Dietary polyacetylenes of the falcarinol type are inhibitors of breast cancer resistance protein (BCRP/ABCG2)

Phytochemical intervention in BCRP-driven cancer drug resistance: A comprehensive review

Drug resistance (DR) remains a significant challenge in cancer treatment, accounting for over 90 % of cancer-related deaths. Multidrug resistance (MDR) complicates chemotherapy by enabling cancer cells to evade therapeutic agents. This review focuses on the role of ATP-binding cassette (ABC) transporters, particularly the breast cancer resistance protein (BCRP), in mediating drug resistance. BCRP functions as a drug efflux pump, actively transporting chemotherapeutic agents out of cancer cells, thereby reducing their efficacy. The regulation of BCRP is influenced by various signaling pathways, including PI3K/AKT, MAPK/ERK, NF-κB, and Wnt/β-catenin, all of which collectively enhance its expression and contribute to the MDR phenotype. Recent studies have highlighted the potential of phytochemical-based strategies to reverse drug resistance by inhibiting these transporters. Compounds such as tetrandrine and resveratrol have shown promise in sensitizing drug-resistant cancer cells. Understanding the complex interplay between BCRP regulation and these signaling pathways is essential for the development of effective therapeutic strategies to counteract cancer. Targeting multiple pathways or employing combination therapies may offer new avenues to overcome MDR and improve treatment outcomes for cancer patients.

Antiparasitic activity of Eryngium bourgatii Gouan: Fractionation and isolation of constituents from roots and aerial parts

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants are rich in bioactive compounds with diverse properties that can preserve human health. Eryngium bourgatii is used in traditional medicine to purify the blood. Species of this genus have been used for their antibacterial, antitumor, antifungal or antiparasitic properties among others.

AIM OF THE STUDY

In this work, the antiparasitic properties against Leishmania donovani, Trypanosoma cruzi, and Plasmodium falciparum were evaluated.

MATERIALS AND METHODS

Methyl tert-butyl ether (MTBE), dichloromethane (DCM), and ethyl acetate (EtOAc) extracts of the roots and the non-flowering aerial parts were obtained by maceration at room temperature. Some of them were partitioned with solvents of increasing polarity, specifically n-hexane (n-Hex), dichloromethane (DCM), and ethyl acetate (EA) to isolate different fractions. Growth inhibition assays were performed against the three protozoa (L. donovani, T. cruzi, and P. falciparum). The active fractions were subsequently separated by chromatography to determine the secondary metabolites responsible for the activity. In addition, GC-MS studies were performed to further analyse the composition of the extracts and fractions.

RESULTS

Regarding the roots, the MTBE extract was the most potent leishmanicidal (77.7 % inhibition at 10 μg/mL). The activity increased in its n-Hex fraction (95.3 % inhibition), and in the DCM fraction, both leishmanicidal (93.6 %) and anti-Chagas activity (92.2 %) improved. Furanone 12, a new natural compound, was the main component of the extract and the most potent leishmanicide (96.7 %), sixteen times less than the reference drug, Amphotericin B. 11-Acetoxyfalcarindiol (19) was the most potent anti-Chagas (89.1 % inhibition). Regarding the aerial parts, the DCM extract was the most potent leishmanicide (83.3 %), which improved in its DCM fraction (95.7 %), mainly attributed to compound 12. The DCM fraction of the MTBE extract produced the best antichagasic result (93.3 % inhibition), attributed to falcarindiol (17). Practically, the same compounds were identified in the roots as in the aerial parts, but in different proportions. Nine pure compounds were isolated; 34 were identified in roots and 37 in the aerial parts by GC-MS, with alkyne compounds leading, followed by sesquiterpenes and fatty acids.

Disafynol: A polyacetylene dimer from Centaurea schmidii enhancing breast cancer cell apoptosis via oxidative and ER stress pathways

Phytochemical analysis of the aerial parts of Centaurea schmidii Wagenitz (Asteraceae) led to the isolation of disafynol, a novel polyacetylene, for the first time. This study investigated its anti-cancer effects and the mechanisms underlying these effects in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive) breast cancer cell lines. The cytotoxic effects of disafynol were evaluated using various concentrations to measure cell viability, apoptosis, reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), caspases-12/6 activity, and protein aggregation. Expression of apoptotic markers and endoplasmic reticulum (ER) stress-related genes was analyzed by western blot and reverse transcription-PCR analyses, respectively. Disafynol exhibited dose-dependent cytotoxicity, with greater potency in MDA-MB-231 cells (IC50: 10.6 µM) compared to MCF-7 cells (IC50: 30 µM), indicating hormone receptor-independent manner of cell growth inhibition. Treating cells with disafynol caused significant apoptosis, marked by enhanced ROS production and reduced MMP. Meanwhile, disafynol induced Bcl-2 downregulation, Bax upregulation, and caspase-12/6 activities in both breast cancer cells. Additionally, disafynol triggered ER stress, as evidenced by protein aggregation and upregulation of genes related to ER stress, including BIP, ATF4, CHOP, and XBP-1. Overall, disafynol demonstrates significant pro-apoptotic effects on breast cancer cells by inducing oxidative stress and activating the ER stress pathway. Its hormone receptor-independent cytotoxicity suggests potential therapeutic applications for treating breast cancers, including triple-negative subtypes.

