Therapeutic activity of plant-derived alkaloid conophylline on metabolic syndrome and neurodegenerative disease models

Compositional analysis of baru (Dipteryx alata Vogel) pulp highlighting its industrial potential

Baru (Dipteryx alata Vogel), a fruit native to the Brazilian Cerrado, has gained scientific interest due to its nutritional potential and commercial value. Its edible seed, of high commercial value, represents around 5 % of the fruit. On the other hand, its pulp, a byproduct of the baru processing industry, is normally discarded, generating a huge volume of waste with reported antioxidant properties. This study investigates the composition and bioactive properties of baru pulp, aiming to identify the antioxidant components in this byproduct. Our analysis revealed that baru pulp is rich in sugars (41.86 %), fiber (29.12 %), and essential minerals, along with commercially valuable bioactive compounds such as trigonelline (139.10 mg 100 g-1), tannins (429.16 mg tannin equivalent 100 g-1), vitamin C (109.57 mg 100 g-1), and phenolic compounds such as trans-cinnamic acid (5.91 mg 100 g-1), chlorogenic acid, and gallic acid (1.07 mg 100 g-1). Industrially relevant sesquiterpenes, such as α-copaene and bicyclogermacrene, account for 42.75 % of the volatile profile, alongside germacrene D (11.69 %), aromadendrene (9.05 %), α-cubebene (6.84 %), β-elemene (5.90 %), and ledene (5.82 %), which are commonly used in essential oil production from other food matrices. While further studies are required to optimize extraction methods, these findings highlight baru pulp as a promising and low-cost alternative to traditional sources of bioactive compounds, with potential applications in functional food formulations and sustainable industrial processes. Specifically, the use of in natura pulp or its flour for food enrichment is recommended, supporting sustainability through the valorization of agro-industrial waste.

Advances in the pharmacological effects and mechanisms of Nelumbo nucifera gaertn. Extract nuciferine

ETHNOPHARMACOLOGIC RELEVANCE

The leaves of Nelumbo nucifera Gaertn. Are recorded in the earliest written documentation of traditional Chinese medicinal as "Ben Cao Gang Mu", a medicinal herb for blood clotting, dysentery and dizziness. Nuciferine, one of N. nucifera Gaertn. leaf extracts, has been shown to possess several pharmacological properties, including but not limited to ameliorating hyperlipidemia, stimulating insulin secretion, inducing vasodilation, reducing blood pressure, and demonstrating anti-arrhythmic properties.

AIM OF THE STUDY

In light of the latest research findings on nuciferine, this article provides a comprehensive overview of its chemical properties, pharmacological activities, and the underlying regulatory mechanisms. It aims to serve as a dependable reference for further investigations into the pharmacological effects and mechanisms of nuciferine.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the literature on extraction, separation, structural analysis and pharmacological activity of nuciferine published before November 2023. The key words are "extraction", "isolation", "purification" and "pharmacological action" and "nuciferine".

RESULTS

Nuciferine has been widely used in the treatment of ameliorating hyperlipidemia and lose weight, Nuciferine is a monomeric aporphine alkaloid extracted from the leaves of the plant Nymphaea caerulea and Nelumbo nucifera Gaertn. Nuciferine has pharmacological activities such as relaxing smooth muscles, improving hyperlipidemia, stimulating insulin secretion, vasodilation, inducing hypotension, antiarrhythmic effects, and antimicrobial and anti-HIV activities. These pharmacological properties lay a foundation for the treatment of tumors, inflammation, hyperglycemia, lipid-lowering and weight-loss, oxidative stress and other diseases with nuciferine.

CONCLUSION

Nuciferine has been clinically used to treat hyperlipidemia and aid in weight loss due to its effects on lipid levels, insulin secretion, vasodilation, blood pressure reduction, anti-tumor properties, and immune enhancement. However, other potential benefits of nuciferine have not yet been fully explored in clinical practice. Future research should delve deeper into its molecular structure, toxicity, side effects, and clinical pharmacology to uncover its full range of effects and pave the way for its safe and expanded clinical use.

