RESUMEN

Alzheimer's Disease (AD) is a fatal age-related neurodegenerative condition with a multifactorial etiology contributing to 70% of dementia globally. The search for a multi-target agent to hit different targets involved in the pathogenesis of AD is crucial. In the present study, the neuroprotective effects of four Morus extracts were assessed in LPS-induced AD in mice. Among the studied species, M. macroura exhibited a profound effect on alleviating the loss of cognitive function, improved the learning ability, restored the acetylcholine esterase (AChE) levels to normal, and significantly reduced the tumor necrosis factor alpha (TNF-α) brain content in LPS-treated mice. To investigate the secondary metabolome of the studied Morus species, ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-HRMS/MS), aided with feature-based molecular networking, was employed. Among the annotated features, aryl benzofurans and prenylated flavonoids were suggested as being responsible for the observed neuroprotective effect. Furthermore, some of the detected metabolites were proposed as new natural products such as moranoline di-O-hexoside (1), isomers of trimethoxy-dihydrochalcone-O-dihexoside (59 & 76), (hydroxy-dimethoxyphenyl)butenone-O-hexoside (82), and O-methylpreglabridin-O-sulphate (105). In conclusion, our findings advocate the potential usage of M. macroura leaves for the management of AD, yet after considering further clinical trials.

Asunto(s)

RESUMEN

Centaurea is a genus compromising over 250 herbaceous flowering species and is used traditionally to treat several ailments. Among the Egyptian Centaurea species, C. lipii was reported to be cytotoxic against multidrug-resistant cancer cells. In this context, we aimed to explore the metabolome of C. lipii and compare it to other members of the genus in pursuance of identifying its bioactive principles. An LC-MS/MS analysis approach synchronized with feature-based molecular networks was adopted to offer a holistic overview of the metabolome diversity of the Egyptian Centaurea species. The studied plants included C. alexandrina, C. calcitrapa, C. eryngioides, C. glomerata, C. lipii, C. pallescens, C. pumilio, and C. scoparia. Their constitutive metabolome showed diverse chemical classes such as cinnamic acids, sesquiterpene lactones, flavonoids, and lignans. Linking the recorded metabolome to the previously reported cytotoxicity identified sesquiterpene lactones as the major contributors to this activity. To confirm our findings, bioassay-guided fractionation of C. lipii was adopted and led to the isolation of the sesquiterpene lactone cynaropicrin with an IC50 of 1.817 µM against the CCRF-CEM leukemia cell line. The adopted methodology highlighted the uniqueness of the constitutive metabolome of C. lipii and determined the sesquiterpene lactones to be the responsible cytotoxic metabolites.

Asunto(s)

RESUMEN

The genus Centaurea is recognized in folk medicine for anti-inflammatory, anti-itch, antitussive, purgative, astringent, and tonic activities. To study the chemical determinant for antimicrobial activity essential oils (EOs), five Centaurea species were analyzed including: C. scoparia, C. calcitrapa, C. glomerata, C. lipii and C. alexandrina. Conventional hydro-distillation (HD) and microwave-assisted extraction (MAE), as new green technologies, were compared for the extraction of essential oils. GC/MS analysis identified 120 EOs including mostly terpenoid except from C. lipii and C. alexandrina in which nonterpenoids were the major constituents. Major terpenoids included spathulenol, caryophyllene oxide and alloaromadendrene oxide-2. To probe antibacterial activity, potential EO inhibitors of a bacterial type II DNA topoisomerase, DNA gyrase B were screened via an in silico molecular docking approach. Spathulenol and alloaromadendrene oxide-2 possessed the best binding affinity in the ATP- binding pocket of Gyrase B enzyme. Principal component analysis and agglomerative hierarchical clustering were used for sample classification and revealed that sesquiterpenes contributed the most for accessions classification. In vitro antimicrobial activity against Staphylococcus aureus, Escherichia coli and Aspergillus niger for all EOs were also evaluated. EOs from C. lipii, C. glomerata and C. calcitrapa exhibited significant MIC against S. aureus with an MIC value of 31.25 µg/mL.

