Oenothein B from Eugenia uniflora leaves exerts pro-angiogenic effects by increasing VEGF and TNF-α levels.

Oenothein B (OeB), a dimeric ellagitannin with a macrocyclic structure, is reported to have beneficial effects, including antioxidant, antitumor, antiviral, and antimutagenic effects, on human health. Despite the remarkable properties of OeB, its role in neovascularization process has not yet been evaluated. Thus, this study aimed to evaluate the angiogenic activity of OeB using a chorioallantoic membrane (CAM) assay at different concentrations (6.25, 12.5, and 25 µg/µL), employing digital imaging and histological analysis. Furthermore, to elucidate the mechanisms by which OeB influences angiogenesis, we assessed the levels of vascular endothelial growth factor (VEGF) and tumor necrosis factor-alpha (TNF-α) in CAM using immunohistochemical analysis. All concentrations of OeB significantly increased (p < 0.05) the percentage of vascularization as well as the levels of all the angiogenesis-associated parameters evaluated, indicating the pronounced pro-angiogenic activity of OeB. Our results showed that inflammation was one of the most relevant phenomena observed in CAM histology along with angiogenesis. In addition, a significant increase in VEGF and TNF-α levels was observed in all the CAMs compared to the negative control (p < 0.05). We suggest that OeB may induce the presence of inflammatory cells in CAM, leading to increased VEGF and TNF-α levels that result in the induction of angiogenesis. Therefore, OeB presents a favorable profile that could be further explored for the development of drugs for pro-angiogenic and tissue repair therapies.

Uncovering the colorectal cancer immunotherapeutic potential: Evening primrose (Oenothera biennis) root extract and its active compound oenothein B targeting the PD-1/PD-L1 blockade.

BACKGROUND: The emergence of immune checkpoint inhibitors, a novel class of immunotherapy drugs, represents a major breakthrough in cancer immunotherapy, substantially improving patient survival post-treatment. Blocking programmed death-ligand 1 (PD-L1) and programmed death protein-1 (PD-1) has demonstrated promising clinical results in various human cancer types. The US FDA has recently permitted only monoclonal antibody (mAb)-based PD-L1 or PD-1 blockers. Although these antibodies exhibit high antitumor efficacy, their size- and affinity-induced side effects limit their applicability. PURPOSE: As small-molecule-based PD-1/PD-L1 blockers capable of reducing the side effects of antibody therapies are needed, this study focuses on exploring natural ingredient-based small molecules that can target hPD-L1/PD-1 using herbal medicines and their components. METHODS: The antitumor potential of evening primrose (Oenothera biennis) root extract (EPRE), a globally utilized traditional herbal medicine, folk remedy, and functional food, was explored. A coculture system was established using human PD-L1-expressed murine MC38 cells (hPD-L1-MC38s) and CD8+ tumor-infiltrating T lymphocytes (CD8+ TILs) expressing humanized PD-1. The in vivo experiments utilized a colorectal cancer (CRC) C57BL/6 J mouse model bearing MC38 cells expressing humanized PD-L1 and PD-1 proteins. RESULTS: EPRE and its active compound oenothein B effectively hindered the molecular interaction between hPD-L1 and hPD-1. EPRE stimulated tumor-specific T lymphocytes of a hPD-L1/PD-1 CRC mice. This action resulted in the elevated infiltration of cytotoxic CD8+T lymphocytes and subsequent tumor growth reduction. Moreover, the combined therapy of oenothein B, a PD-1/PD-L1 blocker, and FOLFOX (5-fluorouracil plus oxaliplatin) cooperatively suppressed hPD-L1-MC38s growth in the ex vivo model through activated CD8+ TIL antitumor immune response. Oenothein B exhibited a high binding affinity for hPD-L1 and hPD-1. We believe that this study is the first to uncover the inhibitory effects of EPRE and its component, oenothein B, on PD-1/PD-L1 interactions. CONCLUSION: This study identified a promising small-molecule candidate from natural products that blocks the hPD-L1/PD-1 signaling pathway. These findings emphasize the potential of EPRE and oenothein B as effective anticancer drugs.

Turkish Plants, Including Quercetin and Oenothein B, Inhibit the HIV-1 Release and Accelerate Cell Apoptosis.

