Berberine modulates expression of mdr1 gene product and the responses of digestive track cancer cells to Paclitaxel

A review on phytochemicals as combating weapon for multidrug resistance in cancer

One can recognize multidrug resistance (MDR) and residue as a biggest difficulty in cancer specialist. Chemotherapy-resistant cancer may be successfully treated by combining MDR-reversing phytochemicals with anticancer drugs. Though, clinical application of phytochemicals either alone or in conjunction with chemotherapy is still in its early stages or requires more research to determine their safety and efficacy. In this review we highlighted topics related to MDR in cancer, including an introduction to subject, mechanism of action of efflux pump, specific proteins involved in drug resistance, altered drug targets, increased drug metabolism, and potential role of phytochemicals in overcoming drug resistance.

Medicinal plants as a potential resource for the discovery of novel structures towards cancer drug resistance treatment

Despite extensive research in chemotherapy, global cancer concerns persist, exacerbated by the challenge of drug resistance, which imposes economic and medical burdens. Natural compounds, particularly secondary metabolites from medicinal plants, present promising avenues for overcoming cancer drug resistance due to their diverse structures and essential pharmacological effects. This review provides a comprehensive exploration of cancer cell resistance mechanisms and target actions for reversing resistance and highlights the in vitro and in vivo efficacy of noteworthy alkaloids, flavonoids, and other compounds, emphasizing their potential as therapeutic agents. The molecular properties supporting ligand interactions are thoroughly examined, providing a robust theoretical foundation. The review concludes by discussing methods including quantitative structure-activity relationships and molecular docking, offering insights into screening potential candidates. Current trends in clinical treatment, contributing to a holistic understanding of the multifaceted approaches to address cancer drug resistance are also outlined.

Current and emerging therapeutic approaches for colorectal cancer: A comprehensive review

Colorectal cancer (CRC) affects 1 in 23 males and 1 in 25 females, making it the third most common cancer. With roughly 608000 deaths worldwide, CRC accounts for 8% of all cancer-related deaths, making it the second most common cause of death due to cancer. Standard and conventional CRC treatments include surgical expurgation for resectable CRC and radiotherapy, chemotherapy, immunotherapy, and their combinational regimen for non-resectable CRC. Despite these tactics, nearly half of patients develop incurable recurring CRC. Cancer cells resist the effects of chemotherapeutic drugs in a variety of ways, including drug inactivation, drug influx and efflux modifications, and ATP-binding cassette transporter overexpression. These constraints necessitate the development of new target-specific therapeutic strategies. Emerging therapeutic approaches, such as targeted immune boosting therapies, non-coding RNA-based therapies, probiotics, natural products, oncolytic viral therapies, and biomarker-driven therapies, have shown promising results in preclinical and clinical studies. We tethered the entire evolutionary trends in the development of CRC treatments in this review and discussed the potential of new therapies and how they might be used in conjunction with conventional treatments as well as their advantages and drawbacks as future medicines.

Berberine for gastric cancer prevention and treatment: Multi-step actions on the Correa's cascade underlie its therapeutic effects

Gastric carcinoma (GC) is a complex multifactorial disease occurring as sequential events commonly referred to as the Correa's cascade, a stepwise progression from non-active or chronic active gastritis, to gastric precancerous lesions, and finally, adenocarcinoma. Therefore, the identification of novel agents with multi-step actions on the Correa's cascade and those functioning as multiple phenotypic regulators are the future direction for drug discovery. Recently, berberine (BBR) has gained traction owing to its pharmacological properties, including anti-inflammatory, anti-cancer, anti-ulcer, antibacterial, and immunopotentiation activities. In this article, we investigated and summarized the multi-step actions of BBR on Correa's cascade and its underlying regulatory mechanism in gastric carcinogenesis for the first time, along with a discussion on the strength of BBR to prevent and treat GC. BBR was found to suppress H. pylori infection, control mucosal inflammation, and promote ulcer healing. In the gastric precancerous lesion phase, BBR could reverse mucosal atrophy and prevent lesions in intestinal metaplasia and dysplasia by regulating inflammatory cytokines, promoting cell apoptosis, regulating macrophage polarization, and regulating autophagy. Additionally, the therapeutic action of BBR on GC was partly realized through the inhibition of cell proliferation, migration, and angiogenesis; induction of apoptosis and autophagy, and enhancement of chemotherapeutic drug sensitivity. BBR exerted multi-step actions on the Correa's cascade, thereby halting and even reversing gastric carcinogenesis in some cases. Thus, BBR could be used to prevent and treat GC. In conclusion, the therapeutic strategy underlying BBR's multi-step action in the trilogy of Correa's cascade may include "prevention of gastric mucosal inflammation (Phase 1); reversal of gastric precancerous lesions (Phase 2), and rescue of GC (Phase 3)". The NF-κB, PI3K/Akt, and MAPK signaling pathways may be the key signaling transduction pathways underlying the treatment of gastric carcinogenesis using BBR. The advantage of BBR over conventional drugs is its multifaceted and long-term effects. This review is expected to provide preclinical evidence for using BBR to prevent gastric carcinogenesis and treat gastric cancer.

The natural product berberine synergizes with osimertinib preferentially against MET-amplified osimertinib-resistant lung cancer via direct MET inhibition

Berberine is a natural product that has long been used in traditional Chinese medicine due to its antimicrobial, anti-inflammatory and metabolism-regulatory properties. Osimertinib is the first third-generation EGFR-tyrosine kinase inhibitor (TKI) approved for the treatment of non-small cell lung cancer (NSCLC) with activating EGFR mutations and those resistant to earlier generation EGFR-TKIs due to a T790M mutation. However, emergence of acquired resistance to osimertinib limits its long-term efficacy in the clinic. One known mechanism of acquired resistance to osimertinib and other EGFR-TKIs is MET (c-MET) gene amplification. Here, we report that berberine, when combined with osimertinib, synergistically and selectively decreased the survival of several MET-amplified osimertinib-resistant EGFR mutant NSCLC cell lines with enhanced induction of apoptosis likely through Bim elevation and Mcl-1 reduction. Importantly, this combination effectively enhanced suppressive effect on the growth of MET-amplified osimertinib-resistant xenografts in nude mice and was well tolerated. Molecular modeling showed that berberine was able to bind to the kinase domain of non-phosphorylated MET, occupy the front of the binding pocket, and interact with the activation loop, in a similar way as other known MET inhibitors do. MET kinase assay showed clear concentration-dependent inhibitory effects of berberine against MET activity, confirming its kinase inhibitory activity. These findings collectively suggest that berberine can act as a naturally-existing MET inhibitor to synergize with osimertinib in overcoming osimertinib acquired resistance caused by MET amplification.

