Harmine: evaluation of its antileishmanial properties in various vesicular delivery systems

1,3-Substituted β-Carboline Derivatives as Potent Chemotherapy for the Treatment of Cystic Echinococcosis

Echinococcosis is a global public health issue that generally occurs in areas with developed animal husbandry. In search of safe and effective therapeutic agents against echinococcosis, we designed and synthesized new 1,3-substituted β-carboline derivatives based on harmine. Among them, compounds 1a, 1c, and 1e displayed potent inhibitory activity against Echinococcus granulosus in vitro, significantly better than albendazole and harmine. The morphological detection revealed that 1a, 1c, and 1e significantly changed the ultrastructure of Echinococcus granulosus protoscolices (PSCs). Furthermore, pharmacokinetic studies suggested that 1a possessed a better metabolic property. Encouragingly, 1a exhibited a highest cyst inhibition rate as 76.8% in vivo and did not display neurotoxicity in mice. Further mechanistic research illustrated that 1a has the potential to induce autophagy in PSCs, which may be responsible for the therapeutic effect of the drugs. Together, 1a could be a promising therapeutic agent against echinococcosis, warranting further study.

Simple naturally occurring β-carboline alkaloids – role in sustainable theranostics

This review is a brief treatise on some simple β-carboline alkaloids that are abundantly available in plants, animals and foodstuff. These alkaloids are well known for their pharmacological action as well as their allelopathic behaviour. The focus of this review is on sustainable use of naturally occurring compounds in safeguarding human health and protecting our environment at large i.e. the prospective applications of these molecules for Sustainable Theranostics. The review commences with an initial introduction to the β-carboline alkaloids, followed by an outlay of their geographical distribution and natural abundance, then the basic structure and building units of the simplest β-carboline alkaloids have been mentioned. This is followed by a discussion on the important methods of extraction from natural sources both plants and animals. Then the foundation for the use of these alkaloids in Sustainable Theranostics has been built by discussing their interesting photophysics, interactions with important biological molecules and an extensive survey of their therapeutic potential and allelopathic behaviour. Finally the review ends with a silver lining mentioning the future prospective applications of these alkaloids with special relevance to sustainability issues.

Overcoming epistemic injustices in the biomedical study of ayahuasca: Towards ethical and sustainable regulation

After decades of biomedical research on ayahuasca's molecular compounds and their physiological effects, recent clinical trials show evidence of therapeutic potential for depression. However, indigenous peoples have been using ayahuasca therapeutically for a very long time, and thus we question the epistemic authority attributed to scientific studies, proposing that epistemic injustices were committed with practical, cultural, social, and legal consequences. We question epistemic authority based on the double-blind design, the molecularization discourse, and contextual issues about safety. We propose a new approach to foster epistemically fair research, outlining how to enforce indigenous rights, considering the Brazilian, Peruvian, and Colombian cases. Indigenous peoples have the right to maintain, control, protect, and develop their biocultural heritage, traditional knowledge, and cultural expressions, including traditional medicine practices. New regulations about ayahuasca must respect the free, prior, and informed consent of indigenous peoples according to the International Labor Organization Indigenous and Tribal Peoples Convention no. 169. The declaration of the ayahuasca complex as a national cultural heritage may prevent patenting from third parties, fostering the development of traditional medicine. When involving isolated compounds derived from traditional knowledge, benefit-sharing agreements are mandatory according to the United Nations' Convention on Biological Diversity. Considering the extremely high demand to treat millions of depressed patients, the medicalization of ayahuasca without adequate regulation respectful of indigenous rights can be detrimental to indigenous peoples and their management of local environments, potentially harming the sustainability of the plants and of the Amazon itself, which is approaching its dieback tipping point.

Antibacterial, Antifungal, Antiviral, and Antiparasitic Activities of Peganum harmala and Its Ingredients: A Review

Infectious diseases have always been the number one enemy threatening health and well-being. With increasing numbers of infectious diseases, growing resistance of pathogens, and declining roles of antibiotics in the treatment of infectious diseases, it is becoming increasingly difficult to treat new infectious diseases, and there is an urgent need to develop new antibiotics to change the situation. Natural products tend to exhibit many special biological properties. The genus Peganum (Zygophyllaceae) has been used, for a long time, to treat cough, asthma, lumbago, hypertension, diabetes, and Alzheimer’s disease. Over the past two decades, a growing number of studies have shown that components from Peganum harmala Linn and its derivatives can inhibit a variety of microorganisms by inducing the accumulation of ROS in microorganisms, damaging cell membranes, thickening cell walls, disturbing cytoplasm, and interfering with DNA synthesis. In this paper, we provide a review on the antibacterial, antifungal, antiviral, and antiparasitic activities of P. harmala, with a view to contribute to research on utilizing P. harmala for medicinal applicaitons and to provide a reference in the field of antimicrobial and a basis for the development of natural antimicrobial agents for the treatment of infectious diseases.

Activity of alkaloids from Aspidosperma nitidum against Leishmania (Leishmania) amazonensis

This study evaluated the morphological changes caused by fractions and subfractions, obtained from barks of Aspidosperna nitidum, against L. (L.) amazonensis promastigotes. The ethanolic extract (EE) obtained through the maceration of trunk barks was subjected to an acid-base partition, resulting the neutral (FN) and the alkaloid (FA) fractions, and fractionation under reflux, yielded hexane (FrHEX), dichloromethane (FrDCL), ethyl acetate (FrACoET), and methanol (FrMEOH) fractions. The FA was fractionated and three subfractions (SF5-6, SF8, and SF9) were obtained and analyzed by HPLC-DAD and 1H NMR. The antipromastigote activity of all samples was evaluated by MTT, after that, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for the active fractions were performed. Chromatographic analyzes suggest the presence of alkaloids in EE, FN, FA, and FrDCL. The fractionation of FA led to the isolation of the indole alkaloid dihydrocorynantheol (SF8 fractions). The SF5-6, dihydrocorynantheol and SF-9 samples were active against promastigotes, while FrDCL was moderately active. The SEM analysis revealed cell rounding and changes in the flagellum of the parasites. In the TEM analysis, the treated promastigotes showed changes in flagellar pocket and kinetoplast, and presence of lipid inclusions. These results suggest that alkaloids isolated from A. nitidum are promising as leishmanicidal.

