Estrogenic flavonoids and their molecular mechanisms of action

Estrogenic actions of alkaloids: Structural characteristics and molecular mechanisms

This comprehensive review of estrogenic alkaloids reveals that although the number is small, they exhibit a wide range of structures, biosynthesis pathways, mechanisms of action, and applications. Estrogenic alkaloids belong to different classes, different biosynthetic pathways, different estrogenic actions (estrogenic/synergistic, anti-estrogenic/antagonistic, biphasic, and acting as a selective estrogen receptor modulator or SERM), different receptor-initiated signaling pathways, different ways of modulations of estrogen action, and different applications. The future applications of estrogenic alkaloids, such as those for diagnostics, drug development, and therapeutics, are considered with the help of new databases containing comprehensive descriptions of their relationships and more elaborate artificial intelligence-based prediction technologies. Structure-activity studies reveal the significance of the nitrogen atom for their structural and functional diversity, which may help support their broader applications. Based on the summary of previous reports, estrogenic alkaloids have significant potential for future applications.

In-silico study of novel dimeric flavonoid (OC251FR2) isolated from the seeds of Garcinia kola Heckel (Clusiaceae) against alpha estrogen receptor (ER-α) of breast cancer

Estrogen hormone dependence accounts for a major cause in the incidence of women breast cancer. ER-α is the major ER subtype in the mammary epithelium and plays a critical role in breast cancer progression. Tamoxifen (1-[4-(2-dimethylaminoethoxy)-phenyl]-1,2- diphenylbut-1(Z)-ene) is a nonsteroidal antiestrogen prodrug which formed pharmacologically active metabolite, 4-hydroxytamoxifen, largely used for endocrine therapy in pre and postmenopausal women with ER-positive breast cancer. However, long term treatment with tamoxifen results in acquires resistance and high probability of disease recurring, hence the need for an alternative breast cancer drug. In silico approach was used to investigate the inhibitory activities of a novel dimeric flavanonol OC251FR2 (3,3'-oxybis(5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one)-3,3'-oxybis(5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one) isolated from the chloroform fraction of Garcinia kola, against alpha Estrogen receptor (ER-α); a major contributor to the growth of breast cancer. The docking was conducted using Maestro module 13.5 to obtained the ER-α PDB (5W9C) from NCBI. The OC251FR2 was docked using ligprep module with 4-hydroxytamoxifen being the reference drug. The qikpro was used to investigate the drug-likeliness while ligand docking and induced fit docking were used to investigate the interaction and binding affinity of the ligands with the active sites of the PDB. The result shows that the isolated OC251FR2 with docking score value of -6.214 interact more with amino acids in the active sites via H-bond, pi-pi interaction than the reference drug 4-Hydroxytamoxifen with a docking score value of -5.289. The drug-likeliness determined by qikpro shows that OC251FR2 violated three of the Lipinski rules of 5, and also have percent oral absorption. The quantum mechanics values show that OC251FR2 have similar properties comparable to the reference drug 4-hydroxytamoxifen. Hence, can serve as potential lead against alpha Estrogen receptor (ER-α).

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00282-5.

Validating the nutraceutical and neuroprotective pharmacodynamics of flavones

Neurodegenerative disorders are generally characterized by progressive neuronal loss and cognitive decline, with underlying mechanisms involving oxidative stress, protein aggregation, neuroinflammation, and synaptic dysfunction. Currently, the available treatment options only improve the symptoms of the disease but do not stop disease progression; neurodegeneration. This underscores the urgent need for novel therapeutic strategies targeting multiple neurodegenerative pathways alongside the conventional therapeutic strategies available. Emerging evidence demonstrates that flavones a subgroup of flavonoids found abundantly in various dietary sources, have surfaced as promising candidates for neuroprotection due to their multifaceted pharmacological properties. Flavones possess the potency to modulate these pathophysiological processes through their antioxidant, anti-inflammatory, and neurotrophic activities. Additionally, flavones have been shown to interact with various cellular targets, including receptors and enzymes, to confer neuroprotection. Though there are ample evidence available, the nutraceutical and neuroprotective pharmacodynamics of flavones have not been very well established. Hence, the current review aims to explores the therapeutic potential of flavones as nutraceuticals with neuroprotective effects, focusing on their ability to modulate key pathways implicated in neurodegenerative diseases. The current article also aims to actuate supplementary research into flavones as potential agents for alleviating neurodegeneration and improving patient outcomes in neurodegenerative disorders globally.

