Cardamonin, a schistosomicidal chalcone from Piper aduncum L. (Piperaceae) that inhibits Schistosoma mansoni ATP diphosphohydrolase

Evaluation of metformin's effect on the adult and juvenile stages of Schistosoma mansoni: an in-vitro study

Metformin (Met), a well-known anti-diabetic drug with a potent autophagy induction property, has been proven to be effective against several parasitic diseases. In the present in vitro study, the effect of Met on the viability and ultrastructure of Schistosoma mansoni adults and juveniles in comparison with the standard anti-schistosomal drug, praziquantel (PZQ), was investigated. Adults and juveniles were treated in vitro with 5 µM PZQ and/or 10 mM Met. The viability of the treated worms was screened over a three-day period by light microscopy and recorded as mortality rates (MR). The alterations in the ultrastructure were verified using scanning and transmission electron microscopy. Met showed significant anti-schistosomal activity against both adults and juveniles and resulted in severe tegumental damage in the form of loss of integrity and architecture, with evident vacuolation suggestive of increased autophagy. Met might be a potential drug either alone or as an adjuvant to PZQ for the treatment of schistosomiasis mansoni and warrant its further assessment in animal models of disease.

In vivo efficacy of uvangoletin from Piper aduncum (Piperaceae) against Schistosoma mansoni and in silico studies targeting SmNTPDases

Schistosomiasis stands as one of the most significant parasitic diseases on a global scale, with approximately 250 million infections worldwide. It is imperative to address this pressing issue by developing new antischistosomal drugs. Chalcones have emerged as a promising class of natural compounds, demonstrating noteworthy effects observed in vitro experiments with Schistosoma mansoni, and demonstrating the ability to inhibit SmNTPDases and apyrase from potatoes. In this study, we focused on uvangoletin, a naturally occurring dihydrochalcone from Piper aduncum. We isolated uvangoletin from P. aduncum fruits and conducted in vivo experiments to evaluate the efficacy of uvangoletin against adult Schistosoma parasites. Furthermore, we explored the inhibitory effects of uvangoletin on potato apyrase and employed molecular docking analyses to investigate its interactions with apyrase from potato and the two isoforms SmNTPDase 1 and 2 through in silico studies. Uvangoletin (400 mg/kg, p. o.), exhibited significant in vivo antiparasitic effects against adult S. mansoni, leading to a decrease of 53.7% in worm burden and 54.3% in egg production. The treatment also reduced hepatomegaly and splenomegaly. In silico investigations and ADMET studies indicated that uvangoletin possesses favorable drug-like properties and may interact with key residues involved in apyrase and SmNTPDases activities. Furthermore, uvangoletin demonstrated a substantial reduction in potato apyrase activity. These results suggest the potential for exploring other dihydrochalcones as promising candidates for antischistosomal agents.

Regulation of Flavonoid Biosynthesis by the MYB-bHLH-WDR (MBW) Complex in Plants and Its Specific Features in Cereals

Flavonoids are a large group of secondary metabolites, which are responsible for pigmentation, signaling, protection from unfavorable environmental conditions, and other important functions, as well as providing numerous benefits for human health. Various stages of flavonoid biosynthesis are subject to complex regulation by three groups of transcription regulators-MYC-like bHLH, R2R3-MYB and WDR which form the MBW regulatory complex. We attempt to cover the main aspects of this intriguing regulatory system in plants, as well as to summarize information on their distinctive features in cereals. Published data revealed the following perspectives for further research: (1) In cereals, a large number of paralogs of MYC and MYB transcription factors are present, and their diversification has led to spatial and biochemical specialization, providing an opportunity to fine-tune the distribution and composition of flavonoid compounds; (2) Regulatory systems formed by MBW proteins in cereals possess distinctive features that are not yet fully understood and require further investigation; (3) Non-classical MB-EMSY-like complexes, WDR-independent MB complexes, and solely acting R2R3-MYB transcription factors are of particular interest for studying unique regulatory mechanisms in plants. More comprehensive understanding of flavonoid biosynthesis regulation will allow us to develop cereal varieties with the required flavonoid content and spatial distribution.

Antiparasitic properties of 4-nerolidylcatechol from Pothomorphe umbellata (L.) Miq. (Piperaceae) in vitro and in mice models with either prepatent or patent Schistosoma mansoni infections

ETHNOPHARMACOLOGICAL RELEVANCE

Roots of Pothomorphe umbellata (L.) Miq. are used in traditional medicine of Africa and South America for the treatment of malaria and helminthiasis. However, neither P. umbellata nor its isolated compounds have been evaluated against Schistosoma species.

AIMS OF THIS STUDY

To investigate the antischistosomal effects of P. umbellata root extracts and the isolated compound 4-nerolidylcatechol (4-NC) against Schistosoma mansoni ex vivo and in murine models of schistosomiasis.

MATERIALS AND METHODS

The crude hydroalcoholic (PuE) and hexane (PuH) extracts of P. umbellata roots were prepared and initially submitted to an ex vivo phenotypic screening against adult S. mansoni. PuH was analyzed by HPLC-DAD, characterized by UHPLC-HRMS/MS, and submitted to chromatographic fractionation, leading to the isolation of 4-NC. The anthelmintic properties of 4-NC were assayed ex vivo against adult schistosomes and in murine models of schistosomiasis for both patent and prepatent S. mansoni infections. Praziquantel (PZQ) was used as a reference compound.

RESULTS

PuE (EC₅₀: 18.7 μg/mL) and PuH (EC₅₀: 9.2 μg/mL) kill adult schistosomes ex vivo. The UHPLC-HRMS/MS analysis of PuH, the most active extract, revealed the presence of 4-NC, peltatol A, and peltatol B or C. After isolation from PuH, 4-NC presented remarkable in vitro schistosomicidal activity with EC₅₀ of 2.9 μM (0.91 μg/mL) and a selectivity index higher than 68 against Vero mammalian cells, without affecting viability of nematode Caenorhabditis elegans. In patent S. mansoni infection, the oral treatment with 4-NC decreased worm burden and egg production in 52.1% and 52.3%, respectively, also reducing splenomegaly and hepatomegaly. 4-NC, unlike PZQ, showed in vivo efficacy against juvenile S. mansoni, decreasing worm burden in 52.4%.

CONCLUSIONS

This study demonstrates that P. umbellata roots possess antischistosomal activity, giving support for the medicinal use of this plant against parasites. 4-NC was identified from P. umbellata roots as one of the effective in vitro and in vivo antischistosomal compound and as a potential lead for the development of novel anthelmintics.

