Myricanol mitigates lipid accumulation in 3T3-L1 adipocytes and high fat diet-fed zebrafish via activating AMP-activated protein kinase

Natural hypoglycaemic bioactives: Newer avenues and newer possibilities

The incidences of endocrine and metabolic disorders like diabetes have increased worldwide. Several proposed molecular pathways mechanisms for the management of diabetes have been identified, but glycaemic control is still a challenging task in the drug discovery process. Most of the drug discovery processes lead to numerous scaffolds that are prominent in natural products. The review deals with the natural bioactives as an α-amylase inhibitors, α-glucosidase inhibitors, protein tyrosine phosphatase-1B inhibitors, dipeptidyl peptidase-IV inhibitors, G-protein coupled receptors-40 agonists, PPAR-γ agonists and the activators of 5'-adenosine monophosphate-activated protein kinase and glucokinase. So, in this review, we focused on the hypoglycaemic bioactives, which will assist scientific developers, traditional medicinal practitioners, and readers to discover some potent antidiabetic molecules. Strategies like chemometric approaches, scaffold hopping, and total synthesis of natural products by group modification or ring opening/closing mechanism could be useful for the development of novel hit/lead antidiabetic molecules. The study concludes that each phyto molecule inherits a potential to get explored by repurposing techniques for various antidiabetic targets and offer an alternative antidiabetic therapeutic medicinal potential.

Roles of natural products on myokine expression and secretion in skeletal muscle atrophy

Skeletal muscles serve both in movement and as endocrine organs. Myokines secreted by skeletal muscles activate biological functions within muscles and throughout the body via autocrine, paracrine, and/or endocrine pathways. Skeletal muscle atrophy can influence myokine expression and secretion, while myokines can impact the structure and function of skeletal muscles. Regulating the expression and secretion of myokines through the pharmacological approach is a strategy for alleviating skeletal muscle atrophy. Natural products possess complex structures and chemical properties. Previous studies have demonstrated that various natural products exert beneficial effects on skeletal muscle atrophy. This article reviewed the regulatory effects of natural products on myokines and summarized the research progress on skeletal muscle atrophy associated with myokine regulation. The focus is on how small-molecule natural products affect the regulation of interleukin 6 (IL-6), irisin, myostatin, IGF-1, and FGF-21 expression. We contend that the development of small-molecule natural products targeting the regulation of myokines holds promise in combating skeletal muscle atrophy.

Post Natal Microbial and Metabolite Transmission: The Path from Mother to Infant

The entero-mammary pathway is a specialized route that selectively translocates bacteria to the newborn's gut, playing a crucial role in neonatal development. Previous studies report shared bacterial and archaeal taxa between human milk and neonatal intestine. However, the functional implications for neonatal development are not fully understood due to limited evidence. This study aimed to identify and characterize the microbiota and metabolome of human milk, mother, and infant stool samples using high-throughput DNA sequencing and FT-ICR MS methodology at delivery and 4 months post-partum. Twenty-one mothers and twenty-five infants were included in this study. Our results on bacterial composition suggest vertical transmission of bacteria through breastfeeding, with major changes occurring during the first 4 months of life. Metabolite chemical characterization sheds light on the growing complexity of the metabolites. Further data integration and network analysis disclosed the interactions between different bacteria and metabolites in the biological system as well as possible unknown pathways. Our findings suggest a shared bacteriome in breastfed mother-neonate pairs, influenced by maternal lifestyle and delivery conditions, serving as probiotic agents in infants for their healthy development. Also, the presence of food biomarkers in infants suggests their origin from breast milk, implying selective vertical transmission of these features.

Myricanol attenuates sepsis-induced inflammatory responses by nuclear factor erythroid 2-related factor 2 signaling and nuclear factor kappa B/mitogen-activated protein kinase pathway via upregulating Sirtuin 1

Sepsis, a life-threatening condition characterized by dysregulated immune responses, remains a significant clinical challenge. Myricanol, a natural compound, plays a variety of roles in regulating lipid metabolism, anti-cancer, anti-neurodegeneration, and it could act as an Sirtuin 1 (SIRT1) activator. This study aimed to explore the therapeutic potential and underlying mechanism of myricanol in the lipopolysaccharide (LPS)-induced sepsis model. In vivo studies revealed that myricanol administration significantly improved the survival rate of LPS-treated mice, effectively mitigating LPS-induced inflammatory responses in lung tissue. Furthermore, in vitro studies demonstrated that myricanol treatment inhibited the expression of pro-inflammatory cytokines, attenuated signal pathway activation, and reduced oxidative stress in macrophages. In addition, we demonstrated that myricanol selectively enhances SIRT1 activation in LPS-stimulated macrophages, and all of the protective effect of myricanol were reversed through SIRT1 silencing. Remarkably, the beneficial effects of myricanol against LPS-induced sepsis were abolished in SIRT1 myeloid-specific knockout mice, underpinning the critical role of SIRT1 in mediating myricanol's therapeutic efficacy. In summary, this study provides significant evidence that myricanol acts as a potent SIRT1 activator, targeting inflammatory signal pathways and oxidative stress to suppress excessive inflammatory responses. Our findings highlight the potential of myricanol as a novel therapeutic agent for the treatment of LPS-induced sepsis.

