Estrogens and congeners from spent hops (Humulus lupulus)

Dihydrostilbenes and flavonoids from whole plants of Jacobaea vulgaris

The isolation of previously undescribed 12 compounds from the MeOH extract of Jacobaea vulgaris whole plants is disclosed, comprising 11 dihydrostilbenes (1-11) and one flavanone (12), and eight known compounds (six flavonoids, one dihydrostilbene, and one caffeoylquinic acid). Structural elucidation employed spectroscopic methods, including 1D and 2D NMR spectroscopy, HRESIMS, and ECD calculations. Evaluation of the compounds' effects on PCSK9 and LDLR mRNA expression revealed that compounds 1 and 3 downregulated PCSK9 mRNA while increasing LDLR mRNA expression, suggesting potential cholesterol-lowering properties.

Breast cancer prevention with liquiritigenin from licorice through the inhibition of aromatase and protein biosynthesis in high-risk women's breast tissue

Breast cancer risk continues to increase post menopause. Anti-estrogen therapies are available to prevent postmenopausal breast cancer in high-risk women. However, their adverse effects have reduced acceptability and overall success in cancer prevention. Natural products such as hops (Humulus lupulus) and three pharmacopeial licorice (Glycyrrhiza) species have demonstrated estrogenic and chemopreventive properties, but little is known regarding their effects on aromatase expression and activity as well as pro-proliferation pathways in human breast tissue. We show that Gycyrrhiza inflata (GI) has the highest aromatase inhibition potency among these plant extracts. Moreover, phytoestrogens such as liquiritigenin which is common in all licorice species have potent aromatase inhibitory activity, which is further supported by computational docking of their structures in the binding pocket of aromatase. In addition, GI extract and liquiritigenin suppress aromatase expression in the breast tissue of high-risk postmenopausal women. Although liquiritigenin has estrogenic effects in vitro, with preferential activity through estrogen receptor (ER)-β, it reduces estradiol-induced uterine growth in vivo. It downregulates RNA translation, protein biosynthesis, and metabolism in high-risk women's breast tissue. Finally, it reduces the rate of MCF-7 cell proliferation, with repeated dosing. Collectively, these data suggest that liquiritigenin has breast cancer prevention potential for high-risk postmenopausal women.

Medicinal Plants Used for Anxiety, Depression, or Stress Treatment: An Update

Depression, anxiety, stress, and other mental disorders, which are on the rise worldwide, are indications that pharmacological therapy can have serious adverse effects, which is why many patients prefer to use herbal products to treat these symptoms. Here, we reviewed plants and products derived from them that are commonly used for the above indications, focusing on clinical data and safety profiles. While lavender, hops, maypop, lemon balm, and valerian have consistently been shown in clinical trials to relieve mild forms of neurological disorders, particularly depression, anxiety, and stress, currently available data do not fully support the use of peppermint for anxiety disorders and depression. Recent studies support the use of saffron for depression; however, its toxicological profile raises safety concerns. St. John’s wort is effective in alleviating mild to moderate depression; however, careful use is necessary particularly due to possible interactions with other drugs. In conclusion, more studies are needed to validate the mechanism of action so that these plants can be used successfully and safely to alleviate or eliminate various mental disorders.

Progress of isolation, chemical synthesis and biological activities of natural chalcones bearing 2-hydroxy-3-methyl-3-butenyl group

Chalcones have a three-carbon α,β-unsaturated carbonyl system composed of two phenolic rings. Many chalcones have shown broad spectrum of biological activities with clinical potentials against various diseases. They are usually abundant in seeds, fruit skin, bark and flowers of most edible plants. Among them, chalcones bearing 2-hydroxy-3-methyl-3-butenyl (HMB) group have been reported several times in the past few decades due to their novel scaffolds and numerous interesting biological activities. In this paper, we reviewed the isolation of twelve natural chalcones and a natural chalcone-type compound bearing 2-hydroxy-3-methyl-3-butenyl group discovered so far, and reviewed their synthesis methods and biological activities reported in the literature. We anticipate that this review will inspire further research of natural chalcones.

Synthesis of Human Phase I and Phase II Metabolites of Hop (Humulus lupulus) Prenylated Flavonoids

Hop prenylated flavonoids have been investigated for their in vivo activities due to their broad spectrum of positive health effects. Previous studies on the metabolism of xanthohumol using untargeted methods have found that it is first degraded into 8-prenylnaringenin and 6-prenylnaringenin, by spontaneous cyclisation into isoxanthohumol, and subsequently demethylated by gut bacteria. Further combinations of metabolism by hydroxylation, sulfation, and glucuronidation result in an unknown number of isomers. Most investigations involving the analysis of prenylated flavonoids used surrogate or untargeted approaches in metabolite identification, which is prone to errors in absolute identification. Here, we present a synthetic approach to obtaining reference standards for the identification of human xanthohumol metabolites. The synthesised metabolites were subsequently analysed by qTOF LC-MS/MS, and some were matched to a human blood sample obtained after the consumption of 43 mg of micellarised xanthohumol. Additionally, isomers of the reference standards were identified due to their having the same mass fragmentation pattern and different retention times. Overall, the methods unequivocally identified the metabolites of xanthohumol that are present in the blood circulatory system. Lastly, in vitro bioactive testing should be applied using metabolites and not original compounds, as free compounds are scarcely found in human blood.