Enhanced Glioblastoma Selectivity of Harmine via the Albumin Carrier

Glioblastoma, the most common tumor in the brain, has witnessed very little clinical progress over the last decades. Exploring and discovering new therapeutic strategies for glioblastoma has become a critical problem. Harmine (HM), belonging to the beta-carboline alkaloid, is a natural product and isolated from the seeds of Peganum harmala L., which own notable antitumor activity in vitro. However, the poor water solubility and less selectivity of HM severely limit its clinical use. For enhancing its selective ability to tumor cells, we fabricated a kind of protein nanoparticles (BSA-HM NPs), composed of the modified bovine serum albumin (BSA) and HM. It was substantiated through in vitro and in vivo experiment that BSA-HM NPs could predominantly accumulate in tumor tissues and exhibited remarkably enhanced antitumor efficacy. This study provides a promising strategy to improve the bioavailability and avoid side effects of HM as antitumor agents by choosing BSA as carriers.

Antimicrobial Activity of a Repurposed Harmine-Derived Compound on Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates

Objectives

The spread of antibiotic resistant bacteria is an important threat for human health. Acinetobacter baumannii bacteria impose such a major issue, as multidrug- to pandrug-resistant strains have been isolated, rendering some infections untreatable. In this context, carbapenem-resistant A. baumannii bacteria were ranked as top priority by both WHO and CDC. In addition, A. baumannii bacteria survive in harsh environments, being capable of resisting to disinfectants and to persist prolonged periods of desiccation. Due to the high degree of variability found in A. baumannii isolates, the search for new antibacterials is very challenging because of the requirement of drug target conservation amongst the different strains. Here, we screened a chemical library to identify compounds active against several reference strains and carbapenem-resistant A. baumannii bacteria.

Methods

A repurposing drug screen was undertaken to identify A. baumannii growth inhibitors. One hit was further characterized by determining the IC₅₀ and testing the activity on 43 modern clinical A. baumannii isolates, amongst which 40 are carbapenem-resistant.

Results

The repurposing screen led to the identification of a harmine-derived compound, called HDC1, which proves to have bactericidal activity on the multidrug-resistant AB5075-VUB reference strain with an IC₅₀ of 48.23 µM. In addition, HDC1 impairs growth of 43 clinical A. baumannii isolates.

Conclusions

We identified a compound with inhibitory activity on all tested strains, including carbapenem-resistant clinical A. baumannii isolates.

Harmine is an effective therapeutic small molecule for the treatment of cardiac hypertrophy

Harmine is a β-carboline alkaloid isolated from Banisteria caapi and Peganum harmala L with various pharmacological activities, including antioxidant, anti-inflammatory, antitumor, anti-depressant, and anti-leishmanial capabilities. Nevertheless, the pharmacological effect of harmine on cardiomyocytes and heart muscle has not been reported. Here we found a protective effect of harmine on cardiac hypertrophy in spontaneously hypertensive rats in vivo. Further, harmine could inhibit the phenotypes of norepinephrine-induced hypertrophy in human embryonic stem cell-derived cardiomyocytes in vitro. It reduced the enlarged cell surface area, reversed the increased calcium handling and contractility, and downregulated expression of hypertrophy-related genes in norepinephrine-induced hypertrophy of human cardiomyocytes derived from embryonic stem cells. We further showed that one of the potential underlying mechanism by which harmine alleviates cardiac hypertrophy relied on inhibition of NF-κB phosphorylation and the stimulated inflammatory cytokines in pathological ventricular remodeling. Our data suggest that harmine is a promising therapeutic agent for cardiac hypertrophy independent of blood pressure modulation and could be a promising addition of current medications for cardiac hypertrophy.

Natural Bioactive Compounds Targeting Epigenetic Pathways in Cancer: A Review on Alkaloids, Terpenoids, Quinones, and Isothiocyanates

Cancer is one of the most complex and systemic diseases affecting the health of mankind, causing major deaths with a significant increase. This pathology is caused by several risk factors, of which genetic disturbances constitute the major elements, which not only initiate tumor transformation but also epigenetic disturbances which are linked to it and which can induce transcriptional instability. Indeed, the involvement of epigenetic disturbances in cancer has been the subject of correlations today, in addition to the use of drugs that operate specifically on different epigenetic pathways. Natural molecules, especially those isolated from medicinal plants, have shown anticancer effects linked to mechanisms of action. The objective of this review is to explore the anticancer effects of alkaloids, terpenoids, quinones, and isothiocyanates.

In vitro Effect of Harmine Alkaloid and Its N-Methyl Derivatives Against Toxoplasma gondii

Toxoplasmosis is one of the most prevalent and neglected zoonotic global diseases caused by Toxoplasma gondii. The current pharmacological treatments show clinical limitations, and therefore, the search for new drugs is an urgent need in order to eradicate this infection. Due to their intrinsic biological activities, β-carboline (βC) alkaloids might represent a good alternative that deserves further investigations. In this context, the in vitro anti-T. gondii activity of three βCs, harmine (1), 2-methyl-harminium (2), and 9-methyl-harmine (3), was evaluated herein. Briefly, the three alkaloids exerted direct effects on the parasite invasion and/or replication capability. Replication rates of intracellular treated tachyzoites were also affected in a dose-dependent manner, at noncytotoxic concentrations for host cells. Additionally, cell cycle analysis revealed that both methyl-derivatives 2 and 3 induce parasite arrest in S/M phases. Compound 3 showed the highest irreversible parasite growth inhibition, with a half maximal inhibitory concentration (IC50) value of 1.8 ± 0.2 μM and a selectivity index (SI) of 17.2 at 4 days post infection. Due to high replication rates, tachyzoites are frequently subjected to DNA double-strand breaks (DSBs). This highly toxic lesion triggers a series of DNA damage response reactions, starting with a kinase cascade that phosphorylates a large number of substrates, including the histone H2A.X to lead the early DSB marker γH2A.X. Western blot studies showed that basal expression of γH2A.X was reduced in the presence of 3. Interestingly, the typical increase in γH2A.X levels produced by camptothecin (CPT), a drug that generates DSB, was not observed when CPT was co-administered with 3. These findings suggest that 3 might disrupt Toxoplasma DNA damage response.

