Punica granatum L. leaf extract enhances stress tolerance and promotes healthy longevity through HLH-30/TFEB, DAF16/FOXO, and SKN1/NRF2 crosstalk in Caenorhabditis elegans.

BACKGROUND: Punica granatum L., commonly known as pomegranate, is renowned for its health benefits, primarily associated with the consumption of its fruit and seeds. However, its non-edible parts, including leaves, have been used in traditional medicine as a remedy with anti-inflammatory and anti-diabetic properties. Considering the abundance of bioactive compounds, predominantly flavonols, flavones, and tannins P. granatum leaf (PGL) extract holds potential as health-promoting agent. Yet, its effect on longevity and healthspan remains largely unexplored. PURPOSE: Our study aims to explore the potential of PGL extract to enhance healthspan and ameliorate age-related frailty in Caenorhabditis elegans. Additionally, we seek to elucidate its effect on the molecular signaling networks associated with stress resistance and longevity. METHODS: After characterizing the extract metabolite profile by NMR spectroscopy, phenotypic and stress analyses were performed. In order to establish the molecular mechanism of action, the involvement of signaling pathways key to longevity were investigated by means of real-time quantitative PCR (RT-qPCR) and the use of transgenic strains (MIR13, MAH240, LD1, and OH16024). In addition, the effect of PGL on metabolism and lipid accumulation, as well as mitochondrial homeostasis, was examined. RESULTS: The PGL extract supplementation significantly enhanced stress resistance and extended the lifespan of C. elegans. Additionally, it improved locomotion, as well as metabolic and mitochondrial functions, indicating an overall improvement in health. The molecular mechanisms highlight the coordinated regulation of stress response, metabolic homeostasis, and longevity signaling pathways. Specifically, our results demonstrate the essential roles of HLH-30/TFEB, in conjunction with DAF-16/FOXO and SKN-1/NRF2, as mediators of the PGL extract effect on healthspan. CONCLUSION: Our findings emphasize the potential of PGL extract to ameliorate age-related decline, induce longevity and further enhance healthspan. Given the diverse effects on the molecular network associated with stress-adaptations, longevity and metabolic control, PGL extract might become a promising natural product with a particular importance to the field of gerontology.

Maackiain Mimics Caloric Restriction through aak-2-Mediated Lipid Reduction in Caenorhabditis elegans.

Obesity prevalence is becoming a serious global health and economic issue and is a major risk factor for concomitant diseases that worsen the quality and duration of life. Therefore, the urgency of the development of novel therapies is of a particular importance. A previous study of ours revealed that the natural pterocarpan, maackiain (MACK), significantly inhibits adipogenic differentiation in human adipocytes through a peroxisome proliferator-activated receptor gamma (PPARγ)-dependent mechanism. Considering the observed anti-adipogenic potential of MACK, we aimed to further elucidate the molecular mechanisms that drive its biological activity in a Caenorhabditis elegans obesity model. Therefore, in the current study, the anti-obesogenic effect of MACK (25, 50, and 100 µM) was compared to orlistat (ORST, 12 µM) as a reference drug. Additionally, the hybrid combination between the ORST (12 µM) and MACK (100 µM) was assessed for suspected synergistic interaction. Mechanistically, the observed anti-obesogenic effect of MACK was mediated through the upregulation of the key metabolic regulators, namely, the nuclear hormone receptor 49 (nhr-49) that is a functional homologue of the mammalian PPARs and the AMP-activated protein kinase (aak-2/AMPK) in C. elegans. Collectively, our investigation indicates that MACK has the potential to limit lipid accumulation and control obesity that deserves future developments.

Anti-Adipogenic Activity of Rhaponticum carthamoides and Its Secondary Metabolites.

Besides their common use as an adaptogen, Rhaponticum carthamoides (Willd.) Iljin. rhizome and its root extract (RCE) are also reported to beneficially affect lipid metabolism. The main characteristic secondary metabolites of RCE are phytoecdysteroids. In order to determine an RCE's phytoecdysteroid profile, a novel, sensitive, and robust high-performance thin-layer chromatography (HPTLC) method was developed and validated. Moreover, a comparative analysis was conducted to investigate the effects of RCE and its secondary metabolites on adipogenesis and adipolysis. The evaluation of the anti-adipogenic and lipolytic effects was performed using human Simpson-Golabi-Behmel syndrome cells, where lipid staining and measurement of released glycerol and free fatty acids were employed. The HPTLC method confirmed the presence of 20-hydroxyecdysone (20E), ponasterone A (PA), and turkesterone (TU) in RCE. The observed results revealed that RCE, 20E, and TU significantly reduced lipid accumulation in human adipocytes, demonstrating their anti-adipogenic activity. Moreover, RCE and 20E were found to effectively stimulate basal lipolysis. However, no significant effects were observed with PA and TU applications. Based on our findings, RCE and 20E affect both lipogenesis and lipolysis, while TU only restrains adipogenesis. These results are fundamental for further investigations.

