of reactive oxygen species (ROS) in a dose-dependent manner. Western blotting analysis revealed that vasicinone increased the phosphorylation of IGF1R/PI3K/AKT cell survival signaling molecules and downregulated the paraquat-induced, mitogen-activated protein kinase (MAPK)/c-Jun N-terminal kinase (JNK)-mediated apoptotic pathways compared to that observed in cells not treated with vasicinone. This protection depended critically on the activation of IGF1R, and the silencing of IGF1R by siRNA completely abrogated the protective effect of vasicinone in SH-SY5Y cells. Our findings indicated that vasicinone is a potential candidate for the treatment of Parkinson’s disease and possibly other oxidative stress-related neurodegenerative disorders.

Photoinitiated Cascade for Rapid Access to Pyrroloquinazolinone Core of Vasicinone, Luotonins, and Related Alkaloids

Furylimines of aromatic o-nitro aldehydes undergo a photoinduced cascade transformation offering rapid atom- and step-economical access to complex polyheterocyclic scaffolds possessing a privileged pyrroloquinazolinone core.

Traditional medicinal plants used for respiratory disorders in Pakistan: a review of the ethno-medicinal and pharmacological evidence

Respiratory disorders are a common cause of malady and demise in Pakistan due to its remoteness, cold and harsh climatic conditions as well as scarce health care facilities. The people rely upon the indigenous plant resources to cure various respiratory disorders. The primary objective of this review was to assemble all available ethno-medicinal data of plants used for respiratory disorders in Pakistan. Pharmacological activity of these plants (based upon published scientific research), distribution, diversity, use, preparation methods, economical value, conservation status and various available herbal products of some plants have also been explored. This study scrutinized various electronic databases for the literature on medicinal plants used in Pakistan to treat respiratory disorders. A total of 384 species belonging to 85 families used to treat respiratory disorders in Pakistan has been documented. Cough was the disorder treated by the highest number of species (214) followed by asthma (150), cold (57) and bronchitis (56). Most of the plants belongs to Asteraceae (32) and Solanaceae family (32) followed by moraceae (17), Poaceae (13), and Amaranthaceae (13) with their habit mostly of herb (219) followed by Shrub (112) and tree (69). Traditional healers in the region mostly prepare ethno medicinal recipes from leaves (24%) and roots (11%) in the form of decoction. Among the reported conservation status of 51 plant species, 5 were endangered, 1 critically endangered, 11 vulnerable, 14 rare, 16 least concern, 3 infrequent and 1 near threatened. We found only 53 plants on which pharmacological studies were conducted and 17 plants being used in herbal products available commercially for respiratory disorders. We showed the diversity and importance of medicinal plants used to treat respiratory disorders in the traditional health care system of Pakistan. As such disorders are still causing several deaths each year, it is of the utmost importance to conduct phytochemical and pharmacological studies on the most promising species. It is also crucial to increase access to traditional medicine, especially in rural areas. Threatened species need special attention for traditional herbal medicine to be exploited sustainably.

Anti-Proliferative Activities of Vasicinone on Lung Carcinoma Cells Mediated via Activation of Both Mitochondria-Dependent and Independent Pathways

Vasicinone, a quinazoline alkaloid from Adhatoda vasica Nees. is well known for its bronchodilator activity. However its antiproliferative activities is yet to be elucidated. Here-in we investigated the anti-proliferative effect of vasicinone and its underlying mechanism against A549 lung carcinoma cells. The A549 cells upon treatment with various doses of vasicinone (10, 30, 50, 70 µM) for 72 h showed significant decrease in cell viability. Vasicinone treatment also showed DNA fragmentation, LDH leakage, and disruption of mitochondrial potential, and lower wound healing ability in A549 cells. The Annexin V/PI staining showed disrupted plasma membrane integrity and permeability of PI in treated cells. Moreover vasicinone treatment also lead to down regulation of Bcl-2, Fas death receptor and up regulation of PARP, BAD and cytochrome c, suggesting the anti-proliferative nature of vasicinone which mediated apoptosis through both Fas death receptors as well as Bcl-2 regulated signaling. Furthermore, our preliminary studies with vasicinone treatment also showed to lower the ROS levels in A549 cells and have potential free radical scavenging (DPPH, Hydroxyl) activity and ferric reducing power in cell free systems. Thus combining all, vasicinone may be used to develop a new therapeutic agent against oxidative stress induced lung cancer.