Berberine Reverses Breast Cancer Multidrug Resistance Based on Fluorescence Pharmacokinetics In Vitro and In Vivo

Exploring the mechanism through which berberine (Ber) reverses the multidrug resistance (MDR) of breast cancer is of great importance. Herein, we used the methyl thiazolyl tetrazolium assay to determine the drug resistance and cytotoxicity of Ber and doxorubicin (DOX) alone or in combination on the breast cancer cell line MCF-7/DOXFluc. The results showed that Ber could synergistically enhance the inhibitory effect of DOX on tumor cell proliferation in vitro, and the optimal combination ratio was Ber/DOX = 2:1. Using a luciferase reporter assay system combined with the bioluminescence imaging technology, the efflux kinetics of d-luciferin potassium salt in MCF-7/DOXFluc cells treated with Ber in vivo was investigated. The results showed that Ber could significantly reduce the efflux of d-luciferin potassium salt in MCF-7/DOXFluc cells. In addition, western blot and immunohistochemistry experiments showed that the expression of P-glycoprotein (P-gp/ABCB1) and multidrug resistance protein 1 (MRP1/ABCC1) in MCF-7/DOXFluc cells was downregulated upon Ber treatment. Finally, high-performance liquid chromatography was used to investigate the effect of Ber on DOX tissue distribution in vivo, and the results showed that the uptake of DOX in tumor tissues increased significantly when combined with Ber (P < 0.05). Thus, the results illustrated that Ber can reverse MDR by inhibiting the efflux function of ATP-binding cassette transporters and downregulating their expression levels.

Therapeutic strategies to overcome taxane resistance in cancer

One of the primary causes of attenuated or loss of efficacy of cancer chemotherapy is the emergence of multidrug resistance (MDR). Numerous studies have been published regarding potential approaches to reverse resistance to taxanes, including paclitaxel (PTX) and docetaxel, which represent one of the most important classes of anticancer drugs. Since 1984, following the FDA approval of paclitaxel for the treatment of advanced ovarian carcinoma, taxanes have been extensively used as drugs that target tumor microtubules. Taxanes, have been shown to affect an array of oncogenic signaling pathways and have potent cytotoxic efficacy. However, the clinical success of these drugs has been restricted by the emergence of cancer cell resistance, primarily caused by the overexpression of MDR efflux transporters or by microtubule alterations. In vitro and in vivo studies indicate that the mechanisms underlying the resistance to PTX and docetaxel are primarily due to alterations in α-tubulin and β-tubulin. Moreover, resistance to PTX and docetaxel results from: 1) alterations in microtubule-protein interactions, including microtubule-associated protein 4, stathmin, centriole, cilia, spindle-associated protein, and kinesins; 2) alterations in the expression and activity of multidrug efflux transporters of the ABC superfamily including P-glycoprotein (P-gp/ABCB1); 3) overexpression of anti-apoptotic proteins or inhibition of apoptotic proteins and tumor-suppressor proteins, as well as 4) modulation of signal transduction pathways associated with the activity of several cytokines, chemokines and transcription factors. In this review, we discuss the abovementioned molecular mechanisms and their role in mediating cancer chemoresistance to PTX and docetaxel. We provide a detailed analysis of both in vitro and in vivo experimental data and describe the application of these findings to therapeutic practice. The current review also discusses the efficacy of different pharmacological modulations to achieve reversal of PTX resistance. The therapeutic roles of several novel compounds, as well as herbal formulations, are also discussed. Among them, many structural derivatives had efficacy against the MDR phenotype by either suppressing MDR or increasing the cytotoxic efficacy compared to the parental drugs, or both. Natural products functioning as MDR chemosensitizers offer novel treatment strategies in patients with chemoresistant cancers by attenuating MDR and increasing chemotherapy efficacy. We broadly discuss the roles of inhibitors of P-gp and other efflux pumps, in the reversal of PTX and docetaxel resistance in cancer cells and the significance of using a nanomedicine delivery system in this context. Thus, a better understanding of the molecular mechanisms mediating the reversal of drug resistance, combined with drug efficacy and the application of target-based inhibition or specific drug delivery, could signal a new era in modern medicine that would limit the pathological consequences of MDR in cancer patients.

GSK3 modulation in acute lung injury, myocarditis and polycystic kidney disease-related aneurysm

GSK3 are involved in different physical and pathological conditions and inflammatory regulated by macrophages contribute to significant mechanism. Infection stimuli may modulate GSK3 activity and influence host cell adaption, immune cells infiltration or cytokine expressions. To further address the role of GSK3 modulation in macrophages, the signal transduction of three major organs challenged by endotoxin, virus and genetic inherited factors are briefly introduced (lung injury, myocarditis and autosomal dominant polycystic kidney disease). As a result of pro-inflammatory and anti-inflammatory functions of GSK3 in different microenvironments and stages of macrophages (M1/M2), the rational resolution should be considered by adequately GSK3.

Traditional Herbal Medicine Mediated Regulations during Head and Neck Carcinogenesis

Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent neoplasms worldwide. It is well recognized that environmental challenges such as smoking, viral infection and alcohol consumption are key factors underlying HNSCC pathogenesis. Other than major clinical interventions (e.g., surgical resection, chemical and radiotherapy) that have been routinely practiced over years, adjuvant anticancer agents from Traditional Herbal Medicine (THM) are proposed, either alone or together with conventional therapies, to be experimentally effective for improving treatment efficacy in different cancers including HNSCCs. At a cellular and molecular basis, THM extracts could modulate different malignant indices via distinct signaling pathways and provide better control in HNSCC malignancy and its clinical complications such as radiotherapy-induced xerostomia/oral mucositis. In this article, we aim to systemically review the impacts of THM in regulating HNSCC tumorous identities and its potential perspective for clinical use.

Phytochemicals: Potential Lead Molecules for MDR Reversal

Multidrug resistance (MDR) is one of the main impediments in the treatment of cancers. MDR cancer cells are resistant to multiple anticancer drugs. One of the major mechanisms of MDR is the efflux of anticancer drugs by ABC transporters. Increased activity and overexpression of these transporters are important causes of drug efflux and, therefore, resistance to cancer chemotherapy. Overcoming MDR is a fundamental prerequisite for developing an efficient treatment of cancer. To date, various types of ABC transporter inhibitors have been employed but no effective anticancer drug is available at present, which can completely overcome MDR. Phytochemicals can reverse MDR in cancer cells via affecting the expression or activity of ABC transporters, and also through exerting synergistic interactions with anticancer drugs by addressing additional molecular targets. We have listed numerous phytochemicals which can affect the expression and activity of ABC transporters in MDR cancer cell lines. Phytochemicals in the groups of flavonoids, alkaloids, terpenes, carotenoids, stilbenoids, lignans, polyketides, and curcuminoids have been examined for MDR-reversing activity. The use of MDR-reversing phytochemicals with low toxicity to human in combination with effective anticancer agents may result in successful treatment of chemotherapy-resistant cancer. In this review, we summarize and discuss published evidence for natural products with MDR modulation abilities.

