Alpha-Mangostin Reverses Multidrug Resistance by Attenuating the Function of the Multidrug Resistance-Linked ABCG2 Transporter

Mangostin enhances efficacy of aminolevulinic acid-photodynamic therapy against cancer through inhibition of ABCG2 activity

BACKGROUND

Aminolevulinic acid-photodynamic therapy (ALA-PDT) is gaining attention as a potential method for treating select cancers due to its high specificity and low side effect feature. ALA enters cancer cells and accumulate as protoporphyrin IX (PpIX), which will then trigger phototoxicity following light irradiation. However, it is reported that some cancer cells have reduced efficacy of ALA-PDT due to high expression of ABCG2, a transporter involved in the PpIX efflux. In this study, we evaluated the effect of mangostin, a natural compound containing anti-tumor property, on the efficacy of ALA-PDT against cancer and the mechanism involved.

METHODS

We utilized TMK1 gastric cancer cell line, which has high ABCG2 expression, to evaluate the PpIX accumulation and phototoxicity exerted by ALA and mangostin co-addition.

RESULTS

We found that co-addition of ALA and mangostin significantly increase the phototoxicity and PpIX accumulation in TMK1 cells. We also investigated the effect of mangostin on porphyrin-heme pathway enzymes and ABCG2 and found that the addition of mangostin reduce the activity of ABCG2, reducing PpIX efflux.

CONCLUSION

These findings suggest that mangostin enhances the efficacy of ALA-PDT in cancer through inhibition of ABCG2 activity.

Isolation and Biological Evaluation of Alfa-Mangostin as Potential Therapeutic Agents against Liver Fibrosis

The increased proliferation and activation of hepatic stellate cells (HSCs) are associated with liver fibrosis development. To date, there are no FDA-approved drugs for the treatment of liver cirrhosis. Augmentation of HSCs apoptosis is one of the resolutions for liver fibrosis. In this study, we extracted α-mangostin (1,3,6-trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one) from the fruit waste components of mangosteen pericarp. The isolated α-mangostin structure was determined and characterized with nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS) and compared with those known compounds. The intracellular signaling pathway activities of α-mangostin on Transforming growth factors-beta 1 (TGF-β1) or Platelet-derived growth factor subunit B (PDGF-BB) induced HSCs activation and were analyzed via Western blot and Real-time Quantitative Polymerase Chain Reaction (Q-PCR). α-Mangostin-induced mitochondrial dysfunction and apoptosis in HSCs were measured by seahorse assay and caspase-dependent cleavage. The in vivo anti-fibrotic effect of α-mangostin was assessed by carbon tetrachloride (CCl4) treatment mouse model. The data showed that α-mangostin treatment inhibited TGF-β1-induced Smad2/3 phosphorylation and alpha-smooth muscle actin (α-SMA) expression in HSCs in a dose-dependent manner. Regarding the PDGF-BB-induced HSCs proliferation signaling pathways, α-mangostin pretreatment suppressed the phosphorylation of extracellular-signal-regulated kinase (ERK) and p38. The activation of caspase-dependent apoptosis and dysfunction of mitochondrial respiration (such as oxygen consumption rate, ATP production, and maximal respiratory capacity) were observed in α-mangostin-treated HSCs. The CCl4-induced liver fibrosis mouse model showed that the administration of α-mangostin significantly decreased the expression of the fibrosis markers (α-SMA, collagen-a2 (col1a2), desmin and matrix metalloproteinase-2 (MMP-2)) as well as attenuated hepatic collagen deposition and liver damage. In conclusion, this study demonstrates that α-mangostin attenuates the progression of liver fibrosis through inhibiting the proliferation of HSCs and triggering apoptosis signals. Thus, α-mangostin may be used as a potential novel therapeutic agent against liver fibrosis.

