Isoprenoid flavonoids isolated from Sophora davidii and their activities induces apoptosis and autophagy in HT29 cells.

Four previously undescribed isoprenoid flavonoids (2-5) were isolated from Sophora davidii, along with five known analogues. The structures of the compounds were established through comprehensive analysis of spectroscopic data, including HRESIMS, 1D and 2D NMR, and absolute configurations determined by theoretical calculations, including ECD and NMR calculation. The cytotoxic effects of the isolated compounds on human HT29 colon cancer cells were evaluated using the MTT assay, compound 1 exhibited cytotoxicity against human HT29 colon cancer cells with an IC50 value of 8.39 ± 0.09 µM. Studies conducted with compound 1 in HT29 cells demonstrated that it may induce apoptosis and autophagy in HT29 by promoting the phosphorylation of P38 MAPK and inhibiting the phosphorylation of Erk MAPK.

Breaking barriers: How modified citrus pectin inhibits galectin-8.

Inhibition of galectin-3-mediated interactions by modified citrus pectin (MCP) could affect several rate-limiting steps in cancer metastasis, but the ability of MCP to antagonize galectin-8 function remains unknown. We hypothesized that MCP could bind to galectin-8 in addition to galectin-3. In this study, a combination of gradual ethanol precipitation and DEAE-Sepharose Fast Flow chromatography was used to isolate several fractions from MCP. The ability of these fractions to antagonize galectin-8 function was studied as well as the primary structure and initial structure-function relationship of the major active component MCP-30-3. The results showed that MCP-30-3 (168 kDa) was composed of Gal (13.8%), GalA (63.1%), GlcA (13.0%), and Glc (10.1%). MCP-30-3 could specifically bind to galectin-8, with an MIC value of 0.04 mg mL-1. After MCP-30-3 was hydrolyzed by ß-galactosidase or pectinase, its binding activity was significantly reduced. These results provide new insights into the interaction between MCP structure and galectin function, as well as the potential utility in the development of functional foods.

Diterpenoids from Torreya grandis and their cytotoxic activities.

Eight previously undescribed diterpenoids, along with eleven previously reported analogues, were obtained from the supercritical CO2 extracts of Torreya grandis aril. The structures of these compounds were elucidated based on HRESIMS, NMR, ECD, and single-crystal X-ray diffraction data. In the MTT assay, compound 18 exhibited significant inhibitory effects on two human colon cancer cell lines, HT-29 and HCT 116 cells, with IC50 values of 7.37 µM and 6.55 µM, respectively. It was found that compound 18 induced apoptosis and significantly inhibited the migration of HCT 116 colon cancer cells in a concentration-dependent manner.

Protective effect of solanesol in glucose-induced hepatocyte injury: Mechanistic insights on oxidative stress and mitochondrial preservation.

Solanesol is a tetra sesquiterpene enol with various biological activities. Modern medical studies have confirmed that solanesol has the function of lipid antioxidation and scavenges free radicals. This study aimed to investigate the protective effect of solanesol against oxidative damage induced by high glucose on human normal hepatocytes (L-02 cells) and its possible mechanism. The results showed that solanesol could effectively improve the decrease of cell viability induced by high glucose, decrease the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in the extracellular medium, increased the enzyme activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), balanced the level of reactive oxygen species (ROS) in cells, inhibited lipid peroxidation of all kinds of biological membranes, and restored mitochondrial membrane potential (MMP). In addition, Solanesol also inhibited the expression of Keap1, promoted the nuclear translocation of Nrf2 by hydrogen bonding with Nrf2, and activated the expression of downstream antioxidant factors NQO1 and HO-1. Altogether, these findings suggest that solanesol may be a potential protectant against diabetic liver injury.

Structural elucidation of lactone derivatives from Dendrobium pendulum.

Six lactone derivatives, including four α-pyrones derivatives (1-4), two α-furanone derivatives (5 and 6), were isolated from the Dendrobium pendulum. Structural elucidation of these undescribed lactone derivatives were accomplished on the basis of detailed nuclear magnetic resonance analysis, and the absolute configurations of compounds 1-4 were confirmed by electronic circular dichroism (ECD) techniques. The cytotoxic effects of isolated compounds on human breast cancer cell MDA-MB-231 were evaluated by the MTT assay.

Secondary Metabolites from Dendrobium nobile and Their Activities Induce Metabolites Apoptosis in OSC-19 Cells.