Structure-based virtual screening of novel natural products as chalcone derivatives against SARS-CoV-2 Mpro

Coronavirus disease 2019 (COVID-19), which is caused by SARS-CoV-2, has spread quickly around the world, causing a global pandemic. It has infected more than 500 million people as of April 28, 2022. Much research has been reported to stop the virus from spreading, but there are currently no approved medicines to treat COVID-19. In this work, a dataset of 142 natural products collected from various medicinal plants was used to perform structure-based virtual screening (SBVS) through the combined application of molecular docking and molecular dynamics (MD) simulation methods. First, the dataset of compounds was optimized using the density functional theory (DFT) approach. The optimized compounds were then submitted to the first screening, which was done by the pKCM web server to look for drug-likeness and the PyRx to look for binding affinity. Among the 142 natural substances, 10 compounds were selected for docking validation. Compounds that interact with CYS145 and LEU141, the essential catalytic residues, as well as compounds with binding affinities less than -8.0 kcal/mol, are considered promising anti-SARS-CoV-2 drug candidates. The top-ranked compounds were then evaluated by MD simulations and MM-GBSA method. These results could help researchers come up with new natural compounds that could be used to treat SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Current advances on the therapeutic potential of pinocembrin: An updated review

Pinocembrin (5,7-dihydroxyflavone) is a major flavonoid found in many plants, fungi and hive products, mainly honey and propolis. Several in vitro and preclinical studies revealed numerous pharmacological activities of pinocembrin including antioxidant, anti-inflammatory, antimicrobial, neuroprotective, cardioprotective and anticancer activities. Here, we comprehensively review and critically analyze the studies carried out on pinocembrin. We also discuss its potential mechanisms of action, bioavailability, toxicity, and clinical investigations. The wide therapeutic window of pinocembrin makes it a promising drug candidate for many clinical applications. We recommend some future perspectives to improve its pharmacokinetic and pharmacodynamic properties for better delivery that may also lead to new therapeutic advances.

In Vivo Safety and Efficacy of Chalcone-Loaded Microparticles with Modified Polymeric Matrix against Cutaneous Leishmaniasis

Current chemotherapy of cutaneous leishmaniasis (CL) is based on repeated systemic or intralesional administration of drugs that often cause severe toxicity. Previously, we demonstrated the therapeutic potential of biodegradable poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) loaded with 8% of the nitrochalcone CH8 (CH8/PLGA) prepared by a conventional bench method. Aiming at an industrially scalable process and increased drug loading, new MPs were prepared by spray drying: CH8/PDE with PLGA matrix and CH8/PVDE with PLGA + polyvinylpyrrolidone (PVP) matrix, both with narrower size distribution and higher drug loading (18%) than CH8/PLGA. Animal studies were conducted to evaluate their clinical feasibility. Both MP types induced transient local swelling and inflammation, peaking at 1−2 days, following a single intralesional injection. Different from CH8/PDE that released 90% of the drug in the ear tissue in 60 days, CH8/PVDE achieved that in 30 days. The therapeutic efficacy of a single intralesional injection was evaluated in BALB/c mice infected with Leishmania (Leishmania) amazonensis and golden hamsters infected with L. (Viannia) braziliensis. CH8/PVDE promoted greater reduction in parasite burden than CH8/PDE or CH8/PLGA, measured at one month and two months after the treatment. Thus, addition of PVP to PLGA MP matrix accelerates drug release in vivo and increases its therapeutic effect against CL.

Neolignans isolated from Saururus cernuus L. (Saururaceae) exhibit efficacy against Schistosoma mansoni

Schistosomiasis, a parasitic disease caused by the blood fluke of the genus Schistosoma, affects over 230 million people, especially in developing countries. Despite the significant economic and public health consequences, only one drug is currently available for treatment of schistosomiasis, praziquantel. Thus, there is an urgent demand for new anthelmintic agents. Based on our continuous studies involving the chemical prospection of floristic biodiversity aiming to discover new bioactive compounds, this work reports the in vitro antiparasitic activity against Schistosoma mansoni adult worms of neolignans threo-austrobailignan-6 and verrucosin, both isolated from Saururus cernuus L. (Saururaceae). These neolignans showed a significant in vitro schistosomicidal activity, with EC50 values of 12.6-28.1 µM. Further analysis revealed a pronounced reduction in the number of S. mansoni eggs. Scanning electron microscopy analysis revealed morphological alterations when schistosomes were exposed to either threo-austrobailignan-6 or verrucosin. These relevant antischistosomal properties were accompanied by low cytotoxicity potential against the animal (Vero) and human (HaCaT) cell lines, resulting in a high selectivity index. Considering the promising chemical and biological properties of threo-austrobailignan-6 and verrucosin, this research should be of interest to those in the area of neglected diseases and in particular antischistosomal drug discovery.

E-NTPDases: Possible Roles on Host-Parasite Interactions and Therapeutic Opportunities

Belonging to the GDA1/CD39 protein superfamily, nucleoside triphosphate diphosphohydrolases (NTPDases) catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP) and inorganic phosphate (Pi). Several NTPDase isoforms have been described in different cells, from pathogenic organisms to animals and plants. Biochemical characterization of nucleotidases/NTPDases has revealed the existence of isoforms with different specificities regarding divalent cations (such as calcium and magnesium) and substrates. In mammals, NTPDases have been implicated in the regulation of thrombosis and inflammation. In parasites, such as Trichomonas vaginalis, Trypanosoma spp., Leishmania spp., Schistosoma spp. and Toxoplasma gondii, NTPDases were found on the surface of the cell, and important processes like growth, infectivity, and virulence seem to depend on their activity. For instance, experimental evidence has indicated that parasite NTPDases can regulate the levels of ATP and Adenosine (Ado) of the host cell, leading to the modulation of the host immune response. In this work, we provide a comprehensive review showing the involvement of the nucleotidases/NTPDases in parasites infectivity and virulence, and how inhibition of NTPDases contributes to parasite clearance and the development of new antiparasitic drugs.

Allergic Inflammation Caused by Dimerized Translationally Controlled Tumor Protein is Attenuated by Cardamonin

We demonstrated in our previous reports that dimeric form of translationally controlled tumor protein (dTCTP) initiates a variety of allergic phenomena. In the present study, we examined whether and how dTCTP's role in allergic inflammation can be modulated or negated. The possible potential of cardamonin as an anti-allergic agent was assessed by ELISA using BEAS-2B cells and OVA-challenged allergic mouse model. The interaction between cardamonin and dTCTP was confirmed by SPR assay. Cardamonin was found to reduce the secretion of IL-8 caused by dTCTP in BEAS-2B cells by interacting with dTCTP. This interaction between dTCTP and cardamonin was confirmed through kinetic analysis (K_D = 4.72 ± 0.07 μM). Also, cardamonin reduced the migration of various inflammatory cells in the bronchoalveolar lavage fluid (BALF), inhibited OVA specific IgE secretion and bronchial remodeling. In addition, cardamonin was observed to have an anti-allergic response by inhibiting the activity of NF-κB. Cardamonin exerts anti-allergic anti-inflammatory effect by inhibiting dTCTP, suggesting that it may be useful in the therapy of allergic diseases.

