Isolation and Structural Characterization of Specific Bacterial β-Glucuronidase Inhibitors from Noni (Morinda citrifolia) Fruits

Sesquilignans: Current research and potential prospective

Lignans are widely distributed in nature, primarily found in the xylem and resins of plants, with the constituent units C6-C3, and their dimers are the most common in plants. In recent years, the trimeric sesquilignans have also received increasing attention from scholars. More than 200 derivatives have been isolated and identified from nearly 50 families, most of which are different types (monoepoxy lignans, bisepoxy lignans, benzofuran lignans) connected with simple phenylpropanoids through ether bonds, C-C bonds, and oxygen-containing rings to constitute sesquilignans. Some of them also possess pharmacological properties, including antioxidants, hepatoprotectives, antitumors, anti-inflammatory properties, and other properties. In addition, the chemical structure of sesquilignans is closely related to the pharmacological activity, and chemical modification of methoxylation enhances the pharmacological activity. In contrast, phenolic hydroxyl and hydroxyl glycosides reduce the pharmacological activity. Therefore, the present review aims to summarize the chemical diversity, bioactivities, and constitutive relationships to provide a theoretical basis for the more profound development and utilization of sesquilignans.

Astraoleanosides E-P, oleanane-type triterpenoid saponins from the aerial parts of Astragalus membranaceus Bunge and their β-glucuronidase inhibitory activity

Historically, Astragalus membranaceus Bunge has been used as a beneficial medicinal plant, particularly in the Asian traditional medical systems, for the treatment of various human diseases such as stomach ulcers, diarrhea, and respiratory issues associated with phlegm. In this study, a phytochemical characterization of the aerial parts of A. membranaceusled to the isolation of 29 oleanane-type triterpenoid saponins, including 11 new compounds named astraoleanosides E-P (6-9, 13, 14, 18-22), as well as 18 known ones. The structures of these compounds were elucidated using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. Among them, astraoleanoside H (9) and cloversaponin III (15) demonstrated the most potent β-glucuronidase inhibitory activities, with IC50 values of 21.20 ± 0.75 and 9.05 ± 0.47 µM, respectively, compared to the positive control d-saccharic acid 1,4-lactone (IC50 = 20.62 ± 1.61 µM). Enzyme kinetics studies were then conducted to investigate the type of inhibition exhibited by these active compounds. In addition, the binding mechanism, key interactions, binding stability, and dynamic behavior of protein-ligand complexes were investigated through in silico approaches, such as molecular docking and molecular dynamics simulations. These findings highlight the promising potential of triterpenoid saponins from A. membranaceus as lead compounds for β-glucuronidase inhibitors, offering new possibilities for the development of therapeutic agents targeting various diseases where β-glucuronidase plays a crucial role.

Effect of Morinda citrifolia fruit powder on physiological and productive performance of Cavia porcellus

The breeding of guinea pig is part of the pluriactivity for millions of farming families in rural areas from the Peruvian Andean and Amazonian regions and other South American Andean countries. Rearing these specie plays an important source of employment, income, and nutrition for millions of rural families on these countries. The search of natural products for enhancing animal wellbeing, health, and production and thereby of guinea pigs is being searched nowadays. The aim of this study was to determine the effect of the ripe fruit powder of Morinda citrifolia on the physiological and productive performance parameters of reared guinea pigs under humid tropical conditions and to find a new use of noni fruit and to improve the guinea pig as an agrifood product. For this purpose, forty-eight male Peru breed guinea pigs sixty days old, were used and distributed into four treatments with diets containing 0, 2, 4 and 8% of the noni ripe fruit powder, with four replicates and 3 guinea pigs each. Erythrocytes, hematocrit, hemoglobin profiles, hematological indices MCV (mean cell volume), MCHC (mean corpuscular hemoglobin concentration), MCH (mean corpuscular hemoglobin) and blood metabolites profiles: TP (total protein), ALB (albumin), GLO (globulin), TC (total cholesterol) were determined. The productive performance indices: DWG (daily weight gain), DCFI (daily concentrated feed intake), TFIFM (total feed intake of fresh matter) and TFIDM (total feed intake of dry matter), FRCFM (feed rate conversion for fresh mater) and FRCDM (feed rate conversion for dry matter) were evaluated. The guinea pigs were evaluated at 60, 75 and 90 days old. The interaction between noni fruit powder and the age of guinea pigs produced an increase in the erythrocyte, hematocrit, MCH and MCHC levels at 75 days old, (p < 0.05). The final weight and the daily weight gain increased, while the feed rate conversion for fresh and dry matter decreased, as the level of noni fruit powder in the diet increased until 4% (p < 0.05). Thus, the level of noni ripe fruit powder in the guinea pigs' diets had a positive effect on the erythrocyte, leucocytes, hematocrit, MCH, MCHC levels, the final weight, the daily weight gain, and the feed rate conversion of fresh and dry matter.

