In silico and in vitro comparative activity of green tea components against Leishmania infantum

New Mechanism for the Apoptosis of Human Neuroblastoma Cells by the Interaction between Fluorene-9-Bisphenol and the G Protein-Coupled Estrogen Receptor 1

Fluorene-9-bisphenol (BHPF) is an emerging contaminant. Presently, there is no report on its interaction with G protein-coupled estrogen receptor 1 (GPER). By using an integrated toxicity research scenario that combined theoretical study with experimental methods, BHPF was found to inhibit the GPER-mediated effect via direct receptor binding. Molecular dynamics simulations found that Trp2726.48 and Glu2756.51 be the key amino acids of BHPF binding with GPER. Moreover, the calculation indicated that BHPF was a suspected GPER inhibitor, which neither can activate GPER nor is able to form water channels of GPER. The role of two residues was successfully verified by following gene knockout and site-directed mutagenesis assays. Further in vitro assays showed that BHPF could attenuate the increase in intracellular concentration of free Ca2+ induced by G1-activated GPER. Besides, BHPF showed an enhanced cytotoxicity compared with G15, indicating that BHPF might be a more potent GPER inhibitor than G15. In addition, a statistically significant effect on the mRNA level of GPER was observed for BHPF. In brief, the present study proposes that BHPF be a GPER inhibitor, and its GPER molecular recognition mechanism has been revealed, which is of great significance for the health risk and assessment of BHPF.

Antiparasitic effect of Farnesol against Leishmania major: A rationale from in vitro and in silico investigations

Leishmaniasis is a vector-borne parasitic infection caused by the infective bite of female Phlebotomine sandflies. Treatment of leishmaniasis by conventional synthetic compounds is met by challenges pertaining to adverse effects which call for the discovery of newer anti-leishmanial molecules. This study was performed to evaluate the effect and modes of action of a sesquiterpene alcoholic molecule Farnesol on Leishmania major, the causative agent of Zoonotic CL. The cytotoxic effect of Farnesol against L.major promastigotes, amastigotes and macrophages was assessed by MTT test and counting. The IC50 on promastigotes by Farnesol on L.major was also evaluated by flow cytometry. In the findings, promastigotes were reduced at 167μM. The mean numbers of L.major amastigotes in macrophages were significantly decreased on exposure to Farnesol at 172μM. In addition, Farnesol induced significant apoptosis dose-dependent on L.major promastigotes. In silico protein-ligand_binding analyses indicated the effect of Farnesol in perturbation of the ergosterol synthesis pathway of Leishmania with attributes suggesting inhibition of Lanosterol-α-demethylase, the terminal enzyme of ergosterol synthesis machinery. Findings from flow cytometry reveal the role of Farnesol in apoptosis-induced killing in promastigotes. Farnesol was effective at very lower concentrations when compared to Paromomycin. Further studies are crucial to evaluate the therapeutic potential of Farnesol alone or in combination with other conventional drugs in animal models.

In vitro and in silico scolicidal effect of sanguinarine on the hydatid cyst protoscoleces

We aimed to investigate the scolicidal effects of sanguinarine on hydatid cyst protoscoleces (PSCs) in vitro and in silico. Different targets were docked into the active sites of sanguinarine. Molecular docking processes and visualization of interactions were performed using AutoDock Vina and Discovery Studio Visualizer. Binding energy was calculated and compared (kcal/mol). PSCs were aspirated from the hydatid cysts and washed. The sediments of PSCs were then exposed to various concentrations (50, 25, 12, 6, 3, and 1 μg/mL) of sanguinarine. The viability test was finally evaluated by the Trypan blue solution 4%. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPX), and catalase were analyzed to assess the level of oxidative stress-treated PSCs. Caspase-3 activity rate was determined to evaluate cell apoptosis in treated PSCs. Among the receptors, acetylcholinesterase was identified as the excellent target, with Vina score of -11.8. Sanguinarine showed high scolicidal effects after 12, 24, and 48 h. Also, in the first hour of exposure to the drug, caspase-3 activity and MDA level significantly increased, but the levels of GSH and GPx had a significant reduction after 12, 24, and 48 h (P < 0.05). The findings of this study revealed that sanguinarine have potent scolicidal effects in vitro and in silico and could be considered an opportunity for the introduction of a novel and safe therapeutic agent for the treatment of cystic echinococcosis. However, supplementary studies will be desired to prove the current findings by examining sanguinarine in a clinical setting.

