Pronuciferine and nuciferine inhibit lipogenesis in 3T3-L1 adipocytes by activating the AMPK signaling pathway

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.

Preparation, pharmacokinetics and anti-obesity effects on dogs of nuciferine liposomes

BACKGROUND

Nuciferine (NUC), a natural compound extracted from lotus leaves, has been proven to have anti-obesity effects. However, the development and application of NUC as an anti-obesity drug in dogs are hindered due to its poor water solubility and low bioavailability.

OBJECTIVE

To promote the development of NUC-related products for anti-obesity in dogs, this study prepared NUC into a liposome formulation and evaluated its characteristics, pharmacokinetics in dogs, and anti-obesity effects on high-fat diet dogs.

METHODS

NUC liposomes were prepared by the ethanol injection method, using NUC, egg lecithin, and β-sitosterol as raw materials. The characteristics and release rate in vitro of liposomes were evaluated by particle size analyser and dialysis method, respectively. The pharmacokinetics in dogs after oral administration of NUC-liposomes was carried out by the high-performance liquid chromatography (HPLC) method. Moreover, we investigated the anti-obesity effect of NUC-liposomes on obese dogs fed with a high-fat diet.

RESULTS

NUC-liposome was successfully prepared, with an EE of (79.31 ± 1.06)%, a particle size of (81.25 ± 3.14) nm, a zeta potential of (-18.75 ± 0.23) mV, and a PDI of 0.175 ± 0.031. The cumulative release rate in vitro of NUC from NUC-liposomes was slower than that of NUC. The T1/2 and relative bioavailability of NUC-liposomes in dogs increased, and CL reduced compared with NUC. In addition, the preventive effect of NUC-liposomes on obesity in high-fat diet dogs is stronger than that of NUC.

CONCLUSIONS

The liposome formulation of NUC was conducive to improve its relative bioavailability and anti-obesity effect in dogs.

Bioprotective Role of Phytocompounds Against the Pathogenesis of Non-alcoholic Fatty Liver Disease to Non-alcoholic Steatohepatitis: Unravelling Underlying Molecular Mechanisms

Non-alcoholic fatty liver disease (NAFLD), with a global prevalence of 25%, continues to escalate, creating noteworthy concerns towards the global health burden. NAFLD causes triglycerides and free fatty acids to build up in the liver. The excessive fat build-up causes inflammation and damages the healthy hepatocytes, leading to non-alcoholic steatohepatitis (NASH). Dietary habits, obesity, insulin resistance, type 2 diabetes, and dyslipidemia influence NAFLD progression. The disease burden is complicated due to the paucity of therapeutic interventions. Obeticholic acid is the only approved therapeutic agent for NAFLD. With more scientific enterprise being directed towards the understanding of the underlying mechanisms of NAFLD, novel targets like lipid synthase, farnesoid X receptor signalling, peroxisome proliferator-activated receptors associated with inflammatory signalling, and hepatocellular injury have played a crucial role in the progression of NAFLD to NASH. Phytocompounds have shown promising results in modulating hepatic lipid metabolism and de novo lipogenesis, suggesting their possible role in managing NAFLD. This review discusses the ameliorative role of different classes of phytochemicals with molecular mechanisms in different cell lines and established animal models. These compounds may lead to the development of novel therapeutic strategies for NAFLD progression to NASH. This review also deliberates on phytomolecules undergoing clinical trials for effective management of NAFLD.

Bitter yet beneficial: The dual role of dietary alkaloids in managing diabetes and enhancing cognitive function

With the rising prevalence of diabetes and its association with cognitive impairment, interest in the use of dietary alkaloids and other natural products has grown significantly. Understanding how these compounds manage diabetic cognitive dysfunction (DCD) is crucial. This comprehensive review explores the etiology of DCD and the effects of alkaloids in foods and dietary supplements that have been investigated as DCD therapies. Data on how dietary alkaloids like berberine, trigonelline, caffeine, capsaicin, 1-deoxynojirimycin, nuciferine, neferine, aegeline, tetramethylpyrazine, piperine, and others regulate cognition in diabetic disorders were collected from PubMed, Research Gate, Web of Science, Science Direct, and other relevant databases. Dietary alkaloids could improve memory in behavioral models and modulate the mechanisms underlying the cognitive benefits of these compounds, including their effects on glucose metabolism, gut microbiota, vasculopathy, neuroinflammation, and oxidative stress. Evidence suggests that dietary alkaloids hold promise for improving cognition in diabetic patients and could open exciting avenues for future research in diabetes management.

An Updated Review on Nelumbo Nucifera Gaertn: Chemical Composition, Nutritional Value and Pharmacological Activities

Nelumbo nucifera Gaertn is a recognised herbal plant in ancient medical sciences. Each portion of the plant leaf, flower, seed and rhizome is utilised for nutritional and medicinal purposes. The chemical compositions like phenol, alkaloids, glycoside, terpenoids and steroids have been isolated. The plant contains various nutritional values like lipids, proteins, amino acids, minerals, carbohydrates, and fatty acids. Traditional medicine confirms that the phytochemicals of plants give significant benefits to the treatment of various diseases such as leukoderma, smallpox, dysentery, haematemesis, coughing, haemorrhage, metrorrhagia, haematuria, fever, hyperlipidaemia, cholera, hepatopathy and hyperdipsia. To verify the traditional claims, researchers have conducted scientific biological in vivo and in vitro screenings, which have exhibited that the plant keeps various notable pharmacological activities such as anticancer, hepatoprotective, antioxidant, antiviral, hypolipidemic, anti-obesity, antipyretic, hypoglycaemic, antifungal, anti-inflammatory and antibacterial activities. This review, summaries the nutritional composition, chemical constituents and biological activities substantiated by the researchers done in vivo and in vitro.

