Anti-tyrosinase, anti-cholinesterase and cytotoxic activities of extracts and phytochemicals from the Tunisian Citharexylum spinosum L.: Molecular docking and SAR analysis

Ligand-Based Drug Design of Genipin Derivatives with Cytotoxic Activity against HeLa Cell Line: A Structural and Theoretical Study

Cervical cancer is a malignant neoplastic disease, mainly associated to HPV infection, with high mortality rates. Among natural products, iridoids have shown different biological activities, including cytotoxic and antitumor effects, in different cancer cell types. Geniposide and its aglycone Genipin have been assessed against different types of cancer. In this work, both iridoids were evaluated against HeLa and three different cervical cancer cell lines. Furthermore, we performed a SAR analysis incorporating 13 iridoids with a high structural similarity to Geniposide and Genipin, also tested in the HeLa cell line and at the same treatment time. Derived from this analysis, we found that the dipole moment (magnitude and direction) is key for their cytotoxic activity in the HeLa cell line. Then, we proceeded to the ligand-based design of new Genipin derivatives through a QSAR model (R2 = 87.95 and Q2 = 62.33) that incorporates different quantum mechanic molecular descriptor types (ρ, ΔPSA, ∆Polarizability2, and logS). Derived from the ligand-based design, we observed that the presence of an aldehyde or a hydroxymethyl in C4, hydroxyls in C1, C6, and C8, and the lack of the double bond in C7-C8 increased the predicted biological activity of the iridoids. Finally, ten simple iridoids (D9, D107, D35, D36, D55, D56, D58, D60, D61, and D62) are proposed as potential cytotoxic agents against the HeLa cell line based on their predicted IC50 value and electrostatic features.

Chemical constituents isolated from Actinidia polygama and their α-glucosidase inhibitory activity and insulin secretion effect

Actinidia polygama has been used as a traditional medicine for treating various diseases. In the present study, 13 compounds, including three new monoterpenoids (1-3), were isolated from the leaves of A. polygama to investigate the bioactive constituents of the plant. The structures were characterized by analyzing spectroscopic and chiroptical data. These compounds were preliminarily screened for their ability to increase insulin secretion levels after glucose stimulation. Of these, 3-O-coumaroylmaslinic acid (4) and jacoumaric acid (5) showed activity. In further biological studies, these compounds exhibited increased glucose-stimulated insulin secretion (GSIS) activity without cytotoxicity in rat INS-1 pancreatic β-cells as well as α-glucosidase inhibitory activity. Furthermore, both compounds increased insulin receptor substrate-2 (IRS-2), phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), pancreatic and duodenal homeobox-1 (PDX-1), and peroxisome proliferator-activated receptor-γ (PPAR-γ) expression. Hence, these compounds may be developed as potential antidiabetic agents.

Rhanteriol, a New Rhanterium suaveolens Desf. Lignan with Pharmacological Potential as an Inhibitor of Enzymes Involved in Neurodegeneration and Type 2 Diabetes

Several specialized plant metabolites are reported to be enzyme inhibitors. In this investigation, the phytochemical composition and the biological activity of Rhanterium suaveolens Desf. were studied. One new lignan (rhanteriol 1) and seven known secondary metabolites were isolated from the aerial parts of R. suaveolens by using different chromatographic procedures. The biological properties of the R. suaveolens extracts and the new compound were evaluated by measuring their ability to inhibit the cholinesterase and carbohydrate-hydrolyzing enzymes, using cell-free in vitro methods. The new lignan, rhanteriol, was shown to inhibit α-amylase and α-glucosidase (IC₅₀ = 46.42 ± 3.25 μM and 26.76 ± 3.29 μM, respectively), as well as butyrylcholinesterase (IC₅₀ = 10.41 ± 0.03 μM), with an effect comparable to that of the respective standards, acarbose and galantamine. Furthermore, docking studies were performed suggesting the interaction mode of rhanteriol with the active sites of the investigated enzymes. The obtained data demonstrated that the aerial part of R. suaveolens could represent a source of active molecules, such as rhanteriol, usable in the development of treatments for preventing or treating type 2 diabetes mellitus and neurodegeneration.