Synthetic Aurones: New Features for Schistosoma mansoni Therapy

In this work, two synthetic aurones revealed moderate schistosomicidal potential in in vitro and in vivo assays. Aurones (1) and (2) promoted changes in tegument integrity and motor activity, leading to death of adult Schistosoma mansoni worms in in vitro assays. When administered orally (two doses of 50 mg/kg) in experimentally infected animals, synthetic aurones (1) and (2) promoted reductions of 56.20 % and 57.61 % of the parasite load and stimulated the displacement towards the liver of the remaining adult worms. The oogram analysis revealed that the treatment with both aurones interferes with the egg development kinetics in the intestinal tissue. Seeking an action target for compounds (1) and (2), the connection with NTPDases enzymes, recognized as important therapeutic targets for S. mansoni, was evaluated. Molecular docking studies have shown promising results. The dataset reveals the anthelmintic character of these compounds, which can be used in the development of new therapies for schistosomiasis.

Cardamonin Presents in Vivo Activity against Schistosoma mansoni and Inhibits Potato Apyrase

Schistosomiasis, a neglected tropical disease caused by Schistosoma species, harms over 250 million people in several countries. The treatment is achieved with only one drug, praziquantel. Cardamonin, a natural chalcone with in vitro schistosomicidal activity, has not been in vivo evaluated against Schistosoma. In this work, we evaluated the in vivo schistosomicidal activities of cardamonin against Schistosoma mansoni worms and conducted enzymatic apyrase inhibition assay, as well as molecular docking analysis of cardamonin against potato apyrase, S. mansoni NTPDase 1 and S. mansoni NTPDase 2. In a mouse model of schistosomiasis, the oral treatment with cardamonin (400 mg/kg) showed efficacy against S. mansoni, decreasing the total worm load in 46.8 % and reducing in 54.5 % the number of eggs in mice. Cardamonin achieved a significant inhibition of the apyrase activity and the three-dimensional structure of the potato apyrase, obtained by homology modeling, showed that cardamonin may interact mainly through hydrogen bonds. Molecular docking studies corroborate with the action of cardamonin in binding and inhibiting both potato apyrase and S. mansoni NTPDases.

Anti-trypanosomal screening of Salvadoran flora

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and in Central America, it is considered one of the four most infectious diseases. This study aimed to screen the anti-trypanosomal activity of plant species from Salvadoran flora. Plants were selected through literature search for plants ethnobotanically used for antiparasitic and Chagas disease symptomatology, and reported in Museo de Historia Natural de El Salvador (MUHNES) database. T. cruzi was incubated for 72 h with 2 different concentrations of methanolic extracts of 38 species, among which four species, Piper jacquemontianum, Piper lacunosum, Trichilia havanensis, and Peperomia pseudopereskiifolia, showed the activity (≤ 52.0% viability) at 100 µg/mL. Separation of the methanolic extract of aerial parts from Piper jacquemontianum afforded a new flavanone (4) and four known compounds, 2,2-dimethyl-6-carboxymethoxychroman-4-one (1), 2,2-dimethyl-6-carboxychroman-4-one (2), cardamomin (3), and pinocembrin (5), among which cardamomin exhibited the highest anti-trypanosomal activity (IC₅₀ = 66 µM). Detailed analyses of the spectral data revealed that the new compound 4, named as jaqueflavanone A, was a derivative of pinocembrin having a prenylated benzoate moiety at the 8-position of the A ring.

Evaluation of Gibbilimbol B, Isolated from Piper malacophyllum (Piperaceae), as an Antischistosomal Agent

Infections caused by parasitic worms impose a considerable worldwide health burden. One of the most impactful is schistosomiasis, a disease caused by blood-dwelling of the genus Schistosoma that affects more than 230 million people worldwide. Since praziquantel has also been extensively used to treat schistosomiasis and other parasitic flatworm infections, there is an urgent need to identify novel anthelmintic compounds, mainly from natural sources. In this study, the hexane extract from roots of Piper malacophyllum (Piperaceae) showed to be mainly composed for gibbilimbol B by HPLC/ESI-HRMS. Based on this result, this compound was isolated by chromatographic steps and its structure was confirmed by NMR. In vitro bioassays showed that gibbilimbol B was more active than praziquantel against larval stage of S. mansoni, with effective concentrations of 50 % (EC₅₀ ) and 90 % (EC₉₀ ) values of 2.6 and 3.4 μM, respectively. Importantly, gibbilimbol B showed no cytotoxicity to mammalian cells at a concentration 190 times greater than the antiparasitic effect, giving support for the anthelmintic potential of gibbilimbol B as lead compound for novel antischistosomal agents.

Antibacterial, Antibiofilm, and Antischistosomal Activity of Montrichardia linifera (Arruda) Schott (Araceae) Leaf Extracts

With a broad ethnopharmacological tradition in Brazil, Montrichardia linifera has been reported as a potent antirheumatic, antimicrobial, and antiprotozoan agent. However, there is a lack of studies on its effect on bacterial biofilm formation and Schistosoma mansoni worms. This study reports the effects of antibacterial, antibiofilm, and antischistosomal properties of leaf extracts of M. linifera. Phytochemical screening and identification of the main compounds of the extracts were performed. All the extracts evaluated showed antibacterial activity at the concentrations tested. We checked for the presence of flavonoids and derivatives of phenolic acids by the presence of spectra with bands characteristic of these classes in the sample analyzed. The antibacterial assays showed that the best MICs corresponded to 125 µg/mL against Enterococcus faecalis ATCC 29212 in all fractions. The ethanolic and methanolic extracts showed the ability to inhibit biofilm of Staphylococcus aureus ATCC 25123. For the antischistosomal activity, only the acetone and ethyl acetate extracts had a significant effect against helminths, with potent activity at a concentration of 50 µg/mL, killing 100% of the worms after 72 h of incubation. The M. linifera leaf extracts showed antibacterial activity, biofilm inhibition capacity, and anthelmintic activity against S. mansoni.

Three Small Molecule Entities (MPK18, MPK334 and YAK308) with Activity against Haemonchus contortus In Vitro

Due to widespread multi-drug resistance in parasitic nematodes of livestock animals, there is an urgent need to discover new anthelmintics with distinct mechanisms of action. Extending previous work, here we screened a panel of 245 chemically-diverse small molecules for anti-parasitic activity against Haemonchus contortus—an economically important parasitic nematode of livestock. This panel was screened in vitro against exsheathed third-stage larvae (xL3) of H. contortus using an established phenotypic assay, and the potency of select compounds to inhibit larval motility and development assessed in dose-response assays. Of the 245 compounds screened, three—designated MPK18, MPK334 and YAK308—induced non-wildtype larval phenotypes and repeatedly inhibited xL3-motility, with IC₅₀ values of 45.2 µM, 17.1 µM and 52.7 µM, respectively; two also inhibited larval development, with IC₅₀ values of 12.3 µM (MPK334) and 6.5 µM (YAK308), and none of the three was toxic to human liver cells (HepG2). These findings suggest that these compounds deserve further evaluation as nematocidal candidates. Future work should focus on structure–activity relationship (SAR) studies of these chemical scaffolds, and assess the in vitro and in vivo efficacies and safety of optimised compounds against adults of H. contortus.

