The purple mangosteen (Garcinia mangostana): Defining the anticancer potential of selected xanthones

Aptamers for the Delivery of Plant-Based Compounds: A Review

Natural compounds have a high potential for the treatment of various conditions, including infections, inflammatory diseases, and cancer. However, they usually present poor pharmacokinetics, low specificity, and even toxicity, which limits their use. Therefore, targeted drug delivery systems, typically composed of a carrier and a targeting ligand, can enhance natural product selectivity and effectiveness. Notably, aptamers-short RNA or single-stranded DNA molecules-have gained attention as promising ligands in targeted drug delivery since they are simple to synthesize and modify, and they present high tissue permeability, stability, and a wide array of available targets. The combination of natural products, namely plant-based compounds, with a drug delivery system utilizing aptamers as targeting agents represents an emerging strategy that has the potential to broaden its applications. This review discusses the potential of aptamers as targeting agents in the delivery of natural compounds, as well as new trends and developments in their utilization in the field of medicine.

Preparation and evaluation of a niosomal delivery system containing G. mangostana extract and study of its anti-Acanthamoeba activity

Garcinia mangostana extract (GME) has severe pharmacokinetic deficiencies and is made up of a variety of bioactive components. GME has proven its anti-Acanthamoeba effectiveness. In this investigation, a GME-loaded niosome was developed to increase its potential therapeutic efficacy. A GME-loaded niosome was prepared by encapsulation in a mixture of span60, cholesterol, and chloroform by the thin film hydration method. The vesicle size, zeta potential, percentage of entrapment efficiency, and stability of GME-loaded niosomes were investigated. The values for GME-loaded niosome size and zeta potential were 404.23 ± 4.59 and -32.03 ± 0.95, respectively. The delivery system enhanced the anti-Acanthamoeba activity, which possessed MIC values of 0.25-4 mg mL-1. In addition, the niosomal formulation decreased the toxicity of GME by 16 times. GME-loaded niosome must be stored at 4 °C, as the quantity of remaining GME encapsulated is greater at this temperature than at room temperature. SEM revealed the damage to the cell membrane caused by trophozoites and cysts, which led to dead cells. In light of the above, it was found that GME-loaded niosomes had better anti-Acanthamoeba activity. The study suggested that GME-loaded niosomes could be used as an alternative to Acanthamoeba's therapeutic effects.

Garcinone C attenuates RANKL-induced osteoclast differentiation and oxidative stress by activating Nrf2/HO-1 and inhibiting the NF-kB signaling pathway

Osteoporosis is the result of osteoclast formation exceeding osteoblast production, and current osteoporosis treatments targeting excessive osteoclast bone resorption have serious adverse effects. There is a need to fully understand the mechanisms of osteoclast-mediated bone resorption, identify new drug targets, and find better drugs to treat osteoporosis. Gar C (Gar C) is a major naturally occurring phytochemical isolated from mangosteen, and is a derivative of the naturally occurring phenolic antioxidant lutein. We used an OP mouse model established by ovariectomy (OVX). We found that treatment with Gar C significantly increased bone mineral density and significantly decreased the expression of TRAP, NFATC1 and CTSK relative to untreated OP mice. We found that Garcinone C could disrupt osteoclast activation and resorption functions by inhibiting RANKL-induced osteoclast differentiation as well as inhibiting the formation of multinucleated osteoclasts. Immunoblotting showed that Gar C downregulated the expression of osteoclast-related proteins. In addition, Gar C significantly inhibited RANKL-induced ROS production and affected NF-κB activity by inhibiting phosphorylation Formylation of P65 and phosphorylation and degradation of ikba. These data suggest that Gar C significantly reduced OVX-induced osteoporosis by inhibiting osteoclastogenesis and oxidative stress in bone tissue. Mechanistically, this effect was associated with inhibition of the ROS-mediated NF-κB pathway.