ABCB1 and ABCG2 Regulation at the Blood-Brain Barrier: Potential New Targets to Improve Brain Drug Delivery

The drug efflux transporters ABCB1 and ABCG2 at the blood-brain barrier limit the delivery of drugs into the brain. Strategies to overcome ABCB1/ABCG2 have been largely unsuccessful, which poses a tremendous clinical problem to successfully treat central nervous system (CNS) diseases. Understanding basic transporter biology, including intracellular regulation mechanisms that control these transporters, is critical to solving this clinical problem.In this comprehensive review, we summarize current knowledge on signaling pathways that regulate ABCB1/ABCG2 at the blood-brain barrier. In Section I, we give a historical overview on blood-brain barrier research and introduce the role that ABCB1 and ABCG2 play in this context. In Section II, we summarize the most important strategies that have been tested to overcome the ABCB1/ABCG2 efflux system at the blood-brain barrier. In Section III, the main component of this review, we provide detailed information on the signaling pathways that have been identified to control ABCB1/ABCG2 at the blood-brain barrier and their potential clinical relevance. This is followed by Section IV, where we explain the clinical implications of ABCB1/ABCG2 regulation in the context of CNS disease. Lastly, in Section V, we conclude by highlighting examples of how transporter regulation could be targeted for therapeutic purposes in the clinic. SIGNIFICANCE STATEMENT: The ABCB1/ABCG2 drug efflux system at the blood-brain barrier poses a significant problem to successful drug delivery to the brain. The article reviews signaling pathways that regulate blood-brain barrier ABCB1/ABCG2 and could potentially be targeted for therapeutic purposes.

Quinacrine and Curcumin in combination decreased the breast cancer angiogenesis by modulating ABCG2 via VEGF A

Cancer stem cells (CSCs) cause drug resistance in cancer due to its extensive drug efflux, DNA repair and self-renewal capability. ATP binding cassette subfamily G member 2 (ABCG2) efflux pump afford protection to CSCs in tumors, shielding them from the adverse effects of chemotherapy. Although the role of ABCG2 in cancer progression, invasiveness, recurrence are known but its role in metastasis and angiogenesis are not clear. Here, using in vitro (CSCs enriched side population [SP] cells), ex vivo (patient derived primary cells), in ovo (fertilized egg embryo) and in vivo (patient derived primary tissue mediated xenograft (PDX)) system, we have systematically studied the role of ABCG2 in angiogenesis and the regulation of the process by Curcumin (Cur) and Quinacrine (QC). Cur + QC inhibited the proliferation, invasion, migration and expression of representative markers of metastasis and angiogenesis. Following hypoxia, ABCG2 enriched cells released angiogenic factor vascular endothelial growth factor A (VEGF A) and induced the angiogenesis via PI3K-Akt-eNOS cascade. Cur + QC inhibited the ABCG2 expression and thus reduced the angiogenesis. Interestingly, overexpression of ABCG2 in SP cells and incubation of purified ABCG2 protein in media induced the angiogenesis but knockdown of ABCG2 decreased the vascularization. In agreement with in vitro results, ex vivo data showed similar phenomena. An induction of vascularization was noticed in PDX mice but reduction of vascularization was also observed after treatment of Cur + QC. Thus, data suggested that in hypoxia, ABCG2 enhances the production of angiogenesis factor VEGF A which in turn induced angiogenesis and Cur + QC inhibited the process by inhibiting ABCG2 in breast cancer.

Antibacterial activities of anthraquinones: structure-activity relationships and action mechanisms

With the increasing prevalence of untreatable infections caused by antibiotic-resistant bacteria, the discovery of new drugs from natural products has become a hot research topic. The antibacterial activity of anthraquinones widely distributed in traditional Chinese medicine has attracted much attention. Herein, the structure and activity relationships (SARs) of anthraquinones as bacteriostatic agents are reviewed and elucidated. The substituents of anthraquinone and its derivatives are closely related to their antibacterial activities. The stronger the polarity of anthraquinone substituents is, the more potent the antibacterial effects appear. The presence of hydroxyl groups is not necessary for the antibacterial activity of hydroxyanthraquinone derivatives. Substitution of di-isopentenyl groups can improve the antibacterial activity of anthraquinone derivatives. The rigid plane structure of anthraquinone lowers its water solubility and results in the reduced activity. Meanwhile, the antibacterial mechanisms of anthraquinone and its analogs are explored, mainly including biofilm formation inhibition, destruction of the cell wall, endotoxin inhibition, inhibition of nucleic acid and protein synthesis, and blockage of energy metabolism and other substances.