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.

Ilex paraguariensis A.St.-Hil. improves lipid metabolism in high-fat diet-fed obese rats and suppresses intracellular lipid accumulation in 3T3-L1 adipocytes via the AMPK-dependent and insulin signaling pathways

Background

Obesity is closely associated with several chronic diseases, and adipose tissue plays a major role in modulating energy metabolism.

Objective

This study aimed to determine whether Mate, derived from I. paraguariensis A.St.-Hil., ameliorates lipid metabolism in 3T3-L1 adipocytes and high-fat diet (HFD)-fed obese Sprague-Dawley (SD) rats.

Design

3T3-L1 adipocytes were cultured for 7 days, following which intracellular lipid accumulation and expression levels of lipid metabolism-related factors were examined. Dorsomorphin was used to investigate the potential pathways involved, particularly the adenosine monophosphate-activated protein kinase (AMPK)- dependent pathway. Mate was administered to rat HFD-fed obese SD models for 8 consecutive weeks. The expression of lipid metabolism-related factors in the organs and tissues collected from dissected SD rats was evaluated.

Results

Mate suppressed intracellular lipid accumulation in 3T3-L1 adipocytes, increased the protein and gene expression levels of AMPK, hormone sensitive lipase (HSL), calmodulin kinase kinase (CaMKK), liver kinase B1 (LKB1), protein kinase A (PKA), CCAAT/enhancer binding protein β (C/EBPβ), insulin receptor b (IRβ), and insulin receptor substrate 1 (IRS1) (Tyr465), and decreased those of sterol regulatory element binding protein 1C (Srebp1c), fatty acid synthase (FAS), peroxisome-activated receptor γ (PPARγ), and IRS1 (Ser1101). Furthermore, an AMPK inhibitor abolished the effects exerted by Mate on intracellular lipid accumulation and HSL and FAS expression levels. Mate treatment suppressed body weight gain and improved serum cholesterol levels in HFD-fed obese SD rats. Treatment with Mate increased the protein and gene expression levels of AMPK, PKA, Erk1/Erk2 (p44/p42), and uncoupling protein 1 and reduced those of mammalian target of rapamycin, S6 kinase, Srebp1c, ap2, FAS, Il6, Adiponectin, Leptin, and Fabp4 in rat HFD-fed obese SD models.

Discussion and conclusions

Mate suppressed intracellular lipid accumulation in 3T3-L1 adipocytes and improved lipid metabolism in the epididymal adipose tissue of HFD-fed obese SD rats via the activation of AMPK-dependent and insulin signaling pathways.

Anti-Obesity Effect and Mechanism of Chitooligosaccharides Were Revealed Based on Lipidomics in Diet-Induced Obese Mice

Chitooligosaccharide (COS) is a natural product from the ocean, and while many studies have reported its important role in metabolic diseases, no study has systematically elaborated the anti-obesity effect and mechanism of COS. Herein, COSM (MW ≤ 3000 Da) was administered to diet-induced obese mice by oral gavage once daily for eight weeks. The results show that COSM administration reduced body weight; slowed weight gain; reduced serum Glu, insulin, NEFA, TC, TG, and LDL-C levels; increased serum HSL and HDL-C levels; improved inflammation; and reduced lipid droplet size in adipose tissue. Further lipidomic analysis of adipose tissue revealed that 31 lipid species are considered to be underlying lipid biomarkers in COS therapy. These lipids are mainly enriched in pathways involving insulin resistance, thermogenesis, cholesterol metabolism, glyceride metabolism and cyclic adenosine monophosphate (cAMP), which sheds light on the weight loss mechanism of COS. The Western blot assay demonstrated that COSM intervention can improve insulin resistance, inhibit de novo synthesis, and promote thermogenesis and β-oxidation in mitochondria by the AMPK pathway, thereby alleviating high-fat diet-induced obesity. In short, our study can provide a more comprehensive direction for the application of COS in obesity based on molecular markers.

Structure-activity relationship, bioactivities, molecular mechanisms, and clinical application of nuciferine on inflammation-related diseases

Nuciferine aporphine alkaloid mainly exists in Nelumbo nucifera Gaertn and is a beneficial to human health, such as anti-obesity, lowering blood lipid, prevention of diabetes and cancer, closely associated with inflammation. Importantly, nuciferine may contribute to its bioactivities by exerting intense anti-inflammatory activities in multiple models. However, no review has summarized the anti-inflammatory effect of nuciferine. This review critically summarized the information regarding the structure-activity relationships of dietary nuciferine. Moreover, biological activities and clinical application on inflammation-related diseases, such as obesity, diabetes, liver, cardiovascular diseases, and cancer, as well as their potential mechanisms, involving oxidative stress, metabolic signaling, and gut microbiota has been reviewed. The current work provides a better understanding of the anti-inflammation properties of nuciferine against multiple diseases, thereby improving the utilization and application of nuciferine-containing plants across functional food and medicine.