ABCG2 Transports the Flukicide Nitroxynil and Affects Its Biodistribution and Secretion into Milk

The ABCG2 transporter plays a key role in pharmacological and toxicological processes, affecting bioavailability, tissue accumulation and milk secretion of its substrates. This protein is expressed in several biological barriers acting as a protective mechanism against xenobiotic exposure by pumping out a broad range of compounds. However, its induced expression during lactation in alveolar cells of mammary gland represents a relevant route for active transport of unwanted chemicals into milk. This work aimed to characterize the involvement of ABCG2 in systemic exposure and milk secretion of the flukicide nitroxynil. Using MDCK-II cells overexpressing the transporter, we showed that nitroxynil is an in vitro substrate of different species variants of ABCG2. Moreover, using wild-type and Abcg2-/- mice, we showed that murine Abcg2 clearly affects plasma levels of nitroxynil. We also reported differences in nitroxynil accumulation in several tissues, with almost 2-fold higher concentration in kidney, small intestine and testis of Abcg2-/- mice. Finally, we proved that nitroxynil secretion into milk was also affected by Abcg2, with a 1.9-fold higher milk concentration in wild-type compared with Abcg2-/- mice. We conclude that ABCG2 significantly impacts nitroxynil biodistribution by regulating its passage across biological barriers.

Role of N6-methyladenosine methylation in glioma: recent insights and future directions

Glioma is the most pervasive intracranial tumor in the central nervous system (CNS), with glioblastoma (GBM) being the most malignant type having a highly heterogeneous cancer cell population. There is a significantly high mortality rate in GBM patients. Molecular biomarkers related to GBM malignancy may have prognostic values in predicting survival outcomes and therapeutic responses, especially in patients with high-grade gliomas. In particular, N6-methyladenine (m6A) mRNA modification is the most abundant form of post-transcriptional RNA modification in mammals and is involved in regulating mRNA translation and degradation. Cumulative findings indicate that m6A methylation plays a crucial part in neurogenesis and glioma pathogenesis. In this review, we summarize recent advances regarding the functional significance of m6A modification and its regulatory factors in glioma occurrence and progression. Significant advancement of m6A methylation-associated regulators as potential therapeutic targets is also discussed.

Chemical Composition, Functional and Anticancer Properties of Carrot

Plants are a valuable source of drugs for cancer treatment. Daucus carota has been investigated for its health properties. In particular, Daucus carota L. subsp. Sativus, the common edible carrot root, has been found to be rich in bioactive compounds such as carotenoids and dietary fiber and contains many other functional components with significant health-promoting features, while Daucus carota L. subsp. Carrot (Apiacae), also known as wild carrot, has been usually used for gastric ulcer therapy, diabetes, and muscle pain in Lebanon. Here, we review the chemical composition of Daucus carota L. and the functional properties of both edible and wild carrot subspecies. Then, we focus on compounds with anticancer characteristics identified in both Daucus carota subspecies, and we discuss their potential use in the development of novel anticancer therapeutic strategies.

Essential Oils of Ferulago glareosa Kandemir&Hedge Roots and Aerial Parts: PCA and HCA Analyses

Ferulago glareosa Kandemir & Hedge. is an endemic species of the family Apiaceae for Turkey and has interesting morphological characteristics compared to the other members of the genus Ferulago Koch. In this study we investigated the essential oil compositions of the roots and aerial parts of F. glareosa for the first time and compared them with essential oil compositions of the roots and aerial parts of other species of the genus. In our study, major components of the essential oil of the roots were determined to be 2,3,6-trimethylbenzaldehyde (32.2 %), falcarinol (23.7 %), hexadecanoic acid (9.5 %) and 2,5-dimethoxy-p-cymene (5.9 %); and major components of the essential oil of the aerial parts were found to be α-pinene (33.7 %), p-cymene (14.8 %), γ-terpinene (13.2 %), (Z)-β-ocimene (12.4 %) and terpinolene (8.2 %). The essential oil compositions of F. glareosa root compare with essential oils components in the literature differ varies greatly. Hierarchical Cluster Analysis (HCA) was performed with Minitab software, utilizing 8 major components in the published 20 literatures, as well as in this study. Principal Component Analyses (PCA) were used in order to demonstrate chemotaxonomical variations in the composition of the essential oils of Ferulago species.