Moringa oleifera Lam. as a potential plant for alleviation of the metabolic syndrome-A narrative review based on in vivo and clinical studies

The metabolic syndrome (MetS) refers to the co-occurrence of risk factors, including hyperglycaemia, increased body weight, hypertension and dyslipidemia, which eventually lead to diabetes and cardiovascular disease, a common health problem worldwide. Recently, there has been an increasing interest in the use of plant-based products for the management of MetS, because of their less detrimental and more beneficial effects. Moringa oleifera (Moringaceae), commonly known as drumstick, is cultivated worldwide for its nutritional and medicinal properties. This review focuses on the in vivo and human studies concerning the potential of M. oleifera in the alleviation of MetS and its comorbidities. The search for relevant articles was carried out in PubMed and Google Scholar databases. Randomised controlled and clinical trials from the PubMed database were included in this review. The results suggested that the administration of M. oleifera, in vivo, shows clear signs of improvement in MetS indices. Despite fewer human studies, the existing data documented convincing results that uphold the potential of M. oleifera against MetS. Therefore, future research discussing the probable mechanism of action is much needed which could further assure the usage of M. oleifera in the treatment regimen of MetS.

Molecular Mechanism Pathways of Natural Compounds for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, and its incidence continues to increase each year. Yet, there is still no definitive drug that can stop its development. This review focuses mainly on lipotoxicity, oxidative stress, inflammation, and intestinal flora dysbiosis to understand NAFLD's pathogenesis. In this review, we used NCBI's PubMed database for retrieval, integrating in vivo and in vitro experiments to reveal the therapeutic effects of natural compounds on NAFLD. We also reviewed the mechanisms by which the results of these experiments suggest that these compounds can protect the liver from damage by modulating inflammation, reducing oxidative stress, decreasing insulin resistance and lipid accumulation in the liver, and interacting with the intestinal microflora. The natural compounds discussed in these papers target a variety of pathways, such as the AMPK pathway and the TGF-β pathway, and have significant therapeutic effects. This review aims to provide new possible therapeutic lead compounds and references for the development of novel medications and the clinical treatment of NAFLD. It offers fresh perspectives on the development of natural compounds in preventing and treating NAFLD.

Dietary regulation of peroxisome proliferator-activated receptors in metabolic syndrome

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) are a class of ligand-activated nuclear transcription factors, members of the type nuclear receptor superfamily, with three subtypes, namely PPARα, PPARβ/δ, and PPARγ, which play a key role in the metabolic syndrome. In the past decades, a large number of studies have shown that natural products can act by regulating metabolic pathways mediated by PPARs.

PURPOSE

This work summarizes the physiological importance and clinical significance of PPARs and reviews the experimental evidence that natural products mediate metabolic syndrome via PPARs.

METHODS

This study reviews relevant literature on clinical trials, epidemiology, animals, and cell cultures published in NCBI PubMed, Scopus, Web of Science, Google Scholar, and other databases from 2001 to October 2022. Search keywords were "natural product" OR "botanical" OR "phytochemical" AND "PPAR" as well as free text words.

RESULTS

The modulatory involvement of PPARs in the metabolic syndrome has been supported by prior research. It has been observed that many natural products can treat metabolic syndrome by altering PPARs. The majority of currently described natural compounds are mild PPAR-selective agonists with therapeutic effects that are equivalent to synthetic medicines but less harmful adverse effects.

CONCLUSION

PPAR agonists can be combined with natural products to treat and prevent metabolic syndrome. Further human investigations are required because it is unknown how natural products cause harm and how they might have negative impacts.