Structure and activity relationship analysis of xanthones from mangosteen: Identifying garcinone E as a potent dual EGFR and VEGFR2 inhibitor

BACKGROUND

Xanthones are among the most fundamental phytochemicals in nature. The anti-cancer activities of xanthones and their derivatives have been extensively studied. Recently, we found that garcinone E (GE), an effective anti-cancer phytochemical isolated from mangosteen (Garcinia mangostanal.), showed promising anti-cancer effects in vitro and in vivo. However, little is known about its effects on epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor 2 (VEGFR2) activity.

PURPOSE

This study aimed to identify potent dual EGFR and VEGFR2 inhibitors from mangosteen-derived xanthones using structure-activity relationship analyses.

STUDY DESIGN

The interaction of xanthones with EGFR and VEGFR2 was analyzed using molecular docking experiments. The kinase activities of EGFR and VEGFR2 were determined using bioluminescence assays. The rat aortic ring and Matrigel plug angiogenesis assays were used to evaluate blood vessel formation ex vivo and in vivo. A breast tumor-bearing nude mouse model was established to examine the anti-tumor effects of different xanthones.

RESULTS

Molecular docking analysis showed that GE bound tightly to EGFR and VEGFR2, with binding energies of -9.73 and -9.56 kcal/mol, respectively. Kinase activity assessment showed that GE strongly inhibited both EGFR and VEGFR2 kinase activity, with IC50 values of 315.4 and 158.2 nM, respectively. Moreover, GE significantly abolished the EGF- and VEGF-induced phosphorylation of EGFR and VEGFR2, respectively. GE also showed strong inhibitory effects on cancer cell growth, endothelial cell migration, invasion, and tube formation. Ex vivo and in vivo angiogenesis assays showed that GE dose-dependently suppressed blood vessel formation in the rat aorta, Matrigel plugs, and transgenic zebrafish embryos, with the lowest effective concentration of 0.25 μM. Furthermore, GE (2 mg/kg) strongly inhibited tumor growth and reduced tumor weight in MDA-MB-231 breast tumor-xenografted mice. GE significantly reduced microvessel density and downregulated the expression of VEGFR2, EGFR, and Ki67 in tumor tissues.

CONCLUSION

The present study demonstrated that GE was the most potent dual inhibitor of EGFR and VEGFR2 among all xanthones tested. These findings may provide valuable information for the future development of novel and effective dual inhibitors of EGFR and VEGFR2.

The protective effects of beta-mangostin against sodium iodate-induced retinal ROS-mediated apoptosis through MEK/ERK and p53 signaling pathways

Previous studies have indicated that NaIO3 induces intracellular reactive oxygen species (ROS) production and has been used as a model for age-related macular degeneration (AMD) due to the selective retinal pigment epithelium (RPE) cell damage it induces. Beta-mangostin (BM) is a xanthone-type natural compound isolated from Cratoxylum arborescens. The influence of BM on NaIO3-induced oxidative stress damage in ARPE-19 cells has not yet been elucidated. In this study, we investigated how BM protects ARPE-19 cells from NaIO3-induced ROS-mediated apoptosis. Our results revealed that BM notably improved cell viability and prevented ARPE-19 cell mitochondrial dysfunction mediated-apoptosis induced by NaIO3; it was mediated by significantly reduced NaIO3-upregulated ROS, cellular H2O2 production and improved downregulated glutathione and catalase activities. Furthermore, we found that BM could suppress the expression of Bax, cleaved PARP, and cleaved caspase-3 by decreasing phosphorylation of MEK/ERK and p53 expression in NaIO3-induced ARPE-19 cells. At the same time, we also used MEK inhibitors (PD98059) to confirm the above phenomenon. Moreover, our animal experiments revealed that BM prevented NaIO3 from causing retinal deformation; it led to thicker outer and inner nuclear layers and downregulated cleaved caspase-3 expression compared to the group receiving NaIO3 only. Collectively, these results suggest that BM can protect the RPE and retina from NaIO3-induced apoptosis through ROS-mediated mitochondrial dysfunction involving the MEK/ERK and p53 signaling pathways.