Investigation of the Potential Targets behind the Promising and Highly Selective Antileishmanial Action of Synthetic Flavonoid Derivatives

Leishmaniases are among the neglected tropical diseases that still cause devastating health, social, and economic consequences to more than 350 million people worldwide. Despite efforts to combat these vector-borne diseases, their incidence does not decrease. Meanwhile, current antileishmanial drugs are old and highly toxic, and safer presentations are unaffordable to the most severely affected human populations. In a previous study by our research group, we synthesized 17 flavonoid derivatives that demonstrated impressive inhibition capacity against rCPB2.8, rCPB3, and rH84Y. These cysteine proteases are highly expressed in the amastigote stage, the target form of the parasite. However, although these compounds have been already described in the literature, until now, the amastigote effect of any of these molecules has not been proven. In this work, we aimed to deeply analyze the antileishmanial action of this set of synthetic flavonoid derivatives by correlating their ability to inhibit cysteine proteases with the action against the parasite. Among all the synthesized flavonoid derivatives, 11 of them showed high activity against amastigotes of Leishmania amazonensis, also providing safety to mammalian host cells. Furthermore, the high production of nitric oxide by infected cells treated with the most active cysteine protease B (CPB) inhibitors confirms a potential immunomodulatory response of macrophages. Besides, considering flavonoids as multitarget drugs, we also investigated other potential antileishmanial mechanisms. The most active compounds were selected to investigate another potential biological pathway behind their antileishmanial action using flow cytometry analysis. The results confirmed an oxidative stress after 48 h of treatment. These data represent an important step toward the validation of CPB as an antileishmanial target, as well as aiding in new drug discovery studies based on this protease.

Green Tea (Camellia sinensis): A Review of Its Phytochemistry, Pharmacology, and Toxicology

Objectives Green tea (Camellia sinensis) is a kind of unfermented tea that retains the natural substance in fresh leaves to a great extent. It is regarded as the second most popular drink in the world besides water. In this paper, the phytochemistry, pharmacology, and toxicology of green tea are reviewed systematically and comprehensively. Key findings Green tea has been demonstrated to be good for human health. Nowadays, multiple pharmacologically active components have been isolated and identified from green tea, including tea polyphenols, alkaloids, amino acids, polysaccharides, and volatile components. Recent studies have demonstrated that green tea shows versatile pharmacological activities, such as antioxidant, anticancer, hypoglycemic, antibacterial, antiviral, and neuroprotective. Studies on the toxic effects of green tea extract and its main ingredients have also raised concerns including hepatotoxicity and DNA damage. Summary Green tea can be used to assist the treatment of diabetes, Alzheimer’s disease, oral cancer, and dermatitis. Consequently, green tea has shown promising practical prospects in health care and disease prevention.

Synthesis of Tellurium Oxide (TeO2) Nanorods and Nanoflakes and Evaluation of Its Efficacy Against Leishmania major In Vitro and In Vivo

PURPOSE

Today, the use of natural products and nanostructures has increased. Given the reports on beneficial effects of various organotellurane compounds on types of visceral leishmaniasis, we decided to investigate the effect of TeO₂ NPs on Leishmania major (L. major). Tellurium can cause cell apoptosis in cancer cells without activating the caspase-pathway.

METHODS

TeO₂ NPs at first synthesized and the structure was checked by XRD, SEM and EDS tests. The cytotoxic effect of TeO₂ NPs against L. major promastigotes, amastigotes and macrophages was assessed by MTT test or counting. The possible apoptosis of L. major by TeO₂ NPs was evaluated by flow cytometry test. For in vivo assay, the lesions of infected BALB/c mice with L. major promastigotes were treated with TeO₂ NPs, then the lesion size and survival rate were evaluated.

RESULTS

The synthesis of TeO₂ with tetragonal structure was confirmed by XRD. The combination of nanorods and nanoflakes and the presence of Te were proven by SEM and EDS, respectively. According the effects of nanoparticle on promastigotes and amastigotes, the IC₅₀ values of TeO₂ after 72 h of incubation were 15.13 and 52.22 µg/ml, respectively. TeO₂ NPs induced apoptosis in about 41% of promastigotes. The ulcer greatly healed and survival rate was higher in treated mice compared to those in control group.

CONCLUSION

Based on the data, favorable anti-leishmanial properties were observed by using TeO₂ NPs. TeO₂ NPs have cytotoxic impacts on L. major promastigotes and amastigotes in vitro and in vivo and may be regarded as a therapy option.

Comparison of the Effects of Sambucus ebulus Leaf and Fruit Extracts on Leishmania major In Vitro

BACKGROUND

Leishmaniasis is one of the major diseases caused by the intracellular parasite of Leishmania. It has become one of the most dangerous health problems today. Our aim of the present study is to compare the effects of Sambucus ebulus leaf and fruit extracts on Leishmania major in vitro.