Nuciferine blocks MIB2-mediated CARD6 polyubiquitination and degradation in the amelioration of high fructose-induced liver lipid accumulation

Dietary alkaloid nuciferine isolated from the leaves of Nelumbo nucifera can ameliorate dyslipidemia and liver lipid accumulation, but the underlying mechanism remains unclear. Caspase recruitment domain protein family member 6 (CARD6) is suggested to play an important role in metabolic diseases. This study aimed to investigate the role and the upstream regulator of CARD6 in high fructose-induced liver lipid accumulation and whether and how the anti-lipid accumulation effect of nuciferine was related to CARD6. Herein, we found that high fructose decreased CARD6 expression and increased ASK1 and JNK1/2 phosphorylation in rat livers and hepatocytes, which were attenuated by nuciferine. Furthermore, after the transfection with HA-CARD6, CARD6 siRNA and MIB2 siRNA, the data showed that CARD6 overexpression blocked high fructose-induced upregulation of ASK1 and JNK1/2 phosphorylation as well as lipid accumulation in hepatocytes. CARD6 siRNA reversed the amelioration of nuciferine to high fructose-induced upregulation of ASK1 and JNK1/2 phosphorylation in hepatocyte lipid accumulation. Mechanistically, high fructose upregulated MIB2 expression by interacting with CARD6 and promoting K48-linked CARD6 polyubiquitination and degradation in high fructose-stimulated hepatocytes which were explored by immunoblotting, immunofluorescence, and immunoprecipitation. However, MIB2 siRNA reversed high fructose-induced downregulation of CARD6 and lipid accumulation in hepatocytes. Notably, nuciferine reduced MIB2 expression and thus decreased K48-linked CARD6 polyubiquitination and degradation in the amelioration of high fructose-induced lipid accumulation in hepatocytes. These results suggested that nuciferine exhibited a protective effect against high fructose-induced liver lipid accumulation through blocking MIB2-mediated CARD6 polyubiquitination and degradation.

Nuciferine Ameliorates Nonesterified Fatty Acid-Induced Bovine Mammary Epithelial Cell Lipid Accumulation, Apoptosis, and Impaired Migration via Activating LKB1/AMPK Signaling Pathway

High blood concentrations of nonesterified fatty acids (NEFAs) provoke various metabolic disorders and are associated with mammary tissue injury and decreased milk production in dairy cows. Nuciferine, an alkaloid found in Nelumbo nucifera leaves, has great potential for correcting lipid metabolism derangements and lipotoxicity. In this study, we evaluated the lipotoxicity induced by excessive NEFA in bovine mammary epithelial cells (bMECs) and investigated whether nuciferine alleviates NEFA-induced lipotoxicity and the underlying molecular mechanisms. We found that excessive NEFA (1.2 and 2.4 mM) induced lipid accumulation, apoptosis, and migration ability impairment in bMECs, whereas nuciferine could ameliorate these disarrangements, as indicated by decreasing triglyceride content, protein abundance of SREBP-1c, cytoplasmic cytochrome c, and cleaved caspase-3 and increasing protein abundance of PPARα and migration ability. Moreover, nuciferine could reverse NEFA-induced LKB1/AMPK signaling inhibition, and the protective effect of nuciferine on lipotoxicity caused by NEFA was abrogated by AMPK inhibitor dorsomorphin. Furthermore, transfection with LKB1 siRNA (si-LKB1) largely abolished the activation effect of nuciferine on AMPK. Overall, nuciferine can protect bMECs from excessive NEFA-induced lipid accumulation, apoptosis, and impaired migration by activating LKB1/AMPK signaling pathway.

Alkaloids as Promising Agents for the Management of Insulin Resistance: A Review

BACKGROUND

Insulin resistance is one of the main factors that lead to the development of type 2 diabetes mellitus (T2DM). The effect of alkaloids on insulin resistance has been extensively examined according to multiple scientific researches.

OBJECTIVE

In this work, we aimed to summarize the interesting results from preclinical and clinical studies that assessed the effects of natural alkaloids (berberine, nigelladine A, piperine, trigonelline, capsaicin, nuciferine, evodiamine, mahanine, and magnoflorine) on impaired insulin sensitivity and worsened insulin resistance, which play a pivotal role in the pathogenesis of type 2 diabetes.

METHODS

In the current review, PubMed, ScienceDirect, Springer, and Google Scholar databases were used. The inclusion criteria were based on the following keywords and phrases: insulin sensitivity, insulin resistance, alkaloids and insulin resistance, alkaloids and type 2 diabetes, mechanisms of action, and alkaloids.

RESULTS

The outcomes reported in this review demonstrated that the selected alkaloids increased insulin sensitivity and reduced insulin resistance in vitro and in vivo evidence, as well as in clinical trials, through improving insulin-signaling transduction mainly in hepatocytes, myocytes, and adipocytes, both at cellular and molecular levels. Insulin signaling components (InsR, IRS-1, PI3K, Akt, etc.), protein kinases and phosphatases, receptors, ion channels, cytokines, adipokines, and microRNAs, are influenced by alkaloids at transcriptional and translational levels, also in terms of function (activity and/or phosphorylation). Multiple perturbations associated with insulin resistance, such as ectopic lipid accumulation, inflammation, ER stress, oxidative stress, mitochondrial dysfunction, gut microbiota dysbiosis, and β-cell failure, are reversed after treatment with alkaloids. Furthermore, various indices and tests are employed to assess insulin resistance, including the Matsuda index, insulin sensitivity index (ISI), oral glucose tolerance test (OGTT), and insulin tolerance test (ITT), which are all enhanced by alkaloids. These improvements extend to fasting blood glucose, fasting insulin, and HbA1c levels as well. Additionally, the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and the Homeostasis Model Assessment of β-cell function (HOMA-β) are recognized as robust markers of insulin sensitivity and β-cell function, and it is noteworthy that alkaloids also lead to improvements in these two markers.

CONCLUSION

Based on the findings of the current review, alkaloids may serve as both preventive and curative agents for metabolic disorders, specifically type 2 diabetes. Nonetheless, there is an urgent need for additional clinical trials to explore the potential benefits of alkaloids in both healthy individuals and those with type 2 diabetes. Additionally, it is crucial to assess any possible side effects and interactions with antidiabetic drugs.

