Search Results (204)

Malaria is one of the diseases that is a serious threat to global health, with millions of cases reported worldwide in recent years. The treatment of malaria is still a challenge due to its complex pathogenesis, resistance to many of the antimalarial drugs, and adverse toxicity. Nowadays, the possibilities of applying new natural molecules alone or in combination is being researched. However, many of these substances possess low aqueous solubility, which limits their bioavailability. The solubility of such substances could be improved by applying various techniques for their nanoencapsulation, e.g., incorporation in nanocapsules, liposomes, lipid nanoparticles, etc. The current review emphasizes studies on the nanoencapsulation of some of the well-known natural antimalarial agents (quinine, artemisinin) as well as substances with newly demonstrated antimalarial potential (piperine, quercetin, etc.). The review also discusses the opportunity to simultaneously load two natural agents in nanoparticles. Special focus is given to the metal nanoparticles (e.g., silver, gold, etc.) obtained by green synthesis from plants. Full article

Quinazolin-4(3H)-ones are nitrogen heterocycles that have attracted considerable interest over many years due to their important biological and pharmacological properties. It has been shown that quinazolinone derivatives exhibit, e.g., analgesic, anti-inflammatory, antibacterial, anticonvulsant, antifungal, and antitumor activities. Some of these compounds have found applications in medicine; for instance, Zydelig (Idelalisib) has been approved for the treatment of several types of blood cancers. Furthermore, the quinazolinone skeleton is an important structural moiety present in many naturally occurring alkaloids, such as Febrifugine, a potent anti-malarial agent. To date, numerous synthetic methods have been developed for the synthesis of quinazolinone derivatives. Among them, multicomponent reactions (MCRs) have emerged as a powerful tool, allowing for the rapid and straightforward construction of the quinazolinone scaffold from readily available substrates. This review article presents a concise overview of selected strategies for synthesizing quinazolinone frameworks via one-pot MCRs. The reported methods are categorized into three main groups: metal-catalyzed reactions; isatoic-anhydride-based strategies, utilizing isatoic anhydride as a key starting material, and alternative approaches involving, among others, the utilization of N-(2-aminobenzoyl)benzotriazoles or aryldiazonium salts as efficient building materials. Full article

Background: Echinops is a genus of spiny, herbaceous perennials in the Asteraceae family, known for its distinct morphology and broad pharmacological potential. Both traditional and modern medicinal systems have identified species in this genus as sources of bioactive compounds with anti-inflammatory, antimalarial, antidiabetic, anticancer, and neuroprotective effects. Aims: This study aimed to conduct a systematic literature review and update previous overviews of the recently reported phytochemicals and pharmacological properties of Echinops, systematically summarizing biological activities and their therapeutic applications. Methods: Major electronic medical databases—PubMed, Scopus, Science Direct, Web of Science, and Google Scholar—were systematically searched for publications from 1990 to 2025. Results: A total of 134 studies met our inclusion criteria. Thiophenes and terpenes emerged as characteristic metabolites of the genus, and along with flavonoids and alkaloids, contributed to a wide range of bioactivities. Experimental evidence supports the potential of these compounds as multifunctional agents, although clinical validation remains limited. Conclusions: Echinops is a promising source of structurally diverse metabolites with therapeutic relevance. Further pharmacological and toxicological studies are needed to establish their efficacy and ensure safe medical application. Full article

Introduction: Malaria is a tropical disease caused by the parasite Plasmodium sp., which is considered a significant public health challenge, particularly in Africa. Among the species related to human infection, P. falciparum and P. vivax are known for their high incidence and pathogenicity. Despite several approved drugs in the treatment, the increase in resistance mechanisms is becoming increasingly prevalent, which makes the discovery of effective and safer drugs challenging. Thus, it is necessary to explore new mechanisms of action for the discovery of innovative antimalarial agents. Among the explored targets, proteases, especially subtilisin, have shown great promise in the development of new therapeutic options. Method: A narrative review was conducted using the main databases to provide critical information about the subtilisin to design antimalarial drugs. Results: Critical data were found about the isoforms of subtilisins, highlighting SUB1 and SUB2. SBDD approaches were able to show that compounds designed to target the catalytic Asp³⁷², His⁴²⁸, and Ser⁶⁰⁶, and other such Leu⁴⁶⁹, Gly⁴⁶⁷, and Asn⁵²⁰ against SUB1, presented critical results. In addition, quinoline, benzopyran, and triterpene derivatives and peptide inhibitors show their importance, and these scaffolds can be explored in further work. Conclusions: Considering the relevance of this target, this review provided insights into medicinal chemistry, the discovery of antimalarial drugs that act by inhibiting subtilisin, and promoted a promising initiative to combat malaria. Full article

