Activation of FXR by ganoderic acid A promotes remyelination in multiple sclerosis via anti-inflammation and regeneration mechanism

Ganoderic acid A mitigates dopaminergic neuron ferroptosis via inhibiting NCOA4-mediated ferritinophagy in Parkinson's disease mice

ETHNOPHARMACOLOGICAL RELEVANCE

Ganoderma lucidum, a renowned tonic traditional Chinese medicine, is widely recognized for the exceptional activity in soothing nerves and nourishing the brain. It has been extensively employed to alleviate various neurological disorders, notably Parkinson's disease (PD).

AIM OF THE STUDY

To appraise the antiparkinsonian effect of GAA, the main bioactive constituent of G. lucidum, and clarify the molecular mechanism through the perspective of ferritinophagy-mediated dopaminergic neuron ferroptosis.

MATERIALS AND METHODS

PD mouse and cell models were established using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium (MPP+), respectively. Cell viability, behavioral tests and immunofluorescence analysis were performed to evaluate the neurotoxicity, motor dysfunction and dopaminergic loss, respectively. Biochemical assay kits were used to determine the levels of iron, lipid reactive oxygen species (ROS), malondialdehyde (MDA), total ROS and glutathione (GSH). Western blot and immunofluorescence were applied to detect the expressions of nuclear receptor co-activator 4 (NCOA4), ferritin heavy chain 1 (FTH1), p62 and LC3B. Additionally, NCOA4-overexpressing plasmid vector was constructed to verify the inhibitory effect of GAA on the neurotoxicity and ferroptosis-related parameters in PD models.

RESULTS

GAA significantly mitigated MPP+/MPTP-induced neurotoxicity, motor dysfunction and dopaminergic neuron loss (p＜0.01 or p＜0.05). In contrast to MPP+/MPTP treatment, GAA treatment decreased the levels of iron, MDA, lipid and total ROS, while increasing the GSH level. GAA also reduced the levels of NCOA4 and LC3B, and enhanced the expressions of FTH1 and p62 in PD models (p＜0.01 or p＜0.05). However, the protective effect of GAA against the neurotoxicity, NCOA4-mediated ferritinophagy and ferroptosis in PD model was abolished by the overexpression of NCOA4 (p＜0.01).

CONCLUSION

GAA exerted a protective effect on PD, and this effect was achieved by suppressing dopaminergic neuron ferroptosis through the inhibition of NCOA4-mediated ferritinophagy.

Fuyuan decoction prevents nasopharyngeal carcinoma metastasis by inhibiting circulating tumor cells/ endothelial cells interplay and enhancing anti-cancer immune response

Distant metastasis is a major cause of treatment failure in cancer patients and a key challenge to improving cancer care today. We hypothesized that enhancing anti-cancer immune response and inhibiting circulating tumor cells (CTCs) adhesion and transendothelial migration through synergistic multi-target approaches may effectively prevent cancer metastasis. "Fuyuan Decoction" (FYD) is a traditional Chinese medicine compound that is widely used to prevent postoperative metastasis in cancer patients, but its underlying mechanism remains unclear. In this work, we systematically elucidated the underlying molecular mechanism by which FYD prevents cancer metastasis through multi-compound and multi-target synergies in vitro and in vivo. FYD significantly prevented cancer metastasis at non-cytotoxic concentrations by suppressing the adhesion of CTCs to endothelial cells and their subsequent transendothelial migration, as well as enhancing anti-cancer immune response. Mechanistically, FYD interrupts adhesion of CTCs to vascular endothelium by inhibiting TNF-α-induced CAMs expression via regulation of the NF-κB signaling pathway in endothelial cells. FYD inhibits invasion and migration of CTCs by suppressing EMT, PI3K/AKT and FAK signaling pathways. Moreover, FYD enhances the anti-cancer immune response by significantly increasing the population of Tc and NK cells in the peripheral immune system. In addition, the chemical composition of FYD was determined by UPLC-HRMS, and the results indicated that multiple compounds in FYD prevents cancer metastasis through multi-target synergistic treatment. This study provides a modern medical basis for the application of FYD in the prevention of cancer metastasis, and suggesting that multi-drug and multi-target synergistic therapy may be one of the most effective ways to prevent cancer metastasis.