To identify potential drug candidates, secondary metabolites of Dendrobium nobile were performed. As a result, two previously undescribed phenanthrene derivatives with a spirolactone ring (1 and 2), along with four known compounds, N-trans-cinnamoyltyramine (3), N-trans-p-coumaroyltyramine (4), N-trans-feruloyltyramine (5), and moscatilin (6), were isolated from Dendrobium nobile. The structures of the undescribed compounds were elucidated using NMR spectroscopy, electronic circular dichroism (ECD) calculations, and extensive spectroscopic data analysis. The cytotoxic effects of compounds on human tongue squamous cells OSC-19 were determined using MTT at concentrations of 2.5 µM, 5 µM, 10 µM, and 20 µM. Compound 6 exhibited potent inhibitory activity against OSC-19 cells with an IC50 of 1.32 µM. Migration assays and western blot assays demonstrated that compound 6 effectively inhibited migration by down-regulating MMP2 and MMP9 at concentrations of 0.5 µM and 1 µM. To investigate its effect on apoptosis, we performed AO/PI staining, flow cytometry, and WB experiments. The results showed that increasing concentrations led to increased red fluorescence, decreased green fluorescence, increased apoptosis rate, decreased expression of bcl-2, caspase 3, caspase 9, and parp proteins, and increased bax expression. Furthermore, the phosphorylation of JNK and P38 was activated, suggesting that compound 6 may induce apoptosis via the MAPK pathway.

Complete 1 H and 13 C assignments of two new sesquiterpenoids from Dendrobium aduncum.

Two new sesquiterpenoids, dendroaduoid A (1) and dendroaduol (2), together with four known sesquiterpenoids were isolated from the stems of Dendrobium aduncum. Their structures were identified by HR-ESI-MS and NMR experiments, and the complete assignments of 1 H and 13 C NMR data for two new sesquiterpenoids were obtained by the aid of HSQC, HMBC, 1 H-1 H COSY, NOESY, and ECD techniques. The cytotoxic effects of the isolated compounds on four tumor cell lines (HCT-116, HepG2, A549, and SW1990) were evaluated using MTT assay. Otherwise, the inhibitory activity of these six sesquiterpenoids on glycosidase was also evaluated.

Dihydrophenanthrenes and phenanthrenes from Dendrobium terminale.

Two previously undescribed dihydrophenanthrene derivatives (1 and 2) were isolated along with twelve known analogues from the whole plant of Dendrobium terminale. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. The NMR data of known phenanthrene derivatives (7 and 9) were revised by 2D NMR. The isolated compounds were evaluated for cytotoxicity against three kinds of tumor cell lines (sw1990, HCT-116, and HepG2). Especially compounds 11 and 14 showed stronger antitumor effects, and the structure-activity relationship of these compounds was discussed.

Glucosyloxybenzyl 2-isobutylmalates and phenolic glycosides from the flowers of Bletilla striata.

Four previously undescribed compounds, including three glucosyloxybenzyl 2-isobutylmalates (1-3), one phenolic glycoside (4), along with ten known compounds were isolated from the flowers of Bletilla striata. The structures and absolute configurations of the undescribed compounds were elucidated on the basis of HR-ESIMS, NMR spectroscopy, optical rotation value, and acid hydrolysis experiment. Cytotoxicity of the isolated compounds against A549, HCT-116, and SW1990 cells and protective effects of t-BHP-induced L02 cytotoxic were assayed. The antioxidant activities of the isolated compounds were also evaluated.

Dendrobine-type alkaloids from Dendrobium nobile.

Six dendrobine-type alkaloids were isolated from the tubes of Dendrobium nobile by silica gel, Sephadex LH-20 gel column chromatography, and preparative HPLC. Compound 1 is a new alkaloid containing a pair of amide tautomers, whereas compound 2 is a new dendrobine-type alkaloid. By using spectroscopic techniques including 1 D and 2 D NMR, the structures of compounds 1‒6 were identified as N-methoxylcarbonyldendrobine (1), dendronboic acid (2), dendrobine (3), 6-hydroxyldendrobine (4), dendrobine N-oxide (5), and denrine (6). The cytotoxic effects of the isolated compounds on two human tumour cell lines (HCT-116 and SW1990) were evaluated using MTT assay.

Purification, chemical analysis and inhibitory effects on galectin-3 of enzymatic pH-modified citrus pectin.