The introduction of combined anti-retroviral therapy (cART) in 1996, along with a continual breakthrough in anti-human immunodeficiency virus-1 (HIV-1) drugs, has improved the life expectancies of HIV-1-infected individuals. However, the incidence of drug-resistant viruses between individuals undergoing cART and treatment-naïve individuals is a common challenge. Therefore, there is a requirement to explore potential drug targets by considering various stages of the viral life cycle. For instance, the late stage, or viral release stage, remains uninvestigated extensively in antiviral drug discovery. In this study, we prepared a natural plant library and selected candidate plant extracts that inhibited HIV-1 release based on our laboratory-established screening system. The plant extracts from Epilobium hirsutum L. and Chamerion angustifolium (L.) Holub, belonging to the family Onagraceae, decreased HIV-1 release and accelerated the apoptosis in HIV-1-infected T cells but not uninfected T cells. A flavonol glycoside quercetin with oenothein B in Onagraceae reduced HIV-1 release in HIV-1-infected T cells. Moreover, extracts from Chamerion angustifolium (L.) Holub and Senna alexandrina Mill. inhibited the infectivity of progeny viruses. Together, these results suggest that C. angustifolium (L.) Holub contains quercetin with oenothein B that synergistically blocks viral replication and kills infected cells via an apoptotic pathway. Consequently, the plant extracts from the plant library of Turkey might be suitable candidates for developing novel anti-retroviral drugs that target the late phase of the HIV-1 life cycle.

Chemopreventive effect and induction of DNA repair by oenothein B ellagitannin isolated from leaves of Eugenia uniflora in Swiss Webster treated mice.

Oenothein B (OeB) is a dimeric ellagitannin with potent antioxidative, antitumor, immunomodulatory, and anti-inflammatory properties. Despite the promising activities of OeB, studies examining the genotoxic or protective effects of this ellagitannin on DNA are scarce. Therefore, to further comprehensively elucidate the chemopreventive profile of OeB, the aim of this study was to evaluate the mutagenic and antimutagenic actions of OeB using Salmonella typhimurium strains with the Ames test. The micronucleus (MN) test and comet assay were used to assess the anticytotoxic and antigenotoxic effects of OeB on mouse bone marrow cells following differing treatments (pre-, co-, and post-treatment) in response to cyclophosphamide (CPA)-induced DNA damage. In addition, histopathological analyses were performed to assess liver and kidney tissues of Swiss Webster treated mice. Our results did not detect mutagenic or antimutagenic activity attributed to OeB at any concentration in the Ames test. Regarding the MN test, data showed that this ellagitannin exerted antigenotoxic and anticytotoxic effects against CPA-induced DNA damage under all treatment conditions. However, no anticytotoxic action was observed in MN test after pre-treatment with the highest doses of OeB. In addition, OeB demonstrated antigenotoxic effects in the comet assay for all treatments. Histopathological analyses indicated that OeB attenuated the toxic effects of CPA in mouse liver and kidneys. These findings suggest that OeB exerted a chemoprotective effect following pre- and co-treatments and a DNA repair action in post-treatment experiments. Our findings indicate that OeB protects DNA against CPA-induced damaging agents and induces post-damage DNA repair.

[Oenothein B inhibits proliferation and migration of breast cancer cells by regulating P53].

The effects of oenothein B(OEB) on the proliferation, apoptosis, invasion, and migration of breast cancer MCF-7 and MDA-MB-231 cells were investigated by cell culture in vitro, network pharmacology, and molecular docking. In vitro cell experiments revealed that OEB inhibited the proliferation and colony formation ability, and promoted the apoptosis and formation of apoptotic bodies in breast cancer cells, as well as inhibited the invasion and migration of breast cancer cells. The targets of OEB were obtained using SwissTargetPrediction database and breast cancer targets were obtained from GeneCards. The targets of OEB and breast cancer were entered separately in Venny 2.1 software to obtain the Venn diagram of common targets of OEB and breast cancer. The common targets of OEB and breast cancer were input into STRING database to construct a protein-protein interaction(PPI) network, which was entered into Cytoscape 3.7.2 software for network topology analysis. Key targets were screened according to protein association strength, and analyzed for KEGG pathway enrichment. Molecular docking of OEB to key targets using AutoDock software revealed that OEB stably bound to the active pocket of P53, while OEB promoted the expression of P53 protein. MCF-7 and MDA-MB-231 cell viability and migration ability increased after silencing P53, and this change was reversed after treatment with OEB. Therefore, this study showed that OEB inhibited the proliferation, migration, and invasion of breast cancer MCF-7 and MDA-MB-231 cells, and promoted the apoptosis of breast cancer MCF-7 and MDA-MB-231 cells, which may be related to the targeted regulation of P53.

