Antiproliferative activity of flavonoids: influence of the sequential methoxylation state of the flavonoid structure

Therapeutic effects of flavonoids on pulmonary fibrosis: A preclinical meta-analysis

BACKGROUND

The efficacy of flavonoid supplementation in animal models of pulmonary fibrosis has been demonstrated.

PURPOSE

We conducted a systematic review and meta-analysis to evaluate the efficacy and underlying mechanisms of flavonoids in animal models of bleomycin-induced pulmonary fibrosis.

STUDY DESIGN

Relevant studies (n = 45) were identified from English- and Chinese-language databases from the inception of the database until October 2023.

METHODS

Methodological quality was evaluated using the SYRCLE risk of bias tool. Statistical analyses were conducted using RevMan 5.3 and Stata 17.0. Lung inflammation and fibrosis score were the primary outcome indicators.

RESULTS

Flavonoids can alleviate pathological changes in the lungs. The beneficial effects of flavonoids on pulmonary fibrosis likely relate to their inhibition of inflammatory responses, restoration of oxidative and antioxidant homeostasis, and regulation of fibroblast proliferation, migration, and activation by transforming growth factor β1/mothers against the decapentaplegic homologue/AMP-activated protein kinase (TGF-β1/Smad3/AMPK), inhibitor kappa B alpha/nuclear factor-kappa B (IκBα/NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, interleukin 6/signal transducer/activator of transcription 3 (IL6/STAT3), and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathways.

CONCLUSION

Flavonoids are potential candidate compounds for the prevention and treatment of pulmonary fibrosis. However, extensive preclinical research is necessary to confirm the antifibrotic properties of natural flavonoids.

Effects of apigenin on gastric cancer cells

Gastric Cancer (GC) is one of the most prevalent cancers worldwide. As the currently available therapeutic options are invasive, new and more benign options are being explored. One of which is Apigenin (Api), a natural flavonoid found in fruits and vegetables, such as celery, parsley, garlic, bell pepper and chamomile tea. Api has known anti-inflammatory, -oxidant, and -proliferative proprieties in several diseases and its potential as an anticancer compound has been explored. Here we systematize the available data regarding the effects of Api on GC cells, in terms of cell proliferation, apoptosis, Helicobacter pylori (H. pylori) infection, and molecular targets. From the literature it is possible to conclude that Api inhibits cell growth in a dose- and time-dependent manner, which is accompanied by the reduction of clone formation and induction of apoptosis. This occurs through the Akt/Bad/Bcl2/Bax axis that activates the mitochondrial pathway of apoptosis, resulting in restriction of cell proliferation. Additionally, it seems that the anti-proliferative potential of Api on GC cells is particularly relevant in a more aggressive GC phenotype but can also affect normal gastric cells. This indicate that this flavonoid must be used in low-to-moderate doses to avoid side-effects induced by disturbance of the normal epithelium. In H. Pylori-infected cells, the literature demonstrates that Api reduces inflammation by diminishing the levels of H. pylori colonization, by preventing NF-kB activation and by diminishing the production of reactive oxygen specimens (ROS). Accordingly, in GC Api seems to regulate different hallmarks of cancer, such as cell proliferation, apoptosis, cell migration, inflammation and oxidative stress, demonstrating its potential has an anti-GC compound.

Optimization of Flavonoid Extraction from Eucommia ulmoides pollen using Respond Surface Methodology and its biological activities

Flavonoids, known for their abundance in Eucommia ulmoides pollen, possess diverse biological functions, including antioxidants, antibacterial agents, and anti-tumor properties. This study aims to establish effective parameters for flavonoid extraction from Eucommia ulmoides pollen using a microwave-assisted method, characterize the flavonoid composition of the extracted material, and explore its biological activities. Building upon the initial results from single-factor experiments, response surface methodology was employed to optimize the extraction parameters. The inhibitory effect of human breast cancer cells (MCF-7) was evaluated by CCK assay and Live/dead staining. Simultaneously, the extract's scavenging ability against DPPH free radicals and its antibacterial properties against Escherichia coli and Staphylococcus aureus were investigated. The results demonstrated that the flavonoid yield reached 3.28 g per 100 g of pollen, closely aligning with the predicted value. The IC50 for flavonoid-mediated DPPH radical scavenging was 0.04 mg/mL. The extract exhibited a robust inhibitory effect on both Escherichia coli and Staphylococcus aureus. Concurrently, the extract displayed a significant inhibitory effect on the growth and proliferation of MCF-7 cells in a dose-dependent and time-dependent manner. In addition, six kinds of flavonoids have been identified by UPLC-TOF-MS/MS technology, providing further support to the study on the anti-oxidation and anti-tumor mechanism of Eucommia ulmoides pollen extracts.

Stevia rebaudiana leaves fermented by Lactobacillus plantarum exhibit resistance to microorganisms and cancer cell lines in vitro: A potential sausage preservative

Natural preservatives are causing a rethinking of current preservation means. As a sweetener resource, exploitation of Stevia rebaudiana leaves (SRLs) is still restricted due to human conventional cognition. Herein, Lactobacillus plantarum fermented SRLs containing diverse free secondary metabolites derived from microbial deglycosylation and bioenzymatic decomposition were investigated. The apparent resistance to typical foodborne bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomoas aeruginosa, Bacillus amyloliquefaciens) by fermented SRLs and their extracts were validated. The metabolite diversity and in-depth organic solvent extraction gave the possibilities for better antimicrobial actions, anti-HepG2/SGC-7901 cells in vitro in contrast with aqueous extract of unfermented SRLs. Crucially, compound identification and attribution revealed that fermentation products may be maximally contributing to antimicrobial and antitumor mechanisms rather than intrinsic plant and/or microbial components. Additionally, pork sausage models with 15 g/kg ethyl acetate extract as a preservative candidate presented preferred storage characteristics (21 days and 37 °C) compared to those without ethyl acetate extract, e.g. the minimal total plate count (3.86 ± 0.27 log CFU/g), peroxsignide value (8.02 ± 0.92 meq/kg), and acid value (2.01 ± 0.04 (KOH)/(mg/g)).

A review on medicinally important heterocyclic compounds and importance of biophysical approach of underlying the insight mechanism in biological environment

Heterocyclic derivatives have more interesting biological properties which hold a remarkable place in pharmaceutical industries due to their unique physiochemical properties and ease of adaption in various biological environments. Of many, the above-said derivatives have been recently examined for their promising action against a few malignancies. Specifically, anti-cancer research has benefited from these derivatives' natural flexibility and dynamic core scaffold. In any case, concerning some other promising anti-cancer drugs, heterocyclic derivative doesn't come without deficiencies. To be a successful drug candidate it should poses Absorption, Distribution, Metabolism and Eliminations (ADME) parameter, and must also have good binding interaction towards carrier protein as well as DNA and less in toxic nature, economically feasible. In this review, we described the overview of biologically important heterocyclic derivatives and their main application in medicine. Further, we focus types of biophysical techniques to understand the binding interaction mechanism.Communicated by Ramaswamy H. Sarma.

Natural Flavonoid Derivatives Have Pan-Coronavirus Antiviral Activity

The SARS-CoV-2 protease (3CLpro) is one of the key targets for the development of efficacious drugs for COVID-19 treatment due to its essential role in the life cycle of the virus and exhibits high conservation among coronaviruses. Recent studies have shown that flavonoids, which are small natural molecules, have antiviral activity against coronaviruses (CoVs), including SARS-CoV-2. In this study, we identified the docking sites and binding affinity of several natural compounds, similar to flavonoids, and investigated their inhibitory activity towards 3CLpro enzymatic activity. The selected compounds were then tested in vitro for their cytotoxicity, for antiviral activity against SARS-CoV-2, and the replication of other coronaviruses in different cell lines. Our results showed that Baicalein (100 μg/mL) exerted strong 3CLpro activity inhibition (>90%), whereas Hispidulin and Morin displayed partial inhibition. Moreover, Baicalein, up to 25 μg/mL, hindered >50% of SARS-CoV-2 replication in Vero E6 cultures. Lastly, Baicalein displayed antiviral activity against alphacoronavirus (Feline-CoV) and betacoronavirus (Bovine-CoV and HCoV-OC43) in the cell lines. Our study confirmed the antiviral activity of Baicalein against SARS-CoV-2 and demonstrated clear evidence of its pan-coronaviral activity.