RESUMEN

BACKGROUND: The multidrug resistance (MDR) phenotype encounters a major challenge to the success of established chemotherapy in cancer patients. We hypothesized that cytotoxic medicinal plants with novel phytochemicals can overcome MDR and kill MDR-cells with similar efficacy as drug sensitive cells. PURPOSE: We evaluated plant extracts from an unexplored ecosystem in Egypt with unusual climate and nutrient conditions for their activity against sensitive and multidrug-resistant cancer cell lines. MATERIAL AND METHODS/STUDY DESIGN: Methylene chloride: methanol (1:1) and methanol: H2O (7:3) extracts of 40 plants were prepared resulting in a sum of 76 fraction containing compounds with varying polarity. The resazurin reduction assay was employed to evaluate the cytotoxicity of these extracts on five matched pairs of drug-sensitive and their drug-resistant cell lines. Flow cytometry and Western blotting was used to determine cell cycle analyses, apoptosis, and autophagy. Reactive oxygen species (ROS) were measured spectrophotometrically. RESULTS: Extracts derived from Withania obtusifolia (WO), Jasonia candicans (JC), Centaurea lippii (CL), and Pulicaria undulata (PU) were the most active ones among 76 extracts from 40 Egyptian medicinal plants. They showed a significant reduction of cell viability on drug-sensitive CCRF-CEM leukemia cell line with IC50 values less than 7 µg/ml. Low cross-resistance degrees were observed in multidrug-resistant CEM/ADR5000 cells towards CL (1.82-fold) and JC (6.09-fold). All other drug-resistant cell lines did not reveal cross-resistance to the four extracts. Further mechanistic assessment have been studied for these four extracts. CONCLUSION: The methylene chloride: methanol (1:1) fractions of WO, JC, CL, and PU are promising cytotoxic extracts that could be used to combat MDR cancer cells through different cell death pathways.

Asunto(s)

RESUMEN

Euphorbia species are rich in diterpenes. A solvent extraction of Euphorbia sanctae-catharinae, a species indigenous to the Southern Sinai of Egypt, afforded several premyrsinane diterpenoids (1⁻4) as well as previously reported metabolites (5⁻13) that included three flavonoids. Isolated compounds were chemically characterized by spectroscopic analysis. Identified compounds were bioassayed for anti-proliferative activity in vitro against colon (Caco-2) and lung (A549) tumor cell lines. Compound 9 exhibited robust anti-proliferative activity against A549 cells (IC50 = 3.3 µM). Absolute configurations for 8 versus 9 were determined by experimental and TDDFT-calculated electronic circular dichorism (ECD) spectra.

Asunto(s)

RESUMEN

Marine invertebrates including sponges, soft coral, tunicates, mollusks and bryozoan have proved to be a prolific source of bioactive natural products. Among marine-derived metabolites, terpenoids have provided a vast array of molecular architectures. These isoprenoid-derived metabolites also exhibit highly specialized biological activities ranging from nerve regeneration to blood-sugar regulation. As a result, intense research activity has been devoted to characterizing invertebrate terpenes from both a chemical and biological standpoint. This review focuses on the chemistry and biology of terpene metabolites isolated from the Red Sea ecosystem, a unique marine biome with one of the highest levels of biodiversity and specifically rich in invertebrate species.

Asunto(s)

RESUMEN

Natural products are structurally and biologically interesting metabolites, but they have been isolated in minute amounts. The syntheses of such natural products help in obtaining them in bulk amounts. The recognition of microbial biotransformation as important manufacturing tool has increased in chemical and pharmaceutical industries. In recent years, microbial transformation is increasing significantly from limited interest into highly active area in green chemistry including preparation of pharmaceutical products. This is the first review published on the usage of microbial biocatalysts for some natural product classes and natural product drugs.