Herbal Products Used in Menopause and for Gynecological Disorders

Herbal products are often used as an alternative to pharmacological therapy. Menopausal symptoms and gynecological disorders (such as premenstrual syndrome and dysmenorrhea) are the indications where pharmacological therapy may have serious adverse events, hence many women prefer to use herbal products to help with these symptoms. Here, we reviewed plants and derived products, which are commonly used for the abovementioned indications, focusing on clinical data, safely profile and whether or not their use is justified. We noted that limited data are available on the use of some plants for alleviating the symptoms of menopause and gynecological disorders. While black cohosh (Cimicifuga racemose) and red clover (Trifolium pretense) were consistently shown to help reduce menopausal symptoms in clinical studies, currently available data do not fully support the use of fenugreek (Trigonella foenum-graecum), hops (Humulus lupulus), valerian (Valeriana officinalis), and soybean (Glycine max and Glycine soja) for this indication. For premenstrual syndrome and premenstrual dysphoric disorder, chaste tree (Vitex agnus-castus) shows effectiveness, but more clinical studies are needed to confirm such effect upon the use of evening primrose (Oenothera biennis).

Amorphous solid dispersions in poly(ε-caprolactone)/xanthohumol bioactive blends: physicochemical and mechanical characterization

This paper reports the obtention of amorphous solid dispersions (ASDs) of xanthohumol (XH) in PCL containing up to 50 wt% of the bioactive compound in the amorphous form thanks to the advantageous specific interactions established in this system. The miscibility of the PCL/XH blends was investigated using DSC. Melting point depression analysis yielded a negative interaction parameter indicating the occurrence of favorable inter-association interactions. XRD analyses performed at room temperature agree with the crystallinity results obtained on the heating runs performed by DSC. FTIR spectroscopy reveals strong C[double bond, length as m-dash]OO-H specific interactions between the hydroxyl groups of XH and the carbonyl groups of PCL. The AFM analysis of the blends obtained by spin-coating shows the variation of crystalline morphology with composition. Finally, tensile tests reveal high toughness retention for the blends in which XH can be dispersed in the amorphous form (containing up to 50 wt% XH). In summary, PCL is a convenient matrix to disperse XH in the amorphous form, bringing the possibility of obtaining completely amorphous bioactive materials suitable for the development of non-stiff biomedical devices.

Naturally occurring prenylated chalcones from plants: structural diversity, distribution, activities and biosynthesis

Covering: up to July 2020Naturally occurring chalcones carrying up to three modified or unmodified C5-, C10-, and C15-prenyl moieties on both rings A and B as well as at the α- and β-carbons are widely distributed in plants of the families of Fabaceae, Moraceae, Zingiberaceae and Cannabaceae. Xanthohumol and isobavachalcone being the most investigated representatives, exhibit diverse and remarkable biological and pharmacological activities. The present review deals with their structural characters, biological activities and occurrence in the plant kingdom. Biosynthesis of prenylated chalcones and metabolism of xanthohumol are also discussed.

Seven new prenylated flavanones from the roots of Sophora flavescens and their anti-proliferative activities

Aiming to discover potent anti-proliferative agents from the roots of Sophora flavescens, seven new prenylated flavanones were isolated, along with 16 known compounds. Their structures were elucidated by interpretation of their spectroscopic data (1D and 2D NMR, UV, IR, CD, and HRESIMS) and comparison to literature data. In the in vitro assay, 21 showed anti-proliferative activity against human hepatoma cells (HepG2). Studies of its mechanism revealed that 21 could significantly activate autophagic flux and trigger ROS release in HepG2 cells. Western blot experiments demonstrated that 21 could activate the key signaling protein of autophagy and ROS, while it does not affect the main protein of the apoptosis signaling pathway. These results suggested that 21 mediates its anti-proliferative effects through autophagic cell death, which is apoptosis-independent.

Recent patents on therapeutic activities of xanthohumol: a prenylated chalconoid from hops (Humulus lupulus L.)

There is expanding proof that specific natural compounds found in plants have additional conventional medicinal properties. One such compound is xanthohumol (XN), which is being explored as an antimicrobial, anticarcinogenic, antidiabetic and anti-inflammatory agent - aside from its utilization in dealing with conditions like autism, bone and skin improvement and microbial infections, lipid-related illnesses, and so on. XN is reported to suppress the uncontrolled production of inflammatory mediators responsible for diseases including cardiovascular disease, neurodegeneration and tumors. Further, it is accounted to limit adipogenesis and control obesity by focusing on principal adipocyte marker proteins. It is most generally utilized in the brewing industry as an additive and flavoring agent to add bitterness and aroma to beer. Present investigation sum up the patents filed in most recent 2 years on development of different pharmaceutical mixes and strategies dependent on various therapeutic potentials of XN.

SAR Study on Estrogen Receptor α/β Activity of (Iso)flavonoids: Importance of Prenylation, C-Ring (Un)Saturation, and Hydroxyl Substituents

Many botanicals used for women's health contain estrogenic (iso)flavonoids. The literature suggests that estrogen receptor beta (ERβ) activity can counterbalance estrogen receptor alpha (ERα)-mediated proliferation, thus providing a better safety profile. A structure-activity relationship study of (iso)flavonoids was conducted to identify ERβ-preferential structures, overall estrogenic activity, and ER subtype estrogenic activity of botanicals containing these (iso)flavonoids. Results showed that flavonoids with prenylation on C8 position increased estrogenic activity. C8-prenylated flavonoids with C2-C3 unsaturation resulted in increased ERβ potency and selectivity [e.g., 8-prenylapigenin (8-PA), EC₅₀ (ERβ): 0.0035 ± 0.00040 μM], whereas 4'-methoxy or C3 hydroxy groups reduced activity [e.g., icaritin, EC₅₀ (ERβ): 1.7 ± 0.70 μM]. However, nonprenylated and C2-C3 unsaturated isoflavonoids showed increased ERβ estrogenic activity [e.g., genistein, EC₅₀ (ERβ): 0.0022 ± 0.0004 μM]. Licorice (Glycyrrhiza inflata, [EC₅₀ (ERα): 1.1 ± 0.20; (ERβ): 0.60 ± 0.20 μg/mL], containing 8-PA, and red clover [EC₅₀ (ERα): 1.8 ± 0.20; (ERβ): 0.45 ± 0.10 μg/mL], with genistein, showed ERβ-preferential activity as opposed to hops [EC₅₀ (ERα): 0.030 ± 0.010; (ERβ): 0.50 ± 0.050 μg/mL] and Epimedium sagittatum [EC₅₀ (ERα): 3.2 ± 0.20; (ERβ): 2.5 ± 0.090 μg/mL], containing 8-prenylnaringenin and icaritin, respectively. Botanicals with ERβ-preferential flavonoids could plausibly contribute to ERβ-protective benefits in menopausal women.

