Combined treatment with quercetin and imperatorin as a potent strategy for killing HeLa and Hep-2 cells

Imperatorin from the aerial parts of Cleome viscosa L.: a characterization study and evaluation of the antibacterial activity

Cleome viscosa L., a member of the family Cleomaceae, is a potential medicinal plant, known for several bioactive properties such as: anticancer, antidiabetic, antioxidant, anti-inflammatory, antimicrobial, wound healing, etc. Our study aimed to isolate a bioactive compound and assess its antibacterial activity. The crystal compound imperatorin was isolated and reported for the first time from the aerial parts of C. viscosa. The isolation was made using silica gel (100-200 mesh) column chromatography. The structure of imperatorin was investigated through single-crystal XRD, unit cell molecules, FTIR, and ESI-MS spectral analysis. The results validated imperatorin's triclinic crystal structure and P2i/c distance group. The electronic structure was also calculated (4.28/6.21 D) along with the frontier molecular orbital, dipole moment, atomic charges, and electrostatic map of particles in gaseous stage and active site. Imperatorin showed highest activity at 40 µg/mL concentration against Gram + ve bacteria: Staphylococcus aureus (3 ± 0.2 mm), Bacillus subtilis (3 ± 0.6 mm), and Gram -ve bacteria: Klebsiella pneumoniae (3 ± 0.2 mm), Escherichia coli (5 ± 0.2 mm). The study highlights that the compound can be isolated in larger quantities as the plant is easily available across the tropics.

Nano Drug Delivery Strategies for an Oral Bioenhanced Quercetin Formulation

Quercetin, a naturally occurring flavonoid, has been credited with a wide spectrum of therapeutic properties. However, the oral use of quercetin is limited due to its poor water solubility, low bioavailability, rapid metabolism, and rapid plasma clearance. Quercetin has been studied extensively when used with various nanodelivery systems for enhancing quercetin bioavailability. To enhance its oral bioavailability and efficacy, various quercetin-loaded nanosystems such as nanosuspensions, polymer nanoparticles, metal nanoparticles, emulsions, liposomes or phytosomes, micelles, solid lipid nanoparticles, and other lipid-based nanoparticles have been investigated in in-vitro cells, in-vivo animal models, and humans. Among the aforementioned nanosystems, quercetin phytosomes are attracting more interest and are available on the market. The present review covers insights into the possibilities of harnessing quercetin for several therapeutic applications and a special focus on anticancer applications and the clinical benefits of nanoquercetin formulations.

Advances in autophagy modulation of natural products in cervical cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Natural products play a critical role in drug development and is emerging as a potential source of biologically active metabolites for therapeutic intervention, especially in cancer therapy. In recent years, there is increasing evidence that many natural products may modulate autophagy through various signaling pathways in cervical cancer. Understanding the mechanisms of these natural products helps to develop medications for cervical cancer treatments.

AIM OF THE STUDY

In recent years, there is increasing evidence that many natural products may modulate autophagy through various signaling pathways in cervical cancer. In this review, we briefly introduce autophagy and systematically describe several classes of natural products implicated in autophagy modulation in cervical cancer, hoping to provide valuable information for the development of cervical cancer treatments based on autophagy.

MATERIALS AND METHODS

We searched for studies on natural products and autophagy in cervical cancer on the online database and summarized the relationship between natural products and autophagy modulation in cervical cancer.

RESULTS

Autophagy is a lysosome-mediated catabolic process in eukaryotic cells that plays an important role in a variety of physiological and pathological processes, including cervical cancer. Abnormal expression of cellular autophagy and autophagy-related proteins has been implicated in cervical carcinogenesis, and human papillomavirus infection can affect autophagic activity. Flavonoids, alkaloids, polyphenols, terpenoids, quinones, and other compounds are important sources of natural products that act as anticancer agents. In cervical cancer, natural products exert the anticancer function mainly through the induction of protective autophagy.

CONCLUSIONS

The regulation of cervical cancer autophagy by natural products has significant advantages in inducing apoptosis, inhibiting proliferation, and reducing drug resistance in cervical cancer.

Targeting of non-apoptotic cancer cell death mechanisms by quercetin: Implications in cancer therapy