Enhanced Antitumor Efficacy and Imaging Application of Photosensitizer-Formulated Paclitaxel

Paclitaxel (PTX) is a widely used anticancer drug that works by inhibiting microtubule disassembly. PTX safety was greatly enhanced by embedding it with human albumin. Here, we study the synergistic effects of PTX with photodynamic therapy (PDT) both in vitro and in vivo by constructing photosensitizer-PTX nanotheranostics (PPNTs). PPNTs were fabricated via noncovalent hydrophobic interactions and π-π stacking between an amphipathic photosensitizer and PTX with an average diameter of ∼80 nm, and these showed high stability in biological conditions. In a tumor-bearing mouse model, PPNTs were shown to accumulate at the tumor site based on three-dimensional fluorescence tomographic imaging. Under 680 nm light irradiation, PPNTs exhibited a superior solid tumor ablation effect in a mouse model, with a dose of PTX (0.2 mg/kg) that is 10-fold lower than that typically used. Mechanistically, PPNTs induced a strong apoptotic response in cells under light illumination and showed an increased antitumor efficacy that is 47.2-fold and 57.6-fold higher than that of the photosensitizer nanoparticles (PNTs) and free PTX, respectively. In addition, PPNTs showed enhanced cellular uptake with focused mitochondria and lysosome colocalization compared to that of PNTs and the amount of PTX delivered in PPNTs was sufficient to induce cell cycle arrest in the G2/M phase. These findings indicated that the current combination therapy has advantages over monotherapy in promoting tumor regression and ultimately achieving tumor elimination.

Natural Products and Synthetic Analogs as a Source of Antitumor Drugs

Cancer is a heterogeneous disease and one of the major issues of health concern, especially for the public health system globally. Nature is a source of anticancer drugs with abundant pool of diverse chemicals and pharmacologically active compounds. In recent decade, some natural products and synthetic analogs have been investigated for the cancer treatment. This article presents the utilization of natural products as a source of antitumor drugs.

A Phase I Trial of Berberine in Chinese with Ulcerative Colitis

The Chinese natural product, berberine, has biological properties that support its potential efficacy as a colon cancer prevention agent. Its longstanding use in China to treat gastrointestinal tract and rheumatologic disorders is generally regarded as safe, supporting initial investigations in an at-risk population, such as individuals with ulcerative colitis. However, the safety of berberine in this population is not established. Individuals living in China with biopsy-proven ulcerative colitis, ≤grade 2 dysplasia, and with a ulcerative colitis disease activity index (UCDAI) score ≤1 on mesalamine, were randomized 3:1 in a double-blind phase I trial to berberine 900 mg/day or placebo for 3 months, with the primary objective of assessing safety. Blood samples and biopsies of the colorectum, from prespecified locations, were collected prior to and following therapy. Secondary endpoints included changes in UCDAI score, and in tissue and plasma markers of inflammation. Of toxicities at least possibly related, one episode of grade 3 elevation in transaminases and one episode of grade 1 nausea were observed among 12 individuals on berberine, and none were observed among 4 on placebo. The mean plasma berberine concentration was 3.5 nmol/L after berberine treatment, significantly higher than 0.5 nmol/L with placebo. Berberine significantly decreased the Geboes grade in colonic tissue, but had a nonsignificant effect on other tissue or blood biomarkers related to cell growth and inflammation. The combination of berberine and mesalamine is well tolerated in Chinese with ulcerative colitis and may enhance mesalamine's anti-inflammatory effects in colonic tissue.

Application of alkaloids in reversing multidrug resistance in human cancers

Multidrug resistance (MDR) in human cancer is one of greatest challenges in cancer therapy. Natural products, especially the alkaloids, exert reversed effects on MDR with low toxicity, by interacting with various targets. In this review article, we summarize the recent progress made in the research of the main alkaloids, including classification, function, mechanism, research status, and application in reversing MDR.

Berberine Upregulates P-Glycoprotein in Human Caco-2 Cells and in an Experimental Model of Colitis in the Rat via Activation of Nrf2-Dependent Mechanisms

Downregulation of P-glycoprotein (P-gp) is implicated in the pathophysiology of inflammatory bowel disease (IBD). Berberine, a principal isoquinoline alkaloid extracted from Berberis species, has been reported to exhibit therapeutic potential in IBD. In this study, we used a dextran sulfate sodium (DSS)-induced colitis rat model to evaluate the effect of berberine on P-gp and explore its mechanism of action. Berberine treatment improved DSS-induced colitis symptoms, attenuated inflammatory markers (myeloperoxidase, tumor necrosis factor-α, and interleukin-1β and -6), and enhanced P-gp expression in a dose-dependent manner. Although colonic expression of the P-gp-related nuclear receptor pregnane X receptor and transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) were downregulated in the colitis model, gene and protein expression analysis revealed that berberine treatment reversed only the downregulation of Nrf2. In vitro studies using Caco-2 cells showed that the multidrug resistance 1 (MDR1) gene and P-gp protein were upregulated by berberine in a dose- and time-dependent manner. Significant upregulation of the MDR1 gene by berberine was abrogated by Nrf2 silencing, indicating that the Nrf2-mediated pathway was responsible for this activation. Luciferase assays showed a dose-dependent increase in Nrf2 reporter gene activity after berberine treatment in Caco-2 cells, with a significant 2-fold elevation at 2.5 μM berberine, suggesting that berberine is a strong Nrf2 activator. These results indicate the possible involvement of Nrf2-mediated upregulation of P-gp in the therapeutic effect of berberine on colitis and highlight the potential of P-gp and/or Nrf2 as new therapeutic targets for IBD.

Assessing the anticancer effects associated with food products and/or nutraceuticals using in vitro and in vivo preclinical development-related pharmacological tests

This review is part of a special issue entitled "Role of dietary pattern, foods, nutrients and nutraceuticals in supporting cancer prevention and treatment" and describes a pharmacological strategy to determine the potential contribution of food-related components as anticancer agents against established cancer. Therefore, this review does not relate to chemoprevention, which is analysed in several other reviews in the current special issue, but rather focuses on the following: i) the biological events that currently represent barriers against the treatment of certain types of cancers, primarily metastatic cancers; ii) the in vitro and in vivo pharmacological pre-clinical tests that can be used to analyse the potential anticancer effects of food-related components; and iii) several examples of food-related components with anticancer effects. This review does not represent a catalogue-based listing of food-related components with more or less anticancer activity. By contrast, this review proposes an original pharmacological strategy that researchers can use to analyse the potential anticancer activity of any food-related component-e.g., by considering the crucial characteristics of cancer biological aggressiveness. This review also highlights that cancer patients undergoing chemotherapy should restrict the use of "food complements" without supervision by a medical nutritionist. By contrast, an equilibrated diet that includes the food-related components listed herein would be beneficial for cancer patients who are not undergoing chemotherapy.

Berberine Enhances Chemosensitivity and Induces Apoptosis Through Dose-orchestrated AMPK Signaling in Breast Cancer

Breast cancer is the most common malignancy in women. Although personalized or targeting molecular cancer therapy is more popular up to now, the cytotoxicity chemotherapy for patients with advanced breast cancer is considered as the alternative option. However, chemoresistance is still the common and critical limitation for breast cancer treatment. Berberine, known as AMPK activator, has shown multiple activities including antitumor effect. In this study, we investigate the chemosensitive effect of different dosages berberine on drug-resistant human breast cancer MCF-7/MDR cell in vitro and in vivo, and the mechanisms underlying AMPK activation on Doxorubicin (DOX) chemosensitivity. Our results showed that berberine could overcome DOX resistance in dose-orchestrated manner: On one hand, low-dose berberine can enhance DOX sensitivity in drug-resistance breast cancer cells through AMPK-HIF-1α-P-gp pathway. On the other hand, high-dose berberine alone directly induces apoptosis through the AMPK-p53 pathway with the independence of HIF-1α expression. Taken together, our findings demonstrate that berberine sensitizes drug-resistant breast cancer to DOX chemotherapy and directly induces apoptosis through the dose-orchestrated AMPK signaling pathway in vitro and in vivo. Berberine appears to be a promising chemosensitizer and chemotherapeutic drug for breast cancer treatment.