Bisabolane-type sesquiterpenoids with potential anti-inflammatory and anti-HIV activities from the stems and leaves of Morinda citrifolia

The phytochemical study on the stems and leaves of Morinda citrifolia L. resulted in the isolation of a new naturally occurring bisabolane-type sesquiterpenoid, morincitrinoid A (1), together with five known analogues (2-6). The chemical structure of 1 was elucidated by comprehensive spectral analyses. The known compounds 2-6 were identified by comparing their spectral data with those reported in the literature, which were isolated from M. citrifolia for the first time. In addition, the anti-inflammatory and anti-HIV activities of compounds 1-6 were evaluated in vitro. Compounds 1-6 displayed significant inhibitory activities on NO (nitric oxide) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells with IC₅₀ values ranging from 0.98 ± 0.07 to 6.32 ± 0.11 μM, which was comparable to hydrocortisone. Meanwhile, compounds 1-6 showed remarkable anti-HIV-1 reverse transcriptase (RT) effects with the EC₅₀ values ranging from 0.16 to 6.29 μM.

Anthraquinones with potential antiproliferative activities from the fruits of Morinda citrifolia

The phytochemical investigation on the fruits of Morinda citrifolia led to the isolation and characterization of a new anthraquinone, moricitrifone (1), along with seven known anthraquinones (2-8). The chemical structure of 1 was elucidated by extensive spectral analyses. The known compounds (2-8) were identified by comparing their spectral data with those reported in the literature. The antiproliferative activities of all isolated anthraquinones (1-8) against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 were evaluated in vitro. Compounds 1-8 exhibited remarkable antiproliferative activities with IC₅₀ values ranging from 0.26 ± 0.05 to 16.58 ± 0.18 μM, which were comparable to those of doxorubicin.

Two new 2-phenylethylchromones from artificial agarwood by holing method

Two new 2-(2-phenylethyl)chromone derivatives (1-2) were isolated from the ethyl acetate extract of artificial agarwood induced by holing method originating from Aquilaria sinensis (Lour.) Gilg, and they were isolated from this genus for the first time. The structures of these two new compounds were elucidated by extensive spectroscopic analyses, including UV, IR, one- and two-dimensional NMR and HRESIMS measurements. Bioassay tests of these two new compounds showed compounds 1 and 2 had weak inhibitory activity against acetylcholinesterase at a concentration of 50.0 μg/ml.

Microbiota-Host-Irinotecan Axis: A New Insight Toward Irinotecan Chemotherapy

Irinotecan (CPT11) and its active metabolite ethyl-10-hydroxy-camptothecin (SN38) are broad-spectrum cytotoxic anticancer agents. Both cause cell death in rapidly dividing cells (e.g., cancer cells, epithelial cells, hematopoietic cells) and commensal bacteria. Therefore, CPT11 can induce a series of toxic side-effects, of which the most conspicuous is gastrointestinal toxicity (nausea, vomiting, diarrhea). Studies have shown that the gut microbiota modulates the host response to chemotherapeutic drugs. Targeting the gut microbiota influences the efficacy and toxicity of CPT11 chemotherapy through three key mechanisms: microbial ecocline, catalysis of microbial enzymes, and immunoregulation. This review summarizes and explores how the gut microbiota participates in CPT11 metabolism and mediates host immune dynamics to affect the toxicity and efficacy of CPT11 chemotherapy, thus introducing a new concept that is called "microbiota-host-irinotecan axis". Also, we emphasize the utilization of bacterial β-glucuronidase-specific inhibitor, dietary interventions, probiotics and strain-engineered interventions as emergent microbiota-targeting strategies for the purpose of improving CPT11 chemotherapy efficiency and alleviating toxicity.

Discovery of a series of 5-phenyl-2-furan derivatives containing 1,3-thiazole moiety as potent Escherichia coli β-glucuronidase inhibitors

Gut microbial β-glucuronidases have drawn much attention due to their role as a potential therapeutic target to alleviate some drugs or their metabolites-induced gastrointestinal toxicity. In this study, fifteen 5-phenyl-2-furan derivatives containing 1,3-thiazole moiety (1-15) were synthesized and evaluated for their inhibitory effects against Escherichia coli β-glucuronidase (EcGUS). Twelve of them showed satisfactory inhibition against EcGUS with IC₅₀ values ranging from 0.25 μM to 2.13 μM with compound 12 exhibited the best inhibition. Inhibition kinetics studies indicated that compound 12 (K_i = 0.14 ± 0.01 μM) was an uncompetitive inhibitor for EcGUS and molecular docking simulation further predicted the binding model and capability of compound 12 with EcGUS. A preliminary structure-inhibitory activity relationship study revealed that the heterocyclic backbone and bromine substitution of benzene may be essential for inhibition against EcGUS. The compounds have the potential to be applied in drug-induced gastrointestinal toxicity and the findings would help researchers to design and develop more effective 5-phenyl-2-furan type EcGUS inhibitors.