Biologically active quinoline and quinazoline alkaloids part I

Quinoline and quinazoline alkaloids, two important classes of N-based heterocyclic compounds, have attracted tremendous attention from researchers worldwide since the 19th century. Over the past 200 years, many compounds from these two classes were isolated from natural sources, and most of them and their modified analogs possess significant bioactivities. Quinine and camptothecin are two of the most famous and important quinoline alkaloids, and their discoveries opened new areas in antimalarial and anticancer drug development, respectively. In this review, we survey the literature on bioactive alkaloids from these two classes and highlight research achievements prior to the year 2008 (Part I). Over 200 molecules with a broad range of bioactivities, including antitumor, antimalarial, antibacterial and antifungal, antiparasitic and insecticidal, antiviral, antiplatelet, anti-inflammatory, herbicidal, antioxidant and other activities, were reviewed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.

Total synthesis of natural productsviairidium catalysis

An overview of the highlights in total synthesis of natural products using iridium as a catalyst is given.

Effect of elicitors on the production of pyrroloquinazoline alkaloids by stimulating anthranilate synthase activity in Adhatoda vasica Nees cell cultures

Pyrroloquinazoline alkaloids are medicinally important compounds, determined by HPLC from cell cultures of Adhatoda vasica . The maximum production of vasicinone (12-fold) and vasicine (8.3-fold) was enhanced by stimulating the anthranilate synthase activity via feeding of tryptophan and sorbitol. The decoction of Adhatoda vasica leaves is used for the treatment of throat irritations, inflammations and recommended as expectorant. The plant species contains pyrroloquinazoline alkaloids and has been reported to demonstrate various biological activities. To investigate the effect of elicitors to increase the production of alkaloids, five groups (auxins and cytokinins, biotic elicitors, polysaccharides, amino acids and salts) of elicitors were evaluated. Maximum production of vasicinone (72.74 ± 0.74 mg/g DW; 12-fold) and vasicine (99.44 ± 0.28 mg/g DW; 8.3-fold) was enhanced by feeding of tryptophan and sorbitol at 50 mM concentration in cell cultures. Fourteen free amino acids were estimated from the elicited cells. Sorbitol stimulated up to a maximum accumulation of serine (8.2-fold). The maximal anthranilate synthase (AS) activity (7.5 ± 0.47 pkat/mg protein; 2.9-fold) was induced by salicylic acid and sorbitol. Anthranilate synthase functions as rate-limiting factor for the biosynthesis of pyrroloquinazoline alkaloids. Our results support the widespread use of tryptophan and sorbitol as elicitors to raise the production of vasicinone, vasicine, 2-acetyl benzyl amine and other pyrroloquinazoline alkaloids in cell cultures of A. vasica.

Site-Selective Copper-Catalyzed Amination and Azidation of Arenes and Heteroarenes via Deprotonative Zincation

Arene amination is achieved by site-selective C-H zincation followed by copper-catalyzed coupling with O-benzoylhydroxylamines under mild conditions. Key to this success is ortho-zincation mediated by lithium amidodiethylzincate base that is effective for a wide range of arenes, including nonactivated arenes bearing simple functionalities such as fluoride, chloride, ester, amide, ether, nitrile, and trifluoromethyl groups as well as heteroarenes including indole, thiophene, pyridine, and isoquinoline. An analogous C-H azidation is also accomplished using azidoiodinane for direct introduction of a useful azide group onto a broad scope of arenes and heteroarenes. These new transformations offer rapid access to valuable and diverse chemical space of aminoarenes. Their broad applications in organic synthesis and drug discovery are demonstrated in the synthesis of novel analogues of natural product (-)-nicotine and antidepressant sertraline by late-stage amination and azidation reactions.