Semi-Synthetic Approach Leading to 8-Prenylnaringenin and 6-Prenylnaringenin: Optimization of the Microwave-Assisted Demethylation of Xanthohumol Using Design of Experiments

The isomers 8-prenylnaringenin and 6-prenylnaringenin, both secondary metabolites occurring in hops, show interesting biological effects, like estrogen-like, cytotoxic, or neuro regenerative activities. Accordingly, abundant sources for this special flavonoids are needed. Extraction is not recommended due to the very low amounts present in plants and different synthesis approaches are characterized by modest yields, multiple steps, the use of expensive chemicals, or an elaborate synthesis. An easy synthesis strategy is the demethylation of xanthohumol, which is available due to hop extraction industry, using lithium chloride and dimethylformamide, but byproducts and low yield did not make this feasible until now. In this study, the demethylation of xanthohumol to 8-prenylnaringenin and 6-prenylnaringenin is described the first time and this reaction was optimized using Design of Experiment and microwave irradiation. With the optimized conditions—temperature 198 °C, 55 eq. lithium chloride, and a reaction time of 9 min, a final yield of 76% of both prenylated flavonoids is reached.

Effect of a new herbal composition comprised of red clover and hop extract on human endothelial cell damage and vasorelaxant activity

Hormone replacement therapy may cause various side effects, including enhancing the risk of cardiovascular disease (CVD) in postmenopausal women. Here, we investigated the effect of red clover and hop extract combination (RHEC) on estrogen receptor (ER) binding and endothelial function of human umbilical vein endothelial cells (HUVECs) to develop an herbal agent for reducing the risk of CVDs. In ER competitor assay, RHEC showed binding affinity toward ERα and ERβ with IC50 values of 5.92 µg/ml and 1.66 µg/ml, respectively. In HUVECs, RHEC significantly increased the cell viability and reduced the reactive oxygen species production against oxidative stress-induced damage. We also showed that RHEC increased the NO production through upregulating the endothelial nitric oxide synthase expression via ER activation in estrogen depleted condition. In particular, RHEC showed greater efficacy with increase in NO and decrease in endothelin-1 than red clover or hop treatment alone. Additionally, 0.3-0.5 mg/ml of RHEC-induced vasorelaxation of rat aortic rings precontracted by phenylephrine. PRACTICAL APPLICATIONS: Recently, a large interest has grown in the synergistic effects of phytochemicals for better therapies to treat various diseases. Red clover and hop are well-known edible plants which are widely used to help relieve postmenopausal symptoms including CVD. However, their combination has not been studied so far. For the first time, we demonstrated that RHEC, a new herbal combination comprising the extracts from red clover and hop, appeared to be effective in protection of endothelial function against oxidative stress and estrogen depletion. Therefore, RHEC could be a potent herbal agent for reducing the risk of endothelial damage.

Formation of Prenylated Chalcone Xanthohumol Cocrystals: Single Crystal X-Ray Diffraction, Vibrational Spectroscopic Study Coupled with Multivariate Analysis

Four novel xanthohumol (XN) cocrystals with pharmaceutically acceptable coformers, such as nicotinamide (NIC), glutarimide (GA), acetamide (AC), and caffeine (CF) in the 1:1 stoichiometry were obtained by the slow evaporation solution growth technique. The structure of the cocrystals was determined by single crystal X-ray diffraction. The analysis of packing and interactions in the crystal lattice revealed that molecules in the target cocrystals were packed into almost flat layers, formed by the O–H⋅⋅⋅O, O–H⋅⋅⋅N, and N–H⋅⋅⋅O-type contacts between the xanthohumol and coformer molecules. The results provided details about synthons responsible for crystal net stabilization and all hydrogen bonds observed in the crystal lattice. The main synthon was formed via the hydrogen bond between the hydroxyl group in the B ring of XN and coformers. The three-dimensional crystal lattice was stabilized by the hydrogen XN−XN interactions whereas the π–π stacking interactions played an additional role in layer binding, with the exception of low quality cocrystals formed with caffeine. Application of FTIR and Raman spectroscopy confirmed that the crystalline phase of obtained cocrystals was not a simple combination of individual components and completely different crystal phases resulted from the effect of intermolecular interactions. The multivariate analysis showed the changes in the spectra, and this technique can be applied in a combination with vibrational spectroscopy for fast screening of new crystal phases. Additionally, the solubility studies of pure XN and its cocrystals exhibited a 2.6-fold enhancement in XN solubility in aqueous solution for XN–AC and, to a lesser extent, for other cocrystals.