Antimicrobial isoflavans and other metabolites of Dalea nana

The phytochemical investigation of extracts from Dalea nana roots and aerial parts led to the isolation of thirteen phenolic compounds. Three previously undescribed isoflavans, named verdeans A-C (1, 3, and 7), were characterized. Two additional isoflavans (2 and 5) were previously undescribed enantiomers of known compounds. A previously undescribed isoflavone (verdean D, 10) was found, and the known specialized metabolites, isoflavans 4, 6, 8, and 9, isoflavone 11, flavone 12, and a 2-arylbenzofuran 13, were also isolated. All but one (7) of the isoflavans were prenylated. The structures of the previously undescribed compounds were deduced by NMR spectroscopy, supported by HRESI mass spectrometry. The absolute configurations of 1-3, 5, and 7-9 were determined by ECD. Compounds 1, 3, 4, 6, and 8 exhibited in vitro antimicrobial activities, causing complete growth inhibition (MIC) at concentrations between 6.7 and 37.0 μM against Cryptococcus neoformans and between 8.9 and 25.0 μM against methicillin resistant Staphylococcus aureus (MRSA). The most broadly active previously undescribed compound was verdean A (1), with MIC values of 6.7 and 12.9 μM toward C. neoformans and MRSA, respectively, and an MIC of 10.0 μM against the often-intractable C. albicans.

The Antioxidant Activity of Atomized Extracts of the Leaves and Stems of Cnidoscolus diacanthus (Pax & K. Hoffm.) J.F. Macbr. from Peru and Their Effect on Sex Hormone Levels in Rats

In this research, we aimed to determine the antioxidant activity of an atomized extract of Cnidoscolus diacanthus (Pax & K. Hoffm.) J.F. Macbr., known in Peru as "huanarpo hembra", and its effect on sex hormone levels. Its phytochemical profile was determined using liquid chromatography-mass spectrometry (LC-MS), while its total phenol content (TPC) and total flavonoids (TFs) were determined using the Folin-Ciocalteu method and the aluminum chloride method. Its antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), the radical 2,2-azino-bis-3-ethylbenzthiazolin-6 sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP). The biological activity of C. diacanthus and its effect on sexual hormones were determined in Holtzman rats of both sexes. Phytochemical analysis revealed the presence of flavonoids and phenolic compounds in its leaves and stems, mainly rutin, quercetin, chlorogenic acid, and genistein. However, the stem extract contained higher total phenol (464.38 ± 4.40 GAE/g) and flavonoid (369.17 ± 3.16 mg QE/g of extract) contents than the leaf extract (212.38 ± 3.19 mg GAE/g and 121.49 ± 2.69 mg QE/g). For DPPH, ABTS, and FRAP, the Trolox-equivalent antioxidant capacity (TEAC) was 597.20 ± 5.40 µmol/g, 452.67 ± 5.76 µmol/g, and 535.91 ± 1.56 µmol/g, respectively, for the stems, while for the leaves, it was 462.39 ± 3.99 µmol/g, 202.32 ± 5.20 µmol/g, and 198.13 ± 1.44 µmol/g, respectively. In terms of the values for hormonal levels, at a dose of 100 mg/kg of the extract, testosterone levels of 1.430 ng/mL (with the leaf extract) and 1.433 ng/mL (with the stem extract), respectively, were found in the male rats. Regarding estradiol levels, in the female rats, these were 10.425 ng/mL (leaf extract) and 8.775 ng/mL (stem extract), while their levels of luteinizing hormone were 0.320 mIU/mL (leaf extract) and 0.273 mIU/mL (stem extract). For the follicle-stimulating hormone, levels of 0.858 mIU/mL (leaf extract) and 0.840 mIU/mL (stem extract) were found in the female rats, and levels of 0.220 mIU/mL (leaf extract) and 0.200 mIU/mL (stem extract) were found in the male rats. It is concluded that the C. diacanthus stem extract had a greater antioxidant capacity than the leaf extract, while both extracts had a superior effect on the sex hormone levels in the female rats compared to the male rats.