In vitro cytotoxic activity of Cuphea ingrata Cham. & Schltdl. extracts related to the oenothein B content.

Cuphea ingrata is a traditional medicinal plant species of the Lythraceae family. This work reports on the cytotoxic activity of the methanolic extract from the aerial parts of C. ingrata and the n-butanol and ethyl acetate fractions against human skin and prostate cancer cells. The selectivity of action was tested in normal skin keratinocytes HaCaT and prostate epithelial cells PNT2. The ethyl acetate fraction showed the highest activity in all three human skin cancer cell lines: A375, HTB-140, WM793, with IC50 = 15.90; 3.40; 18.75 µg/mL, respectively. To obtain comparative information on the chemical composition, a quantitative analysis of oenothein B was performed using the UHPLC-PDA method. An analysis of its cytotoxic activity was also carried out.

Oenothein B inhibits proliferation and migration of breast cancer cells by regulating P53 / 中国中药杂志

The effects of oenothein B(OEB) on the proliferation, apoptosis, invasion, and migration of breast cancer MCF-7 and MDA-MB-231 cells were investigated by cell culture in vitro, network pharmacology, and molecular docking. In vitro cell experiments revealed that OEB inhibited the proliferation and colony formation ability, and promoted the apoptosis and formation of apoptotic bodies in breast cancer cells, as well as inhibited the invasion and migration of breast cancer cells. The targets of OEB were obtained using SwissTargetPrediction database and breast cancer targets were obtained from GeneCards. The targets of OEB and breast cancer were entered separately in Venny 2.1 software to obtain the Venn diagram of common targets of OEB and breast cancer. The common targets of OEB and breast cancer were input into STRING database to construct a protein-protein interaction(PPI) network, which was entered into Cytoscape 3.7.2 software for network topology analysis. Key targets were screened according to protein association strength, and analyzed for KEGG pathway enrichment. Molecular docking of OEB to key targets using AutoDock software revealed that OEB stably bound to the active pocket of P53, while OEB promoted the expression of P53 protein. MCF-7 and MDA-MB-231 cell viability and migration ability increased after silencing P53, and this change was reversed after treatment with OEB. Therefore, this study showed that OEB inhibited the proliferation, migration, and invasion of breast cancer MCF-7 and MDA-MB-231 cells, and promoted the apoptosis of breast cancer MCF-7 and MDA-MB-231 cells, which may be related to the targeted regulation of P53.

Oenothein B ameliorates hepatic injury in alcoholic liver disease mice by improving oxidative stress and inflammation and modulating the gut microbiota.

Introduction: Alcoholic liver disease (ALD) is a global health problem for which there is no current food and drug administration (FDA)-approved therapy. Oenothein B (OEB) is a macrocyclic dimer ellagic tannin that possesses abundant biological activities including antioxidant, anti-inflammation, antitumor, immunomodulatory, and antimicrobial properties. Materials and methods: In this study, the hepatoprotective effect of OEB against ALD was investigated in vivo and in vitro. Results: We found that OEB treatment dramatically reduced alcohol-induced hepatic injury, as evidenced by decreased levels of aminotransferases and inflammatory biomarkers and increased antioxidant capacity in OEB-treated groups. Discussion: OEB treatment alleviated oxidative stress by upregulating the Keap1/Nrf2 signaling pathway and inhibited inflammation by downregulating the TLR4/NF-κB signaling pathway. Additionally, OEB treatment positively improved alcohol-induced intestinal microbial dysbiosis by modulating the structure and composition of gut microbiota. Interestingly, we observed the increasement of short-chain fatty acid (SCFA) producers (Muribaculaceae) and the decreasement of Gram-negative bacteria (Akkermansia) in the OEB treatment groups, which may contribute to the inhibition of hepatic oxidative stress and inflammation via the gut-liver axis. In summary, our findings indicate that OEB is a promising therapeutic strategy for preventing and treating ALD.

