Neuroprotective Effects of Extracts from Tiger Milk Mushroom Lignosus rhinocerus Against Glutamate-Induced Toxicity in HT22 Hippocampal Neuronal Cells and Neurodegenerative Diseases in Caenorhabditis elegans

Tiger Milk Mushroom: A Comprehensive Review of Nutritional Composition, Phytochemicals, Health Benefits, and Scientific Advancements with Emphasis on Chemometrics and Multi-Omics

This article presents a comprehensive overview of tiger milk mushroom (TMM), covering its nutritional composition, phytochemicals, health benefits, and related scientific advancements. It describes various potential positive health benefits of TMM, including anticancer, anti-inflammatory, respiratory function enhancement, antioxidant, anti-aging, neuroprotective, photoprotective, antidiabetic, wound-healing, and anti-HIV, among others. This article also underlines the importance of further research into the phytochemicals present in TMM for additional discoveries. It underscores the importance of further research into phytochemicals content of TMM for additional discoveries and emphasizes the potential applications of TMM in nutrition, health, and well-being. Sophisticated techniques, such as chemometrics and multi-omics technologies revealed latest scientific advancements of TMM. This comprehensive overview provides a foundation for future research and development in harnessing TMM's potential for human health.

Experimental Models in Unraveling the Biological Mechanisms of Mushroom-Derived Bioactives against Aging- and Lifestyle-Related Diseases: A Review

Mushrooms have garnered considerable interest among researchers due to their immense nutritional and therapeutic properties. The presence of biologically active primary and secondary metabolites, which includes several micronutrients, including vitamins, essential minerals, and other dietary fibers, makes them an excellent functional food. Moreover, the dietary inclusion of mushrooms has been reported to reduce the incidence of aging- and lifestyle-related diseases, such as cancer, obesity, and stroke, as well as to provide overall health benefits by promoting immunomodulation, antioxidant activity, and enhancement of gut microbial flora. The multifunctional activities of several mushroom extracts have been evaluated by both in vitro and in vivo studies using cell lines along with invertebrate and vertebrate model systems to address human diseases and disorders at functional and molecular levels. Although each model has its own strengths as well as lacunas, various studies have generated a plethora of data regarding the regulating players that are modulated in order to provide various protective activities; hence, this review intends to compile and provide an overview of the plausible mechanism of action of mushroom-derived bioactives, which will be helpful in future medicinal explorations.

In vivo anti-tumor activity of Lignosus rhinocerus TM02® using a MCF7-xenograft NCr nude mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Lignosus rhinocerus (Cooke) Ryvarden (also known as Tiger Milk mushroom, TMM), is a basidiomycete belonging to the Polyporaceae family. It has been documented to be used by traditional Chinese physicians and indigenous people in Southeast Asia to treat a variety of illnesses, such as gastritis, arthritis, and respiratory conditions, as well as to restore patients' physical well-being. TMM has also been used in folk medicine to treat cancer. For example, people from the indigenous Kensiu tribe of northeast Kedah (Malaysia) apply shredded TMM sclerotium mixed with water directly onto breast skin to treat breast cancer, while Chinese practitioners from Hong Kong, China prescribe TMM sclerotium as a treatment for liver cancer. L. rhinocerus has previously been demonstrated to possess selective anti-proliferative properties in vitro, however pre-clinical in vivo research has not yet been conducted.

AIM OF STUDY

This study aimed to examine the anti-tumor activities of L. rhinocerus TM02®, using two different sample preparations [cold water extract (CWE) and fraction] via various routes of administration (oral and intraperitoneal) on an MCF7-xenograft nude mouse model. This study also investigated the inhibitory effect of TM02® CWE and its fractions against COX-2 in vitro using LPS-induced RAW264.7 macrophages, on the basis of the relationship between COX-2 and metastasis, apoptosis resistance, as well as the proliferation of cancer cells.