Demethylcalabaxanthone from Garcinia mangostana Exerts Antioxidant Effects through the Activation of the Nrf2 Pathway as Assessed via Molecular Docking and Biological Evaluation

Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway activation promotes the expression of antioxidant enzymes in response to rising oxidative stress, resulting in reactive oxygen species (ROS) detoxification and playing a central role in the maintenance of intracellular redox homeostasis and regulation of inflammation. Moreover, the biological effects of Nrf2 pathway activation contribute to reducing apoptosis and enhancing cell survival. The activity of Nrf2 is negatively regulated by Kelch-like ECH-associated protein 1 (Keap1). Prompted by the recent results reporting the impact of xanthone metabolites on oxidative stress, cancer, and inflammation, the antioxidant properties of xanthones isolated from Garcinia mangostana (γ-mangostin, α-mangostin, 8-deoxygartanin, demethylcalabaxanthone, garcinone D) were assessed. In particular, the capability of these natural products to disrupt the interaction between Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2), triggering the activation of the Nrf2-mediated pathway, was evaluated using molecular docking experiments and in vitro tests. The modulation of some key Nrf2-related mediators like glutathione (GSH) and lactate dehydrogenase (LDH) to highlight a possible direct antioxidant effect was investigated. Among the tested compounds, demethylcalabaxanthone showed an indirect antioxidant effect, as corroborated by a Western blot assay, displaying a significant increase in the translocated protein upon its administration.

Dietary γ-mangostin triggers immunogenic cell death and activates cGAS signaling in acute myeloid leukemia

Immunogenic cell death (ICD), one of cell-death types through release of damage-associated molecular patterns from dying tumor cells, activates tumor-specific immune response and elicits anti-tumor immunity by traditional radiotherapy and chemotherapy. However, whether natural products could induce ICD in leukemia is not elucidated. Here, we report dietary γ-mangostin eradicates murine primary leukemic cells and prolongs the survival of leukemic mice. As well, it restrains primary leukemic cells and CD34+ leukemic progenitor cells from leukemia patients. Strikingly, γ-mangostin attenuates leukemic cells by inducing ICD as characterized by expression of HSP90B1, ANXA1 and IL1B. Additionally, γ-mangostin accelerates cytoplasmic chromatin fragments generation, promoting DNA damage response, and enhances cGAS activation, leading to up-regulation of chemokines. Meanwhile, it induces HDAC4 degradation and acetylated histone H3 accumulation, which promotes chemokines transcription. Ultimately, CD8+ T cell is activated and recruited by γ-mangostin-induced chemokines in the microenvironment. Our study identifies γ-mangostin triggers ICD and activates cGAS signaling through DNA damage response and epigenetic modification. Therefore, dietary γ-mangostin would act as a potential agent to provoke anti-tumor immunity in the prevention and treatment of leukemia.

Garcinone E suppresses breast cancer growth and metastasis by modulating tumor-associated macrophages polarization via STAT6 signaling

Cancer metastasis remains the most common cause of death in breast cancer patients. Tumor-associated macrophages (TAMs) are a novel therapeutic target for the treatment of metastatic breast cancer. Despite the good anti-cancer activity of garcinone E (GE), there are no reports on its therapeutic effects on breast cancer metastasis. The objective of this study was to examine the anti-cancer effects of GE on metastatic breast cancer. RAW 264.7 and THP-1 cells were polarized to M2 macrophages by IL-4/IL-13 in vitro. A 4T1 mouse breast cancer model and the tail vein breast cancer metastasis model were used to explore the effect of GE on breast cancer growth and metastasis in vivo. In vitro studies showed that GE dose-dependently suppressed IL-4 + IL-13-induced expression of CD206 in both RAW 264.7 cells and differentiated THP-1 macrophages. However, GE did not affect the LPS + IFN-γ-induced polarization to the M1-like macrophages in vitro. GE inhibited the expression of the M2 macrophage specific genes in RAW 264.7 cells, and simultaneously impaired M2 macrophage-induced breast cancer cell proliferation and migration, and angiogenesis. In animal studies, GE significantly suppressed tumor growth, angiogenesis, and lung metastasis in 4T1 tumor-bearing mice, without causing toxicity. In both tumor and lung tissues, the proportion of M2-like TAMs was significantly decreased while the proportion of M1-like TAMs was markedly increased by GE treatment. Mechanistically, GE inhibited phosphorylation of STAT6 in vitro and in vivo. Our results demonstrate for the first time that GE suppresses breast cancer growth and pulmonary metastasis by modulating M2-like macrophage polarization through the STAT6 signaling pathway.