Pathways Affected by Falcarinol-Type Polyacetylenes and Implications for Their Anti-Inflammatory Function and Potential in Cancer Chemoprevention

Polyacetylene phytochemicals are emerging as potentially responsible for the chemoprotective effects of consuming apiaceous vegetables. There is some evidence suggesting that polyacetylenes (PAs) impact carcinogenesis by influencing a wide variety of signalling pathways, which are important in regulating inflammation, apoptosis, cell cycle regulation, etc. Studies have shown a correlation between human dietary intake of PA-rich vegetables with a reduced risk of inflammation and cancer. PA supplementation can influence cell growth, gene expression and immunological responses, and has been shown to reduce the tumour number in rat and mouse models. Cancer chemoprevention by dietary PAs involves several mechanisms, including effects on inflammatory cytokines, the NF-κB pathway, antioxidant response elements, unfolded protein response (UPR) pathway, growth factor signalling, cell cycle progression and apoptosis. This review summarises the published research on falcarinol-type PA compounds and their mechanisms of action regarding cancer chemoprevention and also identifies some gaps in our current understanding of the health benefits of these PAs.

Effects of Structural Variations on Antibacterial Properties for Conjugated Diynes Generated through Glaser Hay Couplings

Antibiotic resistance is a growing problem facing global societies today. Many new antibiotics are derivatized versions of already existing antibiotics, which allows for antibiotic resistance to arise. To combat this issue, new antibiotics with different core structures need to be elucidated. Asymmetrical polyacetylenes have been isolated from natural products and they have previously been demonstrated to exhibit antimicrobial and antibacterial activity; however, their synthetic preparation has not made them easily amenable to rapid derivatization for SAR studies. Using a combination of solution and solid-supported chemistries, an array of diynes inspired by a known natural product were prepared and assessed for antibacterial activity. Ultimately, several compounds were identified with improved activity in bacterial viability assays. Moreover, some compounds were discovered that displayed a degree of specificity for E. coli over P. fluorescens and vice versa. These new compounds show promise, and further investigation is needed to pinpoint the specific structural components that elicit biological activity.

Development of Simple and Accurate in Silico Ligand-Based Models for Predicting ABCG2 Inhibition

The ATP binding cassette transporter ABCG2 is a physiologically important drug transporter that has a central role in determining the ADMET (absorption, distribution, metabolism, elimination, and toxicity) profile of therapeutics, and contributes to multidrug resistance. Thus, development of predictive in silico models for the identification of ABCG2 inhibitors is of great interest in the early stage of drug discovery. In this work, by exploiting a large public dataset, a number of ligand-based classification models were developed using partial least squares-discriminant analysis (PLS-DA) with molecular interaction field- and fingerprint-based structural description methods, regarding physicochemical and fragmental properties related to ABCG2 inhibition. An in-house dataset compiled from recently experimental studies was used to rigorously validated the model performance. The key molecular properties and fragments favored to inhibitor binding were discussed in detail, which was further explored by docking simulations. A highly informative chemical property was identified as the principal determinant of ABCG2 inhibition, which was utilized to derive a simple rule that had a strong capability for differentiating inhibitors from non-inhibitors. Furthermore, the incorporation of the rule into the best PLS-DA model significantly improved the classification performance, particularly achieving a high prediction accuracy on the independent in-house set. The integrative model is simple and accurate, which could be applied to the evaluation of drug-transporter interactions in drug development. Also, the dominant molecular features derived from the models may help medicinal chemists in the molecular design of novel inhibitors to circumvent ABCG2-mediated drug resistance.

Structural diversity, biosynthesis, and function of plant falcarin-type polyacetylenic lipids

The polyacetylenic lipids falcarinol, falcarindiol, and associated derivatives, termed falcarins, have a widespread taxonomical distribution in the plant kingdom and have received increasing interest for their demonstrated health-promoting properties as anti-cancer and anti-inflammatory agents. These fatty acid-derived compounds are also linked to plant pathogen resistance through their potent antimicrobial properties. Falcarin-type polyacetylenes, which contain two conjugated triple bonds, are derived from structural modifications of the common fatty acid oleic acid. In the past half century, much progress has been made in understanding the structural diversity of falcarins in the plant kingdom, whereas limited progress has been made on elucidating falcarin function in plant-pathogen interactions. More recently, an understanding of the biosynthetic machinery underlying falcarin biosynthesis has emerged. This review provides a concise summary of the current state of knowledge on falcarin structural diversity, biosynthesis, and plant defense properties. We also present major unanswered questions about falcarin biosynthesis and function.

Falcarindiol Isolated from Notopterygium incisum Inhibits the Quorum Sensing of Pseudomonas aeruginosa

Quorum sensing (QS) is employed by the opportunistic pathogen Pseudomonas aeruginosa to regulate physiological behaviors and virulence. QS inhibitors (QSIs) are potential anti-virulence agents for the therapy of P. aeruginosa infection. During the screening for QSIs from Chinese herbal medicines, falcarindiol (the major constituent of Notopterygium incisum) exhibited QS inhibitory activity. The subinhibitory concentration of falcarindiol exerted significant inhibitory effects on the formation of biofilm and the production of virulence factors such as elastase, pyocyanin, and rhamnolipid. The mRNA expression of QS-related genes (lasB, phzH, rhlA, lasI, rhlI, pqsA, and rhlR) was downregulated by falcarindiol while that of lasR was not affected by falcarindiol. The transcriptional activation of the lasI promoter was inhibited by falcarindiol in the P. aeruginosa QSIS-lasI selector. Further experiments confirmed that falcarindiol inhibited the las system using the reporter strain Escherichia coli MG4/pKDT17. Electrophoretic mobility shift assay (EMSA) showed that falcarindiol inhibited the binding of the transcription factor LasR and the lasI promoter region. Molecular docking showed that falcarindiol interacted with the Tyr47 residue, leading to LasR instability. The decrease of LasR-mediated transcriptional activation was responsible for the reduction of downstream gene expression, which further inhibited virulence production. The inhibition mechanism of falcarindiol to LasR provides a theoretical basis for its medicinal application.