Non-Volatile Terpenoids and Lipophilic Flavonoids from Achillea erba-rotta Subsp. moschata (Wulfen) I. Richardson

Musk yarrow (Achillea erba-rotta subsp. moschata (Wulfen) I. Richardson) is endemic to the Central Alps, and is used to flavour alcoholic beverages. Despite its popularity as aromatizing agent and its alleged beneficial effects on digestion, the phytochemical profile of the plant is still largely unknown and undiscovered. As a consequence, its authentication in aromatized products is impossible beyond sensory analysis allowing forgery. To address these issues, we phytochemically characterized a sample of musk yarrow from the Italian Eastern Alps, identifying, in addition to widespread phytochemicals (taraxasterol, apigenin), the guaianolides 3, 8, 9; the seco-caryophyllane 6; and the polymethoxylated lipophilic flavonoids 1, 4, and 5. The flavonoid xanthomicrol 1, a major constituent of the plant, was cytotoxic to HeLa cells, but only modestly affected primary 3T3 fibroblasts. On account of their stability, detectability by UV absorption, and concentration, the oxygenated flavonoids qualify as markers to validate the supply chain of the plant growers to consumers.

Xanthomicrol Activity in Cancer HeLa Cells: Comparison with Other Natural Methoxylated Flavones

The methoxylated flavone xanthomicrol represents an uncommon active phenolic compound identified in herbs/plants with a long application in traditional medicine. It was isolated from a sample of Achillea erba-rotta subsp. moschata (musk yar-row) flowering tops. Xanthomicrol promising biological properties include antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. This study mainly focused on the evaluation of the xanthomicrol impact on lipid metabolism in cancer HeLa cells, together with the investigation of the treatment-induced changes in cell growth, morphology, and apoptosis. At the dose range of 5-100 μM, xanthomicrol (24 h of incubation) significantly reduced viability and modulated lipid profile in cancer Hela cells. It induced marked changes in the phospholipid/cholesterol ratio, significant decreases in the levels of oleic and palmitic acids, and a marked increase of stearic acid, involving an inhibitory effect on de novo lipogenesis and desaturation in cancer cells. Moreover, marked cell morphological alterations, signs of apoptosis, and cell cycle arrest at the G2/M phase were observed in cancer treated cells. The bioactivity profile of xanthomicrol was compared to that of the anticancer methoxylated flavones eupatilin and artemetin, and structure-activity relationships were underlined.

Dracocephalum kotschyi Boiss. In Vitro Efficacy on Growth and Apoptosis Induction in Leishmania major Promastigotes

Dracocephalum kotschyi Boiss. is a plant generally used in modern medicine to treat many human illnesses. It is also used to prevent tumor cell proliferation throughout the world. This study's objective was to evaluate this plant's in vitro efficacy on growth and apoptosis induction in Leishmania major promastigotes. To do this, the essential oil is extracted for the test following the collection and identification of D. kotschyi. The essential oil was analyzed using a GC-MS analyzer. Promastigotes of L. major were cultured in RPMI-1640 media, and the MTT assay and a flow cytometry analysis were carried out on promastigotes that had entered the log phase. To differentiate between viable, necrotic, and apoptotic treated or untreated promastigotes, the flow cytometry method of double staining with annexin V-FLUOS and propidium iodide (PI) was used. Given the results obtained, 11 phytochemicals were identified in the essential oil of this plant. Copaene (22.15%), methyl geranate (16.31%), geranial (13.78%), and carvone (11.34%) were the main substances. The essential oil of D. kotschyi inhibits the proliferation of L. major promastigotes at 921 μg/mL, 252 μg/mL, and 416 μg/mL, respectively, after 24 h, 48 h, and 78 h. The cells were divided into four quadrates based on cell phases using the flow cytometry approach by double staining with annexin V-FLUOS and propidium iodide (PI): necrosis (Q1), late apoptosis (Q2), early apoptosis (Q3), and viable (Q4) quadrates. Overall, it is apparent that the different concentrations induced cell apoptosis in promastigotes. Observation under the light microscope at ×100 magnification showed that the different doses of D. kotschyi essential oil caused apparent alterations in the treated promastigotes. In this work, D. kotschyi essential oils induce programmed death on L. major promastigotes. This study opens many research perspectives, such as investigating the mechanisms of action and the production of a phytomedicine based on this plant.

The Current State of Knowledge in Biological Properties of Cirsimaritin

The search for natural plant-based products as new pharmacological alternatives to treat various human pathologies has taken on great importance for researchers and research laboratories. In this context, research has intensified to extract and identify natural molecules endowed with biological effects. The objective of this study is to review the source and pharmacological properties of cirsimaritin. The identification and isolation of this flavonoid from various natural sources, including medicinal plants such as Artemisia judaica, Cirsium japonicum, Lithocarpus dealbatus, Microtea debilis, and Ocimum sanctum, has been carried out and verified using different spectral techniques. Biological effect investigations are carried out with a wide variety of experimental models in vitro and in vivo and laboratory techniques. The results of these research works showed the biological properties of cirsimaritin including anticancer, antimicrobial, antidiabetic, antiparasitic, antioxidant, and anti-inflammatory effects. The mechanisms involved in the multiple activities of this molecule are diverse and include sub-cellular, cellular, and molecular levels. Indeed, this bioactive induces anti-inflammatory and antiproliferative effects by inhibiting cell membrane receptors, interference with signaling pathways, and inhibiting transcriptional factors such as Nf-κB involved in cell promotion and proliferation. In the light of these results, cirsimaritin appears as a promising and viable alternative natural bioactive drug to treat many pathological conditions.

Anti-Inflammatory Properties of MSF, a Lactiplantibacillus plantarum K8 Lysate Fermented with Filipendula glaberrima Extract

Inflammation plays an important role in the pathogenesis of metabolic syndrome, which increases the risk of heart disease, stroke, type 2 diabetes, atherosclerosis, non-alcoholic fatty liver disease (NAFLD), and obesity. Here, we produced potent anti-inflammatory probiotic lysates, termed MSF (miracle synergistic material made using Filipendula glaberrima), using fermentation with F. glaberrima extracts. MSF inhibited lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production through down-regulation of c-Jun N-terminal kinase (JNK) signaling. MSF-induced tolerance for TNF-α was mediated by induction of TNF alpha-induced protein 3 (TNFAIP3 or A20). On the other hand, MSF showed a synergistic effect on interleukin (IL)-1β production in LPS-stimulated human monocytic leukemia cell line (THP-1 cells). This synergistic effect of the combination of MSF and LPS might be mediated by nuclear factor kappa B (NF-kB) signaling. The inhibitory effect of TNF-α and synergistic effect of IL-1β due to combining MSF and LPS were significantly higher than those of a combination of L. plantarum K8 lysates and LPS. The MSF and LPS combination showed reduced mouse mortality compared to a combination of L. plantarum K8 lysates and LPS, which correlated with decreased levels of cytokines, hepatic alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in the blood and liver. These results show that probiotic lysates fermented with natural extracts such as F. glaberrima have higher anti-inflammatory efficacy than conventional probiotic lysates or natural extracts.