Modified citrus pectin (MCP), a commercially available dietary supplement prepared from citrus pectin, contains several different polysaccharide domains, but its primary chemical structure and the binding epitopes that antagonize galectin-3 function remain unclear. In this study, five fractions were isolated from MCP after endo-polygalacturonase degradation (EMCP) and a combination of DEAE-cellulose and Sepharose CL-6B or Sephadex G-75 chromatography. Their primary structures, abilities to inhibit galectin-3-mediated hemagglutination, and antiproliferation activities on MCF-7 and A549 cell lines were studied. Results showed that EMCP-3p, one of the five fractions, was composed of Glc (89.8%), Gal (3.8%), Ara (3.1%), GalA (1.1%), Man (0.9%), and Rha (1.3%) with an average molecular weight of 88.4 KDa, which had the most substantial degree of galectin-3 inhibition with an MIC of 31.25 µg/mL, and it exhibited remarkable cytotoxicity against MCF-7 (36.7%) and A549 (57.4%) cell lines. These results provide new insight into the structure-function relationships of EMCP-derived polysaccharides.

Cardioprotective effects of Amentoflavone by suppression of apoptosis and inflammation on an in vitro and vivo model of myocardial ischemia-reperfusion injury.

Inflammation modulation is currently considered a promising therapeutic strategy to counteract the burden of cardiovascular disease. Amentoflavone (AME) is a natural biflavone with two apigenin molecules that, possess promising anti-inflammatory, anti-oxidative, and anti-cancer properties. In the present study, we aimed to investigate the effects of AME on myocardial ischemia-reperfusion injury in vivo and in vitro, and to elucidate the underlying mechanism. Our results showed that AME significantly reduced the levels of LDH, CK-MB, IL-6, IL-1ß, and TNF-α after hypoxia (H) 12 h/reoxygenation (R) 4 h treatment, and significantly increased the cell survival rate of H9c2 cardiomyocytes induced by H/R and inhibited their apoptosis rate. AME (25, 50, 100 mg·kg-1·d-1, i.g.) or a positive control drug diltiazem (DIZ) (16 mg·kg-1·d-1, i.g.) was used as pretreatment for 7 days; the myocardial ischemia-reperfusion(I/R) model was established. TTC staining results showed that the infarct volume was significantly reduced after AME and DIZ treatment. Oral administration of AME dose-dependently ameliorated I/R injury-induced increase in pro-inflammatory factors (IL-6, IL-1ß, and TNF-α) and levels of LDH and CK-MB. Results of TUNEL and HE staining showed that the I/R model had more induced apoptosis, but could be effectively reduced by pretreatment with AME. After surgery, the heart of the rat was examined via western blotting to detect inflammation-related proteins. Compared with the sham group, the p-AKT in the I/R group was significantly reduced and the content of p-NF-κBp65 was significantly increased. However, these changes could be reversed by AME treatment. DIZ treatment exerted similar beneficial effects in I/R rats as the high dose of AME did. This study highlights the excellent therapeutic potential of AME for managing myocardial ischemia-reperfusion injury.

A new triterpenoids from Nothotsuga longibracteata.

A new lanostane triterpenoid (1) and two known (2, 3) analogues were isolated from Nothotsuga longibracteata. Their chemical structures were identified by spectral data including HR-ESI-MS, 1 D, and 2 D NMR. These lanostane triterpenoids showed no cytotoxic activities against three human tumour cell lines (A172, SHSY5Y, and Hela), but exhibited the activity of promoting the gastrointestinal motility of zebrafish treated with Nile red.

Analysis of the water-soluble polysaccharides from Camellia japonica pollen and their inhibitory effects on galectin-3 function.

Pollen has been defined as dietary supplement used to supplement the diet in many countries, but the primary structure and activity of Camellia japonica pollen polysaccharide remain unclear. In this study, the water-soluble polysaccharide extracted from Camellia japonica pollen (WCPP) was fractionated into one neutral fraction (WCPP-N) and two acidic fractions (WCPP-A1 and WCPP-A2) by DEAE-cellulose column, and WCPP-A2 was further fractionated into two homogeneous sub-fractions (WCPP-A2a and WCPP-A2b) by Sepharose CL-6B column. Monosaccharide composition results showed that WCPP-N might mainly contain starch-like glucan as well as some arabinogalactan, while WCPP-A1, WCPP-A2 and its sub-fractions might mainly composed of rhamnogalacturonan I (RG-I) pectic polysaccharide domain backbone with some different types of side chains, including arabinan, galactan, and/or arabinogalactan. The primary structure analysis of WCPP-A2a by NMR spectra analysis suggested that WCPP-A2a was an RG-I-like pectic polysaccharide, branched at the O-4 of Rha residues in the backbone, with α-(1 â†’ 3,5)-L-arabinan as well as type-II arabinogalactan side chain to which were attached. The results of galectin-3-mediated hemagglutination assay indicated that WCPP-A2a exhibited the strongest inhibitory effect on galectin-3 with MIC value around 0.27 µg/mL. These results suggested the potential use of Camellia japonica pollen polysaccharide as a galectin3 inhibitor in functional foods.