Chronic disease management via modulation of cellular signaling by phytoestrogen Bavachin

The emergence of chronic diseases, particularly cancers, cardiovascular, and bone disorders, presents a formidable challenge, as currently available synthetic drugs often result in significant side effects and incur higher costs. Phytoestrogen Bavachin, present in the Psoralea corylifolia L. plant, represents structural and functional similarity to mammalian estrogen and has recently attracted researchers for its medicinal properties. This review spotlighted the extraction methods, bioavailability and therapeutic interventions of Bavachin against diseases. Bavachin exerted estrogenic properties, demonstrating the ability to bind to estrogen receptors (ERs), mimicking the actions of human estrogen and initiating estrogen-responsive pathways. Bavachin delivered potent therapeutic ventures in abrogating chronic diseases, including cancer, neuronal, bone, cardiovascular, skin, lung, and liver disorders via targeting signaling transductions, managing calcium signaling, immune regulation, inflammation, apoptosis, and oxidative stress. In-silico analysis, including Gene ontology and pathway enrichment analysis, retrieved molecular targets of Bavachin, majorly cytochrome c oxidase (COX), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3), and ER, hypothesizing Bavachin's cellular mechanism in preventing crucial health ailments. Limitations of Bavachin were also summarized, evidenced by hepatotoxicity at specific dosage levels. In conclusion, Bavachin showed promising therapeutic efficacy in suppressing chronic diseases and can be considered as an adequate replacement for hormone replacement therapy, necessitating further investigations on its effectiveness, safety, and clinical outcomes.

The associations between dietary flavonoids intake and risk of depressive symptom in diabetic patients: Data from NHANES 2007-2008, 2009-2010, and 2017-2018

BACKGROUND

The increasing incidence of depressive symptoms in diabetic patients contributes to the global burden of disease, but few epidemiological studies have evaluated the relationship between dietary flavonoids intake and depressive symptoms in diabetic patients in American adults.

OBJECTIVE

This study intended to evaluate the associations of dietary flavonoids intake and depressive symptoms in diabetic patients in American adults.

METHODS

We conducted a cross-sectional analysis of 1993 adults aged ≥20 years old who participated in the 2007-2008, 2009-2010, and 2017-2018 National Health and Nutrition Examination Surveys (NHANES). Chi-square test and independent-sample t-test were used to compare subjects' characteristics. Logistic regression model was further used to analyze the relationship between dietary flavonoid intake and depressive symptoms in diabetic patients. Restricted cubic spline (RCS) analysis was used to investigate the non-linear relationship between dietary flavonoid intake and the prevalence of depressive symptoms in diabetic patients. The weighted quartile sum (WQS) regression was used to analyze the effect of 29 flavonoids monomers.

RESULTS

The results showed that the total flavonoid intake in the third quartile (OR, 0.635; 95 % CI,0.419-0.962; P, 0.032) was significantly associated with a reduced risk of depressive symptoms in diabetic patients compared with the lowest quartile. And there was a U-shaped association between dietary flavonoid intake and risk of depressive symptoms in diabetic patients. Top contributors of flavonoid monomers were eriodictyol, naringenin, and theaflavin-3'-gallate, accounting for a percentage of 30.83 %, 22.17 %, and 6.92 %, respectively.

CONCLUSION

Moderate (56.07-207.12 mg/day) dietary flavonoid intake was associated with a reduced risk of depressive symptoms in diabetic patients. The important flavonoid monomers were eriodictyol, naringenin, and theaflavin-3'-gallate.

Antidepressant- and Anxiolytic-like Effects of Pomegranate: Is It Acting by Common or Well-Known Mechanisms of Action?

The pharmacological effects of pomegranates have been described considering metabolic aspects such as hypoglycemic and hypolipidemic activities. The pomegranate extract has activity on the central nervous system (CNS) as a natural antidepressant and anxiolytic. The chemical composition of pomegranates is complex since the bioactive compounds are multiple secondary metabolites that have been identified in the extracts derived from the peel, seed, flowers, leaves, or in their combination; so, it has not been easy to identify an individual compound as responsible for its observed pharmacological properties. From this point of view, the present review analyzes the effects of crude extracts or fractions of pomegranates and their possible mechanisms of action concerning antidepressant- and anxiolytic-like effects in animal models. Serotonin receptors, estrogen receptors, the peroxisome proliferator-activated receptor gamma (PPARγ), or monoamine oxidase enzymes, as well as potent antioxidant and neuroplasticity properties, have been described as possible mediators involved in the antidepressant- and anxiolytic-like behaviors after pomegranate treatment. The pharmacological effects observed on the CNS in experimental models associated with a specific stress level suggest that pomegranates could simultaneously modulate the stress response by activating several targets. For the present review, scientific evidence was gathered to integrate it and suggest a possible pathway for mediators to be involved in the mechanisms of action of the pomegranate's antidepressant- and anxiolytic-like effects. Furthermore, the potential benefits are discussed on comorbid conditions with anxiety and depression, such as perimenopause transition and pain.