A reappraisal of the mucoactive activity and clinical efficacy of bromhexine

Since its introduction to the market in 1963, bromhexine, an over-the-counter drug, has been investigated for its activity in animal models and in humans with diverse respiratory conditions. Bromhexine is a derivate of the Adhatoda vasica plant used in some countries for the treatment of various respiratory diseases. Bromhexine has been found to enhance the secretion of various mucus components by modifying the physicochemical characteristics of mucus. These changes, in turn, increase mucociliary clearance and reduce cough. Principal clinical research studies were primarily developed in an era when stringent methodological approaches and good clinical practices were not developed yet. Clinical studies were conducted mainly in patients with chronic bronchitis and in patients with various respiratory diseases, and demonstrated the efficacy of bromhexine in improving respiratory symptoms. Furthermore, the co-administration of antibiotics with bromhexine amplified the actions of the antibiotic. Although the clinical evidence shows only modest but positive results, bromhexine is indicated for its mucoactive activity. Larger trials with adequate methodology are required to identify when treatment with bromhexine can improve clinical outcomes.

Synthesis of Ofornine mimics from natural product l-vasicine as anti-hypertensive agents

We report the chemical synthesis of Ofornine mimics from l-vasicine, structure-activity relationship studies and their in vivo screening for anti-hypertensive action in Wistar rats. It was observed that most of the analogs possessed anti-hypertensive effect; however, the duration of the effect was variable and mostly transient. The results demonstrated that the analogs 12, 13, 14, 15, and 16 showed a sharp and significant decrease in systolic and diastolic blood pressure for 30-60min after intravenous administration. Analog (S)-(3-hydroxypyrrolidin-1-yl)(2-(pyridin-4-ylamino)phenyl)methanone (8) showed a significant decrease in blood pressure in a dose dependent manner whose maximal response lowered to 79.29±4.26mmHg of SBP and 62.55±2.9 of DBP at 10mg/kg intravenous dose. Further, the significant anti-hypertensive effect of 8 lasted for about 2.5h at 10mg/kg dose. We also evaluated the acute toxicity of the analog 8 as per the OECD guidelines and the compound was found to be safe up to the dose of 2000mg/kg body weight. These preclinical findings suggest that the analog 8 could be considered as a promising lead and a durable anti-hypertensive drug candidate and deserves further investigation. The SAR studies clearly showed that the amide, hydroxyl and pyridine ring plays important role in showing the activity.

The genus Sida L. - A traditional medicine: Its ethnopharmacological, phytochemical and pharmacological data for commercial exploitation in herbal drugs industry

ETHNOPHARMACOLOGICAL RELEVANCE

Sida L. (Malvaceae) has been used for centuries in traditional medicines in different countries for the prevention and treatment of different diseases such as diarrhea, dysentery, gastrointestinal and urinary infections, malarial and other fevers, childbirth and miscarriage problems, skin ailments, cardiac and neural problems, asthma, bronchitis and other respiratory problems, weight loss aid, rheumatic and other inflammations, tuberculosis, etc.

AIMS OF THIS REVIEW

To assess the scientific evidence for therapeutic potential of Sida L. and to identify the gaps of future research needs.

METHODS

The available information on the ethnomedicinal uses, phytochemistry, pharmacology and toxicology of Sida species was collected via a library and electronic searches in SciFinder, PubMed, ScienceDirect, Google Scholar for the period, 1933-2015.

RESULTS

A variety of ethnomedicinal uses of Sida species have been found in India, China, Afrian and American countries. Phytochemical investigation of this genus has resulted in identification of about 142 chemical constituents, among which alkaloids, flavonoids and ecdysteroids are the predominant groups. The crude extracts and isolates have exhibited a wide spectrum of in vitro and in vivo pharmacological effects involving antimicrobial, analgesic, anti-inflammatory, abortifacient, neuroprotective, cardiovascular and cardioprotective, antimalarial, antitubercular, antidiabetic and antiobesity, antioxidant and nephroprotective activities among others. Ethnopharmacological preparations containing Sida species as an ingredient in India, African and American countries possess good efficacy in health disorders. From the toxicity perspective, only three Sida species have been assessed and found safe for oral use in rats.

CONCLUSIONS

Pharmacological results supported some of the uses of Sida species in the traditional medicine. Alkaloids, flavonoids, other phenolics and ecdysteroids were perhaps responsible for the activities of extracts of the plants of this genus. No clinical study was reported. The detailed study on mechanism of action of isolates and extracts and their clinical study are needed for their use in modern medicine. More attention should be paid to Sida acuta, Sida cordifolia, Sida spinosa, Sida rhombifolia and Sida veronicaefolia in the domain of diarrhea, dysentery, gastrointestinal and urinary infections, skin ailments, asthma, bronchitis and other respiratory problems, malaria, childbirth and miscarriage problems, cardiac and neural problems, weight loss aid, and rheumatic and other inflammations, etc. Furthermore, detailed study on quality and safety assurance data on available ethnopharmacological preparations is needed for their commercial exploitation in local and global markets.