METHODS

In this study, we used MTT, promastigote and amastigote assay to evaluate the effect of different concentrations of the extract on parasite and we compared their effects. The flow cytometry technique was also used to detect the apoptotic effect of the extracts on promastigotes.

RESULTS

According to MTT experiment IC₅₀ concentration of leaf and fruit extracts on parasite was 157 μg/ml and 265 μg/ml, respectively. After analysis by flow cytometry, leaf and fruit extracts also showed the apoptosis effect. Leaf and fruit extract caused 40.2 and 2.67 percent apoptosis.

CONCLUSION

Based on the above assessment, we determined that the S. ebulus leaf extract has a more toxic effect on promastigotes and amstigotes than its fruit extract and maybe in the future that be used as a drug candidate.

Identification of 3-Methoxycarpachromene and Masticadienonic Acid as New Target Inhibitors against Trypanothione Reductase from Leishmania Infantum Using Molecular Docking and ADMET Prediction

Polyphenolic and Terpenoids are potent natural antiparasitic compounds. This study aimed to identify new drug against Leishmania parasites, leishmaniasis’s causal agent. A new in silico analysis was accomplished using molecular docking, with the Autodock vina program, to find the binding affinity of two important phytochemical compounds, Masticadienonic acid and the 3-Methoxycarpachromene, towards the trypanothione reductase as target drugs, responsible for the defense mechanism against oxidative stress and virulence of these parasites. There were exciting and new positive results: the molecular docking results show as elective binding profile for ligands inside the active site of this crucial enzyme. The ADMET study suggests that the 3-Methoxycarpachromene has the highest probability of human intestinal absorption. Through this work, 3-Methoxycarpachromene and Masticadienonic acid are shown to be potentially significant in drug discovery, especially in treating leishmaniasis. Hence, drug development should be completed with promising results.

Scanning electron microscopy of Sophora alopecuroides L. seeds and their cytotoxic, antimicrobial, antioxidant, and enzyme inhibition potentials

Sophora alopecuroides L. is a highly medicinal plant. The aim of the current study was to determine the phytochemical screening, pharmacological potentials and application of scanning electron microscope (SEM) of S. alopecuroides (SA) seeds. To achieve this purpose, six different solvents were used to prepare SA seed extracts. Phytochemical and antioxidant activities were determined calorimetrically. To investigate the antidiabetic activity, α-amylase inhibition assay was determined. Brine shrimp assay was used to determine cytotoxicity potential. Anti-leishmanial potential was confirmed using MTT assay. Disc-diffusion method was used to detect protein kinase inhibitory, antibacterial and antifungal activities and showed significant results. SEM analysis was used as an identification tool. Considerable amount of phenolic and flavonoid contents were identified in methanol extract (SASM) (93.76 ± 2.71 GAE/mg) and (77 ± 3.60 QE/mg). Highest DPPH scavenging potential (82%) was reported for SASM. Significant total antioxidant capacity (90.60 ± 1.55 alpha amylase enzyme [AAE]/mg) and total reducing power (94.44 ± 1.38 AAE/mg) were determined for LOSM. Highest α-amylase inhibition was reported in SASM (78.20 ± 1.58%). Highest LD₅₀ of brine shrimp was found for n-hexane extract (SASH) 13.03 μg/ml. All extracts showed strong anti-leishmanial activity except SASH. The seeds of SA were seen to be oblong to obovate, projections, wavy slightly straight, anticlinal wall was raised with apex acuminate. In conclusion, our experimental findings highly support the ethnomedicinal and biological potentials of the SA seeds. Moreover, SA seeds need to be explored for identification and isolation of bioactive compounds. In future, we recommend further in vivo toxicity assays and clinical efficacies to further evaluate its different biomedical properties.

Unveiling the Targets Involved in the Quest of Antileishmanial Leads Using In silico Methods

BACKGROUND

Leishmaniasis is a neglected tropical disease associated with several clinical manifestations, including cutaneous, mucocutaneous, and visceral forms. As currently available drugs have some limitations (toxicity, resistance, among others), the target-based identification has been an important approach to develop new leads against leishmaniasis. The present study aims to identify targets involved in the pharmacological action of potent antileishmanial compounds.

METHODS

The literature information regarding molecular interactions of antileishmanial compounds studied over the past half-decade is discussed. The information was obtained from databases such as Wiley, SciFinder, Science Direct, National Library of Medicine, American Chemical Society, Scientific Electronic Library Online, Scopus, Springer, Google Scholar, Web of Science, etc. Results: Numerous in vitro antileishmanial compounds showed affinity and selective interactions with enzymes such as arginase, pteridine reductase 1, trypanothione reductase, pyruvate kinase, among others, which are crucial for the survival and virulence of the Leishmania parasite.