Bioisosteric heterocyclic analogues of natural bioactive flavonoids by scaffold-hopping approaches: State-of-the-art and perspectives in medicinal chemistry

The flavonoid family is a set of well-known bioactive natural molecules, with a wide range of potential therapeutic applications. Despite the promising results obtained in preliminary in vitro/vivo studies, their pharmacokinetic and pharmacodynamic profiles are severely compromised by chemical instability. To address this issue, the scaffold-hopping approach is a promising strategy for the structural optimization of natural leads to discover more potent analogues. In this scenario, this Perspective provides a critical analysis on how the replacement of the chromon-4-one flavonoid core with other bioisosteric nitrogen/sulphur heterocycles might affect the chemical, pharmaceutical and biological properties of the resulting new chemical entities. The investigated derivatives were classified on the basis of their biological activity and potential therapeutic indications. For each session, the target(s), the specific mechanism of action, if available, and the key pharmacophoric moieties were highlighted, as revealed by X-ray crystal structures and in silico structure-based studies. Biological activity data, in vitro/vivo studies, were examined: a particular focus was given on the improvements observed with the new heterocyclic analogues compared to the natural flavonoids. This overview of the scaffold-hopping advantages in flavonoid compounds is of great interest to the medicinal chemistry community to better exploit the vast potential of these natural molecules and to identify new bioactive molecules.

Qixian granule inhibits ferroptosis in vascular endothelial cells by modulating TRPML1 in the lysosome to prevent postmenopausal atherosclerosis

ETHNOPHARMACOLOGICAL RELEVANCE

QiXian Granule (QXG) is an integrated traditional Chinese medicine formula used to treat postmenopausal atherosclerotic (AS) cardiovascular diseases. The previous studies have found that QXG inhibited isoproterenol (ISO)-induced myocardial remodeling. And its active ingredient, Icraiin, can inhibit ferroptosis by promoting oxidized low-density lipoprotein (xo-LDL)-induced vascular endothelial cell injury and autophagy in atherosclerotic mice. Another active ingredient, Salvianolic Acid B, can suppress ferroptosis and apoptosis during myocardial ischemia/reperfusion injury by reducing ubiquitin-proteasome degradation of Glutathione Peroxidase 4 (GPX4) and down-regulating the reactive oxygen species (ROS)- c-Jun N-terminal kinases (JNK)/mitogen-activated protein kinase (MAPK) pathway.

AIM OF THE STUDY

The objective of this research was to assess the possible impact of QXG on atherosclerosis in postmenopausal individuals and investigate its underlying mechanisms.

MATERIALS AND METHODS

Female ApoE-/- mice underwent ovariectomy and were subjected to a high-fat diet (HFD) to establish a postmenopausal atherosclerosis model. The therapeutic effects of QXG were observed in vivo and in vitro through intraperitoneal injection of erastin, G-protein Coupled Estrogen Receptor (GPER) inhibitor (G15), and silent Mucolipin Transient Receptor Potential Channel 1 (TRPML1) adenovirus injection via tail vein. UPLC-MS and molecular docking techniques identified and evaluated major QXG components, contributing to the investigation of QXG's anti-postmenopausal atherosclerotic effects.

RESULTS

QXG increased serum Estradiol levels, decreased follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, which indicated QXG had estrogen-like effects in Ovx/ApoE-/- mice. Furthermore, QXG demonstrated the potential to impede the progression of AS in Ovx/ApoE-/- mice, as evidenced by reductions in serum triglycerides (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) levels. Additionally, QXG inhibited ferroptosis in Ovx/ApoE-/- mice. Notably, UPLC-MS analysis identified a total of 106 active components in QXG. The results of molecular docking analysis demonstrated that Epmedin B, Astragaloside II, and Orientin exhibit strong binding affinity towards TRPML1. QXG alleviates the progression of atherosclerosis by activating TRPML1 through the GPER pathway or directly activating TRPML1, thereby inhibiting GPX4 and ferritin heavy chain (FTH1)-mediated iron pendant disease. In vitro, QXG-treated serum suppressed proliferation, migration, and ox-LDL-induced MMP and ROS elevation in HAECs.

CONCLUSION

QXG inhibited GPX4 and FTH1-mediated ferroptosis in vascular endothelial cells through up-regulating GPER/TRPML1 signaling, providing a potential therapeutic option for postmenopausal females seeking a safe and effective medication to prevent atherosclerosis. The study highlights QXG's estrogenic properties and its promising role in combating postmenopausal atherosclerosis.