Plants from Genus Dracocephalum in Iran: Pharmacology and Phytochemistry Overview

BACKGROUND

Genus Dracocephalum belongs to the Lamiaceae family, representing 11 species in Iran, containing D. ghahremanii Jamzad, D. lindbergii Rech. F, D. oligadenium Bornm. & Gauba, D. kotschyi Boiss., D.multicaule, D.Aucheri, D.Subcapitatum, D.Thymifolium, D.Moldavica, D. polychaetum Borm, and D. surmandinum Rech.f. The current study aimed to investigate the morphological and phytochemical properties of Dracocephalum species in Iran and their pharmacological effects.

METHODS

The search was restricted to scientific articles from PubMed, Google Scholar, Science Direct, SpringerLink, and Scopus. The search was limited to scientific journals, books, and book chapters focusing on the medicinal properties of Dracocephalum in Iran for the era from 1993 to 2020.

RESULTS

Findings show that Dracocephalum species were utilized to treat various disorders in traditional medicine. Phytochemical studies show that the main constituents isolated from the plant consist of lignans, phytosterol, flavonoids, phenols, alkaloids, Sesquiterpenes, and oxygenated and hydro carbonated monoterpenes. These main components are responsible for antihyperlipidemic, antimicrobial, anticancer, antispasmodic, antioxidant, and cardiovascular effects of the plant.

CONCLUSION

This plant has a good potential for drug discovery and curing different diseases. Therefore, more research will be done on the Iranian species of Dracocephalum based on clinical and animal studies to develop an effective drug formulation.

Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cells

Flavonoids are bioactive secondary metabolites of plants, which exert anti‐cancer effects. However, metabolism in enterocytes and the liver can influence the biological activity of flavonoids contained in the diet. Therefore, results from in vitro studies on cancer cells from the digestive tract and liver may reflect the real effects in the human body. Previously, we have found that the extract from birch buds exerts antiproliferative activity in a panel of cancer cells. In the present study, the anti‐cancer activity of ten flavonoids isolated from the buds of Betula pubescens and Betula pendula was characterized. Among them, santin and cirsimaritin significantly reduced viability, proliferation and clonogenicity of gastric (AGS), colon (DLD‐1) and liver (HepG2) cancer cells. Both flavonoids induced apoptosis, accompanied by activation of caspase‐3, caspase‐7, caspase‐8 and caspase‐9. Moreover, upregulation of p53 was detected only in wild‐type p53 harbouring cells. Together, our results suggest that santin and cirsimaritin exhibit promising anti‐cancer activity in cultures of digestive system cancer cells.

Inductive effect of titanium dioxide nanoparticles on the anticancer compounds production and expression of rosmarinic acid biosynthesis genes in Dracocephalum kotschyi transformed roots

Methoxylated flavonoids, mainly xanthomicrol and cirsimaritin that can be extracted from Dracocephalum kotschyi Boiss, have anticancer, antispasmodic and antiplatelet effects. The production of these valuable pharmaceutical compounds is one of the major goals of biotechnology studies. In this work, induced transformed roots were influenced by various concentrations of titanium dioxide nanoparticles (TiO2 NPs) at 24 or 48 h exposure time. The effects of TiO2 NPs were assessed on growth rate, activity of antioxidant enzymes, total phenol and flavonoid content (TPC and TFC) and rosmarinic acid (RA) and some flavonoids accumulation. The gene expression level of phenylalanine ammonia-lyase (pal) and rosmarinic acid synthase (ras) genes were assessed by real time PCR analysis. The transformed roots biomass was substantially increased in elicited roots in comparison with the control. The TPC, TFC and antioxidant enzymes activitywere affected by TiO2 NPs concentration and exposure time. Valuable flavonoids with anticancer characteristics along with xanthomicrol, cirsimaritin and isokaempferide exhibited an increase (70, 34.28 and 7.81-fold, respectively) versus the control. The maximum content of RA (530.5 μg g-1 FW), which was 4.30 times as great as that of control was detected in samples treated with TiO2 NPs (50 mg L-1) 24 h after elicitation. Real-time PCR analysis revealed a considerable increase in pal and ras expression rate engaged by TiO2 NPs levels and exposure time. Overall D. kotschyi transformed roots elicitation by TiO2 NPs led to a massive increment in the production of valuable anticancer flavonoids such as xanthomicrol, cirsimaritin and RA as polyphenol.

Polymethoxyflavones in Citrus Regulate Lipopolysaccharide-Induced Oscillating Decay of Circadian Rhythm Genes by Inhibiting Nlrp3 Expression

The aim of this study is to compare the regulatory abilities of citrus flavonoids on the oscillating expression of circadian genes. Seven varieties of citrus fruits and twenty-five citrus flavonoids were selected and evaluated. Per2 luciferase bioluminescence report system and serum shock were used to induce circadian gene expression in mouse microglia BV-2 cells. In vivo experiments were carried out using C57BL6/J mice to evaluate the regulation of flavonoids on the oscillatory expression of liver biorhythm genes. Lipopolysaccharide was used to interfere the gene oscillating expression. QRT-PCR was performed to detect the expression of circadian rhythm-related genes, including Clock, Bmal1, Per1, Per2, Per3, Cry1, Cry2, Rev-erbα, Rev-erbβ, Rorα, Dbp, and Npas2. The results show that the polymethoxyflavones (PMFs) exerted stronger circadian gene regulatory capability, while the flavonoids containing glycosides showed no biological activity. Also, all tested flavonoids decreased LPS-induced nitric oxide release, but only polymethoxyflavones inhibited circadian rhythm disorder. PMFs inhibited Nlrp3 inflammasome-related genes and proteins, including Nlrp3, IL-1β, ASC, and Caspase1, while other flavonoids only affected IL-1β and Caspase1 expression. This mechanism was preliminarily verified using the Nlrp3 inhibitor INF39.

Breast cancer cell line toxicity of a flavonoid isolated from Baccharis densiflora

Background

Flavonoids are compounds of interest in the search for new anti-cancer therapies. We have previously isolated the methoxyflavones 5,4′-dihydroxy-6,7,8,3′-tetramethoxyflavone (8-methoxycirsilineol), 5,4′-dihydroxy-6,7,8-trimethoxyflavone (xanthomicrol), and 5,4,'3′-trihydroxy-6,7,8-trimethoxyflavone (sideritoflavone) from Baccharis densiflora. Herein, we investigate the toxicity of these methoxyflavones in human breast-derived cell line. Our main aim was to focus on the cancer stem cell (CSC) sub-population of JIMT-1 breast cancer cells.

Methods

Initially, dose response experiments yielding inhibitory concentration 50 (IC₅₀) values were performed using MCF-7, HCC1937, and JIMT-1 breast cancer, and the MCF-10A normal-like breast cell lines to get an understanding of toxic ranges. Due to a clear difference in the toxicity of the flavones, only sideritoflavone was selected for further studies using the JIMT-1 cell line. Effects on the CSC sub-population was investigated using flow cytometry-based methods. A wound healing assay and digital holographic microscopy were used to investigate effects on cell movement. A reporter assay was used to study effects on signal transduction pathways and Western blot for protein expression.

Results

The dose response data showed that 8-methoxycirsilineol was non-toxic at concentrations below 100 μM, that the IC₅₀ of xanthomicrol was between 50 and 100 μM, while sideritoflavone was highly toxic with a single digit μM IC₅₀ in all cell lines. Treatment of the JIMT-1 cells with 2 μM sideritoflavone did not selectively effect the CSC sub-population. Instead, sideritoflavone treatment inhibited the proliferation of both the non-CSC and the CSC sub-populations to the same extent. The inhibition of cell proliferation resulted in an accumulation of cells in the G₂ phase of the cell cycle and the treated cells showed an increased level of γ-H2A histone family member X indicating DNA double strand breaks. Analysis of the effect of sideritoflavone treatment on signal transduction pathways showed activation of the Wnt, Myc/Max, and transforming growth factor-β pathways. The level of p65/nuclear factor kappa-light-chain-enhancer of activated Β cells was increased in sideritoflavone-treated cells. Cell movement was decreased by sideritoflavone treatment.