Targeting PI3K/AKT signaling pathway in obesity.

Obesity is a disorder with an increasing prevalence, which impairs the life quality of patients and intensifies societal health care costs. The development of safe and innovative prevention strategies and therapeutic approaches is thus of great importance. The complex pathophysiology of obesity involves multiple signaling pathways that influence energy metabolism in different tissues. The phosphatidylinositol 3-kinases (PI3K)/protein kinase B (AKT) pathway is critical for the metabolic homeostasis and its function in insulin-sensitive tissues is described in the context of health, obesity and obesity-related complications. The PI3K family participates in the regulation of diverse physiological processes including but not limited to cell growth, survival, differentiation, autophagy, chemotaxis, and metabolism depending on the cellular context. AKT is downstream of PI3K in the insulin signaling pathway, and promotes multiple cellular processes by targeting a plethora of regulatory proteins that control glucose and lipid metabolism. Natural products are essential for prevention and treatment of many human diseases, including obesity. Anti-obesity natural compounds effect multiple pathophysiological mechanisms involved in obesity development. Numerous recent preclinical studies reveal the advances in using plant secondary metabolites to target the PI3K/AKT signaling pathway for obesity management. In this paper the druggability of PI3K as a target for compounds with anti-obesity potential is evaluated. Perspectives on the strategies and limitations for clinical implementation of obesity management using natural compounds modulating the PI3K/AKT pathway are suggested.

Icariin Improves Stress Resistance and Extends Lifespan in Caenorhabditis elegans through hsf-1 and daf-2-Driven Hormesis.

Aging presents an increasingly significant challenge globally, driven by the growing proportion of individuals aged 60 and older. Currently, there is substantial research interest in pro-longevity interventions that target pivotal signaling pathways, aiming not only to extend lifespan but also to enhance healthspan. One particularly promising approach involves inducing a hormetic response through the utilization of natural compounds defined as hormetins. Various studies have introduced the flavonoid icariin as beneficial for age-related diseases such as cardiovascular and neurodegenerative conditions. To validate its potential pro-longevity properties, we employed Caenorhabditis elegans as an experimental platform. The accumulated results suggest that icariin extends the lifespan of C. elegans through modulation of the DAF-2, corresponding to the insulin/IGF-1 signaling pathway in humans. Additionally, we identified increased resistance to heat and oxidative stress, modulation of lipid metabolism, improved late-life healthspan, and an extended lifespan upon icariin treatment. Consequently, a model mechanism of action was provided for icariin that involves the modulation of various players within the stress-response network. Collectively, the obtained data reveal that icariin is a potential hormetic agent with geroprotective properties that merits future developments.

Betulinic acid counteracts the lipid accumulation in Caenorhabditis elegans by modulation of nhr-49 expression.

Obesity is an ingrained health problem with а multifactorial origin and а long history, thereby innovations in the treatment strategies are of great importance. In the search of a remedy for excessive weight gain, we have directed our investigations to phytochemicals as valuable bioactive compounds. Betulinic acid (BA), among the other triterpenoids, is known for its anti-inflammatory and anti-neoplastic properties. In addition, a previous study of ours has demonstrated а potent anti-adipogenic effect of BA in human adipocytes. Therefore, we aimed here to further verify the anti-obesogenic effect of BA in vivo in Caenorhabditis elegans. Induction of lipid accumulation in the nematodes was modelled with glucose-supplemented media, followed by treatment with BA (10-50 µM) or orlistat (12 µM) as a control anti-obesity medication. Oil red O and Nile red staining were applied to provide quantification of accumulated lipids. Analysis of the relative expression of genes, related to lipid metabolism suggested molecular mechanism of lipid-reducing action of BA in C. elegans. Treatment of nematodes with BA significantly decreased the lipid accumulation, downregulated desaturases involved in lipogenesis (fat-5, fat-6 and fat-7), modulated key transcription factors (nhr-49 and hlh-11) and microRNAs (miR-60, lin-4, let-7 and miR-786) associated with the lipid metabolism. Collectively, the current research provides additional insight on the molecular mechanism of the BA's anti-obesogenic effect in vivo. Furthermore, it validates the potential of BA as a candidate compound in obesity management by reducing lipid accumulation.