The ultimate goal of cancer treatment is to kill cancer cells, based on the use of various therapeutic agents, such as chemotherapy, radiotherapy, or targeted therapy drugs. Most drugs exert their therapeutic effects on cancer by targeting apoptosis. However, alterations in apoptosis-related molecules and thus assisting cells to evade death, eventually lead to tumor cell resistance to therapeutic drugs. The increased incidence of non-apoptotic cell death modes such as induced autophagy, mitotic catastrophe, senescence, and necrosis is beneficial to overcoming multidrug resistance mediated by apoptosis resistance in tumor cells. Therefore, investigating the function and mechanism of drug-induced non-apoptotic cell death modes has positive implications for the development of new anti-cancer drugs and therapeutic strategies. Phytochemicals show strong potential as an alternative or complementary medicine for alleviating various types of cancer. Quercetin is a flavonoid compound widely found in the daily diet that demonstrates a significant role in inhibiting numerous human cancers. In addition to direct pro-tumor cell apoptosis, both in vivo and in vitro experiments have shown that quercetin exerts anti-tumor properties by triggering diverse non-apoptotic cell death modes. This review summarized the current status of research on the molecular mechanisms and targets through which quercetin-mediated non-apoptotic mode of cancer cell death, including autophagic cell death, senescence, mitotic catastrophe, ferroptosis, necroptosis, etc.

Network pharmacology reveals the potential mechanism of Baiying Qinghou decoction in treating laryngeal squamous cell carcinoma

Context: Baiying Qinghou as a traditional Chinese medicine decoction shows anticancer property on laryngeal squamous cell carcinoma. However, little is known about the precise mechanism of Baiying Qinghou detection against laryngeal squamous cell carcinoma.

Objective: This study was aimed to explore potential mechanism of therapeutic actions of Baiying Qinghou decoction on laryngeal squamous cell carcinoma.

Materials and Methods: The active chemical components of Baiying Qinghou decoction were predicted, followed by integrated analysis of network pharmacology and molecular docking approach. The network pharmacology approach included target protein prediction, protein-protein interaction network construction and functional enrichment analysis.

Results: Sitosterol and quercetin were predicted to be the overlapped active ingredients among three Chinese herbs of Baiying Qinghou decoction. The target proteins were closely associated with response to chemical, response to drug related biological process and cancer related pathways such as PI3K-Akt signaling, HIF-1 signaling and Estrogen signaling pathway. The target proteins of TP53, EGFR, PTGS2, NOS3 and IL1B as the key nodes in PPI network were cross-validated, among which EGFR, IL1B, NOS3 and TP53 were significantly correlated with the prognosis of patients with laryngeal squamous cell carcinoma. Finally, the binding modes of EGFR, IL1B, NOS3 and TP53 with quercetin were visualized.

Discussion and Conclusion: Quercetin of Baiying Qinghou decoction showed therapeutic effect against laryngeal squamous cell carcinoma by regulating TP53, EGFR, NOS3 and IL1B involved with drug resistance and PI3K-AKT signaling pathway. TP53, EGFR, NOS3 and IL1B may be the candidate targets for the treatment of laryngeal squamous cell carcinoma.

Imperatorin induces autophagy and G0/G1 phase arrest via PTEN-PI3K-AKT-mTOR/p21 signaling pathway in human osteosarcoma cells in vitro and in vivo

BACKGROUND

Osteosarcoma is the third most common cancer in adolescence and the first common primary malignant tumor of bone. The long-term prognosis of osteosarcoma still remains unsatisfactory in the past decades. Therefore, development of novel therapeutic agents which are effective to osteosarcoma and are safe to normal tissue simultaneously is quite essential and urgent.

METHODS

Firstly, MTT assay, cell colony formation assay, cell migration and invasion assays were conducted to evaluate the inhibitory effects of imperatorin towards human osteosarcoma cells. RNA-sequence assay and bioinformatic analysis were then performed to filtrate and assume the potential imperatorin-induced cell death route and signaling pathway. Moreover, quantitative real-time PCR assay, western blot assay and rescue experiments were conducted to confirm the assumptions of bioinformatic analysis. Finally, a subcutaneous tumor-transplanted nude mouse model was established and applied to evaluate the internal effect of imperatorin on osteosarcoma by HE and immunohistochemistry staining.

RESULTS

Imperatorin triggered time-dependent and dose-dependent inhibition of tumor growth mainly by inducing autophagy promotion and G0/G1 phase arrest in vitro and in vivo. Besides, imperatorin treatment elevated the expression level of PTEN and p21, down-regulated the phosphorylation of AKT and mTOR. In contrast, the inhibition of PTEN using Bpv (HOpic), a potential and selective inhibitor of PTEN, concurrently rescued imperatorin-induced autophagy promotion, cell cycle arrest and inactivation of PTEN-PI3K-AKT-mTOR/p21 pathway.

CONCLUSIONS

This work firstly revealed that imperatorin induced autophagy and cell cycle arrest through PTEN-PI3K-AKT-mTOR/p21 signaling pathway by targeting and up-regulating PTEN in human osteosarcoma cells. Hence, imperatorin is a desirable candidate for clinical treatments of osteosarcoma.

Dietary polyphenols in chemoprevention and synergistic effect in cancer: Clinical evidences and molecular mechanisms of action

BACKGROUND

Epidemiological studies has revealed that a diet rich in fruits and vegetables could lower the risk of certain cancers. In this setting, natural polyphenols are potent anticancer bioactive compounds to overcome the non-target specificity, undesirable cytotoxicity and high cost of treatment cancer chemotherapy.