Autoclaving-treated germinated brown rice relieves hyperlipidemia by modulating gut microbiota in humans

Introduction

Germinated brown rice is a functional food with a promising potential for alleviating metabolic diseases. This study aimed to explore the hypolipidemic effects of autoclaving-treated germinated brown rice (AGBR) and the underlying mechanisms involving gut microbiota.

Methods

Dietary intervention with AGBR or polished rice (PR) was implemented in patients with hyperlipidemia for 3 months, and blood lipids were analyzed. Nutritional characteristics of AGBR and PR were measured and compared. Additionally, 16S rDNA sequencing was performed to reveal the differences in gut microbiota between the AGBR and PR groups.

Results

AGBR relieves hyperlipidemia in patients, as evidenced by reduced levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein-B, and elevated levels of high-density lipoprotein cholesterol and apolipoprotein-A1. In terms of nutrition, AGBR had significantly higher concentrations of free amino acids (10/16 species), γ-aminobutyric acid, resistant starch, soluble dietary fiber, and flavonoids (11/13 species) than PR. In addition, higher microbial abundance, diversity, and uniformity were observed in the AGBR group than in the PR group. At the phylum level, AGBR reduced Firmicutes, Proteobacteria, Desulfobacterota, and Synergistota, and elevated Bacteroidota and Verrucomicrobiota. At the genus level, AGBR elevated Bacteroides, Faecalibacterium, Dialister, Prevotella, and Bifidobacterium, and reduced Escherichia-Shigella, Blautia, Romboutsia, and Turicibacter.

Discussion

AGBR contributes to the remission of hyperlipidemia by modulating the gut microbiota.

Characterization of flavonoids with potent and subtype-selective actions on estrogen receptors alpha and beta

The initial step in estrogen-regulated transcription is the binding of a ligand to its cognate receptors, named estrogen receptors (ERα and ERβ). Phytochemicals present in foods and environment can compete with endogenous hormones to alter physiological responses. We screened 224 flavonoids in our engineered biosensor ERα and ERβ PRL-array cell lines to characterize their activity on several steps of the estrogen signaling pathway. We identified 83 and 96 flavonoids that can activate ERα or ERβ, respectively. While most act on both receptors, many appear to be subtype-selective, including potent flavonoids that activate ER at sub-micromolar concentrations. We employed an orthogonal assay using a transgenic zebrafish in vivo model that validated the estrogenic potential of these compounds. To our knowledge, this is the largest study thus far on flavonoids and the ER pathway, facilitating the identification of a new set of potential endocrine disruptors acting on both ERα and ERβ.

Bavachin Rejuvenates Sensitivity of Colistin against Colistin-Resistant Gram-Negative Bacteria

The emergence of plasmid-mediated colistin resistance threatens the efficacy of colistin as a last-resort antibiotic used to treat infection caused by Gram-negative bacteria (GNB). Given the shortage of new antibiotics, the discovery of adjuvants to existing antibiotics is a promising strategy to combat infections caused by multidrug-resistant (MDR) GNB. This study was designed to investigate the potential synergistic antibacterial activity of bavachin, a bioactive compound extracted from the Psoralea Fructus, combined with colistin against MDR GNB. Herein, the synergistic efficacy in vitro and the therapeutic efficacy of colistin combined with bavachin in vivo were evaluated. The synergistic mechanism was detected by fluorescent probe and the transcript levels of mcr-1. Bavachin combined with colistin showed an excellent synergistic activity against GNB, as the FICI ≤ 0.5. In contrast to colistin alone, combination therapy dramatically increased the survival rate of Galleria mellonella and mice in vivo. Moreover, the combination of bavachin and colistin significantly reduced the amount of bacterial biofilm formation, improved the membrane disruption of colistin and inhibited mcr-1 transcription. These findings show that bavachin is a potential adjuvant of colistin, which may provide a new strategy to combat colistin-resistant bacteria infection with lower doses of colistin.

Estrogenic Prenylated Flavonoids in Sophora flavescens

Sophora flavescens is a medicinal herb distributed widely in Japan and it has been used to treat various diseases and symptoms. To explore its pharmacological use, we examined the estrogenic activity of four prenylated flavonoids, namely kurarinone, kushenols A and I, and sophoraflavanone G, which are characterized by the lavandulyl group at position 8 of ring A, but have variations in the hydroxyl group at positions 3 (ring C), 5 (ring A) and 4' (ring B). These prenylated flavonoids were examined via cell proliferation assays using sulforhodamine B, Western blotting, and RT-PCR, corresponding to cell, protein, and transcription assays, respectively, based on estrogen action mechanisms. All the assays employed here found weak but clear estrogenic activities for the prenylated flavonoids examined. Furthermore, the activities were inhibited by an estrogen receptor antagonist, suggesting that the activities were likely being mediated by the estrogen receptors. However, there were differences in the activity, attributable to the hydroxyl group at position 4', which is absent in kushenol A. While the estrogenic activity of kurarinone and sophoraflavanone G has been reported before, to the best of our knowledge, there are no such reports on kushenols A and I. Therefore, this study represents the first report of their estrogenic activity.