Ganoderic Acid A: A Potential Natural Neuroprotective Agent for Neurological Disorders: A Review

Ganoderic acid A (GAA) is one of the major triterpenoids in Ganoderma lucidum (GL). Accumulating evidence has indicated that GAA demonstrates multiple pharmacological effects and exhibits treatment potential for various neurological disorders. Here, the effects and mechanisms of GAA in the treatment of neurological disorders were evaluated and discussed through previous research results. By summarizing previous research results, we found that GAA may play a neuroprotective role through various mechanisms: anti-inflammatory, anti-oxidative stress, anti-apoptosis, protection of nerve cells, and regulation of nerve growth factor. Therefore, GAA is a promising natural neuroprotective agent and this review would contribute to the future development of GAA as a novel clinical candidate drug for treating neurological diseases.

Innovative drug delivery strategies to the CNS for the treatment of multiple sclerosis

Disorders of the central nervous system (CNS), such as multiple sclerosis (MS) represent a great emotional, financial and social burden. Despite intense efforts, great unmet medical needs remain in that field. MS is an autoimmune, chronic inflammatory demyelinating disease with no curative treatment up to date. The current therapies mostly act in the periphery and seek to modulate aberrant immune responses as well as slow down the progression of the disease. Some of these therapies are associated with adverse effects related partly to their administration route and show some limitations due to their rapid clearance and inability to reach the CNS. The scientific community have recently focused their research on developing MS therapies targeting different processes within the CNS. However, delivery of therapeutics to the CNS is mainly limited by the presence of the blood-brain barrier (BBB). Therefore, there is a pressing need to develop new drug delivery strategies that ensure CNS availability to capitalize on identified therapeutic targets. Several approaches have been developed to overcome or bypass the BBB and increase delivery of therapeutics to the CNS. Among these strategies, the use of alternative routes of administration, such as the nose-to-brain (N2B) pathway, offers a promising non-invasive option in the scope of MS, as it would allow a direct transport of the drugs from the nasal cavity to the brain. Moreover, the combination of bioactive molecules within nanocarriers bring forth new opportunities for MS therapies, allowing and/or increasing their transport to the CNS. Here we will review and discuss these alternative administration routes as well as the nanocarrier approaches useful to deliver drugs for MS.

A Comprehensive Review on the Chemical Composition, Pharmacology and Clinical Applications of Ganoderma

Ganoderma is the dried fruiting bodiy of Ganoderma lucidum (Leyss.ex Fr.) Karst. or Ganoderma sinense Zhao, Xu et Zhang, belonging to the family Polyporaceae, which grows mainly in tropical, subtropical, and temperate regions. As a traditional Chinese medicine, Ganoderma has been used in China for more than 2000 years because of its medicinal properties, such as relieving cough and asthma, providing nourishment, and strengthening. Currently, more than 470 natural compounds have been obtained from the fungus, mainly including terpenoids, steroids, alkaloids, phenols, and other types of compounds. Modern pharmacological studies have shown that Ganoderma has antitumor, anti-inflammatory, hypoglycemic, hypolipidemic, and immunomodulatory effects. It is mainly used in clinical practice for the treatment of Diabetic Nephropathy and malignant tumors, with few side effects and high safety. This paper reviews the progress of research on its chemical composition, pharmacological effects, and clinical applications, with the goal of providing a basis for the better development and utilization of Ganoderma.

Germplasm resources and secondary metabolism regulation in Reishi mushroom (Ganoderma lucidum)

Ganoderma lucidum is a valuable medical macrofungus with a myriad of diverse secondary metabolites, in which triterpenoids are the major constituents. This paper introduced the germplasm resources of genus Ganoderma from textual research, its distribution and identification at the molecular level. Also we overviewed G. lucidum in the components, the biological activities and biosynthetic pathways of ganoderic acid, aiming to provide scientific evidence for the development and utilization of G. lucidum germplasm resources and the biosynthesis of ganoderic acid.