Leucosceptosides A and B: Two Phenyl-Ethanoid Glycosides with Important Occurrence and Biological Activities

In this review paper, the occurrence in the plant kingdom, the chemophenetic value and the biological activities associated with two specific phenyl-ethanoid glycosides, i.e., leucosceptoside A and leucosceptoside B, were reported. This is the first work ever conducted on such a subject. Analysis of the literature data clearly led to three important conclusions: leucosceptoside A is much more common in plants than leucosceptoside B; leucosceptoside A exerts more biological activities than leucosceptoside B even if nothing can be generally concluded about which one is actually the most potent; neither of these compounds can be used as a chemophenetic marker. These three aspects and more are discussed in more depth in this work.

A Network Pharmacology Analysis of Cytotoxic Triterpenes Isolated from Euphorbia abyssinica Latex Supported by Drug-likeness and ADMET Studies

Euphorbia plants have been identified as potential sources of antitumor lead compounds. The current study aimed to isolate and identify the main active constituents of Euphorbia abyssinica latex followed by a cytotoxic evaluation. A network pharmacology approach was employed to predict the underlying mechanism. Finally, drug-likeness and ADMET studies were conducted for active compounds. The phytochemical investigation of the latex of E. abyssinica resulted in the isolation of two triterpenes, 3-acetyloxy-(3α)-urs-12-en-28-oic methyl ester (1) and lup-20(29)-en-3α,23-diol (2). The dichloromethane extract displayed potent cytotoxic activity against the MCF7 cell line with an IC₅₀ value of 4.27 ± 0.12 μg/mL but weak activity against HepG2 and HeLa cell lines (IC₅₀ = 20.47 ± 1.17 and 26.73 ± 2.99 μg/mL, respectively) compared to doxorubicin. Compound 1 showed an encouraging cytotoxic effect against MCF7 with IC₅₀ = 4.20 ± 0.20 μg/mL, followed by compound 2 (IC₅₀ = 5.8 ± 0.35 μg/mL). The network analysis revealed that the two isolated compounds are linked to 68 targets of human nature, among which 51 genes are linked to breast carcinomas and 5 targets (AR, CYP19A1, EGFR, PGR, and PTGS2) might be the top therapeutic targets of isolated compounds on breast cancer. Furthermore, the gene-enrichment analysis revealed that E. abyssinica could play a role in the treatment of breast cancer by striking 51 potential targets via mainly three signaling pathways: P13K-AKT, Wnt, and VEGF. Therefore, isolated triterpenes could be considered effective antitumor agents for breast cancer by elucidating their candidate target to alleviate breast cancer and related signaling pathways of the targets.

Exploring the Synergistic Anticancer Potential of Benzofuran-Oxadiazoles and Triazoles: Improved Ultrasound- and Microwave-Assisted Synthesis, Molecular Docking, Hemolytic, Thrombolytic and Anticancer Evaluation of Furan-Based Molecules

Ultrasound- and microwave-assisted green synthetic strategies were applied to furnish benzofuran–oxadiazole 5a–g and benzofuran–triazole 7a–h derivatives in good to excellent yields (60–96%), in comparison with conventional methods (36–80% yield). These synthesized derivatives were screened for hemolysis, thrombolysis and anticancer therapeutic potential against an A549 lung cancer cell line using an MTT assay. Derivatives 7b (0.1%) and 5e (0.5%) showed the least toxicity against RBCs. Hybrid 7f showed excellent thrombolysis activity (61.4%) when compared against reference ABTS. The highest anticancer activity was displayed by the 5d structural hybridwith cell viability 27.49 ± 1.90 and IC₅₀ 6.3 ± 0.7 μM values, which were considerably lower than the reference drug crizotinib (IC₅₀ 8.54 ± 0.84 μM). Conformational analysis revealed the spatial arrangement of compound 5d, which demonstrated its significant potency in comparison with crizotinib; therefore, scaffold 5d would be a promising anticancer agent on the basis of cytotoxicity studies, as well as in silico modeling studies.