Interaction between dietary flavonoid intake and trouble sleeping on non-alcoholic fatty liver disease risk: a cross-sectional study

OBJECTIVE

The possible interaction of dietary flavonoid intake and sleep on non-alcoholic fatty liver disease (NAFLD) has not been well studied. This study investigated the interaction between dietary flavonoid intake and trouble sleeping on the risk of NAFLD.

METHODS

Three discrete National Health and Nutrition Examination Survey data cycles from 2007 to 2010 and 2017 to 2018 were used. NAFLD was diagnosed by a US Fatty Liver Index ≥30. A sleep questionnaire diagnosed trouble sleeping. Univariate and multivariate logistic regression, restricted cubic spline (RCS) and subgroup analyses were used to evaluate the association between dietary flavonoids, trouble sleeping and NAFLD. We employed the relative excess risk due to interaction, attributable proportion of interaction and synergy index to evaluate additive interactions.

RESULTS

Ultimately, 5056 participants were enrolled, and higher anthocyanidins and flavanones intake was negatively correlated with NAFLD. Conversely, trouble sleeping was positively associated with NAFLD. These correlations remained stable after adjusting for confounders, and there was a sex difference in this relationship. In the RCS model, anthocyanins were negatively non-linearly related to NAFLD, while flavanones showed a negative linear relationship. Moreover, there was a synergistic interplay between low dietary anthocyanin intake and trouble sleeping on the risk of NAFLD. A similar relationship existed for flavanone intake.

CONCLUSION

Anthocyanin and flavanone intake were negatively associated, whereas trouble sleeping was positively associated with NAFLD risk. There was a synergistic effect of low anthocyanin intake and trouble sleeping. The same relationship existed for low flavanone intake.

Antifungal and Antiproliferative Activity of Pistagremic Acid and Flavonoids Extracted from the Galls of Pistacia chinensis subsp. integerrima

Pistacia chinensis subsp. integerrima (J.L. Stewart) Rech. f. is a plant known for its therapeutic applications in traditional medicine, which are related to its antimicrobial, anticancer, antioxidant, anti-inflammatory, analgesic, antidiarrheal, and muscle relaxant properties. The galls of P. chinensis are rich in triterpenes and flavonoids, and we here report the extraction of pistagremic acid (1), apigenin (2) and sakuranetin (3) from this source. The isolated compounds were tested against Aspergillus flavus, Candida albicans, Candida glabrata, Fusarium solani, Microsporum canis and Trichoderma longibrachiatum. The results highlighted the antimicrobial activity of flavonoids 2 and 3, suggesting that this class of molecules may be responsible for the effect related to the traditional use. On the other hand, when the compounds and the extract were tested for their antiproliferative activity on a panel of 4 human cancer cell lines, the triterpene pistagremic acid (1) showed a higher potential, thus demonstrating a different bioactivity profile. Structure-based docking and molecular dynamics simulations were used to help the interpretation of experimental results. Taken together, the here reported findings pave the way for the rationalization of the use of P. chinensis extracts, highlighting the contributions of the different components of galls to the observed bioactivity.

Polymethoxylated flavonoids in citrus fruits: absorption, metabolism, and anticancer mechanisms against breast cancer

Polymethoxylated flavonoids (PMFs) are a subclass of flavonoids found in citrus fruits that have shown multifunctional biological activities and potential anticancer effects against breast cancer. We studied the absorption, metabolism, species source, toxicity, anti-cancer mechanisms, and molecular targets of PMFs to better utilize their anticancer activity against breast cancer. We discuss the absorption and metabolism of PMFs in the body, including the methylation, demethylation, and hydroxylation processes. The anticancer mechanisms of PMFs against breast cancer were also reviewed, including the estrogen activity, cytochrome P-450 enzyme system, and arylhydrocarbon receptor (AhR) inhibition, along with various molecular targets and potential anticancer effects. Although PMFs may be advantageous in the prevention and treatment for breast cancer, there is a lack of clinical evidence and data to support their efficacy. Despite their promise, there is still a long way to go before PMFs can be applied clinically.