α-Mangostin Suppresses Melanoma Growth, Migration, and Invasion and Potentiates the Anti-tumor Effect of Chemotherapy

Purpose: Melanoma is a highly malignant tumor, which metastasizes and has poor prognosis in late-stage cancer patients. α-Mangostin possesses pharmacological properties, including antioxidant, anti-infective, and anticarcinogenic activities. We investigated α-Mangostin effect on melanoma growth, migration, and invasion and its possible molecular mechanism. Methods: Melanoma cells growth inhibition was determined by the colorimetric 4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. Morphological changes of α-Mangostin-treated melanoma cells were evaluated by transmission electron microscopy and JC-1 staining. Cell apoptosis and cell cycle arrest were assessed by flow cytometry. The effect of α-Mangostin on tumor cells migration and invasion was observed by migration and invasion in vitro assay. Furthermore, the nude and C57BL/6 mouse subcutaneous melanoma models were used to evaluate the in vivo anti-tumor effect of α-Mangostin. Western blot and real time-PCR were performed to analyze the influence of α-Mangostin on some of the common signaling pathways in melanoma cell lines. Signaling pathways were further verified in dissected tumor tissues. Results: α-Mangostin inhibited in vitro melanoma cells proliferation, migration, and invasion of melanoma cells, induced cell cycle arrest in G0/G1 phase, and caused mitochondrial swelling and membrane depolarization, whereas it effectively suppressed melanoma growth in xenografted mice. In addition, α-Mangostin potentiated the in vitro and in vivo anti-tumor effects of cisplatin both in vitro and in vivo. Mechanistically, α-Mangostin down-regulated expression of RAS protein and mRNA, as well as phosphorylation of PI3K in A375, B16F10, M14 and SK-MEL-2 cells. MITF protein and mRNA were inhibited only in M14 cells. Conclusion: α-Mangostin suppresses melanoma cells growth, migration and invasion, and synergistically enhances the anti-tumor effect of chemotherapy, whose mechanism may be mediated through inhibiting Ras, PI3K and MITF.

Bioactivities of β-mangostin and its new glycoside derivatives synthesized by enzymatic reactions

Beta-mangostin is a xanthone commonly found in the genus Garcinia. Unlike α-mangostin, to date, there have only been a few studies on the biological activity and derivatization of β-mangostin. In this study, two novel glycosylated derivatives of β-mangostin were successfully synthesized via a one-pot enzymatic reaction. These derivatives were characterized as β-mangostin 6-O-β-d-glucopyranoside and β-mangostin 6-O-β-d-2-deoxyglucopyranoside by TOF ESI/MS and 1H and 13C NMR analyses. Beta-mangostin showed cytotoxicity against KB, MCF7, A549 and HepG2 cancer cell lines, with IC50 values ranging from 15.42 to 21.13 µM. The acetylcholinesterase and α-glucosidase inhibitory activities of β-mangostin were determined with IC50 values of 2.17 and 27.61 µM, respectively. A strong anti-microbial activity of β-mangostin against Gram-positive strains (Bacillus subtilis, Lactobacillus fermentum and Staphylococcus aureus) was observed, with IC50 values of 0.16, 0.18 and 1.24 µg ml-1, respectively. Beta-mangostin showed weaker activity against Gram-negative strains (Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa) as well as Candida albicans fungus, with IC50 and MIC values greater than the tested concentration (greater than 32 µg ml-1). The new derivatives of β-mangostin showed weaker activities than those of β-mangostin, demonstrating the important role of the hydroxyl group at C-6 of β-mangostin in its bioactivity.