Non-Alkaloid Cholinesterase Inhibitory Compounds from Natural Sources

Alzheimer’s disease (AD) is a severe neurodegenerative disorder of different brain regions accompanied by distresses and affecting more than 25 million people in the world. This progressive brain deterioration affects the central nervous system and has negative impacts on a patient’s daily activities such as memory impairment. The most important challenge concerning AD is the development of new drugs for long-term treatment or prevention, with lesser side effects and greater efficiency as cholinesterases inhibitors and the ability to remove amyloid-beta(Aβ) deposits and other related AD neuropathologies. Natural sources provide promising alternatives to synthetic cholinesterase inhibitors and many have been reported for alkaloids while neglecting other classes with potential cholinesterase inhibition. This review summarizes information about the therapeutic potential of small natural molecules from medicinal herbs, belonging to terpenoids, coumarins, and phenolic compounds, and others, which have gained special attention due to their specific modes of action and their advantages of low toxicity and high efficiency in the treatment of AD. Some show superior drug-like features in comparison to synthetic cholinesterase inhibitors. We expect that the listed phytoconstituents in this review will serve as promising tools and chemical scaffolds for the discovery of new potent therapeutic leads for the amelioration and treatment of Alzheimer’s disease.

Two New Iridoid Glucosides from the Whole Plant of Patrinia scabiosifolia Link

As a traditional Chinese medicine, Patrinia scabiosifolia Link has been used to treat various inflammatory-related diseases, and recent studies have shown that it possesses potent anti-inflammatory activity. Therefore, phytochemical investigation on whole plants of P. scabiosifolia were carried out, which led to the isolation of two new iridoid glucosides, patriniscabiosides A (1) and B (2), together with six known compounds (3–8). The structural elucidation of all compounds was performed by HRESIMS and extensive spectroscopic analyses including IR, 1D, 2D NMR, and electronic circular dichroism (ECD). All the isolated compounds were tested for their anti-inflammatory activity using the NF-κB-Dependent Reporter Gene Expression Assay, and compound 3 displayed anti-inflammatory activity through the inhibition of the NF-κB pathway, with an inhibitory rate of 73.44% at a concentration of 10 μM.

Chemical Characterization, Antioxidant, Enzyme Inhibition and Antimutagenic Properties of Eight Mushroom Species: A Comparative Study

This study aimed to determine the chemical composition and biologic activities of eight mushroom species (Amanita crocea, Hemileccinum depilatum, Cyclocybe cylindracea, Lactarius deliciosus, Hygrocybe acutoconica, Neoboletus erythropus, Russula aurea and Russula sanguinea). The antioxidant, enzyme inhibitory and mutagenic/antimutagenic activities were evaluated to provide data on the biologic activities. With respect to the chemical composition, LC-MS/MS technique was used to determine individual phenolic compounds present in the extracts. Antioxidant properties were investigated by different chemical methods including radical quenching (DPPH and ABTS), reducing power (CUPRAC and FRAP), phosphomolybdenum and metal chelating. In the enzyme inhibitory assays, cholinesterases, tyrosinase, amylase and glucosidase were used. Mutagenic and antimutagenic properties were evaluated by the Ames assay. In general, the best antioxidant abilities were observed from H. depilatum and N. erythropus, which also showed highest level of phenolics. The best cholinesterase inhibition ability was found from C. cylindracea (1.02 mg GALAE/g for AChE; 0.99 mg GALAE/g for BChE). Tyrosinase inhibition ability varied from 48.83 to 54.18 mg KAE/g. The extracts exhibited no mutagenic effects and showed significant antimutagenic potential. H. acutoconica, in particular depicted excellent antimutagenicity with a ratio of 97% for TA100 and with a rate of 96% for TA98 strain against mutagens in the presence of metabolic activation system. Results presented in this study tend to show that the mushroom species could be exploited as potential sources of therapeutic bioactive agents, geared towards the management of oxidative stress, global health problems and cancer.