Myricanol prevents aging-related sarcopenia by rescuing mitochondrial dysfunction via targeting peroxiredoxin 5

Aging is a process that represents the accumulation of changes in organism overtime. In biological level, accumulations of molecular and cellular damage in aging lead to an increasing risk of diseases like sarcopenia. Sarcopenia reduces mobility, leads to fall-related injuries, and diminishes life quality. Thus, it is meaningful to find out novel therapeutic strategies for sarcopenia intervention that may help the elderly maintain their functional ability. Oxidative damage-induced dysfunctional mitochondria are considered as a culprit of muscle wasting during aging. Herein, we aimed to demonstrate whether myricanol (MY) protects aged mice against muscle wasting through alleviating oxidative damage in mitochondria and identify the direct protein target and its underlying mechanism. We discovered that MY protects aged mice against the loss of muscle mass and strength through scavenging reactive oxygen species accumulation to rebuild the redox homeostasis. Taking advantage of biophysical assays, peroxiredoxin 5 was discovered and validated as the direct target of MY. Through activating peroxiredoxin 5, MY reduced reactive oxygen species accumulation and damaged mitochondrial DNA in C2C12 myotubes. Our findings provide an insight for therapy against sarcopenia through alleviating oxidative damage-induced dysfunctional mitochondria by targeting peroxiredoxin 5, which may contribute an insight for healthy aging.

Myricanol improves metabolic profiles in dexamethasone induced lipid and protein metabolism disorders in mice

Myricanol (MY) is one of the main active components from bark of Myrica Rubra. It is demonstrated that MY rescues dexamethasone (DEX)-induced muscle dysfunction via activating silent information regulator 1 (SIRT1) and increasing adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation. Since SIRT1 and AMPK are widely involved in the metabolism of nutrients, we speculated that MY may exert beneficial effects on DEX-induced metabolic disorders. This study for the first time applied widely targeted metabolomics to investigate the beneficial effects of MY on glucose, lipids, and protein metabolism in DEX-induced metabolic abnormality in mice. The results showed that MY significantly reversed DEX-induced soleus and gastrocnemius muscle weight loss, muscle fiber damage, and muscle strength loss. MY alleviated DEX-induced metabolic disorders by increasing SIRT1 and glucose transporter type 4 (GLUT4) expressions. Additionally, myricanol prevented muscle cell apoptosis and atrophy by inhibiting caspase 3 cleavages and muscle ring-finger protein-1 (MuRF1) expression. Metabolomics showed that MY treatment reversed the serum content of carnitine ph-C1, palmitoleic acid, PS (16:0_17:0), PC (14:0_20:5), PE (P-18:1_16:1), Cer (t18:2/38:1(2OH)), four amino acids and their metabolites, and 16 glycerolipids in DEX mice. Kyoto encyclopedia of genes and genomes (KEGG) and metabolic set enrichment analysis (MSEA) analysis revealed that MY mainly affected metabolic pathways, glycerolipid metabolism, lipolysis, fat digestion and absorption, lipid and atherosclerosis, and cholesterol metabolism pathways through regulation of metabolites involved in glutathione, butanoate, vitamin B6, glycine, serine and threonine, arachidonic acid, and riboflavin metabolism. Collectively, MY can be used as an attractive therapeutic agent for DEX-induced metabolic abnormalities.

