Interaction of apigenin-7-O-glucoside with pyrimethamine against Toxoplasma gondii growth

Comprehensive Insights into the Development of Antitoxoplasmosis Drugs: Current Advances, Obstacles, and Future Perspectives

Current therapies for toxoplasmosis rely on a few drugs, most of which have severe side effects, and seeking ideal therapies for different types of toxoplasmosis is a long-term and challenging mission. Research and development (R&D) of novel drugs against Toxoplasma gondii (T. gondii) has focused on two main directions, the structural modification of lead compounds and natural products. Here we summarize the recent advances in the development of anti-T. gondii drugs from these two perspectives and provide comprehensive insights, reflecting on the advantages and selected molecules in each field. This review also focuses on the current obstacles to the development of novel anti-T. gondii agents, proposes comprehensive solutions, and facilitates future development.

Phytochemical profiling and in silico evaluation of Artemisia absinthium compounds targeting Leishmania N-myristoyltransferase: molecular docking, drug-likeness, and toxicity analyses

Background

Artemisia absinthium has long been recognized for its therapeutic properties against various diseases. Among these is leishmaniasis, a parasitic infection that remains a global health challenge. Targeting Leishmania N-myristoyltransferase (NMT), a crucial enzyme for parasite survival, represents a promising therapeutic approach. The bioactive compounds in A. absinthium could potentially inhibit NMT and serve as new treatment options for leishmaniasis.

Aim

This study aims to investigate the phytochemical composition, drug-likeness, and molecular dynamics of A. absinthium bioactive compounds targeting Leishmania NMT, identifying potent inhibitors that could serve as new drug candidates.

Method

The extract of A. absinthium was analyzed using High-Performance Liquid Chromatography (HPLC), identifying nine phenolic compounds, with kaempferol (10.72%) and chlorogenic acid (4.43%) being the most abundant. Drug-likeness and toxicity were evaluated using SwissADME and OSIRIS Property Explorer, focusing on adherence to Lipinski's rule of five and Ghose's filter. Molecular docking studies were conducted to evaluate the binding affinity of these compounds to NMT. Molecular dynamics (MD) simulations were performed to assess the stability and flexibility of the NMT-apigenin complex.

Results

Molecular docking identified apigenin as the most potent NMT inhibitor, with a binding energy of -9.6 kcal/mol, forming significant hydrogen bonds with threonine residues 203 and 189. Drug-likeness analysis revealed that most compounds adhered to Lipinski's rule of five, indicating favorable pharmacokinetic properties. MD simulations confirmed the stability of the NMT-apigenin complex, with root mean square deviation (RMSD) values of 0.04 nm, root mean square fluctuation (RMSF) values between 0.05 and 0.35 nm, and radius of gyration (Rg) values ranging from 2.24 to 2.30 nm. Normal mode analysis further supported the complex's stability and flexibility.

Conclusion

The findings of this study underscore the potential of Artemisia absinthium compounds, particularly apigenin, as promising candidates for the development of new anti-leishmaniasis drugs. The potent inhibition of Leishmania NMT by apigenin, along with its favorable pharmacokinetic and stability profiles, supports its further exploration in antileishmanial drug development.

Quercetin inhibits Toxoplasma gondii tachyzoite proliferation and acts synergically with azithromycin

Quercetin (QUE) is a natural polyphenol known to have numerous pharmacological properties against infectious and non-infectious diseases. Azithromycin (AZ) is an antibiotic that belongs to the azalide class of antimicrobials and an antiparasitic that is known to be effective in combination with clindamycin against pyrimethamine/sulfadiazine-resistant Toxoplasma gondii tachyzoites in clinical settings. Both compounds are known to target protein synthesis and have anti-inflammatory properties. However, little is known about QUE and AZ synergistic interaction against T. gondii growth. Here, we report for the first time the effects of the combination of QUE and AZ on T. gondii growth. The 50% inhibitory concentration (IC50) for QUE at 72 h of interaction was determined to be 0.50 µM, whereas AZ gave an IC50 value of 0.66 µM at 72 h of interaction with parasites. Combination testing of QUE and AZ in a ratio of 2:1 (QUE:AZ) showed an IC50 value of 0.081 µM. Interestingly, a fractional inhibitory index value of 0.28 was observed, indicating a strong synergy. QUE was also found to upregulate the generation of reactive oxygen species and cause dysfunction of the mitochondria membrane of both intracellular and extracellular T. gondii tachyzoites. Overall, the results indicate that QUE is a novel lead capable of synergizing with AZ for inhibiting T. gondii growth and may merit future investigation in vivo for possible combination drug development.