Farnesoid X receptor protects against lipopolysaccharide-induced endometritis by inhibiting ferroptosis and inflammatory response

Endometritis is an inflammatory condition that affects the endometrium; it is induced by bacterial infection and often leads to infertility and repeated abortions. Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that mediates a variety of inflammatory diseases. In the present study, we determined the protective effects of FXR on lipopolysaccharide (LPS)-induced endometritis in mice and the underlying mechanisms. The results showed that LPS administration reduced the expression of FXR in the uterus, and treatment with the FXR agonist GW4064 and fexaramine significantly alleviated the endometritis induced by LPS. In addition, compared with wild-type (WT) mice, FXR-knockout mice had more severe inflammatory responses in their uteri after LPS treatment. Moreover, ferroptosis was increased during LPS-induced endometritis, as shown by increased levels of malondialdehyde (MDA) and iron, and decreased levels of superoxide dismutase (SOD), glutathione (GSH), GXP4 and SLC7A11. In addition, inhibition of ferroptosis by treatment with ferrostation-1 (Fer-1) and liproxstatin (Lip-1) alleviated LPS-induced endometritis. Additionally, FXR-knockout mice were used to determine the relationship between FXR and ferroptosis. The results showed that knockout of FXR induced ferroptosis, and an FXR agonist inhibited LPS-induced ferroptosis. Finally, the regulatory effects of obeticholic acid (OCA) on FXR/ferroptosis and endometritis were assessed. The results showed that treatment with OCA increased the expression of FXR, decreased the levels of ferroptosis, and inhibited the endometritis induced by LPS. In conclusion, the results showed that activation of FXR can alleviate LPS-induced endometritis by inhibiting ferroptosis, and FXR may be a potential therapeutic target for treating endometritis.

Ganoderic Acid A and Its Amide Derivatives as Potential Anti-Cancer Agents by Regulating the p53-MDM2 Pathway: Synthesis and Biological Evaluation

The mechanisms of action of natural products and the identification of their targets have long been a research hotspot. Ganoderic acid A (GAA) is the earliest and most abundant triterpenoids discovered in Ganoderma lucidum. The multi-therapeutic potential of GAA, in particular its anti-tumor activity, has been extensively studied. However, the unknown targets and associated pathways of GAA, together with its low activity, limit in-depth research compared to other small molecule anti-cancer drugs. In this study, GAA was modified at the carboxyl group to synthesize a series of amide compounds, and the in vitro anti-tumor activities of the derivatives were investigated. Finally, compound A2 was selected to study its mechanism of action because of its high activity in three different types of tumor cell lines and low toxicity to normal cells. The results showed that A2 could induce apoptosis by regulating the p53 signaling pathway and may be involved in inhibiting the interaction of MDM2 and p53 by binding to MDM2 (K_D = 1.68 µM). This study provides some inspiration for the research into the anti-tumor targets and mechanisms of GAA and its derivatives, as well as for the discovery of active candidates based on this series.

The Dectin-1 Receptor Signaling Pathway Mediates the Remyelination Effect of Lentinan through Suppression of Neuroinflammation and Conversion of Microglia

Demyelinating diseases such as multiple sclerosis (MS) are chronic inflammatory autoimmune diseases and involve demyelination and axonal degeneration. Microglia rapidly respond to changes in the environment by altering morphotype and function during the progressive disease stage. Although substantial progress has been made in the drug development for MS, treatment of the progressive forms of the disease remains unsatisfactory. There is great interest in identifying novel agents for treating MS. Lentinus edodes is a traditional food, which can improve physiological function. Lentinan (LNT), a type of polysaccharide extracted from mushroom Lentinus edodes, is an anti-inflammatory and immunomodulatory agent. Here, we studied the remyelination effects of LNT and its therapeutic target in regulating the functions of neuroinflammation. We found that LNT enhanced remyelination and rescued motor deficiency by regulating dectin-1 receptor to inhibit neuroinflammation and microglial cell transformation. LNT promoted the conversion of microglial cells from the M1 status induced by LPS to the M2 status, enhanced the anti-inflammatory markers IL-10 and BDNF, inhibited inflammatory markers TNF-α and IL-1β, and downregulated the microglia activation and oligodendrocyte and astrocyte proliferation by modulating dectin-1. If we injected the dectin-1-specific inhibitor laminarin (Lam), the remyelination effects induced by LNT were completely abolished. Thus, these results suggest that LNT is a novel and potential therapeutic agent that can rescue MS neuroimmune imbalance and remyelination through a dectin-1 receptor-dependent mechanism.