Metabolomics Reveals Antioxidant Metabolites in Colored Rice Grains

Colored rice is richer in nutrients and contains more nutrients and bioactive substances than ordinary white rice. Moderate consumption of black (purple) rice has a variety of physiological effects, such as antioxidant effects, blood lipid regulation, and blood sugar control. Therefore, we utilized nontargeted metabolomics, quantitative assays for flavonoid and phenolic compounds, and physiological and biochemical data to explore the correlations between metabolites and the development of antioxidant characteristics in pigmented rice seeds. The findings indicated that, among Yangjinnuo 818 (YJN818), Hongnuo (HN), Yangchannuo 1 hao (YCN1H), and Yangzi 6 hao (YZ6H), YZ6H exhibited the highest PAL activity, which was 2.13, 3.08, and 3.25 times greater than those of YJN818, HN, and YCN1H, respectively. YZ6H likewise exhibited the highest flavonoid content, which was 3.8, 7.06, and 35.54 times greater than those of YJN818, HN, and YCN1H, respectively. YZ6H also had the highest total antioxidant capacity, which was 2.42, 3.76, and 3.77 times greater than those of YJN818, HN, and YCN1H, respectively. Thus, purple rice grains have stronger antioxidant properties than other colored rice grains. Receiver operating characteristic (ROC) curve analysis revealed that trans-3,3',4',5,5',7-hexahydroxyflavanone, phorizin, and trilobatin in the YZ6H, HN, and YCN1H comparison groups all had area under the curve (AUC) values of 1. Phlorizin, trans-3,3',4',5,5',7-hexahydroxyflavanone, and trilobatin were recognized as indices of antioxidant capability in colored rice in this research. This research adds to the understanding of antioxidant compounds in pigmented rice, which can increase the nutritional value of rice and promote the overall well-being of individuals. This type of information is of immense importance in maintaining a balanced and healthy diet.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

Evaluation of the Chemical Stability, Membrane Permeability and Antiproliferative Activity of Cyclic Diarylheptanoids from European Hornbeam (Carpinus betulus L.)

Four cyclic diarylheptanoids-carpinontriols A (1) and B (2), giffonin X (3) and 3,12,17-trihydroxytricyclo [12.3.1.12,6]nonadeca-1(18),2(19),3,5,14,16-hexaene-8,11-dione (4)-were isolated from Carpinus betulus (Betulaceae). Chemical stability of the isolated diarylheptanoids was evaluated as a function of storage temperature (-15, 5, 22 °C) and time (12 and 23 weeks). The effect of the solvent and the pH (1.2, 6.8, 7.4) on the stability of these diarylheptanoids was also investigated. Compounds 2 and 4 showed good stability both in aqueous and methanolic solutions at all investigated temperatures. Only 2 was stable at all three studied biorelevant pH values. Degradation products of 1 and 3 were formed by the elimination of a water molecule from the parent compounds, as confirmed by ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HR-MS). The permeability of the compounds across biological membranes was evaluated by the parallel artificial membrane permeability assay (PAMPA). Compound 3 possesses a logPe value of -5.92 ± 0.04 in the blood-brain barrier-specific PAMPA-BBB study, indicating that it may be able to cross the blood-brain barrier via passive diffusion. The in vitro antiproliferative activity of the compounds was investigated against five human cancer cell lines, confirming that 1 inhibits cell proliferation in A2058 human metastatic melanoma cells.

NMR-tracking for 15,16-seco-cycloartane triterpenes from Cimicifuga acerina

Twelve undescribed 15,16-seco-cycloartane triterpenoids, 15,16-seco-cimiterpenes C-N, as well as five previously reported analogs were isolated by NMR-tracking methods from the rhizomes of Cimicifuga acerina (Sieb. et Zucc.) Tanaka. Among them, 15,16-seco-cimiterpenes C-N were the first 15,16-seco-cycloartane triterpenoids featuring acetal or hemiacetal structures at C-15. The chemical structures of 15,16-seco-cimiterpenes C-N were determined based on comprehensive spectroscopic analysis, chemical method, and comparison with the previous literature data. After that, all these compounds were evaluated for their lipid-lowering effects on 3T3-L1 adipocytes.15,16-seco-cimiterpene D was found to exhibit a comparable reducing lipid effect at the concentration of 50 μM, with an inhibition rate at 35.96%.

Myrica esculenta Buch.-Ham. (ex D. Don): A Review on its Phytochemistry, Pharmacology and Nutritional Potential

Myrica esculenta is an important ethnomedicinal plant used in the traditional system of medicine and as an important nutraceutical. Several studies on the plant justify its use in alternative systems of medicine and establish a scientific rationale for its possible therapeutic application. The plant contains a range of biologically active classes of compounds, particularly diarylheptanoids, flavonoids, terpenes, tannins, and glycosides. The nutraceutical potential of the plant can be particularly attributed to its fruit, and several studies have demonstrated the presence of carbohydrates, proteins, fats, fiber content, and minerals like sodium, potassium, calcium, manganese, iron, copper, and zinc, in it. The current review aims to provide complete insight into the phytochemistry, pharmacological potential, and nutritional potential of the plant, which would not only serve as a comprehensive source of information but also will highlight the scope of isolation and evaluation of these molecules for various disease conditions.

Methanolic fruit extract of Myrica nagi protects the hypothalamus and attenuates inflammation associated with gold thioglucose- and high-fat diet-induced obesity via various adipokines

BACKGROUND

Myrica nagi is popular in unani and ayurveda. Chemical constituents like myricetin isolated from its fruit has been shown to exert beneficial effects against cardiovascular disease, cancer, inflammatory conditions, and metabolic disorders.