Formation of (2R)- and (2S)-8-Prenylnaringenin Glucuronides by Human UDP-Glucuronosyltransferases

Occurring in hops (Humulus lupulus) and beer as a racemic mixture, (2R,2S)-8-prenylnaringenin (8-PN) is a potent phytoestrogen in hop dietary supplements used by women as alternatives to conventional hormone therapy. With a half-life exceeding 20 h, 8-PN is excreted primarily as 8-PN-7-O-glucuronide or 8-PN-4'-O-glucuronide. Human liver microsomes and 11 recombinant human UDP-glucuronosyltransferases (UGTs) were used to catalyze the formation of the two oxygen-linked glucuronides of purified (2R)-8-PN and (2S)-8-PN, which were subsequently identified using mass spectrometry and nuclear magnetic resonance spectroscopy. Formation of (2R)- and (2S)-8-PN-7-O-glucuronides predominated over the 8-PN-4'-O-glucuronides except for intestinal UGT1A10, which formed more (2S)-8-PN-4'-O-glucuronide. (2R)-8-PN was a better substrate for all 11 UGTs except for UGT1A1, which formed more of both (2S)-8-PN glucuronides than (2R)-8-PN glucuronides. Although several UGTs conjugated both enantiomers of 8-PN, some conjugated just one enantiomer, suggesting that human phenotypic variation might affect the routes of metabolism of this chiral estrogenic constituent of hops.

Two new alkaloids isolated from traditional Chinese medicine Binglang the fruit of Areca catechu

Binglang, the fruit of Areca catechu L, has a long history as an important Chinese herbal medicine. Two new alkaloids (1 and 2), along with forty-one known compounds (3-43) were isolated from the dried fruit of Areca catechu L. The structures were elucidated on basis of the IR, UV, MS and 1D, 2D NMR spectroscopic data. Compounds 26 and 33 showed weak cytotoxicity against human gastric cancer cell line (BGC-823) with IC₅₀ of 15.91 μM and 20.13 μM, respectively.

The Multiple Biological Targets of Hops and Bioactive Compounds

Botanical dietary supplements for women's health are increasingly popular. Older women tend to take botanical supplements such as hops as natural alternatives to traditional hormone therapy to relieve menopausal symptoms. Especially extracts from spent hops, the plant material remaining after beer brewing, are enriched in bioactive prenylated flavonoids that correlate with the health benefits of the plant. The chalcone xanthohumol (XH) is the major prenylated flavonoid in spent hops. Other less abundant but important bioactive prenylated flavonoids are isoxanthohumol (IX), 8-prenylnaringenin (8-PN), and 6-prenylnaringenin (6-PN). Pharmacokinetic studies revealed that these flavonoids are conjugated rapidly with glucuronic acid. XH also undergoes phase I metabolism in vivo to form IX, 8-PN, and 6-PN. Several hop constituents are responsible for distinct effects linked to multiple biological targets, including hormonal, metabolic, inflammatory, and epigenetic pathways. 8-PN is one of the most potent phytoestrogens and is responsible for hops' estrogenic activities. Hops also inhibit aromatase activity, which is linked to 8-PN. The weak electrophile, XH, can activate the Keap1-Nrf2 pathway and turn on the synthesis of detoxification enzymes such as NAD(P)H-quinone oxidoreductase 1 and glutathione S-transferase. XH also alkylates IKK and NF-κB, resulting in anti-inflammatory activity. Antiobesity activities have been described for XH and XH-rich hop extracts likely through activation of AMP-activated protein kinase signaling pathways. Hop extracts modulate the estrogen chemical carcinogenesis pathway by enhancing P450 1A1 detoxification. The mechanism appears to involve activation of the aryl hydrocarbon receptor (AhR) by the AhR agonist, 6-PN, leading to degradation of the estrogen receptor. Finally, prenylated phenols from hops are known inhibitors of P450 1A1/2; P450 1B1; and P450 2C8, 2C9, and 2C19. Understanding the biological targets of hop dietary supplements and their phytoconstituents will ultimately lead to standardized botanical products with higher efficacy, safety, and chemopreventive properties.

Xanthohumol inhibits tau protein aggregation and protects cells against tau aggregates

Xanthohumol is shown to interact with tau protein and inhibit its aggregation.

Molecular modeling and in vitro approaches towards cholinesterase inhibitory effect of some natural xanthohumol, naringenin, and acyl phloroglucinol derivatives

BACKGROUND

Many natural products, particularly phenolic compounds, have been reported to have a strong inhibition against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the key enzymes in the pathology of Alzheimer's disease (AD).

HYPOTHESIS

Therefore, we hypothesized that some xanthahumol, naringenin, and acyl phloroglucinol derivatives (1-14) isolated from Humulus lupulus L. (hops) may have an inhibitory potential against AChE and BChE.

METHODS

Inhibitory potential of compounds 1-14 were tested against AChE and BChE using ELISA microtiter assay. Different molecular docking simulations, including IFD and GOLD protocols, were implemented to verify the interactions between the ligands and the active site amino acids and also their binding energies inside the catalytic crevices of AChE and BChE. ADME/Tox analysis were used to determine pharmacological activities of the compounds.

RESULTS

Among them, 3‑hydroxy‑xanthohumol (IC₅₀ = 51.25 ± 0.88 µM) and xanthohumol (IC₅₀ = 71.34 ± 2.09 µM), displayed a moderate AChE inhibition in comparison to that of the reference (galanthamine, IC₅₀ = 2.52 ± 0.15 µM). In addition to 3‑hydroxy‑xanthohumol (IC₅₀ = 63.07 ± 3.76 µM) and xanthohumol (IC₅₀ = 32.67 ± 2.82 µM), 8-prenylnaringenin (IC₅₀ = 86.58 ± 3.74 µM) also showed micromolar-range inhibition against BChE (galanthamine, IC₅₀ = 46.58 ± 0.91 µM). Rest of the compounds were found to be either inactive or having inhibition below 50%. Prediction of pharmacokinetic studies suggested that all the ligands revealed acceptable drug-like profiles. Docking simulations demonstrate not only the prediction of ligand binding energies of the compounds inside the catalytic domains of the targets, but also highlight the critical amino acids contributing to stabilizations of the ligands.