Epilobium Species: From Optimization of the Extraction Process to Evaluation of Biological Properties.

Epilobium species are used in Romanian folk medicine as tinctures, tea, or tablets for ameliorating the symptoms of benign prostate hyperplasia (BPH), but scientific-based evidence is scarce for this species or other endemic plants of the same genus. Therefore, the aims of this research were to evaluate the phytochemical profile of five endemic Epilobium species (E. hirsutum L., E. parviflorum Schreb., E. palustre L. E. dodonaei Vill., and E. angustifolium L.) and to assess their in vitro biological activity. For enhanced recovery of polyphenols, a D-optimal experimental plan was developed using Modde software and the optimal working conditions were ultra-turrax-assisted extraction, for 8 min, with 30% ethanol in water. The optimized extracts were obtained from various plant parts and were further characterized by LC-MS analysis, with the major compound being oenothein B. All extracts demonstrated good antioxidant activity, evaluated by DPPH and TEAC assays. The most prominent antimicrobial potency of optimized extracts was displayed against Bacillus cereus, while against Gram-(+) bacteria, a moderate efficacy was observed. Furthermore, anti-cancer, anti-inflammatory, and antioxidant potential were assessed on normal fibroblasts and prostate carcinoma cell lines. From the evaluated optimized extracts, E. angustifolium aerial parts had the highest selectivity toward killing cancerous cells, followed by E. hirsutum aerial parts extract. For the antioxidant effect, E. hirsutum leaves and E. hirstum aerial parts extracts displayed the highest potency, decreasing ROS at the level observed for the positive control. The highest anti-inflammatory potential, based on the IL-6 and IL-8 levels, was displayed by E. dodonaei aerial parts and E. angustifolium leaves extracts. In conclusion, all five endemic species of Epilobium harvested from Romanian flora possess a diverse phytochemical composition, which supports complex biological activities.

Shedding Light into the Connection between Chemical Components and Biological Effects of Extracts from Epilobium hirsutum: Is It a Potent Source of Bioactive Agents from Natural Treasure?

Epilobium hirsutum is extensively used as a traditional remedy in folk medicine, especially against prostate inflammation. Therefore, we evaluated the chemical profiles and biopharmaceutical potentials of different extracts of E. hirsutum aerial parts and roots. Metabolomic, antioxidant, and enzyme inhibitory profiles were investigated. Human prostate cancer PC3 cells were exposed to the extracts to evaluate antiproliferative effects. Gene expression and bioinformatics analyses were performed to investigate anti-inflammatory mechanisms. Oenothein B and myricetin were prominent compounds in the extracts. In scavenging/reducing assays, the methanol, infusion, and methanol/water extracts exhibited similar activities. We also observed the reduction of PC3 viability occurring following exposure to methanol and methanol/water extracts. According to bioinformatics analysis, myricetin was predicted to interact with COX-2 and TNFα. The interaction between TNFα and oxo-dihydroxy-octadecenoic acid was predicted as well. Intriguingly, the gene expression of COX-2 and TNFα was reduced in PC3 cells after exposure to methanol and methanol/water extracts. These effects were paralleled by the decreased gene expression of IL-8 and NFkB and the inhibition of PGE2 release. Therefore, the present findings suggest the potential use of E. hirsutum for the management of the burden of inflammation and oxidative stress occurring in lower urinary tract diseases, including prostatitis.

Oenothein B, a Bioactive Ellagitannin, Activates the Extracellular Signal-Regulated Kinase 2 Signaling Pathway in the Mouse Brain.

(1) Background: Oenothein B, a cyclic dimeric ellagitannin present in various medicinal plants, has been reported to exert diverse effects that are beneficial for the treatment and prevention of diseases, including cancer and infections. We recently showed that oenothein B also functions in the brain because its oral administration to systemic inflammatory model mice reduced inflammatory responses in the brain and suppressed abnormal behavior. (2) Results: The present in vivo results demonstrated that oenothein B activated extracellular signal-regulated kinase 2 and cAMP response element-binding protein in the brain, both of which play important roles in synaptic transmission and learning/memory in the central nervous system (CNS). (3) Conclusions: These results suggest that oenothein B exerts neuroprotective effects on the CNS by not only its anti-inflammatory activity but also by enhancing neuronal signaling pathways.