Conclusions

Altogether our data show that the methoxyflavone sideritoflavone has favourable anti-cancer effects that may be exploited for development to be used in combination with CSC specific compounds.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03349-4.

Chitosan stimulates secondary metabolite production and nutrient uptake in medicinal plant Dracocephalum kotschyi

BACKGROUND

A wide variety of secondary metabolites are synthesized from primary metabolites by plants which have a vast range in pharmaceutical, food additive and industrial applications. In recent years, the use of elicitors has opened a novel approach for the production of secondary metabolite compounds. Dracocephalum kotschyi is a valuable herb due to pharmaceutical compounds like rosmarinic acid, quercetin and apigenin. In the current study, foliar application of chitosan (0, 100, 400 mg L-1 ) as an elicitor was used.

RESULTS

After chitosan treatment, the amounts of hydrogen peroxide (H2 O2 ) increased and the plant was able to increase the activities of enzymatic (guaiacol peroxidase, catalase and phenylalanine ammonium lyase) and non-enzymatic (total phenols and flavonoids) defensive metabolites. Also, foliar spray of chitosan promoted nutrient absorption which led to the accumulation of macroelements in the plant.

CONCLUSIONS

Chitosan was found to be a very effective elicitor for improving rosmarinic acid and quercetin content (up to 13-fold). Also, the content of apigenin (anticancer flavonoid) showed 16-fold enhancement compared to the control. Therefore, the treatment of D. kotschyi leaves with chitosan caused a very large increase in the induction and production of important pharmaceutical compounds such as rosmarinic acid and quercetin. © 2020 Society of Chemical Industry.

Ethanolic Extracts of Adlay Testa and Hull and Their Active Biomolecules Exert Relaxing Effect on Uterine Muscle Contraction through Blocking Extracellular Calcium Influx in Ex Vivo and In Vivo Studies

Dysmenorrhea is one of the most prevalent disorders in gynecology. Historically, adlay (Coix lachryma-jobi L. var. Ma-yuen Stapf.) has been explored for its anti-tumor, pain relief, anti-inflammatory, and analgesic effects. The aim of this study was to evaluate the effects of adlay seeds on the inhibition of uterine contraction and thus dysmenorrhea relief, in vitro and in vivo. HPLC-MS and GC were used to elucidate the ethyl acetate fraction of adlay testa ethanolic extract (ATE-EA) and ethyl acetate fraction of adlay hull ethanolic extract (AHE-EA). Elucidation yielded flavonoids, phytosterols, and fatty acids. Uterine leiomyomas and normal adjacent myometrial tissue were evaluated by oxytocin- and PG-induced uterine contractility. ATE-EA and AHE-EA suppressed uterine contraction induced by prostaglandin F2 alpha (PGF_2α), oxytocin, carbachol, and high-KCl solution ex vivo. In addition, the external calcium (Ca²⁺) influx induced contraction, and increased Ca²⁺ concentration was inhibited by ATE-EA and AHE-EA on the uterine smooth muscle of rats. Furthermore, ATE-EA and AHE-EA effectively attenuated the contraction of normal human myometrium tissues more than adjacent uterine leiomyoma in response to PGF_2α. 3,5,6,7,8,3′,4′-Heptamethoxyflavone and chrysoeriol produced a remarkable inhibition with values of IC₅₀ = 24.91 and 25.59 µM, respectively. The experimental results showed that treatment with ATE-EA at 30 mg/day effectively decreased the writhing frequency both on the oxytocin-induced writhing test and acetic acid writhing test of the ICR mouse.

Analysis of Peganum harmala, Melia azedarach and Morus alba extracts against six lethal human cancer cells and oxidative stress along with chemical characterization through advance Fourier Transform and Nuclear Magnetic Resonance spectroscopic methods towards green chemotherapeutic agents

Traditional medicines implicate consumption of plant crude extracts, which may consist of extensive phytochemical diversity. Overall, the most biologically active extract of Peganum harmala (seeds) exhibited significant cytotoxic activity on Artemia salina with LC50 value of 61.547 µg/mL, while P. harmala (roots) [LC50 = 124.229 µg/mL] and M. azedarach (fruits) [LC50 = 147.813 µg/mL] showed moderate cytotoxic potential. P. harmala (seeds) extract also showed the maximum antitumor potential with 52.278 µg/mL LC50. Branches of P. harmala and Morus alba were not active in both bioassays. These outcomes were further reinforced by the levels of phenolics and flavonoids checked against gallic acid and quercetin equivalents, respectively, by standard curves. Current study aims to isolate, structurally characterize and analyze the bioactive compound from plant extracts by using chromatographic and spectrophotometric techniques. Bioactivity guided isolation of extracts led to the isolation of PH-HM-16 from ethyl acetate fraction P. harmala seeds. Chemical structure of PH-HM-16 was elucidated by ESI-MS, 1H NMR, 13C NMR, HSQC and IR spectrum. The results demonstrated significant positive anticancer activities against six human cancer cell lines assessed through MTT cancer cell growth inhibition assay. PH-HM-16 was most effective against prostate cancer cell lines [IC50 = 17.63 µg/mL] followed by breast cancer cell line MCF7 [IC50 value of 41.81 µg/mL]. IC50 value of PH-HM-16 against human myeloid leukemia cell line HL-60 and human colorectal tumor cells HCT-116 was observed as 68.77 µg/mL and 71.54 µg/mL respectively. The IC 50 value of PH-HM-16 compound was not significant against human gastric cancer SGC-7901 (111.89 µg/mL) and human lung adenocarcinoma epithelial cell line A549 (176.04 µg/mL). Isolated bioactive metabolite PH-HM-16 possesses significant antitumor potential so this could be the first step to develop an effective anticancer agent. Hence, this compound represents a promising potential to be chemically standardized or developed into pharmaceuticals for the chemoprevention and/or the treatment of certain types of cancer, especially as adjuvant phytotherapeutics in conventional chemotherapy.

Flavonoid Calycopterin Induces Apoptosis in Human Prostate Cancer Cells In-vitro

Prostate cancer is enumerated as one of the most prevalent cancers in men, with a mortality rate of 18%. Chemotherapy is considered as a common strategy for cancer treatment; however, toxic side effects and drug resistance associated with chemotherapy are major drawbacks with this approach. It is well known that a diet rich in flavonoids can reduce the incidence of many types of cancer in a significant manner, and it was proved that methoxy flavones have greater bioavailability compared to the nonmethylated ones. Calycopterin is a tetramethoxy flavone which was demonstrated to have anti-proliferative effects on colon, gastric, and osteosarcoma cancer cells. Therefore, in the current study, we have evaluated the apoptotic effects of this flavonoid on two prostate cancer cell lines in-vitro. The MTT assay revealed that after 48 h treatment with this flavonoid, cell viability reduced to 50% compared to the control group. However, calycopterin treatment of healthy HUVEC did not cause any significant reduction in cell viability. Moreover, the clonogenic assay demonstrated that after 14 days, colony size and numbers reduced significantly in calycopterin treated cells. In addition, the percentage of the sub-G1 population in calycopterin-treated cells augmented significantly compared to untreated group. Also, calycopterin-treated cells demonstrated shiny condensed nuclei with fragmented DNA indicative of apoptosis. Finally, a significant reduction in the migration ability was observed in both lines subjected to calycopterin after 48 h. To conclude, our results demonstrated the apoptotic and anti-metastatic effects of calycopterin in both hormone-dependent and independent prostate cancer cell lines.