CONCLUSION

Our findings revealed that xanthohumol in particular could be considered as lead molecule to explore new cholinesterase inhibitors for AD.

Acid-Base Properties of Xanthohumol: A Computational and Experimental Investigation

UV-vis spectrophotometry has been applied to determine acid dissociation constants of the prenylated chalcone xanthohumol. The pK_a values were compared with those derived from pH-metric titrations. The order of the deprotonation site in the xanthohumol molecule was estimated by quantum mechanical calculations as 2'-OH, 4'-OH, and 4-OH. Furthermore, the electronic and spectroscopic properties of xanthohumol have been investigated on the basis of the time-dependent density functional theory (TDDFT). The TDDFT method, combined with a hybrid exchange-correlation functional using the B3LYP and CAM-B3LYP levels of theory in conjunction with the SMD solvation model, was used to optimize all geometries and predict the excitation energies of the neutral form and ionized species of the chalcone depending on pH value. The computed results were in good agreement with the experimental data. Consideration of the acid-base profile in conjunction with other molecular properties has a great importance and has the potential to be used to further improve the bioavailability of xanthohumol.

Characteristic α-Acid Derivatives from Humulus lupulus with Antineuroinflammatory Activities

Twenty compounds, including 14 new α-acid derivatives, a new chromone, and five known compounds, were identified from the pistillate inflorescence of Humulus lupulus (hops), and their structures were elucidated via physical data analysis. The absolute configurations of new α-acid derivatives 1-11b were determined by comparing their computed and experimental electronic circular dichroism spectra using TDDFT and NMR spectroscopic data. A putative biosynthetic pathway for the identified components was deduced. Their antineuroinflammatory effects were assayed systematically, and their structure-activity relationships are discussed briefly. Among the identified compounds, compound 14 displayed moderate inhibitory effects against nitric oxide production with an IC₅₀ value of 7.92 μM.

Evaluation of estrogenic potency of a standardized hops extract on mammary gland biology and on MNU-induced mammary tumor growth in rats

Supplements with estrogenic activities are intensively investigated as potential alternatives for the treatment of menopausal symptoms. These investigations include studies on their safety regarding potential breast cancer risks. Therefore, the aim of this study was to assess whether or not a standardized hops (Humulus lupulus) extract, containing 0.42% of the estrogenic flavanone, 8-prenylnaringenin, would stimulate growth of methyl-nitrosourea (MNU) induced mammary cancer in ovariectomized (OVX) Sprague-Dawley (SD) rats or would impact on the proliferative activity within the normal mammary gland of Wistar rats. To induce tumorigenesis SD-rats received an intraperitoneal injection of 50mg/kg body weight of MNU on postnatal days PND 50 and 52. 28days later animals were OVX or were SHAM operated (positive control) and randomly allocated and maintained for 140days on either a phytoestrogen-free placebo diet (SHAM and negative control) or on the hops fortified diet. For the investigations in the normal mammary gland young adult Wistar rats were bilaterally OVX and randomly allocated to a control group fed to a phytoestrogen-free diet, or to a diet supplemented either with E₂-benzoate or the hops extract. As a major result, the tumor incidence was 15% (3 tumors totally) in OVX controls, whereas it was 85% (39 tumors totally) in SHAM operated positive controls. No tumors were detectable in the hops group. In addition, no estrogenic activity of the hops extract was detectable in uterus and liver of these animals. In investigations on the normal mammary gland, no impact of hops extract on the expression of estrogen dependent proliferation markers or of progesterone receptor became apparent. In conclusion, the lack of growth stimulation of MNU-induced breast cancer in OVX SD-rats and the lack of stimulation proliferative events in the normal mammary gland of OVX Wistar rats by standardized hops extracts provides an important piece of evidence regarding the safety of these extracts in the management of menopausal symptoms.

Deterrent activity of hops flavonoids and their derivatives against stored product pests

Five flavonoids from hops, two of their derivatives, along with naringenin used as a model compound, were tested for their antifeedant activity against three coleopteran stored product pests: Sitophilus granarius L., Tribolium confusum Duv. and Trogoderma granarium Everts. The introduction, into the tested flavonoid molecules, of additional structural fragments such as prenyl or dimethylpyran moiety, is proposed to significantly alter the deterrent activity of the compounds. The prenyl moiety in flavonoids increased the deterrent activity of these compounds in all three of the grain feeding species used in the tests. It is also concluded that the introduction of dimethylpyran moiety to the flavonoid structure increases its deterrent activity in S. granarius and T. confusum, but in one of the test insects, T. granarium, an increased feeding was observed in response to the introduction of dimethylpyran moiety to the flavonoid structure.

DESIGNER Extracts as Tools to Balance Estrogenic and Chemopreventive Activities of Botanicals for Women's Health

Botanical dietary supplements contain multiple bioactive compounds that target numerous biological pathways. The lack of uniform standardization requirements is one reason that inconsistent clinical effects are reported frequently. The multifaceted biological interactions of active principles can be disentangled by a coupled pharmacological/phytochemical approach using specialized ("knock-out") extracts. This is demonstrated for hops, a botanical for menopausal symptom management. Employing targeted, adsorbent-free countercurrent separation, Humulus lupulus extracts were designed for pre- and postmenopausal women by containing various amounts of the phytoestrogen 8-prenylnaringenin (8-PN) and the chemopreventive constituent xanthohumol (XH). Analysis of their estrogenic (alkaline phosphatase), chemopreventive (NAD(P)H-quinone oxidoreductase 1 [NQO1]), and cytotoxic bioactivities revealed that the estrogenicity of hops is a function of 8-PN, whereas their NQO1 induction and cytotoxic properties depend on XH levels. Antagonization of the estrogenicity of 8-PN by elevated XH concentrations provided evidence for the interdependence of the biological effects. A designed postmenopausal hop extract was prepared to balance 8-PN and XH levels for both estrogenic and chemopreventive properties. An extract designed for premenopausal women contains reduced 8-PN levels and high XH concentrations to minimize estrogenic while retaining chemopreventive properties. This study demonstrates the feasibility of modulating the concentrations of bioactive compounds in botanical extracts for potentially improved efficacy and safety.