Study on the vasodilatory activity of lotus leaf extract and its representative substance nuciferine on thoracic aorta in rats

Lotus (Nelumbo nucifera) leaves are widely used for both edible and medicinal applications. For its further utilization, we studied the vasodilatory activity of lotus leaf extract for the first time. In this study, we obtained the extracts using different ratios of water and ethanol, which was followed by polarity-dependent extraction. We found that the CH₂Cl₂ layer exhibited better vasodilatory activity (EC₅₀ = 1.21 ± 0.10 μg/ml). HPLC and ESI-HRMS analysis of the CH₂Cl₂ layer using the standard product as a control revealed that nuciferine (E_max = 97.95 ± 0.76%, EC₅₀ = 0.36 ± 0.02 μM) was the main component in this layer. Further research revealed that nuciferine exerts a multi-target synergistic effect to promote vasodilation, via the NO signaling pathway, K⁺ channel, Ca²⁺ channel, intracellular Ca²⁺ release, α and β receptors, etc. Nuciferine exhibits good vasodilatory activity, and it exhibits the potential to be utilized as a lead compound.

Nuciferine Protects Against High-Fat Diet-Induced Hepatic Steatosis via Modulation of Gut Microbiota and Bile Acid Metabolism in Rats

Our previous study showed that nuciferine (NF) attenuated non-alcoholic fatty liver disease (NAFLD), which is attributed to a high-fat diet (HFD) through reinforcing intestinal barrier functions, regulating lipid metabolism, and improving inflammation. To clarify whether other mechanisms contribute to the anti-NAFLD efficacy of NF, the present study investigated the influence of NF on bile acid (BA) metabolism and gut microbiota in HFD-fed rats. The data demonstrated that NF changed the composition of colonic BA, particularly elevating conjugated BA and non-12OH BA levels. As shown by downregulated protein levels of FXR, FGF15, FGFR4, and ASBT and upregulated protein levels of CYP7A1 and CYP27A1, NF inhibited ileal FXR signaling, promoted BA synthesis, suppressed BA reabsorption, and facilitated fecal BA excretion. NF might affect hepatic FXR signaling, BA conjugation, and enterohepatic circulation by the changed mRNA levels of Fxr, Shp, Baat, Bacs, Bsep, Ntcp, Ibabp, and Ostα/β. Meanwhile, NF regulated the gut microbiota, characterized by decreased BSH-producing genus, 7α-dehydroxylation genus, and increased taurine metabolism-related genus. Spearman rank correlation analysis implied that Colidextribacter, Adlercreutzia, Family_XIII_AD3011_group, Lachnospiraceae_UCG-010, Eisenbergiella, and UCG-005 were robustly associated with particular BA monomers. In conclusion, our experiment results suggested that NF could exert a mitigating effect on NAFLD via regulating BA metabolism and modulating the gut microbiota.

Research Advances in Lotus Leaf as Chinese Dietary Herbal Medicine

Lotus leaf (Heye), the dry foliage of Nelumbo nucifera Gaertn, has been valuable as a dietary herbal medicine for thousands of years. Phytochemical studies indicated that alkaloids and flavonoids are the main components of Heye. Polysaccharides, terpenes, and amino acids are also active ingredients. The drug properties of Heye are mild and bitter. Meridian tropism is mainly distributed in the liver, spleen, and stomach meridian. In the Traditional Chinese medicine (TCM) theoretical system, it is in many formulas for the therapy of various symptoms, including wasting-thirst induced by summer heat, diarrhea caused by summer heat-dampness and spleen deficiency, hematochezia, flooding and spotting, among others. Nowadays, the extracts and active components of Heye demonstrate multiple bioactivities, for instance anti-obesity, anti-inflammatory, anti-oxidant, cardiovascular protective, anticancer, hepatoprotective, hypoglycemic, antiviral, antimicrobial, as well as hemostatic activities. This review will provide an overview of Heye serving as a typical plant with functions of both medicine and food, including its practical applications in terms of TCM and healthy diet, phytochemistry, pharmacological activity, together with its toxicity. Besides, the new points and prospects of Heye in the overview are also outlined straightforwardly.

The anticardiac fibrosis of total alkaloids of Plumula nelumbinis by regulating circulating lipidomic profile: In vivo study

Plumula nelumbinis has great medicinal potential as a herbal tea and traditional drug in China. This study was aimed to evaluate the anticardiac fibrosis of the total alkaloids of P. nelumbinis (TAP). TAP at 50 mg/kg/day significantly ameliorated isoproterenol-induced cardiac fibrosis in mice (p < .05). The circulating lipidomics study revealed that TAP improved the lipid metabolism dysfunction in cardiac fibrosis. Meanwhile, TAP suppressed the lipid accumulation, decreased MDA level (p < .01) in heart, and increased FFA level (p < .01). Furthermore, integrating lipidomics, chemical profiles and pharmacology network analysis found that AMPK and PI3K/Akt signaling pathways were the potential targeted pathway by TAP to regulate lipid metabolism dysfunction including glycerophospholipid metabolism. Above all, TAP provided a potential anticardiac fibrosis effect partly through regulation of lipid profiles. PRACTICAL APPLICATIONS: The total alkaloids of Plumula nelumbinis (TAP) suppressed ISO-induced cardiac fibrosis in mice. Network pharmacology analysis and experiments revealed that TAP-regulated AMPK and PI3K/Akt signaling pathway to improve lipid metabolism disorder in cardiac fibrosis. This study provides evidence to the therapeutic potential of TAP in the treatment of ISO-induced cardiac fibrosis and could be a drug candidate for prevention and treatment of cardiac fibrosis.