MATERIALS AND METHODS

The first preparation, L. rhinocerus TM02® sclerotium powder (TSP) was dissolved in cold water to obtain the cold water extract (CWE). It was further fractionated based on its molecular weight to obtain the high (HMW), medium (MMW) and low (LMW) molecular weight fractions. The second preparation, known as the TM02® rhinoprolycan fraction (TRF), was obtained by combining the HMW and MMW fractions. TSP was given orally to mimic the daily consumption of a supplement; TRF was administered intraperitoneally to mimic typical tumorous cancer treatment with a rapid and more thorough absorption through the peritoneal cavity. Another experiment was conducted to examine changes in COX-2 activity in LPS-induced RAW264.7 macrophages after a 1-h pre-treatment with CWE, HMW, and MMW.

RESULTS

Our results revealed that intraperitoneal TRF-injection (90 μg/g BW) for 20 days reduced initial tumor volume by ∼64.3% (n = 5). The percentage of apoptotic cells was marginally higher in TRF-treated mice vs. control, suggesting that induction of apoptosis as one of the factors that led to tumor shrinkage. TSP (500 μg/g BW) oral treatment (n = 5) for 63 days (inclusive of pre-treatment prior to tumor inoculation) effectively inhibited tumor growth. Four of the five tumors totally regressed, demonstrating the effectiveness of TSP ingestion in suppressing tumor growth. Although no significant changes were found in mouse serum cytokines (TNF-α, IL-5, IL-6 and CCL2), some increasing and decreasing trends were observed. This may suggest the immunomodulatory potential of these treatments that can directly or indirectly affect tumor growth. Pre-treatment with CWE, HMW and MMW significantly reduced COX-2 activity in RAW264.7 macrophages upon 24 h LPS-stimulation, suggesting the potential of L. rhinocerus TM02® extract and fractions in regulating M1/M2 polarization.

CONCLUSION

Based on the findings of our investigation, both the rhinoprolycan fraction and crude sclerotial powder from L. rhinocerus TM02® demonstrated tumor suppressive effects, indicating that they contain substances with strong anticancer potential. The antitumor effects of L. rhinocerus TM02® in our study highlights the potential for further explorations into its mechanism of action and future development as a prophylactic or adjunct therapeutic against tumorous cancer.

Tactics with Prebiotics for the Treatment of Metabolic Dysfunction-Associated Fatty Liver Disease via the Improvement of Mitophagy

Mitophagy/autophagy plays a protective role in various forms of liver damage, by renovating cellular metabolism linking to sustain liver homeostasis. A characterized pathway for mitophagy is the phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1)/Parkin-dependent signaling pathway. In particular, PINK1-mediated mitophagy could play an indispensable role in improving the metabolic dysfunction-associated fatty liver disease (MAFLD) which could precede to steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma. In addition, the PI3K/AKT/mTOR pathway might regulate the various characteristics of cellular homeostasis including energy metabolism, cell proliferation, and/or cell protection. Therefore, targeting mitophagy with the alteration of PI3K/AKT/mTOR or PINK1/Parkin-dependent signaling to eliminate impaired mitochondria might be an attractive strategy for the treatment of MAFLD. In particular, the efficacy of prebiotics for the treatment of MAFLD has been suggested to be useful via the modulation of the PI3K/AKT/mTOR/AMPK pathway. Additionally, several edible phytochemicals could activate mitophagy for the improvement of mitochondrial damages, which could also be a promising option to treat MAFLD with providing liver protection. Here, the potential therapeutics with several phytochemicals has been discussed for the treatment of MAFLD. Tactics with a viewpoint of prospective probiotics might contribute to the development of therapeutic interventions.

Beyond the classical amyloid hypothesis in Alzheimer's disease: Molecular insights into current concepts of pathogenesis, therapeutic targets, and study models

Alzheimer's disease (AD) is one of the progressive neurodegenerative disorders and the most common cause of dementia in the elderly worldwide causing difficulties in the daily life of the patient. AD is characterized by the aberrant accumulation of β-amyloid plaques and tau protein-containing neurofibrillary tangles (NFTs) in the brain giving rise to neuroinflammation, oxidative stress, synaptic failure, and eventual neuronal cell death. The total cost of care in AD treatment and related health care activities is enormous and pharmaceutical drugs approved by Food and Drug Administration have not manifested sufficient efficacy in protection and therapy. In recent years, there are growing studies that contribute a fundamental understanding to AD pathogenesis, AD-associated risk factors, and pharmacological intervention. However, greater molecular process-oriented research in company with suitable experimental models is still of the essence to enhance the prospects for AD therapy and cell lines as a disease model are still the major part of this milestone. In this review, we provide an insight into molecular mechanisms, particularly the recent concept in gut-brain axis, vascular dysfunction and autophagy, and current models used in the study of AD. Here, we emphasized the importance of therapeutic strategy targeting multiple mechanisms together with utilizing appropriate models for the discovery of novel effective AD therapy. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.