CONCLUSION

The in-silico activity of small molecules (enzymes, proteins, among others) might be used as pharmacological tools to develop candidate compounds for the treatment of leishmaniasis. As some pharmacologically active compounds may act on more than one target, additional studies of the mechanism (s) of action of potent antileishmanial compounds might help to better understand their pharmacological action. Also, the optimization of promising antileishmanial compounds might improve their biological activity.

Natural Products That Target the Arginase in Leishmania Parasites Hold Therapeutic Promise

Parasites of the genus Leishmania cause a variety of devastating and often fatal diseases in humans worldwide. Because a vaccine is not available and the currently small number of existing drugs are less than ideal due to lack of specificity and emerging drug resistance, the need for new therapeutic strategies is urgent. Natural products and their derivatives are being used and explored as therapeutics and interest in developing such products as antileishmanials is high. The enzyme arginase, the first enzyme of the polyamine biosynthetic pathway in Leishmania, has emerged as a potential therapeutic target. The flavonols quercetin and fisetin, green tea flavanols such as catechin (C), epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin-3-gallate (EGCG), and cinnamic acid derivates such as caffeic acid inhibit the leishmanial enzyme and modulate the host’s immune response toward parasite defense while showing little toxicity to the host. Quercetin, EGCG, gallic acid, caffeic acid, and rosmarinic acid have proven to be effective against Leishmania in rodent infectivity studies. Here, we review research on these natural products with a focus on their promise for the development of treatment strategies as well as unique structural and pharmacokinetic/pharmacodynamic features of the most promising agents.

Catechins as Model Bioactive Compounds for Biomedical Applications

Research regarding polyphenols has gained prominence over the years because of their potential as pharmacological nutrients. Most polyphenols are flavanols, commonly known as catechins, which are present in high amounts in green tea. Catechins are promising candidates in the field of biomedicine. The health benefits of catechins, notably their antioxidant effects, are related to their chemical structure and the total number of hydroxyl groups. In addition, catechins possess strong activities against several pathogens, including bacteria, viruses, parasites, and fungi. One major limitation of these compounds is low bioavailability. Catechins are poorly absorbed by intestinal barriers. Some protective mechanisms may be required to maintain or even increase the stability and bioavailability of these molecules within living organisms. Moreover, novel delivery systems, such as scaffolds, fibers, sponges, and capsules, have been proposed. This review focuses on the unique structures and bioactive properties of catechins and their role in inflammatory responses as well as provides a perspective on their use in future human health applications.

Antimicrobial, cytotoxic, antioxidants, enzyme inhibition activities, and scanning electron microscopy of Lactuca orientalis (Boiss.) Boiss. seeds

Lactuca orientalis (Boiss.) Boiss. is one of the most frequently used ethnomedicinal plant. This research study was designed to decipher the phytochemical screening, pharmacological potential and implementation of scanning electron microscope (SEM). Six different solvents were used to prepare L. orientalis (LO) seed extracts. Phytochemical and antioxidant activities were determined calorimetrically. To investigate antidiabetic, α-amylase inhibition assay was performed. Brine shrimp assay was performed for cytotoxicity and anti-leishmanial via MTT assay. Disc-diffusion assay was performed to detect protein kinase inhibitory, antibacterial and antifungal activities. SEM was used as identification tool. Significant amount of phenolic and flavonoid content were identified in methanol extract (LOSM) (95.76 ± 3.71 GAE/mg) and (77 ± 3.60 QE/mg). Highest DPPH scavenging potential (82%) was reported for LOSM. Significant total antioxidant capacity (90.60 ± 1.55 AAE/mg) and total reducing power (94.44 ± 1.38 AAE/mg) were determined for LOSM. Highest α-amylase inhibition was found in LOSM (78.20 ± 1.58%). The highest LD₅₀ of brine shrimp was found for n-Hexane extract (LOSH) 13.03 𝜇g/ml. All extracts showed strong anti-leishmanial activity except LOSH. L. orientalis seeds showed significant protein kinase inhibition, antibacterial and antifungal activities. The seeds of L. orientalis were seen to be oblong to obovate, projections, wavy slightly straight, anticlinal wall was raised with apex acuminate. The outer-periclinal wall convex with fine texture. In conclusion, our findings scientifically support ethnomedicinal and biological potentials of L. orientalis seeds. In future, L. orientalis seeds need to be explored for identification and isolation of bioactive compounds. The results obtained necessitate further in vivo studies to evaluate their pharmacological potentials.