Gynecomastia and hormones

Gynecomastia-the enlargement of male breast tissue in men-is a common finding, frequently observed in newborns, adolescents, and old men. Physiological gynecomastia, occurring in almost 25 % of cases, is benign and self-limited; on the other hand, several conditions and drugs may induce proliferation of male breast tissue. True gynecomastia is a common feature often related to estrogen excess and/or androgen deficiency as a consequence of different endocrine disorders. Biochemical evaluation should be performed once physiological or iatrogenic gynecomastia has been ruled out. Non-endocrine illnesses, including liver failure and chronic kidney disease, are another cause of gynecomastia which should be considered. Treating the underlying disease or discontinuing medications might resolve gynecomastia, although the psychosocial burden of this condition might require different and careful consideration.

Botanicals and Their Bioactive Phytochemicals for Women's Health

Botanical dietary supplements are increasingly popular for women's health, particularly for older women. The specific botanicals women take vary as a function of age. Younger women will use botanicals for urinary tract infections, especially Vaccinium macrocarpon (cranberry), where there is evidence for efficacy. Botanical dietary supplements for premenstrual syndrome (PMS) are less commonly used, and rigorous clinical trials have not been done. Some examples include Vitex agnus-castus (chasteberry), Angelica sinensis (dong quai), Viburnum opulus/prunifolium (cramp bark and black haw), and Zingiber officinale (ginger). Pregnant women have also used ginger for relief from nausea. Natural galactagogues for lactating women include Trigonella foenum-graecum (fenugreek) and Silybum marianum (milk thistle); however, rigorous safety and efficacy studies are lacking. Older women suffering menopausal symptoms are increasingly likely to use botanicals, especially since the Women's Health Initiative showed an increased risk for breast cancer associated with traditional hormone therapy. Serotonergic mechanisms similar to antidepressants have been proposed for Actaea/Cimicifuga racemosa (black cohosh) and Valeriana officinalis (valerian). Plant extracts with estrogenic activities for menopausal symptom relief include Glycine max (soy), Trifolium pratense (red clover), Pueraria lobata (kudzu), Humulus lupulus (hops), Glycyrrhiza species (licorice), Rheum rhaponticum (rhubarb), Vitex agnus-castus (chasteberry), Linum usitatissimum (flaxseed), Epimedium species (herba Epimedii, horny goat weed), and Medicago sativa (alfalfa). Some of the estrogenic botanicals have also been shown to have protective effects against osteoporosis. Several of these botanicals could have additional breast cancer preventive effects linked to hormonal, chemical, inflammatory, and/or epigenetic pathways. Finally, although botanicals are perceived as natural safe remedies, it is important for women and their healthcare providers to realize that they have not been rigorously tested for potential toxic effects and/or drug/botanical interactions. Understanding the mechanism of action of these supplements used for women's health will ultimately lead to standardized botanical products with higher efficacy, safety, and chemopreventive properties.

Hop (Humulus lupulus L.) Extract and 6-Prenylnaringenin Induce P450 1A1 Catalyzed Estrogen 2-Hydroxylation

Humulus lupulus L. (hops) is a popular botanical dietary supplement used by women as a sleep aid and for postmenopausal symptom relief. In addition to its efficacy for menopausal symptoms, hops can also modulate the chemical estrogen carcinogenesis pathway and potentially protect women from breast cancer. In the present study, an enriched hop extract and the key bioactive compounds [6-prenylnarigenin (6-PN), 8-prenylnarigenin (8-PN), isoxanthohumol (IX), and xanthohumol (XH)] were tested for their effects on estrogen metabolism in breast cells (MCF-10A and MCF-7). The methoxyestrones (2-/4-MeOE₁) were analyzed as biomarkers for the nontoxic P450 1A1 catalyzed 2-hydroxylation and the genotoxic P450 1B1 catalyzed 4-hydroxylation pathways, respectively. The results indicated that the hop extract and 6-PN preferentially induced the 2-hydroxylation pathway in both cell lines. 8-PN only showed slight up-regulation of metabolism in MCF-7 cells, whereas IX and XH did not have significant effects in either cell line. To further explore the influence of hops and its bioactive marker compounds on P450 1A1/1B1, mRNA expression and ethoxyresorufin O-dealkylase (EROD) activity were measured. The results correlated with the metabolism data and showed that hop extract and 6-PN preferentially enhanced P450 1A1 mRNA expression and increased P450 1A1/1B1 activity. The aryl hydrocarbon receptor (AhR) activation by the isolated compounds was tested using xenobiotic response element (XRE) luciferase construct transfected cells. 6-PN was found to be an AhR agonist that significantly induced XRE activation and inhibited 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced XRE activity. 6-PN mediated induction of EROD activity was also inhibited by the AhR antagonist CH223191. These data show that the hop extract and 6-PN preferentially enhance the nontoxic estrogen 2-hydroxylation pathway through AhR mediated up-regulation of P450 1A1, which further emphasizes the importance of standardization of botanical extracts to multiple chemical markers for both safety and desired bioactivity.

The Bitter Chemodiversity of Hops (Humulus lupulus L.)