Phytochemicals and Potential Therapeutic Targets on Toxoplasma gondii Parasite

Identification of drug target in protozoan T. gondii is an important step in the development of chemotherapeutic agents. Likewise, exploring phytochemical compounds effective against the parasite can lead to the development of new drug agent that can be useful for prophylaxis and treatment of toxoplasmosis. In this review, we searched for the relevant literature on the herbs that were tested against T. gondii either in vitro or in vivo, as well as different phytochemicals and their potential activities on T. gondii. Potential activities of major phytochemicals, such as alkaloid, flavonoid, terpenoids and tannins on various target sites on T. gondii as well as other related parasites was discussed. It is believed that the phytochemicals from natural sources are potential drug candidates for the treatment of toxoplasmosis with little or no toxicity to humans.

N-Methyl-β-carboline alkaloids: structure-dependent photosensitizing properties and localization in subcellular domains

N-Methyl-β-carboline (βC) alkaloids, including normelinonine F (1b) and melinonine F (2b), have been found in a vast range of living species playing different biological, biomedical and/or pharmacological roles. Despite this, molecular bases of the mechanisms through which these alkaloids would exert their effect still remain unknown. Fundamental aspects including the photosensitizing properties and intracellular internalization of a selected group of N-methyl-βC alkaloids were investigated herein. Data reveal that methylation of the βC main ring enhances its photosensitizing properties either by increasing its binding affinity with DNA as a biomolecular target and/or by increasing its oxidation potential, in a structure-dependent manner. As a general rule, N(9)-substituted βCs showed the highest photosensitizing efficiency. With the exception of 2-methyl-harminium, all the N-methyl-βCs investigated herein induce a similar DNA photodamage profile, dominated largely by oxidized purines. This fact represents a distinctive behavior when comparing with N-unsubstituted-βCs. On the other hand, although all the investigated compounds might accumulate mainly into the mitochondria of HeLa cells, methylation provides a distinctive dynamic pattern for mitochondrial uptake. While rapid (passive) diffusion is most probably reponsible for the prompt uptake/release of neutral βCs, an active transport appears to mediate the (reatively slow) uptake of the quaternary cationic βCs. This might be a consequence of a distinctive subcellular localization (mitochondrial membrane and/or matrix) or interaction with intracellular components. Biomedical and biotechnological implications are also discussed herein.

Therapeutic Interventions for Countering Leishmaniasis and Chagas's Disease: From Traditional Sources to Nanotechnological Systems

The incidence of neglected diseases in tropical countries, such as Leishmaniasis and Chagas's disease, is attributed to a set of biological and ecological factors associated with the socioeconomic context of developing countries and with a significant burden to health care systems. Both Leishmaniasis and Chagas's disease are caused by different protozoa and develop diverse symptoms, which depend on the specific species infecting man. Currently available drugs to treat these disorders have limited therapeutic outcomes, frequently due to microorganisms' drug resistance. In recent years, significant efforts have been made towards the development of innovative drug delivery systems aiming to improve bioavailability and pharmacokinetic profiles of classical drug therapy. This paper discusses the key facts of Leishmaniasis and Chagas's disease, the currently available pharmacological therapies and the new drug delivery systems for conventional drugs.

Harmine enhances type H vessel formation and prevents bone loss in ovariectomized mice

Recently, researchers identified a distinct vessel subtype called type H vessels that couple angiogenesis and osteogenesis. We previously found that type H vessels are reduced in ovariectomy (OVX)-induced osteoporotic mice, and preosteoclasts are able to secrete platelet-derived growth factor-BB (PDGF-BB) to stimulate type H vessel formation and thereby to promote osteogenesis. This study aimed to explore whether harmine, a β-carboline alkaloid, is capable of preventing bone loss in OVX mice by promoting preosteoclast PDGF-BB-induced type H vessel formation.

METHODS

The impact of harmine on osteoclastogenesis of RANKL-stimulated RAW264.7 cells was verified by gene expression analysis and tartrate-resistant acid phosphatase (TRAP) staining. Enzyme-linked immunosorbent assay (ELISA) was conducted to test PDGF-BB production by preosteoclasts. A series of angiogenesis-related assays in vitro were performed to assess the pro-angiogenic effects of the conditioned media from RANKL-stimulated RAW264.7 cells treated with or without harmine. Meanwhile, the role of PDGF-BB in this process was determined. In vivo, OVX mice were intragastrically administrated with harmine emulsion or an equal volume of vehicle. 2 months later, bone samples were collected for µCT, histological, immunohistochemical and immunofluorescent analyses to evaluate bone mass, osteogenic and osteoclastic activities, as well as the numbers of type H vessels. Bone marrow PDGF-BB concentrations were assessed by ELISA.

RESULTS

Exposure of RANKL-stimulated RAW264.7 cells to harmine enhanced the formation of preosteoclasts and the production of PDGF-BB. Harmine augmented the ability of RANKL-stimulated RAW264.7 cells to promote angiogenesis of endothelial cells, whereas the effect was blocked by PDGF-BB inhibition. In vivo, the oral administration of harmine emulsion to OVX mice resulted in enhanced trabecular bone mass and osteogenic responses, increased numbers of preosteoclasts, as well as reduced numbers of osteoclasts and fat cells. Moreover, OVX mice treated with harmine exhibited higher levels of bone marrow PDGF-BB and much more type H vessels in bone.

CONCLUSION

Harmine may exert bone-sparing effects by suppression of osteoclast formation and promotion of preosteoclast PDGF-BB-induced angiogenesis.