Synthesis, Anticancer Activity, Structure-Activity Relationship and Mechanistic Investigations of Falcarindiol Analogues

Forty samples of optically active falcarindiol analogues are synthesized by using the easily available C2 symmetric (R)- and (S)-1,1'-binaphth-2-ol (BINOL) in combination with Ti(Oⁱ Pr)₄ , Zn powder and EtI. Their anticancer activities on Hccc-9810, HepG2, MDA-MB-231, Hela, MG-63 and H460 cells are assayed to elucidate their structure-activity relationships. These results showed that the falcarindiol analogue (3R,8S)-2 i with the terminal double bond has the most potent anti-proliferation effect on Hccc-9810 cells with IC₅₀ value of 0.46 μM. The falcarindiol analogue (3R,8S)-2 i can induce obvious Hccc-9810 cell apoptosis in a concentration-dependent manner by Hoechst staining and flow cytometry analysis. The proposed mechanism suggests that the falcarindiol analogue (3R,8S)-2 i increases LDH release and MDA content, and reduces the levels of SOD activity, which lead to the accumulation of oxidative stress and induce apoptosis in Hccc-9810 cells.

Anticancer Properties of Lobetyolin, an Essential Component of Radix Codonopsis (Dangshen)

Lobetyolin (LBT) is a polyacetylene glycoside found in diverse medicinal plants but mainly isolated from the roots of Codonopsis pilosula, known as Radix Codonopsis or Dangshen. Twelve traditional Chinese medicinal preparations containing Radix Codonopsis were identified; they are generally used to tonify spleen and lung Qi and occasionally to treat cancer. Here we have reviewed the anticancer properties of Codonopsis extracts, LBT and structural analogs. Lobetyolin and lobetyolinin are the mono- and bis-glucosylated forms of the polyacetylenic compound lobetyol. Lobetyol and LBT have shown activities against several types of cancer (notably gastric cancer) and we examined the molecular basis of their activity. A down-regulation of glutamine metabolism by LBT has been evidenced, contributing to drug-induced apoptosis and tumor growth inhibition. LBT markedly reduces both mRNA and protein expression of the amino acid transporter Alanine-Serine-Cysteine Transporter 2 (ASCT2). Other potential targets are proposed here, based on the structural analogy with other anticancer compounds. LBT and related polyacetylene glycosides should be further considered as potential anticancer agents, but more work is needed to evaluate their efficacy, toxicity, and risk-benefit ratio.

Falcarindiol Purified From Carrots Leads to Elevated Levels of Lipid Droplets and Upregulation of Peroxisome Proliferator-Activated Receptor-γ Gene Expression in Cellular Models

Falcarindiol (FaDOH) is a cytotoxic and anti-inflammatory polyacetylenic oxylipin found in food plants of the carrot family (Apiaceae). FaDOH has been shown to activate PPARγ and to increase the expression of the cholesterol transporter ABCA1 in cells, both of which play an important role in lipid metabolism. Thus, a common mechanism of action of the anticancer and antidiabetic properties of FaDOH may be due to a possible effect on lipid metabolism. In this study, the effect of sub-toxic concentration (5 μM) of FaDOH inside human mesenchymal stem cells (hMSCs) was studied using white light microscopy and Raman imaging. Our results show that FaDOH increases lipid content in the hMSCs cells as well as the number of lipid droplets (LDs) and that this can be explained by increased expression of PPARγ2 as shown in human colon adenocarcinoma cells. Activation of PPARγ can lead to increased expression of ABCA1. We demonstrate that ABCA1 is upregulated in colorectal neoplastic rat tissue, which indicates a possible role of this transporter in the redistribution of lipids and increased formation of LDs in cancer cells that may lead to endoplasmic reticulum stress and cancer cell death.