The use of metal-based complexes is currently taking centre stage in the field of nanomedicine for the treatment and control of various ailments. Rhenium(I) tricarbonyl complexes have frequently been evaluated in vitro for their anticancer activities, and a few have advanced to in vivo and clinical trials, owing to the distinct application characteristics of these complexes. Their inception in drug development is key. This study explores a detailed chronological overview of the medical applications of Re(I) tricarbonyl complexes over the past six years (2019–2024), focusing on their applications and clinical tests in the control and management of various ailments. An in-depth examination of their activities in anticancer treatments, Chagas disease, antifungal infections, antimalarial, and microbial infections was conducted, comparing the complexes to various standard antibiotics, conventional antimalarial drugs, antifungals, and standard anticancer agents. Full article

Malaria continues to pose a significant global health burden, driving the search for novel antimalarial agents to address emerging drug resistance. This study evaluated the antiplasmodial potential of Ziziphus mauritiana Lam. (Rhamnaceae) roots through an integrated phytochemical and pharmacological approach. The ethanol extract, along with its derived fractions, demonstrated potent in vitro activity against the chloroquine-sensitive Plasmodium falciparum strain 3D7 (Pf3D7), with the ethyl acetate-soluble (IC₅₀ = 11.35 µg/mL) and alkaloid-rich (IC₅₀ = 4.75 µg/mL) fractions showing particularly strong inhibition. UHPLC-DAD-ESI-QTOF-MS/MS-based molecular networking enabled the identification of thirty-two secondary metabolites (1–32), comprising twenty-five cyclopeptide alkaloids (CPAs), five of which had not yet been described (11, 20, 22, 23, 25), and seven known triterpenoids. Bioactivity-guided isolation yielded thirteen purified compounds (5, 6, 14, 26–30, 32–36), with betulinic acid (30; IC₅₀ = 19.0 µM) and zizyberenalic acid (32; IC₅₀ = 20.45 µM) exhibiting the most potent antiplasmodial effects. Computational ADMET analysis identified mauritine F (4), hemisine A (10), and nummularine R (21) as particularly promising lead compounds, demonstrating favourable pharmacokinetic properties, low toxicity profiles, and predicted activity against both family A G protein-coupled receptors and evolutionarily distinct Plasmodium protein kinases. Quantitative analysis revealed exceptionally high concentrations of key bioactive constituents, notably zizyberenalic acid (24.3 mg/g) in the root extracts. These findings provide robust scientific validation for the traditional use of Z. mauritiana in malaria treatment while identifying specific cyclopeptide alkaloids and triterpenoids as valuable scaffolds for antimalarial drug development. The study highlights the effectiveness of combining advanced metabolomics, bioassay-guided fractionation, and computational pharmacology in natural product-based drug discovery against resistant malaria strains. Full article

Plasmodium falciparum is the causative agent of malaria, a parasitic disease that affects millions of people in terms of prevalence and is associated with hundreds of thousands of deaths. Current antimalarial medications, in addition to exhibiting moderate to serious adverse reactions, are not efficacious enough due to factors such as drug resistance. In silico approaches can speed up the discovery and design of new molecules with wide-spectrum antimalarial activity. Here, we report a unified computational methodology combining a perturbation theory machine learning model based on multilayer perceptron networks (PTML-MLP) and the fragment-based topological design (FBTD) approach for the prediction and design of novel molecules virtually exhibiting versatile antiplasmodial activity against diverse P. falciparum strains. Our PTML-MLP achieved an accuracy higher than 85%. We applied the FBTD approach to physicochemically and structurally interpret the PTML-MLP, subsequently extracting several suitable molecular fragments and designing new drug-like molecules. These designed molecules were predicted as multi-strain antiplasmodial inhibitors, thus representing promising chemical entities for future synthesis and biological experimentation. The present work confirms the potential of combining PTML modeling and FBTD for early antimalarial drug discovery while opening new horizons for extended computational applications for antimicrobial research and beyond. Full article

Malaria is a parasitic infectious disease that is endemic in many tropical countries. Even though several effective antimalarial agents have been implemented, treatment failure still occurs, and malaria continues to cause neurological complications and death, particularly in severe or drug-resistant cases. Hence, novel therapeutic agents with distinct mechanisms of action, as well as alternative chemical compounds that can overcome resistance, are still needed to improve malaria therapy. This study aimed to investigate the antimalarial activities of Brucea javanica, a tropical plant extracts against Plasmodium falciparum, the major species associated with severe malaria. In this study, malaria parasites were treated with plant extracts using single and co-incubation methods, along with artesunate and chloroquine, and their inhibitory effect on parasite development was determined by microscopy. The results show that all tested doses of the extracts that effectively inhibited malaria parasites did not cause hemolysis of red blood cells (RBCs). The root extract (RE) and fruit extract (FE) inhibited parasite growth at IC₅₀ values of 0.41 ± 1.14 µg/mL and 0.26 ± 1.15 µg/mL, respectively. These plant extracts significantly interrupted malaria development at the ring stage, as presented by a reduction in the conversion rate to trophozoites and schizonts. The defective parasites treated with plant extracts were characterized by nuclear clumping, leading to pyknotic cell death. Moreover, RE and FW extracts elicited an additive effect with artesunate and chloroquine, significantly reducing IC₉₀ levels for the inhibition of parasite development. In conclusion, B. javanica extracts inhibited the asexual blood-stage development of malaria parasites. They distinctively show the additive effects of ATS and CRQ, elucidating their potential for further studies on novel formulas of antimalarial drug regimens. Full article