Flavonoids Targeting HIF-1: Implications on Cancer Metabolism

Tumor hypoxia is described as an oxygen deprivation in malignant tissue. The hypoxic condition is a consequence of an imbalance between rapidly proliferating cells and a vascularization that leads to lower oxygen levels in tumors. Hypoxia-inducible factor 1 (HIF-1) is an essential transcription factor contributing to the regulation of hypoxia-associated genes. Some of these genes modulate molecular cascades associated with the Warburg effect and its accompanying pathways and, therefore, represent promising targets for cancer treatment. Current progress in the development of therapeutic approaches brings several promising inhibitors of HIF-1. Flavonoids, widely occurring in various plants, exert a broad spectrum of beneficial effects on human health, and are potentially powerful therapeutic tools against cancer. Recent evidences identified numerous natural flavonoids and their derivatives as inhibitors of HIF-1, associated with the regulation of critical glycolytic components in cancer cells, including pyruvate kinase M2(PKM2), lactate dehydrogenase (LDHA), glucose transporters (GLUTs), hexokinase II (HKII), phosphofructokinase-1 (PFK-1), and pyruvate dehydrogenase kinase (PDK). Here, we discuss the results of most recent studies evaluating the impact of flavonoids on HIF-1 accompanied by the regulation of critical enzymes contributing to the Warburg phenotype. Besides, flavonoid effects on glucose metabolism via regulation of HIF-1 activity represent a promising avenue in cancer-related research. At the same time, only more-in depth investigations can further elucidate the mechanistic and clinical connections between HIF-1 and cancer metabolism.

Xanthomicrol Exerts Antiangiogenic and Antitumor Effects in a Mouse Melanoma (B16F10) Allograft Model

Xanthomicrol, a trimethoxylated hydroxyflavone, is the main active component of Dracocephalum kotschyi Boiss leaf extract. Preliminary in vitro studies identified this compound as a potential antiangiogenic and anticancer agent. This study aimed to evaluate in vivo anticancer effect of xanthomicrol and investigate its molecular mechanism of action in a mouse melanoma (B16F10) model. Effect of xanthomicrol on B16F10 melanoma cell viability was determined using the MTT assay. For in vivo experiments, C57BL/6 mice were inoculated subcutaneously with B16F10 cells. After five days, once daily administration of xanthomicrol, thalidomide, or vehicle was commenced and continued for 21 consecutive days. On the 26th day, blood samples and tumor biopsies were taken for subsequent molecular analysis. Xanthomicrol showed inhibitory effect on viability of B16F10 melanoma cells (IC50 value: 3.433 μg/ml). Initial tumor growth, tumor volume and weight, and angiogenesis were significantly decreased in xanthomicrol-treated animals compared with those in vehicle group. Protein expression of phosphorylated Akt, mRNA expressions of HIF-1α and VEGF in tumor tissues, and serum VEGF were significantly decreased in xanthomicrol-treated animals compared with vehicle-treated animals. Thus, xanthomicrol inhibited cancer cell growth both in vitro and in vivo. This effect, at least in part, was exerted by interfering with PI3K/Akt signaling pathway and inhibiting VEGF secretion by tumor cells. Further studies are required to elucidate the exact molecular mechanisms of antitumor activity of xanthomicrol.

Flavonoid calycopterin triggers apoptosis in triple-negative and ER-positive human breast cancer cells through activating different patterns of gene expression

Breast cancer is the most common cause of death related to cancer in women, and several studies proved that flavonoids could induce apoptosis in this cancer through different pathways. Calycopterin is a flavonoid which was shown to induce preferential antiproliferative effects on some cancers; however, no information is available on its effect on breast cancer. Therefore, in this paper, the apoptotic effect of calycopterin and its underlying mechanism in two different breast cancer cells, MDA-MB-231 and MCF7 cell lines were investigated. MTT assay showed that calycopterin reduced the proliferation of both cancer lines with no adverse effect on normal cells. The clonogenic assay showed that calycopterin treatments decreased the colony numbers and sizes, and wound healing assay demonstrated the inhibition of migration in both cancer cells. Cell cycle and annexin/PI analyses indicated that calycopterin augmented sub-G1 population and annexin/PI-positive cells. Gene expression revealed that Bax/Bcl2 increased in the MDA-MB-231 cell line, while no change was observed in that of the MCF7 line. Expression of gene caspase-8 was augmented in both lines, although increased expression of caspase-3 was found just in MDA-MB-231 cells. Our results validated the apoptotic effect of calycopterin on both breast cancer lines with more potency on triple-negative ones.

Phytochemical Profile and Biological Activity of Endemic Sideritis sipylea Boiss. in North Aegean Greek Islands

Sideritis sipylea Boiss. is an endemic plant of the Mediterranean basin that is distributed in the Greek islands of the North Aegean Sea, i.e., Lesvos, Chios, Samos, and Ikaria, and in the West and Middle peninsula of Turkey. It is considered an endangered species because of its uncontrolled collection from its original habitat. Although the antioxidant, anti-inflammatory and antimicrobial properties have been previously reported, the total chemical profile has not yet been explored. In this context, the chemical profiles of the water/methanol (HA), methanol (ME), and ethyl acetate (EtOAc) extracts were analyzed using ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS). In parallel, analysis by gas chromatography-mass spectrometry (GC-MS) was employed for the dichloromethane extract (DCM) as well as for the essential oil (EO) and the extract obtained by supercritical fluid extraction (SFE). Furthermore, the total phenolic content (TPC) along with the in vitro tyrosinase and elastase enzyme inhibitory activity of different extracts was evaluated, towards the discovery of new active agents for cosmetic formulations. These activities are in accordance with its well-known antioxidant and anti-inflammatory properties, confirming the importance of ethnopharmacological references for S. sipylea in Greece and Turkey.

In vitro anticancer potentiality and molecular modelling study of novel amino acid derivatives based on N1,N3-bis-(1-hydrazinyl-1-oxopropan-2-yl) isophthalamide

A series of N¹,N³-bis (1-oxopropan-2-yl) isophthalamide-based derivatives 4–16 were prepared and their structures were confirmed by different spectral tools. The cytotoxic potentiality of novel compounds 4–16 was assessed by the MTT assay method on colon, lung and breast tumour cell lines. Compound 5 gave the most significant specificity anticancer activity with safety response on normal cell lines. In vitro enzyme assay and several apoptotic parameters were examined to elucidate the mode of action of compound 5. Molecular docking studies also were simulated to put insight and give better understanding to its structural features.

Medicinal Properties and Active Constituents of Dracocephalum kotschyi and Its Significance in Iran: A Systematic Review

OBJECTIVES

Dracocephalum has over 60 species and is found mainly in the temperate regions of Asia and Europe. One of these species, i.e., Dracocephalum kotschyi Boiss, is known to have a number of medicinal properties and active ingredients in many parts of the world. Despite being an endemic wild-flowering plant of great importance, the plant is currently considered endangered in Iran. Besides, there is paucity of information on the significance of the medicinal properties and active constituents of D. kotschyi among the Iranian people. On that account a systematic review of studies reporting on the medicinal properties and active ingredients and its significance to human and animal health was conducted and the existing knowledge gaps were identified.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used in the search for published articles on medicinal properties and active ingredients of D. kotschyi and its significance on humans and animals in Iran. The search was confined to scientific articles from repositories of popular data bases and search engines among them PubMed, Web of Science, Google Scholar, Science Direct, SpringerLink, and Scopus. The search narrowed down on scientific journals, books, and book chapters focusing on the medicinal properties of D. kotschyi in Iran for the period between 1970 and 2018.