PURPOSE

The review focuses on diverse classifications of the chemical diversity of dietary polyphenol and their molecular targets, modes of action, as well as preclinical and clinical applications in cancer prevention.

RESULTS

The dietary polyphenols exhibit chemo-preventive activity through modulation of apoptosis, autophagy, cell cycle progression, inflammation, invasion and metastasis. Polyphenols possess strong antioxidant activity and control multiple molecular events through activation of tumor suppressor genes and inhibition of oncogenes involved in carcinogenesis. Numerous in vitro and in vivo studies have evidenced that these dietary phytochemicals regulate critical molecular targets and pathways to limit cancer initiation and progression. Moreover, natural polyphenols act synergistically with existing clinically approved drugs. The improved anticancer activity of combinations of polyphenols and anticancer drugs represents a promising perspective for clinical applications against many human cancers.

CONCLUSION

The anticancer properties exhibited by dietary polyphenols are mainly attributed to their anti-metastatic, anti-proliferative, anti-angiogenic, anti-inflammatory, cell cycle arrest, apoptotic and autophagic effects. Hence, regular consumption of dietary polyphenols as food or food additives or adjuvants can be a promising tactic to preclude adjournment or cancer therapy.

Chemical diversity of dietary phytochemicals and their mode of chemoprevention

Despite the advancement in prognosis, diagnosis and treatment, cancer has emerged as the second leading cause of disease-associated death across the globe. With the remarkable application of synthetic drugs in cancer therapy and the onset of therapy-associated adverse effects, dietary phytochemicals have been materialized as potent anti-cancer drugs owing to their antioxidant, apoptosis and autophagy modulating activities. With dynamic regulation of apoptosis and autophagy in association with cell cycle regulation, inhibition in cellular proliferation, invasion and migration, dietary phytochemicals have emerged as potent anti-cancer pharmacophores. Dietary phytochemicals or their synthetic analogous as individual drug candidates or in combination with FDA approved chemotherapeutic drugs have exhibited potent anti-cancer efficacy. With the advancement in cancer therapeutics, dietary phytochemicals hold high prevalence for their use as precision and personalized medicine to replace conventional chemotherapeutic drugs. Hence, keeping these perspectives in mind, this review focuses on the diversity of dietary phytochemicals and their molecular mechanism of action in several cancer subtypes and tumor entities. Understanding the possible molecular key players involved, the use of dietary phytochemicals will thrive a new horizon in cancer therapy.

Systems Pharmacology Study of the Anticervical Cancer Mechanisms of FDY003

Increasing data support that herbal medicines are beneficial in the treatment of cervical cancer; however, their mechanisms of action remain to be elucidated. In the current study, we used a systems pharmacology approach to explore the pharmacological mechanisms of FDY003, an anticancer herbal formula comprising Lonicera japonica Thunberg, Artemisia capillaris Thunberg, and Cordyceps militaris (Linn.) Link, in the treatment of cervical cancer. Through the pharmacokinetic assessment of absorption-distribution-metabolism-excretion characteristics, we found 18 active compounds that might interact with 106 cervical cancer-related targets responsible for the pharmacological effects. FDY003 targets were significantly associated with gene ontology terms related to the regulation of cellular behaviors, including cell proliferation, cell cycle processes, cell migration, cell apoptosis, cell death, and angiogenesis. The therapeutic targets of the herbal drug were further enriched in various oncogenic pathways that are implicated in the tumorigenesis and progression of cervical cancer, including the phosphatidylinositol 3-kinase, mitogen-activated protein kinase, focal adhesion, human papillomavirus infection, and tumor necrosis factor signaling pathways. Our study provides a systematic approach to explore the anticancer properties of herbal medicines against cervical cancer.

Imperatorin Relieved Ulcerative Colitis by Regulating the Nrf-2/ARE/HO-1 Pathway in Rats