The crystal structure of the hydrated form of 7-chloro-4-(4-methyl-1-piperazinyl)quinoline (BPIP) was determined by single-crystal X-ray diffraction analysis. This study revealed a one-dimensional supramolecular network stabilized by hydrogen bonding interactions between BPIP and water molecules. This compound represents one-half of a piperaquine molecule, a member of the 4-aminoquinoline class of antimalarial treatments, currently employed as a partner agent in modern combination therapies. As a simplified structural analog, BPIP can serve as a critical model system for probing the intermolecular interactions, physicochemical properties, and structural behavior of the parent compound. As a result, conducting a thorough solid-state characterization of BPIP is critical for gaining insight into its physical properties and verifying the material’s identity and purity. Full article

Triazolopyrimidine and its analogs represent an important scaffold in medicinal chemistry research. The heterocycle of 1,2,4-triazolo[1,5-a] pyrimidine (1,2,4-TAP) serves as a bioisostere candidate for purine scaffolds, N-acetylated lysine, and carboxylic acid. This study modeled the quantitative structure–activity relationship (QSAR) of 125 congeners of 1,2,4-TAP from the ChEMBL database in the inhibition of Plasmodium falciparum using six machine learning algorithms. The most significant features among 306 molecular descriptors, including one molecular outlier, were selected using recursive feature elimination. A ratio of 20% was used to split the x- and y-matrices into 99 training and 24 test compounds. The regression models were built using machine learning sci-kit-learn algorithms (multiple linear regression (MLR), k-nearest neighbours (kNN), support vector regressor (SVR), random forest regressor (RFR) RIDGE regression, and LASSO). Model performance was evaluated using the coefficient of determination (R²), mean squared error (MSE), mean absolute error (MAE), root mean squared error (RMSE), p-values, F-statistic, and variance inflation factor (VIF). Five significant variables were considered in constructing the model (p < 0.05) with the following regression equation: pIC₅₀ = 5.90 − 0.71npr1 − 1.52pmi3 + 0.88slogP − 0.57vsurf-CW2 + 1.11vsurf-W2. On five-fold cross-validation, three algorithms—kNN (MSE = 0.46, R² = 0.54, MAE = 0.54, RMSE = 0.68), SVR (MSE = 0.33, R² = 0.67, MAE = 0.46, RMSE = 0.57), and RFR (MSE = 0.43, R² = 0.58, MAE = 0.51, RMSE = 0.66)—showed strong robustness, efficiency, and reliability in predicting the pIC₅₀ of 1,2,4-triazolo[1,5-a]pyrimidine. The models provided useful data on the functionalities necessary for developing more potent 1,2,4-TAP analogs as anti-malarial agents. Full article

Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in older adults. Its pathogenesis involves multiple factors, including aging, environmental influences, genetic predisposition, oxidative stress, metabolic dysfunction, and immune dysregulation. Currently, AMD treatment focuses primarily on wet AMD, managed through repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF) therapies. While anti-VEGF agents represent a major breakthrough in wet AMD care, repeated injections may lead to incomplete responses or resistance in some patients, and carry a risk of progressive fibrosis. Artemisinin (ART) and its derivatives, originally developed as antimalarial drugs, exhibit a broad spectrum of pleiotropic activities beyond their established use, including anti-inflammatory, anti-angiogenic, antioxidant, anti-fibrotic, mitochondrial regulatory, lipid metabolic, and immunosuppressive effects. These properties position ART as a promising therapeutic candidate for AMD. A growing interest in ART-based therapies for AMD has emerged in recent years, with numerous studies demonstrating their potential benefits. However, no comprehensive review has systematically summarized the specific roles of ART and its derivatives in AMD pathogenesis and treatment. This paper aims to fill the knowledge gap by synthesizing the therapeutic efficacy and molecular mechanisms of ART and its derivatives in AMD, thereby providing a foundation for future investigations. Full article