Garcinone E triggers apoptosis and cell cycle arrest in human colorectal cancer cells by mediating a reactive oxygen species–dependent JNK signaling pathway

Despite various therapeutic approaches, colorectal cancer is among the most fatal diseases globally. Hence, developing novel and more effective methods for colorectal cancer treatment is essential. Recently, reactive oxygen species (ROS)/JNK signaling pathway has been proposed as the potential target for the anticancer drug discovery. The present study investigated the anticancer effects of the bioactive xanthone garcinone E (GAR E) in mangosteen and explored its underlying mechanism of action. HT-29 and Caco-2 cancer cells were used as in vitro models to study the anticancer effect of GAR E. The findings demonstrated that GAR E inhibited colony formation and wound healing, whereas triggered the production of ROS, which induced mitochondrial dysfunction and apoptosis, causing cell cycle arrest at the Sub G1 phase. Additionally, GAR E treatment elevated the ratio of Bax/Bcl-2 and activated PARP, caspases 3 and 9, and JNK1/2. These GAR E-induced cytotoxic activities and expression of signaling proteins were reversed by the antioxidant N-acetyl-L-cysteine and JNK inhibitor SP600125, indicating the involvement of ROS/JNK signaling pathways. In vivo experiments using an HT-29 xenograft nude mouse model also demonstrated the antitumor effect of GAR E. In conclusion, our findings showed that GAR E might be potentially effective in treating colorectal cancer and provided insights into the development of xanthones as novel chemotherapeutic agents.

γ-Mangostin abrogates AINT-induced cholestatic liver injury: Impact on Nrf2/NF-κB/NLRP3/Caspase-1/IL-1β/GSDMD signalling

γ-Mangostin (γ-MN) is one of the abundant xanthones separated from Garcinia mangostana (Clusiaceae) pericarps that has been reported to have varied bioactivities such as neuroprotective, cytotoxic, antihyperglycemic, antioxidant, and anti-inflammation. Yet, its effect on cholestatic liver damage (CLI) has not been investigated. This study explored the protective activity of γ-MN against alpha-naphthyl isothiocyanate (ANIT)-induced CLI in mice. The results showed that γ-MN protected against ANIT-induced CLI as indicated by reduced serum levels of hepatic injury parameters (e.g., ALT, AST, γ-GT, ALP, LDH, bilirubin, and total bile acids). ANIT-induced pathological lesions were improved in γ-MN pre-treated groups. γ-MN exerted potent antioxidant effects as it lowered the parameters of lipid peroxidation (4-HNE, PC, and MDA) and intensified the content and activity of antioxidants (TAC, GSH, GSH-Px, GST, and SOD) in the hepatic tissue. Furthermore, γ-MN enhanced the signalling of Nrf2/HO-1 as it augmented the mRNA expression of Nrf2/downstream genes (HO-1/GCLc/NQO1/SOD). The binding capacity and the immuno-expression of Nrf2 were also increased. γ-MN showed anti-inflammatory capacity as it suppressed the activation of NF-κB signalling, it decreased mRNA expression and levels of NF-κB/TNF-α/IL-6 and the immuno-expression of NF-κB/TNF-α. In addition, γ-MN inhibited the activation of NLRP3 inflammasome as it lowered the mRNA expression of NLRP3/caspase-1/IL-1β along with their levels as well as the immuno-expression of caspase-1/IL-1β. γ-MN also reduced the level of the pyroptotic parameter GSDMD. Collectively, this study demonstrated the potent hepatoprotective potential of γ-MN against CLI which was linked to its ability to potentiate Nrf2/HO-1 and to offset NF-κB/NLRP3/Caspase-1/IL-1β/GSDMD. Hence, γ-MN may be suggested as a new candidate for cholestatic patients.