Distinct AMPK-Mediated FAS/HSL Pathway Is Implicated in the Alleviating Effect of Nuciferine on Obesity and Hepatic Steatosis in HFD-Fed Mice

Nuciferine (Nuci), the main aporphine alkaloid component in lotus leaf, was reported to reduce lipid accumulation in vitro. Herein we investigated whether Nuci prevents obesity in high fat diet (HFD)-fed mice and the underlying mechanism in liver/HepG2 hepatocytes and epididymal white adipose tissue (eWAT) /adipocytes. Male C57BL/6J mice were fed with HFD supplemented with Nuci (0.10%) for 12 weeks. We found that Nuci significantly reduced body weight and fat mass, improved glycolipid profiles, and enhanced energy expenditure in HFD-fed mice. Nuci also ameliorated hepatic steatosis and decreased the size of adipocytes. Furthermore, Nuci remarkably promoted the phosphorylation of AMPK, suppressed lipogenesis (SREBP1, FAS, ACC), promoted lipolysis (HSL, ATGL), and increased the expressions of adipokines (FGF21, ZAG) in liver and eWAT. Besides, fatty acid oxidation in liver and thermogenesis in eWAT were also activated by Nuci. Similar results were further observed at cellular level, and these beneficial effects of Nuci in cells were abolished by an effective AMPK inhibitor compound C. In conclusion, Nuci supplementation prevented HFD-induced obesity, attenuated hepatic steatosis, and reduced lipid accumulation in liver/hepatocytes and eWAT/adipocytes through regulating AMPK-mediated FAS/HSL pathway. Our findings provide novel insight into the clinical application of Nuci in treating obesity and related complications.

Alkaloids from lotus (Nelumbo nucifera): recent advances in biosynthesis, pharmacokinetics, bioactivity, safety, and industrial applications

Different parts of lotus (Nelumbo nucifera Gaertn.) including the seeds, rhizomes, leaves, and flowers, are used for medicinal purposes with health promoting and illness preventing benefits. The presence of active chemicals such as alkaloids, phenolic acids, flavonoids, and terpenoids (particularly alkaloids) may account for this plant's pharmacological effects. In this review, we provide a comprehensive overview and summarize up-to-date research on the biosynthesis, pharmacokinetics, and bioactivity of lotus alkaloids as well as their safety. Moreover, the potential uses of lotus alkaloids in the food, pharmaceutical, and cosmetic sectors are explored. Current evidence shows that alkaloids, mainly consisting of aporphines, 1-benzylisoquinolines, and bisbenzylisoquinolines, are present in different parts of lotus. The bioavailability of these alkaloids is relatively low in vivo but can be enhanced by technological modification using nanoliposomes, liposomes, microcapsules, and emulsions. Available data highlights their therapeutic and preventive effects on obesity, diabetes, neurodegeneration, cancer, cardiovascular disease, etc. Additionally, industrial applications of lotus alkaloids include their use as food, medical, and cosmetic ingredients in tea, other beverages, and healthcare products; as lipid-lowering, anticancer, and antipsychotic drugs; and in facial masks, toothpastes, and shower gels. However, their clinical efficacy and safety remains unclear; hence, larger and longer human trials are needed to achieve their safe and effective use with minimal side effects.

Nuciferine, an active ingredient derived from lotus leaf, lights up the way for the potential treatment of obesity and obesity-related diseases

Obesity, is an increasingly global public health problem associated complications. However, the proven anti-obesity agents are inefficient with adverse side effects; hence attention is being paid to novel drugs from natural resources to manage obesity and obesity-related diseases. Nuciferine (NF) is a high-quality aporphine alkaloid present in lotus leaf. Unlike the chemical drugs, NF elicits anti-obesity, anti-dyslipidemia, anti-hyperglycemic, anti-hypouricemic, anti-inflammatory, and anti-tumor effects, and affinity to neural receptors, and protection against obesity-related diseases. The underlying mechanism of NF includes the regulation of targeted molecules and pathways related to metabolism, inflammation, and cancer and modulation of Ca²⁺ flux, gut microbiota, and ferroptosis. Besides, the clinical application, availability, pharmacokinetics, pharmaceutics, and security of NF have been established, highlighting the potential of developing NF as an anti-obesity agent. Therefore, this review provides a comprehensive summarization, which sheds light on future research in NF.

Natural Aporphine Alkaloids with Potential to Impact Metabolic Syndrome

The incidence and prevalence of metabolic syndrome has steadily increased worldwide. As a major risk factor for various diseases, metabolic syndrome has come into focus in recent years. Some natural aporphine alkaloids are very promising agents in the prevention and treatment of metabolic syndrome and its components because of their wide variety of biological activities. These natural aporphine alkaloids have protective effects on the different risk factors characterizing metabolic syndrome. In this review, we highlight the activities of bioactive aporphine alkaloids: thaliporphine, boldine, nuciferine, pronuciferine, roemerine, dicentrine, magnoflorine, anonaine, apomorphine, glaucine, predicentrine, isolaureline, xylopine, methylbulbocapnine, and crebanine. We particularly focused on their impact on metabolic syndrome and its components, including insulin resistance and type 2 diabetes mellitus, endothelial dysfunction, hypertension and cardiovascular disease, hyperlipidemia and obesity, non-alcoholic fatty liver disease, hyperuricemia and kidney damage, erectile dysfunction, central nervous system-related disorder, and intestinal microbiota dysbiosis. We also discussed the potential mechanisms of actions by aporphine alkaloids in metabolic syndrome.