Andrographolide engineered gold nanoparticle to overcome drug resistant visceral leishmaniasis

Visceral leishmaniasis (VL) is World Health Organization designated most serious leishmaniasis with an annual mortality rate of 50,000. Even after country specific eradication programs, the disease continues to multiply with added complexities like resistance development, drug hypersensitivity and associated infections. Newer therapeutic interventions are urgently warranted to control the spread. Present study aims to arrive at terpenoid andrographolide engineered gold nanoparticle (AGAunps) facile synthesis and its efficacy evaluations against wild and drug resistant VL strains for the first time. Molecular bio-organic conjugation of AGAunp was confirmed in FT-IR and EDAX studies. Nano-gold plasmon response was recorded at 543 nm and the average size in TEM was 14 nm. SAED pattern and XRD observations proved fcc crystalline structure of nano-gold. AGAunp recorded spherical geometry in AFM and TEM. PDI value of 0.137 revealed the monodisperse nature of the nano-scale population. AGAunp exhibited strong antileishmanicidal effect both against wild type (IC₅₀ 19 ± 1.7 µM) and sodium stibogluconate (IC₅₀ 55 ± 7.3 µM)/paromomycin (IC₅₀ 41 ± 6 µM) resistant strains. Complete macrophage uptake AGAunp's occured within two hours exposure. AGAunp macrophage cytotoxicity was significantly lower as compared to Amphotericin-B. Low toxic Andrographolide engineered gold nanoparticle emerged as promising alternatives in the control of wild and drug resistant VL.

Combination of doxorubicin with harmine-loaded liposomes exerting synergistic antitumor efficacy

CONTEXT

Long-circulation (PEGLip), pH-sensitive (PEOzLip), and active targeted liposomes (PEG-TATLip)-loading doxorubicin (DOX) and harmine (HM) were prepared. Their physicochemical properties and antitumor effect were investigated.

OBJECTIVES

The aims of the present study were to evaluate synergistic antitumor efficacy.

MATERIALS AND METHODS

Liposomes were prepared by using thin-film dispersion, active drug-loading and target post-insertion method. Subsequently physiochemical properties including particle size distribution, zeta potential, entrapment efficiency (EE), drug-loading content and in-vitro release were determined. Besides, the in vitro cytotoxicity of free drugs and drug-loaded liposomes was explored by using a Sulforhodamine-B Staining assay and the combination index values (CI Value) were calculated. Finally, the cellular uptake experiments by MCF-7cells were carried out via flow cytometry.

RESULTS AND DISCUSSION

All liposomes enhanced the antitumor effect significantly compared to free drugs. Among liposomes, PEG-TATLip enhanced the antitumor effect significantly compared to others. DOX and HM had moderate synergism with CI Value 0.85 for free drugs, 0.81 for PEGLip, 0.72 for PEOzLip, and 0.84 for PEG-TATLip respectively when the weight ratio of two drugs was 1:2. Moreover, the similarity between DOX and HM such as physicochemical properties, in vitro release modes and in vitro uptake kinetics characteristics when they were in the same formulations proved it possible for them to be delivered together.

CONCLUSION

Active targeting liposomes were the most effective delivery system as compared with pH-sensitive and long circulation liposomes. Additionally, DOX and HM could be co-delivered in liposomes and they could play moderate synergism effect in antitumor efficacy.

Chemical screening identifies the β-Carboline alkaloid harmine to be synergistically lethal with doxorubicin

Despite being an invaluable chemotherapeutic agent for several types of cancer, the clinical utility of doxorubicin is hampered by its age-related and dose-dependent cardiotoxicity. Co-administration of dexrazoxane as a cardioprotective agent has been proposed, however recent studies suggest that it attenuates doxorubicin-induced antitumor activity. Since compounds of natural origin present a rich territory for drug discovery, we set out to identify putative natural compounds with the view to mitigate or minimize doxorubicin cardiotoxicity. We identify the DYRK1A kinase inhibitor harmine, which phosphorylates Tau that is deregulated in Alzheimer's disease, as a potentiator of cell death induced by non-toxic doses of doxorubicin. These observations suggest that harmine or other compounds that target the DYRK1A kinase my offer a new therapeutic opportunity to suppress doxorubicin age-related and dose-dependent cardiotoxicity.

The Role of Natural Products in Drug Discovery and Development against Neglected Tropical Diseases

Endemic in 149 tropical and subtropical countries, neglected tropical diseases (NTDs) affect more than 1 billion people annually, including 875 million children in developing economies. These diseases are also responsible for over 500,000 deaths per year and are characterized by long-term disability and severe pain. The impact of the combined NTDs closely rivals that of malaria and tuberculosis. Current treatment options are associated with various limitations including widespread drug resistance, severe adverse effects, lengthy treatment duration, unfavorable toxicity profiles, and complicated drug administration procedures. Natural products have been a valuable source of drug regimens that form the cornerstone of modern pharmaceutical care. In this review, we highlight the potential that remains untapped in natural products as drug leads for NTDs. We cover natural products from plant, marine, and microbial sources including natural-product-inspired semi-synthetic derivatives which have been evaluated against the various causative agents of NTDs. Our coverage is limited to four major NTDs which include human African trypanosomiasis (sleeping sickness), leishmaniasis, schistosomiasis and lymphatic filariasis.

Differential gene expression of salt-stressed Peganum harmala L

The response of Peganum harmala L. seedlings subjected to salinity was investigated through the observation of germination at the 4th, 6th and 8th days under normal and two salinity levels (150 and 200 mM NaCl). Genetic response of P. harmala was examined by quantitative estimation and electrophoretic separation of catalase and salt-soluble proteins. The gene expression of catalase and osmotin were investigated using RT-PCR. Final percentage of germination at the eighth day of germination was reduced from 85% in the control to 70 and 30% under the concentration of 150 and 200 mM. The catalase activity and protein content increased as the salinity increased compared to control seedlings. The electrophoretic separation of catalase and salt-soluble proteins exhibited stress-related isozymes and protein bands. RT-PCR of cat1, cat2-3 and cat3 and osmotin genes exhibited up-regulation and down-regulation of genes subsequent to salinity. The reduced germination percentage of salt stressed seedlings was attributed to oxidative damage and osmotic imbalance. The increased catalase activity and protein content were concluded as protective response of P. harmala seedlings to salinity induced oxidative stress and osmoregulation. The additional isozyme bands in the salt-stressed seedlings indicated modulation of CAT gene expression in response to elevated H2O2 subsequent to salinity. The stress specific gene expression was interpreted as molecular mechanism by which plants can tolerate salinity stress. The up-regulation of cat2-3 gene in relation to stress suggests it crucial role in salinity tolerance in P. harmala and further studies are needed for its sequence identification.