Piper aduncum essential oil: a promising insecticide, acaricide and antiparasitic. A review

Several studies have assessed the potential of essential oils as substitutes for synthetic pesticides, in order to counter insect resistance to commercial pesticides. Piper aduncum L. is a very common shrub in the Amazon Rainforest and in other subtropical areas. The objective of this review was to analyse the existing information on P. aduncum essential oil as a raw material for new bioproducts for sustainable pest disease management. With this review, we collected and critically analysed 59 papers, representing all the studies that aimed to evaluate the essential oil properties of this species as an insecticide, acaricide and antiparasitic. The chemical composition differs depending on the origin, although phenylpropanoid dillapiole is the most cited component, followed by myristicin, 1,8-cineole and β-ocimene. Between the acaricidal, antiparasitic and synergistic activities, the insecticidal effects are highly promising, with optimal results against the malaria vector Aedes aegypti, with an LC50 that ranges between 57 and 200μg/mL. Acaricidal activity has mainly been reported against Tetranychus urticae, showing an LC50 that ranges between 5.83 and 7.17μg/mL. Antiparasitic activity has predominately been found on Leishmania amazonensis, and antipromastigote activity has been found to be between 23.8 and 25.9μg/mL. Concerning the synergistic effect between dillapiole and synthetic insecticides, four studies on Spodoptera frugiperda found promising results with cypermethrin. In this review, we highlighted the potential of P. aduncum essential oil as a biopesticide, also focusing on the lack of information about applied research. We also provide suggestions for future investigations.

Antischistosomal properties of aurone derivatives against juvenile and adult worms of Schistosoma mansoni

Schistosomiasis is a neglected disease caused by helminth flatworms of the genus Schistosoma, affecting over 240 million people in more than 70 countries. The treatment relies on a single drug, praziquantel, making urgent the discovery of new compounds. Aurones are a natural type of flavonoids that display interesting pharmacological activities, particularly as chemotherapeutic agents against parasites. In pursuit of treatment alternatives, the present work conducted an in vitro and in vivo antischistosomal investigation with aurone derivatives against Schistosoma mansoni. After preparation of aurone derivatives and their in vitro evaluation on adult schistosomes, the three most active aurones were evaluated in cytotoxicity and haemolytic assays, as well as in confocal laser-scanning microscope studies, showing tegumental damage in parasites in a concentration-dependent manner with no haemolytic or cytotoxic potential toward mammalian cells. In a mouse model of schistosomiasis, at a single oral dose of 400 mg/kg, the selected aurones showed worm burden reductions of 35% to 65.0% and egg reductions of 25% to 70.0%. The most active thiophenyl aurone derivative 18, unlike PZQ, had efficacy in mice harboring juvenile S. mansoni, also showing significant inhibition of oviposition by parasites, giving support for the antiparasitic potential of aurones as lead compounds for novel antischistosomal drugs.

Emerging roles of cardamonin, a multitargeted nutraceutical in the prevention and treatment of chronic diseases

Although chronic diseases are often caused by the perturbations in multiple cellular components involved in different biological processes, most of the approved therapeutics target a single gene/protein/pathway which makes them not as efficient as they are anticipated and are also known to cause severe side effects. Therefore, the pursuit of safe, efficacious, and multitargeted agents is imperative for the prevention and treatment of these diseases. Cardamonin is one such agent that has been known to modulate different signaling molecules such as transcription factors (NF-κB and STAT3), cytokines (TNF-α, IL-1β, and IL-6) enzymes (COX-2, MMP-9 and ALDH1), other proteins and genes (Bcl-2, XIAP and cyclin D1), involved in the development and progression of chronic diseases. Multiple lines of evidence emerging from pre-clinical studies advocate the promising potential of this agent against various pathological conditions like cancer, cardiovascular diseases, diabetes, neurological disorders, inflammation, rheumatoid arthritis, etc., despite its poor bioavailability. Therefore, further studies are paramount in establishing its efficacy in clinical settings. Hence, the current review focuses on highlighting the underlying molecular mechanism of action of cardamonin and delineating its potential in the prevention and treatment of different chronic diseases.

Antiparasitic effects of ethanolic extracts of Piper arboreum and Jatropha gossypiifolia leaves on cercariae and adult worms of Schistosoma mansoni

New treatment strategies for schistosomiasis should be evaluated, since resistant strains to the only available drug, Praziquantel, have already been described. Thus, we demonstrated antiparasitic effects of ethanolic extracts of Jatropha gossypiifolia and Piper arboreum on cercariae and adult worms of Schistosoma mansoni. The bioassays were performed at 0–10 000 μg mL−1 concentration for 0–72 h. Adult worms were stained with carmine to assess external and internal damage. The chemical screening was performed using high-performance liquid chromatography. P. arboreum displayed the best cercaricidal effect, with a 100% reduction in viability in just 60 min. The extract of J. gossypiifolia was more effective against adult worms, with 100% viability reduction of male and female worms after 12 and 24 h, respectively. P. arboreum and J. gossypiifolia were equally effective in inhibiting the oviposition of S. mansoni (93% reduction) and causing damage to internal and external structures in adult worms. Flavonoids were identified in both the extracts and phenolic compounds and amides only in P. arboreum. Thus, for the first time, it was proven that ethanolic extracts of P. arboreum and J. gossypiifolia leaves are biologically active against cercariae and adult worms of S. mansoni in vitro.

In vitro and in vivo evaluation of cnicin from blessed thistle (Centaurea benedicta) and its inclusion complexes with cyclodextrins against Schistosoma mansoni

Schistosomiasis, caused by a blood fluke of the genus Schistosoma, afflicts over 230 million people worldwide. Treatment of the disease relies on just one drug, praziquantel. Cnicin (Cn) is the sesquiterpene lactone found in blessed thistle (Centaurea benedicta) that showed antiparasitic activities but has not been evaluated against Schistosoma. However, cnicin has poor water solubility, which may limit its antiparasitic activities. To overcome these restrictions, inclusion complexes with cyclodextrins may be used. In this work, we evaluated the in vitro and in vivo antischistosomal activities of cnicin and its complexes with β-cyclodextrin (βCD) and 2-hydroxypropyl-β-cyclodextrin (HPβCD) against Schistosoma mansoni. Cnicin were isolated from C. benedicta by chromatographic fractionation. Complexes formed by cnicin and βCD (Cn/βCD), as well as by cnicin and HPβCD (Cn/HPβCD), were prepared by coprecipitation and characterized. In vitro schistosomicidal assays were used to evaluate the effects of cnicin and its complexes on adult schistosomes, while the in vivo antischistosomal assays were evaluated by oral and intraperitoneal routes. Results showed that cnicin caused mortality and tegumental alterations in adult schistosomes in vitro, also showing in vivo efficacy after intraperitoneal administration. The oral treatment with cnicin or Cn/βCD showed no significant worm reductions in a mouse model of schistosomiasis. In contrast, Cn/HPβCD complex, when orally or intraperitoneally administered to S. mansoni-infected mice, decreased the total worm load, and markedly reduced the number of eggs, showing high in vivo antischistosomal effectiveness. Permeability studies, using Nile red, indicated that HPβCD complex may reach the tegument of adult schistosomes in vivo. These results demonstrated the antischistosomal potential of cnicin in preparations with HPβCD.