OBJECTIVES

This study aimed to elucidate the anti-obesity effect of the methanolic extract of M. nagi (MEMN) using in vivo animal models of obesity induced by gold thioglucose or a high-fat diet.

MATERIALS AND METHODS

The obese mice were treated or untreated with MEMN for 8 weeks. Thereafter, feed intake, Lee index, and body mass index (BMI); biochemical parameters such as lipid profile, liver enzymes and specific biomarkers of obesity, including insulin, leptin, adiponectin, free fatty acids (FFA), monocyte chemoattractant protein (MCP)-1, and resistin, were recorded. The weight and histopathology of organs and fat tissue were examined to validate the effectiveness of the extract.

RESULTS

MEMN administration at various doses significantly reduced the induced weight gain, feed intake, BMI, and Lee index. Adipose tissue decreased as the MEMN dose increased. MEMN attenuated liver enzyme activity, decreased lipid, leptin, MCP-1, resistin, and FFA levels, and increased adiponectin levels. It also increased protection of liver cells and decreased accumulation of mesenteric fat.

CONCLUSIONS

MEMN supplementation decreased weight and improved obesity serum/plasma lipid biomarker, insulin, leptin, adiponectin, MCP-1, and resistin levels. The weight-reducing activity of MEMN may be mediated by decreased gastrointestinal fat absorption and modulation of inflammation associated signaling pathways, leading to reduced adipose inflammation associated with energy expenditure.

An overview of the nutritional value, health properties, and future challenges of Chinese bayberry

Chinese bayberry (CB) is among the most popular and valuable fruits in China owing to its attractive color and unique sweet/sour taste. Recent studies have highlighted the nutritional value and health-related benefits of CB. CB has special biological characteristics of evergreen, special aroma, dioecious, nodulation, nitrogen fixation. Moreover, the fruits, leaves, and bark of CB plants harbor a number of bioactive compounds including proanthocyanidins, flavonoids, vitamin C, phenolic acids, and anthocyanins that have been linked to the anti-cancer, anti-oxidant, anti-inflammatory, anti-obesity, anti-diabetic, and neuroprotective properties and to the treatment of cardiovascular and cerebrovascular diseases. The CB fruits have been used to produce a range of products: beverages, foods, and washing supplies. Future CB-related product development is thus expected to further leverage the health-promoting potential of this valuable ecological resource. The present review provides an overview of the botanical characteristics, processing, nutritional value, health-related properties, and applications of CB in order to provide a foundation for further research and development.

Concentrated extract of Prunus mume fruit exerts dual effects in 3T3-L1 adipocytes by inhibiting adipogenesis and inducing beiging/browning

Background

The fruit Prunus mume has beneficial effects in the treatment of obesity and metabolic syndrome. However, its mechanism of action is unclear.

Objective

We assessed the effect of a concentrated water extract of P. mume fruit (CEPM) on adipogenesis and beiging/browning in 3T3-L1 cells.

Methods

The cell viability was determined by MTT assay. Lipid accumulation was assessed with Oil Red O (ORO) staining under different concentrations of CEPM. The effects of CEPM treatment during differentiation on beiging/browning and mitochondrial biogenesis in 3T3-L1 cells were investigated.

Results

CEPM treatment suppressed differentiation and decreased lipid accumulation by downregulating the expression of key adipogenic genes, including PPARγ, C/EBPα, SREBP-1c, FAS, and perilipin A. In contrast, CEPM treatment increased the mitochondrial DNA (mtDNA) content and mRNA levels of mitochondrial biogenesis genes, including NAMPT, Nrf1, Nrf2, and CPT1α, and reduced reactive oxygen species levels. Importantly, CEPM increased the expression of brown/beige hallmark genes (Pgc-1α, Ucp1, Cidea, Cox7α1, Cox8b, Cd137, and Pdk-4), as well as proteins (UCP1, PGC-1α, NRF1, TBX1, and CPT1α). The high-performance liquid chromatography (HPLC) analysis reveals that CEPM contains mumefural, naringin, 5-HMF, citric acid, caffeic acid, and hesperidin.

Conclusion

The first evidence we provided showed that CEPM has a dual role in 3T3-L1 cells inhibiting adipogenesis and promoting beiging/browning, and hence, could be a potential agent in the fight against obesity.