Drug resistance of hepatoma cells induced by ATP‑binding cassette transporter G2 by reducing intracellular drug concentration

The side effects and drug resistance during chemotherapy seriously affect the outcome of and may lead to the failure of chemotherapy for patients with hepatoma. The aim of the present study was to investigate the association between the expression of ATP-binding cassette transporter G2 (ABCG2) in hepatoma cells and the drug resistance of hepatoma. An MTT assay was used to determine the half-maximal inhibitory concentration (IC₅₀) of Adriamycin (ADM) in hepatoma HepG2 cells after treatment with ADM for 24 h. An ADM-resistant hepatoma cell subline, HepG2/ADM, was generated from the HepG2 hepatoma cell line through a stepwise selection with ADM doses from 0.01 to 0.1 µg/ml. The HepG2/ABCG2 cell line, an ABCG2-overexpressing hepatoma cell line, was established by transfecting the ABCG2 gene into HepG2 cells. The MTT assay was then used to detect the IC₅₀ of ADM in HepG2/ADM and HepG2/ABCG2 cells after treatment with ADM for 24 h and the resistance index was calculated. The apoptosis, cell cycle and ABCG2 protein expression levels in HepG2/ADM, HepG2/ABCG2 cells, HepG2/PCDNA3.1 and their parental HepG2 cells were detected by flow cytometry. In addition, flow cytometry was used to detect the efflux effect of HepG2/ADM and HepG2/ABCG2 cells after ADM treatment. ABCG2 mRNA expression in cells was detected by reverse transcription-quantitative PCR. After 3 months of ADM treatment, HepG2/ADM cells grew stably in the cell culture medium containing 0.1 µg/ml ADM and the cells were named HepG2/ADM cells. ABCG2 was overexpressed in HepG2/ABCG2 cells. The IC₅₀ of ADM in HepG2, HepG2/PCDNA3.1, HepG2/ADM and HepG2/ABCG2 cells was 0.72±0.03, 0.74±0.01, 11.17±0.59 and 12.75±0.47 µg/ml, respectively. The cell apoptotic rate of HepG2/ADM and HepG2/ABCG2 cells was not significantly different compared with that of HepG2 and HepG2/PCDNA3.1 cells (P>0.05), but the G₀/G₁ phase population of the cell cycle decreased and the proliferation index increased significantly (P<0.05). The expression levels of ABCG2 gene and protein in HepG2/ADM and HepG2/ABCG2 cells were significantly higher than those in HepG2 and HepG2/PCDNA3.1 cells (P<0.01), but there was no significant difference between HepG2 and HepG2/PCDNA3.1 cells (P>0.05). The ADM efflux effect of HepG2/ADM and HepG2/ABCG2 cells was significantly higher than that of parental HepG2 and HepG2/PCDNA3.1 cells (P<0.05). Therefore, the present study demonstrated that ABCG2 expression is highly increased in drug-resistant hepatoma cells and that high expression of ABCG2 is involved in the drug resistance of hepatoma by reducing the intracellular drug concentration.

Novel Epoxides of Soloxolone Methyl: An Effect of the Formation of Oxirane Ring and Stereoisomerism on Cytotoxic Profile, Anti-Metastatic and Anti-Inflammatory Activities In Vitro and In Vivo

It is known that epoxide-bearing compounds display pronounced pharmacological activities, and the epoxidation of natural metabolites can be a promising strategy to improve their bioactivity. Here, we report the design, synthesis and evaluation of biological properties of αO-SM and βO-SM, novel epoxides of soloxolone methyl (SM), a cyanoenone-bearing derivative of 18βH-glycyrrhetinic acid. We demonstrated that the replacement of a double-bound within the cyanoenone pharmacophore group of SM with α- and β-epoxide moieties did not abrogate the high antitumor and anti-inflammatory potentials of the triterpenoid. It was found that novel SM epoxides induced the death of tumor cells at low micromolar concentrations (IC₅₀^(24h) = 0.7–4.1 µM) via the induction of mitochondrial-mediated apoptosis, reinforced intracellular accumulation of doxorubicin in B16 melanoma cells, probably by direct interaction with key drug efflux pumps (P-glycoprotein, MRP1, MXR1), and the suppressed pro-metastatic phenotype of B16 cells, effectively inhibiting their metastasis in a murine model. Moreover, αO-SM and βO-SM hampered macrophage functionality in vitro (motility, NO production) and significantly suppressed carrageenan-induced peritonitis in vivo. Furthermore, the effect of the stereoisomerism of SM epoxides on the mentioned bioactivities and toxic profiles of these compounds in vivo were evaluated. Considering the comparable antitumor and anti-inflammatory effects of SM epoxides with SM and reference drugs (dacarbazine, dexamethasone), αO-SM and βO-SM can be considered novel promising antitumor and anti-inflammatory drug candidates.