Discovery of eight alkaloids with D1 and D2 antagonist activity in leaves of Nelumbo nucifera Gaertn. Using FLIPR assays

ETHNOPHARMACOLOGICAL RELEVANCE

Dopamine receptors are long-standing primary targets in the treatment of mental diseases and there is growing evidence that suggests relationships between obesity and the dopamine system, especially dopamine D1 and D2 receptors. Leaves of Nelumbo nucifera Gaertn. (lotus leaves) have been medically used for helping long-term maintenance of weight loss. Whether and how components of lotus leaves function through the dopamine receptors remains unclear.

AIM OF THE STUDY

This work aimed to discover dopamine receptor-active alkaloids isolated from the lotus leaves, to evaluate their potencies and to analyze their structure activity relationship.

MATERIALS AND METHODS

Dried lotus leaves were prepared and total extract was divided into alkaloids and flavones. Eight alkaloids were separated and characterized by a combination of high-performance liquid chromatography, quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance, and assayed by a fluorometric imaging plate reader platform. Human embryonic kidney 239 cell lines expressing dopamine D1, D2 and serotonin 2A (5-HT2A) receptors, respectively, were cultured and used in the assay.

RESULTS

Alkaloids in the lotus leaves were the bioactive phytochemicals and inhibited dopamine from accessing the D1 and D2 receptors. All eight compounds functioned as D1-receptor antagonists and except N-nornuciferine, seven alkaloids functioned as D2-receptor antagonists. (S)-coclaurine and (R)-coclaurine are optical isomers and antagonized both D1 and D2 with equivalent potencies, suggesting that the optical rotation of the methylene linker in the monobenzyl isoquinoline backbone did not influence their activity. Among the eight alkaloids, O-nornuciferine was the potent antagonist to both receptors (the lowest IC₅₀ values, D1: 2.09 ± 0.65 μM and D2: 1.14 ± 0.10 μM) while N-nornuciferine was found to be the least potent as it moderately antagonized D1 and was inactive on D2. O-nornuciferine was also a 5-HT2A antagonist (IC₅₀~20 μM) while N-nornuciferine had no activity. These hinted the importance of a methyl group attached to the nitrogen atom in the aporphine backbone. Armepavine showed a nearly 10-fold selectivity to D2.

CONCLUSIONS

In this work, eight alkaloids were isolated from the leaves of Nelumbo nucifera Gaertn. and assayed on the D1 and D2 receptors. They were D1/D2 antagonists with IC₅₀ values in the mid- to low-micromolar range and O-nornuciferine was the most potent alkaloid among the eight. This family of alkaloids was biochemically evaluated on the dopamine receptors by the same platform for the first time.

Bilobalide: A review of its pharmacology, pharmacokinetics, toxicity, and safety

Bilobalide is a natural sesquiterpene trilactone from Ginkgo biloba leaves. It has good water solubility and is widely used in food and pharmaceutical fields. In the last decade, a plethora of studies on the pharmacological activities of bilobalide has been conducted and demonstrated that bilobalide possessed an extensive range of pharmacological activities such as neuroprotective, antioxidative, antiinflammatory, anti-ischemic, and cardiovascular protective activities. Pharmacokinetic studies indicated that bilobalide may have the characteristics of rapid absorption, good bioavailability, wide distribution, and slow elimination. This review aims to summarize the advances in pharmacological, pharmacokinetics, toxicity, and safety studies of bilobalide in the last decade with an emphasis on its neuroprotective and antiinflammatory activities, to provide researchers with the latest information and point out the limitations of relevant research at the current stage and the aspects that should be strengthened in future research.

Nuciferine Inhibited the Differentiation and Lipid Accumulation of 3T3-L1 Preadipocytes by Regulating the Expression of Lipogenic Genes and Adipokines

Purposes: Nuciferine, a main aporphine alkaloid component found in lotus leaf (Nelumbo nucifera), has been demonstrated to possess the property of reducing fat mass and alleviating dyslipidemia in vivo. The purpose of this study is to explore the effects of nuciferine on the proliferation and differentiation of 3T3-L1 cells and further investigate the possible underlying molecular mechanisms.

Methods: 3T3-L1 preadipocytes were treated with 0∼20 μM nuciferine for 24∼120 h, the cell viability was assessed using CCK8. 3T3-L1 preadipocytes and human primary preadipocytes were then induced differentiation and the effects of nuciferine on the lipid metabolism in differentiating and fully differentiated adipocytes were observed by the methods of intracellular triglyceride (TG) assay, Oil Red O staining, RT-qPCR and western blot. Transient transfection and dual luciferase reporter gene methods were used to assess the effects of nuciferine on FAS promoter activities.

Results: Nuciferine inhibited the proliferation of 3T3-L1 preadipocytes in a dose- and time-dependent manner. 20 μM nuciferine significantly attenuated lipid accumulation and reduced intracellular TG contents by 47.2, 59.9 and 55.4% on the third, sixth and ninth day of preadipocytes differentiation, respectively (all p < 0.05). Moreover, the mRNA levels of PPARγ, C/EBPα, C/EBPβ, FAS, ACC, HSL and ATGL were notably decreased by 39.2∼92.5% in differentiating preadipocytes when treated with 5∼20 μM nuciferine (all p < 0.05). In fully differentiated adipocytes treated with 20 μM nuciferine for 48 h, the mRNA levels of FAS, ACC and SREBP1 were remarkably downregulated by 22.6∼45.2% compared with the controls (0 μM) (all p < 0.05), whereas the expression of adipokines FGF21 and ZAG were notably promoted by nuciferine. Similarly, in fully differentiated human primary adipocytes, the mRNA levels of FAS, ACC, SREBP1 were decreased and the expression of FGF21 and ZAG were elevated after treated with nuciferine (all p < 0.05). Further mechanism studies showed that 2.5∼20 μM nuciferine significantly decreased FAS promoter activities in 3T3-L1 preadipocytes.