Simultaneous Determination of Eight Alkaloids in Rat Plasma by UHPLC-MS/MS after Oral Administration of Coptis deltoidea C. Y. Cheng et Hsiao and Coptis chinensis Franch

A ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) method was successfully developed and validated for the identification and determination of eight alkaloids: tetrahydropalmatine (A); palmatine (B); magnoflorine (C); columbamine (D); berberine (E); worenine (F); berberrubine (G) and coptisine (H) in rat plasma, which are the active components in Coptis deltoidea C. Y. cheng et Hsiao (CCY) and Coptis chinensis Franch (CF). The chromatographic separation of analytes was successfully achieved on an Agilent SB-C₁₈ column (1.8 µm, 150 mm × 2.1 mm) using a programme with a mobile phase consisting of acetonitrile and water containing 0.3% acetic acid at a flow rate of 0.25 mL/min. The analytes were detected with a triple quadrupole tandem MS in multiple reaction monitoring (MRM) mode and an electrospray ionization (ESI) source in positive mode. The validated method showed good linearity over a wide concentration range (r² > 0.991), and lower limits of quantification (LLOQ) less than 1.1 ng/mL for all analytes, and matrix effects ranged from 85.2% to 106.8%. The mean extraction recoveries were no less than 86.4%, and the precision and accuracy were within the acceptable limits. All analytes were proven to be stable during sample storage and analysis procedures. The method validation results demonstrated that the proposed method was sensitive, specific, and reliable, which could lay a foundation for the pharmacokinetic study of eight analytes after oral administration of CCY and CF in subsequent studies.

MAPK pathways are involved in the inhibitory effect of berberine hydrochloride on gastric cancer MGC 803 cell proliferation and IL-8 secretion in vitro and in vivo

Gastric cancer is the second leading cause of cancer-associated mortality worldwide. This investigation aimed to identify whether the mitogen‑activated protein kinase (MAPK) signaling pathways are involved in the inhibitory effect of berberine hydrochloride (BER) on MGC 803 cells in vitro and in vivo. BER time‑ and dose‑dependently inhibited proliferation of MGC 803 cells. It also suppressed tumorigenesis in nude mice xenografted with MGC 803 cells. Additionally, BER reduced interleukin‑8 (IL‑8) secretion in vitro and in vivo. Further investigation demonstrated that inactivation of p38 MAPK, extracellular-signal regulated kinase 1/2 and c‑Jun N‑terminal kinase by BER contributed to the decreased proliferation and tumorigenesis, and the change in IL‑8 expression levels. However, there was no significant synergistic inhibitory effect of combined BER and evodiamine (EVO) treatment on tumorigenesis, and BER reduced the upregulation of IL‑8 induced by EVO in vivo. The results of the current study suggested that BER may be an effective and safe drug candidate for treating gastric cancer via modulation of the MAPK signaling pathways.

Lipid-modifying effects of nutraceuticals: An evidence-based approach

The present review provides an up-to-date summary of the findings on the lipid-lowering effects of the most important nutraceuticals and functional foods. Based on current knowledge, nutraceuticals might exert significant lipid-lowering, and their use has several advantages: A number of important questions remain to be addressed, including whether longer durations of therapy would result in a better response and the exact safety profile of nutraceuticals, especially at doses higher than those consumed in an average diet. Additionally, data regarding the effects of nutraceutical supplementation on the incidence of cardiovascular outcomes are lacking, and it is not clear whether additional lipid lowering by nutraceuticals can modify the residual cardiovascular risk that remains after statin therapy.

Berberine Increases Doxorubicin Sensitivity by Suppressing STAT3 in Lung Cancer

Berberine (BBR), an alkaloid component isolated from Chinese medicinal herb Huang Lian, has aroused broad interests for its antitumor effect in recent years. The signal transducer and activator of transcription 3 (STAT3), plays critical roles in malignant transformation and progression and was found to be constitutively activated in a variety of human cancers. In this study, we show that BBR inhibited cell proliferation, induced apoptosis, and suppressed tumor spheroid formation of lung cancer cell lines. These effects were correlated with BBR-mediated suppression of both phosphorylated and total levels of STAT3 protein. Furthermore, BBR promoted STAT3 degradation by enhancing ubiquitination. Importantly, we demonstrated that BBR was able to inhibit doxorubicin (DOX)-mediated STAT3 activation and sensitize lung cancer cells to the cytotoxic effect of DOX treatment. Given that BBR is widely used in clinic with low toxicity, our results are potentially important for the development of a novel combinatorial therapy with BBR and DOX in the treatment of lung cancer.

Effects of berberine on proliferation, cell cycle distribution and apoptosis of human breast cancer T47D and MCF7 cell lines

OBJECTIVES

Berberine, a naturally occurring isoquinoline alkaloid, has shown antitumor properties in some in vitro systems. But the effect of berberine on breast cancer has not yet been completely studied. In this study, we evaluated anticancer properties of berberine in comparison to doxorubicin.

MATERIALS AND METHODS

The antiproliferative effects of berberine and doxorubicin alone and in combination were evaluated in T47D and MCF7 cell lines using MTT cytotoxicity assay. In addition, flow cytometry analysis was performed to evaluate the cell cycle alteration and apoptosis induction in these cell lines following exposure to berberine and doxorubicin alone and in combination.

RESULTS

The IC50 of berberine was determined to be 25 µM after 48 hr of treatment in both cell lines but for doxorubicin it was 250 nM and 500 nM in T47D and MCF-7 cell lines, respectively. Co-treatment with berberine and doxorubicin increased cytotoxicity in T47D cells more significantly than in MCF-7 cells. Flow cytometry results demonstrated that berberine alone or in combination with doxorubicin induced G2/M arrest in the T47D cells, but G0/G1 arrest in the MCF-7 cells. Doxorubicin alone induced G2/M arrest in both cell lines. Furthermore, berberine and doxorubicin alone or in combination significantly induced apoptosis in both cell lines.

CONCLUSION

Berberine alone and in combination with doxorubicin inhibited cell proliferation, induced apoptosis and altered cell cycle distribution of breast cancer cells. Therefore, berberine showed to be a good candidate for further studies as a new anticancer drug in the treatment of human breast cancer.

Potential benefits of berberine in the management of perimenopausal syndrome

Cardiovascular diseases are one of the leading causes of morbidity and mortality in women after menopause and 56% of all causes of death in Western European countries. Nowadays, with increasing life span, women spend approximately one-third of their life-time in postmenopausal state; therefore, the development of new strategies to improve the prevention and treatment of menopause-associated pathologies is important topic in clinical practice. The studies to assess the safety of hormone replacement therapy in women with estrogen deficiency have not been conclusive due to the relative contraindications; therefore, hormone replacement therapy is prescribed only in selected cases and for a limited time. For this reason, today women are encouraged to use naturally available compounds to prevent or to attenuate menopausal symptoms and correlated pathologies, with fewer side effects. Among these compounds, berberine, an isoquinoline alkaloid derived from plants of the generis Berberis, has been recognized as being capable of decreasing oxidative stress, LDL, triglycerides, and insulin resistance and of improving the mood. This review describes the cellular and clinical effects associated with the use of berberine, which suggest that this molecule could be an effective natural supplement to ensure a smooth peri- and postmenopausal transition.