Identification of Specific Joint-Inflammatogenic Cell-Free DNA Molecules From Synovial Fluids of Patients With Rheumatoid Arthritis.

Elevated cell-free DNA (cfDNA) levels in the plasma and synovial fluid of rheumatoid arthritis (RA) patients are proposed to be pathologically relevant. However, direct evidence to support this perception is lacking, and molecular feature of the cfDNA molecules with assumed pathological function is not well characterized. Here, we confirm remarkably increased levels of total synovial fluid and plasma cfDNAs in a large cohort of patients with rheumatoid arthritis compared to the counterparts in osteoarthritis, and demonstrate the potent inflammatogenic effects of RA synovial fluid cfDNA on both human monocyte cell line and primary cells related to RA. Massively parallel sequencing identifies distinct molecular pattern of cfDNA in RA, as characterized by enriching CpG-motif containing sequences. Importantly, these identified CpG-motif-rich sequences are hypomethylated in RA patients and induce severe inflammatory responses both in vitro and in vivo. Our data demonstrate the pathological role of global and specific cfDNA molecules in RA, thereby identifying novel therapeutic target candidate and potential biomarker for RA.

Amentoflavone suppresses amyloid ß1-42 neurotoxicity in Alzheimer's disease through the inhibition of pyroptosis.

BACKGROUND: The accumulation of Amyloid ß (Aß) plays key roles in Alzheimer's disease (AD) by inducing intracellular reactive oxygen species (ROS) and neuronal cell death. In this study, we aimed to identify the neuroprotective mechanisms of amentoflavone (AF) in Aß-induce neuronal cell injury. MATERIALS AND METHODS: The animal model was established by injecting Aß1-42 into the bilateral hippocampus. The effect of AF on Aß1-42-induced neurological dysfunction was examined using the Y-maze and radical maze tests. The hippocampal neuron viability was examined using Nissl staining and TUNEL assay. On the other hand, in vitro studies were conducted using SH-SY5Y cells. The expression level of marker proteins was measured using western blot. The activity of caspase-1 and the levels of pro-inflammatory cytokines were determined using ELISA assay. AMPKα knock down was carried out by transfecting SH-SY5Y cells with siRNA against AMPK transcript. RESULTS: Neurological tests showed that AF significantly attenuated Aß1-42-induced neurological dysfunction. AF suppressed Aß1-42-induced pyroptosis in the hippocampal region of the rat model, which was associated with the modulation of AMPK/GSK3ß signaling. Similar results were obtained in vitro in SH-SY5Y cells exposed to Aß1-42, showing that the neuroprotective activity of AF is mediated by suppressing pyroptosis through AMPK/GSK3ß signaling. CONCLUSION: AF inhibits Aß1-42-induced neurotoxicity in animal and cellular models through AMPK/GSK3ß-mediated pyroptosis suppression. Our results highlight AF as a clinical compound for the prevention and treatment of AD.

Ionic Liquid-Microwave-Based Extraction of Biflavonoids from Selaginella sinensis.

Selaginella sinensis (Desv.) Spring has been used for many years as traditional Chinese medicine (TCM) for many years. Recently, ionic liquids (ILs) have attracted great attentions in extraction and separation technology of TCM as a new green solvent. In this paper, microwave assisted extraction-IL (MAE-IL) that extracted amentoflavone (AME) and hinokiflavone (HIN) from Selaginella sinensis was reported for the first time. The contents of two biflavonoids were simultaneously determined by a high performance liquid chromatography (HPLC) method. After different ionic liquids were compared, it was found [C6mim]BF4 had a high selectivity and efficiency. Moreover, the important extraction conditions, including solid-liquid ratio, IL concentration, extraction time, microwave power and radiation temperature, were also investigated and optimized by response surface methodology (RSM) using AME and HIN yields as index. The results showed that the extraction yields of AME and HIN from S. sinensis were 1.96 mg/g and 0.79 mg/g, respectively, under the optimal process parameters (0.55 mmol/L, 300 W, 40 min, 1:11 g/mL and 48 °C). Compared with the conventional extraction methods, MAE-IL could not only achieve higher yield in shorter time, but also could reduce the consumption of solvent. This effective, rapid and green MAE-IL method was suitable for the extraction of AME and HIN.

