Acute toxicity and teratogenicity of α-mangostin in zebrafish embryos

Inhibition of Seizure-Like Paroxysms and Toxicity Effects of Securidaca longepedunculata Extracts and Constituents in Zebrafish Danio rerio

Plants used in traditional medicine in the management of epilepsy could potentially yield novel drug compounds with antiepileptic properties. The medicinal plant Securidaca longepedunculata is widely used in traditional medicine in the African continent, and epilepsy is among several indications. Limited knowledge is available on its toxicity and medicinal effects, such as anticonvulsant activities. This study explores the potential in vivo inhibition of seizure-like paroxysms and toxicity effects of dichloromethane (DCM) and ethanol (EtOH) extracts, as well as isolated xanthones and benzoates of S. longepedunculata. Ten phenolic compounds were isolated from the DCM extract. All of the substances were identified by nuclear magnetic resonance spectroscopy. Assays for toxicity and inhibition of pentylenetetrazole (PTZ)-induced seizure-like paroxysms were performed in zebrafish larvae. Among the compounds assessed in the assay for maximum tolerated concentration (MTC), benzyl-2-hydroxy-6-methoxy-benzoate (MTC 12.5 μM), 4,8-dihydroxy-1,2,3,5,6-pentamethoxyxanthone (MTC 25 μM), and 1,7-dihydroxy-4-methoxyxanthone (MTC 6.25 μM) were the most toxic. The DCM extract, 1,7-dihydroxy-4-methoxyxanthone and 2-hydroxy-1,7-dimethoxyxanthone displayed the most significant inhibition of paroxysms by altering the locomotor behavior in GABAA receptor antagonist, PTZ, which induced seizures in larval zebrafish. The EtOH extract, benzyl benzoate, and benzyl-2-hydroxy-6-methoxy-benzoate unexpectedly increased locomotor activity in treated larval zebrafish and decreased locomotor activity in nontreated larval zebrafish, seemingly due to paradoxical excitation. The results reveal promising medicinal activities of this plant, contributing to our understanding of its use as an antiepileptic drug. It also shows us the presence of potentially new lead compounds for future drug development.

Multi-target modulation of ion channels underlying the analgesic effects of α-mangostin in dorsal root ganglion neurons

BACKGROUND

α-Mangostin is a xanthone isolated from the pericarps of mangosteen fruit with, and has analgesic properties. Although the effects suggest an interaction of α-mangostin with ion channels in the nociceptive neurons, electrophysiological investigation of the underlying mechanism has not been performed.

HYPOTHESIS

We hypothesized that α-Mangostin exerts its analgesic effects by modulating the activity of various ion channels in dorsal root ganglion (DRG) neurons.

METHODS

We performed a whole-cell patch clamp study using mouse DRG neurons, HEK293T cells overexpressing targeted ion channels, and ND7/23 cells. Molecular docking (MD) and in silico absorption, distribution, metabolism, and excretion (ADME) analyses were conducted to obtain further insights into the binding sites and pharmacokinetics, respectively.

RESULTS

Application of α-mangostin (1-3 µM) hyperpolarized the resting membrane potential (RMP) of small-sized DRG neurons by increasing background K⁺ conductance and thereby inhibited action potential generation. At micromolar levels, α-mangostin activates TREK-1, TREK-2, or TRAAK, members of the two-pore domain K⁺ channel (K2P) family known to be involved in RMP formation in DRG neurons. Furthermore, capsaicin-induced TRPV1 currents were potently inhibited by α-mangostin (0.43 ± 0.27 µM), and partly suppressed tetrodotoxin-sensitive voltage-gated Na⁺ channel (Na_V) currents. MD simulation revealed that multiple oxygen atoms in α-mangostin may form stable hydrogen bonds with TREKs, TRAAK, TRPV1, and Na_V channels. In silico ADME tests suggested that α-mangostin may satisfy the drug-likeness properties without penetrating the blood-brain barrier.