Chemical Composition and Histochemical Localization of Essential Oil from Wild and Cultivated Rhaponticum carthamoides Roots and Rhizomes.

Rhaponticum carthamoides (Willd.) Iljin is not only a source of phytosteroids and flavonoids, but is also source of essential oil (EO). This study evaluated the volatile metabolic constituents and histochemical localization of root and rhizome essential oils (EOs) from R. carthamoides populations wild-grown in Russia and cultivated in Bulgaria. The performed histochemical analysis confirmed the presence of lipophilic substances in the secretory ducts of the examined roots and rhizomes. Both EOs were obtained by hydrodistillation and further analyzed by gas chromatography with mass detection. The results showed differences between the chemical compositions of both EOs. Forty-six components were tentatively identified in R. carthamoides oil from the wild population, with ß-selinene (4.77%), estragole (6.32%), D-carvone (6.37%), cyperene (8.78%), and ledene oxide (11.52%) being the major constituents. In the EO isolated from cultivated R. carthamoides, twenty-three compounds were tentatively identified, with humulene (7.68%), ß-elemene (10.76%), humulene-1,2-epoxide (11.55%), ledene oxide (13.50%), and δ-elemene (19.08%) predominating. This is the first report describing the histolocalization and chemical profile of EO from R. carthamoides cultivated in Bulgaria. Further research on the cultivation of R. carthamoides in Bulgaria would affect the relationship between its chemical composition and pharmacological effects.

Anti-adipogenic activity of maackiain and ononin is mediated via inhibition of PPARγ in human adipocytes.

Obesity is a global health burden for which we do not yet have effective treatments for prevention or therapy. Plants are an invaluable source of bioactive leads possessing anti-adipogenic potential. Ethnopharmacological use of Ononis spinosa L. roots (OSR) for treatment of obesity and metabolic disorders requires а scientific rationale. The current study examined the anti-adipogenic capacity of OSR and its secondary metabolites ononin (ONON) and maackiain (MACK) in human adipocytes as an in vitro model of obesity. Both ONON and MACK diminished lipid accumulation during adipocyte differentiation. Molecular docking analysis exposed the potential interactions between MACK or ONON and target regulatory adipogenic proteins. Furthermore, results from an RT-qPCR analysis disclosed significant upregulation of AMPK by MACK and ONON treatment. In addition, ONON increased SIRT1, PI3K and ACC mRNA expression, while MACK notably downregulated CEBPA, AKT, SREBP1, ACC and ADIPOQ. The protein level of PI3K, C/EBPα, PPARγ and adiponectin was reduced upon MACK treatment in a concentration-dependent manner. Similarly, ONON suppressed PI3K, PPARγ and adiponectin protein abundance. Finally, our study provides evidence that ONON exerts anti-adipogenic effect by upregulation of SIRT1 and inhibition of PI3K, PPARγ and adiponectin, while MACK induced strong inhibitory effect on adipogenesis via hampering PI3K, PPARγ/C/EBPα signaling and anti-lipogenic effect through downregulation of SREBP1 and ACC. Even though OSR does not hamper adipogenic differentiation, it could be exploited as a source of natural leads with anti-adipogenic potential. The multidirectional mechanism of action of MACK warrant further validation in the context of in vivo obesity models.

Anti-Adipogenic Effect of Alchemilla monticola is Mediated Via PI3K/AKT Signaling Inhibition in Human Adipocytes.

