A study on dispersion and characterisation of α-mangostin loaded pH sensitive microgel systems

Occurrence analysis of alpha-mangostin from different organs of Garcinia mangostana L

Alpha-mangostin (AM) is a naturally occurring xanthone with remarkable pharmacological properties, including anti-inflammatory, anti-bacterial, and antioxidant effects. The compound is commonly extracted from the pericarps of Garcinia mangostana L. fruits, but its seasonal availability is limited. Investigating the potential of using various organs of the tree for AM extraction can help mitigate limitations imposed by the seasonal availability of fruits. This study employs the Soxhlet extraction method and gravitational column chromatography for the preparation of AM from various plant organs. The purity of the compound in the extract was quantitatively determined using high-performance liquid chromatography analysis. The stem barks demonstrated the highest yield at 1.3%, with a concentration of 324.593 µg/mL and a purity of 95.215% for AM. The finding is expected to assist in uncovering alternative sources of AM and contribute to sustainable utilisation of the tree, as various plant organs could be employed in AM extraction.

Nanoformulations of α-Mangostin for Cancer Drug Delivery System

Natural compounds are emerging as effective agents for the treatment of malignant diseases. The active constituent of α-mangostin from the pericarp of Garcinia mangostana L. has earned significant interest as a plant base compound with anticancer properties. Despite α-mangostin's superior properties as an anticancer agent, its applications are limited due to its poor solubility and physicochemical stability, rapid systemic clearance, and low cellular uptake. Our review aimed to summarize and discuss the nanoparticle formulations of α-mangostin for cancer drug delivery systems from published papers recorded in Scopus, PubMed, and Google Scholar. We investigated various types of α-mangostin nanoformulations to improve its anticancer efficacy by improving bioavailability, cellular uptake, and localization to specific areas These nanoformulations include nanofibers, lipid carrier nanostructures, solid lipid nanoparticles, polymeric nanoparticles, nanomicelles, liposomes, and gold nanoparticles. Notably, polymeric nanoparticles and nanomicelles can increase the accumulation of α-mangostin into tumors and inhibit tumor growth in vivo. In addition, polymeric nanoparticles with the addition of target ligands can increase the cellular uptake of α-mangostin. In conclusion, nanoformulations of α-mangostin are a promising tool to enhance the cellular uptake, accumulation in cancer cells, and the efficacy of α-mangostin as a candidate for anticancer drugs.

Multifunctional cellulosic nanofiber film with enhanced antimicrobial and anticancer properties by incorporation of ethanolic extract of Garcinia mangostana peel

Natural polymeric nanofibers-based materials for medical application is an intensive research area due to the unique features of natural polymeric nanofibers. Bacterial nanocellulose (BC) films containing various concentrations of mangosteen (Garcinia mangostana) peel extract were prepared and evaluated as a multifunctional nanofiber film. The extract was absorbed into BC hydrogel and air dried to entrap the extract into nanofiber network. The resulting films contained about 3, 35, and 294 mg of total phenolic compounds and 2, 24, and 250 mg of α-mangostin per cm³ of the dried films. The film containing the highest phenolic compounds and α-mangostin performed the inhibitory effect to Staphylococcus epidermidis, Propionibacterium acnes, and Staphylococcus aureus. High anticancer activity against B16F10 melanoma and MCF-7 breast cancer cells having viabilities of 10 and 5%, respectively after 48 h were detected after the treatments with the film. However, the film had a low toxicity against normal fibroblast and keratinocyte cells with 41 and 99% viability, respectively. The research suggested that the prepared films were a multifunctional nanofiber films with antimicrobial and anticancer properties.

Mangosteen Pericarp and Its Bioactive Xanthones: Potential Therapeutic Value in Alzheimer's Disease, Parkinson's Disease, and Depression with Pharmacokinetic and Safety Profiles