Anti-Hyperglycemic Effects of Refined Fractions from Cyclocarya paliurus Leaves on Streptozotocin-Induced Diabetic Mice

To identify the chemical components responsible for the anti-hyperglycemic effect of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae) leaves, an ethanol extract (CPE) and a water extract (CPW) of C. paliurus leaves, as well as their total flavonoids (CPF), triterpenoids (CPT) and crude polysaccharides (CPP), were prepared and assessed on streptozotocin (STZ)-induced diabetic mice. After being orally administrated once a day for 24 days, CPF (300 mg/kg), CPP (180 mg/kg), or CPF+CPP (300 mg/kg CPF + 180 mg/kg CPP) treatment reversed STZ-induced body weight and muscle mass losses. The glucose tolerance tests and insulin tolerance tests suggested that CPF, CPP, and CPF+CPP showed anti-hyperglycemic effect in STZ-induced diabetic mice. Furthermore, CPF enhances glucose-stimulated insulin secretion in MIN6 cells and insulin-stimulated glucose uptake in C2C12 myotubes. CPF and CPP suppressed inflammatory cytokine levels in STZ-induced diabetic mice. Additionally, CPF and CPP improved STZ-induced diabetic nephropathy assessed by H&E staining, blood urea nitrogen content, and urine creatinine level. The molecular networking and Emperor analysis results indicated that CPF showed potential anti-hyperglycemic effects, and HPLC–MS/MS analysis indicated that CPF contains 3 phenolic acids and 9 flavonoids. In contrast, CPT (650 mg/kg) and CPC (300 mg/kg CPF + 180 mg/kg CPP + 650 mg/kg CPT) did not show anti-hyperglycemic effect. Taken together, polysaccharides and flavonoids are responsible for the anti-hyperglycemic effect of C. paliurus leaves, and the clinical application of C. paliurus need to be refined.

Recent development in zebrafish model for bioactivity and safety evaluation of natural products

The zebrafish is a species of freshwater fish, popular in aquariums and laboratories. Several advantageous features have facilitated zebrafish to be extensively utilized as a valuable vertebrate model in the lab. It has been well-recognized that natural products possess multiple health benefits for humans. With the increasing demand for natural products in the development of functional foods, nutraceuticals, and natural cosmetics, the zebrafish has emerged as an unprecedented tool for rapidly and economically screening and identifying safe and effective substances from natural products. This review first summarized the key factors for the management of zebrafish in the laboratory, followed by highlighting the current progress on the establishment and applications of zebrafish models in the bioactivity evaluation of natural products. In addition, the zebrafish models used for assessing the potential toxicity or health risks of natural products were involved as well. Overall, this review indicates that zebrafish are promising animal models for the bioactivity and safety evaluation of natural products, and zebrafish models can accelerate the discovery of novel natural products with potential health functions.

Treasuring the computational approach in medicinal plant research

Medicinal plants serve as a valuable source of secondary metabolites since time immemorial. Computational Research in 21st century is giving more attention to medicinal plants for new drug design as pharmacological screening of bioactive compound was time consuming and expensive. Computational methods such as Molecular Docking, Molecular Dynamic Simulation and Artificial intelligence are significant Insilico tools in medicinal plant research. Molecular docking approach exploits the mechanism of potential phytochemicals into the target active site to elucidate its interactions and biological therapeutic properties. MD simulation illuminates the dynamic behavior of biomolecules at atomic level with fine quality representation of biomolecules. Dramatical advancement in computer science is illustrating the biological mechanism via these tools in different diseases treatment. The advancement comprises speed, the system configuration, and other software upgradation to insights into the structural explanation and optimization of biomolecules. A probable shift from simulation to artificial intelligence has in fact accelerated the art of scientific study to a sky high. The most upgraded algorithm in artificial intelligence such as Artificial Neural Networks, Deep Neural Networks, Neuro-fuzzy Logic has provided a wide opportunity in easing the time required in classical experimental strategy. The notable progress in computer science technology has paved a pathway for understanding the pharmacological functions and creating a roadmap for drug design and development and other achievement in the field of medicinal plants research. This review focus on the development and overview in computational research moving from static molecular docking method to a range of dynamic simulation and an advanced artificial intelligence such as machine learning.

Neuroprotective and Anti-inflammatory Ditetrahydrofuran-Containing Diarylheptanoids from Tacca chantrieri

Three new dimeric diarylheptanoids, taccachanfurans A-C (1-3), a new monomeric diarylheptanoid, taccachannoid A (4), and four known diarylheptanoids (5-8) were isolated from the EtOH extract of the rhizomes of Tacca chantrieri. Their structures were established on the basis of comprehensive spectroscopic data analysis. The absolute configuration of taccachanfuran A (1) was confirmed by single-crystal X-ray diffraction. All the diarylheptanoid dimers contain a ditetrahydrofuran moiety, which has not been described previously for diarylheptanoid compounds. A plausible biosynthetic pathway for the diarylheptanoid dimers is proposed. Compounds 2-4 showed significant neuroprotective activity against Aβ_25-35-induced damage in SH-SY5Y cells at the concentrations of 10 and 1 μM. Compounds 3, 4, 6, 7, and 8 showed anti-inflammatory activity in LPS-stimulated murine microglial BV-2 cells at the concentrations of 10 and 1 μM.