From prejudice to evidence: the case of rhizoma coptidis in singapore

Rhizoma Coptidis (RC), commonly known as huanglian, is a herb frequently used in Traditional Chinese Medicine (TCM) prescriptions. Known to have "clearing damp-heat, quenching fire and counteracting poison" properties, it was widely used in the Chinese community in Singapore. Berberine, an alkaloid isolated from RC, is known to have a wide array of therapeutic effects including antimicrobial, antineoplastic, and hepatoprotective effects. In 1978, RC was implicated in causing neonatal jaundice (NNJ) and kernicterus in neonates suffering from glucose-6-phosphate dehydrogenase (G6PD) deficiency, leading to the banning of RC and berberine in Singapore. More than three decades later, accumulating evidence-based studies pointing to the safety of RC for general public and better understanding of G6PD deficiency, the Health Sciences Authority (HSA) in Singapore reviewed and lifted the prohibition on RC and berberine, turning a brand new chapter in the history of TCM in Singapore. This paper aims to review the safety of RC and berberine, using the prohibition of use and subsequent lifting of ban on RC and berberine in Singapore as an illustration to highlight the importance of evidence-based studies in Traditional Chinese Medicine (TCM).

Transportation of berberine into HepG2, HeLa and SY5Y cells: a correlation to its anti-cancer effect

The anti-cancer activities of berberine (BBR) have been reported extensively in various cancer cell lines. However, the minimal inhibitory concentrations of BBR varied greatly among different cell lines and very few studies have been devoted to elucidate this aspect. In this study, we employed three cancer cell lines, HepG2, HeLa and SY5Y, to compare the transportation and distribution of BBR. HPLC results demonstrated that BBR was capable of penetrating all the cell lines whereas the cumulative concentrations were significantly different. HepG2 cells accumulated higher level of BBR for longer duration than the other two cell lines. Molecular docking studies revealed the BBR binding site on P-glycoprotein 1 (P-gp). In addition, we elucidated that BBR regulated P-gp at both mRNA and protein levels. BBR induced the transcription and translation of P-gp in HeLa and SY5Y cells, whereas BBR inhibited P-gp expression in HepG2 cells. Further study showed that BBR regulates P-gp expression depending on different mechanisms (or affected by different factors) in different cell lines. To summarize, our study has revealed several mechanistic aspects of BBR regulation on P-gp in different cancer cell lines and might shed some useful insights into the use of BBR in the anti-cancer drug development.

Effects of berberine in the gastrointestinal tract - a review of actions and therapeutic implications

Berberine is an isoquinoline alkaloid present in several plant species, including Coptis sp. and Berberis sp. In traditional medicine, extracts of berberine are used in the treatment of diarrhea of different origins. Recent studies have shown that berberine and its derivatives have significant biological effects on gastrointestinal (GI) and other functions and may become therapeutics for the treatment of diarrhea, gastroenteritis, diabetes, hyperlipidemia, cardiovascular diseases and inflammatory conditions. This paper summarizes the current knowledge on the actions of berberine in the GI tract. Binding and target sites, activated intracellular pathways, as well as the absorption and metabolism of berberine are discussed. Effects that may be useful in future clinical treatment, like antidiarrheal, anti-inflammatory and antitumor effects are critically reviewed and potential clinical applications are presented in detail.

Cytotoxicity enhancement in MDA-MB-231 cells by the combination treatment of tetrahydropalmatine and berberine derived from Corydalis yanhusuo W. T. Wang

Aim:

Our previous works have demonstrated that Chinese herb medicine yanhusuo (Corydalis yanhusuo W. T. Wang) has strong anti-cancer proliferation effect in MDA-MB-231 cells. The goal of this study was to find out the synergic cytotoxicity effect of three natural compounds, tetrahydropalmatine (THP), berberine (Ber), and dehydrocorydaline (DHC), isolated from C. yanhusuo W. T. Wang.

Materials and Methods:

The IC₅₀ of THP Ber and DHC in single use, as well as in combination use at fixed ratios and doses was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Isobologram, combination index and modified coefficient of drug interaction (CDI) methods were used for evaluation the combination effects of THF! Ber, and DHC in different ratio and concentration.

Results:

The results indicated that the combination of THP and Ber shown the strongest anti-cancer cell proliferation effect at the ratio of 2:3 (Ber: THF the average CDI value was 0.5795). DHC and THP have additive cytotoxicity in MDA-MB-231 cells. However, there wasn’t any synergistic effect between Ber and DHC, and it even exhibited antagonistic effect when the percentage of DHC was >50%.

Conclusion:

Our findings suggested that the combination of THP and Ber might be beneficial for anti-proliferation of MDA-MB-231 breast cancer cells through a significant synergy effect.

Berberine acts as a natural inhibitor of Wnt/β-catenin signaling--identification of more active 13-arylalkyl derivatives

Aberrant activation of the canonical Wnt/β-catenin signaling pathway has been reported for numerous tumors of different origins. In most cases, mutations in components of the Wnt signaling pathway or in β-catenin itself were detected which ultimately induce a genetic program that promotes cell proliferation and attenuates apoptosis. Thus, targeting of Wnt/β-catenin signaling is of specific therapeutic interest. Herein, we investigated the plant-derived isoquinoline alkaloid berberine, which has been reported to have anticancer activity, and synthetic 13-arylalkyl derivatives thereof for their effects on Wnt/β-catenin signaling. Berberine did not show major effects on viability of HEK-293 embryonic kidney and HCT116 colon carcinoma cells and was not toxic in concentrations up to 20 µM. Berberine inhibited β-catenin transcriptional activity and attenuated anchorage-independent growth. As a result of berberine treatment, cellular levels of active β-catenin were reduced concomitant with an increase in the expression of E-cadherin. However, in unstimulated cells, the effects on β-catenin levels were low. A screen of synthetic 13-arylalkyl berberine derivatives identified compounds exhibiting activities superior to those of the naturally occurring parent substance with more than 100-fold lower EC50 values for Wnt-repression. Thus, berberine and its synthetic derivatives represent potential therapeutic agents to inhibit Wnt/β-catenin signaling in tumorigenesis.

Berberine analogue IMB-Y53 improves glucose-lowering efficacy by averting cellular efflux especially P-glycoprotein efflux

OBJECTIVE

Cellular efflux transporters, especially P-glycoprotein (P-gp), impel berberine (BBR) out of cells, and therefore reduce bioavailability of the compound. This study was designed to overcome efflux of BBR using P-gp as a target.

MATERIALS/METHODS

Molecular docking study was done to identify BBR analogues that were with low affinity to P-gp. Flow cytometry was used to determine cellular efflux of chemicals. Pharmacokinetic study was performed in Wistar rats, following oral administration of the study compounds. The efficacies of chemicals on glucose homeostasis were determined both in cultured cells and diabetic KK-Ay and db/db mice.