Nanozyme-natural enzymes cascade catalyze cholesterol consumption and reverse cancer multidrug resistance

Multidrug resistance is still a major obstacle to cancer treatment. The most studies are to inhibit the activity of the drug transporter P-glycoprotein (P-gp), but the effect is not ideal. Herein, a nanosystem was built based on cascade catalytic consumption of cholesterol. Cholesterol oxidase (natural enzyme, COD) was immobilized on the carrier (NH₂-MIL-88B, MOF) through amide reaction, COD catalyzed the consumption of cholesterol, the reaction product H₂O₂ was further produced by the MOF with its peroxidase-like activity to produce hydroxyl radicals (•OH) with killing effect. Due to the high expression of CD44 receptor on the surface of tumor cells, we encapsulated chondroitin sulfate gel shell (CS-shell) with CD44 targeting and apoptosis promoting effect on the surface of DOX@MOF-COD nanoparticles, which can accurately and efficiently deliver the drugs to the tumor site and improve the effect of reversing drug resistance. Taking drug-resistant cell membrane as "breakthrough", this paper will provide a new idea for reversing multidrug resistance of tumor.

α-Mangostin Nanoparticles Cytotoxicity and Cell Death Modalities in Breast Cancer Cell Lines

α-Mangostin (AMG) is a potent anticancer xanthone that was discovered in mangosteen (Garcinia mangostana Linn.). AMG possesses the highest opportunity for chemopreventive and chemotherapeutic therapy. AMG inhibits every step in the process of carcinogenesis. AMG suppressed multiple breast cancer (BC) cell proliferation and apoptosis by decreasing the creation of cancerous compounds. Accumulating BC abnormalities and their associated molecular signaling pathways promotes novel treatment strategies. Chemotherapy is a commonly used treatment; due to the possibility of unpleasant side effects and multidrug resistance, there has been substantial progress in searching for alternative solutions, including the use of plant-derived natural chemicals. Due to the limitations of conventional cancer therapy, nanotechnology provides hope for effective and efficient cancer diagnosis and treatment. Nanotechnology enables the delivery of nanoparticles and increased solubility of drugs and drug targeting, resulting in increased cytotoxicity and cell death during BC treatment. This review summarizes the progress and development of AMG’s cytotoxicity and the mechanism of death BC cells. The combination of natural medicine and nanotechnology into a synergistic capital will provide various benefits. This information will aid in the development of AMG nanoparticle preparations and may open up new avenues for discovering an effective BC treatment.

Predictors of therapeutic efficacy of 5-aminolevulinic acid-based photodynamic therapy in human prostate cancer

BACKGROUND

Photodynamic therapy (PDT) is a minimally invasive cancer therapy. However, its therapeutic efficacy for prostate cancer is not yet fully understood. In this study, the predictors of therapeutic efficacy of 5-aminolevulinic acid-based PDT (ALA-PDT) on prostate cancer cells are investigated.

MATERIALS AND METHODS

The human prostate cancer cell lines, PC-3, 22Rv1, DU145, and LNCap were used to investigate the effects of ALA-PDT on protoporphyrin IX (PpIX) intracellular accumulation, which was measured by flow cytometry. The cytotoxicity of ALA-PDT was evaluated by MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay. The levels of porphyrin metabolism-related enzyme and transporter mRNA were comprehensively evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Protein expression was evaluated by Western blot. A xenograft model was created using PC-3 and 22Rv1, and then, pathological analysis was performed to determine the therapeutic effect of ALA-PDT RESULTS: PC-3 and LNCap cells showed high accumulation of PpIX and high sensitivity to ALA-PDT, while 22Rv1 and DU145 showed low accumulation of PpIX and low sensitivity to ALA-PDT. ALA-PDT-induced cytotoxicity correlated negatively with PpIX accumulation. The in vitro assays identified the ATP-binding cassette transporter subfamily G2 (ABCG2) transporter dimer as a predictor of treatment response. In vivo immunohistochemical staining of ABCG2 transporter showed low expression in PC-3 cells and high expression in 22Rv1 cells, and ALA-PDT-induced tumor tissue degeneration was greater in PC-3 cells than in 22Rv1 cells.