The "irisin system": From biological roles to pharmacological and nutraceutical perspectives

The scientific interest in irisin, a myokine discovered in 2012, has grown exponentially in recent years. Irisin, which is mainly produced in skeletal muscle, influences the browning process of adipose tissue and lipid and energy metabolism. Recent discoveries highlight that the potential of this hormone may have been underestimated. In the first part of this review, reports on irisin structure and molecules involved in its metabolic pathway are shown. Furthermore, data related to unclear aspects are also reported: distribution, different gene expression of its precursors in different tissues, physiological levels of circulating irisin, and pharmacokinetic and pharmacodynamic profile. The second part of this work focuses on exogenous stimuli and pharmacological agents which regulate the metabolic pathway of irisin and its serum concentration. In addition to physical exercise and exposure to low temperatures, which were early recognized as exogenous stimuli able to promote the production of this myokine, preclinical and clinical evidence demonstrates the ability of natural and synthetic molecules to interfere with this metabolic pathway. Current experimental data on irisin cannot dissolve all doubts related to this interesting molecule, but they certainly underline its potential for therapeutic purposes. Thus, identification of new pharmacological tools able to act on the irisin pathway is a challenging issue for biomedical research.

Phytochemicals with Added Value from Morella and Myrica Species

Terrestrial plants, due to their sessile nature, are highly exposed to environmental pressure and therefore need to produce very effective molecules that enable them to survive all the threats. Myrica and Morella (Myricaceae) are taxonomically close genera, which include species of trees or shrubs with edible fruits that exhibit relevant uses in traditional medicine. For instance, in Chinese or Japanese folk medicine, they are used to treat diarrhea, digestive problems, headache, burns, and skin diseases. A wide array of compounds isolated from different parts of Myrica and/or Morella species possess several biological activities, like anticancer, antidiabetic, anti-obesity, and cardio-/neuro-/hepatoprotective activities, both in vitro and in vivo, with myricanol, myricitrin, quercitrin, and betulin being the most promising. There are still many other compounds isolated from both genera whose biological activities have not been evaluated, which represents an excellent opportunity to discover new applications for those compounds and valorize Morella/Myrica species.

Chrysophanol Alleviates Metabolic Syndrome by Activating the SIRT6/AMPK Signaling Pathway in Brown Adipocytes

Chrysophanol, a primary active ingredient of Cassia mimosoides Linn or Rhei radix et rhizoma, has various pharmacological properties, including anticancer, antidiabetic, and anti-inflammatory, as well as blood lipid regulation. However, whether chrysophanol can mitigate obesity, and its underlying mechanisms remains unclear. This study investigated whether chrysophanol effects energy metabolism in high-fat diet- (HFD-) induced obese mice and fat-specific Sirtuin 6- (SIRT6-) knockout (FKO) mice, targeting the SIRT6/AMPK signaling pathway in brown and white fat tissue. Our results showed that chrysophanol can effectively inhibit lipid accumulation in vitro and reduce mice's body weight, improve insulin sensitivity and reduced fat content of mice, and induce energy consumption in HFD-induced obese mice by activating the SIRT6/AMPK pathway. However, a treatment with OSS-128167, an SIRT6 inhibitor, or si-SIRT6, SIRT6 target specific small interfering RNA, in vitro blocked chrysophanol inhibition of lipid accumulation. Similar results were obtained when blocking the AMPK pathway. Moreover, in the HFD-induced obese model with SIRT6 FKO mice, histological analysis and genetic test results showed that chrysophanol treatment did not reduce lipid droplets and upregulated the uncoupling protein 1 (UCP1) expression. Rather, it upregulated the expression of thermogenic genes and activated white fat breakdown by inducing phosphorylation of adenosine 5′-monophosphate- (AMP-) activated protein kinase (AMPK), both in vitro and in vivo. OSS-128167 or si-SIRT6 blocked chrysophanol's upregulation of peroxisome proliferator-activated receptor-γ coactivator-1α (Pgc-1α) and Ucp1 expression. In conclusion, this study demonstrated that chrysophanol can activate brown fat through the SIRT6/AMPK pathway and increase energy consumption, insulin sensitivity, and heat production, thereby alleviating obesity and metabolic disorders.