Ulcerative colitis is a common intestinal inflammatory disease. Imperatorin (IMP) has been reported to alleviate mast cell-mediated allergic responses by suppressing the expression of Nrf-2, ARE, and HO-1. However, whether IMP can relieve ulcerative colitis by regulating Nrf-2/ARE/HO-1 pathway is unclear. Thus, this study aims to investigate the effect of IMP on ulcerative colitis in rats and elucidate the potential mechanism. In our study, rats were treated with 2,4,6-trinitro-benzenesulfonic acid (TNBS) to induce the animal model of ulcerative colitis. Next, these rats were treated with diverse doses of IMP (15 mg/kg, 30 mg/kg, and 60 mg/kg) and sacrificed at different time points (3 days, 7 days, and 14 days). The levels of inflammatory factors (TNF-α and IL-6) in colon tissues were detected with ELISA kits. H&E staining was performed to observe the pathologic changes of the colon tissues. The expression of Nrf-2, ARE, and HO-1 in colon tissues was determined with the immunofluorescence and Western blotting. The results showed that application of IMP alleviated the symptoms of ulcerative colitis and inhibited the secretion of TNF-α and IL-6. Besides, treatment of IMP promoted the expression of Nrf-2, ARE, and HO-1 in the early stage of this disease (the third day), but suppressed the expression of Nrf-2, ARE, and HO-1 in the advanced stage of the ulcerative colitis (the fourteenth day). Collectively, IMP relieved the symptoms of ulcerative colitis by regulating the Nrf-2/ARE/HO-1 pathway, which might provide a new therapeutic drug to support the clinical treatment of ulcerative colitis.

Inhibitory Effect of Imperatorin on the Pharmacokinetics of Diazepam In Vitro and In Vivo

Background

Diazepam is a benzodiazepine drug used to treat anxiety, insomnia, and muscle spasms. Imperatorin is a phytochemical isolated from medicinal plants and is widely used in herbal medicine. The aim of this study was to investigate the interactions between imperatorin and diazepam in vitro and in vivo and to provide evidence-based guidance for the safe clinical use of the drug.

Methods

In vitro inhibition of imperatorin was assessed by incubating rat liver microsomes with diazepam to determine IC₅₀ values and the type of inhibition. For in vivo assessment, six rats were pretreated with 50 mg/kg imperatorin for two weeks, six were administered saline, and a single dose of 10 mg/kg diazepam was administered orally to both groups 30 min after the administration of imperatorin.

Results

Imperatorin inhibited the in vitro metabolism of diazepam via the competitive mechanism of CYP450. The IC₅₀ values of imperatorin to nordazepam and temazepam were 1.54 μM and 1.80 μM, respectively. The inhibitory constant values for temazepam and nordazepam were 1.24 μM and 1.29 μM, respectively. Long-term administration of imperatorin significantly increased the AUC_(0-12h), AUC_(0-∞), and Cmax of diazepam, while Vz/F and CLz/F were decreased significantly (P < 0.05). In turn, the AUC_(0-12h), AUC_(0-∞), and Cmax of nordazepam and temazepam decreased significantly, and Vz/F and CLz/F increased significantly (P < 0.05).

Conclusions

This study demonstrates that imperatorin inhibits the metabolism of diazepam both in vitro and in vivo. These results indicated that more attention should be paid when taking diazepam together with food or herbs containing IMP, although further investigation is still needed.

Imperatorin as a Promising Chemotherapeutic Agent Against Human Larynx Cancer and Rhabdomyosarcoma Cells

Naturally occurring coumarins are bioactive compounds widely used in Asian traditional medicine. They have been shown to inhibit proliferation, induce apoptosis, and/or enhance the cytotoxicity of currently used drugs against a variety of cancer cell types. The aim of our study was to examine the antiproliferative activity of different linear furanocoumarins on human rhabdomyosarcoma, lung, and larynx cancer cell lines, and dissolve their cellular mechanism of action. The coumarins were isolated from fruits of Angelica archangelica L. or Pastinaca sativa L., and separated using high-performance counter-current chromatography (HPCCC). The identity and purity of isolated compounds were confirmed by HPLC-DAD and NMR analyses. Cell viability and toxicity assessments were performed by means of methylthiazolyldiphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. Induction of apoptosis and cell cycle progression were measured using flow cytometry analysis. qPCR method was applied to detect changes in gene expression. Linear furanocoumarins in a dose-dependent manner inhibited proliferation of cancer cells with diverse activity regarding compounds and cancer cell type specificity. Imperatorin (IMP) exhibited the most potent growth inhibitory effects against human rhabdomyosarcoma and larynx cancer cell lines owing to inhibition of the cell cycle progression connected with specific changes in gene expression, including CDKN1A. As there are no specific chemotherapy treatments dedicated to laryngeal squamous cell carcinoma and rhabdomyosarcoma, and IMP seems to be non-toxic for normal cells, our results could open a new direction in the search for effective anti-cancer agents.