Regulatory Mechanisms of the Wnt/ß-Catenin Pathway in Diabetic Cutaneous Ulcers.

Skin ulcers are a serious complication of diabetes. Diabetic patients suffer from vascular lesions and complications such as peripheral neuritis, peripheral vascular lesions, and collagen abnormalities, which result in skin wounds that are refractory and often develop into chronic ulcers. The healing of skin ulcers requires an inflammatory reaction, wound proliferation, remodeling regulation, and control of stem cells. Studies investigating diabetic cutaneous ulcers have focused on cellular and molecular levels. Diabetes can cause nerve and blood vessel damage, and persistent high blood sugar levels can cause systemic multisite nerve damage based on peripheral neuropathy. The long-term hyperglycemia state enables the polyol glucose metabolism pathway to be activated, increasing the accumulation of toxic substances in the vascular injured nerve tissue cells. Sustained hyperglycemia leads to dysfunction of epithelial cells, leading to a decrease in pro-angiogenic signaling and nitric oxide production. In addition, due to impaired leukocyte function in hyperglycemia, immune function is impaired and the immune response at relevant sites is insufficient, making diabetic foot more difficult to heal. The Wnt/ß-catenin pathway is a highly conserved signal transduction pathway involved in a variety of biological processes, such as cell proliferation, apoptosis, and differentiation. It is considered an important pathway involved in the healing of skin wounds. This article summarizes the mechanism of action of the Wnt/ß-catenin pathway involved in the inflammatory responses to diabetic ulcers, wound proliferation, wound remodeling, and stem cells. The interactions between the Wnt signal pathway and other metabolic pathways are also discussed.

Uniform Core-Shell Nanoparticles with Thiolated Hyaluronic Acid Coating to Enhance Oral Delivery of Insulin.

Oral delivery of protein drugs is an attractive route of administration due to its convenience for repeated dosing and good patient compliance. However, currently oral protein therapeutics show very low bioavailability mainly due to the existence of hostile gastrointestinal (GI) environments, including mucus layers and intestinal epithelial barriers. Herein, using insulin as a model protein therapeutic, the core-shell nanoparticles with thiolated hyaluronic acid (HA-SH) coating (NPHA-SH ) are produced utilizing a two-step flash nanocomplexation process to enhance oral delivery efficiency of insulin. A positively charged nanoparticle core is first generated by electrostatic complexation between insulin and N-(2-hydroxypropyl)-3-trimethyl ammonium chloride modified chitosan (HTCC), followed by surface coating with HA-SH. The optimized NPHA-SH shows an average size of 100 nm with high encapsulation efficiency (91.1%) and loading capacity (38%). In vitro and ex vivo results confirm that NPHA-SH shows high mucus-penetration ability, improved intestinal retention and transepithelial transport property due to its thiolated surface and the ability of HA-SH coating to dissociate from the nanoparticle surface when across the mucosal layer. Oral administration of NPHA-SH to Type 1 diabetic rats yields high efficacy and an average relative bioavailability of 11.3%. These results demonstrate that the HA-SH coated core-shell nanoparticles are a promising oral delivery vehicle for protein therapeutics.

Insulin/Snail1 axis ameliorates fatty liver disease by epigenetically suppressing lipogenesis.

Insulin stimulates lipogenesis but insulin resistance is also associated with increased hepatic lipogenesis in obesity. However, the underlying mechanism remains poorly characterized. Here, we show a noncanonical insulin-Snail1 pathway that suppresses lipogenesis. Insulin robustly upregulates zinc-finger protein Snail1 in a PI 3-kinase-dependent manner. In obesity, the hepatic insulin-Snail1 cascade is impaired due to insulin resistance. Hepatocyte-specific deletion of Snail1 enhances insulin-stimulated lipogenesis in hepatocytes, exacerbates dietary NAFLD in mice, and attenuates NAFLD-associated insulin resistance. Liver-specific overexpression of Snail1 has the opposite effect. Mechanistically, Snail1 binds to the fatty acid synthase promoter and recruits HDAC1/2 to induce deacetylation of H3K9 and H3K27, thereby repressing fatty acid synthase promoter activity. Our data suggest that insulin pathways bifurcate into canonical (lipogenic) and noncanonical (anti-lipogenesis by Snail1) two arms. The noncanonical arm counterbalances the canonical arm through Snail1-elicited epigenetic suppression of lipogenic genes. Impairment in the insulin-Snail1 arm may contribute to NAFLD in obesity.