16-hydroxy-cleroda-3,13-dien-16,15-olide induced glioma cell autophagy via ROS generation and activation of p38 MAPK and ERK-1/2

16-hydroxy-cleroda-3,13-dien-16,15-olide (HCD), a natural product isolated from medicinal plant Polyalthia longifolia exhibits anticancer activity through caspase-independent apoptosis in brain tumors, as previously reported. This study further attempted to investigate the involvement of HCD-induced autophagy in brain tumor cell lines neuroblastoma N18 and glioma C6 through the induction of reactive oxygen species (ROS) and the activation of p38 and ERK-1/2 pathway. The results demonstrated that HCD increased the hyper-generation of ROS and decreased cellular antioxidant enzymes, such as superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and glutathione s transferase (GST). Furthermore, HCD increased the expressions of autophagic marker proteins LC3-II and Beclin-1 in a time- and dose-dependent manner. Additionally, HCD was found to significantly induce p-p38 MAPK and p-ERK-1/2 proteins by Western blot, which implies that HCD is a potential therapeutic anticancer agent that exerts its activity through inducing ROS-mediation for the autophagy of brain tumor cells.

A focal adhesion kinase inhibitor 16-hydroxy-cleroda-3,13-dien-16,15-olide incorporated into enteric-coated nanoparticles for controlled anti-glioma drug delivery

16-Hydroxy-cleroda-3,13-dien-16,15-olide (HCD) which is extracted from a medicinal plant, Polyalthia longifolia, was shown to exhibit anticancer activity through apoptosis and FAK inhibition in our previous study. To improve its solubility and efficacy, a novel HCD delivery system using copper-substituted mesoporous silica nanoparticles (MSNs) was designed as a delivery vehicle, and the outer surfaces of MSNs were further coated with enteric polymers to prevent the drug from leaching in the stomach acid. All the data regarding synthesis and physical characterization, including Zeta potential, FT-IR spectra, N2 adsorption-desorption isotherms (BET), drug loading, powder X-ray diffraction, Thermo gravimetric analysis (TGA), Transmission electron microscopy (TEM), and Scanning electron microscopy (SEM) were well characterized. The non-coated MSN-HCD exposed to acidic pH (1.2) showed a rapid degradation of the drug, whereas the enteric-coated samples presented a sustained release profile in the gastrointestinal pHs. Cell cytotoxicity was further confirmed by the MTT-C6 Glioma cell line, in vitro. When compared with the control and pure HCD, the MSN-HCD revealed a potential anti-proliferation effect via the synergistic effect of the drug and the MSN vehicle. Additionally, this MSN-HCD had the effect of increasing the reactive oxygen species (ROS) levels and altered the Mitochondria membrane potential (MMP) in C6 cell line. The in vivo anti-tumor efficacy of enteric-coated MSN-HCD was evaluated by C6 Glioma bearing xenograft nude mice, and enteric-coated MSN-HCD clearly exhibited the greatest anti-glioma activity, as compared to the pure HCD and the untreated control. In terms of the effective treatment of brain glioma, this study provides conclusive evidence of the successful development of the anti-cancer agent HCD conjugated with enteric-coated MSN as a delivery control mechanism with enhanced dissolution characteristics.

A review on medicinal importance, pharmacological activity and bioanalytical aspects of beta-carboline alkaloid ''Harmine''

Harmine, a beta-carboline alkaloid, is widely distributed in the plants, marine creatures, insects, mammalians as well as in human tissues and body fluids. Harmine was originally isolated from seeds of Peganum harmal in 1847 having a core indole structure and a pyridine ring. Harmine has various types of pharmacological activities such as antimicrobial, antifungal, antitumor, cytotoxic, antiplasmodial, antioxidaant, antimutagenic, antigenotoxic and hallucinogenic properties. It acts on gamma-aminobutyric acid type A and monoamine oxidase A or B receptor, enhances insulin sensitivity and also produces vasorelaxant effect. Harmine prevents bone loss by suppressing osteoclastogenesis. The current review gives an overview on pharmacological activity and analytical techniques of harmine, which may be useful for researcheres to explore the hidden potential of harmine and and will also help in developing new drugs for the treatment of various diseases.

Novel β-carboline–quinazolinone hybrid as an inhibitor of Leishmania donovani trypanothione reductase: Synthesis, molecular docking and bioevaluation

Novel β-carboline–quinazolinone hybrids are able to inhibit Leishmania donovani TR (LdTR). Molecular docking studies to investigate possible binding sites were performed.

Peganum harmala Aqueous and Ethanol Extracts Effects on Lesions Caused by Leishmania major (MRHO/IR/75/ER) in BALB/c Mice

BACKGROUND

Leishmaniasis is one of the six most common parasitic infections in the tropical regions. There are different therapeutic modalities, however therapeutic resistance is developed and resulted in numerous problems. Therefore, evaluation of other therapeutic modalities is performed extensively.

OBJECTIVES

The current study aimed to compare the therapeutic response of cutaneous leishmaniasis with Glucantime and Peganum harmala extracts (aqueous and ethanol) in the animal model.

MATERIALS AND METHODS

The therapeutic response of Leishmania major to Glucantime and P. harmala extracts (aqueous and ethanol) in animal model was studied in BALB/c mice. These mice were divided into four groups according to receiving either one of these three agents, and the control group. The therapeutic response was evaluated according to the parasitic load before and after treatment and also with measuring the size of the lesions.

RESULTS

The results showed that ethanol extract of P. harmala had good therapeutic efficacy in treatment of lesions in mice (P < 0.05), and the efficacy was significant in the eighth week after the treatment. There was also a statistically significant difference between the groups regarding the parasitic load (P < 0.05).

CONCLUSIONS

According to the current study results, it may be concluded that ethanol extract of P. harmala is efficient in the treatment of cutaneous leishmaniasis, and the efficiency is comparable with that of Glucantime.