Conclusion: Nuciferine inhibited the proliferation and differentiation of 3T3-L1 preadipocytes. The inhibitory effects of nuciferine on adipogenesis might be due to the downregulation of PPARγ, C/EBPα and C/EBPβ, which led to the reduction of intracellular lipid accumulation in 3T3-L1 cells and by downregulating the expression of critical lipogenic enzymes, especially of FAS, which was achieved by inhibiting the FAS promoter activities. Besides, nuciferine promoted the expression of adipokines in fully differentiated adipocytes.

Plumula Nelumbinis: A review of traditional uses, phytochemistry, pharmacology, pharmacokinetics and safety

ETHNOPHARMACOLOGICAL RELEVANCE

Plumula Nelumbinis, the green embryo of the mature seeds of Nelumbo nucifera Gaertn, has a medical history of over 400 years. It is widely used for clearing the heart and heat, calming the mind, and promoting astringent essence and hemostasis in traditional Chinese medicine. Moreover, it usually dual use as food and medicine. This review aimed to evaluate the therapeutic potential of Plumula Nelumbinis by summarizing its botany, traditional uses, phytochemistry, pharmacology, pharmacokinetics and safety.

METHODS

This review summarized published studies on Plumula Nelumbinis in the Chinese Pharmacopoeia and literature databases including PubMed, Web of Science, Baidu Scholar, Wiley and China Knowledge Resource Integrated Database (CNKI), and limits the different research articles in botany, traditional uses, phytochemistry, pharmacology, pharmacokinetics and safety about Plumula Nelumbinis.

RESULTS

Plumula Nelumbinis is used to treat hypertension, arrhythmia, severe aplastic anemia, insomnia, encephalopathy and gynecological disease in traditional Chinese medicine and clinical studies. More than 130 chemicals have been isolated and identified from Plumula Nelumbinis, including alkaloids, flavonoids, polysaccharides and volatile oil. In addition, pharmacological effects, such as protective effects against cardiovascular diseases, neurological diseases, lung and kidney injury, anti-inflammatory and anticancer activities, were also evaluated by in vitro and in vivo studies. Moreover, the potential signaling pathways regulated by Plumula Nelumbinis in cardiovascular and neurological diseases and perspectives on Plumula Nelumbinis research were discussed.

CONCLUSION

Plumula Nelumbinis, a commonly used Chinese medicine, has a variety of traditional and modern therapeutic uses. Some traditional uses, especially the treatment of cardiovascular and neurological diseases, have been verified by pharmacological investigation. However, the pharmacological molecular mechanisms, pharmacokinetics and toxicology of Plumula Nelumbinis are still incomplete. In the future, a series of systematic studies on active compounds identification, pharmacological mechanism clarification, quality and safety evaluation are necessary.

Skip participates in formation and lipid metabolism of beige adipose and might mediate the effects of SIRT1 activator BTM-0512 on beige remodeling

Dissipating energy by activating thermogenic adipose to combating obesity attracts many interests. Ski-interacting protein (Skip) has been known to play an important role in cell proliferation and differentiation, but whether it participates in energy metabolism is not known. Our previous study revealed that BTM-0512 could induce beige adipose formation, accompanying with up-regulation of Skip, but the role of Skip in metabolism was unknown. In this study, we mainly investigated whether Skip was involved in beige remodeling of subcutaneous white preadipocytes as well as in lipid metabolism of differentiated beige adipocytes. The results showed that in high fat diet-induced obesity mice, the protein levels of Skip in subcutaneous and visceral white adipose as well as in brown adipose were all down-regulated, especially in subcutaneous white adipose. Then we cultured subcutaneous adipose derived-stem cells (ADSCs) and found knock-down of Skip (siSkip) inhibited the expressions of thermogenic adipose specific genes including PRDM16 and UCP1 in both undifferentiated ADSCs and differentiated beige adipocytes, which could abolish the effects of BTM-0512 on beige remodeling. We further observed that siSkip affected multiple rate-limiting enzymes in lipid metabolism. The expressions of ACC, GPAT-1, HSL and ATGL were down-regulated, while CPT1α expression was up-regulated by siSkip. The expression of AMPK was also decreased by siSkip. In conclusion, our study demonstrated that Skip might play an important role in the beige remodeling of white adipocytes as well as lipid metabolism of beige adipose.

The Establishment of an Efficient Callus Induction System for Lotus (Nelumbo nucifera)

The lotus (Nelumbo nucifera) is one of the most popular aquatic plants in Asia, and has emerged as a novel model for studying flower and rhizome development, and primary and secondary metabolite accumulation. Here, we developed a highly efficient callus induction system for the lotus by optimizing a series of key factors that affect callus formation. The highest efficient callus production was induced on immature cotyledon and embryo explants grown on Murashige and Skoog (MS) basal medium containing an optimized combination of 3 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L 6-benzylaminopurine (6-BA). In addition, lotus callus induction was proven to be influenced by lotus genotypes, light conditions, the developmental stages of explants and the time of explant sampling. Collecting immature cotyledons from seeds of the genotype “Shilihe 1”, at 9 days post pollination, and to culture the explants in darkness, are proposed as the optimum conditions for lotus callus induction. Interestingly, highly efficient callus induction was also observed in explants of immature embryo derived aseptic seedlings; and a small amount of lotus benzylisoquinoline alkaloid (BIA) and obvious expression of BIA biosynthetic genes were detected in lotus callus.