Neurotrophic, anti-neuroinflammatory, and redox balance mechanisms of chalcones

The passage of time that evoke aging; the tilted redox balance that contribute oxidative entropy; the polarization of microglia cells that produce inflammatory phenotype; all represent the intricacies of CNS-dependent disease progression. Neurological diseases that result from CNS injury raise social concerns and the available therapeutic strategies are frustrated by low efficacy, high toxicity, and multiple side effects. However, emergent studies have shown the neuroprotective role of natural compounds - including chalcones - with high efficacy in the protection of CNS structures. These compounds reportedly demonstrate neurotrophic mechanism through the upregulation of neurotrophic factors, anti-apoptotic Bcl-2, and downregulation of Bax protein; anti-neuroinflammatory mechanism via the inhibition of neuroinflammatory pathways, attenuated secretion of pro-inflammatory cytokines, prevention of blood brain barrier (BBB) disruption, and protection against nerve senescence; antioxidant mechanism through the upregulation of Nrf2 activities, inhibition of Keap1, synthesis of antioxidant enzymes, and maintenance of high antioxidant/oxidant ratio. All these mechanisms represent chalcones' neuroprotective mechanisms. In this review, we highlight different pathways involved in CNS-related diseases and elucidate various mechanisms by which chalcones can perturb these shunts as a potential therapeutic modality.

Assessment of the In Vitro Antischistosomal Activities of the Extracts and Compounds from Solidago Microglossa DC (Asteraceae) and Aristolochia Cymbifera Mart. & Zucc. (Aristolochiaceae)

Schistosomiasis, caused by helminth flatworms of the genus Schistosoma, is a neglected tropical disease that afflicts over 230 million people worldwide. Currently, treatment is achieved with only one drug, praziquantel (PZQ). In this regard, the roots of Solidago microglossa (Asteraceae) and Aristolochia cymbifera (Aristolochiaceae) are popularly used as anthelmintic. Despite their medicinal use against helminthiasis, such as schistosomiasis, A. cymbifera, and S. microglossa have not been evaluated against S. mansoni. Then, in this work, the in vitro antischistosomal activity of the crude extracts of A. cymbifera (Ac) and S. microglossa (Sm) and their isolated compounds were investigated against S. mansoni adult worms. Sm (200 μg/mL) and Ac (100–200 μg/mL) were lethal to all male and female worms at the 24 h incubation. In addition, Sm (10–50 μg/mL) and Ac (10 μg/mL) caused significant reduction in the parasite's movements, showing no significant cytotoxicity to Vero cells at the same range of schistosomicidal concentrations. Confocal laser scanning microscopy revealed that Sm and Ac caused tegumental damages and reduced the numbers of tubercles of male schistosomes. Chromatographic fractionation of Sm leads to isolation of bauerenol, α-amirin, and spinasterol, while populifolic acid, cubebin, 2-oxopopulifolic acid methyl ester, and 2-oxopopulifolic acid were isolated from Ac. At concentrations of 25–100 μM, bauerenol, α-amirin, spinasterol, populifolic acid, and cubebin showed significant impact on motor activity of S. mansoni. 2-oxopopulifolic acid methyl ester and 2-oxopopulifolic acid caused 100% mortality and decreased the motor activity of adult schistosomes at 100 μM. This study has reported, for the first time, the in vitro antischistosomal effects of S. microglossa and A. cymbifera extracts, also showing promising compounds against adult schistosomes.

Molecular targets and anticancer activity of quinoline-chalcone hybrids: literature review

α,β-Unsaturated chalcone moieties and quinoline scaffolds play an important role in medicinal chemistry, especially in the identification and development of potential anticancer agents. The multi-target approach or hybridization is considered as a promising strategy in drug design and discovery. Hybridization may improve the affinity and potency while simultaneously decreasing the resistance and/or side effects. The conjugation of quinolines with chalcones has been a promising approach to the identification of potential anticancer agents. Most of these hybrids showed anticancer activities through the inhibition of tubulin polymerization, different kinases, topoisomerases, or by affecting DNA cleavage activity. Accordingly, this class of compounds can be classified based on their molecular modes of action. In this article, the quinolone-chalcone hybrids with potential anticancer activity have been reviewed. This class of compounds might be helpful for the design, discovery and development of new and potential multi-target anticancer agents or drugs.

Single-dose treatment for cutaneous leishmaniasis with an easily synthesized chalcone entrapped in polymeric microparticles

Cutaneous leishmaniasis (CL) is a major health problem in many countries and its current treatment involves multiple parenteral injections with toxic drugs and requires intensive health services. Previously, the efficacy of a single subcutaneous injection with a slow-release formulation consisting of poly(lactide-co-glycolide) (PLGA) microparticles loaded with an antileishmanial 3-nitro-2-hydroxy-4,6-dimethoxychalcone (CH8) was demonstrated in mice model. In the search for more easily synthesized active chalcone derivatives, and improved microparticle loading, CH8 analogues were synthesized and tested for antileishmanial activity in vitro and in vivo. The 3-nitro-2',4',6'-trimethoxychalcone (NAT22) analogue was chosen for its higher selectivity against intracellular amastigotes (selectivity index = 1489, as compared with 317 for CH8) and more efficient synthesis (89% yield, as compared with 18% for CH8). NAT22 was loaded into PLGA / polyvinylpyrrolidone (PVP) polymeric blend microspheres (NAT22-PLGAk) with average diameter of 1.9 μm. Although NAT22-PLGAk showed similar activity to free NAT22 in killing intracellular parasites in vitro (IC50 ~ 0.2 μm), in vivo studies in Leishmania amazonensis - infected mice demonstrated the significant superior efficacy of NAT22-PLGAk to reduce the parasite load. A single intralesional injection with NAT22-PLGAk was more effective than eight injections with free NAT22. Together, these results show that NAT22-PLGAk is a promising alternative for single-dose localized treatment of CL.

Screening of plant derived chalcones on the inhibition of potato apyrase: Potential protein biotechnological applications in health

NTPDases (EC 3.6.1.5) are enzymes belonging to a protein family which have as a common feature the ability to hydrolyze di- and triphosphate nucleotides (ADP and ATP) to monophosphate nucleosides (AMP) in the presence of Ca⁺² and Mg⁺. The potato apyrase has been the first protein of the NTPDase family to be purified. In mammals, these enzymes are involved in physiologic and sick processes as thromboregulation, inflammatory and immunologic responses. In this study, we investigated the in vitro potential of synthetic chalcones on the inhibition of potato apyrase purified from Solanum tuberosum. The protein was purified with high grade purity and its identity was confirmed by electrophoresis, western blot, and LC-MS/MS. Five out of the eight chemically synthetized chalcones analyzed in this study showed significant inhibition of the apyrase activity. The compound with the best rate of inhibition of ATP hydrolytic activity was able to promote 54% inhibition with a concentration of 3.125 μM. Ticlopidine, used as an inhibition drug control, was able to promote inhibitions around 50% of the activity (IC₅₀ = 2.167 μM). Our results with the potato apyrase inhibition with the synthetic chalcones suggest that these compounds may use as potential lead candidates for the treatment of some diseases associated with nucleotides.