RESULTS

In the molecular docking study, we found that among BBR analogues pseudo-berberine (IMB-Y53) has low affinity to P-gp. IMB-Y53 was retained in Caco-2, HL-7702 and C2C12 cells for a significantly longer period of time than BBR did. P-gp inhibitor tetrandrine (Tet) abolished the efflux of BBR at different extent depending on the expression level of P-gp; however, Tet had no impact on IMB-Y53 efflux. BBR increased P-gp expression dose-dependently in intestinal and liver cells; IMB-Y53 also up-regulated P-gp but at a much lower level as compared with BBR. Administered at equal dose in rats, the maximum plasma concentration (C(max)) and area under concentration-time curve (AUC(0-24)) of IMB-Y53 were 1.61 and 2.27-fold of those of BBR, respectively, indicating an improved bioavailability. IMB-Y53 stimulated glucose utility in cultured cells with a degree similar to that of BBR, but exhibited enhanced glucose-lowering efficacy in KK-Ay and db/db diabetic mice.

CONCLUSIONS

These results suggest that overcoming cellular efflux especially P-gp's function improves bioavailability and hypoglycemic effect of BBR.

Prevention and Treatment of Colorectal Cancer by Natural Agents From Mother Nature

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States after cancers of the lung and the breast/prostate. While the incidence of CRC in the United States is among the highest in the world (approximately 52/100,000), its incidence in countries in India is among the lowest (approximately 7/100,000), suggesting that lifestyle factors may play a role in development of the disease. Whereas obesity, excessive alcohol consumption, a high-calorie diet, and a lack of physical activity promote this cancer, evidence indicates that foods containing folates, selenium, Vitamin D, dietary fiber, garlic, milk, calcium, spices, vegetables, and fruits are protective against CRC in humans. Numerous agents from "mother nature" (also called "nutraceuticals,") that have potential to both prevent and treat CRC have been identified. The most significant discoveries relate to compounds such as cardamonin, celastrol, curcumin, deguelin, diosgenin, thymoquinone, tocotrienol, ursolic acid, and zerumbone. Unlike pharmaceutical drugs, these agents modulate multiple targets, including transcription factors, growth factors, tumor cell survival factors, inflammatory pathways, and invasion and angiogenesis linked closely to CRC. We describe the potential of these dietary agents to suppress the growth of human CRC cells in culture and to inhibit tumor growth in animal models. We also describe clinical trials in which these agents have been tested for efficacy in humans. Because of their safety and affordability, these nutraceuticals provide a novel opportunity for treatment of CRC, an "old age" disease with an "age old" solution.

Effects of berberine and hwangryunhaedok-tang on oral bioavailability and pharmacokinetics of ciprofloxacin in rats

Hwangryunhaedok-Tang (HR) and berberine-containing single herbs are used to treat bacterial infection and inflammatory diseases in eastern Asia. The combination of berberine-containing herbal medicines and ciprofloxacin can be an excellent antibacterial chemotherapy against multidrug resistance bacteria. To evaluate the pretreatment effect of berberine and HR, vehicle, berberine (25 and 50 mg/kg/day), and HR (1.4 g/kg/day) were daily administered to rats for five consecutive days. On day 6, ciprofloxacin was administered (10 mg/kg, i.v. and 20 mg/kg, p.o.) to rats. To assess cotreatment effect of berberine and ciprofloxacin, berberine (50 mg/kg) and ciprofloxacin (20 mg/kg) were coadministered by single oral gavage. Pharmacokinetic data were estimated by noncompartmental model. Compared with ciprofloxacin alone (control group), coadministration of berberine (50 mg/kg) and ciprofloxacin significantly decreased C(max) of ciprofloxacin (P < 0.05). In addition, the pretreatment of berberine (50 mg/kg/day) and HR (1.4 g/kg/day) significantly decreased C(max) and AUC(0→∞), compared with control group (P < 0.05). The oral bioavailability of ciprofloxacin was reduced by cotreatment of berberine and pretreatment of berberine and HR. Our results suggest that the expression of P-glycoprotein and organic anion and/or organic cation transporters (OAT/OCT) could take a role in reduced oral bioavailability of ciprofloxacin by berberine and HR.

P-glycoprotein and its inhibition in tumors by phytochemicals derived from Chinese herbs

P-glycoprotein belongs to the family of ATP-binding cassette (ABC) transporters. It functions in cellular detoxification, pumping a wide range of xenobiotic compounds, including anticancer drugs out of the cell. In cancerous cells, P-glycoprotein confers resistance to a broad spectrum of anticancer agents, a phenomenon termed multidrug resistance. An attractive strategy for overcoming multidrug resistance is to block the transport function of P-glycoprotein and thus increase intracellular concentrations of anticancer drugs to lethal levels. Efforts to identify P-glycoprotein inhibitors have led to numerous candidates, none of which have passed clinical trials with cancer patients due to their high toxicity. The search for naturally inhibitory products from traditional Chinese medicine may be more promising because natural products are frequently less toxic than chemically synthesized substances. In this review, we give an overview of molecular and clinical aspects of P-glycoprotein and multidrug resistance in the context of cancer as well as Chinese herbs and phytochemicals showing inhibitory activity towards P-glycoprotein.

Antidiabetic properties of berberine: from cellular pharmacology to clinical effects

Berberine is an alkaloid that is highly concentrated in the roots, rhizomes, and stem bark of various plants. It affects glucose metabolism, increasing insulin secretion, stimulating glycolysis, suppressing adipogenesis, inhibiting mitochondrial function, activating the 5' adenosine monophosphate-activated protein kinase (AMPK) pathway, and increasing glycokinase activity. Berberine also increases glucose transporter-4 (GLUT-4) and glucagon-like peptide-1 (GLP-1) levels. On GLP-1 receptor activation, adenylyl cyclase is activated, and cyclic adenosine monophosphate is generated, leading to activation of second messenger pathways and closure of adenosine triphosphate-dependent potassium channels. Increased intracellular potassium causes depolarization, and calcium influx through the voltage-dependent calcium channels occurs. This intracellular calcium increase stimulates the migration and exocytosis of the insulin granules. In glucose-consuming tissues, such as adipose, or liver or muscle cells, berberine affects both GLUT-4 and retinol-binding protein-4 in favor of glucose uptake into cells; stimulates glycolysis by AMPK activation; and has effects on the peroxisome proliferator-activated receptor γ molecular targets and on the phosphorylation of insulin receptor substrate-1, finally resulting in decreased insulin resistance. Moreover, recent studies suggest that berberine could have a direct action on carbohydrate metabolism in the intestine. The antidiabetic and insulin-sensitizing effect of berberine has also been confirmed in a few relatively small, short-term clinical trials. The tolerability is high for low dosages, with some gastrointestinal complaints appearing to be associated with use of high dosages.