Alzheimer's disease (AD), Parkinson's disease (PD), and depression are growing burdens for society globally, partly due to a lack of effective treatments. Mangosteen (Garcinia mangostana L.,) pericarp (MP) and its xanthones may provide therapeutic advantages for these disorders. In this review, we discuss potential therapeutic value of MP-derived agents in AD, PD, and depression with their pharmacokinetic and safety profiles. MP-derived agents have shown multifunctional effects including neuroprotective, antioxidant, and anti-neuroinflammatory actions. In addition, they target specific disease pathologies, such as amyloid beta production and deposition as well as cholinergic dysfunction in AD; α-synuclein aggregation in PD; and modulation of monoamine disturbance in depression. Particularly, the xanthone derivatives, including α-mangostin and γ-mangostin, exhibit potent pharmacological actions. However, low oral bioavailability and poor brain penetration may limit their therapeutic applications. These challenges can be overcome in part by administering as a form of MP extract (MPE) or using specific carrier systems. MPE and α-mangostin are generally safe and well-tolerated in animals. Furthermore, mangosteen-based products are safe for humans. Therefore, MPE and its bioactive xanthones are promising candidates for the treatment of AD, PD, and depression. Further studies including clinical trials are essential to decipher their efficacy, and pharmacokinetic and safety profiles in these disorders.

Apoptosis induction by α-mangostin-loaded nanoparticles in human cervical carcinoma cells

The compound α-mangostin (AMG) extracted from Garcinia mangostana L. has potent anticancer properties but its clinical application is limited because of its poor solubility. In this study, AMG-loaded nanoparticles (NMG) were synthesized using a new formula and their apoptosis activity against human cervical carcinoma (HeLa) cells was investigated in comparison with organic solvent-soluble AMG in free form. The NMG was successfully synthesized with a particle size of <50 nm, polydispersity index <0.3, and zeta potential of -35.2 mV. At a concentration of 10 μg/mL, AMG reduced cell survival by 60%, whereas NMG treatment resulted in >90% cell death (p < 0.05). The AMG- or NMG-treated cells also showed changes in the size and shape and exhibited enhanced intensity of blue-stained nuclei, as well as decreased cell density, especially in NMG-treated cells. After 24 h of incubation with AMG or NMG, the cells went through late apoptosis at a rate of approximately 34% in 20 μg/mL AMG treatment and 27% in 10 μg/mL NMG treatment (p < 0.05). Thus, HeLa cells underwent more pronounced cell death through apoptosis induction caused by the NMG treatment compared to that caused by AMG. Clearly, the new NMG improved AMG bioavailability while maintaining the desired activity.

α-Mangostin Hydrogel Film Based Chitosan–Alginate for Recurrent Aphthous Stomatitis

Many antiseptic drugs, local anaesthetics, and corticosteroids have been used for effective therapy of recurrent aphthous stomatitis (RAS). However, these drugs have harmful side effects. α-mangostin (α-M), a main compound of mangosteen (Garcinia mangostana L.) peel, has been known as a wound healing agent. In addition, hydrogel film as dressings designed to separate mucosal lesions from the oral environment, and improve the effectiveness of RAS therapy. The purpose of this study was to develop α-M hydrogel film based chitosan–alginate (ChAlg/α-M HF) for RAS. The in silico study by Discovery studio visualizer and AutoDock confirmed that hydrogen bonding between Ch, Alg, and α-M occurred. The results of physicochemical characterizations by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) indicated that the ChAlg/α-M HF had a lower crystalline form compared to pure α-M. In addition, ChAlg/α-M HF significantly improved the swelling ratio and tensile strength compared to that of ChAlg HF. Moreover, the existence of Alg increased the degradability of Ch, and closely related to the release of α-M from ChAlg HF. The in vitro release study confirmed that the release of α-M from ChAlg/α-M HF was the Fickian diffusion model. Finally, the mucoadhesive study revealed that ChAlg/α-M HF had a good mucoadhesive property. These results suggest that hydrogel film-based chitosan–alginate have the potential as carriers of α-M for RAS therapy.

Physicochemical properties of alpha-mangostin loaded nanomeulsions prepared by ultrasonication technique

Hypothesis

Alpha-mangostin (AMG) is a natural compound possessing strong antibacterial activity. Because of its poor water solubility, the formulations of AMG usually require high concentrations of solubilizers leading limitation for using in some clinical applications. Thus, the novel formulation of topical nanoemulsion (NE) containing AMG (AMG-NE) with optimal content of the oil phase and surfactants was developed.

Experiments

AMG was extracted, purified and used as an active ingredient of AMG-NE. Blank NEs (NEs without AMG) with varying in contents of the oil phase and surfactants and AMG-NE were prepared by the ultrasonication technique. They were investigated their physicochemical properties including antibacterial activity against Staphyloccocus aureus and Propionibacterium acnes (which is recently renamed as Cutibacterium acnes).