Bioactive C17 and C18 Acetylenic Oxylipins from Terrestrial Plants as Potential Lead Compounds for Anticancer Drug Development

Bioactive C₁₇ and C₁₈ acetylenic oxylipins have shown to contribute to the cytotoxic, anti-inflammatory, and potential anticancer properties of terrestrial plants. These acetylenic oxylipins are widely distributed in plants belonging to the families Apiaceae, Araliaceae, and Asteraceae, and have shown to induce cell cycle arrest and/or apoptosis of cancer cells in vitro and to exert a chemopreventive effect on cancer development in vivo. The triple bond functionality of these oxylipins transform them into highly alkylating compounds being reactive to proteins and other biomolecules. This enables them to induce the formation of anti-inflammatory and cytoprotective phase 2 enzymes via activation of the Keap1–Nrf2 signaling pathway, inhibition of proinflammatory peptides and proteins, and/or induction of endoplasmic reticulum stress, which, to some extent, may explain their chemopreventive effects. In addition, these acetylenic oxylipins have shown to act as ligands for the nuclear receptor PPARγ, which play a central role in growth, differentiation, and apoptosis of cancer cells. Bioactive C₁₇ and C₁₈ acetylenic oxylipins appear, therefore, to constitute a group of promising lead compounds for the development of anticancer drugs. In this review, the cytotoxic, anti-inflammatory and anticancer effects of C₁₇ and C₁₈ acetylenic oxylipins from terrestrial plants are presented and their possible mechanisms of action and structural requirements for optimal cytotoxicity are discussed.

ADMET evaluation in drug discovery. 20. Prediction of breast cancer resistance protein inhibition through machine learning

Breast cancer resistance protein (BCRP/ABCG2), an ATP-binding cassette (ABC) efflux transporter, plays a critical role in multi-drug resistance (MDR) to anti-cancer drugs and drug–drug interactions. The prediction of BCRP inhibition can facilitate evaluating potential drug resistance and drug–drug interactions in early stage of drug discovery. Here we reported a structurally diverse dataset consisting of 1098 BCRP inhibitors and 1701 non-inhibitors. Analysis of various physicochemical properties illustrates that BCRP inhibitors are more hydrophobic and aromatic than non-inhibitors. We then developed a series of quantitative structure–activity relationship (QSAR) models to discriminate between BCRP inhibitors and non-inhibitors. The optimal feature subset was determined by a wrapper feature selection method named rfSA (simulated annealing algorithm coupled with random forest), and the classification models were established by using seven machine learning approaches based on the optimal feature subset, including a deep learning method, two ensemble learning methods, and four classical machine learning methods. The statistical results demonstrated that three methods, including support vector machine (SVM), deep neural networks (DNN) and extreme gradient boosting (XGBoost), outperformed the others, and the SVM classifier yielded the best predictions (MCC = 0.812 and AUC = 0.958 for the test set). Then, a perturbation-based model-agnostic method was used to interpret our models and analyze the representative features for different models. The application domain analysis demonstrated the prediction reliability of our models. Moreover, the important structural fragments related to BCRP inhibition were identified by the information gain (IG) method along with the frequency analysis. In conclusion, we believe that the classification models developed in this study can be regarded as simple and accurate tools to distinguish BCRP inhibitors from non-inhibitors in drug design and discovery pipelines.

Carrot Genotypes Contrasted by Root Color and Grown under Different Conditions Displayed Differential Pharmacological Profiles in Vascular and Metabolic Cells

Carrots' genotype and growing conditions influence their potential properties to fight against cardiovascular and metabolic diseases. The present study evaluated the influence of carrot genotypes contrasted by root color (Bolero, Presto, Karotan, Deep Purple, Kintoki and Blanche des Vosges) growing under standard, water-restricted, biotic stress (Alternaria dauci inoculation), and combined stress conditions (water restriction and A.dauci inoculation). The effect of carrots' polyphenol and carotenoid content was assessed on endothelial and smooth muscle cells, hepatocytes, adipocytes and macrophages functions (oxidative stress, apoptosis, proliferation, lipid accumulation and inflammation). Independently of varieties or growing conditions, all carrot extracts affected vascular cells' oxidative stress and apoptosis, and metabolic cells' oxidative stress and lipid accumulation. Three clusters were revealed and displayed beneficial properties mostly for adipocytes function, smooth muscle cells and hepatocytes, and endothelial cells and hepatocytes, respectively. Karotan and Presto varieties exhibited endothelial tropism while Blanche des Vosges targeted adipocytes. Carrots under biotic stress are more efficient in inducing beneficial effects, with the Bolero variety being the most effective. However, extracts from carrots which grew under combined stress conditions had limited beneficial effects. This report underscores the use of certain carrot extracts as potential effective nutraceutical supplements for metabolic diseases.

Phytochemicals in Daucus carota and Their Health Benefits-Review Article

Carrots are a multi-nutritional food source. They are an important root vegetable, rich in natural bioactive compounds, which are recognised for their nutraceutical effects and health benefits. This review summarises the occurrence, biosynthesis, factors affecting concentration, and health benefits of phytochemicals found in Daucus carota. Two hundred and fifty-five articles including original research papers, books, and book chapters were analysed, of which one hundred and thirty articles (most relevant to the topic) were selected for writing the review article. The four types of phytochemicals found in carrots, namely phenolics, carotenoids, polyacetylenes, and ascorbic acid, were summarised. These chemicals aid in the risk reduction of cancer and cardiovascular diseases due to their antioxidant, anti-inflammatory, plasma lipid modification, and anti-tumour properties. Numerous factors influence the amount and type of phytochemicals present in carrots. Genotype (colour differences) plays an important role; high contents of α and β-carotene are present in orange carrots, lutein in yellow carrots, lycopene in red carrots, anthocyanins in the root of purple carrots, and phenolic compounds abound in black carrots. Carotenoids range between 3.2 mg/kg and 170 mg/kg, while vitamin C varies from 21 mg/kg to 775 mg/kg between cultivars. Growth temperatures of carrots influence the level of the sugars, carotenoids, and volatile compounds, so that growing in cool conditions results in a higher yield and quality of carrots, while higher temperatures would increase terpene synthesis, resulting in carrots with a bitter taste. It is worthwhile to investigate the cultivation of different genotypes under various environmental conditions to increase levels of phytochemicals and enhance the nutritional value of carrot, along with the valorisation of carrot by-products.