Epilobium angustifolium L. extract with high content in oenothein B on benign prostatic hyperplasia: A monocentric, randomized, double-blind, placebo-controlled clinical trial.

Benign prostatic hyperplasia (BPH) is a common condition in adult men. Especially in Europe, increasing attention has been focused on E. angustifolium extracts (EAEs), which are widely used for their positive effects on the symptoms of BPH, although human clinical trials are limited. The aim of this monocentric, randomized, double-blind, placebo-controlled clinical trial is to evaluate if a daily intake of hard, gastric-resistant capsules containing a chemically characterized EAE (500 mg) for 6 months may allow a significant improvement in symptoms in subjects with BPH. This study was conducted in 128 adult men, randomly assigned to receive either EAE food supplement (N = 70) or placebo (N = 58), who underwent four visits (baseline = t0, after 15 days = t1, after 2 months = t2 and after 6 months = t3) in an outpatient setting to evaluate post-void residual (PVR) and prostate volume (PV) by means of prostate ultrasound, prostate-specific antigen (PSA) and neutrofile/lymphocyte ratio (N/L), nocturia before the clinical visits and International Prostate Specific Score (IPSS) registered by the physicians. EAE food supplement induced a significant decrease in the PVR and consequently nocturia improving the quality of life as suggested by the decrease of IPSS. No subjects reported adverse effects related to oral intake of EAE food supplement. Moreover, EAE food supplement did not show hepatic or renal toxicity. In conclusion, EAE food supplements can be used in subjects with BPH, to improve their quality of life and general renal function.

Oenothein B in Eucalyptus Leaf Extract Suppresses Fructose Absorption in Caco-2 Cells.

Inhibition of fructose absorption may suppress adiposity and adiposity-related diseases caused by fructose ingestion. Eucalyptus leaf extract (ELE) inhibits intestinal fructose absorption (but not glucose absorption); however, its active compound has not yet been identified. Therefore, we evaluated the inhibitory activity of ELE obtained from Eucalyptus globulus using an intestinal fructose permeation assay with the human intestinal epithelial cell line Caco-2. The luminal sides of a cell monolayer model cultured on membrane filters were exposed to fructose with or without the ELE. Cellular fructose permeation was evaluated by measuring the fructose concentration in the medium on the basolateral side. ELE inhibited 65% of fructose absorption at a final concentration of 1 mg/mL. Oenothein B isolated from the ELE strongly inhibited fructose absorption; the inhibition rate was 63% at a final concentration of 5 µg/mL. Oenothein B did not affect glucose absorption. In contrast, the other major constituents (i.e., gallic acid and ellagic acid) showed little fructose-inhibitory activity. To our knowledge, this is the first report that oenothein B in ELE strongly inhibits fructose absorption in vitro. ELE containing oenothein B can prevent and ameliorate obesity and other diseases caused by dietary fructose consumption.

Metabolic profiling, in vitro bioaccessibility and in vivo bioavailability of a commercial bioactive Epilobium angustifolium L. extract.

The global diffusion of benign prostatic hyperplasia (BPH) demands the search for safe and effective treatment alternatives to the drugs commonly used, which exert both side and adverse effects. Among plant-based products, the extracts of Epilobium angustifolium L. (EAEs) could improve BPH symptoms thanks to the presence of ellagitannins and their anti-inflammatory metabolites, urolithins. This study focused its attention on a commercial EAE, standardized to contain ≥ 15 % oenothein B, to determine a) the metabolic profile and the chemical degradation induced by digestion, b) in vivo bioavailability after acute and prolonged treatments of CD1 mice, and c) in vitro antioxidant activity. Utilizing RP-HPLC-PDA-ESI-MSn analysis, 20 different compounds were identified. Polyphenols suffered from degradation after both orogastric and duodenal digestion processes, suggesting that gastro-resistant coating agents are required to preserve the bioactive components occurring in the EAE phytocomplex from orogastric digestion. In vivo data underlined the presence of urolithins only after the prolonged treatment, confirming that the gut fermentation process requires at least 24 h to produce urolithins. Finally, an increase of Superoxide Dismutase-1 (SOD-1), which represents one of the fundamental endogenous antioxidant defenses, was determined in an EAE pretreated LNCap cell model system, confirming EAE antioxidant activity.