CONCLUSION

The analgesic properties of α-mangostin might be mediated by the multi-target modulation of ion channels, including TREK/TRAAK activation, TRPV1 inhibition, and reduction of the tetrodotoxin-sensitive Na_V current. The findings suggest that the phytochemical can be a multi-ion channel-targeting drug and an alternative drug for effective pain management.

Nanopolyphenol rejuvenates microglial surveillance of multiple misfolded proteins through metabolic reprogramming

Microglial surveillance plays an essential role in clearing misfolded proteins such as amyloid-beta, tau, and α-synuclein aggregates in neurodegenerative diseases. However, due to the complex structure and ambiguous pathogenic species of the misfolded proteins, a universal approach to remove the misfolded proteins remains unavailable. Here, we found that a polyphenol, α-mangostin, reprogrammed metabolism in the disease-associated microglia through shifting glycolysis to oxidative phosphorylation, which holistically rejuvenated microglial surveillance capacity to enhance microglial phagocytosis and autophagy-mediated degradation of multiple misfolded proteins. Nanoformulation of α-mangostin efficiently delivered α-mangostin to microglia, relieved the reactive status and rejuvenated the misfolded-proteins clearance capacity of microglia, which thus impressively relieved the neuropathological changes in both Alzheimer's disease and Parkinson's disease model mice. These findings provide direct evidences for the concept of rejuvenating microglial surveillance of multiple misfolded proteins through metabolic reprogramming, and demonstrate nanoformulated α-mangostin as a potential and universal therapy against neurodegenerative diseases.

Botanical characteristics, chemical components, biological activity, and potential applications of mangosteen

Garcinia mangostana L. (Mangosteen), a functional food, belongs to the Garcinaceae family and has various pharmacological effects, including anti-oxidative, anti-inflammatory, anticancer, antidiabetic, and neuroprotective effects. Mangosteen has abundant chemical constituents with powerful pharmacological effects. After searching scientific literature databases, including PubMed, Science Direct, Research Gate, Web of Science, VIP, Wanfang, and CNKI, we summarized the traditional applications, botanical features, chemical composition, and pharmacological effects of mangosteen. Further, we revealed the mechanism by which it improves health and treats disease. These findings provide a theoretical basis for mangosteen's future clinical use and will aid doctors and researchers who investigate the biological activity and functions of food.

The utilization of mangosteen pericarp extract for anticoccidial drug replacement in broiler feed

The use of anticoccidial drugs in broilers has led to concerns, especially the drug residues in meat and the occurrence of drug resistance. This study aimed to extract, standardize, quantify and utilize mangosteen pericarp extract (MPE) containing α-mangostin as a replacement for anticoccidial drugs in broiler feed. The pericarp was acquired from different areas of Thailand and used for extraction and standardization. The antioxidant activity of the extract was evaluated. The extract was formulated into granules, and the flowability and stability of the granules were assessed. The MPE formulation was added to the broiler feed and then fed to the broilers that were infected with Eimeria tenella. The growth rate and intestinal lesion score (post-mortem) of the broilers were assessed. The pericarp obtained passed the identification test and phytochemical analyses. The active compound, α-mangostin, was best extracted using 95% ethanol. The MPE had superior antioxidant activity compared to standard antioxidants. Granules of the extract formulated with Avicel® PH102 provided desirable flowability and stability. The broilers fed with the feed containing 500 mg/kg α-mangostin showed a similar growth rate and post-mortem lesion score compared with the control group and those that received feed containing 60 mg/kg salinomycin. Our findings demonstrated that MPE with a high content of the active compound could be developed and used in place of anticoccidial drugs in the broiler feed.