Potential Diets to Improve Mitochondrial Activity in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease, the pathogenesis of which is based on alternations in the mitochondria of motor neurons, causing their progressive death. A growing body of evidence shows that more efficient mitophagy could prevent and/or treat this disorder by suppressing mitochondrial dysfunction-induced oxidative stress and inflammation. Mitophagy has been considered one of the main mechanisms responsible for mitochondrial quality control. Since ALS is characterized by enormous oxidative stress, several edible phytochemicals that can activate mitophagy to remove damaged mitochondria could be considered a promising option to treat ALS by providing neuroprotection. Therefore, it is of great significance to explore the mechanisms of mitophagy in ALS and to understand the effects and/or molecular mechanisms of phytochemical action, which could translate into a treatment for neurodegenerative diseases, including ALS.

Natural Bioactive Products and Alzheimer’s Disease Pathology: Lessons from Caenorhabditis elegans Transgenic Models

Alzheimer’s disease (AD) is an age-dependent, progressive disorder affecting millions of people. Currently, the therapeutics for AD only treat the symptoms. Although they have been used to discover new products of interest for this disease, mammalian models used to investigate the molecular determinants of this disease are often prohibitively expensive, time-consuming and very complex. On the other hand, cell cultures lack the organism complexity involved in AD. Given the highly conserved neurological pathways between mammals and invertebrates, Caenorhabditis elegans has emerged as a powerful tool for the investigation of the pathophysiology of human AD. Numerous models of both Tau- and Aβ-induced toxicity, the two prime components observed to correlate with AD pathology and the ease of performing RNA interference for any gene in the C. elegans genome, allow for the identification of multiple therapeutic targets. The effects of many natural products in main AD hallmarks using these models suggest promising health-promoting effects. However, the way in which they exert such effects is not entirely clear. One of the reasons is that various possible therapeutic targets have not been evaluated in many studies. The present review aims to explore shared therapeutical targets and the potential of each of them for AD treatment or prevention.

Protective Effect of NGR1 against Glutamate-Induced Cytotoxicity in HT22 Hippocampal Neuronal Cells by Upregulating the SIRT1/Wnt/β-Catenin Pathway

Notoginsenoside R1 (NGR1) is an active compound isolated from Panax notoginseng. Despite the NGR1 having been used as a traditional medicine, little is known about the neuroprotective effects. In this study, we investigate the protective effects of NGR1 against glutamate-induced cytotoxicity in HT22 cells and its possible molecular mechanism. We assessed the toxicity of NGR1 and the protective activity by MTT assay. The levels of oxidative stress indices superoxide dismutase (SOD), glutathione (GSH), and mitochondrial membrane potential (MMP) were measured by the kits. The levels of reactive oxygen species (ROS) and Ca²⁺ concentration were measured by flow cytometry. Furthermore, we determined the expression of mitochondrial dysfunction related protein PINK1, Parkin, silent mating type information regulation 2 homolog-1 (sirtuin 1; SIRT1), and Wnt/β-catenin by Western blotting. Here, we discovered that glutamate treatment led to cell viability loss, apoptosis facilitation, Ca²⁺ upregulation, MMP fluorescence intensity downregulation, and ROS generation of HT22 cells. In parallel, expression of Parkin was declined by glutamate. While, NGR1 treatment alleviated all the above phenomena. We further clarified that NGR1 alleviated glutamate-induced oxidative stress, apoptosis, and mitochondrial dysfunction by upregulating SIRT1 to activate Wnt/β-catenin pathways. These findings demonstrate that NGR1 alleviated glutamate-induced cell damage, and NGR1 may play a protective role in neurological complications.