Quinolones represent one of the largest classes of synthetic antibiotics used in both human and veterinary medicine. Since the discovery of nalidixic acid, a substantial body of research has been carried out on quinolones, resulting in the synthesis of several quinolone derivatives with exceptional pharmacology. In addition to their antibacterial action, quinolones have a broad spectrum of diverse biological activities. In this regard, the present review examines the literature of recent years describing synthesis protocols, reactivity and biological properties, with particular emphasis on the antibacterial, antimalarial, antitrypanosomal, antileishmanial, antiviral and anticancer activities of this famous class of molecules. Finally, this review highlights the potential of quinolones as preferred pharmacophores in medicinal chemistry. The aim is to highlight the innovative aspects of the rational design of new therapeutic agents with this structural motif, in the face of emerging antibiotic resistance and the urgent need for new active molecules. Full article

Capirona macrophylla is a Rubiaceae known as “mulateiro”. Ethnobotanical extracts have been used for skin treatment and in the management of leishmaniasis and malaria. Objectives: The metabolites in aqueous extracts from wood bark, leaves, and stems were identified, and their in silico docking and in vitro cellular efficacy against Leishmania amazonensis and Plasmodium falciparum were evaluated. Methods: The extracts were analyzed by UHPLC/HRMSⁿ using untargeted metabolomics approach with MSDial, MSFinder, and GNPS software for metabolite identification and spectra clustering. The most abundant metabolites underwent molecular docking using AutoDock via PyRx, targeting the dihydroorotate dehydrogenase from Leishmania and P. falciparum, and evaluated through molecular dynamics simulations using Gromacs. In vitro biological assays were conducted on 60 HPLC-fractions against these parasites. Results: Metabolomics analysis identified 5100 metabolites in ESI+ and 2839 in ESI− spectra among the “mulateiro” samples. GNPS clustering highlighted large clusters of quercetin and chlorogenic acid groups. The most abundant metabolites were isofraxidin, scopoletin, 5(S)-5-carboxystrictosidine, loliolide, quercetin, quinic acid, caffeoylquinic acid (and isomers), chlorogenic acid, neochlorogenic acid, tryptophan, N-acetyltryptophan, epicatechin, procyanidin, and kaempferol-3-O-robinoside-7-O-rhamnoside. Molecular docking pointed to 3,4-dicaffeoylquinic acid and kaempferol as promising inhibitors. The in vitro assays yielded four active HPLC-fractions against L. amazonensis with IC50 values ranging from 175.2 μg/mL to 194.8 μg/mL, and fraction G29 showed an IC50 of 119.8 μg/mL against P. falciparum. Conclusions: The ethnobotanical use of “mulateiro” wood bark tea as an antimalarial and antileishmanial agent was confirmed through in vitro assays. We speculate that these activities are attributed to linoleic acids and quinic acids. Full article

Natural compounds containing nitrogen are a source of many biologically active molecules used as drugs. Due to their multidirectional effects, they represent effective therapeutic compounds in many medical areas. Flavonoids, as well as their bioprecursors, chalcones, that occur in plants possess a number of medicinal benefits. Their synthetic amino derivatives constitute a large group of compounds that exhibit pharmacological activity. Due to the increasing level of drug resistance among patients, new therapeutic agents and options are urgently needed. Therefore, aminoflavonoids may be a promising source of new drugs. In this review, the biological activities of flavonoids, including chalcones, with complexes containing a nitrogen atom and the aminoflavones Ru and Pt are summarized. The purpose of this review is to provide an overview of the synthesis and pharmacological activity of aminoflavonoids and to show how synthetic modifications of these compounds can influence their biological activities. It covers the most recent reports on obtaining aminoflavones, aminochalcones, and their derivatives, along with information about their anticancer, antimicrobial, antimalarial, antiviral, and anti-inflammatory activities. Full article

Artesunate (ART), an artemisinin-derived semi-synthetic sesquiterpene lactone distinguished by its unique endoperoxide group, has become a cornerstone of clinical antimalarial therapy. Recent research has demonstrated its broad pharmacological profile, including its potent antimalarial, anti-inflammatory, anti-tumor, antidiabetic, immunomodulatory, and anti-fibrotic properties. These discoveries have significantly broadened the therapeutic scope of ART and offer new perspectives for its potential use in treating gastrointestinal disorders. Mechanistically, ART exerts significant therapeutic effects against diverse gastrointestinal pathologies—such as gastric ulcers, ulcerative colitis (UC), hepatic fibrosis (HF), gastric cancer, hepatocellular carcinoma, and colorectal cancer—via multimodal mechanisms, including cell cycle modulation, apoptosis induction, the suppression of tumor cell invasion and migration, proliferation inhibition, ferroptosis activation, and immune regulation. This review evaluates existing evidence on ART’s therapeutic applications and molecular mechanisms in digestive diseases, intending to elucidate its clinical translation potential. ART emerges as a promising multi-target agent with significant prospects for improving the management of gastrointestinal disorders. Full article