mangostin and Glioma

Two of the biggest hurdles in the deployment of chemotherapeutics against glioma is a poor drug concentration at the tumor site and serious side effects to normal tissues. Nanocarriers delivering different drugs are considered to be one of the most promising alternatives. In this study, a dual delivery system (methoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL)) loaded with α-mangostin (α-m) and doxorubicin (Dox) was decorated and constructed by self-assembly to determine its ability to treat glioma. Molecular dynamics simulations showed that MPEG-PCL could provide ideal interaction positions for both α-m and Dox, indicating that the two drugs could be loaded into MPEG-PCL. Based on the in vitro results, MPEG-PCL loaded with α-m and Dox (α-m-Dox/M) with a size of 25.68 nm and a potential of -1.51 mV was demonstrated to significantly inhibit the growth and promote apoptosis in Gl261, C6 and U87 cells, and the effects of the combination were better than each compound alone. The mechanisms involved in the suppression of glioma cell growth were blockage of the cell cycle in S phase by inhibition of CDK2/cyclin E1 and promotion of apoptosis through the Bcl-2/Bax pathway. The synergetic effects of α-m-Dox/M effectively inhibited tumor growth and prolonged survival time without toxicity in mouse glioma models by inducing glioma apoptosis, inhibiting glioma proliferation and limiting tumor angiogenesis. In conclusion, a codelivery system was synthesized to deliver α-m and Dox to the glioma, thereby suppressing the development of glioma by the mechanisms of cell cycle arrest and cellular apoptosis, which demonstrated the potential of this system to improve the chemotherapy response of glioma.

Topics: Animals; Apoptosis; Cell Cycle Checkpoints; Doxorubicin; Glioma; Humans; Mice; Mice, Nude; Models, Molecular; Xanthones

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. 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.. 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.. 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.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Proliferation; Cell Survival; Drug Screening Assays, Antitumor; Garcinia mangostana; Glioma; Oxidative Stress; Phosphatidylinositol 3-Kinases; Plant Extracts; Proto-Oncogene Proteins c-akt; Rats; TOR Serine-Threonine Kinases; Tumor Cells, Cultured; Xanthones

Mangostin is a hydrophobic agent with potential anticancer activity. Molecular dynamics computer simulation indicated methoxy poly(ethylene glycol)-poly(lactide) (MPEG-PLA) and α-mangostin (α-M) have good compatibility. The α-M-loaded nano-particles acting as an anticancer agents against growth of glioma cells were prepared by self-assembly methods. In this study, the effects of α-M-loaded nano-particles, α-M/MPEG-PLA with drug loading of 15% and a mean particle size of 32 nm, on the growth of glioma cells were examined both in vitro and in vivo. The occurrence of changes in the cell signaling molecules and expression levels of various proteins related to cell death and glioma xenograft models (i.e., zebra fish, subcutaneous-mouse and orthotopic-mouse) growth following the administration of α-M/MPEG-PLA were investigated. The novel α-M/MPEG-PLA inhibited the growth of malignant glioma cells, induced cells apoptosis with cleaved caspases expression and DNA fragmentation, along with down-regulation of anti-apoptotic molecules and up-regulation of apoptotic molecules. Furthermore, decreased proliferation as well as vascularization of the tumor in vivo models were significantly achieved. A dramatic induction of programmed cell death was found in malignant glioma cells after treatment with synthetic α-M/MPEG-PLA. These results suggest that synthetic α-M/MPEG-PLA could be a promising novel anticancer agent for performing chemotherapy against malignant glioma.

Topics: Animals; Antineoplastic Agents; Cell Death; Cell Line, Tumor; Computer Simulation; Drug Carriers; Glioma; Mice; Micelles; Particle Size; Polyesters; Polyethylene Glycols; Xanthones

Gliomas are a common type of primary brain tumor with glioblastoma multiforme accounting for the majority of human brain tumors. In this paper, high grade human malignant glioblastomas (MGs) including U87 MG and GBM 8401 were used to evaluate the antitumor effects of γ-mangostin, a xanthone derivative isolated and purified from the hull of the tropical fruit Garcinia mangostana. The γ-mangostin showed potent antiproliferative activity toward MGs in dose- and time-dependent manners. In addition, flow cytometric analysis of cell morphology in the apoptotic cells revealed an increase in hypodiploid cells in γ-mangostin treated U87 MG and GBM 8401 cells, while significant enhancement of intracellular peroxide production was detected in the same γ-mangostin treated cells by DCHDA assay and DiOC(6)(3) stain. g-Mangostin induced apoptosis, which in turn mediates cytotoxicity in human MG cells was prevented by the addition of catalase. Naturally derived medicines and herbal therapies are drawing increasing attention in regard to the treatment of many health issues, and this includes the testing of new phytochemicals or nutrients for brain tumor patients. This has led to γ-mangostin being identified as a potential leading compound for the development of an anti-brain tumor agent.