CONCLUSION

The ABCG2 transporter is a useful predictor of the therapeutic effect of ALA-PDT on human prostate cancer cells.

Cytotoxic and Antiproliferative Effects of β-Mangostin on Rat C6 Glioma Cells Depend on Oxidative Stress Induction via PI3K/AKT/mTOR Pathway Inhibition

Background

Glioma is the most common malignant tumor of the nervous system, which accounts for more than 45% of central nervous system tumors and seriously threatens our health. Because of high mortality rate, limitations, and many complications of traditional treatment methods, new treatment methods are urgently needed. β-Mangostin is a natural compound derived from the fruit of Garcinia mangostana L. and it has anticancer activity in several types of cancer cells. However, the antitumor effect of β-mangostin in glioma has not been clarified. Hence, this study aimed to investigate its therapeutic effects on gliomas.

Materials and Methods

To study the effect of β-mangostin on glioma cells, cell viability assay, reactive oxygen species production, cell cycle, apoptosis, and mitochondrial membrane potential were evaluated in the C6 cell line in vitro. Immunofluorescence and Western blotting were used to analyze protein expression and phosphorylation to study its mechanism of action. A subcutaneous xenograft model was used to investigate the effect of β-mangostin on tumorigenesis in vivo.

Results

We found that β-mangostin can inhibit glioma cell growth and induce oxidative damage in vitro. In addition, it reduces the phosphorylated form levels of PI3K, AKT and mTOR. Furthermore, the phosphorylated form levels of PI3K, AKT and mTOR were increased after the PI3K inhibitor was added. In vivo experiments showed that β-mangostin can inhibit tumor growth as shown by its reduced size and weight.

Conclusion

This study suggests that β-mangostin can inhibit cell proliferation and induce oxidative damage in cells. It is the first study to demonstrate that β-mangostin induces oxidative damage in glioma cells by inhibiting the PI3K/AKT/mTOR signaling pathway.

Doxorubicin as a fluorescent reporter identifies novel MRP1 (ABCC1) inhibitors missed by calcein-based high content screening of anticancer agents

Multidrug resistance protein 1 (MRP1/ABCC1) actively transports a variety of drugs, toxic molecules and important physiological substrates across the plasma membrane. It can confer broad-spectrum multidrug resistance and can decrease the bioavailability of many important drugs. Substrates of MRP1 include anti-cancer agents, antibiotics, antivirals, antidepressants and anti-inflammatory drugs. Using calcein as a fluorescent reporter in a high content uptake assay, we recently reported the identification of 12 MRP1 inhibitors after screening an anti-cancer library of 386 compounds. Here, we describe the development of a new high content imaging-based uptake assay using doxorubicin as a fluorescent reporter. Screening the same anti-cancer library of 386 compounds, the new assay identified a total of 28 MRP1 inhibitors including 16 inhibitors that have not been previously reported as inhibitors of MRP1. Inhibition of MRP1 activity was confirmed using flow cytometry and confocal microscopy-based transport assays. Six drugs (afatinib, celecoxib, doramapimod, mifepristone, MK-2206 and rosiglitazone) were evaluated for their ability to reverse resistance of MRP1-overexpressing H69AR lung cancer cells against vincristine, doxorubicin and etoposide. Mifepristone and doramapimod were most effective in reversal of resistance against vincristine while mifepristone and rosiglitazone were most successful in resensitizing H69AR cells against doxorubicin. Furthermore, resistance towards etoposide was completely reversed in the presence of celecoxib or doramapimod. Selected drugs were also evaluated for resistance reversal in HEK cells that overexpress P-glycoprotein or breast cancer resistance protein. Our results indicate mifepristone and doramapimod as pan inhibitors of these three drug transporters while celecoxib exhibited selective MRP1 inhibition. Together, our findings signify the importance of MRP1 in drug discovery and demonstrate the effectiveness and value of doxorubicin-based high content screening approach. Anti-cancer agents that exhibit MRP1 inhibition may be used to reverse multidrug resistance or to improve the efficacy and reduce the toxicity of various cancer chemotherapies. On the other hand, anti-cancer drugs that did not interact with MRP1 carry a low risk for developing MRP1-mediated resistance.