Anti-Toxoplasma gondii activity of Trametes versicolor (Turkey tail) mushroom extract

Toxoplasma gondii (T. gondii) infection continues to rise globally in humans and animals with high socioeconomic and public health challenges. Current medications used against T. gondii infection are limited in efficacy, safety, and affordability. This research was conducted to assess the higher fungi extract effect on T. gondii tachyzoites growth in vitro and possibly decipher its mechanism of action. Furthermore, we evaluated the extract's effect on human foreskin fibroblast viability. The methanol extracts of Turkey tail (TT) mushroom was tested against T. gondii tachyzoites growth using an RH-RFP type I strain that expresses red fluorescent protein throughout culture in a dose-dependent manner using a fluorescent plate reader. Similarly, we tested the effect of the extract on host cell viability. We observed that TT extract inhibited tachyzoites growth with a 50% minimum inhibitory concentration (IC_50s), IC₅₀ = 5.98 ± 1.22 µg/mL, and 50% cytotoxic concentration (CC_50s), CC₅₀ ≥ 100 µg/mL. It was discovered that TT extract induced strong mitochondria superoxide and  reactive oxygen species production and disrupted mitochondria membrane potential in T. gondii tachyzoites. Additionally, scanning electron microscopy depicted that TT extract and pyrimethamine (PY) caused a morphological deformation of tachyzoites in vitro. In conclusion, TT methanol extract made up of phytosterols, bioactive sphingolipids, peptides, phenolic acids, and lactones could be a promising source of new compounds for the future development of anti-Toxoplasma gondii drugs. Extracts were non-cytotoxic, even at higher concentrations.

Engineered production of bioactive polyphenolic O-glycosides

Polyphenolic compounds (such as quercetin and resveratrol) possess potential medicinal values due to their various bioactivities, but poor water solubility hinders their health benefits to humankind. Glycosylation is a well-known post-modification method to biosynthesize natural product glycosides with improved hydrophilicity. Glycosylation has profound effects on decreasing toxicity, increasing bioavailability and stability, together with changing bioactivity of polyphenolic compounds. Therefore, polyphenolic glycosides can be used as food additives, therapeutics, and nutraceuticals. Engineered biosynthesis provides an environmentally friendly and cost-effective approach to generate polyphenolic glycosides through the use of various glycosyltransferases (GTs) and sugar biosynthetic enzymes. GTs transfer the sugar moieties from nucleotide-activated diphosphate sugar (NDP-sugar) donors to sugar acceptors such as polyphenolic compounds. In this review, we systematically review and summarize the representative polyphenolic O-glycosides with various bioactivities and their engineered biosynthesis in microbes with different biotechnological strategies. We also review the major routes towards NDP-sugar formation in microbes, which is significant for producing unusual or novel glycosides. Finally, we discuss the trends in NDP-sugar based glycosylation research to promote the development of prodrugs that positively impact human health and wellness.

Anti-Toxoplasma Activities of Some Egyptian Plant Extracts: An In Vitro Study

Purpose

Toxoplasmosis is a globally widespread parasitic disease which causes major health problems in human and animals. This research was conducted to assess the effect of some Egyptian herbal extracts against Toxoplasma gondii (T. gondii) tachyzoites in vitro.

Methods

The methanol extracts of Withania somnifera, Cyper rotundus, Acacia nilotica,Chrysanthemum cinerariae folium, Anethum graveolens, Raphanus sativus, Ceratonia siliqua, Elettaria cardamomum and Cuminum cyminum were tested against T. gondii tachyzoites.