The metabolic and molecular mechanisms of α‑mangostin in cardiometabolic disorders (Review)

α-mangostin is a xanthone predominantly encountered in Garcinia mangostana. Extensive research has been carried out concerning the effects of this compound on various diseases, including obesity, cancer and metabolic disorders. The present review suggests that α-mangostin exerts promising anti-obesity, hepatoprotective, antidiabetic, cardioprotective, antioxidant and anti-inflammatory effects on various pathways in cardiometabolic diseases. The anti-obesity effects of α-mangostin include the reduction of body weight and adipose tissue size, the increase in fatty acid oxidation, the activation of hepatic AMP-activated protein kinase and Sirtuin-1, and the reduction of peroxisome proliferator-activated receptor γ expression. Hepatoprotective effects have been revealed, due to reduced fibrosis through transforming growth factor-β 1 pathways, reduced apoptosis and steatosis through reduced sterol regulatory-element binding proteins expression. The antidiabetic effects include decreased fasting blood glucose levels, improved insulin sensitivity and the increased expression of GLUT transporters in various tissues. Cardioprotection is exhibited through the restoration of cardiac functions and structure, improved mitochondrial functions, the promotion of M2 macrophage populations, reduced endothelial and cardiomyocyte apoptosis and fibrosis, and reduced acid sphingomyelinase activity and ceramide depositions. The antioxidant effects of α-mangostin are mainly related to the modulation of antioxidant enzymes, the reduction of oxidative stress markers, the reduction of oxidative damage through a reduction in Sirtuin 3 expression mediated by phosphoinositide 3-kinase/protein kinase B/peroxisome proliferator-activated receptor-γ coactivator-1α signaling pathways, and to the increase in Nuclear factor-erythroid factor 2-related factor 2 and heme oxygenase-1 expression levels. The anti-inflammatory effects of α-mangostin include its modulation of nuclear factor-κB related pathways, the suppression of mitogen-activated protein kinase activation, increased macrophage polarization to M2, reduced inflammasome occurrence, increased Sirtuin 1 and 3 expression, the reduced expression of inducible nitric oxide synthase, the production of nitric oxide and prostaglandin E2, the reduced expression of Toll-like receptors and reduced proinflammatory cytokine levels. These effects demonstrate that α-mangostin may possess the properties required for a suitable candidate compound for the management of cardiometabolic diseases.

Lactate metabolism in rheumatoid arthritis: Pathogenic mechanisms and therapeutic intervention with natural compounds

BACKGROUND

Rheumatoid arthritis (RA) is a common chronic and systemic autoimmune disease characterized by persistent inflammation and hyperplasia of the synovial membrane, the degradation of cartilage, and the erosion of bones in diarthrodial joints. The inflamed joints of patients with RA have been recognized to be a site of hypoxic microenvironment which results in an imbalance of lactate metabolism and the accumulation of lactate. Lactate is no longer considered solely a metabolic waste product of glycolysis, but also a combustion aid in the progression of RA from the early stages of inflammation to the late stages of bone destruction.

PURPOSE

To review the pathogenic mechanisms of lactate metabolism in RA and investigate the potential of natural compounds for treating RA linked to the regulation of imbalance in lactate metabolism.

METHODS

Research advances in our understanding of lactate metabolism in the pathogenesis of RA and novel pharmacological approaches of natural compounds by targeting lactate metabolic signaling were comprehensively reviewed and deeply discussed.

RESULTS

Lactate produced by RA synovial fibroblasts (RASFs) acts on targeted cells such as T cells, macrophages, dendritic cells and osteoclasts, and affects their differentiation, activation and function to accelerate the development of RA. Many natural compounds show therapeutic potential for RA by regulating glycolytic rate-limiting enzymes to limit lactate production, and affecting monocarboxylate transporter and acetyl-CoA carboxylase to inhibit lactate transport and conversion.

CONCLUSION

Regulation of imbalance in lactate metabolism offers novel therapeutic approaches for RA, and natural compounds capable of targeting lactate metabolic signaling constitute potential candidates for development of drugs RA.