Synthesis of a dual functional anti-MDR tumor agent PH II-7 with elucidations of anti-tumor effects and mechanisms

Multidrug resistance mediated by P-glycoprotein in cancer cells has been a major issue that cripples the efficacy of chemotherapy agents. Aimed for improved efficacy against resistant cancer cells, we designed and synthesized 25 oxindole derivatives based on indirubin by structure-activity relationship analysis. The most potent one was named PH II-7, which was effective against 18 cancer cell lines and 5 resistant cell lines in MTT assay. It also significantly inhibited the resistant xenograft tumor growth in mouse model. In cell cycle assay and apoptosis assay conducted with flow cytometry, PH II-7 induced S phase cell cycle arrest and apoptosis even in resistant cells. Consistently revealed by real-time PCR, it modulates the expression of genes related to the cell cycle and apoptosis in these cells, which may contributes to its efficacy against them. By side-chain modification and FITC-labeling of PH II-7, we were able to show with confocal microscopy that not only it was not pumped by P-glycoprotein, it also attenuated the efflux of Adriamycin by P-glycoprotein in MDR tumor cells. Real-time PCR and western blot analysis showed that PH II-7 down-regulated MDR1 gene via protein kinase C alpha (PKCA) pathway, with c-FOS and c-JUN as possible mediators. Taken together, PH II-7 is a dual-functional compound that features both the cytotoxicity against cancer cells and the inhibitory effect on P-gp mediated drug efflux.

Identification of proteins interacting with multidrug resistance protein in gastric cancer

AIM: To identify proteins interacting with multidrug resistance protein (MRP) in gastric cancer cells and to evaluate their effect on tumor cell drug resistance.

METHODS: Proteins interacting with MRP were identified using immunoprecipitation and mass spectrometry. Of the proteins identified, Annexin A5 was chosen to further study its role in drug resistance of gastric cancer cells. The expression of MRP and Annexin A5 protein in SGC-7901cells and drug-resistant cell line SGC-7901/DDP was evaluated by Western blot.The impact of Annexin A5 knockdown on MRP expression and drug resistance of gastric cancer cells was evaluated using siRNA interference technology.

RESULTS: In total, 14 proteins interacting with MRP were identified. The protein expression of MRP and Annexin A5 in drug-resistant cell line SGC-7901/DDP was higher than that in SGC-7901 cell line. SiRNA-mediated silencing of the Annexin A5 gene in SGC-7901/DDP cells down-regulated the expression of MRP. The expression of Annexin A5 showed no significant difference between SGC-7901 cells and SGC-7901/DDP cells transfected with Annexin A5-specific siRNA. In addition, siRNA-mediated silencing of the Annexin A5 gene significantly reduced the IC₅₀ values of cisplatin, paclitaxel and 5-Fu in gastric cancer cells, and increased cell sensitivity to these drugs by 36, 17 and 4 folds, respectively.

CONCLUSION: Annexin A5 is a MRP-interacting protein that may be related with tumor drug resistance in gastric cancer.

Dose-response of berberine on hepatic cytochromes P450 mRNA expression and activities in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine is an isoquinoline alkaloid isolated from the root and bark of plants such as goldenseal, Berberis, and Chinese goldthread. Berberine-containing crude drugs have been used as an antimicrobial remedy against gastrointestinal infections for thousands of years. It is also widely used in Asian countries for diabetes, hypertension, and hypercholesterolemia therapy.

AIM OF THE STUDY

Potential drug-drug interactions are of concern because of the wide usage of berberine. A few studies have reported interactions between berberine and cytochromes P450 (CYPs) in vitro, but little is known about whether berberine influences CYPs in vivo, especially after repeated administration. In this study, eight-week-old male C57BL/6 mice were given berberine orally (0, 10, 30, 100, 300 mg/kg, i.g., daily for 14 days), and the effect of berberine on over 20 major Cyps and related nuclear receptors in mice livers were examined at both the mRNA and enzyme activity levels.

RESULTS

In general, liver function of mice treated with various doses of berberine had no significant change, and repeated oral administration of the 3 lower doses of berberine for 14 days did not affect the expression of genes examined. However, after the highest dose of berberine (300mg/kg), Cyp3a11 and Cyp3a25 mRNA decreased 67.6 and 87.4%, respectively, whereas Cyp1a2 mRNA increased 43.2%, and enzyme activities of Cyp3a11 and Cyp2d22 decreased 67.9 and 32.4%, respectively. Cyp2a4, 2b10 and Cyp2c29 were not altered at both mRNA and enzyme activity levels.

CONCLUSIONS

If studies in mice extrapolate to humans, lower doses of berberine appear to present a low risk of producing drug-drug interactions as a result of changed Cyp enzyme activity. However, high doses of berberine may suppress Cyp activities and result in drug-drug interactions.

Inhibition of H1N1 influenza A virus growth and induction of inflammatory mediators by the isoquinoline alkaloid berberine and extracts of goldenseal (Hydrastis canadensis)

In this study we tested whether the isoquinoline alkaloid berberine can inhibit the growth of influenza A. Our experiments showed strong inhibition of the growth of H1N1 influenza A strains PR/8/34 or WS/33 in RAW 264.7 macrophage-like cells, A549 human lung epithelial-derived cells and murine bone marrow derived macrophages, but not MDCK canine kidney cells. Studies of the mechanism underlying this effect suggest that berberine acts post-translationally to inhibit virus protein trafficking/maturation which in turn inhibits virus growth. Berberine was also evaluated for its ability to inhibit production of TNF-α and PGE(2) from A/PR/8/34 infected-RAW 264.7 cells. Our studies revealed strong inhibition of production of both mediators and suggest that this effect is distinct from the anti-viral effect. Finally, we asked whether berberine-containing ethanol extracts of goldenseal also inhibit the growth of influenza A and production of inflammatory mediators. We found strong effectiveness at high concentrations, although upon dilution extracts were somewhat less effective than purified berberine. Taken together, our results suggest that berberine may indeed be useful for the treatment of infections with influenza A.

Selective regulation of multidrug resistance protein in vascular smooth muscle cells by the isoquinoline alkaloid coptisine

When the biological activites of hydrophobic drugs or xenobiotics are studied, it is important to clarify their effects on expression and function of multidrug resistance (MDR) protein. We therefore evaluated the effects of coptisine on MDR in comparison with the structurally related isoquinoline alkaloids berberine and palmatine. To achieve this, we investigated the effects of the three alkaloids on the expression and function of P-glycoprotein/MDR1, MDR1 gene products, in vascular smooth muscle cells (VSMCs). In A10 cells (a rat VSMC line), coptisine upregulated the mRNAs of Mdr1a and Mdr1b, rodent homologues of human MDR1, and these effects were completely abrogated by actinomycin D. Coptisine also induced Mdr1a/1b protein expression and enhanced the efflux of rhodamine 123 from A10 cells. In contrast, berberine and palmatine slightly upregulated the mRNAs of Mdr1a and Mdr1b, but failed to induce Mdr1a/1b protein expression or stimulate rhodamine 123 efflux. To clarify whether these effects occurred in other cells, the effects of the three alkaloids on Mdr1a/1b function were examined in 3Y1, dRLh-84 and B16 cells. Coptisine and berberine enhanced rhodamine 123 efflux in all three cell types, while palmatine inhibited it, based on the finding that palmatine efficiently activated the Mdr1a ATPase activity as a good substrate for Mdr1a. Therefore, the three isoquinoline alkaloids regulated MDR differently in cell type-specific manners. In particular, only coptisine induced Mdr1a/1b in A10 cells and stimulated rhodamine 123 efflux. Taken together, coptisine appears to exert VSMC-selective effects on Mdr1a/1b induction in contrast to berberine and palmatine.