SIRT3 Acts as a Positive Autophagy Regulator to Promote Lipid Mobilization in Adipocytes via Activating AMPK

Obesity is increasing at an alarming rate worldwide, which is characterized by the excessive accumulation of triglycerides in adipocytes. Emerging evidence has demonstrated that macroautophagy and chaperone-mediated autophagy (CMA) regulate lipid mobilization and play a key role in energy balance. Sirtuin 3 (SIRT3) is an NAD⁺-dependent deacetylase, which is important in regulating macroautophagy and lipid metabolism. It is still unknown whether SIRT3 modulates macroautophagy and CMA in adipocytes. The current study found that macroautophagy was dynamically regulated during 3T3-L1 adipocyte differentiation, which coincided with SIRT3 expression. In mature adipocytes, overexpression of SIRT3 activated macroautophagy, mainly on lipid droplets (LDs), through activating the AMP-activated protein kinase (AMPK)-unc-51-like kinase 1 (ULK1) pathway, which in turn resulting in smaller LD size and reduced lipid accumulation. Moreover, SIRT3 overexpression induced the formation of perilipin-1 (PLN1)-heat shock cognate 71 kDa protein (HSC70)-lysosome-associated membrane protein 2 (LAMP2) complex, to activate CMA and cause the instability of LDs in adipocytes. In summary, we found SIRT3 is a positive regulator of macroautophagy and CMA in adipocytes, which might be a promising therapeutic target for treatment of obesity and its related metabolic dysfunction.

Tricarabrols A–C, three anti-inflammatory sesquiterpene lactone trimers featuring a methylene-tethered linkage from Carpesium faberi

Three anti-inflammatory trimeric compounds constructed from carabrol-type sesquiterpenoids through a methylene-tethered linkage were characterized from Carpesium faberi.

α-Mangostin remodels visceral adipose tissue inflammation to ameliorate age-related metabolic disorders in mice

Low-grade chronic adipose tissue inflammation contributes to the onset and development of aging-related insulin resistance and type 2 diabetes. In the current study, α-mangostin, a xanthone isolated from mangosteen (Garcinia mangostana), was identified to ameliorate lipopolysaccharides-induced acute adipose tissue inflammation in mice, by reducing the expression of pro-inflammatory cytokines and chemokines. In a cohort of young (3 months) and old (18-20 months) mice, α-mangostin mitigated aging-associated adiposity, hyperlipidemia, and insulin resistance. Further study showed that α-mangostin alleviated aging-related adipose tissue inflammation by reducing macrophage content and shifting pro-inflammatory macrophage polarization. Moreover, α-mangostin protected the old mice against liver injury through suppressing the secretion of microRNA-155-5p from macrophages. The above results demonstrated that α-mangostin represents a new scaffold to alleviate adipose tissue inflammation, which might be a novel candidate to treat aging-related metabolic disorders.

Myricanol modulates skeletal muscle-adipose tissue crosstalk to alleviate high-fat diet-induced obesity and insulin resistance

BACKGROUND AND PURPOSE

Skeletal muscle is the predominant site for glucose disposal and fatty acid consumption. Emerging evidence indicates that the crosstalk between adipose tissue and skeletal muscle is critical in maintaining insulin sensitivity and lipid homeostasis. The current study was designed to investigate whether myricanol improves insulin sensitivity and alleviates adiposity through modulating skeletal muscle-adipose tissue crosstalk.

EXPERIMENTAL APPROACH

The therapeutic effect of myricanol was evaluated on palmitic acid (PA)-treated C2C12 myotubes and high-fat diet (HFD)-fed mice. The crosstalk between myotubes and adipocytes was evaluated using Transwell assay. The cellular lipid content was examined by Nile red staining. The mitochondrial content was assessed by MitoTracker Green staining and citrate synthase activity, and the mitochondrial function was examined by Seahorse assay. Expression of mitochondria-related and insulin signalling pathway proteins was analysed by Western blot, and the irisin level was determined by elisa kit.

KEY RESULTS

Myricanol increased mitochondrial quantity and function through activating AMP-activated protein kinase, resulting in reduced lipid accumulation and enhanced insulin-stimulated glucose uptake, in PA-treated C2C12 myotubes. Furthermore, myricanol stimulated irisin production and secretion from myotubes to reduce lipid content in 3T3-L1 adipocytes. In HFD-fed mice, myricanol treatment alleviated adiposity and insulin resistance through enhancing lipid utilization and irisin production in skeletal muscle and inducing browning of inguinal fat.

CONCLUSIONS AND IMPLICATIONS

Myricanol modulates skeletal muscle-adipose tissue crosstalk, to stimulate browning of adipose tissue and improve insulin sensitivity in skeletal muscle. Myricanol might be a potential candidate for treating insulin resistance and obesity.