Isolation of Pro-Osteogenic Compounds from Euptelea polyandra That Reciprocally Regulate Osteoblast and Osteoclast Differentiation

Plants contain a large number of small-molecule compounds that are useful for targeting human health and in drug discovery. Healthy bone metabolism depends on the balance between bone-forming osteoblast activity and bone-resorbing osteoclast activity. In an ongoing study searching for 22 plant extracts effective against osteoporosis, we found that the crude extract of Euptelea polyandra Sieb. et Zucc (E. polyandra) had osteogenic bioactivity. In this study, we isolated two compounds, isoquercitrin (1) and astragalin (2), responsible for osteogenic bioactivity in osteoblastic MC3T3-E1 cells from the leaf of E. polyandra using column chromatography and the spectroscopic technique. This is the first report to isolate astragalin from E. polyandra. Compounds (1) and (2) promoted osteoblast differentiation by increasing alkaline phosphatase (ALP) activity and alizarin red S stain-positive calcium deposition, while simultaneously suppressing tartrate-resistant acid phosphatase (TRAP)-positive osteoclast differentiation in RAW264.7 cells at non-cytotoxic concentrations. Isoquercitrin (1) and astragalin (2) increased the expression of osteoblastic differentiation genes, Osterix, ALP, and Osteoprotegerin in the MC3T3-E1 cells, while suppressing osteoclast differentiation genes, TRAP, Cathepsin K, and MMP 9 in the RAW264.7 cells. These compounds may be ideal targets for the treatment of osteoporosis due to their dual function of promoting bone formation and inhibiting bone resorption.

Recent advances in anti-inflammatory active components and action mechanisms of natural medicines

Inflammation is a series of reactions caused by the body's resistance to external biological stimuli. Inflammation affects the occurrence and development of many diseases. Anti-inflammatory drugs have been used widely to treat inflammatory diseases, but long-term use can cause toxic side-effects and affect human functions. As immunomodulators with long-term conditioning effects and no drug residues, natural products are being investigated increasingly for the treatment of inflammatory diseases. In this review, we focus on the inflammatory process and cellular mechanisms in the development of diseases such as inflammatory bowel disease, atherosclerosis, and coronavirus disease-2019. Also, we focus on three signaling pathways (Nuclear factor-kappa B, p38 mitogen-activated protein kinase, Janus kinase/signal transducer and activator of transcription-3) to explain the anti-inflammatory effect of natural products. In addition, we also classified common natural products based on secondary metabolites and explained the association between current bidirectional prediction progress of natural product targets and inflammatory diseases.

Mitochondria-Targeted Lipid Nanoparticles Loaded with Rotenone as a New Approach for the Treatment of Oncological Diseases

This research is based on the concept that mitochondria are a promising target for anticancer therapy, including thatassociated with the use of oxidative phosphorylation blockers (mitochondrial poisons). Liposomes based on L-α-phosphatidylcholine (PC) and cholesterol (Chol) modified with cationic surfactants with triphenylphosphonium (TPPB-n, where n = 10, 12, 14, and 16) and imidazolium (IA-n(OH), where n = 10, 12, 14, and 16) head groups were obtained. The physicochemical characteristics of liposomes at different surfactant/lipid molar ratios were determined by dynamic/electrophoretic light scattering, transmission electron microscopy, and spectrophotometry. The hydrodynamic diameter of all the systems was within 120 nm with a polydispersity index of no more than 0.24 even after 2 months of storage. It was shown that cationization of liposomes leads to an increase in the internalization of nanocontainers in pancreatic carcinoma (PANC-1) and duodenal adenocarcinoma (HuTu 80) cells compared with unmodified liposomes. Also, using confocal microscopy, it was shown that liposomes modified with TPPB-14 and IA-14(OH) statistically better colocalize with the mitochondria of tumor cells compared with unmodified ones. At the next stage, the mitochondrial poison rotenone (ROT) was loaded into cationic liposomes. It was shown that the optimal loading concentration of ROT is 0.1 mg/mL. The Korsmeyer-Peppas and Higuchi kinetic models were used to describe the release mechanism of ROT from liposomes in vitro. A significant reduction in the IC50 value for the modified liposomes compared with free ROT was shown and, importantly, a higher degree of selectivity for the HuTu 80 cell line compared with the normal cells (SI value is 307 and 113 for PC/Chol/TPPB-14/ROT and PC/Chol/IA-14(OH)/ROT, respectively) occurred. It was shown that the treatment of HuTu 80 cells with ROT-loaded cationic liposomal formulations leads to a dose-dependent decrease in the mitochondrial membrane potential.