A systematic review of the anticancer properties of berberine, a natural product from Chinese herbs

Natural products represent a rich reservoir of potential small chemical molecules exhibiting antiproliferation and anticancer properties. An example is berberine, a protoberberine alkaloid widely distributed in medical plants used in traditional Chinese prescriptions. Recent advances have shown that berberine exerts anticancer activities both in vitro and in vivo through different mechanisms. Berberine shows inhibitory effects on the proliferation and reproduction of certain tumorigenic microorganisms and viruses, such as Heliobacter pylori and hepatitis B virus. Transcriptional regulation of some oncogene and carcinogenesis-related gene expression and interaction with both DNA and RNA are also well documented. Besides, berberine is a broad spectrum enzyme inhibitor, which affects N-acetyltransferase, cyclooxygenase-2, and topoisomerase activities and gene/protein expression. These actions, together with the regulation of reactive oxygen species production, mitochondrial transmembrane potential, and nuclear factor-kappaB activation might underlie its antiproliferative and proapoptotic effects. More importantly, the suppression of tumor growth and metastasis, the beneficial application in combined medication, and the improvement of multidrug resistance both in vivo and in vitro clearly show its potential as an alternative medicine for tumor chemotherapy.

Polymorphic nucleic Acid binding of bioactive isoquinoline alkaloids and their role in cancer

Bioactive alkaloids occupy an important position in applied chemistry and play an indispensable role in medicinal chemistry. Amongst them, isoquinoline alkaloids like berberine, palmatine and coralyne of protoberberine group, sanguinarine of the benzophenanthridine group, and their derivatives represent an important class of molecules for their broad range of clinical and pharmacological utility. In view of their extensive occurrence in various plant species and significantly low toxicities, prospective development and use of these alkaloids as effective anticancer agents are matters of great current interest. This review has focused on the interaction of these alkaloids with polymorphic nucleic acid structures (B-form, A-form, Z-form, H^L-form, triple helical form, quadruplex form) and their topoisomerase inhibitory activity reported by several research groups using various biophysical techniques like spectrophotometry, spectrofluorimetry, thermal melting, circular dichroism, NMR spectroscopy, electrospray ionization mass spectroscopy, viscosity, isothermal titration calorimetry, differential scanning calorimetry, molecular modeling studies, and so forth, to elucidate their mode and mechanism of action for structure-activity relationships. The DNA binding of the planar sanguinarine and coralyne are found to be stronger and thermodynamically more favoured compared to the buckled structure of berberine and palmatine and correlate well with the intercalative mechanism of sanguinarine and coralyne and the partial intercalation by berberine and palmatine. Nucleic acid binding properties are also interpreted in relation to their anticancer activity.

Berberine and Coptidis rhizoma as novel antineoplastic agents: a review of traditional use and biomedical investigations

ETHNOPHARMACOLOGICAL RELEVANCE

Coptidis rhizoma (huanglian) and its major component, berberine, have drawn extensive attention toward their antineoplastic effects in the recent years. The antineoplastic effects are related to the Chinese Medicine (CM) properties of huanglian in treating diseases by removing damp-heat and purging fire and counteracting toxicity.

AIM OF THE REVIEW

To trace the long history of the traditional use of huanglian from folk medicines, especially from Chinese medicine, to recent pharmacological studies of huanglian and berberine, with an emphasis on their antineoplastic effects and the promise as novel antineoplastic agents.

METHODS

A total of seven databases were extensively searched for literature research. The terms and keywords for searching included huanglian, berberine, Coptis, Coptidis rhizoma, anticancer, anti-invasion, antimatastasis and mechanism. The papers including ours with studies on anticancer and mechanism, pharmacology and toxicology of huanglian and/or berberine were focused.

RESULTS

In view of traditional use, the anticancer effects of huanglian can be ascribed to its CM trait by removing damp-heat, fire and toxicity. From modern biomedical studies, anticancer effects have been demonstrated in both huanglian and berberine. The underlying molecular mechanisms involve cell-cycle arrest, apoptosis induction and anti-inflammation. Berberine is an essential anticancer compound in huanglian. In some studies, the use of huanglian was shown to be more effective and beneficial than the use of berberine alone. The presence of other protoberberine-type alkaloids in huanglian might give synergistic effects for the anticancer effects. Berberine also demonstrates effects of antiangiogenesis, anti-invasion and anti-metastasis in some cancer cell lines, however, more investigations are required to unravel the underlying mechanisms involved.

CONCLUSIONS

The modern evidences of treating cancer with huanglian and berberine have a strong linkage with traditional concept and rules of using huanglian in CM practice. As anticancer candidates with low toxicity, berberine and its altered structure, as well as huanglian and its formulae, will attract scientists to pursue the potential anticancer effects and the mechanisms by using technologies of genomics, proteomics and other advanced approaches. On the other hand, relatively few in vivo studies have been conducted on anticancer effects of huanglian and berberine. The clinical application of berberine or huanglian as novel cancer therapeutic agents requires in vivo validations and further investigations of their anticancer mechanisms.

Adrenaline induces chemoresistance in HT-29 colon adenocarcinoma cells

Psychological distress and its ensuing chronic elevation of plasma catecholamines (adrenaline and noradrenaline) lead to poor response of tumors to chemotherapy, and constitute a poor prognostic factor for survival. Colorectal cancer patients suffer from various forms of psychological stress reflected in elevated plasma catecholamines, and their cancer cells express adrenergic receptors. Our objective was to investigate whether adrenergic activation contributes to the chemoresistance of colon cancers, and to explore the signal transduction pathway involved in the activation. The mRNA expression of the ABCB1 gene (previously MDR1) in human colon carcinoma HT-29 cell line was measured after treatment with an adrenergic receptor agonist (adrenaline) and various antagonists (propranolol, prazosin, and yohimbine). The function of P-glycoprotein, the protein product of the ABCB1 gene, was assessed by rhodamine 123 (Rh123)-retention assay, and chemosensitivity was determined by evaluating the cytotoxicity of 5-fluorouracil (5-FU) on the tumor cells. Increased ABCB1 mRNA expression and P-glycoprotein function levels in HT-29 cells by adrenaline was dose-dependent. This was accompanied by promotion of Rh123 efflux, and resistance to the growth-inhibiting effect of 5-FU in the tumor cells. The alpha2-adrenergic receptor antagonist yohimbine completely abolished the induction of ABCB1 mRNA, the stimulatory effect of adrenaline on Rh123 efflux, and the growth-inhibiting effect of 5-FU. The alpha1-adrenergic receptor and beta-adrenergic receptor antagonists did not inhibit the induction of ABCB1. The stimulating effects were coupled with extracellular receptor kinase 1/2 (Erk1/2) phosphorylation, but were not associated with protein kinase A activity. We conclude that adrenaline induces multidrug resistance in colon cancer cells by upregulating ABCB1 gene expression via alpha2-adrenergic receptors, and such effects were associated with the mitogen activated protein kinase (MAPK) pathway.