RESULTS

A total of 1158 scientific articles were sourced from the various databases, out of which 38 met the search criteria and qualified for this review. The studies were conducted in only 9 of the 31 provinces of Iran, with a large proportion in Isfahan province, central Iran. The studies showed that all plant parts (roots, aerial parts, flowers, and leaves) had active constituents. Essential oils and aerial plant parts were the main components studied. Nevertheless, the most frequently reported constituents were xanthomicrol, limonene, luteolin, geranial, apigenin, and calycopterin. A number of medicinal properties were reported among them antioxidant, antibacterial, anticancerous, antinociceptive, antihyperlipidemic, antispasmodic, cytotoxic, and immunomodulatory effects. The plant was also reported to be a remedy for inflammatory pain, headaches, congestion, liver disorders, ulcer, fever, renal pain, dyspepsia, stomach ache, abdominal pain, joints pains, muscle spasm, congestion, bloating, and wound healing effects, among others.

CONCLUSION

This review has shown that D. kotschyi is an important medicinal plant with a large number of active constituents and great potential to safeguard human and animal health in Iran. However, over utilization of the D. kotschyi plant is already endangering its existence. Nevertheless, more studies need be conducted across the country.

Cytotoxic Flavonoids from the Aerial Parts of Stachys lavandulifolia Vahl

Background: Stachys lavandulifolia Vahl is a herbaceous plant distributed in the west and south western Asia. Despite of the wide medicinal uses, there are some reports on toxicity potential of this plant. In present study we attempted to evaluate the toxicity and to characterize the cytotoxic principles of S. lavandulifolia. Methods: Brine shrimp lethality test (BSLT) was used to evaluate the general toxicity of the extracts and essential oil obtained from the aerial parts of S. lavandulifolia. Phytochemical constituents of the active extract were investigated using various chromatographic and spectroscopic methods. GC and GC-MS were also used to analyze the plant essential oil. GC and GC-MS were used to analyze the plant essential oil. Cytotoxic activities of the isolated compounds were also evaluated using MTT assay method. Results: In brine shrimp lethality test (BSLT), chloroform extract and the plant essential oil exhibited the most toxicity against Artemia salina larvae (LD50: 121.8±5.6 and 127.6±14.7 µg ml-1, respectively). GC and GC-MS analyses of essential oil led to the characterization of forty compounds of which α-bisabolol (23.85%) and thymol (17.88%) were identified as the main constituents. Nine flavonoids, Pachypodol (1), chrysosplenetin (2), kumatakenin (3), velutin (4), penduletin (5), viscosine (6), chrysoeriol (7), hydroxygenkwanin (8) and apigenin (9) were isolated from the chloroform extract of S. lavandulifolia. Among the isolated compounds, chrysosplenetin (2), a polymethoxylated flavonoid, was found as the most toxic compound toward MDA-MB-23 and HT-29 cells, with IC50 values of 88.23 and 116.50 µg ml-1, respectively. Furthermore, chrysosplenetin (2), kumatakenin (3) and viscosine (6) with selectivity indices of 2.70, 2.59 and 3.33, respectively, showed higher preferential toxicity against MDA-MB-23 cells in comparison with tamoxifen (SI:2.45). Conclusion: This study reports methoxylated flavonoids as compounds which could be involved in toxicity of S. lavandulifolia. The results of MTT assay also suggest some of these compounds as appropriate candidates for anti-cancer drug development research.

Flavonoid Extract from Propolis Inhibits Cardiac Fibrosis Triggered by Myocardial Infarction through Upregulation of SIRT1

The flavonoid extract from propolis (FP) has been shown to protect against heart injury induced by isoproterenol. However, the effect of FP on cardiac fibrosis after myocardial infarction (MI) as well as the underlying mechanisms is not known. In the present study, we used biochemical and histological approaches to examine the effects of FP on MI-induced cardiac fibrosis and the related mechanisms in a rat MI model and in angiotensin II- (Ang II-) treated rat cardiac fibroblasts (CFs). In vivo, MI was generated by ligation of the left anterior descending coronary artery of rats, which remained for 4 weeks. Rats were randomly divided into the sham, MI, FP (12.5 mg/kg/d), and MI+FP groups. We found that FP treatment improved heart function, reduced cardiac fibrosis, and downregulated the expression of fibrosis-related factors including collagen I, collagen III, matrix metalloproteinase-2 (MMP-2), MMP-9, transforming growth factor-β1 (TGF-β1), and p-Smad2/3, which coincided with the upregulated expression of silent information regulator 1 (SIRT1) in the hearts of MI rats. Our in vitro experiments showed that FP inhibited the proliferation and migration of primary cultured rat CFs and downregulated the expression of the above-mentioned fibrosis-related factors in Ang II-stimulated CFs. In addition, FP can decrease ROS production induced by MI and Ang II in vivo and vitro. Notably, silencing SIRT1 counteracted the FP-induced effects on CFs treated with Ang II. We conclude that FP inhibits MI-induced cardiac fibrosis through SIRT1 activation and that FP represents a potential promising drug for the treatment of MI patients in the clinic.

Synthesis and Antiproliferative Activity of Minor Hops Prenylflavonoids and New Insights on Prenyl Group Cyclization

Synthesis of minor prenylflavonoids found in hops and their non-natural derivatives were performed. The antiproliferative activity of the obtained compounds against some human cancer cell lines was investigated. Using xanthohumol isolated from spent hops as a lead compound, a series of minor hop prenylflavonoids and synthetic derivatives were obtained by isomerization, cyclisation, oxidative-cyclisation, oxidation, reduction and demethylation reactions. Three human cancer cell lines-breast (MCF-7), prostate (PC-3) and colon (HT-29)-were used in antiproliferative assays, with cisplatin as a control compound. Five minor hop prenyl flavonoids and nine non-natural derivatives of xanthohumol have been synthetized. Syntheses of xanthohumol K, its dihydro- and tetrahydro-derivatives and 1″,2″,α,β-tetrahydroxanthohumol C were described for the first time. All of the minor hops prenyl flavonoids exhibited strong to moderate antiproliferative activity in vitro. The minor hops flavonoids xanthohumol C and 1″,2″-dihydroxanthohumol K and non-natural 2,3-dehydroisoxanthohumol exhibited the activity comparable to cisplatin. Results described in the article suggest that flavonoids containing chromane- and chromene-like moieties, especially chalcones, are potent antiproliferative agents. The developed new efficient, regioselective cyclisation reaction of the xanthohumol prenyl group to 1″,2″-dihydroxantohumol K may be used in the synthesis of other compounds with the chromane moiety.

Anti-Cancer Activity of Lobaric Acid and Lobarstin Extracted from the Antarctic Lichen Stereocaulon alpnum

Lobaric acid and lobarstin, secondary metabolites derived from the antarctic lichen Stereocaulon alpnum, exert various biological activities, including antitumor, anti-proliferation, anti-inflammation, and antioxidant activities. However, the underlying mechanisms of these effects have not yet been elucidated in human cervix adenocarcinoma and human colon carcinoma. In the present study, we evaluated the anticancer effects of lobaric acid and lobarstin on human cervix adenocarcinoma HeLa cells and colon carcinoma HCT116 cells. We show that the proliferation of Hela and HCT116 cells treated with lobaric acid and lobarstin significantly decreased in a dose- and time-dependent manner. Using flow cytometry analysis, we observed that the treatment with these compounds resulted in significant apoptosis in both cell lines, following cell cycle perturbation and arrest in G2/M phase. Furthermore, using immunoblot analysis, we investigated the expression of cell cycle and apoptosis-related marker genes and found a significant downregulation of the apoptosis regulator B-cell lymphoma 2 (Bcl-2) and upregulation of the cleaved form of the poly (ADP-ribose) polymerase (PARP), a DNA repair and apoptosis regulator. These results suggest that lobaric acid and lobarstin could significantly inhibit cell proliferation through cell cycle arrest and induction of apoptosis via the mitochondrial apoptotic pathway in cervix adenocarcinoma and colon carcinoma cells. Taken together, our data suggests that lobaric acid and lobarstin might be novel agents for clinical treatment of cervix adenocarcinoma and colon carcinoma.