Oxygenated C17 polyacetylene metabolites from Algerian Eryngium tricuspidatum L. roots: Structure and biological activity

The secondary metabolite pattern of Eryngium tricuspidatum has been found to be dominated by C₁₇ acetylene oxylipins, according to the chemistry reported in the literature for the genus Eryngium. Two new oxylipins, 11-acetoxy-falcarindiol (4) and 1,2-dihydro-11-acetoxy-falcarindiol (5) have been isolated, along with main related polyacetylenes 1-3 and the already known monoterpene aldehydes 6-10, from the petroleum ether extract of roots. The structure and the absolute configuration of compounds 4 and 5 have been determined by spectroscopic methods as well as by comparison with related known compounds. Polyacetylenes 1-4 inhibited significantly the in vitro growth of a series of cancer cell lines, ranging from 0.3 to 29 μM, whereas 5 was inactive.

The Antitumor Natural Compound Falcarindiol Disrupts Neural Stem Cell Homeostasis by Suppressing Notch Pathway

Neural stem cells (NSCs) are undifferentiated, multi-potent cells that can give rise to functional neurons and glial cells. The disruption in NSC homeostasis and/or the impaired neurogenesis lead to diverse neurological diseases, including depression, dementia, and neurodegenerative disorders. Falcarindiol (FAD) is a polyacetylene found in many plants, and FAD shows the cytotoxicity against breast cancers and colon cancers. However, there is no research on the consequence of FAD treatment in normal stem cells. Here, we suggest that FAD has anticancer roles against glioblastoma cells by inducing the differentiation of glioblastoma stem-like cells, as well as activating apoptosis pathway in glioblastoma cells. On the other hand, we also show that FAD has detrimental effects by disrupting the maintenance of normal NSCs and altering the balance between self-renewal and differentiation of NSCs.

Falcarinol Is a Potent Inducer of Heme Oxygenase-1 and Was More Effective than Sulforaphane in Attenuating Intestinal Inflammation at Diet-Achievable Doses

Nuclear factor- (erythroid-derived 2) like 2 (Nrf2) is a transcription factor that regulates the expression of a battery of antioxidant, anti-inflammatory, and cytoprotective enzymes including heme oxygenase-1 (Hmox1, Ho-1) and NADPH:quinone oxidoreductase-1 (Nqo1). The isothiocyanate sulforaphane (SF) is widely understood to be the most effective natural activator of the Nrf2 pathway. Falcarinol (FA) is a lesser studied natural compound abundant in medicinal plants as well as dietary plants from the Apiaceae family such as carrot. We evaluated the protective effects of FA and SF (5 mg/kg twice per day in CB57BL/6 mice) pretreatment for one week against acute intestinal and systemic inflammation. The phytochemical pretreatment effectively reduced the magnitude of intestinal proinflammatory gene expression (IL-6, Tnfα/Tnfαr, Infγ, STAT3, and IL-10/IL-10r) with FA showing more potency than SF. FA was also more effective in upregulating Ho-1 at mRNA and protein levels in both the mouse liver and the intestine. FA but not SF attenuated plasma chemokine eotaxin and white blood cell growth factor GM-CSF, which are involved in the recruitment and stabilization of first-responder immune cells. Phytochemicals generally did not attenuate plasma proinflammatory cytokines. Plasma and intestinal lipid peroxidation was also not significantly changed 4 h after LPS injection; however, FA did reduce basal lipid peroxidation in the mesentery. Both phytochemical pretreatments protected against LPS-induced reduction in intestinal barrier integrity, but FA additionally reduced inflammatory cell infiltration even below negative control.

Oplopanax horridus: Phytochemistry and Pharmacological Diversity and Structure-Activity Relationship on Anticancer Effects

Oplopanax horridus, well-known as Devil's club, is probably the most important ethnobotanical to most indigenous people living in the Pacific Northwest of North America. Compared with the long history of traditional use and widespread distribution in North America, the study of O. horridus is relatively limited. In the past decade, some exciting advances have been presented on the phytochemistry and pharmacological diversity and structure-activity relationship on anticancer effects of O. horridus. To date, no systematic review has been drafted on the recent advances of O. horridus. In this review, the different phytochemicals in O. horridus are compiled, including purified compounds and volatile components. Animal and in vitro studies are also described and discussed. Especially, the potential structural-activity relationship of polyynes on anticancer effects is highlighted. This review aimed to provide comprehensive and useful information for researching O. horridus and finding potential agents in drug discovery.