H1-antihistamines as antischistosomal drugs: in vitro and in vivo studies

Background

Schistosomiasis is a socioeconomically devastating parasitic infection afflicting hundreds of millions of people and animals worldwide. It is the most important helminth infection, and its treatment relies solely on the drug praziquantel. Oral H1-antihistamines are available worldwide, and these agents are among the most widely used of all medications in children and adults. Given the importance of the drug repositioning strategy, we evaluated the antischistosomal properties of the H1-antihistamine drugs commonly used in clinical practices.

Methods

Twenty-one antihistamine drugs were initially screened against adult schistosomes ex vivo. Subsequently, we investigated the anthelmintic properties of these antihistamines in a murine model of schistosomiasis for both early and chronic S. mansoni infections at oral dosages of 400 mg/kg single dose or 100 mg/kg daily for five consecutive days. We also demonstrated and described the ability of three antihistamines to induce tegumental damage in schistosomes through the use of scanning electron microscopy.

Results

From phenotypic screening, we found that desloratadine, rupatadine, promethazine, and cinnarizine kill adult S. mansoni in vitro at low concentrations (5–15 µM). These results were further supported by scanning electron microscopy analysis. In an animal model, rupatadine and cinnarizine revealed moderate worm burden reductions in mice harboring either early or chronic S. mansoni infection. Egg production, a key mechanism for both transmission and pathogenesis, was also markedly inhibited by rupatadine and cinnarizine, and a significant reduction in hepatomegaly and splenomegaly was recorded. Although less effective, desloratadine also revealed significant activity against the adult and juvenile parasites.

Conclusions

Although the worm burden reductions achieved are all only moderate, comparatively, treatment with any of the three antihistamines is more effective in early infection than praziquantel. On the other hand, the clinical use of H1-antihistamines for the treatment of schistosomiasis is highly unlikely.

Cardamonin: A new player to fight cancer via multiple cancer signaling pathways

Nature's pharmacy has undoubtedly served humans as an affordable and safer health-care regime for a long times. Cardamonin, a chalconoid present in several plants has been known for a longtime to have beneficial properties towards human health. In this review, we aimed to highlight the recent advances achieved in discovering the pharmacological properties of cardamonin. Cardamonin is cardamom-derived chalcone, which plays a role in cancer treatment, immune system modulation, inflammation and pathogens killing. Through the modulation of cellular signaling pathways, cardamonin activates cell death signal to induce apoptosis in malignant cells that results in the inhibition of cancer development. Moreover, cardamonin arrests cell cycle by altering the expression of regulatory proteins during malignant cells division. Due to its relatively selective cytotoxic potential against host malignant cells, cardamonin is emerging as a promising novel experimental anticancer agent. The potential of cardamonin to target various signaling molecules, transcriptional factors, cytokines and enzymes, such as mTOR, NF-κB, Akt, STAT3, Wnt/β-catenin and COX-2 enhances the opportunity to explore it as a new multi-target therapeutic agent. The pharmacokinetic and biosafety profile of cardamonin favor it as a potentially safe biomolecule for pharmaceutical drug development.

Antiparasitic activity of piplartine (piperlongumine) in a mouse model of schistosomiasis

Schistosomiasis is one of the most important parasitic infections in terms of its negative effects on public health and economics. Since praziquantel is currently the only drug available to treat schistosomiasis, there is an urgent need to identify new anthelmintic agents. Piplartine, also known as piperlongumine, is a biologically active alkaloid/amide from peppers that can be detected in high amounts in the roots of Piper tuberculatum. Previously, it has been shown to have in vitro schistosomicidal effects. However, its anthelmintic activity in an animal host has not been reported. In the present work, in vivo antischistosomal properties of isolated piplartine were evaluated in a mouse model of schistosomiasis infected with either adult (patent infection) or juvenile (pre-patent infection) stages of Schistosoma mansoni. A single dose of piplartine (100, 200 or 400 mg/kg) or daily doses for five consecutive days (100 mg/kg/day) administered orally to mice infected with schistosomes resulted in a reduction in worm burden and egg production. Treatment with the highest piplartine dose (400 mg/kg) caused a significant reduction in a total worm burden of 60.4% (P < 0.001) in mice harbouring adult parasites. S. mansoni egg production, a process responsible for pathology in schistosomiasis, was also significantly inhibited by piplartine. Studies using scanning electron microscopy revealed substantial tegumental alterations in parasites recovered from mice. Since piplartine has well-characterized mechanisms of toxicity, is easily available, and is cost-effective, our results indicate that this bioactive molecule derived from medicinal plants could be a potential lead compound for novel antischistosomal agents.

Chemotherapy for human schistosomiasis: how far have we come? What's new? Where do we go from here?

Globally, schistosomiasis threatens more than 700 million lives, mostly children, in poor localities of tropical and sub-tropical areas with morbidity due to acute and chronic pathological manifestations of the disease. After a century since the first antimonial-based drugs were introduced to treat the disease, anti-schistosomiasis drug development is again at a bottleneck with only one drug, praziquantel, available for treatment purposes. This review focuses on promising chemotypes as potential starting points in a drug discovery effort to meet the urgent need for new schistosomicides.

ATP-Diphosphohydrolases in Parasites: Localization, Functions and Recent Developments in Drug Discovery

ATP-diphosphohydrolases (EC 3.6.1.5), also known as ATPDases, NTPases, NTPDases, EATPases or apyrases, are enzymes that hydrolyze a variety of nucleoside tri- and diphosphates to their respective nucleosides, being their activities dependent on the presence of divalent cations, such as calcium and magnesium. Recently, ATP-diphosphohydrolases were identified on the surface of several parasites, such as Trypanosoma sp, Leishmania sp and Schistosoma sp. In parasites, the activity of ATPdiphosphohydrolases has been associated with the purine recuperation and/or as a protective mechanism against the host organism under conditions that involve ATP or ADP, such as immune responses and platelet activation. These proteins have been suggested as possible targets for the development of new antiparasitic drugs. In this review, we will comprehensively address the main aspects of the location and function of ATP-diphosphohydrolase in parasites. Also, we performed a detailed research in scientific database of recent developments in new natural and synthetic inhibitors of the ATPdiphosphohydrolases in parasites.