Development of 1,3,4-oxadiazole thione based novel anticancer agents: Design, synthesis and in-vitro studies

A series of new 1,3,4-oxadiazole-2(3H)-thione analogues (3a to 3o) have been designed, synthesized and evaluated for their anticancer activity. Four different cancerous cell lines viz. HeLa (cervical), U-87 (glioblastoma), Panc (pancreatic) and MCF-7 (breast) were used to assess the potency of the synthesized compounds as anticancer agents. Among them 3i and 3j showed promising cytotoxicity against HeLa cell line. Further, 3i and 3j successfully inhibited cell cycle progression and displayed cell death in HeLa cells via apoptosis as visualized by Annexin V APC and DNA fragmentation assay. 3i and 3j induced caspase-3 activation, PARP cleavage, increase in expression of proapoptotic protein Bax and decrease in the expression of antiapoptotic protein Bcl-2. Also, 3i and 3j induced overexpression of p21 and decreased expression of cyclin B1 indicating the arrest of cells in G₂-M phase of the cell cycle. Therefore, new lead compounds are being suggested having anticancer activity through cell cycle inhibition and apoptosis.

Chemical Characterization and Biological Activities of Phenolic-Rich Fraction from Cauline Leaves of Isatis tinctoria L. (Brassicaceae) Growing in Sicily, Italy

The present work focused on the evaluation of the antioxidant and cytotoxic activities of the phenolic-rich fraction (ItJ-EAF) obtained from cauline leaves collected in January from Isatis tinctoria L. (Brassicaceae) growing wild around Acireale (Sicily, Italy). The total phenolic, flavonoid, and condensed tannin contents of the fraction were determined spectrophotometrically, whereas the phenolic profile was assessed by HPLC-PDA/ESI-MS analysis. A total of 20 compounds were positively identified and twelve out of them were never previously reported in I. tinctoria leaves. The fraction exhibited good radical scavenging activity in DPPH test (IC₅₀  = 0.6657 ± 0.0024 mg/ml) and reducing power (3.87 ± 0.71 ASE/ml), whereas, it neither showed chelating activity nor was able to counteract H₂ O₂ induced oxidative stress damage in Escherichia coli. The antiproliferative effect was evaluated in vitro on two human anaplastic thyroid carcinoma cell lines (CAL-62 and 8505C) by MTT assay. At the highest tested concentration ItJ-EAF significantly reduced (80%) the growth of CAL-62 cells. No cytotoxicity against Artemia salina was observed. It can be concluded that I. tinctoria cauline leaves represent a source of phenolic compounds which could be potentially used as chemopreventive or adjuvant agents against cancer.

Salvia fruticosa Modulates mRNA Expressions and Activity Levels of Xenobiotic Metabolizing CYP1A2, CYP2E1, NQO1, GPx, and GST Enzymes in Human Colorectal Adenocarcinoma HT-29 Cells

Natural products have gained considerable interests because of their use in some industrial areas including nutrition, cosmetic, pharmacy, and medicine. Salvia fruticosa M. (Lamiaceae) is known for its antioxidant, antimicrobial, and antiproliferative activities. Phase I xenobiotic metabolizing enzymes, CYP1A2 and CYP2E1, produce reactive metabolites which are eliminated by the action of phase II enzymes, NQO1, GPx, and glutathione S-transferases (GSTs). In this study, in vitro modulatory effects of S. fruticosa and its major phenolic compound rosmarinic acid (RA) on CYP1A2, CYP2E1, NQO1, GPx, and GSTm1 mRNA expressions and enzyme activities of GPx and GSTs were investigated in HT-29 cells. An mRNA expression analysis revealed that CYP1A2 and CYP2E1 levels were decreased while those of NQO1, GPx, and GSTm1 increased after S. fruticosa and RA treatments. In parallel to gene expressions, enzyme activities of GPx and GSTs by S. fruticosa increased 1.68- and 1.48-fold, respectively. Moreover, RA increased GPx and GSTs activities 1.67- and 1.94-fold, respectively. The results of this preliminary study show that metabolism of xenobiotics may be altered due to changes in the expression and activity of the investigated enzymes by S. fruticosa.

Established Human Cell Lines as Models to Study Anti-leukemic Effects of Flavonoids

Despite the extensive work on pathological mechanisms and some recent advances in the treatment of different hematological malignancies, leukemia continues to present a significant challenge being frequently considered as incurable disease. Therefore, the development of novel therapeutic agents with high efficacy and low toxicity is urgently needed to improve the overall survival rate of patients. In this comprehensive review article, the current knowledge about the anticancer activities of flavonoids as plant secondary polyphenolic metabolites in the most commonly used human established leukemia cell lines (HL-60, NB4, KG1a, U937, THP-1, K562, Jurkat, CCRF- CEM, MOLT-3, and MOLT-4) is compiled, revealing clear anti-proliferative, pro-apoptotic, cell cycle arresting, and differentiation inducing effects for certain compounds. Considering the low toxicity of these substances in normal blood cells, the presented data show a great potential of flavonoids to be developed into novel anti-leukemia agents applicable also in the malignant cells resistant to the current conventional chemotherapeutic drugs.

Pharmacokinetics of calycopterin and xanthmicrol, two polymethoxylated hydroxyflavones with anti-angiogenic activities from Dracocephalum kotschyi Bioss

BACKGROUND

Recently flavonoids have attracted the attention of researchers in the fight against cancer. Calycopterin and xanthomicrol, are two polymethoxylated flavonoids found in the aerial parts of Dracocephalum kotschyi Bioss.. We have recently shown that these compounds possess antiangiogenic activity and may be of value as potential anticancer agents. In order to demonstrate putative in vivo antitumor effect of these compounds we needed preliminary information on both pharmacokinetics and toxicological properties of these two agents.

METHOD

A new online SPE HPLC method for measurement of calycopterin and xanthomicrol in rat plasma was developed. Pharmacokinetic parameters of calycopterin and xanthomicrol, after i.v. administration in rats, were determined.

RESULTS

The plasma half-life for both agents was around 4 h, however, the volume of distribution of calycopterin appeared to be about 8 times greater than xanthomicrol. This was probably due the greater hydrophobicity of the former which had other consequences such as much smaller maximum plasma concentration of calycopterin compared to its less methoxylated congener. Preliminary toxicological study of xanthomicrol failed to show any behavioral, histological and biochemical adverse effects after repeated administrations of high doses. Pharmacokinetics of xanthomicrol in rats.

Comparison of antispasmodic effect of hydroalcoholic extract of Dracocephalum kotschyi Boiss. in rat uterus and ileum

Dracocephalum kotschyi Boiss. is a traditional medicine with antispasmodic activities. The objective of this research was to study antispasmodic activities of hydroalcoholic extract of D. kotschyi on rat isolated uterus contractions for comparison with isolated ileum. Hydroalcoholic extract was obtained from aerial part of D. kotschyi using percolation method. A portion of rat ileum or uterus was suspended in Tyrode's solution at 37°C and gassed with O₂. Effect of D. kotschyi extract was assessed on ileum or uterus contractions induced by KCl (80 mM), acetylcholine (ACh, 500 nM), electrical field stimulation (EFS) or oxytocin (0.0005 IU/mL). The extract of D. kotschyi concentration-dependently inhibited ileum responses to KCl (IC₅₀ = 65 ± 18 μg/mL), ACh (IC₅₀ = 102 ± 18 μg/mL) and EFS (IC₅₀ = 117 ± 29 μg/mL). The extract of D. kotschyi also concentration-dependently inhibited uterus responses to KCl (IC₅₀ = 453 ± 64μg/mL), ACh (IC₅₀ = 58 ± 9 μg/mL), EFS (IC₅₀ = 22 ± 3 μg/mL) as well as oxytocin (IC₅₀ = 70 ± 11 μg/mL). From this experiment it was concluded that D. kotschyi extract possesses antispasmodic activities on both smooth muscle of ileum and uterus. In comparison, the extract was more effective inhibitor of ACh and EFS responses in rat uterus than on the ileum. On the other hand, the extract was a more potent inhibitor of KCl response on rat ileum. However, the extract was found to be a potent inhibitor of oxytocin-induced contraction of rat uterus. These results indicate that D. kotschyi extract may contain components that might be useful lead compounds for prevention of uterus spasm.