The Role of Gut Microbial β-Glucuronidase in Estrogen Reactivation and Breast Cancer

Over the past decade, the gut microbiota has received considerable attention for its interactions with the host. Microbial β-glucuronidase generated by this community has hence aroused concern for its biotransformation activity to a wide range of exogenous (foreign) and endogenous compounds. Lately, the role of gut microbial β-glucuronidase in the pathogenesis of breast cancer has been proposed for its estrogen reactivation activity. This is plausible considering that estrogen glucuronides are the primary products of estrogens' hepatic phase II metabolism and are subject to β-glucuronidase-catalyzed hydrolysis in the gut via bile excretion. However, research in this field is still at its very preliminary stage. This review outlines the biology of microbial β-glucuronidase in the gastrointestinal tract and elaborates on the clues to the existence of microbial β-glucuronidase-estrogen metabolism-breast cancer axis. The research gaps in this field will be discussed and possible strategies to address these challenges are suggested.

Human gut bacterial β-glucuronidase inhibition: An emerging approach to manage medication therapy

Bacterial β-glucuronidase enzymes (BGUSs) are at the interface of host-microbial metabolic symbiosis, playing an important role in health and disease as well as medication outcomes (efficacy or toxicity) by deconjugating a large number of endogenous and exogenous glucuronides. In recent years, BGUSs inhibition has emerged as a new approach to manage diseases and medication therapy and attracted an increasing research interest. However, a growing body of evidence underlines great genetic diversity, functional promiscuity and varied inhibition propensity of BGUSs, which have posed big challenges to identifying BGUSs involved in a specific pathophysiological or pharmacological process and developing effective inhibition. In this article, we offered a general introduction of the function, in particular the physiological, pathological and pharmacological roles, of BGUSs and their taxonomic distribution in human gut microbiota, highlighting the structural features (active sites and adjacent loop structures) that affecting the protein-substrate (inhibitor) interactions. Recent advances in BGUSs-mediated deconjugation of drugs and carcinogens and the discovery and applications of BGUS inhibitors in management of medication therapy, typically, irinotecan-induced diarrhea and non-steroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy, were also reviewed. At the end, we discussed the perspectives and the challenges of tailoring BGUS inhibition towards precision medicine.

Hypoxylonoids A-G: Isopimarane diterpene glycosides from Xylaria hypoxylon

Seven undescribed isopimarane diterpene glycosides hypoxylonoids A-G, along with five known analogues were obtained from the fungus Xylaria hypoxylon. The structures and absolute configurations of hypoxylonoids A-G were confirmed by extensive spectroscopic and single-crystal X-ray diffraction analyses. Among these compounds, the γ-lactone moiety formed between C-19 and C-6 of hypoxylonoid A; the 1,2-methyl shift of Me-18 of hypoxylonoids B and E; and the decarboxylation of C-19 of hypoxylonoid E, make them outstanding from the isopimarane family. Single crystal X-ray diffraction analyses of hypoxylonoids A, C, F, and 15-hydroxy-16-α-D-mannopyranosyloxyisopimar-7-en-19-oic acid was performed to determine their absolute structural configuration.

The Effects of Morinda citrifolia (Noni) on the Cellular Viability and Osteogenesis of Stem Cell Spheroids

Background and objectives: Morinda citrifolia (Noni) has been widely used in herbal remedies to treat and prevent various kinds of diseases. We conducted this study to evaluate the effects of Noni extract on the maintenance of morphology, the improvement of cellular viability, and the enhancement of osteogenesis of stem cell spheroids. Materials and Methods: We cultured stem cell spheroids made with gingiva-derived stem cells in the presence of Noni extract at concentrations of 10, 100 and 200 ng/mL. We performed analysis of the cell morphology and changes in the cellular viability. We conducted alkaline phosphatase activity assays using a kit, and mineralization assays using an anthraquinone dye to evaluate the osteogenesis of stem cell spheroids with the addition of Noni extract. Results: The applied cells formed spheroids well, and the addition of Noni at 10, 100 and 200 ng/mL concentrations did not produce significant morphological changes. The quantitative values for cellular viability on Day 3 showed that the absorbance values at 450 nm were 0.314 ± 0.013, 0.318 ± 0.008, 0.304 ± 0.000 and 0.300 ± 0.011 for Noni at 0, 10, 100 and 200 ng/mL concentrations, respectively. The results of alkaline phosphatase activity with absorbance values at 405 nm were 0.189 ± 0.019, 0.174 ± 0.023, 0.192 ± 0.014 and 0.210 ± 0.062 for Noni at 0, 10, 100 and 200 ng/mL concentrations, respectively, on Day 4. There were significantly higher values of Alizarin Red S staining for Noni in the 10, 100 and 200 ng/mL groups, with the highest value at 100 ng/mL when compared with the unloaded control on Day 14. Conclusions: Based on these findings, we concluded that Noni extract might be applied for the enhanced osteogenic differentiation of stem cell spheroids.