Ganoderma lucidum Modulates Inflammatory Responses following 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP) Administration in Mice

Ganoderma lucidum, one of the most valued medicinal mushrooms, has been used for health supplements and medicine in China. Our previous studies have proved that Ganoderma lucidum extract (GLE) could inhibit activation of microglia and protect dopaminergic neurons in vitro. In the present study, we investigated the anti-neuroinflammatory potential of GLE in vivo on Parkinsonian-like pathological dysfunction. Male C57BL/6J mice were subjected to acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) lesion, and a treatment group was administered intragastrically with GLE at a dose of 400 mg/kg. Immunohistochemistry staining showed that GLE efficiently repressed MPTP-induced microglia activation in nigrostriatal region. Accordingly, Bio-plex multiple cytokine assay indicated that GLE treatment modulates abnormal cytokine expression levels. In microglia BV-2 cells incubated with LPS, increased expression of iNOS and NLRP3 were effectively inhibited by 800 μg/mL GLE. Furthermore, GLE treatment decreased the expression of LC3II/I, and further enhanced the expression of P62. These results indicated that the neuroprotection of GLE in an experimental model of PD was partially related to inhibition of microglia activation in vivo and vitro, possibly through downregulating the iNOS/NLRP3 pathway, inhibiting abnormal microglial autophagy and lysosomal degradation, which provides new evidence for Ganoderma lucidum in PD treatment.

Ganoderic acid A exerted antidepressant-like action through FXR modulated NLRP3 inflammasome and synaptic activity

Major depressive disorder (MDD) is a common, chronic, recurrent disease. The existing drugs are ineffective for approximately half of patients, so the development of antidepressant drugs with novel mechanisms is urgent. Cumulative evidence has shown neuro-inflammation plays a key role in the etiology of major depressive disorder. Clinical studies implicated that bile acids, an important component of gut-brain axis, inhibit neuro-inflammation and mediate the pathophysiology of the MDD. Here, we found that ganoderic acid A (GAA) modulated bile acid receptor FXR (farnesoid X receptor), inhibited brain inflammatory activity, and showed antidepressant effects in the chronic social defeat stress depression model, tail suspension, forced swimming, and sucrose preference tests. GAA directly inhibited the activity of the NLRP3 inflammasome, and activated the phosphorylation and expression of the AMPA receptor by modulating FXR in the prefrontal cortex of mice. If we knocked out FXR or injected the FXR-specific inhibitor z-gugglesterone (GS), the antidepressant effects induced by GAA were completely abolished. These results suggest that GAA modulates the bile acid receptor FXR and subsequently regulates neuroimmune and antidepressant behaviors. GAA and its receptor FXR have potential as targets for the treatment of MDD.

Ganoderic Acid A-Mediated Modulation of Microglial Polarization is Involved in Depressive-Like Behaviors and Neuroinflammation in a Rat Model of Post-Stroke Depression

BACKGROUND

Post-stroke depression (PSD) is a common complication after stroke. Ganoderic acid A (GAA), one of the main bioactive Ganoderma triterpenoids, exerts preventive and therapeutic effects in many diseases. However, the function of GAA in PSD has not been well studied.

METHODS

PSD model was established via stimulating rats with chronic unpredictable mild stress stimulations (CUMS) after middle cerebral artery occlusion (MCAO). Rats were treated with GAA before CUMS. Depressive-like behaviors were investigated by body weight alteration, open field test (OFT), and sucrose preference test (SPT). Neuronal damage was evaluated by hematoxylin and eosin (HE) staining and Western blotting. Inflammation was detected by enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Microglial polarization was analyzed via qRT-PCR and Western blotting. The extracellular signal-regulated kinase (ERK)/cAMP-response element-binding protein (CREB) pathway was analyzed by Western blotting, and inactivated by the inhibitor PD98059 (PD).

RESULTS

GAA attenuated PSD-induced depressive-like behaviors in rats. GAA mitigated PSD-induced neuronal damage and reduced BDNF and NGF levels in the cerebral hippocampus. GAA weakened PSD-induced inflammatory response in the cerebral hippocampus. GAA prevented pro-inflammatory (M1) polarization and promoted anti-inflammatory (M2) polarization, as indicated by decreased iNOS and CD86 levels and increased Arg-1 and CD206 levels. GAA restored the PSD-induced inactivation of the ERK/CREB pathway. GAA regulated M1/M2 microglial polarization by activating the ERK/CREB pathway.

CONCLUSION

GAA alleviated the depressive-like behaviors and brain inflammation in PSD rats, indicating its potential for PSD therapy.