Recent applications of 1,3-thiazole core structure in the identification of new lead compounds and drug discovery

1,3-Thiazole is one of the most important scaffolds in heterocyclic chemistry and drug design and discovery. It is widely found in diverse pharmacologically active substances and in some naturally-occurring compounds. Thiazole is a versatile building-block for lead generation, and is easily access of diverse derivatives for subsequent lead optimization. In the recent years, many thiazole derivatives have been synthesized and subjected to varied biological activities. In this article we intended to review the most important biological effects of thiazole-based compounds and highlight their roles in new leads identification and drug discovery. This article is also intended to help researches for finding potential future directions on the development of more potent and specific analogs of thiazole-based compounds for various biological targets.

Methoxyflavones from Stachys glutinosa with binding affinity to opioid receptors: in silico, in vitro, and in vivo studies

Fractionation of the bioactive dichloromethane extract from the aerial parts of Stachys glutinosa led to the isolation of four flavones, xanthomicrol (1), sideritoflavone (2), 8-methoxycirsilineol (3), and eupatilin (4), along with two neo-clerodane diterpenes, roseostachenone (8) and a new compound, 3α,4α-epoxyroseostachenol (7). In order to study structure-activity relationships, two methoxyflavones [5-demethyltangeretin (5) and tangeretin (6)] were synthesized by the methoxylation of xanthomicrol. The isolated compounds (1-4, 7, and 8) as well as the xanthomicrol semisynthetic derivatives (5 and 6) were evaluated for their binding affinity to the μ and δ opioid receptors. Xanthomicrol was the most potent binder to both μ and δ receptors, with a Ki value of 0.83 and 3.6 μM, respectively. Xanthomicrol administered intraperitoneally in mice at a dose of 80 mg/kg significantly reduced morphine-induced antinociception in the tail flick test. Our results suggested that xanthomicrol is a μ opioid receptor antagonist. Docking experiments were carried out to acquire a deeper understanding about important structural aspects of binding of xanthomicrol. In summary, these data suggest that xanthomicrol is a valuable structure for further development into a potential μ opioid receptor antagonist.

Overproduction of valuable methoxylated flavones in induced tetraploid plants of Dracocephalum kotschyi Boiss

BACKGROUND

Ploidy manipulation is considered an efficient method to increase production potential of medicinally important compounds. Dracocephalum kotschyi Boiss. is an endangered medicinal plant of Iran. Various concentrations of colchicine (0.05, 0.10, 0.20, and 0.50% w/v) were applied to shoot apical meristems of D. kotschyi seedlings in two and four-leaf stages to induce tetraploidy.

RESULTS

According to the results, 0.5% (w/v) of colchicine can be effective for polyploidy induction in D. kotschyi. Putative tetraploids were selected by morphological and microscopic characteristics and their ploidy level was confirmed by flow cytometry analysis and chromosome counting. The chromosome number of original diploid plant was confirmed to be 2n = 2× = 20 whereas that of the tetraploid plant was 2n = 4× = 40. Tetraploid and mixoploid plants showed different morphological, physiological and microscopic characteristics from those of diploid counterparts. The total content of flavonoids was increased from 1583.28 in diploids to 1890.07 (μg/g DW) in stable tetraploids.

CONCLUSION

High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) confirmed over accumulation of methoxylated hydroxyflavones in solid tetraploid plants of D. kotschyi.

Correlation of antiangiogenic, antioxidant and cytotoxic activities of some Sudanese medicinal plants with phenolic and flavonoid contents

BACKGROUND

Consumption of medicinal plants to overcome diseases is traditionally belongs to the characteristics of most cultures on this earth. Sudan has been a host and cradle to various ancient civilizations and developed a vast knowledge on traditional medicinal plants. The present study was undertaken to evaluate the antioxidant, antiangiogenic and cytotoxic activities of six Sudanese medicinal plants which have been traditionally used to treat neoplasia. Further the biological activities were correlated with phytochemical contents of the plant extracts.

METHODS

Different parts of the plants were subjected to sequential extraction method. Cytotoxicity of the extracts was determined by dimethylthiazol-2-yl)- 2,5diphenyl tetrazolium bromide (MTT) assay on 2 human cancer (colon and breast) and normal (endothelial and colon fibroblast) cells. Anti-angiogenic potential was tested using ex vivo rat aortic ring assay. DPPH (1,1-diphenyl-2-picrylhydrazyl) assay was conducted to screen the antioxidant capabilities of the extracts. Finally, total phenolic and flavonoid contents were estimated in the extracts using colorimetric assays.

RESULTS

The results indicated that out of 6 plants tested, 4 plants (Nicotiana glauca, Tephrosia apollinea, Combretum hartmannianum and Tamarix nilotica) exhibited remarkable anti-angiogenic activity by inhibiting the sprouting of microvessels more than 60%. However, the most potent antiangiogenic effect was recorded by ethanol extract of T. apollinea (94.62%). In addition, the plants exhibited significant antiproliferative effects against human breast (MCF-7) and colon (HCT 116) cancer cells while being non-cytotoxic to the tested normal cells. The IC50 values determined for C. hartmannianum, N. gluaca and T. apollinea against MCF-7 cells were 8.48, 10.78 and 29.36 μg/ml, respectively. Whereas, the IC50 values estimated for N. gluaca, T. apollinea and C. hartmannianum against HCT 116 cells were 5.4, 20.2 and 27.2 μg/ml, respectively. These results were more or less equal to the standard reference drugs, tamoxifen (IC50 = 6.67 μg/ml) and 5-fluorouracil (IC50 = 3.9 μg/ml) tested against MCF-7 and HCT 116, respectively. Extracts of C. hartmannianum bark and N. glauca leaves demonstrated potent antioxidant effect with IC50s range from 9.4-22.4 and 13.4-30 μg/ml, respectively. Extracts of N. glauca leaves and T apollinea aerial parts demonstrated high amount of flavonoids range from 57.6-88.1 and 10.7-78 mg quercetin equivalent/g, respectively.

CONCLUSIONS

These results are in good agreement with the ethnobotanical uses of the plants (N. glauca, T. apollinea, C. hartmannianum and T. nilotica) to cure the oxidative stress and paraneoplastic symptoms caused by the cancer. These findings endorse further investigations on these plants to determine the active principles and their mode of action.

Synthesis and anti-cancer activity evaluation of new dimethoxylated chalcone and flavanone analogs

A novel series of chalcones and flavanones discriminated by the presence of a 3,4-dimethoxyphenyl moiety in their structures were synthesized as anti-cancer agents. The cytotoxicity evaluation of the analogs against the MCF-7, MDA-MB-231 (human breast cancer), and SK-N-MC (human neuroblastoma) cell lines demonstrated that the introduction of a halogen on the 3,4-dimethoxyphenyl part of both series and the attachment of a pyrrolidinylethoxy group on the C-7 position of the flavanone derivatives increased their activity. Indeed, 3-halogenated chalcones (1c and 1d) were more potent than the standard drug etoposide against all tested cell lines. Fluorescence microscopy and flow cytometry analyses confirmed that the anti-cancer effect of the most potent compounds 1c and 1d occurs via apoptosis induction.