Promethazine exhibits antiparasitic properties in vitro and reduces worm burden, egg production, hepato-, and splenomegaly in a schistosomiasis animal model

The treatment and control of schistosomiasis, a neglected disease that affects more than 200 million people worldwide, rely on the use of a single drug, praziquantel. A vaccine has yet to be developed and since new drug design and development is a lengthy and costly process, drug repurposing is a promising strategy. In this study, the efficacy of promethazine, a first-generation antihistamine, was evaluated against Schistosoma mansoni ex vivo and in a murine model of schistosomiasis. In vitro assays demonstrated that promethazine affected parasite motility, viability, and it induced severe tegumental damage in schistosomes. The LC₅₀ of the drug was 5.84 μM. Similar to promethazine, schistosomes incubated with atropine, a classical anticholinergic drug, displayed reduced motor activity. In an animal model, promethazine treatment was introduced at an oral dose of 100 mg/kg for five successive days at different intervals from the time of infection, for the evaluation of the stage-specific susceptibility (pre-patent and patent infections). Various parasitological criteria indicated the in vivo antischistosomal effects of promethazine: there were significant reductions in worm burden, egg production, and hepato- and splenomegaly. The highest worm burden reduction was achieved with promethazine in patent infections (> 90%). Taken together, considering the importance of the repositioning of drugs in infectious diseases, especially those related to poverty, our data revealed the possibility of promethazine repositioning as an antischistosomal agent.

Vanillin-Related N-Acylhydrazones: Synthesis, Antischistosomal Properties and Target Fishing Studies

Background:

Schistosomiasis is a neglected disease, which affects millions of people in developing countries. Its treatment relies on a single therapeutic alternative, the praziquantel. This situation may lead to drug resistance which, in turn, made urgent the need for new antischistosomal agents. Nacylhydrazones are usually explored as good antimicrobial agents, but the vanillin-related N-acylhydrazones have never been tested by their antiparasitic potential.

Objective:

Herein, we report the synthesis of seven analogues, three of them unpublished, their biological investigation against Schistosoma mansoni and Target Fishing studies.

Methods:

The compounds were synthesized following classical synthetical approaches. The anthelmintic potential was assessed as well as their cytotoxicity profile. Confocal laser scanning microscopy and target fishing study were performed to better understand the observed antischistosomal activity.

Results:

Compound GPQF-407 exhibited good antischistosomal activity (47.91 µM) with suitable selectivity index (4.14). Confocal laser scanning microscopy revealed that it triggered severe tegumental destruction and tubercle disintegration. Target fishing studies pointed out some probable targets, such as the serine-threonine kinases, dihydroorotate dehydrogenases and carbonic anhydrase II.

Conclusion:

The GPQF-407 was revealed to be a promising antischistosomal agent which, besides presenting the N-acylhydrazone privileged scaffold, also could be easily synthesized on large scales from commercially available materials.

Phenotypic screening of nonsteroidal anti-inflammatory drugs identified mefenamic acid as a drug for the treatment of schistosomiasis

Background

Treatment and control of schistosomiasis, one of the most insidious and serious parasitic diseases, depend almost entirely on a single drug, praziquantel. Since the funding for drug development for poverty-associated diseases is very limited, drug repurposing is a promising strategy. In this study, 73 nonsteroidal anti-inflammatory drugs (NSAIDs) commonly used in medical and veterinary fields were evaluated for their anti-schistosomal properties.

Methods

The efficacy of NSAIDs was first tested against adult Schistosoma mansoni ex vivo using phenotypic screening strategy, effective drugs were further tested in a murine model of schistosomiasis. The disease parameters measured were worm and egg burden, hepato- and splenomegaly.

Findings

From 73 NSAIDs, five (mefenamic acid, tolfenamic acid, meclofenamic acid, celecoxib, and diclofenac) were identified to effectively kill schistosomes. These results were further supported by scanning electron microscopy analysis. In addition, the octanol-water partition coefficient, both for neutral and ionized species, revealed to be a critical property for the ex vivo activity profile. Compounds were then tested in vivo using both patent and a prepatent S. mansoni infection in a mouse model. The most effective NSAID was mefenamic acid, which highly reduced worm burden, egg production, and hepato- and splenomegaly.

Interpretation

The treatment regimen used in this study is within the range for which mefenamic acid has been used in clinical practice, thus, it is demonstrated the capacity of mefenamic acid to act as a potent anti-schistosomal agent suitable for clinical repurposing in the treatment of schistosomiasis.

Biological Evaluation and Docking Analysis of Potent BACE1 Inhibitors from Boesenbergia rotunda

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder characterized by progressive impairment of cognitive functions. Beta-site amyloid precursor protein cleaving enzyme1 (BACE1) is essential for the formation of β-amyloid peptide (Aβ), a major constituent of amyloid plaques that represent a neuropathological hallmark of this disorder. To find alternative therapies for AD sourced from natural products, the present study focused on three flavonoids from Boesenbergia rotunda, namely, cardamonin, pinocembrin, and pinostrobin. Biological evaluation showed that cardamonin presented the strongest BACE1 inhibition, with an The half maximal inhibitory concentration (IC₅₀) value of 4.35 ± 0.38 µM, followed by pinocembrin and pinostrobin with 27.01 ± 2.12 and 28.44 ± 1.96 µM, respectively. Kinetic studies indicated that the inhibitory constants (K_i) for cardamonin, pinocembrin, and pinostrobin against BACE1 were 5.1, 29.3, and 30.9 µM, respectively. Molecular docking studies showed that the tested compounds did not bind to the BACE1 active site, consistent with the biological results, illustrating non-competitive inhibitory activity for all three compounds. In addition, the lowest binding energy of the most proposed complexes of cardamonin, pinocembrin, and pinostrobin with BACE1 were -9.5, -7.9, and -7.6 kcal/mol, respectively. Overall, we provide the first evidence that these flavonoids from B. rotunda may be considered as promising AD preventative agents through inhibition of Aβ formation.

In Vitro and In Vivo Studies of Spironolactone as an Antischistosomal Drug Capable of Clinical Repurposing

Schistosomiasis is a parasitic flatworm disease that infects over 200 million people worldwide, especially in poor communities. Treatment and control of the disease rely on just one drug, praziquantel. Since funding for drug development for poverty-associated diseases is very limited, drug repurposing is a promising strategy. In this study, from a screening of 13 marketed diuretics, we identified that spironolactone, a potassium-sparing diuretic, had potent antischistosomal effects on Schistosoma mansoni in vitro and in vivo in a murine model of schistosomiasis. In vitro, spironolactone at low concentrations (<10 µM) is able to alter worm motor activity and the morphology of adult schistosomes, leading to parasitic death. In vivo, oral treatment with spironolactone at a single dose (400 mg/kg) or daily for five consecutive days (100 mg/kg/day) in mice harboring either patent or prepatent infections significantly reduced worm burden, egg production, and hepato- and splenomegaly (P < 0.05 to P < 0.001). Taken together, with the safety profile of spironolactone, supported by its potential to affect schistosomes, these results indicate that spironolactone could be a potential treatment for schistosomiasis and make it promising for repurposing.