Obesity is a persistent and continuously expanding social health concern. Excessive fat mass accumulation is associated with increased risk of chronic diseases including diabetes, atherosclerosis, non-alcoholic steatohepatitis, reproductive dysfunctions and certain types of cancer. Alchemilla monticola Opiz. is a perennial plant of the Rosaceae family traditionally used to treat inflammatory conditions and as a component of weight loss herbal mixtures. In the search for bioactive leads with potential anti-adipogenic effect from A. monticola extract (ALM), we have employed nuclear magnetic resonance (NMR) based metabolomics to obtain data for the phytochemical profile of the extract. Further, molecular docking simulation was performed against key adipogenic targets for selected pure compounds, present in the ALM extract. Evaluation of the biological activity was done in human adipocytes exposed to ALM (5, 10 and 25 µg/ml), pure astragalin (AST) or quercitrin (QUE) both at the concentrations of 5, 10 and 25 µM. Investigation of the molecular pathways involved was performed through real-time quantitative PCR and Western blot analyses. According to the docking predictions strong putative affinity was revealed for both AST and QUE towards peroxisome proliferator-activated receptor gamma (PPARγ) and phosphoinositide 3-kinase (PI3K). Assessment of the intracellular lipid accumulation revealed anti-adipogenic activity of ALM. Correspondingly, the expression of the adipogenic genes CCAAT/enhancer-binding protein alpha (CEBPA) and PPARG was downregulated upon ALM and AST treatment. The Western blotting results exposed protein kinase B (AKT), PI3K and PPARγ as targets for the inhibitory effect of ALM and AST on adipogenesis. Collectively, we provide a broader insight of the phytochemical composition of A. monticola. Additionally, we demonstrate the anti-adipogenic effect of ALM and its active compound AST in human adipocytes. Furthermore, PI3K/AKT signaling pathway is identified to mediate the ALM anti-adipogenic action. Hence, the ALM extract and its secondary metabolite AST are worth further exploration as potentially active agents in obesity management.

Metabolomics and health: from nutritional crops and plant-based pharmaceuticals to profiling of human biofluids.

During the past decade metabolomics has emerged as one of the fastest developing branches of "-omics" technologies. Metabolomics involves documentation, identification, and quantification of metabolites through modern analytical platforms in various biological systems. Advanced analytical tools, such as gas chromatography-mass spectrometry (GC/MS), liquid chromatography-mass spectroscopy (LC/MS), and non-destructive nuclear magnetic resonance (NMR) spectroscopy, have facilitated metabolite profiling of complex biological matrices. Metabolomics, along with transcriptomics, has an influential role in discovering connections between genetic regulation, metabolite phenotyping and biomarkers identification. Comprehensive metabolite profiling allows integration of the summarized data towards manipulation of biosynthetic pathways, determination of nutritional quality markers, improvement in crop yield, selection of desired metabolites/genes, and their heritability in modern breeding. Along with that, metabolomics is invaluable in predicting the biological activity of medicinal plants, assisting the bioactivity-guided fractionation process and bioactive leads discovery, as well as serving as a tool for quality control and authentication of commercial plant-derived natural products. Metabolomic analysis of human biofluids is implemented in clinical practice to discriminate between physiological and pathological state in humans, to aid early disease biomarker discovery and predict individual response to drug therapy. Thus, metabolomics could be utilized to preserve human health by improving the nutritional quality of crops and accelerating plant-derived bioactive leads discovery through disease diagnostics, or through increasing the therapeutic efficacy of drugs via more personalized approach. Here, we attempt to explore the potential value of metabolite profiling comprising the above-mentioned applications of metabolomics in crop improvement, medicinal plants utilization, and, in the prognosis, diagnosis and management of complex diseases.

Ziziphus jujuba Mill. leaf extract restrains adipogenesis by targeting PI3K/AKT signaling pathway.

The escalation in the global prevalence of obesity has focused attention on finding novel approaches for its management. Ziziphus jujuba Mill. (ZJL) leaf extract is reported as a traditional remedy for diverse pathological conditions, including obesity. The present study investigated whether ZJL affects adipogenic differentiation in human adipocytes. Additionally, following metabolite profiling of the extract, apigenin (APG), betulinic acid (BA) and maslinic acid (MA) were selected for biological activity evaluation. The possible interactions between APG, BA, MA and target proteins with a central role in adipogenesis were assessed through molecular docking. The potential mechanisms of ZJL, APG, BA and MA were identified using transcriptional analysis through real-time quantitative PCR and protein abundance evaluation by Western blotting. The obtained results revealed a concentration-dependent reduction of accumulated lipids after ZJL, BA and MA application. The key adipogenic transcription factors peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT-enhancer-binding protein alpha (C/EBPα) were strongly decreased at a protein level by all treatments. Moreover, the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway was found to be involved in the anti-adipogenic effect of ZJL, APG and BA. Collectively, our findings indicate that ZJL and its pure compounds hampered adipocyte differentiation through PI3K/AKT inhibition. Among the selected compounds, BA exhibits the most promising anti-adipogenic activity. Furthermore, being a complex mixture of phytochemicals, the ZJL extract could be utilized as source of yet unknown bioactive leads with potential implementation in obesity management.