Neuroprotective Effects against Glutamate-Induced HT-22 Hippocampal Cell Damage and Caenorhabditis elegans Lifespan/Healthspan Enhancing Activity of Auricularia polytricha Mushroom Extracts

Oxidative stress is associated with several diseases, particularly neurodegenerative diseases, commonly found in the elderly. The attenuation of oxidative status is one of the alternatives for neuroprotection and anti-aging. Auricularia polytricha (AP), an edible mushroom, contains many therapeutic properties, including antioxidant properties. Herein, we report the effects of AP extracts on antioxidant, neuroprotective, and anti-aging activities. The neuroprotective effect of AP extracts against glutamate-induced HT-22 neuronal damage was determined by evaluating the cytotoxicity, intracellular reactive oxygen species (ROS) accumulation, and expression of antioxidant enzyme genes. Lifespan and healthspan assays were performed to examine the effects of AP extracts from Caenorhabditis elegans. We found that ethanolic extract (APE) attenuated glutamate-induced HT-22 cytotoxicity and increased the expression of antioxidant enzyme genes. Moreover, APE promoted in the longevity and health of the C. elegans. Chemical analysis of the extracts revealed that APE contains the highest quantity of flavonoids and a reasonable percentage of phenols. The lipophilic compounds in APE were identified by gas chromatography/mass spectrometry (GC/MS), revealing that APE mainly contains linoleic acid. Interestingly, linoleic acid suppressed neuronal toxicity and ROS accumulation from glutamate induction. These results indicate that AP could be an exciting natural source that may potentially serves as neuroprotective and anti-aging agents.

Bioactive components of mushrooms: Processing effects and health benefits

Mushrooms have been recognized for their culinary attributes for long and were relished in the most influential civilizations in history. Currently, they are the focus of renewed research because of their therapeutic abilities. Nutritional benefits from mushrooms are in the form of a significant source of essential proteins, dietary non-digestible carbohydrates, unsaturated fats, minerals, as well as various vitamins, which have enhanced its consumption, and also resulted in the development of various processed mushroom products. Mushrooms are also a crucial ingredient in traditional medicine for their healing potential and curative properties. The literature on the nutritional, nutraceutical, and therapeutic potential of mushrooms, and their use as functional foods for the maintenance of health was reviewed, and the available literature indicates the enormous potential of the bioactive compounds present in mushrooms. Future research should be focused on the development of processes to retain the mushroom bioactive components, and valorization of waste generated during processing. Further, the mechanisms of action of mushroom bioactive components should be studied in detail to delineate their diverse roles and functions in the prevention and treatment of several diseases.

Extracts of the Tiger Milk Mushroom (Lignosus rhinocerus) Enhance Stress Resistance and Extend Lifespan in Caenorhabditis elegans via the DAF-16/FoxO Signaling Pathway

The tiger milk mushroom, Lignosus rhinocerus (LR), exhibits antioxidant properties, as shown in a few in vitro experiments. The aim of this research was to study whether three LR extracts exhibit antioxidant activities in Caenorhabditis elegans. In wild-type N2 nematodes, we determined the survival rate under oxidative stress caused by increased intracellular ROS concentrations. Transgenic strains, including TJ356, TJ375, CF1553, CL2166, and LD1, were used to detect the expression of DAF-16, HSP-16.2, SOD-3, GST-4, and SKN-1, respectively. Lifespan, lipofuscin, and pharyngeal pumping rates were assessed. Three LR extracts (ethanol, and cold and hot water) protected the worms from oxidative stress and decreased intracellular ROS. The extracts exhibited antioxidant properties through the DAF-16/FOXO pathway, leading to SOD-3 and HSP-16.2 modification. However, the expression of SKN-1 and GST-4 was not changed. All the extracts extended the lifespan. They also reduced lipofuscin (a marker for aging) and influenced the pharyngeal pumping rate (another marker for aging). The extracts did not cause dietary restriction. This novel study provides evidence of the functional antioxidant and anti-aging properties of LR. Further studies must confirm that they are suitable for use as antioxidant supplements.