Autophagic mechanisms in longevity intervention: role of natural active compounds

The term 'autophagy' literally translates to 'self-eating' and alterations to autophagy have been identified as one of the several molecular changes that occur with aging in a variety of species. Autophagy and aging, have a complicated and multifaceted relationship that has recently come to light thanks to breakthroughs in our understanding of the various substrates of autophagy on tissue homoeostasis. Several studies have been conducted to reveal the relationship between autophagy and age-related diseases. The present review looks at a few new aspects of autophagy and speculates on how they might be connected to both aging and the onset and progression of disease. Additionally, we go over the most recent preclinical data supporting the use of autophagy modulators as age-related illnesses including cancer, cardiovascular and neurodegenerative diseases, and metabolic dysfunction. It is crucial to discover important targets in the autophagy pathway in order to create innovative therapies that effectively target autophagy. Natural products have pharmacological properties that can be therapeutically advantageous for the treatment of several diseases and they also serve as valuable sources of inspiration for the development of possible new small-molecule drugs. Indeed, recent scientific studies have shown that several natural products including alkaloids, terpenoids, steroids, and phenolics, have the ability to alter a number of important autophagic signalling pathways and exert therapeutic effects, thus, a wide range of potential targets in various stages of autophagy have been discovered. In this review, we summarised the naturally occurring active compounds that may control the autophagic signalling pathways.

Potential of Compounds Originating from the Nature to Act in Hepatocellular Carcinoma Therapy by Targeting the Tumor Immunosuppressive Microenvironment: A Review

Hepatocellular carcinoma (HCC), the most prevalent subtype of liver cancer, is the second main reason for cancer-related deaths worldwide. In recent decades, sufficient evidence supported that immunotherapy was a safe and effective treatment option for HCC. However, tolerance and frequent recurrence and metastasis occurred in patients after immunotherapy due to the complicated crosstalk in the tumor immunosuppressive microenvironment (TIME) in HCC. Therefore, elucidating the TIME in HCC and finding novel modulators to target TIME for attenuating immune suppression is critical to optimize immunotherapy. Recently, studies have shown the potentially immunoregulatory activities of natural compounds, characterized by multiple targets and pathways and low toxicity. In this review, we concluded the unique role of TIME in HCC. Moreover, we summarized evidence that supports the hypothesis of natural compounds to target TIME to improve immunotherapy. Furthermore, we discussed the comprehensive mechanisms of these natural compounds in the immunotherapy of HCC. Accordingly, we present a well-grounded review of the naturally occurring compounds in cancer immunotherapy, expecting to shed new light on discovering novel anti-HCC immunomodulatory drugs from natural sources.

Botanical Interventions to Improve Glucose Control and Options for Diabetes Therapy

Diabetes mellitus is a major public health problem worldwide. This endocrine disease is clustered into distinct subtypes based on the route of development, with the most common forms associated with either autoimmunity (T1DM) or obesity (T2DM). A shared hallmark of both major forms of diabetes is a reduction in function (insulin secretion) or mass (cell number) of the pancreatic islet beta-cell. Diminutions in both mass and function are often present. A wide assortment of plants have been used historically to reduce the pathological features associated with diabetes. In this review, we provide an organized viewpoint focused around the phytochemicals and herbal extracts investigated using various preclinical and clinical study designs. In some cases, crude extracts were examined directly, and in others, purified compounds were explored for their possible therapeutic efficacy. A subset of these studies compared the botanical product with standard of care prescribed drugs. Finally, we note that botanical formulations are likely suspects for future drug discovery and refinement into class(es) of compounds that have either direct or adjuvant therapeutic benefit.

The PI3K/Akt signaling axis in Alzheimer's disease: a valuable target to stimulate or suppress?