Topics: Antineoplastic Agents; Apoptosis; Brain Neoplasms; Cell Line, Tumor; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Fruit; Garcinia mangostana; Glioma; Humans; Phytotherapy; Time Factors; Xanthones

In the course of our survey of natural compounds inhibiting prostaglandin E2 release and/or lipopolysaccharide (LPS)-induced transcriptional stimulation via NF-kappaB, a central regulator of inflammatory genes, from natural resources, we found garcinone B, a xanthone from callus tissue culture of Hypericum patulum, as a compound with such pharmacological activities, that is a derivative of gamma-mangostin which potently inhibits COX-1 and COX-2 activities to reduce PGE2 release from C6 rat glioma cells, and inhibits IKK activity to prevent NF-kappaB-dependent COX-2 gene transcription. Garcinone B, to a lesser extent, reduced A23187-induced increase in prostaglandin E2 release than gamma-mangostin and its structurally related compound, patulone, in C6 cells. This compound also prevented LPS-induced stimulation of NF-kappaB-dependent transcription. These results suggest that garcinone B becomes a unique pharmacological tool to investigate intracellular signaling pathways involved in inflammation.

Topics: Animals; Brain Neoplasms; Calcimycin; Cell Line, Tumor; Cyclooxygenase 1; Dinoprostone; Glioma; Hypericum; Inflammation Mediators; Lipopolysaccharides; NF-kappa B; Prostaglandin Antagonists; Rats; Transcription, Genetic; Xanthines; Xanthones

We investigated the effect of gamma-mangostin purified from the fruit hull of the medicinal plant Garcinia mangostana on spontaneous prostaglandin E(2) (PGE(2)) genase release and inducible cyclooxy-2 (COX-2) gene expression in C6 rat glioma cells. An 18-h treatment with gamma-mangostin potently inhibited spontaneous PGE(2) release in a concentration-dependent manner with the IC(50) value of approximately 2 microM, without affecting the cell viability even at 30 microM. By immunoblotting and reverse-transcription polymerase chain reaction, we showed that gamma-mangostin concentration-dependently inhibited lipopolysaccharide (LPS)-induced expression of COX-2 protein and its mRNA, but not those of constitutive COX-1 cyclooxygenase. Because LPS is known to stimulate inhibitor kappaB (IkappaB) kinase (IKK)-mediated phosphorylation of IkappaB followed by its degradation, which in turn induces nuclear factor (NF)-kappaB nuclear translocation leading to transcriptional activation of COX-2 gene, the effect of gamma-mangostin on the IKK/IkappaB cascade controlling the NF-kappaB activation was examined. An in vitro IKK assay using IKK protein immunoprecipitated from C6 cell extract showed that this compound inhibited IKK activity in a concentration-dependent manner, with the IC(50) value of approximately 10 microM. Consistently gamma-mangostin was also observed to decrease the LPS-induced IkappaB degradation and phosphorylation in a concentration-dependent manner, as assayed by immunoblotting. Furthermore, luciferase reporter assays showed that gamma-mangostin reduced the LPS-inducible activation of NF-kappaB-and human COX-2 gene promoter region-dependent transcription. gamma-Mangostin also inhibited rat carrageenan-induced paw edema. These results suggest that gamma-mangostin directly inhibits IKK activity and thereby prevents COX-2 gene transcription, an NF-kappaB target gene, probably to decrease the inflammatory agent-stimulated PGE(2) production in vivo, and is a new useful lead compound for anti-inflammatory drug development.

Topics: Animals; Brain Neoplasms; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Drug Interactions; Gene Expression; Glioma; I-kappa B Kinase; I-kappa B Proteins; Isoenzymes; Lipopolysaccharides; Male; Membrane Proteins; NF-kappa B; Pain; Prostaglandin-Endoperoxide Synthases; Protein Serine-Threonine Kinases; Rats; Rats, Wistar; RNA, Messenger; Transcriptional Activation; Tumor Cells, Cultured; Xanthones

The fruit hull of mangosteen, Garcinia mangostana L., has been used for many years as a medicine for treatment of skin infection, wounds, and diarrhea in Southeast Asia. In the present study, we examined the effect of gamma-mangostin, a tetraoxygenated diprenylated xanthone contained in mangosteen, on arachidonic acid (AA) cascade in C6 rat glioma cells. gamma-Mangostin had a potent inhibitory activity of prostaglandin E2 (PGE2) release induced by A23187, a Ca2+ ionophore. The inhibition was concentration-dependent, with the IC50 value of about 5 microM. gamma-Mangostin had no inhibitory effect on A23187-induced phosphorylation of p42/p44 extracellular signal regulated kinase/mitogen-activated protein kinase or on the liberation of [14C]-AA from the cells labeled with [14C]-AA. However, gamma-mangostin concentration-dependently inhibited the conversion of AA to PGE2 in microsomal preparations, showing its possible inhibition of cyclooxygenase (COX). In enzyme assay in vitro, gamma-mangostin inhibited the activities of both constitutive COX (COX-1) and inducible COX (COX-2) in a concentration-dependent manner, with the IC50 values of about 0.8 and 2 microM, respectively. Lineweaver-Burk plot analysis indicated that gamma-mangostin competitively inhibited the activities of both COX-1 and -2. This study is a first demonstration that gamma-mangostin, a xanthone derivative, directly inhibits COX activity.

Topics: Animals; Arachidonic Acid; Calcimycin; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Drug Interactions; Garcinia mangostana; Glioma; HIV Protease Inhibitors; Isoenzymes; Membrane Proteins; Microsomes; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Phosphorylation; Prostaglandin-Endoperoxide Synthases; Protein Synthesis Inhibitors; Rats; Tumor Cells, Cultured; Xanthenes; Xanthones