To map the chemodiversity of key bitter compounds in hops, a total of 75 different samples collected from the global hop market were analyzed for 117 key bitter tastants by means of a multiparametric HPLC-MS/MSMRM method. Among the compounds detected, 2'',3''-epoxyxanthohumol was detected for the first time in hops and iso¬xantho¬humol M was identified as a marker compound for varieties grown in Germany. Hop ageing experiments in the absence and presence of air oxygen, respectively, were conducted to address the stability of hop-derived compounds during long-term storage.

Induction of NAD(P)H:Quinone Oxidoreductase 1 (NQO1) by Glycyrrhiza Species Used for Women's Health: Differential Effects of the Michael Acceptors Isoliquiritigenin and Licochalcone A

For the alleviation of menopausal symptoms, women frequently turn to botanical dietary supplements, such as licorice and hops. In addition to estrogenic properties, these botanicals could also have chemopreventive effects. We have previously shown that hops and its Michael acceptor xanthohumol (XH) induced the chemoprevention enzyme,

NAD(P)H

quinone oxidoreductase 1 (NQO1), in vitro and in vivo. Licorice species could also induce NQO1, as they contain the Michael acceptors isoliquiritigenin (LigC) found in Glycyrrhiza glabra (GG), G. uralensis (GU), G. inflata (GI), and licochalcone A (LicA) which is only found in GI. These licorice species and hops induced NQO1 activity in murine hepatoma (Hepa1c1c7) cells; hops ≫ GI > GG ≅ GU. Similar to the known chemopreventive compounds curcumin (turmeric), sulforaphane (broccoli), and XH, LigC and LicA were active dose-dependently; sulforaphane ≫ XH > LigC > LicA ≅ curcumin ≫ liquiritigenin (LigF). Induction of the antioxidant response element luciferase in human hepatoma (HepG2-ARE-C8) cells suggested involvement of the Keap1-Nrf2 pathway. GG, GU, and LigC also induced NQO1 in nontumorigenic breast epithelial MCF-10A cells. In female Sprague-Dawley rats treated with GG and GU, LigC and LigF were detected in the liver and mammary gland. GG weakly enhanced NQO1 activity in the mammary tissue but not in the liver. Treatment with LigC alone did not induce NQO1 in vivo most likely due to its conversion to LigF, extensive metabolism, and its low bioavailability in vivo. These data show the chemopreventive potential of licorice species in vitro could be due to LigC and LicA and emphasize the importance of chemical and biological standardization of botanicals used as dietary supplements. Although the in vivo effects in the rat model after four-day treatment are minimal, it must be emphasized that menopausal women take these supplements for extended periods of time and long-term beneficial effects are quite possible.

Real-Time Volumetric Phase Monitoring: Advancing Chemical Analysis by Countercurrent Separation

Countercurrent separation (CCS) utilizes the differential partitioning behavior of analytes between two immiscible liquid phases. We introduce the first platform ("CherryOne") capable of real-time monitoring, metering, and control of the dynamic liquid-liquid CCS process. Automated phase monitoring and volumetrics are made possible with an array of sensors, including the new permittivity-based phase metering apparatus (PMA). Volumetric data for each liquid phase are converted into a dynamic real-time display of stationary phase retention (Sf) and eluent partition coefficients (K), which represent critical parameters of CCS reproducibility. When coupled with the elution-extrusion operational mode (EECCC), automated Sf and K determination empowers untargeted and targeted applications ranging from metabolomic analysis to preparative purifications.

Sensomics analysis of key bitter compounds in the hard resin of hops (Humulus lupulus L.) and their contribution to the bitter profile of Pilsner-type beer

Recent brewing trials indicated the occurrence of valuable bitter compounds in the hard resin fraction of hop. Aiming at the discovery of these compounds, hop's ε-resin was separated by means of a sensory guided fractionation approach and the key taste molecules were identified by means of UV/vis, LC-TOF-MS, and 1D/2D-NMR studies as well as synthetic experiments. Besides a series of literature known xanthohumol derivatives, multifidol glucosides, flavon-3-on glycosides, and p-coumaric acid esters, a total of 11 bitter tastants are reported for the first time, namely, 1",2"-dihydroxanthohumol F, 4'-hydroxytunicatachalcone, isoxantholupon, 1-methoxy-4-prenylphloroglucinol, dihydrocyclohumulohydrochinone, xanthohumols M, N, and P, and isoxanthohumols M, N, and P, respectively. Human sensory analysis revealed low bitter recognition threshold concentrations ranging from 5 (co-multifidol glucopyranoside) to 198 μmol/L (trans-p-coumaric acid ethyl ester) depending on their chemical structure. For the first time, LC-MS/MS quantitation of these taste compounds in Pilsner-type beer, followed by taste re-engineering experiments, revealed the additive contribution of iso-α-acids and the identified hard resin components to be truly necessary and sufficient for constructing the authentic bitter percept of beer. Finally, brewing trails using the ε-resin as the only hop source impressively demonstrated the possibility to produce beverages strongly enriched with prenylated hop flavonoids.

Alkaline phosphatase activity-guided isolation of active compounds and new dammarane-type triterpenes from Cissus quadrangularis hexane extract

ETHNOPHARMACOLOGICAL RELEVANCE

The stem of Cissus quadrangularis L. (CQ) is used in traditional medicine to treat bone fractures and swelling. Anti-osteoporotic activity of CQ hexane extract has been reported, but the active compounds in this extract remain unknown. Thus, we aimed to identify the active compounds in CQ hexane extract using bioassay-guided isolation.