Liposomal formulation of turmerone-rich hexane fractions from Curcuma longa enhances their antileishmanial activity

Promastigote forms of Leishmania amazonensis were treated with different concentrations of two fractions of Curcuma longa cortex rich in turmerones and their respective liposomal formulations in order to evaluate growth inhibition and the minimal inhibitory concentration (MIC). In addition, cellular alterations of treated promastigotes were investigated under transmission and scanning electron microscopies. LipoRHIC and LipoRHIWC presented lower MIC, 5.5 and 12.5 μg/mL, when compared to nonencapsulated fractions (125 and 250 μg/mL), respectively, and to ar-turmerone (50 μg/mL). Parasite growth inhibition was demonstrated to be dose-dependent. Important morphological changes as rounded body and presence of several roles on plasmatic membrane could be seen on L. amazonensis promastigotes after treatment with subinhibitory concentration (2.75 μg/mL) of the most active LipoRHIC. In that sense, the hexane fraction from the turmeric cortex of Curcuma longa incorporated in liposomal formulation (LipoRHIC) could represent good strategy for the development of new antileishmanial agent.

Transdermal delivery of meloxicam using niosomal hydrogels: in vitro and pharmacodynamic evaluation

Non-ionic surfactant vesicles were prepared using Span-60 and cholesterol in the mass ratios of 1:1, 2:1, 1:2 and 3:1 for transdermal delivery of an anti-inflammatory drug meloxicam (MXM). The drug encapsulation efficiencies and particle size were observed in the range of 32.9-80.7% and 56.5-133.4 nm, respectively. Three different gel bases were also prepared using Poloxamer-407, Chitosan and Carbopol-934 as polymers to study the performance of the in vitro release of the drug. Prepared gels were also converted into niosomal gels. In vitro release characteristics of MXM from different gels were carried out using dialysis membrane in phosphate buffer (pH 7.4). The poloxamer-407 gel or niosomal poloxamer-407 gel showed the superior drug release over the other formulations. The release data were treated with various mathematical models to assess the relevant parameters. The results showed that the release of MXM from the prepared gels and niosomal gels followed Higuchi's diffusion model. The flux of MXM was found to be independent on the viscosity of the formulations. The anti-inflammatory effects of MXM from different niosomal gel formulations were evaluated using carrageenan-induced rat paw edema method, which showed superiority of niosomal gels over conventional gels.

Nonionic surfactant vesicles in ocular delivery: innovative approaches and perspectives

With the recent advancement in the field of ocular therapy, drug delivery approaches have been elevated to a new concept in terms of nonionic surfactant vesicles (NSVs), that is, the ability to deliver the therapeutic agent to a patient in a staggered profile. However the major drawbacks of the conventional drug delivery system like lacking of permeability through ocular barrier and poor bioavailability of water soluble drugs have been overcome by the emergence of NSVs. The drug loaded NSVs (DNSVs) can be fabricated by simple and cost-effective techniques with improved physical stability and enhance bioavailability without blurring the vision. The increasing research interest surrounding this delivery system has widened the areas of pharmaceutics in particular with many more subdisciplines expected to coexist in the near future. This review gives a comprehensive emphasis on NSVs considerations, formulation approaches, physicochemical properties, fabrication techniques, and therapeutic significances of NSVs in the field of ocular delivery and also addresses the future development of modified NSVs.

Antiparasitic effect of wild rue (Peganum harmala L.) against experimentally induced coccidiosis in broiler chicks

Organic farming of poultry has increased in recent years as the prophylactic use of antibiotics has come into disfavor. This study was conducted to explore the antiparasitic effect of a methanolic extract of Peganum harmala in broilers challenged with coccidiosis. For this purpose, 200 1-week-old broiler chicks were divided into five treatments: negative control (basal diet, Ph-0/NC), positive control (basal diet with coccidiosis challenge, Ph-0/C), and three groups challenged with coccidiosis and supplemented with P. harmala at the rate of 200 mg L(-1) (Ph-200), 250 mg L(-1) (Ph-250), and 300 mg L(-1) (Ph-300) drinking water. Each group had three replicates of ten chicks each. Challenge with standard dose of the larvae of coccidiosis and supplementation of P. harmala were initiated on day 14 until 35 days of age. As expected, the results revealed that weight gain, feed intake, and feed conversion ratio (FCR) were depressed significantly in Ph-0 group with significant mortality percentage. Weight gain, total body weight, and FCR increased linearly with increasing dose of P. harmala with the exception of feed intake. The growth and feed efficiency of Ph-0/NC was better in Ph-0/NC compared to that in Ph-0/C and comparable to that in P. harmala-treated birds. Similarly, mean ooccytes per gram (OPG) decreased linearly (P < 0.05) in supplemented groups compared to that in Ph-0/C. Histological evidences showed that cecal lesion and leucocyte infiltration decreased markedly in supplemented groups of P. harmala specifically the Ph-300 group compared to those in Ph-0/C. From the present experiment, we concluded the anticoccidial effect of P. harmala in broiler chicks.

Novel self-assembled micelles based on palmitoyl-trimethyl-chitosan for efficient delivery of harmine to liver cancer

BACKGROUND

Polymeric micelles is a safe and effective delivery system, which belong to the targeted delivery system (TDS). An anticancer drug, harmine(HM) is a hydrophobic drug with much adverse effects when used for treatment of liver cancer. Chitosan (CS) is a polysaccharide and can be modified to be an amphiphilic polmer which could self-assemble into micelles and be applied for delivery of hydrophobic drugs.

OBJECTIVES

To synthesize three kinds of novel biodegradable polymers, designated as palmitoyl-trimethyl-CS (TPCS)1, TPCS2 and Lac-TPCS2, and investigate their efficiency and mechanism of delivery HM to liver tumors in vitro and in viro.

RESULTS

The self-assembled micelles presented satisfactory particle size (∼ 200 nm) and drug release characteristics in vitro. It's proved that Lac-TPCS2/HM may enter HepG2 cell through endocytosis. Antitumor experiments in vivo revealed that Lac-TPCS2/HM could significantly inhibit tumor growth and extend the lifetime of mice bearing H22 tumors after intravenous administration. Subsequently in vivo near-infrared fluorescence imaging results demonstrated a satisfactory liver tumor-targeting effect of Lac-TPCS2/HM.

CONCLUSION

Three novel polymers hold great potential in the development of nanomedicine for treatment of liver tumors, in particular Lac-TPCS2 exhibits the greatest antitumor potential through active target effect.