In Vitro and in Vivo Antischistosomal Activities of Chalcones

In this study, we evaluated the in vitro and in vivo schistosomicidal activities of chalcones against Schistosoma mansoni worms. In vitro assays revealed that chalcones 1 and 3 were the most active compounds, without affecting significantly mammalian cells. Confocal laser scanning microscopy and scanning electron microscopy studies revealed reduction on the numbers of tubercles and morphological alterations in the tegument of S. mansoni worms after in vitro incubation with chalcones 1 and 3. In a mouse model of schistosomiasis, the oral treatment (400 mg/kg) with chalcone 1 or 3 significantly caused a total worm burden reduction in mice. Chalcone 1 showed significant inhibition of the S. mansoni ATP diphosphohydrolase activity, which was corroborated by molecular docking studies. The results suggested that chalcones could be explored as lead compounds with antischistosomal properties.

Glycolysis inhibition via mTOR suppression is a key step in cardamonin-induced autophagy in SKOV3 cells

Background

Autophagy occurs in cells that undergoing nutrient deprivation. Glycolysis rapidly supplies energy for the proliferation of cancer cells. Cardamonin inhibits proliferation and enhances autophagy by mTORC1 suppression in ovarian cancer cells. Here, we investigate the relationship between cardamonin-triggered autophagy and glycolysis inhibition via mTORC1 suppression.

Methods

Treated with indicated compounds, ATP content and the activity of hexokinase (HK) and lactate dehydrogenase (LDH) were analyzed by the assay kits. Autophagy was detected by monodansylcadaverin (MDC) staining. The relationship between cardamonin-triggered autophagy and glycolysis inhibition via mTORC1 suppression was analyzed by Western blot.

Results

We found that cardamonin inhibited the lactate secretion, ATP production, and the activity of HK and LDH. The results demonstrated that cardamonin enhanced autophagy in SKOV3 cells, as indicated by acidic compartments accumulation, microtubule-associated protein 1 Light Chain 3-II (LC3-II) and lysosome associated membrane protein 1 up-regulation. Our results showed that the activation of mTORC1 signaling and the expression HK2 were reduced by cardamonin; whereas the phosphorylation of AMPK (AMP-activated protein kinase) was increased. We also confirmed that the AMPK inhibitor, Compound C, reversed cardamonin-induced upregulation of LC3-II.

Conclusion

These results suggest that cardamonin-induced autophagy is associated with inhibition on glycolysis by down-regulating the activity of mTORC1 in ovarian cancer cells.

Structure⁻Activity Relationship of Piplartine and Synthetic Analogues against Schistosoma mansoni and Cytotoxicity to Mammalian Cells

Schistosomiasis, caused by helminth flatworms of the genus Schistosoma, is an infectious disease mainly associated with poverty that affects millions of people worldwide. Since treatment for this disease relies only on the use of praziquantel, there is an urgent need to identify new antischistosomal drugs. Piplartine is an amide alkaloid found in several Piper species (Piperaceae) that exhibits antischistosomal properties. The aim of this study was to evaluate the structure–function relationship between piplartine and its five synthetic analogues (19A, 1G, 1M, 14B and 6B) against Schistosoma mansoni adult worms, as well as its cytotoxicity to mammalian cells using murine fibroblast (NIH-3T3) and BALB/cN macrophage (J774A.1) cell lines. In addition, density functional theory calculations and in silico analysis were used to predict physicochemical and toxicity parameters. Bioassays revealed that piplartine is active against S. mansoni at low concentrations (5⁻10 µM), but its analogues did not. In contrast, based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, piplartine exhibited toxicity in mammalian cells at 785 µM, while its analogues 19A and 6B did not reduce cell viability at the same concentrations. This study demonstrated that piplartine analogues showed less activity against S. mansoni but presented lower toxicity than piplartine.

In vitro schistosomicidal and antiviral activities of Arctium lappa L. (Asteraceae) against Schistosoma mansoni and Herpes simplex virus-1

Schistosomiasis and herpes diseases represent serious issues to the healthcare systems, infecting a large number of people worldwide, mainly in developing countries. Arctium lappa L. (Asteraceae), known as "bardana" and "burdock", is a medicinal plant popularly used for several purposes, including as antiseptic. In this study, we evaluated the in vitro schistosomicidal and antiherpes activities of the crude extract of A. lappa, which have not yet been described. Fruits of A. lappa L. were extracted by maceration with ethanol: H₂O (96:4 v/v) in order to obtain the hydroalcoholic extract of A. lappa (AL). In vitro schistosomicidal assays were assessed against adult worms of Schistosoma mansoni, while the in vitro antiviral activity of AL was evaluated on replication of Herpes simplex virus type-1 (HSV-1). Cell viability was measured by MTT assay, using Vero cells and chemical composition of AL was determined by qualitative UPLC-ESI-QTOF-MS analysis. UPLC-ESI-QTOF-MS analysis of AL revealed the presence of dibenzylbutyrolactone lignans, such as arctiin and arctigenin. Results showed that AL was not cytotoxic to Vero cells even when tested at 400μg/mL. qPCR results indicated a significant viral load decreased for all tested concentrations of AL (400, 50, and 3.125μg/mL), which showed similar antiviral effect to acyclovir (50μg/mL) when tested at 400μg/mL. Also, AL (400, 200, and 100μg/mL) caused 100% mortality and significantly reduction on motor activity of all adult worms of S. mansoni. Confocal laser scanning microscopy showed tegumental morphological alterations and changes on the numbers of tubercles of S. mansoni worms in a dose-dependent manner after treatment with AL. This report provides the first evidence for the in vitro schistosomicidal and antiherpes activities of AL, opening the route to further schistosomicidal and antiviral studies with AL and their compounds, especially lignans.

Cyclohexene-fused 1,3-oxazines with selective antibacterial and antiparasitic action and low cytotoxic effects

Oxazine derivatives, a class of heterocyclic compounds, exhibit a variety of biological properties, such as anticonvulsant and antitumor activities. In this study, we evaluated the effect of two cyclohexene-fused 1,3-oxazines (cis‑1-benzyl-N-phenyl-1,4,4a,5,8,8a-hexahydro-3,1-benzoxazin-2-imine (1) and trans‑N-phenyl-1,4,4a,5,8,8a-hexahydro-3,1-benzoxazin-2-imine (2)) in cultures of Bacillus cereus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Serratia marcescens, Shigella flexneri and Staphylococcus aureus by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Additionally, the ex vivo antiparasitic activity of oxazines was assessed against Schistosoma mansoni, a helminth that is one of the major agents of the disease schistosomiasis Also, oxazines were evaluated on three tumor cell lines, NCI-H292 (human lung carcinoma), MCF-7 (human breast adenocarcinoma) and HEp-2 (human cervix carcinoma), and two normal cell lines (Vero and red blood cells). Bioassays revealed that oxazine 2 is more effective against bacteria than oxazine 1, with the lowest MIC and MBC values of 3.91 and 32.5μg/mL, respectively. Similarly, compound 2 demonstrated higher antiparasitic activity than 1, and scanning electron microscopy analysis showed several morphological alterations in the tegument of worms in a concentration-dependent manner. In contrast, both oxazines exhibited low cytotoxic effects on cancer and normal cell lines. These results indicated that oxazines exerted direct effects on bacteria and parasite schistosomes. More importantly, since schistosomiasis control programs rely on one drug, praziquantel, oxazines may have the potential to become new antischistosomal agents.