Imperatorin: A review of its pharmacology, toxicity and pharmacokinetics

As a naturally occurring furanocoumarin, the medicinal value of imperatorin has been studied more and more. We hope to provide useful information for the further development of imperatorin by analyzing the literature of imperatorin in recent years. By collating the literature on the pharmacology of imperatorin, we found that the pharmacological activity of imperatorin is wide and imperatorin can be used for anti-cancer, neuroprotection, anti-inflammatory, anti-hypertension and antibacterial. In addition, we found that some researchers confirmed the toxicity of imperatorin. Pharmacokinetic studies demonstrated that oxidation metabolism is the main metabolic pathways of imperatorin. At present, the shortcomings of research on imperatorin mainly include: most pharmacological studies are concentrated in vitro, lacking enough in vivo experimental data; more and more studies showed that imperatorin has synergistic effect with other drugs in anticancer and other aspects, but lacking the detailed explanation of the mechanism of the synergistic effect; imperatorin has side effect, but it lacks enough experimental conclusions. Based on the above defects, we believe that more in vivo experiments of imperatorin should be carried out in the future; future research need to explore synergistic mechanisms of imperatorin with other drugs, especially in anticancer; the dose affects both the pharmacological activity and the side effect of imperatorin. The relationship between the dose and the two aspects need to be further studied in order to reduce the side effect. In addition, through structural modification of imperatorin, it is possible to improve the treatment effect and reduce side effect.

Furanocoumarins in anticancer therapy - For and against

Furanocoumarins are a class of natural compounds produced by several plants, including those consumed by humans. They have been used medicinally in eastern countries for ages. Given the growing body of evidence about their anticancer potential and observations that naturally occurring compounds potentiate the antitumor activity of chemotherapeutics, more attention is paid to elucidation of the nature of furanocoumarins and the possibility of using thereof in practice. The general mechanism by which furanocoumarins eliminate cancer cells is based on cell cycle blockage and initiation of programmed death like apoptosis or autophagy. The precise molecular mechanism of such an action depends on the chemical structure of furanocoumarins, which is based on the furan ring attached to the coumarin backbone in a linear or angular form as well as the type, location, and number of the substituents attached. The review summarizes the current evidence of the antitumor properties of linear and angular furanocoumarins with special emphasis on the molecular mechanism of elimination of cancer cells via apoptosis and autophagy. Negative aspects of the use of coumarins in anticancer therapy will be also discussed especially in the context of their phototoxicity and potential cancerogenic effect.

Imperatorin improves in vitro porcine embryo development by reducing oxidative stress and autophagy

Imperatorin (IMP), a furanocoumarin derivative with many biological properties and pharmacological activities, is widely used as an antibacterial, anti-inflammatory, antiviral, anticancer, cardiovascular and neuroprotective agent. The purpose of this study was to explore the effects of IMP on early embryo development in pigs as well as the potential mechanisms. Our results showed that IMP can enhance the developmental competence of porcine early embryos. Supplementation of in vitro culture medium with 40 μM IMP significantly increased the blastocyst rate and total cell number. At the same time, apoptosis of blastocysts was also significantly decreased in the supplemented group compared with the control group, in accordance with the subsequent results of FAS and CASP3 gene expression analysis. Furthermore, IMP attenuated intracellular reactive oxygen species (ROS) generation, increased fluorescein diacetate (FDA) and glutathione (GSH) levels. Importantly, IMP not only improved the activity of mitochondria but also inhibited the occurrence of autophagy. In addition, pluripotency-related genes (OCT4, NANOG, and SOX2) and a growth and metabolism regulatory gene (mTOR) were upregulated after IMP supplementation on Day 7. These results demonstrate that IMP exerts a beneficial effect on preimplantation embryo development by reducing oxidative stress and autophagy.

Effects of imperatorin in the cardiovascular system and cancer

Patients with cancer survivors are at increased risk of cardiovascular disease(CVD). Cardio-oncology has developed as a new discipline with the advances in cancer treatment. There are many new challenges for the clinician and a new frontier for research and investigation. There is an urgent need for further study on the prevention of cardiovascular toxicity. Imperatorin (IMP) is a natural form of coumarin and extract from several plants with diver's pharmacokinetic effects, including antioxidant and anti-inflammatory properties. This review focus on the molecular mechanisms and pharmacological effects of Imperatorin maybe provide potential cancer and cardiovascular protection that targets IMP. Further studies are required to elucidate the entire spectrum of cytotoxic activities of these compounds to validate and expand their preclinical and clinical applications and to clarify the potential role of IMP.

Quercetin alleviates high glucose-induced damage on human umbilical vein endothelial cells by promoting autophagy

BACKGROUND

Quercetin, a flavonoid antioxidant, has been found to exert therapeutic effects in diabetic condition. Autophagy represents a homeostatic cellular mechanism for the turnover of unfolds proteins and damaged organelles through a lysosome-dependent degradation manner. We speculated that quercetin could protect endothelial cells against high glucose-induced damage by promoting autophagic responses.

METHODS

HUVECs viability was evaluated by MTT method. Griess and TBARS assays were used to monitor the levels of NO and MDA, respectively. Intracellular ROS generation was determined in DCFDA-stained cells analyzed by flow cytometry. To investigate the role of quercetin in endothelial cell migratory behavior, we used a scratch test. The level of autophagy proteins LC3, Beclin-1 and P62 were measured by western blotting technique.