Among the long list of age-related complications, Alzheimer's disease (AD) has the most dreadful impact on the quality of life due to its devastating effects on memory and cognitive abilities. Although a plausible correlation between the phosphatidylinositol 3-kinase (PI3K) signaling and different processes involved in neurodegeneration has been evidenced, few articles reviewed the task. The current review aims to unravel the mechanisms by which the PI3K pathway plays pro-survival roles in normal conditions, and also to discuss the original data obtained from international research laboratories on this topic. Responses to questions on how alterations of the PI3K/Akt signaling pathway affect Tau phosphorylation and the amyloid cascade are given. In addition, we provide a general overview of the association between oxidative stress, neuroinflammation, alterations of insulin signaling, and altered autophagy with aberrant activation of this axis in the AD brain. The last section provides a special focus on the therapeutic possibility of the PI3K/Akt/mTOR modulators, either categorized as chemicals or herbals, in AD. In conclusion, determining the correct timing for the administration of the drugs seems to be one of the most important factors in the success of these agents. Also, the role of the PI3K/Akt signaling axis in the progression or repression of AD widely depends on the context of the cells; generally speaking, while PI3K/Akt activation in neurons and neural stem cells is favorable, its activation in microglia cells may be harmful.

Natural Products in Therapeutic Management of Multineurodegenerative Disorders by Targeting Autophagy

Autophagy is an essential cellular process that involves the transport of cytoplasmic content in double-membraned vesicles to lysosomes for degradation. Neurons do not undergo cytokinesis, and thus, the cell division process cannot reduce levels of unnecessary proteins. The primary cause of neurodegenerative disorders (NDs) is the abnormal deposition of proteins inside neuronal cells, and this could be averted by autophagic degradation. Thus, autophagy is an important consideration when considering means of developing treatments for NDs. Various pharmacological studies have reported that the active components in herbal medicines exhibit therapeutic benefits in NDs, for example, by inhibiting cholinesterase activity and modulating amyloid beta levels, and α-synuclein metabolism. A variety of bioactive constituents from medicinal plants are viewed as promising autophagy controllers and are revealed to recover the NDs by targeting the autophagic pathway. In the present review, we discuss the role of autophagy in the therapeutic management of several NDs. The molecular process responsible for autophagy and its importance in various NDs and the beneficial effects of medicinal plants in NDs by targeting autophagy are also discussed.

Research progress of indole compounds with potential antidiabetic activity

New types of antidiabetic agents are continually needed with diabetes becoming the epidemic in the world. Indole alkaloids play an important role in natural products owing to their variable structures and versatile biological activities like anticonvulsant, anti-inflammatory, antidiabetic, antimicrobial, and anticancer activities, which are a promising source of novel antidiabetic drugs discovery. The synthesized indole derivatives possess similar properties to natural indole alkaloids. In the last two decades, more and more indole derivatives have been designed and synthesized for searching their bioactivities. This present review describes comprehensive structures of indole compounds with the potential antidiabetic activity including natural indole alkaloids and the synthetic indole derivatives based on the structure classification, summarizes their approaches isolated from natural sources or by synthetic methods, and discusses the antidiabetic effects and the mechanisms of action. Furthermore, this review also provides briefly synthetic procedures of some important indole derivatives.

Natural Compounds as Medical Strategies in the Prevention and Treatment of Psychiatric Disorders Seen in Neurological Diseases

Psychiatric disorders are frequently encountered in many neurological disorders, such as Alzheimer’s and Parkinson diseases along with epilepsy, migraine, essential tremors, and stroke. The most common comorbid diagnoses in neurological diseases are depression and anxiety disorders along with cognitive impairment. Whether the underlying reason is due to common neurochemical mechanisms or loss of previous functioning level, comorbidities are often overlooked. Various treatment options are available, such as pharmacological treatments, cognitive-behavioral therapy, somatic interventions, or electroconvulsive therapy. However oral antidepressant therapy may have some disadvantages, such as interaction with other medications, low tolerability due to side effects, and low efficiency. Natural compounds of plant origin are extensively researched to find a better and safer alternative treatment. Experimental studies have shown that phytochemicals such as alkaloids, terpenes, flavonoids, phenolic acids as well as lipids have significant potential in in vitro and in vivo models of psychiatric disorders. In this review, various efficacy of natural products in in vitro and in vivo studies on neuroprotective and their roles in psychiatric disorders are examined and their neuro-therapeutic potentials are shed light.