Findings

Blank NEs and AMG-NE had droplet size in a range of nanometer and negative value of zeta potential. The droplet size, polydispersity index and zeta potential of blank NEs were affected by formulation compositions and sonication intensities. AMG could be loaded into a representative Blank NE at a maximum concentration of 0.2% w/w and did not cause significant changes in physicochemical properties. AMG-NE showed the antibacterial activity against Staphyloccocus aureus and Propionibacterium acnes without toxicity to the skin cells. Therefore, AMG-NE had potential for using in a clinical study to investigate its efficacy and safety in patients.

Deciphering the Antibacterial Mode of Action of Alpha-Mangostin on Staphylococcus epidermidis RP62A Through an Integrated Transcriptomic and Proteomic Approach

Background: Alpha-mangostin (α-MG) is a natural xanthone reported to exhibit rapid bactericidal activity against Gram-positive bacteria, and may therefore have potential clinical application in healthcare sectors. This study sought to identify the impact of α-MG on Staphylococcus epidermidis RP62A through integrated advanced omic technologies. Methods: S. epidermidis was challenged with sub-MIC (0.875 μg/ml) of α-MG at various time points and the differential expression pattern of genes/proteins were analyzed in the absence and presence of α-MG using RNA sequencing and LC-MS/MS experiments. Bioinformatic tools were used to categorize the biological processes, molecular functions and KEGG pathways of differentially expressed genes/proteins. qRT-PCR was employed to validate the results obtained from these analyses. Results: Transcriptomic and proteomic profiling of α-MG treated cells indicated that genes/proteins affected by α-MG treatment were associated with diverse cellular functions. The greatest reduction in expression was observed in transcription of genes conferring cytoplasmic membrane integrity (yidC2, secA and mscL), cell division (ftsY and divlB), teichoic acid biosynthesis (tagG and dltA), fatty-acid biosynthesis (accB, accC, fabD, fabH, fabI, and fabZ), biofilm formation (icaA) and DNA replication and repair machinery (polA, polC, dnaE, and uvrA). Those with increased expression were involved in oxidative (katA and sodA) and cellular stress response (clpB, clpC, groEL, and asp23). The qRT-PCR analysis substantiated the results obtained from transcriptomic and proteomic profiling studies. Conclusion: Combining transcriptomic and proteomic methods provided comprehensive information about the antibacterial mode of action of α-MG. The obtained results suggest that α-MG targets S. epidermidis through multifarious mechanisms, and especially prompts that loss of cytoplasmic membrane integrity leads to rapid onset of bactericidal activity.

Taib AZ, Mohd Noor N, Mohd Said MI, Abu Bakar M, Mackeen MM. From the Front or Back Door? Quantitative analysis of direct and indirect extractions of α-mangostin from mangosteen (Garcinia mangostana)

The pulp and pericarp of mangosteen (Garcinia mangostana) fruit are popular food, beverage and health products whereby 60% of the fruit consist of the pericarp. The major metabolite in the previously neglected or less economically significant part of the fruit, the pericarp, is the prenylated xanthone α-mangostin. This highly bioactive secondary metabolite is typically isolated using solvent extraction methods that involve large volumes of halogenated solvents either via direct or indirect extraction. In this study, we compared the quantities of α-mangostin extracted using three different extraction methods based on the environmentally friendly solvents methanol and ethyl acetate. The three solvent extractions methods used were direct extractions from methanol (DM) and ethyl acetate (DEA) as well as indirect extraction of ethyl acetate obtained via solvent partitioning from an initial methanol extract (IEA). Our results showed that direct extraction afforded similar and higher quantities of α-mangostin than indirect extraction (DM: 318 mg; DEA: 305 mg; IEA: 209 mg per 5 g total dried pericarp). Therefore, we suggest that the commonly used method of indirect solvent extraction using halogenated solvents for the isolation of α-mangostin is replaced by single solvent direct extraction using the environmentally friendly solvents methanol or ethyl acetate.

Mangosteen pericarp extract embedded in electrospun PVP nanofiber mats: physicochemical properties and release mechanism of α-mangostin

Background

α-Mangostin is a major active compound of mangosteen (Garcinia mangostana L.) pericarp extract (MPE) that has potent antioxidant activity. Unfortunately, its poor aqueous solubility limits its therapeutic application. Purpose: This paper reports a promising approach to improve the clinical use of this substance through electrospinning technique.