Effect of Different Durations of Solid-Phase Fermentation for Fireweed (Chamerion angustifolium (L.) Holub) Leaves on the Content of Polyphenols and Antioxidant Activity In Vitro.

Fireweed has recently been recognized as a plant with high antioxidant potential and phenolic content. Its leaves can be fermented to prepare an infusion with ideal antioxidant activity. The aim of this study was to investigate and to determine the influence of solid-phase fermentation of different durations on the variation of polyphenols in the leaves of fireweed. Laboratory experiments were conducted in 2017-2018. The leaves of fireweed, naturally growing, were fermented for different periods of time: not fermented (control) and fermented for 24 and 48 h. The evaluation of polyphenols and antioxidant activity in leaves was performed using high- performance liquid chromatography (HPLC). Additionally, principal component analysis was used to characterize differences in bioactive compounds between fireweed samples fermented at different durations. Solid-phase fermented leaves were characterized by higher contents of oenothein B, quercetin and benzoic acid but had lower contents of quercetin-3-O-rutinoside, luteolin and chlorogenic and gallic acids. Antioxidant activity in short- (24 h) and long-term (48 h) fermentation (compared to control) gave the highest level of regression in 2017, but in 2018 the effect was observed only with short-term fermentation and control. In conclusion, solid-phase fermentation can be used to modulate biologically active compounds in fireweed leaves.

Inhibitory mechanism of lactoferrin on antibacterial activity of oenothein B: isothermal titration calorimetry and computational docking simulation.

BACKGROUND: Many foods contain proteins and polyphenols, but there is a poor understanding of the nature of the inhibitory effect of protein on the biologic activity of polyphenols. The inhibitory mechanism of the food protein lactoferrin on the antibacterial activity of oligomeric ellagitannin oenothein B (OeB) was investigated using fluorescence quenching, isothermal titration calorimetry (ITC), circular dichroism (CD) measurement and molecular docking. RESULTS: The antibacterial activity of OeB against Staphylococcus aureus was inhibited by lactoferrin, which was retained at about 60%. An interaction study revealed that an interaction occurred between OeB and lactoferrin. Thermodynamic analyses indicate that the binding process was spontaneous, and the main driving forces were based on electrostatic interactions that contributed to a high interaction affinity between OeB and lactoferrin. Furthermore, CD spectra provided insights into conformational changes of lactoferrin. Finally, molecular docking analysis provided a visual representation of a single binding site where OeB interacted with specific amino acid residues located at the active site of lactoferrin. In particular, due to the unique macrocyclic structure and rigid ring structure of OeB, a small number of hydroxyl groups in the rigid structure of OeB interacted with the amino acid of lactoferrin while most of the phenolic hydroxyl groups were not associated with lactoferrin. CONCLUSION: Our study provides a theoretical basis for the use of OeB as an antibacterial substance that can be used in nutraceuticals and pharmaceutical products. © 2020 Society of Chemical Industry.

Investigation on the Interaction Behavior Between Oenothein B and Pepsin by Isothermal Titration Calorimetry and Spectral Studies.

Oenothein B (OeB) is a dimeric macrocyclic ellagitannin isolated from Herbs and fruits that have a variety of biological activities. In order to better understand the effect of OeB on the activity of the digestive enzyme pepsin, interactions between OeB and pepsin were investigated in vitro under simulated physiological conditions based on enzyme inhibition studies, fluorescence, isothermal titration calorimetry, CD, and molecular docking. It was found OeB is an effective inhibitor of pepsin, likely acting in a reversible manner through both competitive and noncompetitive inhibition. Fluorescence quenching of pepsin by OeB was a static quenching. CD spectra showed the addition of OeB causes the main chain of pepsin to loosen and expand and the partial ß-sheet structure to be converted to a disordered structure. Isothermal titration calorimetry and docking studies revealed the main binding mechanism of OeB and pepsin was through noncovalent interactions, hydrophobic interactions with OeB and the internal hydrophobic group of pepsin, and then hydrogen bonding between OeB and the Val243 and Asp77 residues of pepsin. Noncovalent bonds between OeB and pepsin change the polarity and structure of enzymes, decreasing enzymatic activity. Compared with small molecular polyphenols, OeB has a weaker hydrophobic interaction with pepsin and less effect on the secondary structure of pepsin. These findings are the first direct elucidation of the interactions between the oligomer ellagitannin OeB and pepsin, further contributing to understanding binding between oligomer ellagitannins and digestive enzymes. PRACTICAL APPLICATION: The results of this study indicate that the interaction between OeB and pepsin has a certain inhibitory effect on pepsin. In order to reduce the impact of OeB on human digestion and its own activities, nano-encapsulation technology can be used in the future to protect oligomeric ellagitannin such as OeB.