Antitussive effect of a fixed combination of Justicia adhatoda, Echinacea purpurea and Eleutherococcus senticosus extracts in patients with acute upper respiratory tract infection: A comparative, randomized, double-blind, placebo-controlled study

BACKGROUND

Kan Jang® oral solution (KJ) is a fixed combination of aqueous ethanolic extracts of Justicia adhatoda L. leaf, Echinacea purpurea (L.) Moench root, and Eleutherococcus senticosus (Rupr. & Maxim.) Harms root. It is approved in Scandinavia as an herbal medicinal product for respiratory tract infection treatment.

PURPOSE

The present clinical trial aimed to compare the antitussive effect of KJ with placebo (PL) and bromhexine (BH) among patients of 18-65 years old with non-complicated upper respiratory infections (URI; i.e., common cold).

STUDY DESIGN

We performed a parallel-group, randomized, double-blinded, placebo-controlled trial in in 177 patients with acute URI over a 5 day period.

METHODS

We investigated the antitussive effects of a KJ (30 ml/day; 762 mg genuine extracts with standardized contents of 0.2 mg/ml vasicine, 0.8 mg/ml chicoric acid, and 0.03 mg/ml eleutherosides B and E), bromhexine hydrochloride (24 mg/30 ml/day) and PL on cough and blood markers. The primary outcome was cough relief, which was assessed as the change of cough frequency from baseline (cough index). Secondary outcomes were safety with regards to reported adverse events (AEs) and hematological data.

RESULTS

Both KJ and BH relieved cough more effectively than placebo. On the third and fourth days of treatment, we observed faster improvement in the group receiving KJ compared to in the groups receiving BH (100%) or PL (100%), indicating a slightly shorter recovery time in the KJ group. KJ showed a good tolerability and safety profile.

CONCLUSION

KJ exerted significant antitussive effects in URI. The present data further support the therapeutic use of KJ in upper respiratory tract infections.

In vitro exposure of Adhatoda zeylanica to human renal cells lacks acute toxicity

Adhatoda zeylanica is a dietary supplement ingredient present in several types of dietary supplements, including weight loss, respiratory relief, and immune regulating products. Due to its reported wide range of uses in folk medicine, it was hypothesized that it may have the potential to target multiple organs and lead to a range of toxicity features. As a preliminary evaluation of the safety of this herbal ingredient, an investigation into its effects on the kidney was sought. An in vitro study of its potential nephrotoxicity using the HK-2 human proximal tubule cell line in a variety of functional indicators was performed to capture both general forms of cellular toxicity as well as ones that are specific to proximal tubules. A. zeylanica was only capable of inducing detrimental short-term toxicity to HK-2 cells at relatively high treatment concentrations when exposed directly to the cells. The lack of acute and potent toxicity of A. zeylanica under our experimental conditions calls for further studies to better define its toxicant threshold and establish safe dosage levels.

Antitussive, expectorant, and bronchodilating effects of quinazoline alkaloids (±)-vasicine, deoxyvasicine, and (±)-vasicinone from aerial parts of Peganum harmala L

BACKGROUND

The aerial parts of Peganum harmala L. (APP) is a well-known and effective herbal medicine in China, and has been commonly used for treating various ailments, including cough and asthma.

OBJECTIVES

To evaluate the antitussive, expectorant, and bronchodilating effects of the quinazoline alkaloids (±)-vasicine (VAS), deoxyvasicine (DVAS) (both isolated from the alkaloid fraction of APP) and (±)-vasicinone (VAO) (synthesized from VAS).

METHODS

The three quinazoline alkaloids were tested as antitussive on cough models in mice and guinea pigs. VAO was synthesized from VAS via the oxidation of hydrogen peroxide. VAS, VAO, and DVAS were orally administered at dosages of 5, 15, and 45 mg/kg. Cough in these models was induced by ammonia, capsaicin, and citric acid. Phenol red secretion experiments in mice were performed to evaluate the expectorant activity of the alkaloids. Bronchodilating effects were evaluated by using a bronchoconstrictive induced by acetylcholine chloride and histamine in guinea pigs.