α-Mangostin Promotes In Vitro and In Vivo Degradation of Androgen Receptor and AR-V7 Splice Variant in Prostate Cancer Cells

A major limitation of current prostate cancer pharmacotherapy approaches is the inability of these compounds to target androgen receptor variants or mutants that develop during prostate cancer progression. The demand for novel therapeutics to prevent, slow, and treat prostate cancer is significant because FDA approved anti-androgens are associated with adverse events and can eventually drive drug-resistant prostate cancer. This study evaluated α-mangostin for its novel ability to degrade the androgen receptor and androgen receptor variants. α-Mangostin is one of more than 70 isoprenylated xanthones isolated from Garcinia mangostana that we have been evaluating for their anticancer potential. Prostate cancer cells treated with α-mangostin exhibited decreased levels of wild-type and mutated androgen receptors. Immunoblot, immunoprecipitation, and transfection experiments demonstrated that the androgen receptor was ubiquitinated and subsequently degraded via the proteasome, which we hypothesize occurs with the assistance of BiP, an ER chaperone protein that we have shown to associate with the androgen receptor. We also evaluated α-mangostin for its antitumor activity and promotion of androgen receptor degradation in vivo. In summary, our study demonstrates that androgen receptor degradation occurs through the novel activation of BiP and suggests a new therapeutic approach for prostate cancer.

Mangosteen for malignancy prevention and intervention: Current evidence, molecular mechanisms, and future perspectives

Mangosteen (Garcinia mangostana L.), also known as the "queen of fruits", is a tropical fruit of the Clusiacea family. While native to Southeast Asian countries, such as Thailand, Indonesia, Malaysia, Myanmar, Sri Lanka, India, and the Philippines, the fruit has gained popularity in the United States due to its health-promoting attributes. In traditional medicine, mangosteen has been used to treat a variety of illnesses, ranging from dysentery to wound healing. Mangosteen has been shown to exhibit numerous biological and pharmacological activities, such as antioxidant, anti-inflammatory, antibacterial, antifungal, antimalarial, antidiabetic, and anticancer properties. Disease-preventative and therapeutic properties of mangosteen have been ascribed to secondary metabolites called xanthones, present in several parts of the tree, including the pericarp, fruit rind, peel, stem bark, root bark, and leaf. Of the 68 mangosteen xanthones identified so far, the most widely-studied are α-mangostin and γ-mangostin. Emerging studies have found that mangosteen constituents and phytochemicals exert encouraging antineoplastic effects against a myriad of human malignancies. While there are a growing number of individual research papers on the anticancer properties of mangosteen, a complete and critical evaluation of published experimental findings has not been accomplished. Accordingly, the objective of this work is to present an in-depth analysis of the cancer preventive and anticancer potential of mangosteen constituents, with a special emphasis on the associated cellular and molecular mechanisms. Moreover, the bioavailability, pharmacokinetics, and safety of mangosteen-derived agents together with current challenges and future research avenues are also discussed.

Design, Synthesis, Biological Evaluation, and Preliminary Mechanistic Study of a Novel Mitochondrial-Targeted Xanthone

α-Mangostin, a natural xanthone, was found to have anticancer effects, but these effects are not sufficient to be effective. To increase anticancer potential and selectivity, a triphenylphosphonium cation moiety (TPP) was introduced to α-mangostin to specifically target cancer cell mitochondria. Compared to the parent compound, the cytotoxicity of the synthesized compound 1b increased by one order of magnitude. Mechanistic analysis revealed that the anti-tumor effects were involved in the mitochondrial apoptotic pathway by prompting apoptosis and arresting the cell cycle at the G0/G1 phase, increasing the production of reactive oxygen species (ROS), and reducing mitochondrial membrane potential (Δψ_m). More notably, the antitumor activity of compound 1b was further confirmed by zebrafish models, which remarkably inhibited cancer cell proliferation and migration, as well as zebrafish angiogenesis. Taken together, our results for the first time indicated that TPP-linked 1b could lead to the development of new mitochondrion-targeting antitumor agents.