Natural constituents from food sources: potential therapeutic agents against muscle wasting

Skeletal muscle wasting is highly correlated with not only reduced quality of life but also higher morbidity and mortality. Although an increasing number of patients are suffering from various kinds of muscle atrophy and weakness, there is still no effective therapy available, and skeletal muscle is considered as an under-medicated organ. Food provided not only essential macronutrients but also functional substances involved in the modulation of the physiological systems of our body. Natural constituents from commonly consumed dietary plants, either extracts or compounds, have attracted more and more attention to be developed as agents for preventing and treating muscle wasting due to their safety and effectiveness, as well as structural diversity. This review provides an overview of the mechanistic aspects of muscle wasting, and summarizes the extracts and compounds from food sources as potential therapeutic agents against muscle wasting.

Separation and Lipid Inhibition Effects of a Novel Decapeptide from Chlorella pyenoidose

A novel lipid inhibition peptide Leu-Leu-Val-Val-Try-Pro-Trp-Thr-Gln-Arg (PP1) (MW 1274.53 Da) was obtained from Chlorella pyenoidose using enzymatic hydrolysis, gel filtration chromatography, and LC–MS/MS. Its lipid inhibition effects indicated that the synthetic peptide PP1 exhibits a good inhibitory effect against porcine pancreatic lipase (PL) (47.95%) at 200 μg/mL, which could be attributed to its hydrogen binding into catalytic sites of PL (Ser153, Asp177, and His 264) by docking analysis. Furthermore, in 3T3-L1 cells, the synthetic PP1 remarkedly decreased the accumulation of intracellular triacylglycerol (27.9%, 600 μg/mL), which carried a similar consequence as the positive drug simvastatin (24.1%, 10 μM). Western blot revealed that PP1 inhibited the lipid accumulation and fatty acid synthesis in 3T3-L1 adipocytes in two pathways, primarily: nonalcoholic fatty liver disease (NAFLD) pathway (C/EBPα, SREBP-1c, AMPKα) and AMPK signaling pathway (SREBP-1c, PPARγ, AMPKα). In short, these results support that PP1 can be used as a potential agent against obesity.

SIRT3 promotes lipophagy and chaperon-mediated autophagy to protect hepatocytes against lipotoxicity

Lipophagy is a lysosomal lipolytic pathway that complements the actions of cytosolic neutral lipases. Chaperon-mediated autophagy (CMA) triggers lipid droplets (LDs) breakdown, to initiate lipolysis via either cytosolic lipases or macroautophagy. SIRT3, a mitochondrial NAD⁺-dependent deacetylase, regulates the acetylation status and activity of many substrates involving in energy metabolism. However, the role of SIRT3 in regulating lipophagy is controversial. The current study showed that SIRT3 expression was decreased and the macroautophagy flux was blocked in the primary hepatocytes from high-fat diet fed mice and P/O (palmitic acid and oleic acid mixture) treated AML12 mouse hepatocytes, compared with the corresponding controls. SIRT3 overexpression promoted macroautophagy in LDs from P/O-treated hepatocytes through activating AMP-activated protein kinase (AMPK) and unc-51-like kinase 1, to boost LDs digestion. Gain of SIRT3 expression stimulated the formation of lysosome-associated membrane protein 2A (LAMP-2A)-heat shock cognate 71 kDa protein (HSC70)-perilipin-2 (PLN2) complex, to promote CMA process and reduce the stability of LDs in hepatocytes. Moreover, SIRT3 reduced the expression of stearoyl-CoA desaturase 1, to suppress lipogenesis. In addition, SIRT3 overexpression promoted LDs dispersion on detyrosinated microtubules, and directly deacetylated long-chain acyl-CoA dehydrogenase to enhance mitochondrial energetics. Taken together, SIRT3 ameliorates lipotoxicity in hepatocytes, which might be a potential target for the treatment of nonalcoholic fatty liver disease.

Triterpenoids from Cyclocarya paliurus that Enhance Glucose Uptake in 3T3-L1 Adipocytes

Four previously undescribed compounds, including three rarely occurring seco-dammarane triterpenoid glycosides and a pentacyclic triterpenic acid, were isolated from a 70% ethanol extract of the leaves of Cyclocarya paliurus (Juglandaceae), along with eleven known triterpenoids. Their structures were determined by spectroscopic techniques, including 2D NMR and HRESIMS, as well as chemical methods. Among them, several triterpenoids enhanced insulin stimulated glucose uptake in both 3T3-L1 adipocytes and C2C12 myotubes. Furthermore, compound 1 dose-dependently increased glucose uptake through activating AMP-activated protein kinase (AMPK)-p38 pathway. Collectively, triterpenoids from C. paliurus could be developed as insulin sensitizers, which might have therapeutic potential for insulin resistance and hyperglycemia.