Variability of polyphenols and volatiles during fruit development of three pitanga (Eugenia uniflora L.) biotypes.

Changes in volatile constituents and phenolic compounds were investigated during fruit development of three pitanga biotypes. Constituents were submitted to multivariate analysis and fruit samples were differentiated by selina-1,3,7(11)-trien-8-one (38.2 ±â€¯2.9%) and its epoxide (26.4 ±â€¯7.2%) for the red-orange biotype; by curzerene (15.04 ±â€¯2.1%) and atractylone (8.47 ±â€¯2.1%) for the red biotype; and by spathulenol (3.7 ±â€¯0.8%) and germacrone (54.7 ±â€¯3.1%) for the purple biotype. Hydrolysable tannins such as mono-O-galloyl-d-glucose, 1,2,6-tri-O-galloyl-ß-d-glucose, tellimagrandin II, and eugeniflorin D2 were identified, as well as oenothein B as the major compound (32.43 ±â€¯7.1 mg/g dry fruit). During pitanga's maturation, anthocyanin content increased, while flavonoid and tannin contents decreased. Higher contents of the majority of phenolic compounds occurred in the red-orange biotype. Biosynthesis of phenolic compounds was influenced by biotype and degree of maturation, whereas chemovariation in essential oil constituents was mainly due to biotypes, thus confirming essential oil chemotypes of E. uniflora.

Oenothein B, dimeric hydrolysable tannin inhibiting HCV invasion from Oenothera erythrosepala.

The envelope proteins of the hepatitis C virus (HCV), E1 and E2, have been revealed to be essential for invasion of HCV. Thus, we were engaged in the search for the inhibitors against HCV invasion through the assay system using the model virus expressing recombinant HCV envelopes, E1 and E2. Now, we disclosed dimeric hydrolysable tannin oenothein B (1) from MeOH extract of Oenothera erythrosepala as an active principle for inhibition of HCV invasion and its potency was almost the same as that of monomeric hydrolysable tannin, tellimagrandin I (2). Furthermore, by use of stereoselectively prepared 1-ß- and 1-α-O-methyl tellimagrandin Is (4 and 5), the introduction of methyl moiety into 1-hydroxy group of 2 was clarified to result in slightly reduction of activity and ß-isomer was revealed to exhibit a little stronger activity than α-one.

Oenothein B inhibits human non-small cell lung cancer A549 cell proliferation by ROS-mediated PI3K/Akt/NF-κB signaling pathway.

Oenothein B has a wide range of biological activities. The present study probed into the underlying mechanism on how Oenothein B inhibits the proliferation of a lung cancer line A549. Our results showed that Oenothein B effectively inhibited the proliferation of A549 cells by inducing apoptosis and arresting cells at G1 stage. Furthermore, Oenothein B not only increased the level of intracellular reactive oxygen species (ROS), but also induced the upregulation of intracellular apoptotic triggers (cleavage caspase-3, PARP, cytochrome c level in the cytosol, Bax). Moreover, ROS inhibitor (N-acetyl-L-cystein, NAC) and PI3K agonist (Insulin-like growth factor 1, IGF-1) could resist cell proliferation inhibition induced by Oenothein B, respectively. ROS inhibitor significantly abrogated the activation of caspase 3/7 and 9 in the presence of Oenothein B. Additionally, suppression of p-PI3K and p-Akt, p-NF-κB by Oenothein B could be compensated by treatment with ROS inhibitor. To summarize, these results demonstrated that Oenothein B was able to prevent cell proliferation probably via ROS-mediated PI3K/Akt/NF-κB signaling pathway.