MATERIALS AND METHODS

The CQ hexane extract was fractionated sequentially with benzene, dichloromethane, ethyl acetate, and methanol. The examination of CQ extract and its fractions was guided by bioassays for alkaline phosphatase (ALP) activity during the differentiation of MC3T3-E1 osteoblastic cells. The cells were treated with or without the CQ extract and its fractions for a period of time, and then the stimulatory effect of the alkaline phosphatase enzyme, a bone differentiation marker, was investigated. The compounds obtained were structurally elucidated using spectroscopic techniques and re-evaluated for activity during bone differentiation.

RESULTS

A total of 29 compounds were isolated, viz., triterpenes, fatty acid methyl esters, glycerolipids, steroids, phytols, and cerebrosides. Four new dammarane-type triterpenes were isolated for the first time from nature, and this report is the first to identify this group of compounds from the Vitaceae family. Seven compounds, viz., glycerolipids and squalene, stimulated ALP activity at a dose of 10μg/mL. Moreover, the synergistic effect of these compounds on bone formation was demonstrated.

CONCLUSION

This report describes, for the first time, the isolation of active compounds from CQ hexane extract; these active compounds will be useful for the quality control of extracts from this plant used to treat osteoporosis.

Vibrational spectroscopy and chemometrics for rapid, quantitative analysis of bitter acids in hops (Humulus lupulus)

Hops, Humulus lupulus, are grown worldwide for use in the brewing industry to impart characteristic flavor and aroma to finished beer. Breeders produce many varietal crosses with the aim of improving and diversifying commercial hops varieties. The large number of crosses critical to a successful breeding program imposes high demands on the supporting chemical analytical laboratories. With the aim of reducing the analysis time associated with hops breeding, quantitative partial least-squares regression (PLS-R) models have been produced, relating reference data acquired by the industrial standard HPLC and UV methods, to vibrational spectra of the same, chemically diverse hops sample set. These models, produced from rapidly acquired infrared (IR), near-infrared (NIR), and Raman spectra, were appraised using standard statistical metrics. Results demonstrated that all three spectroscopic methods could be used for screening hops for α-acid, total bitter acids, and cohumulone concentrations in powdered hops. Models generated from Raman and IR spectra also showed potential for use in screening hops varieties for xanthohumol concentrations. NIR analysis was performed using both a standard benchtop spectrometer and a portable NIR spectrometer, with comparable results obtained by both instruments. Finally, some important vibrational features of cohumulone, colupulone, and xanthohumol were assigned using DFT calculations, which allow more insightful interpretation of PLS-R latent variable plots.

K-targeted metabolomic analysis extends chemical subtraction to DESIGNER extracts: selective depletion of extracts of hops (Humulus lupulus)

This study introduces a flexible and compound targeted approach to Deplete and Enrich Select Ingredients to Generate Normalized Extract Resources, generating DESIGNER extracts, by means of chemical subtraction or augmentation of metabolites. Targeting metabolites based on their liquid-liquid partition coefficients (K values), K targeting uses countercurrent separation methodology to remove single or multiple compounds from a chemically complex mixture, according to the following equation: DESIGNER extract = total extract ± target compound(s). Expanding the scope of the recently reported depletion of extracts by immunoaffinity or solid phase liquid chromatography, the present approach allows a more flexible, single- or multi-targeted removal of constituents from complex extracts such as botanicals. Chemical subtraction enables both chemical and biological characterization, including detection of synergism/antagonism by both the subtracted targets and the remaining metabolite mixture, as well as definition of the residual complexity of all fractions. The feasibility of the DESIGNER concept is shown by K-targeted subtraction of four bioactive prenylated phenols, isoxanthohumol (1), 8-prenylnaringenin (2), 6-prenylnaringenin (3), and xanthohumol (4), from a standardized hops (Humulus lupulus L.) extract using specific solvent systems. Conversely, adding K-targeted isolates allows enrichment of the original extract and hence provides an augmented DESIGNER material. Multiple countercurrent separation steps were used to purify each of the four compounds, and four DESIGNER extracts with varying depletions were prepared. The DESIGNER approach innovates the characterization of chemically complex extracts through integration of enabling technologies such as countercurrent separation, K-by-bioactivity, the residual complexity concepts, as well as quantitative analysis by (1)H NMR, LC-MS, and HiFSA-based NMR fingerprinting.

Qualitative and quantitative evaluation of solvent systems for countercurrent separation

Rational solvent system selection for countercurrent chromatography and centrifugal partition chromatography technology (collectively known as countercurrent separation) studies continues to be a scientific challenge as the fundamental questions of comparing polarity range and selectivity within a solvent system family and between putative orthogonal solvent systems remain unanswered. The current emphasis on metabolomic investigations and analysis of complex mixtures necessitates the use of successive orthogonal countercurrent separation (CS) steps as part of complex fractionation protocols. Addressing the broad range of metabolite polarities demands development of new CS solvent systems with appropriate composition, polarity (π), selectivity (σ), and suitability. In this study, a mixture of twenty commercially available natural products, called the GUESSmix, was utilized to evaluate both solvent system polarity and selectively characteristics. Comparisons of GUESSmix analyte partition coefficient (K) values give rise to a measure of solvent system polarity range called the GUESSmix polarity index (GUPI). Solvatochromic dye and electrical permittivity measurements were also evaluated in quantitatively assessing solvent system polarity. The relative selectivity of solvent systems were evaluated with the GUESSmix by calculating the pairwise resolution (αip), the number of analytes found in the sweet spot (Nsw), and the pairwise resolution of those sweet spot analytes (αsw). The combination of these parameters allowed for both intra- and inter-family comparison of solvent system selectivity. Finally, 2-dimensional reciprocal shifted symmetry plots (ReSS(2)) were created to visually compare both the polarities and selectivities of solvent system pairs. This study helps to pave the way to the development of new solvent systems that are amenable to successive orthogonal CS protocols employed in metabolomic studies.