RESULTS

Our results showed that quercetin had the potential to increase cell survival after exposure to high glucose (P < 0.05). Total levels of oxidative stress markers were profoundly decreased and the activity of GSH was increased by quercetin (P < 0.05). High glucose suppressed HUVECs migration to the scratched area (P < 0.05). However, a significant stimulation in cell migration was observed after exposure to quercetin (P < 0.05). Based on data, autophagy was blocked at the late stage by high glucose concentration while quercetin enhanced autophagic response by reducing the P62 level coincided with the induction of Beclin-1 and LC3-II to LC3-I ratio (P < 0.05). All these beneficial effects were reversed by 3-methyladenine as an autophagy inhibitor.

CONCLUSION

Together, our data suggest that quercetin could protect HUVECs from high glucose induced-damage possibly by activation of the autophagy response.

Medicinal properties of Angelica archangelica root extract: Cytotoxicity in breast cancer cells and its protective effects against in vivo tumor development

OBJECTIVE

Although Angelica archangelica is a medicinal and aromatic plant with a long history of use for both medicinal and food purposes, there are no studies regarding the antineoplastic activity of its root. This study aimed to evaluate the cytotoxicity and antitumor effects of the crude extract of A. archangelica root (CEAA) on breast cancer.

METHODS

The cytotoxicity of CEAA against breast adenocarcinoma cells (4T1 and MCF-7) was evaluated by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Morphological and biochemical changes were detected by Hoechst 33342/propidium iodide (PI) and annexin V/PI staining. Cytosolic calcium mobilization was evaluated in cells staining with FURA-4NW. Immunoblotting was used to determine the effect of CEAA on anti- and pro-apoptotic proteins (Bcl-2 and Bax, respectively). The 4T1 cell-challenged mice were used for in vivo assay.

RESULTS

Using ultra-high-performance liquid chromatography-mass spectrometry analysis, angelicin, a constituent of the roots and leaves of A. archangelica, was found to be the major constituent of the CEAA evaluated in this study (73 µg/mL). The CEAA was cytotoxic for both breast cancer cell lines studied but not for human fibroblasts. Treatment of 4T1 cells with the CEAA increased Bax protein levels accompanied by decreased Bcl-2 expression, in the presence of cleaved caspase-3 and cytosolic calcium mobilization, suggesting mitochondrial involvement in breast cancer cell death induced by the CEAA in this cell line. No changes on the Bcl-2/Bax ratio were observed in CEAA-treated MCF7 cells. Gavage administration of the CEAA (500 mg/kg) to 4T1 cell-challenged mice significantly decreased tumor growth when compared with untreated animals.

CONCLUSION

Altogether, our data show the antitumor potential of the CEAA against breast cancer cells in vitro and in vivo. Further research is necessary to better elucidate the pharmacological application of the CEAA in breast cancer therapy.

Selenopheno[2,3-f]coumarins: novel scaffolds with antimetastatic activity against melanoma and breast cancer

The general aim of the current research is to find novel non-toxic small molecules with antimetastatic activity.

Preparation, Characterization, and Pharmacokinetic Evaluation of Imperatorin Lipid Microspheres and Their Effect on the Proliferation of MDA-MB-231 Cells

Imperatorin is a chemical compound belonging to the linear furanocoumarins. Imperatorin is attracting considerable attention because of its antitumor, antibacterial, anti-inflammatory, and anticoagulant activities, inhibition of myocardial hypertrophy, and other pharmacological efficacies. However, imperatorin has limited water solubility and has better lipid solubility; thus, we decided to design and synthesize imperatorin lipid microspheres to optimize the preparation conditions. The aim was to develop and formulate imperatorin lipid microspheres through nanoemulsion technology and apply the response surface⁻central composite design to optimize the imperatorin lipid microsphere formulation. The influence of the amounts of egg lecithin, poloxamer 188, and soybean oil for injection on the total percentage of the oil phase was investigated. The integrated effect of dependent variables, including particle size, polydispersity index, zeta potentials, drug loading, and encapsulation efficiency, was investigated. Data of overall desirabilities were fitted to a second-order polynomial equation, through which three-dimensional response surface graphs were described. Optimum experimental conditions were calculated by Design-Expert 8.06. Results indicated that the optimum preparation conditions were as follows: 1.39 g of egg lecithin, 0.21 g of poloxamer 188, and 10.57% soybean oil for injection. Preparation of imperatorin lipid microspheres according to the optimum experimental conditions resulted in an overall desirability of 0.7286, with the particle size of 168 ± 0.54 nm, polydispersity index (PDI) of 0.138 ± 0.02, zeta potentials of -43.5 ± 0.5 mV, drug loading of 0.833 ± 0.27 mg·mL^-1, and encapsulation efficiency of 90 ± 1.27%. The difference between the observed and predicted values of the overall desirability of the optimum formulation was in the range from 2.4% to 4.3%. Subsequently, scanning electron microscopy was used to observe the micromorphology of the imperatorin lipid microspheres, showing round globules of relatively uniform shape and sizes within 200 nm. The effect of imperatorin lipid microspheres on MDA-MB-231 proliferation was investigated by the MTT method. Furthermore, pharmacokinetics in Sprague-Dawley rats was evaluated using orbital bleeding. A sensitive and reliable liquid chromatography with the high-performance liquid chromatography (HPLC) method was established and validated for the quantification of imperatorin in rat plasma samples. The data were calculated by DAS (drug and statistics) Pharmacokinetic Software version 3.3.0 (Version 3.3.0, Shanghai, China). Results demonstrated that imperatorin lipid microspheres can significantly enhance the bioavailability of imperatorin and can significantly inhibit MDA-MB-231 cell proliferation. In conclusion, our results suggested that the response surface⁻central composite design is suitable for achieving an optimized lipid microsphere formulation. Imperatorin lipid microspheres can improve the bioavailability of imperatorin and better inhibit the proliferation of MDA-MB-231 cells as compared to imperatorin alone.