Polymeric colloidal particulate systems: intelligent tools for intracellular targeting of antileishmanial cargos

INTRODUCTION

Targeted cargo delivery systems can overcome drawbacks associated with antileishmanials delivery, by defeating challenges of physiological barriers. Various colloidal particulate systems have been developed in the past; few of them even achieved success in the market, but still are limited in some ways.

AREAS COVERED

This review is focused on the pathobiology of leishmaniasis, interactions of particulate systems with biological environment, targeting strategies along with current conventional and vaccine therapies with special emphasis on polymeric nanotechnology for effective antileishmanial cargo delivery.

EXPERT OPINION

The problems concerned with limited accessibility of chemotherapeutic cargos in conventional modes to Leishmania-harboring macrophages, their toxicity, and resistant parasitic strain development can be sorted out through target-specific delivery of cargos. Vaccination is another therapeutic approach employing antigen alone or adjuvant combinations delivered by means of a carrier, and can provide preventive measures against human leishmaniasis (HL). Therefore, there is an urgent need of designing site-specific antileishmanial cargo carriers for safe and effective management of HL. Among various colloidal carriers, polymeric particulate systems hold tremendous potential as an effective delivery tool by providing control over spatial and temporal distribution of cargos after systemic or localized administration along with enhancing their stability profile at a comparatively cost-effective price leading to improved chances of commercial applicability.

Drug resistance in leishmaniasis: current drug-delivery systems and future perspectives

Leishmaniasis is a complex of diseases with numerous clinical manifestations for instance harshness from skin lesions to severe disfigurement and chronic systemic infection in the liver and spleen. So far, the most classical leishmaniasis therapy, despite its documented toxicities, remains pentavalent antimonial compounds. The arvailable therapeutic modalities for leishmaniasis are overwhelmed with resistance to leishmaniasis therapy. Mechanisms of classical drug resistance are often related with the lower drug uptake, increased efflux, the faster drug metabolism, drug target modifications and over-expression of drug transporters. The high prevalence of leishmaniasis and the appearance of resistance to classical drugs reveal the demand to develop and explore novel, less toxic, low cost and more promising therapeutic modalities. The review describes the mechanisms of classical drug resistance and potential drug targets in Leishmania infection. Moreover, current drug-delivery systems and future perspectives towards Leishmaniasis treatment are also covered.

Strategies for the design of orally bioavailable antileishmanial treatments

Leishmaniasis is one of the six major tropical diseases targeted by the World Health Organization. The most serious, life-threatening form is visceral leishmaniasis (VL). No vaccine is yet available for human use and chemotherapy is the main mean of dealing with this disease. This review focuses on the development of drug delivery systems (DDS) for treatment of leishmaniasis. After an overview of the significance of leishmaniasis in 2013, current chemotherapy and its limitations are considered, leading to possible strategies to improve the treatment of VL: new drugs, combinations of existing drugs and DDS, particularly for oral administration. Nanostructured biomaterials such as lipid-based or polymeric nanoparticles have unique physicochemical properties, ultra-small and controllable size, large surface area to mass ratio and the possibility of surface modification which can be used to advantage for the oral administration of antileishmanial drugs. They can improve the rate of dissolution of poorly water-soluble drugs, increase intestinal residence time by bioadhesion and, especially when lipid additives are used, influence the route and efficiency of absorption. These recent advances in this very active field should lead to better management of this serious disease.

In vitro evaluation of β-carboline alkaloids as potential anti-Toxoplasma agents

Background

Toxoplasmosis is a worldwide infection caused by the protozoan parasite Toxoplasma gondii, which causes chorioretinitis and neurological defects in congenitally infected newborns or immunodeficient patients. The efficacy of the current treatment is limited, primarily by serious host toxicity. In recent years, research has focused on the development of new drugs against T. gondii. β-Carbolines (βCs), such as harmane, norharmane and harmine, are a group of naturally occurring alkaloids that show microbicidal activity. In this work, harmane, norharmane and harmine were tested against T. gondii.

Findings

The treatment of extracellular tachyzoites with harmane, norharmane and harmine showed a 2.5 to 3.5-fold decrease in the invasion rates at doses of 40 μM (harmane and harmine) and 2.5 μM (norharmane) compared with the untreated parasites. Furthermore, an effect on the replication rate could also be observed with a decrease of 1 (harmane) and 2 (norharmane and harmine) division rounds at doses of 5 to 12.5 μM. In addition, the treated parasites presented either delayed or no monolayer lysis compared with the untreated parasites.

Conclusions

The three βC alkaloids studied (norharmane, harmane and harmine) exhibit anti-T. gondii effects as evidenced by the partial inhibition of parasite invasion and replication. A dose–response effect was observed at a relatively low drug concentration (< 40 μM), at which no cytotoxic effect was observed on the host cell line (Vero).

Application of the central composite design to optimize the preparation of novel micelles of harmine

Lactose–palmitoyl–trimethyl–chitosan (Lac-TPCS), a novel amphipathic self-assembled polymer, was synthesized for administration of insoluble drugs to reduce their adverse effects. The central composite design was used to study the preparation technique of harmine (HM)-loaded self-assembled micelles based on Lac-TPCS (Lac-TPCS/HM). Three preparation methods and single factors were screened, including solvent type, HM amount, hydration volume, and temperature. The optimal preparation technique was identified after investigating the influence of two independent factors, namely, HM amount and hydration volume, on four indexes, ie, encapsulation efficiency (EE), drug-loading amount (LD), particle size, and polydispersity index (PDI). Analysis of variance showed a high coefficient of determination of 0.916 to 0.994, thus ensuring a satisfactory adjustment of the predicted prescription. The maximum predicted values of the optimal prescription were 91.62%, 14.20%, 183.3 nm, and 0.214 for EE, LD, size, and PDI, respectively, when HM amount was 1.8 mg and hydration volume was 9.6 mL. HM-loaded micelles were successfully characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and a fluorescence-quenching experiment. Sustained release of Lac-TPCS/HM reached 65.3% in 72 hours at pH 7.4, while free HM released about 99.7% under the same conditions.