Potential Anticancer Agents Characterized from Selected Tropical Plants

Higher plants are well known for their value in affording clinically useful anticancer agents, with such compounds acting against cancer cells by a range of mechanisms of action. There remains a strong interest in the discovery and development of plant secondary metabolites as additional cancer chemotherapeutic lead compounds. In the present review, progress on the discovery of plant-derived compounds of the biflavonoid, lignan, sesquiterpene, steroid, and xanthone structural types is presented. Several potential anticancer leads of these types have been characterized from tropical plants collected in three countries as part of our ongoing collaborative multi-institutional project. Preliminary structure-activity relationships and work on in vivo testing and cellular mechanisms of action are also discussed. In addition, the relevant work reported by other groups on the same compound classes is included herein.

An LC-MS/MS Method for Synchronous Determination of Paclitaxel and Curcumin: Development, Validation, and Application to a Pharmacokinetic Study

Background:

A chromatography tandem mass spectrometry method was first established and validated for the synchronous determination of curcumin(CUR) and paclitaxel (PTX) in this study. </P><P> Objective: An LC-MS/MS Method for Determination of Paclitaxel and Curcumin.

Methods:

The analytes were extracted with methanol, and docetaxel was used as the internal standard (IS). The analytes and the IS were separated on a C18 (4.6 mm × 50 mm, 3.5 µm) column with a mobile phase of 0.1% formic acid solution and methanol (80:20, v/v). The flow velocity of the mobile phase was 0.5 mL/min. And then, the method was applied to study the pharmacokinetic behavior of CUR and PTX in rats.

Results:

The calibration curves were linear within the concentration ranges of 2–1000 ng/mL for PTX and 5–500 ng/mL for CUR, the mean extraction recoveries and matrix effects of PTX, CUR, and the IS were within an acceptable range. The apparent volume of distribution of PTX was different between the group of administration of PTX and the group of co-administration with CUR and PTX.

Conclusion:

A sensitive and simple liquid chromatography-tandem mass spectrometry method was established and validated for the synchronous determination of PTX and CUR in rat plasma, CUR increased the apparent volume of distribution of PTX when CUR and PTX were co-administered.

Inhibitors of Human ABCG2: From Technical Background to Recent Updates With Clinical Implications

The ATP-binding cassette transporter G2 (ABCG2; also known as breast cancer resistance protein, BCRP) has been suggested to be involved in clinical multidrug resistance (MDR) in cancer like other ABC transporters such as ABCB1 (P-glycoprotein). As an efflux pump exhibiting a broad substrate specificity localized on cellular plasma membrane, ABCG2 excretes a variety of endogenous and exogenous substrates including chemotherapeutic agents, such as mitoxantrone and several tyrosine kinase inhibitors. Moreover, in the normal tissues, ABCG2 is expressed on the apical membranes and plays a pivotal role in tissue protection against various xenobiotics. For this reason, ABCG2 is recognized to be an important determinant of the pharmacokinetic characteristics of its substrate drugs. Although the clinical relevance of reversing the ABCG2-mediated MDR has been inconclusive, an appropriate modulation of ABCG2 function during chemotherapy should logically enhance the efficacy of anti-cancer agents by overcoming the MDR phenotype and/or improving their pharmacokinetics. To confirm this possibility, considerable efforts have been devoted to developing ABCG2 inhibitors, although there is no clinically available substance for this purpose. As a clue for addressing this issue, this mini-review provides integrated information covering the technical backgrounds necessary to evaluate the ABCG2 inhibitory effects on the target compounds and a current update on the ABCG2 inhibitors. This essentially includes our recent findings, as we serendipitously identified febuxostat, a well-used agent for hyperuricemia as a strong ABCG2 inhibitor, that possesses some promising potentials. We hope that an overview described here will add value to further studies involving in the multidrug transporters.