Rosmarinic acid and siRNA combined therapy represses Hsp27 (HSPB1) expression and induces apoptosis in human glioma cells

High expression of Hsp27 in glioma cells has been closely associated with tumor cell proliferation and apoptosis inhibition. The aim of the present study was to asses the effects of rosmarinic acid (RA) on Hsp27 expression and apoptosis in non-transfected and transfected human U-87 MG cells. The effect of rosmarinic acid was compared to quercetin, which is known to be a good Hsp27 inhibitor. In order to block the expression of Hsp27 gene (HSPB1), transfection with specific siRNAs was performed. Western blotting technique was used to assess the Hsp27 expression, and caspase-3 colorimetric activity assay was performed to determine apoptosis induction. According to the results, it was found that RA and quercetin effectively silenced Hsp27 and both agents induced apoptosis by activating the caspase-3 pathway. Eighty and 215 μM RA decreased the level of Hsp27 by 28.8 and 46.7% and induced apoptosis by 30 and 54%, respectively. For the first time, we reported that rosmarinic acid has the ability to trigger caspase-3 induced apoptosis in human glioma cells. As a result of siRNA transfection, the Hsp27 gene was silenced by ~ 50% but did not cause a statistically significant change in caspase-3 activation. It was also observed that apoptosis was induced at a higher level as a result of Hsp27 siRNA and subsequent quercetin or RA treatment. siRNA transfection and 215 μM RA treatment suppressed Hsp27 expression level by 90.5% and increased caspase-3 activity by 58%. Herein, we demonstrated that RA administered with siRNA seems to be a potent combination for glioblastoma therapy.

Thymoquinone synergistically potentiates temozolomide cytotoxicity through the inhibition of autophagy in U87MG cell line

OBJECTIVES

Glioblastoma multiforme (GBM) is one of the most lethal forms of human cancer and temozolomide (TMZ) is currently part of the standard treatment for this disease. Combination therapy using natural substances can enhance the anti-cancer activity of TMZ. The purpose of this study was to evaluate the effect of TMZ in combination with thymoquinone (TQ) on human GBM cell line (U87MG).

MATERIALS AND METHODS

The cell line was treated with TMZ and/or TQ. Cell viability was assessed using trypan blue and MTT assay. The effect of TMZ and/or TQ on colony-forming ability of the cells was investigated. Apoptosis and autophagy were quantified by fluorescent dye staining. The expression level of two autophagy related genes (ATG) were assessed using RT-PCR. Furthermore, nitric oxide (NO) production was detected by Griess reaction.

RESULTS

After treatment with TMZ and/or TQ, the cell viability was reduced in a time- and dose-dependent manner, and the cell survival fraction (SF) was significantly decreased (P=0.000). Apoptosis index of U87MG cells was also significantly increased (P=0.000). Autophagy was significantly increased by TMZ (P=0.000) and decreased by TQ (P=0.018). Also TMZ and/or TQ significantly decreased NO production by U87MG cell (P=0.000).

CONCLUSION

TQ enhanced the anti-cancer activity of TMZ by inhibition of autophagy at the transcriptional level and decreased the colony-forming ability and NO production of U87MG cell line.

Imperatorin-pharmacological meaning and analytical clues: profound investigation

Imperatorin, a furanocoumarin derivative, has many documented pharmacological properties which make it a candidate for possible drug development. In this review, the activity on the central nervous system, the anticancer and antiviral properties and the influence on the cardiovascular system are described. The aim of this review is also to present an overview of the techniques used for the analysis, isolation, and separation of imperatorin from plant material from the practical perspective.