Developmental effects of sesamolin on zebrafish (Danio rerio) embryos

Sesamolin is one of the major active compounds found in sesame seeds (Sesamum indicum L.) that are commonly and increasingly used as an ingredient in cuisines and various food products. The compound has been reported to have several pharmaceutical activities such as antioxidant, antimicrobial, neuroprotective, and anticancer. However, the toxicological profile of sesamolin does not currently include developmental toxicity. In this study, we assessed sesamolin toxicity to embryonic development of zebrafish by exposure for 72 h at concentrations ranging from 10 to 50 μM. The evaluation revealed that sesamolin did not affect survival and hatching rates. However, it did induce embryo malformations and reduced embryonic heart rates in a dose-dependent manner. By qRT-PCR analysis, it downregulated the expression of oxidative stress-related genes, including superoxide dismutase 1 (sod1), catalase (cat), and glutathione S-transferase pi 2 (gstp2). Alkaline phosphatase staining of embryos revealed that sesamolin inhibited the development of subintestinal vessels, and hemoglobin staining revealed a negative impact on embryonic erythropoiesis. These findings showed that sesamolin affected genes related to angiogenesis and erythropoiesis. The risks of sesamolin to embryonic development found in this study may imply similar effects in humans and other mammals.

The diverse bioactivity of α-mangostin and its therapeutic implications

α-Mangostin is a xanthone natural product isolated as a secondary metabolite from the mangosteen tree. It has attracted a great deal of attention due to its wide-ranging effects on certain biological activity, such as apoptosis, tumorigenesis, proliferation, metastasis, inflammation, oxidation, bacterial growth and metabolism. This review focuses on the key pathways directly affected by α-mangostin and how this varies between disease states. Insight is also provided, where investigated, into the key structural features of α-mangostin that produce these biological effects. The review then sheds light on the utility of α-mangostin as a investigational tool for certain diseases and demonstrate how future derivatives may increase selectivity and potency for specific disease states.

α-mangostin preserves hepatic microvascular architecture in fibrotic rats as shown by scanning electron microscopy of vascular corrosion casts

Liver fibrosis is a dynamic condition caused by wound-healing in which scar tissue replaces the liver parenchyma following repetitive injuries. It is hypothesized that α-mangostin (AM), the major constituent of the xanthone fraction in extracts of Garcinia mangostana L., may protect the hepatic microvascular bed from thioacetamide (TAA)-induced fibrosis. In the present study, rats were divided into 4 groups: Control rats received no treatment; TAA-treated rats received 150 mg/kg TAA 3 times per week intraperitoneally; AM-treated rats received 75 mg/kg AM twice per week intraperitoneally; and TAA+AM-treated rats received both TAA and AM as described above. Rat livers were processed either for light microscopy or for vascular corrosion casting after 30 and 60 days of treatment. Vascular parameters were measured by 3D morphometry analysis of scanning electron micrographs. AM attenuated hepatocellular injuries and delayed both periportal and pericentral fibrosis in the TAA-treated rats. The comparison of findings at day 30 and 60 showed that TAA-induced fibrotic changes were progressive in time, and that the beneficial effects of AM only became apparent after prolonged treatment. The livers of rats treated with both TAA and AM had less space surrounding the portal vessels, improved preservation of the hepatic microvascular pattern, and minimally altered sinusoidal patterns with few signs of terminal portal venule remodeling. AM therefore partially protected the liver against hepatotoxin-induced fibrosis and the associated microvascular changes. The mechanism of the protective effect of AM on the liver remains to be investigated.

Effects of α-mangostin on embryonic development and liver development in zebrafish

Background

Alpha-mangostin has potential as a chemopreventive agent but there is little information on its toxicological profile and developmental toxicity.

Objective

We evaluated the effects of α-mangostin on embryonic development and hepatogenesis in zebrafish.

Result

Exposure of embryos to 0.25–4 μM α-mangostin from 4–120 h post-fertilization (hpf) caused mortality of embryos with LC50 1.48 ± 0.29 μM. The compound also caused deformities, including head malformation, pericardial oedema, absence of swim bladder, yolk oedema, and bent tail. Exposure of zebrafish embryos to α-mangostin during early hepatogenesis (16–72 hpf) decreased the transcript expression levels of liver fatty acid-binding protein 10a (Fabp10a), but increased gene markers of inflammation, oxidative stress, and apoptosis. In Fabp10a:DsRed transgenic zebrafish, the intensity and the area of fluorescence in the liver of the treated group were decreased (non-significantly) relative to controls.

Conclusion

These effects were more marked during early hepatogenesis (16–72 hpf) than during post-hepatogenesis (72–120 hpf).

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.