RESULTS

In antitussive tests, VAS, VAO, and DVAS significantly inhibited coughing frequency and prolonged the cough latency period in animals. At the highest doses tested (45 mg/kg), they showed antitussive activities similar to codeine phosphate (30 mg/kg) in mice and guinea pigs. Expectorant evaluation showed that VAS, VAO, and DVAS could significantly increase phenol red secretion in mice by 0.54-, 0.79- and 0.97-fold, by 0.60-, 0.99-, and 1.06-fold, and by 0.46-, 0.73-, and 0.96-fold, respectively, at dosages of 5, 15, and 45 mg/kg compared with the control (0.5% CMC-Na, 20 ml/kg). Ammonium chloride at 1500 mg/kg increased phenol red secretion in mice by 0.97-fold compared with the control. Bronchodilation tests showed that VAS, VAO, and DVAS prolonged the pre-convulsive time for 28.59%, 57.21%, and 29.66%, respectively, at a dose of 45 mg/kg in guinea pigs, whereas aminophylline prolonged the pre-convulsive time by 46.98% compared with pretreatment.

CONCLUSIONS

Quinazoline alkaloids VAS, VAO, and DVAS have significant antitussive, expectorant, and bronchodilating activities. VAS, VAO, and DVAS are the active ingredients in APP, which can be used to treat respiratory disease.

Direct access to pyrido/pyrrolo[2,1-b]quinazolin-9(1H)-ones through silver-mediated intramolecular alkyne hydroamination reactions

We report a synthetic methodology for the construction of the fused heterocyclic compounds pyrido[2,1-b]quinazolin-9(1H)-ones and pyrrolo[2,1-b]quinazolin-9(1H)-ones through an AgOTf-catalyzed intramolecular alkyne hydroamination reaction. The methodology is applicable to a wide scope of substrates and produces a series of fused quinazolinone heterocycles in good to excellent yields.

Antibacterial Activity of Green Synthesized Silver Nanoparticles Using Vasaka (Justicia adhatoda L.) Leaf Extract

There is an increasing demand for silver nanoparticles due to its wide applicability in various area of biological science such as in field of antimicrobial and therapeutics, biosensing, drug delivery etc. To use in bioprocess the silver nanoparticles should be biocompatible and free from toxic chemicals. In the present study we report a cost effective and environment friendly route for green synthesis of silver nanoparticles using Vasaka (Justicia adhatoda L.) leaf extract as reducing as well as capping agent. This plant has been opted for the present study for its known medicinal properties and it is easily available. The biosynthesized silver nanoparticles are characterized by UV-Vis spectroscopy and TEM analysis. It is observed the nanoparticles are well shaped and the average particle size is 20 nm in the range of 5-50 nm. The antibacterial activity of these nanoparticles against Pseudomonas aeruginosa MTCC 741 has been measured by disc diffusion method, agar cup assay and serial dilution turbidity measurement assay. The results show green synthesized silver nanoparticles, using Vasaka leaf extract, have a potential to inhibit the growth of bacteria.

Anti-inflammatory and antimicrobial properties of pyrroloquinazoline alkaloids from Adhatoda vasica Nees

Adhatoda vasica Nees, Acanthaceae, is well known plant in Ayurveda and Unani medicine. The purpose of this study was to characterize the most bioactive phytochemicals viz., vasicine, vasicinone, vasicine acetate, 2-acetyl benzyl amine, vasicinolone present in the chloroform fraction having anti-inflammatory and antimicrobial activities. The anti-inflammatory activity was tested by using carrageenan and CFA-model induced paw oedema. The antimicrobial activity of isolated compounds was assessed by using the microdilution method. The observed results revealed that vasicine showed most potent anti-inflammatory effects (59.51%) at the dose of 20.0mg/kg at 6h after carrageenan injection and maximum inhibition rate was observed of vasicinone (63.94%) at the dose of 10.0mg/kg at 4 days after CFA injection. The strong antibacterial activity was exhibited by vasicine at 20μg/ml dose against E. coli and also demonstrated maximum antifungal activity against C. albicans at the dose of >55μg/ml. All the five alkaloids demonstrated significant anti-inflammatory and antimicrobial activities.