Methods

Polyvinylpyrrolidone (PVP) was explored as a hydrophilic matrix to carry α-mangostin in MPE. Physicochemical properties of MPE:PVP nanofibers with various extract-to-polymer ratios were studied, including morphology, size, crystallinity, chemical interaction, and thermal behavior. Antioxidant activity and the release of α-mangostin, as the chemical marker of MPE, from the resulting fibers were investigated.

Results

It was obtained that the MPE:PVP nanofiber mats were flat, bead-free, and in a size range of 387–586 nm. Peak shifts in Fourier-transform infrared spectra of PVP in the presence of MPE suggested hydrogen bond formation between MPE and PVP. The differential scanning calorimetric study revealed a noticeable endothermic event at 119°C in MPE:PVP nanofibers, indicating vaporization of moisture residue. This confirmed hygroscopic property of PVP. The absence of crystalline peaks of MPE at 2θ of 5.99°, 11.62°, and 13.01° in the X-ray diffraction patterns of electrospun MPE:PVP nanofibers showed amorphization of MPE by PVP after being electrospun. The radical scavenging activity of MPE:PVP nanofibers exhibited lower IC₅₀ value (55–67 µg/mL) in comparison with pure MPE (69 µg/mL). The PVP:MPE nanofibers tremendously increased the antioxidant activity of α-mangostin as well as its release rate. Applying high voltage in electrospinning process did not destroy the chemical structure of α-mangostin as indicated by retained in vitro antioxidant activity. The release rate of α-mangostin significantly increased from 35% to over 90% in 60 minutes. The release of α-mangostin from MPE:PVP nanofibers was dependent on α-mangostin concentration and particle size, as confirmed by the first-order kinetic model as well as the Hixson–Crowell kinetic model.

Conclusion

We successfully synthesized MPE:PVP nanofiber mats with enhanced antioxidant activity and release rate, which can potentially improve the therapeutic effects offered by MPE.

Nonpeptidic Amphiphilic Xanthone Derivatives: Structure-Activity Relationship and Membrane-Targeting Properties

We recently reported the bioinspired synthesis of a highly potent nonpeptidic xanthone, 2c (AM-0016), with potent antibacterial activity against MRSA. Herein, we report a thorough structure-activity relationship (SAR) analysis of a series of nonpeptidic amphiphilic xanthone derivatives in an attempt to identify more potent compounds with lower hemolytic activity and greater membrane selectivity. Forty-six amphiphilic xanthone derivatives were analyzed in this study and structurally classified into four groups based on spacer length, cationic moieties, lipophilic chains, and triarm functionalization. We evaluated and explored the effects of the structures on their membrane-targeting properties. The SAR analysis successfully identified 3a with potent MICs (1.56-3.125 μ/mL) and lower hemolytic activity (80.2 μg/mL for 3a versus 19.7 μg/mL for 2c). Compound 3a displayed a membrane selectivity of 25.7-50.4. Thus, 3a with improved HC50 value and promising selectivity could be used as a lead compound for further structural optimization for the treatment of MRSA infection.

Physicochemical properties and anti-Propionibacterium acnes activity of film-forming solutions containing alpha-mangostin-rich extract

The objective of this study was to study the effect of formulation compositions on physicochemical properties and anti-Propionibacterium acnes activity of film-forming solutions containing alpha-mangostin-rich extract (AM). Film-forming solution bases and film-forming solutions containing AM were prepared by using Eudragit RL PO or Klucel LF or combinations of them as film-forming polymers. Rheological properties, pH values of the solutions, and mechanical properties of the dry films were investigated. An optimized formulation was selected and evaluated for the film surface, in vitro AM release, an anti-P. acnes activity, and potential for being a skin irritant. It was found that mechanical properties of the dry films were affected by total polymer contents, ratios of Klucel LF/Eudragit RL PO, AM, and contents of triethyl citrate. The film-forming solutions containing AM had pH values around 7.0. Their flow curves exhibited Newtonian flow behaviors. The optimized formulation provided films possessing smooth and nonporous surfaces. These films showed greater anti-P. acnes activity than their base films without toxicity to skin fibroblasts. Furthermore, AM released from the film matrix obeyed Higuchi's equation. In conclusion, the film-forming solutions containing AM had potential for treatment of acne vulgaris caused by P. acnes. However, further in vivo study is necessary to determine their efficacy and safety for using in patients suffering from acne vulgaris.