Adaptive Mechanisms of Tumor Therapy Resistance Driven by Tumor Microenvironment

Cancer is a disease which frequently has a poor prognosis. Although multiple therapeutic strategies have been developed for various cancers, including chemotherapy, radiotherapy, and immunotherapy, resistance to these treatments frequently impedes the clinical outcomes. Besides the active resistance driven by genetic and epigenetic alterations in tumor cells, the tumor microenvironment (TME) has also been reported to be a crucial regulator in tumorigenesis, progression, and resistance. Here, we propose that the adaptive mechanisms of tumor resistance are closely connected with the TME rather than depending on non-cell-autonomous changes in response to clinical treatment. Although the comprehensive understanding of adaptive mechanisms driven by the TME need further investigation to fully elucidate the mechanisms of tumor therapeutic resistance, many clinical treatments targeting the TME have been successful. In this review, we report on recent advances concerning the molecular events and important factors involved in the TME, particularly focusing on the contributions of the TME to adaptive resistance, and provide insights into potential therapeutic methods or translational medicine targeting the TME to overcome resistance to therapy in clinical treatment.

Pathogenesis of NASH and Promising Natural Products

Nonalcoholic steatohepatitis (NASH) is a common clinical condition that can lead to advanced liver diseases. The mechanism of the diaease progression, which is lacking effective therapy, remains obsure. Therefore, there is a need to understand the pathogenic mechanisms responsible for disease development and progression in order to develop innovative therapies. To accomplish this goal, experimental animal models that recapitulate the human disease are necessary. Currently, an increasing number of studies have focused on natural constituents from medicinal plants which have been emerged as a new hope for NASH. This review summarized the pathogenesis of NASH, animal models commonly used, and the promising targets for therapeutics. We also reviewed the natural constituents as potential NASH therapeutic agents.

NDUFA4L2 Regulated by HIF-1α Promotes Metastasis and Epithelial-Mesenchymal Transition of Osteosarcoma Cells Through Inhibiting ROS Production

Osteosarcoma (OS) accounts for a large proportion of the types of bone tumors that are newly diagnosed, and is a relatively common bone tumor. However, there are still no effective treatments for this affliction. One interesting avenue is related to the mitochondrial NDUFA4L2 protein, which is encoded by the nuclear gene and is known to be a critical mediator in the regulation of cell survival. Thus, in this study, we aimed to investigate the effect of NDUFA4L2 upon the metastasis and epithelial–mesenchymal transition of OS. We found that NDUFA4L2 protein expression was upregulated in hypoxic conditions. We also used 2-ME and DMOG, which are HIF-1α inhibitors and agonists, respectively, to assess the effects related to decreasing or increasing HIF-1α expression. 2-ME caused a significant decrease of NDUFA4L2 expression and DMOG had the opposite effect. It was obvious that down-regulation of NDUFA4L2 had a direct interaction with the apoptosis of OS cells. Western blotting, wound healing analyses, Transwell invasion assays, and colony formation assays all indicated and supported the conclusion that NDUFA4L2 promoted OS cell migration, invasion, proliferation, and the epithelial–mesenchymal transition. During experiments, we incidentally discovered that autophagy and the ROS inhibitor could be used to facilitate the rescuing of tumor cells whose NDUFA4L2 was knocked down. Our findings will help to further elucidate the dynamics underlying the mechanism of OS cells and have provided a novel therapeutic target for the treatment of OS.