Anti-Acanthamoeba activity of a semi-synthetic mangostin derivative and its ability in removal of Acanthamoeba triangularis WU19001 on contact lens

Garcinia mangostana L., also known as the mangosteen tree, is a native medicinal plant in Southeast Asia having a wide variety of pharmacologically active compounds, including xanthonoid mangostin. In this study, we examined the pharmacological activities of the selected semi-synthetic mangostin derivative, namely, amoebicidal activity, encystation inhibition, excystation activity, and removal capacity of adhesive Acanthamoeba from the surface of contact lens (CL). Among the three derivatives, C1 exhibited promising anti-Acanthamoeba activity against Acanthamoeba triangularis WU19001 trophozoites and cysts. SEM images displayed morphological changes in Acanthamoeba trophozoites, including the loss of acanthopodia, pore formation in the cell membrane, and membrane damage. In addition, the treated cyst was shrunken and adopted an irregular flat cyst shape. Under a fluorescence microscope, acridine orange and propidium iodide (AO/PI) staining revealed C1 induced condensation of cytoplasm and chromatin with the loss of cell volume in the treated trophozoites, while calcofluor white staining demonstrated the leakage of cell wall in treated cysts, leading to cell death. Interestingly, at the concentration ranges in which C1 showed the anti-Acanthamoeba effects (IC₅₀ values ranging from 0.035-0.056 mg/mL), they were not toxic to Vero cells. C1 displayed the highest inhibitory effect on A. triangularis encystation at 1/16×MIC value (0.004 mg/mL). While C1 demonstrated the excystation activity at 1/128×MIC value with a high rate of 89.47%. Furthermore, C1 exhibited the removal capacity of adhesive Acanthamoeba from the surface of CL comparable with commercial multipurpose solutions (MPSs). Based on the results obtained, C1 may be a promising lead agent to develop a therapeutic for the treatment of Acanthamoeba infections and disinfectant solutions for CL.

Mangosteen Metabolites as Promising Alpha-Amylase Inhibitor Candidates: In Silico and In Vitro Evaluations

Diabetes is a chronic metabolic disorder characterized by raised glucose levels in the blood, resulting in grave damage over time to various body organs, including the nerves, heart, kidneys, eyes, and blood vessels. One of its therapeutic treatment approaches involves the inhibition of enzymes accountable for carbohydrate digestion and absorption. The present work is aimed at evaluating the potential of some reported metabolites from Garcinia mangostana (mangosteen, Guttiferae) as alpha-amylase inhibitors. Forty compounds were assessed for their capacity to inhibit alpha-amylase using in silico studies as well as in vitro assays. Molecular docking was carried out to analyze their binding capacities in the 3D structure of alpha-amylase (PDB ID: 4GQR). Among the tested compounds, 6-O-β-D-glucopyranosyl-2,4,6,3',4',6'-hexahydroxybenzophenone (8), aromadendrin-8-C-glucoside (5), epicatechin (6), rhodanthenone (4), and garcixanthone D (40) had a high XP G.score and a Glide G.score of -12.425, -11.855, -11.135, and -11.048 Kcal/mol, respectively. Compound 8 possessed the XP and Glide docking score of -12.425 Kcal/mol compared to the reference compounds myricetin and acarbose which had an XP and Glide docking score of -12.319 and 11.201 Kcal/mol, respectively. It interacted through hydrogen bond formations between its hydroxyl groups and the residues His 101, Asp 197, Glu 233, Asp 300, and His 305, in addition to water bridges and hydrophobic interactions. Molecular mechanics-generalized born surface area (MM-GBSA) was used to calculate the binding free energy and molecular dynamic studies that indicated the stability of the alpha-amylase-compound 8 complex during the 100 ns simulation in comparison with myricetin- and acarbose-alpha-amylase complexes. Additionally, the in vitro alpha-amylase inhibition assay findings validated the in silico study's findings. This could further validate the potential of G. mangostana as a candidate for diabetes management.