Panaxynol, a natural Hsp90 inhibitor, effectively targets both lung cancer stem and non-stem cells

Cancer stem-like cells (CSCs) contribute to tumor recurrence and chemoresistance. Hence, strategies targeting CSCs are crucial for effective anticancer therapies. Here, we demonstrate the capacities of the non-saponin fraction of Panax ginseng and its active principle panaxynol to inhibit Hsp90 function and viability of both non-CSC and CSC populations of NSCLC in vitro and in vivo. Panaxynol inhibited the sphere forming ability of NSCLC CSCs at nanomolar concentrations, and micromolar concentrations of panaxynol suppressed the viability of NSCLC cells (non-CSCs) and their sublines carrying acquired chemoresistance with minimal effect on normal cells derived from various organs. Orally administered panaxynol significantly reduced lung tumorigenesis in Kras^G12D/+ transgenic mice and mice carrying NSCLC xenografts without detectable toxicity. Mechanistically, panaxynol disrupted Hsp90 function by binding to the N-terminal and C-terminal ATP-binding pockets of Hsp90 without increasing Hsp70 expression. These data suggest the potential of panaxynol as a natural Hsp90 inhibitor targeting both the N-terminal and C-terminal of Hsp90 with limited toxicities.

Dietary Guidelines for Breast Cancer Patients: A Critical Review

Current dietary guidelines for breast cancer patients (BCPs) fail to address adequate dietary intakes of macro- and micronutrients that may improve patients' nutritional status. This review includes information from the PubMed and Biomed Central databases over the last 15 y concerning dietary guidelines for BCPs and the potential impact of a personalized, nutrient-specific diet on patients' nutritional status during and after antineoplastic treatment. Results indicated that BCPs should receive a nutritional assessment immediately after diagnosis. In addition, they should be encouraged to pursue and maintain a healthy body weight [body mass index (BMI; in kg/m²) 20-24.9], preserving their lean mass and avoiding an increase in fat mass. Therefore, after nutritional status diagnosis, a conservative energy restriction of 500-1000 kcal/d could be considered in the dietary intervention when appropriate. Based on the reviewed information, we propose a personalized nutrition intervention for BCPs during and after antineoplastic treatment. Specifications in the nutritional therapy should be based on the patients' nutritional status, dietary habits, schedule, activities, and cultural preferences. BCPs' daily energy intake should be distributed as follows: <30% fat/d (mainly monounsaturated and polyunsaturated fatty acids), ∼55% carbohydrates (primarily whole foods such as oats, brown rice, and fruits), and 1.2-1.5 g protein ⋅ kg^-1 ⋅ d^-1 to avoid sarcopenic obesity. Findings suggest that 5-9 servings/d of fruits (∼150 g/serving) and vegetables (∼75 g/serving) should be encouraged. Garlic and cruciferous vegetables must also be part of the nutrition therapy. Adequate dietary intakes of food-based macro- and micronutrients rich in β-carotene and vitamins A, E, and C can both prevent deterioration in BCPs' nutritional status and improve their overall health and prognosis.

ABCG2/BCRP: Specific and Nonspecific Modulators

Multidrug resistance (MDR) in cancer cells is the development of resistance to a variety of structurally and functionally nonrelated anticancer drugs. This phenomenon has become a major obstacle to cancer chemotherapy seriously affecting the clinical outcome. MDR is associated with increased drug efflux from cells mediated by an energy-dependent mechanism involving the ATP-binding cassette (ABC) transporters, mainly P-glycoprotein (ABCB1), the MDR-associated protein-1 (ABCC1), and the breast cancer resistance protein (ABCG2). The first two transporters have been widely studied already and reviews summarized the results. The ABCG2 protein has been a subject of intense study since its discovery as its overexpression has been detected in resistant cell lines in numerous types of human cancers. To date, a long list of modulators of ABCG2 exists and continues to increase. However, little is known about the clinical consequences of ABCG2 modulation. This makes the design of novel, potent, and nontoxic inhibitors of this efflux protein a major challenge to reverse MDR and thereby increase the success of chemotherapy. The aim of the present review is to describe and highlight specific and nonspecific modulators of ABCG2 reported to date based on the selectivity of the compounds, as many of them are effective against one or more ABC transport proteins.