Results

Among the tested plants, the extracts from Raphanus sativus, Cuminum cyminum, and Ceratonia siliqua exhibited high anti-Toxoplasma activities at 50 µg/ml, relative to sulfadiazine. They showed low IC50 values on T. gondii (7.92, 9.47 and 13.52 µg/ml, respectively) and high selectivity index values (100.79, 59.19, and 29.05, respectively). Scanning electron microscopy (SEM) findings indicated evident morphological changes in tachyzoites treated with these three herbal extracts.

Conclusion

Raphanus sativus, Ceratonia siliqua, and Cuminum cyminum methanol extracts could be promising sources of new medicament for toxoplasmosis.

Antimicrobial, Antivirulence, and Antiparasitic Potential of Capsicum chinense Jacq. Extracts and Their Isolated Compound Capsaicin

Bacterial, fungal, and parasitic infections increase morbimortality rates and hospital costs. This study aimed to assess the antimicrobial and antiparasitic activities of the crude extract from the seeds and peel of the pepper Capsicum chinense Jacq. and of the isolated compound capsaicin and to evaluate their ability to inhibit biofilm formation, eradicate biofilm, and reduce hemolysin production by Candida species. The crude ethanolic and hexane extracts were obtained by maceration at room temperature, and their chemical compositions were analyzed by liquid chromatography coupled to mass spectrometry (LC–MS). The antimicrobial activity of the samples was evaluated by determining the minimum inhibitory concentration. Inhibition of biofilm formation and biofilm eradication by the samples were evaluated based on biomass and cell viability. Reduction of Candida spp. hemolytic activity by the samples was determined on sheep blood agar plates. The antiparasitic action of the samples was evaluated by determining their ability to inhibit Toxoplasma gondii intracellular proliferation. LC–MS-ESI analyses helped to identify organic and phenolic acids, flavonoids, capsaicinoids, and fatty acids in the ethanolic extracts, as well as capsaicinoids and fatty acids in the hexane extracts. Antifungal action was more evident against C. glabrata and C. tropicalis. The samples inhibited biofilm formation and eradicated the biofilm formed by C. tropicalis more effectively. Sub-inhibitory concentrations of the samples significantly reduced the C. glabrata and C. tropicalis hemolytic activity. The samples only altered host cell viability when tested at higher concentrations; however, at non-toxic concentrations, they reduced T. gondii growth. In association with gold standard drugs used to treat toxoplasmosis, capsaicin improved their antiparasitic activity. These results are unprecedented and encouraging, indicating the Capsicum chinense Jacq. peel and seed extracts and capsaicin display antifungal and antiparasitic activities.

Moringa oleifera extract promotes apoptosis-like death in Toxoplasma gondii tachyzoites in vitro

Toxoplasma gondii is the causative agent of toxoplasmosis, and an important problem of public health. The current treatment for toxoplasmosis is the combination of pyrimethamine and sulphadiazine, which do not act in the chronic phase of toxoplasmosis and have several side-effects. This study evaluated the anti-T. gondii activity and potential mechanism of Moringa oleifera seeds’ aqueous extract in vitro. The concentration of M. oleifera extract in HeLa cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assays. The presence of T. gondii was assessed by quantitative polymerase chain reaction and toluidine blue staining. Pyrimethamine and sulphadiazine were used as drug controls. Modifications in T. gondii morphology and ultrastructure were observed by electron microscopy. In vitro, the M. oleifera extract had no toxic effect on HeLa cells at concentrations below 50 μg mL−1. Moringa oleifera extract inhibits T. gondii invasion and intracellular proliferation with similar results for sulphadiazine + pyrimethamine, and also shows cellular nitric oxide production at a concentration of 30 μg mL−1. Electron microscopy analyses indicated structural and ultrastructural modifications in tachyzoites after treatment. We also observed an increase in reactive oxygen species production and a loss of mitochondrial membrane integrity. Nile Red staining assays demonstrated a lipid accumulation. Annexin V–fluorescein isothiocyanate and propidium iodide staining demonstrated that the main action of M. oleifera extract in T. gondii tachyzoites was compatible with late apoptosis. In conclusion, M. oleifera extract has anti-T. gondii activity in vitro and might be a promising substance for the development of a new anti-T. gondii drug.