Combination of Quercetin and 2-Methoxyestradiol Enhances Inhibition of Human Prostate Cancer LNCaP and PC-3 Cells Xenograft Tumor Growth

Quercetin and 2-Methoxyestradiol (2-ME) are promising anti-cancer substances. Our previous in vitro study showed that quercetin synergized with 2-Methoxyestradiol exhibiting increased antiproliferative and proapoptotic activity in both androgen-dependent LNCaP and androgen-independent PC-3 human prostate cancer cell lines. In the present study, we determined whether their combination could inhibit LNCaP and PC-3 xenograft tumor growth in vivo and explored the underlying mechanism. Human prostate cancer LNCaP and PC-3 cells were inoculated subcutaneously in male BALB/c nude mice. When xenograft tumors reached about 100 mm³, mice were randomly allocated to vehicle control, quercetin or 2-Methoxyestradiol singly treated and combination treatment groups. After therapeutic intervention for 4 weeks, combination treatment of quercetin and 2-ME i) significantly inhibited prostate cancer xenograft tumor growth by 46.8% for LNCaP and 51.3% for PC-3 as compared to vehicle control group, more effective than quercetin (28.4% for LNCaP, 24.8% for PC3) or 2-ME (32.1% for LNCaP, 28.9% for PC3) alone; ii) was well tolerated by BALB/c mice and no obvious toxic reactions were observed; iii) led to higher Bax/Bcl-2 ratio, cleaved caspase-3 protein expression and apoptosis rate; and iv) resulted in lower phosphorylated AKT (pAKT) protein level, vascular endothelial growth factor protein and mRNA expression, microvascular density and proliferation rate than single drug treatment. These effects were more remarkable compared to vehicle group. Therefore, combination of quercetin and 2-ME can serve as a novel clinical treatment regimen owning the potential of enhancing antitumor effect on prostate cancer in vivo and lessening the dose and side effects of either quercetin or 2-ME alone. These in vivo results will lay a further solid basis for subsequent researches on this novel therapeutic regimen in human prostate cancer.

Isoquercitrin inhibits the progression of pancreatic cancer in vivo and in vitro by regulating opioid receptors and the mitogen-activated protein kinase signalling pathway

Pancreatic cancer is a common malignant tumour that affects individuals worldwide. In recent years, the incidence and mortality rates of pancreatic cancer have continuously increased. Currently, the primary clinical treatment methods for pancreatic cancer include surgical resection, chemotherapy and radiotherapy. However, these treatment methods rarely produce satisfactory therapeutic outcomes. Extensive research has also proven that the effective components of several traditional Chinese medicines, particularly flavonoids extracted from plants, have significant antitumour effects. Isoquercitrin, which is one of the flavonoids found in Bidens pilosa extracts, has a significant antitumour effect. However, the antitumour effect of isoquercitrin and its mechanism of action remain unclear. The objective of the present study was to investigate the effect of isoquercitrin on the progression of pancreatic cancer and to further understand the biological characteristics of the participation of isoquercitrin in the progression of pancreatic cancer. In vitro, we found that a therapeutic dose of isoquercitrin significantly inhibited proliferation, promoted apoptosis and induced cell cycle arrest within the G1 phase in pancreatic cancer cells. Isoquercitrin activated caspase-3, -8 and -9 and reduced the mitochondrial membrane potential. In addition, isoquercitrin inhibited the expression level of the δ opioid receptor; however, isoquercitrin had no effect on the κ and µ opioid receptors. Furthermore, isoquercitrin inhibited extracellular signal-regulated kinase (ERK) phosphorylation and promoted c-Jun N-terminal kinase (JNK) phosphorylation. In vivo, we found that a therapeutic dose of isoquercitrin significantly inhibited xenograft growth in nude mice. In summary, the present study demonstrated that isoquercitrin inhibits human pancreatic cancer progression in vivo and in vitro and that its molecular mechanism may be closely related to opioid receptors and to the activation of the mitogen-activated protein kinase (MAPK) signalling pathway.

Quercetin alleviates high glucose-induced Schwann cell damage by autophagy

Quercetin can reverse high glucose-induced inhibition of neural cell proliferation, and therefore may have a neuroprotective effect in diabetic peripheral neuropathy. It is difficult to obtain primary Schwann cells and RSC96 cells could replace primary Schwann cells in studies of the role of autophagy in the mechanism underlying diabetic peripheral neuropathy. Here, we show that under high glucose conditions, there are fewer autophagosomes in immortalized rat RSC96 cells and primary rat Schwann cells than under control conditions, the proliferative activity of both cell types is significantly impaired, and the expression of Beclin-1 and LC3, the molecular markers for autophagy, is significantly lower. After intervention with quercetin, the autophagic and proliferative activity of both cell types is rescued. These results suggest that quercetin can alleviate high glucose-induced damage to Schwann cells by autophagy.