A natural small molecule harmine inhibits angiogenesis and suppresses tumour growth through activation of p53 in endothelial cells

Activation of p53 effectively inhibits tumor angiogenesis that is necessary for tumor growth and metastasis. Reactivation of the p53 by small molecules has emerged as a promising new strategy for cancer therapy. Several classes of small-molecules that activate the p53 pathway have been discovered using various approaches. Here, we identified harmine (β-carboline alkaloid) as a novel activator of p53 signaling involved in inhibition of angiogenesis and tumor growth. Harmine induced p53 phosphorylation and disrupted the p53-MDM2 interaction. Harmine also prevented p53 degradation in the presence of cycloheximide and activated nuclear accumulation of p53 followed by increasing its transcriptional activity in endothelial cells. Moreover, harmine not only induced endothelial cell cycle arrest and apoptosis, but also suppressed endothelial cell migration and tube formation as well as induction of neovascularity in a mouse corneal micropocket assay. Finally, harmine inhibited tumor growth by reducing tumor angiogenesis, as demonstrated by a xenograft tumor model. Our results suggested a novel mechanism and bioactivity of harmine, which inhibited tumor growth by activating the p53 signaling pathway and blocking angiogenesis in endothelial cells.

Niosomes as a propitious carrier for topical drug delivery

INTRODUCTION

Topical delivery is defined as drug targeting to the pathologic sites of skin with the least systemic absorption. Drug localization in this case is a crucial issue. For these purposes vesicular drug delivery systems including niosomes, proniosomes, liposomes and transferosomes have been developed.

AREAS COVERED

This review first highlights the role of niosome in dermatology focusing on localized skin delivery and then reviews the most recent literatures regarding specific applications of niosomal drug delivery systems in clinics.

EXPERT OPINION

Niosomes are becoming popular in the field of topical drug delivery due to their outstanding characteristics like enhancing the penetration of drugs, providing a sustained pattern of drug release, increasing drug stability and ability to carry both hydrophilic and lipophilic drugs.

Byrsonima fagifolia Niedenzu Apolar Compounds with Antitubercular Activity

Bioassay-guided fractionation of the chloroform extract of Byrsonima fagifolia leaves led to the isolation of active antitubercular compounds alkane dotriacontane (Minimal Inhibitory Concentration—MIC, 62.5 μg mL⁻¹), triterpenoids as bassic acid (MIC = 2.5 μg mL⁻¹), α-amyrin acetate (MIC = 62.5 μg mL⁻¹), a mixture of lupeol, α- and β-amyrin (MIC = 31.5 μg mL⁻¹) and a mixture of lupeol, and acetates of α- and β-amyrin (MIC = 31.5 μg mL⁻¹). The antimycobacterial activity was determined by the Microplate Alamar Blue Assay (MABA) and the structures of promising compounds were determined by spectroscopic analysis. This investigation constitutes the first report of a chemical and antitubercular study of apolar compounds from B. fagifolia Niedenzu (IK).

Identification of small molecule lead compounds for visceral leishmaniasis using a novel ex vivo splenic explant model system

BACKGROUND

New drugs are needed to treat visceral leishmaniasis (VL) because the current therapies are toxic, expensive, and parasite resistance may weaken drug efficacy. We established a novel ex vivo splenic explant culture system from hamsters infected with luciferase-transfected Leishmania donovani to screen chemical compounds for anti-leishmanial activity.

METHODOLOGY/PRINCIPAL FINDINGS

THIS MODEL HAS ADVANTAGES OVER IN VITRO SYSTEMS IN THAT IT: 1) includes the whole cellular population involved in the host-parasite interaction; 2) is initiated at a stage of infection when the immunosuppressive mechanisms that lead to progressive VL are evident; 3) involves the intracellular form of Leishmania; 4) supports parasite replication that can be easily quantified by detection of parasite-expressed luciferase; 5) is adaptable to a high-throughput screening format; and 6) can be used to identify compounds that have both direct and indirect anti-parasitic activity. The assay showed excellent discrimination between positive (amphotericin B) and negative (vehicle) controls with a Z' Factor >0.8. A duplicate screen of 4 chemical libraries containing 4,035 compounds identified 202 hits (5.0%) with a Z score of <-1.96 (p<0.05). Eighty-four (2.1%) of the hits were classified as lead compounds based on the in vitro therapeutic index (ratio of the compound concentration causing 50% cytotoxicity in the HepG(2) cell line to the concentration that caused 50% reduction in the parasite load). Sixty-nine (82%) of the lead compounds were previously unknown to have anti-leishmanial activity. The most frequently identified lead compounds were classified as quinoline-containing compounds (14%), alkaloids (10%), aromatics (11%), terpenes (8%), phenothiazines (7%) and furans (5%).

CONCLUSIONS/SIGNIFICANCE

The ex vivo splenic explant model provides a powerful approach to identify new compounds active against L. donovani within the pathophysiologic environment of the infected spleen. Further in vivo evaluation and chemical optimization of these lead compounds may generate new candidates for preclinical studies of treatment for VL.

Andrographolide nanoparticles in leishmaniasis: characterization and in vitro evaluations

Andrographolide (AG) is a diterpenoid lactone isolated from the leaves of Andrographis paniculata. AG is a potent and low-toxicity antileishmanial agent. Chemotherapy applications of AG are, however, seriously constrained because of poor bioavailability, short plasma half-life, and inappropriate tissue localization. Nanoparticulation of AG was therefore envisaged as a possible solution. AG nanoparticles (AGnp) loaded in 50:50 poly(DL-lactide-co-glycolic acid) were prepared for delivery into the monocyte–macrophage cells infested with the amastigote form of leishmanial parasite for evaluation in the chemotherapy of leishmaniasis. Particle characteristics of AGnp were optimized by proportionate application of a stabilizer, polyvinyl alcohol (PVA). Physicochemical characterization of AGnp by photon correlation spectroscopy exhibited an average particle size of 173 nm and zeta potential of −34.8 mV. Atomic force microscopy visualization revealed spherical nanoparticles with a smooth surface. Antileishmanial activity was found to be significant for the nanoparticle preparation with 4% PVA (IC₅₀ 34 μM) in about one-fourth of the dosage of the pure compound AG (IC₅₀ 160 μM). AGnp therefore have significant potential to target the infested macrophage cells and prove valuable in chemotherapy of neglected tropical diseases such as leishmaniasis.