Recent updates on metabolite composition and medicinal benefits of mangosteen plant

BACKGROUND

Mangosteen (Garcinia mangostana L.) fruit has a unique sweet-sour taste and is rich in beneficial compounds such as xanthones. Mangosteen originally been used in various folk medicines to treat diarrhea, wounds, and fever. More recently, it had been used as a major component in health supplement products for weight loss and for promoting general health. This is perhaps due to its known medicinal benefits, including as anti-oxidant and anti-inflammation. Interestingly, publications related to mangosteen have surged in recent years, suggesting its popularity and usefulness in research laboratories. However, there are still no updated reviews (up to 2018) in this booming research area, particularly on its metabolite composition and medicinal benefits.

METHOD

In this review, we have covered recent articles within the years of 2016 to 2018 which focus on several aspects including the latest findings on the compound composition of mangosteen fruit as well as its medicinal usages.

RESULT

Mangosteen has been vastly used in medicinal areas including in anti-cancer, anti-microbial, and anti-diabetes treatments. Furthermore, we have also described the benefits of mangosteen extract in protecting various human organs such as liver, skin, joint, eye, neuron, bowel, and cardiovascular tissues against disorders and diseases.

CONCLUSION

All in all, this review describes the numerous manipulations of mangosteen extracted compounds in medicinal areas and highlights the current trend of its research. This will be important for future directed research and may allow researchers to tackle the next big challenge in mangosteen study: drug development and human applications.

Natural compound Oblongifolin C confers gemcitabine resistance in pancreatic cancer by downregulating Src/MAPK/ERK pathways

Gemcitabine (GEM)-induced drug resistance is the major reason for the failure of chemotherapy in pancreatic cancer (PC). In this study, we found that Oblongifolin C (OC) efficiently inhibited PC cell proliferation by inducing G0/G1 arrest and apoptosis. Also, our mechanism study demonstrated that OC re-sensitized the GEM-resistant PC cells through the ubiquitin-proteasome-dependent degradation of Src, and then downregulating the MAPK pathway. Knockdown of Src plus OC resulted in a greater inhibitory effect in GEM-resistant PC cells. In contrast, Src overexpression reversed OC-mediated chemosensitization, thereby implicating Src in the action of OC. Moreover, our in vivo study showed that OC suppressed the tumor growth via the downregulation of Src, and enhanced the chemosensitivity of GEM-resistant PC to GEM. Overall, our results have revealed that OC is applicable as a promising agent for overcoming GEM-resistant PC, especially with aberrant Src expression.

Antibiofilm activity of α-mangostin extracted from Garcinia mangostana L. against Staphylococcus aureus

OBJECTIVE

To isolate α-mangostin (AMG) from the peels of mangosteen (Garcinia mangostana L.), grown in Vietnam, and to investigate antibiofilm activity of this compound against three Staphylococcus aureus (S. aureus) strains, one of which was methicillin-resistant S. aureus (MRSA) and the other two strains were methicillin-sensitive S. aureus (MSSA).

METHODS

AMG in n-hexane fraction was isolated on a silica gel column and chemically analyzed by HPLC and NMR. The antibiofilm activity of this compound was investigated by using a 96-well plate model for the formation of biofilms. Biofilm biomass was quantified using crystal violet. The viability of cells was observed under confocal microscopy using LIVE/DEAD BacLight stains. Biofilm composition was determined using specific chemical and enzyme tests for polysaccharide, protein and DNA. Membrane-damaging activity was assayed by measuring the hemolysis of human red blood cells in presence of AMG.

RESULTS

The results indicated that the isolated AMG, with a purity that exceeded 98%, had minimal inhibitory concentrations in the range of 4.6-9.2 μmol/L for the three strains tested. Interestingly, the MSSA strains were more sensitive to AMG than the MRSA strain. Minimal bactericidal concentrations were 2-fold higher than the minimal inhibitory concentration values for the three strains, indicating that AMG was a bactericidal compound. AMG also prevented biofilm formation effectively, albeit that again the MRSA strain was the most resistant. Interestingly, biofilms of the MRSA strain contained protein as a main component of the extracellular matrix, whereas this was polysaccharide in the MSSA strains. This might relate to the resistance of the MRSA 252 strain to AMG. Assays using human red blood cells indicated that AMG caused significant membrane damage with 50% of cell lysis occurred at concentration of about 36 μmol/L.

CONCLUSIONS

Our results provide evidence that the isolated AMG has inhibitory activity against biofilm formation by S. aureus, including MRSA. Thus, isolated AMG proposes a high potential to develop a novel phytopharmaceutical for the treatment of MRSA.