Rosmarinic acid attenuates obesity and obesity-related inflammation in human adipocytes.

Chronic low-grade inflammation is a hallmark of obesity and its related metabolic disorders. At the same time signaling from pro-inflammatory factors such as transforming growth factor beta (TGF-ß) or interleukin 17A (IL-17A) are proposed as crucial for the commitment of fibroblast progenitor cells towards adipogenic differentiation. Modulation of inflammation during adipogenic differentiation is incompletely explored as a potential approach to prevent metabolic disorders. Rosmarinic acid (RA) is a caffeic acid derivative known for its anti-inflammatory effects. Experimental studies of its activity on adipogenic factors or in vivo obesity models are, however, controversial and hence insufficient. Here, we investigated the anti-adipogenic action of RA in human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes. Gene expression levels of key players in adipogenesis and lipid metabolism were assessed. Furthermore, a molecular mechanism of action was proposed. The most prominent effect was found on the translation of C/EBPα, PPARγ and adiponectin, as well as on the modulation of TGF1B and IL17A. Interestingly, involvement of NRF2 signaling was identified upon RA treatment. In summary, our findings indicate that RA prevents inflammation and excessive lipid accumulation in human adipocytes. Data from the molecular analysis demonstrate that RA has potential for treatment of obesity and obesity-related inflammation.

Caffeic and Chlorogenic Acids Synergistically Activate Browning Program in Human Adipocytes: Implications of AMPK- and PPAR-Mediated Pathways.

Caffeic acid (CA) and chlorogenic acid (CGA) are phenolic compounds claimed to be responsible for the metabolic effects of coffee and tea consumption. Along with their structural similarities, they share common mechanisms such as activation of the AMP-activated protein kinase (AMPK) signaling. The present study aimed to investigate the anti-obesity potential of CA and CGA as co-treatment in human adipocytes. The molecular interactions of CA and CGA with key adipogenic transcription factors were simulated through an in silico molecular docking approach. The expression levels of white and brown adipocyte markers, as well as genes related to lipid metabolism, were analyzed by real-time quantitative PCR and Western blot analyses. Mechanistically, the CA/CGA combination induced lipolysis, upregulated AMPK and browning gene expression and downregulated peroxisome proliferator-activated receptor γ (PPARγ) at both transcriptional and protein levels. The gene expression profiles of the CA/CGA-co-treated adipocytes strongly resembled brown-like signatures. Major pathways identified included the AMPK- and PPAR-related signaling pathways. Collectively, these findings indicated that CA/CGA co-stimulation exerted a browning-inducing potential superior to that of either compound used alone which merits implementation in obesity management. Further, the obtained data provide additional insights on how CA and CGA modify adipocyte function, differentiation and lipid metabolism.

Obesity and NRF2-mediated cytoprotection: Where is the missing link?

The expanding dimensions of the global health crisis of overweight population has defined the term "globesity". Among the most common pathological conditions connected with excessive adiposity are hyperglycemia, insulin resistance, dyslipidemia and hypertension which result in chronic non-communicable diseases (NCD) such as metabolic syndrome (MetS), type 2 diabetes (T2D), and nonalchoholic steatohepatitis (NASH). The contribution of inflammatory-immune reactions in obesity and its related co-morbidities is unequivocal. Increased levels of free fatty acids (FFA), reactive oxygen species (ROS) and reactive nitrogen species (RNS) overloads the homeostatic system resulting in pro-inflammatory adipokines secretion, immune-activation and chronic inflammation in obesity. The cellular mechanisms of defense against oxidative stress are orchestrated by the transcription factor nuclear factor erythroid 2 p45-related factor 2 (NRF2). Excessive oxidative stress in the cell activates NRF2 which upregulates genes encoding major cytoprotective enzymes such as NAD(P)H:quinone oxidoreductase 1 (NQO1), heme oxygenase 1 (HO1), and glutathione S-transferases (GST). The present review aims to clarify the interconnections between chronic inflammation, oxidative overload and NRF2-mediated cytoprotection as potential therapeutic approach in obesity.