Natural Compounds and Autophagy: Allies Against Neurodegeneration

Prolonging the healthy life span and limiting neurological illness are imperative goals in gerontology. Age-related neurodegeneration is progressive and leads to severe diseases affecting motility, memory, cognitive function, and social life. To date, no effective treatments are available for neurodegeneration and irreversible neuronal loss. Bioactive phytochemicals could represent a natural alternative to ensure active aging and slow onset of neurodegenerative diseases in elderly patients. Autophagy or macroautophagy is an evolutionarily conserved clearing process that is needed to remove aggregate-prone proteins and organelles in neurons and glia. It also is crucial in synaptic plasticity. Aberrant autophagy has a key role in aging and neurodegeneration. Recent evidence indicates that polyphenols like resveratrol and curcumin, flavonoids, like quercetin, polyamine, like spermidine and sugars, like trehalose, limit brain damage in vitro and in vivo. Their common mechanism of action leads to restoration of efficient autophagy by dismantling misfolded proteins and dysfunctional mitochondria. This review focuses on the role of dietary phytochemicals as modulators of autophagy to fight Alzheimer's and Parkinson's diseases, fronto-temporal dementia, amyotrophic lateral sclerosis, and psychiatric disorders. Currently, most studies have involved in vitro or preclinical animal models, and the therapeutic use of phytochemicals in patients remains limited.

Inhibition of matrix metalloproteinase expression and cellular invasion by NF-κB inhibitors of microbial origin

Matrix metalloproteinases (MMPs) are zinc-dependent extracellular matrix remodeling endopeptidases. MMPs cleave various matrix proteins such as collagen, elastin, gelatin and casein. MMPs are often implicated in pathological processes, such as cancer progression including metastasis. Meanwhile, microorganisms produce various secondary metabolites having unique structures. We designed and synthesized dehydroxymethylepoxyquinomicin (DHMEQ) based on the structure of epoxyquinomicin C derived from Amycolatopsis as an inhibitor of NF-κB. This compound inhibited cancer cell migration and invasion. Since DHMEQ is comparatively unstable in the body, we designed and synthesized a stable DHMEQ analog, SEMBL. SEMBL also inhibited cancer cell migration and invasion. We also looked for inhibitors of cancer cell migration and invasion from microbial culture filtrates. As a result, we isolated a known compound, ketomycin, from Actinomycetes. DHMEQ, SEMBL, and ketomycin are all NF-κB inhibitors, and inhibited the expression of MMPs in the inhibition of cellular migration and invasion. These are all compounds with comparatively low toxicity, and may be useful for the development of anti-metastasis agents.

Nuciferine Prevents Hepatic Steatosis by Regulating Lipid Metabolismin Diabetic Rat Model

Objective

This study investigatesthe nuciferine capacity to regulate the liver’s lipid metabolism regarding steatosis and injury in STZ-induced diabetic rats.

Materials and Methods

The rats were randomly divided into groups control, diabetic and nuciferine 200 mg/kg/ day treatment. After 4 days of STZ injection, the nuciferine group was treated and administered via oral gavages for 4 weeks. At the end of experiment, blood, liver, myocardial and muscular samples were collected.

Results

Nuciferine-treated significantly increased the body weight from 339.4g to 367.8g, but significantly decreased the food and water intake compared with diabetic rats. Also, the nuciferine-treated rats had significantly decreased TC, TG, and FFAs in the liver compared with the diabetic group, especially the serum markers of blood glucose. These were associated with the gene expression related to lipogenesis which was significantly down-regulated; the gene expression involved in lipolysis and fatty acid β-oxidation was significantly up-regulated. Discussion and

Conclusion

The data provide evidence that nuciferine supplementation could protect the liver by regulating lipid metabolism gene expression resulting in decreasing the steatosis and injury in diabetic rat. Thus, nuciferine could be developed as a diabetic adjuvant food additive in future.