Alpha Mangostin and Cisplatin as Modulators of Exosomal Interaction of Ovarian Cancer Cell with Fibroblasts

The diversity of exosomes and their role in the microenvironment make them an important point of interest in the development of cancer. In our study, we evaluated the effect of exosomes derived from ovarian cancer cells on gene expression in fibroblasts, including genes involved in metastasis. We also attempted to evaluate the indirect effect of cisplatin and/or α-mangostin on metastasis. In this aspect, we verified the changes induced by the drugs we tested on vesicular transfer associated with the release of exosomes by cells. We isolated exosomes from ovarian cancer cells treated and untreated with drugs, and then normal human fibroblasts were treated with the isolated exosomes. Changes in the expression of genes involved in the metastasis process were then examined. In our study, we observed altered expression of genes involved in various steps of the metastasis process (including genes related to cell adhesion, genes related to the interaction with the extracellular matrix, the cell cycle, cell growth and proliferation, and apoptosis). We have shown that α-mangostin and/or cisplatin, as chemotherapeutic agents, not only directly affect tumor cells but may also indirectly (via exosomes) contribute to delaying metastasis development.

Garcinone C Suppresses Tumorsphere Formation and Invasiveness by Hedgehog/Gli1 Signaling in Colorectal Cancer Stem-like Cells

Hyperactivation of hedgehog signaling occurs in colorectal cancer stem-like cells (CSCs), a rare subpopulation, potentially involved in metastasis, chemotherapy resistance, and cancer relapse. Garcinone C, a xanthone isolated from mangosteen (Garcinia mangostana), suppresses colorectal cancer in vivo and in vitro by inhibiting Gli1-dependent noncanonical hedgehog signaling. Herein, we investigated the effect of garcinone C on cancer stemness and invasiveness in colorectal cancer; Gli1 was noted as pivotal in maintaining stemness and invasiveness in HCT116 and HT29 CSCs. Garcinone C inhibited the proliferation and self-renewal of HCT116 and HT29 CSCs. Colon cancer stemness markers such as CD44, CD133, ALDH1, and Nanog were significantly decreased by garcinone C. Computational studies showed that garcinone C showed a high affinity with the Gli1 protein ZF domain by forming hydrogen bonds with amino acid residues of ASP244, ARG223, and ASP216. Besides, MG132 blocked the effects of garcinone C on Gli1. Thus, garcinone C suppressed colorectal CSCs by binding to Gli1 and enhancing its degradation. MMP2 and MMP9 levels, invasive-related markers, were increased in HCT116 CSCs but decreased by garcinone C. E-cadherin level was reduced in HCT116 CSCs, while the presence of garcinone C was restored. Garcinone C inhibited the proliferation and invasiveness of colorectal CSCs by targeting Gli1-dependent Hh signaling. Garcinone C may be a potent natural agent against colorectal cancer relapse.

The Effect of α-Mangostin and Cisplatin on Ovarian Cancer Cells and the Microenvironment

Ovarian cancer is one of the cancers that, unfortunately, is detected at a late stage of development. The current use of treatment has many side effects. Notably, up to 20% of patients show cisplatin resistance. We assess the effects of cisplatin and/or α-mangostin, a natural plant derivative, on ovarian cancer cells and on the cancer cell microenvironment. The effect of cisplatin and/or α-mangostin on the following cells of ovarian cancer lines: A2780, TOV-21G, and SKOV-3 was verified using the XTT cytotoxicity assay. The separate and combined effects of tested drugs on ovarian cancer cell viability were assessed. We assessed the influence of chemotherapeutic agents on the possibility of modulating the microenvironment. For this purpose, we isolated exosomes from drug-treated and untreated ovarian cancer cells. We estimated the differences in the amounts of exosomes released from cancer cells (NTA technique). We also examined the effects of isolated exosome fractions on normal human cells (NHDF human fibroblast line). In the present study, we demonstrate that treatment of A2780, SKOV-3, and TOV-21G cells with α-mangostin in combination with cisplatin can allow a reduction in cisplatin concentration while maintaining the same cytotoxic effect. Ovarian cancer cells release a variable number of exosomes into the microenvironment when exposed to α-mangostin and/or cisplatin. However, it is important to note that the cargo carried by exosomes released from drug-treated cells may be significantly different.