A-803467, a tetrodotoxin-resistant sodium channel blocker, modulates ABCG2-mediated MDR in vitro and in vivo

ATP-binding cassette subfamily G member 2 (ABCG2) is a member of the ABC transporter superfamily proteins, which has been implicated in the development of multidrug resistance (MDR) in cancer, apart from its physiological role to remove toxic substances out of the cells. The diverse range of substrates of ABCG2 includes many antineoplastic agents such as topotecan, doxorubicin and mitoxantrone. ABCG2 expression has been reported to be significantly increased in some solid tumors and hematologic malignancies, correlated to poor clinical outcomes. In addition, ABCG2 expression is a distinguishing feature of cancer stem cells, whereby this membrane transporter facilitates resistance to the chemotherapeutic drugs. To enhance the chemosensitivity of cancer cells, attention has been focused on MDR modulators. In this study, we investigated the effect of a tetrodotoxin-resistant sodium channel blocker, A-803467 on ABCG2-overexpressing drug selected and transfected cell lines. We found that at non-toxic concentrations, A-803467 could significantly increase the cellular sensitivity to ABCG2 substrates in drug-resistant cells overexpressing either wild-type or mutant ABCG2. Mechanistic studies demonstrated that A-803467 (7.5 μM) significantly increased the intracellular accumulation of [³H]-mitoxantrone by inhibiting the transport activity of ABCG2, without altering its expression levels. In addition, A-803467 stimulated the ATPase activity in membranes overexpressed with ABCG2. In a murine model system, combination treatment of A-803467 (35 mg/kg) and topotecan (3 mg/kg) significantly inhibited the tumor growth in mice xenografted with ABCG2-overexpressing cancer cells. Our findings indicate that a combination of A-803467 and ABCG2 substrates may potentially be a novel therapeutic treatment in ABCG2-positive drug resistant cancers.

Bioactive C₁₇-Polyacetylenes in Carrots (Daucus carota L.): Current Knowledge and Future Perspectives

C17-polyacetylenes (PAs) are a prominent group of oxylipins and are primarily produced by plants of the families Apiaceae, Araliaceae, and Asteraceae, respectively. Recent studies on the biological activity of polyacetylenes have indicated their potential to improve human health due to anticancer, antifungal, antibacterial, anti-inflammatory, and serotogenic effects. These findings suggest targeting vegetables with elevated levels of bisacetylenic oxylipins, such as falcarinol, by breeding studies. Due to the abundant availability, high diversity of cultivars, worldwide experience, and high agricultural yields, in particular, carrot (Daucus carota L.) genotypes are a very promising target vegetable. This paper provides a review on falcarinol-type C17-polyacetylenes in carrots and a perspective on their potential as a future contributor to improving human health and well-being.

Aristolochic acid I is a substrate of BCRP but not P-glycoprotein or MRP2

ETHNOPHARMACOLOGICAL RELEVANCE

Aristolochic acid nephropathy is a severe kidney disease caused by the administration of aristolochic acid, which is widely existed in plants of the Aristolochiaceae family. Aristolochic acid I (AAI) is the main toxic component in aristolochic acid.

AIM OF THE STUDY

The roles of intestinal efflux drug transporters in the transport of AAI are unclear. This study investigates the interaction between AAI and main intestinal efflux transporters.

MATERIALS AND METHODS

Firstly, bidirectional transport of AAI in Caco-2 cell monolayers was investigated. Then, MDCK-MDR1 (gene of P-glycoprotein (P-gp)), MDCK-MRP2 and LLC-PK1-BCRP cell lines were used for further investigation.

RESULTS

In this study, we observed that the efflux ratio of AAI in Caco-2 cell monolayers was 5.8, which indicated that efflux transporters might be involved in the transport of AAI. AAI did not inhibit Rho123 efflux by P-gp and calcein efflux by MRP2, and intracellular accumulation of AAI in P-gp or MRP2 overexpressing cells was not different from their parental cells. These results indicated that AAI was not a substrate of P-gp or MRP2. In contrast, intracellular accumulation of AAI in LLC-PK1-BCRP cells was significantly lower than in their parental cells. The presence of GF120918, a BCRP inhibitor, significantly increased AAI accumulation in BCRP overexpressing cells but not in their parental cells. In addition, bidirectional transport assay of AAI in LLC-PK1-BCRP monolayers showed that the net efflux ratios of AAI were 13.8, 8.0 and 7.0 at 20, 40 and 80 µM AAI, respectively, and decreased to 3.0, 1.9 and 2.0 by the addition of 10 µM GF120918.

CONCLUSIONS

These results indicated that AAI was a substrate of BCRP but not P-gp or MRP2.

Alkynol natural products target ALDH2 in cancer cells by irreversible binding to the active site

Chemical proteomic studies reveal ALDH2 as a molecular target of falcarinol in cancer cells.

Sensory and health properties of steamed and boiled carrots (Daucus carota ssp. sativus)

This study examined the influences of domestic processing conditions applied by consumers on firmness, colour and amount of phytochemicals and liking and sensory attributes intensity rating of carrots. The aim was to identify a cooking method and time that yields carrots with higher amount of β-carotene while maintaining consumer liking. Instrumentally measured firmness and colour showed comparable degradation trends between cooking methods. While boiling showed a significant decrease in the amount β-carotene after 20 min (-19%), steaming maintained the amount (+40%). Cooking method did not show a significant effect on liking and intensity ratings for the majority of the sensory attributes. Medium firm carrots were liked the most and low firm carrots the least. This study demonstrates that for optimum liking, carrots should be in the range of medium firmness. This can be obtained through either cooking methods but steamed carrots possess a higher amount of β-carotene and maintains liking.