Rapamycin- and starvation-induced autophagy are associated with miRNA dysregulation in A549 cells

MicroRNAs (miRNAs) are short (20-23 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. In recent years, deep sequencing of the transcription is being increasingly utilized with the promise of higher sensitivity for the identification of differential expression patterns as well as the opportunity to discover new transcripts, including new alternative isoforms and miRNAs. In this study, miRNAs from A549 cells treated with/without rapamycin or starvation were subject to genome-wide deep sequencing. A total of 1534 miRNAs were detected from the rapamycin- and starvation-treated A549 cells. Among them, 31 miRNAs were consistently upregulated and 131 miRNAs were downregulated in the treated cells when compared with the untreated cells. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis of the predicted target genes of the most significantly differentially expressed miRNAs revealed that the autophagy-related miRNAs are involved in cancer pathway. Taken together, our findings indicate that the underlying mechanism responsible for autophagy is associated with dysregulation of miRNAs in rapamycin- or starvation-induced A549 cells.

The beneficial roles of exercise training via autophagy in neurological diseases and possible mechanisms

Autophagy is a conservative catabolism process, participating in delivering the cytosol and cytosolic components to the lysosome. Abnormal autophagy is related to human pathologies, for instance diabetes, neurodegeneration, cardiovascular, macular degeneration, pulmonary, and cancer. Enormous evidences indicate that autophagy may mediate the cellular pathological condition in the process of neurological diseases. Exercise as a form of physiological stress may cause an adaptation, and autophagy is a necessary process for adaptational response to exercise. Autophagy during exercise may improve neurological function, control tissue maintain tissue integrity, and activate different signals pathway for adaptation. In this review, we summarize the possible mechanisms of exercise training via autophagy in neurological diseases.

Autophagy in Alzheimer's disease and promising modulatory effects of herbal medicine

Alzheimer's disease (AD) is a progressive and unremitting neurodegenerative disorder characterized by memory loss and cognitive impairment. It affects the quality of life of victims severely. The prevalence of AD has been increasing in recent years. Therefore, it is of great importance to elucidate the pathogenesis of AD and find out effective therapeutic approaches. Autophagy, a primary intracellular way of degrading aggregated proteins and damaged organelles, has been discovered to be involved in the pathological changes of AD. In the last few years, much progress has been made in finding autophagy regulators from natural products, providing new insights to develop treatment strategy for AD by targeting autophagy. In the present review, we provided an overview of the recent research progress regarding the function role of autophagy in AD, the regulation mechanisms of autophagy-lysosomal pathway as well as therapeutic potential of herbal medicine on AD by targeting autophagy.

Inhibition of Late and Early Phases of Cancer Metastasis by the NF-κB Inhibitor DHMEQ Derived from Microbial Bioactive Metabolite Epoxyquinomicin: A Review

We previously designed and synthesized dehydroxyepoxyquinomicin (DHMEQ) as an inhibitor of NF-κB based on the structure of microbial secondary metabolite epoxyquinomicin C. DHMEQ showed anti-inflammatory and anticancer activity in various in vivo disease models without toxicity. On the other hand, the process of cancer metastasis consists of cell detachment from the primary tumor, invasion, transportation by blood or lymphatic vessels, invasion, attachment, and formation of secondary tumor. Cell detachment from the primary tumor and subsequent invasion are considered to be early phases of metastasis, while tumor cell attachment to the tissue and secondary tumor formation the late phases. The assay system for the latter phase was set up with intra-portal-vein injection of pancreatic cancer cells. Intraperitoneal administration of DHMEQ was found to inhibit liver metastasis possibly by decreasing the expression of MMP-9 and IL-8. Also, when the pancreatic cancer cells treated with DHMEQ were inoculated into the peritoneal cavity of mice, the metastatic foci formation was inhibited. These results indicate that DHMEQ is likely to inhibit the late phase of metastasis. Meanwhile, we have recently employed three-dimensional (3D) culture of breast cancer cells for the model of early phase metastasis, since the 3D invasion just includes cell detachment and invasion into the matrix. DHMEQ inhibited the 3D invasion of breast cancer cells at 3D-nontoxic concentrations. In this way, DHMEQ was shown to inhibit the late and early phases of metastasis. Thus, DHMEQ is likely to be useful for the suppression of cancer metastasis.