Insight into the Potential Mechanisms of Endocrine Disruption by Dietary Phytoestrogens in the Context of the Etiopathogenesis of Endometriosis

Phytoestrogens (PEs) are estrogen-like nonsteroidal compounds derived from plants (e.g., nuts, seeds, fruits, and vegetables) and fungi that are structurally similar to 17β-estradiol. PEs bind to all types of estrogen receptors, including ERα and ERβ receptors, nuclear receptors, and a membrane-bound estrogen receptor known as the G protein-coupled estrogen receptor (GPER). As endocrine-disrupting chemicals (EDCs) with pro- or antiestrogenic properties, PEs can potentially disrupt the hormonal regulation of homeostasis, resulting in developmental and reproductive abnormalities. However, a lack of PEs in the diet does not result in the development of deficiency symptoms. To properly assess the benefits and risks associated with the use of a PE-rich diet, it is necessary to distinguish between endocrine disruption (endocrine-mediated adverse effects) and nonspecific effects on the endocrine system. Endometriosis is an estrogen-dependent disease of unknown etiopathogenesis, in which tissue similar to the lining of the uterus (the endometrium) grows outside of the uterus with subsequent complications being manifested as a result of local inflammatory reactions. Endometriosis affects 10-15% of women of reproductive age and is associated with chronic pelvic pain, dysmenorrhea, dyspareunia, and infertility. In this review, the endocrine-disruptive actions of PEs are reviewed in the context of endometriosis to determine whether a PE-rich diet has a positive or negative effect on the risk and course of endometriosis.

Alpinumisoflavone Activates Disruption of Calcium Homeostasis, Mitochondria and Autophagosome to Suppress Development of Endometriosis

Alpinumisoflavone is an isoflavonoid extracted from the Cudrania tricuspidate fruit and Genista pichisermolliana. It has various physiological functions, such as anti-inflammation, anti-proliferation, and apoptosis, in malignant tumors. However, the effect of alpinumisoflavone is still not known in chronic diseases and other benign reproductive diseases, such as endometriosis. In this study, we examined the cell death effects of alpinumisoflavone on the endometriosis cell lines, End1/E6E7 and VK2/E6E7. Results indicated that alpinumisoflavone inhibited cell migration and proliferation and led to cell cycle arrest, depolarization of mitochondria membrane potential, apoptosis, and disruption of calcium homeostasis in the endometriosis cell lines. However, the cellular proliferation of normal uterine epithelial cells was not changed by alpinumisoflavone. The alteration in Ca²⁺ levels was estimated in fluo-4 AM-stained End1/E6E7 and VK2/E6E7 cells after alpinumisoflavone treatment with or without calcium inhibitor, 2-aminoethoxydiphenyl borate (2-APB). The results indicated that a combination of alpinumisoflavone and a calcium inhibitor reduced the calcium accumulation in the cytosol of endometriosis cells. Additionally, alpinumisoflavone decreased oxidative phosphorylation (OXPHOS) in the endometriotic cells. Moreover, protein expression analysis revealed that alpinumisoflavone inactivated AKT signaling pathways, whereas it increased MAPK, ER stress, and autophagy regulatory proteins in End1/E6E7 and VK2/E6E7 cell lines. In summary, our results suggested that alpinumisoflavone could be a promising effective management agent or an adjuvant therapy for benign disease endometriosis.

Microbial Metabolism of the Soy Isoflavones Daidzein and Genistein in Postmenopausal Women: Human Intervention Study Reveals New Metabotypes

BACKGROUND

Soy isoflavones belong to the group of phytoestrogens and are associated with beneficial health effects but are also discussed to have adverse effects. Isoflavones are intensively metabolized by the gut microbiota leading to metabolites with altered estrogenic potency. The population is classified into different isoflavone metabotypes based on individual metabolite profiles. So far, this classification was based on the capacity to metabolize daidzein and did not reflect genistein metabolism. We investigated the microbial metabolite profile of isoflavones considering daidzein and genistein.

METHODS

Isoflavones and metabolites were quantified in the urine of postmenopausal women receiving a soy isoflavone extract for 12 weeks. Based on these data, women were clustered in different isoflavone metabotypes. Further, the estrogenic potency of these metabotypes was estimated.

RESULTS

Based on the excreted urinary amounts of isoflavones and metabolites, the metabolite profiles could be calculated, resulting in 5 metabotypes applying a hierarchical cluster analysis. The metabotypes differed in part strongly regarding their metabolite profile and their estimated estrogenic potency.