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.

Simultaneous Determination of Five Alkaloids by HPLC-MS/MS Combined With Micro-SPE in Rat Plasma and Its Application to Pharmacokinetics After Oral Administration of Lotus Leaf Extract

An environment-friendly and efficient method for simultaneous determination of five alkaloids (nunciferine, O-nornuciferin, liriodenine, armepavine, and pronuciferine) in rat plasma was established by HPLC-MS/MS associated with micro-solid phase extraction (micro-SPE). The plasma sample was pretreated by using micro-SPE columns filled with polymer materials PEP-2 and eluted by little organic solvent (400 µl acetonitrile). The five alkaloids were separated with acetonitrile and 0.1% formic acid aqueous solution on Eclipse plus C₁₈ column. The mode of positive electrospray ionization was used to measure the analytes in multiple-reaction monitoring (MRM). The determination coefficients (R²) of the five alkaloids were greater than 0.99. The lower limit of quantification (LLOQ) of O-nornuciferin, liriodenine, and armepavine was 0.5 ng·ml⁻¹, and that of nunciferine and pronuciferine was 1 ng·ml⁻¹. The validated method was effectively used for the pharmacokinetics of the five orally administrated alkaloids of lotus leaf extract in rat plasma.

Bilobalide Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

Bilobalide, the only sesquiterpene compound from Ginkgo biloba leaf, exhibits various beneficial pharmaceutical activities, such as antioxidant, anti-inflammation, and protective effects for the central nervous system. Several bioactive components extracted from Ginkgo biloba extract reportedly have the potential to attenuate lipid metabolism. However, the effect of bilobalide on lipid metabolism remains unclear. In this study, we used 3T3-L1 cells as the cell model to investigate the effect of bilobalide on adipogenesis. The results showed that bilobalide inhibited 3T3-L1 preadipocyte differentiation and intracellular lipid accumulation. Quantitative real-time PCR and western blotting results indicated that several specific adipogenic transcription factors and a few important adipogenesis-related genes were significantly down regulated on both mRNA and protein levels in bilobalide treatment groups. By contrast, the expression of some lipolytic genes, such as adipose triglyceride lipase, hormone-sensitive lipase (HSL), and carnitine palmitoyltransferase-1α, were all up-regulated by bilobalide treatment, and the phosphorylation of AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase 1, and HSL were stimulated. Furthermore, bilobalide treatment partially restored AMPK activity following its blockade by compound C (dorsomorphin). These results suggested that bilobalide inhibited adipogenesis and promoted lipolysis in 3T3-L1 cells by activating the AMPK signaling pathway.

Arctigenin improves lipid metabolism by regulating AMP-activated protein kinase and downstream signaling pathways

Although it has been reported that arctigenin (ARG) can reduce the body weight and inhibit adipogenic differentiation by activating AMP-activated protein kinase (AMPK), the exact signals responsible for the ARG-mediated antiobesity mechanism through AMPK are not well understood. In this study, we investigated the potential improvement of AGR on lipid metabolism using a high-fat diet (HFD)-induced hyperlipidemia rats and 3T3-L1 mature adipocytes. The levels of AMPK and its downstream factors were examined by Western blot analysis and real-time fluorescent quantitative polymerase chain reaction. We observed that ARG lowered the HFD-induced body weight and the levels of serum lipid. Moreover, ARG clearly alleviated fat deposition in the liver and reduced epididymal fat accumulation. ARG also suppressed lipogenesis and lipolysis but promoted fatty acid β-oxidation in adipocytes. Most importantly, ARG increased the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) and upregulated the messenger RNA levels of downstream genes related to fatty acid β-oxidation, such as carnitine palmitoyltransferase 1 and acyl-CoA oxidase 1 but downregulated the expression of peroxisome proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding transcription factor 1 (SREBP1c) and their targets, including lipogenesis-related genes such as CCAAT/enhancer-binding protein α, lipoprotein lipase, adipocyte protein 2, and fatty acid synthase (FAS), as well as lipolysis-related genes such as adipose triglyceride lipase and hormone-sensitive lipase. The activity of FAS was also decreased by ARG. We conclude that AMPK activation is important for the pharmacological effects of ARG. ARG may improve lipid metabolism by regulating the AMPK-ACC and AMPK-PPARγ/SREBP1c signaling pathways.

Benzylisoquinoline Alkaloids Biosynthesis in Sacred Lotus

Sacred lotus (Nelumbo nucifera Gaertn.) is an ancient aquatic plant used throughout Asia for its nutritional and medicinal properties. Benzylisoquinoline alkaloids (BIAs), mostly within the aporphine and bisbenzylisoquinoline structural categories, are among the main bioactive constituents in the plant. The alkaloids of sacred lotus exhibit promising anti-cancer, anti-arrhythmic, anti-HIV, and anti-malarial properties. Despite their pharmacological significance, BIA metabolism in this non-model plant has not been extensively investigated. In this review, we examine the diversity of BIAs in sacred lotus, with an emphasis on the distinctive stereochemistry of alkaloids found in this species. Additionally, we discuss our current understanding of the biosynthetic genes and enzymes involved in the formation of 1-benzylisoquinoline, aporphine, and bisbenzylisoquinoline alkaloids in the plant. We conclude that a comprehensive functional characterization of alkaloid biosynthetic enzymes using both in vitro and in vivo methods is required to advance our limited knowledge of BIA metabolism in the sacred lotus.

Nuciferine Inhibits Proinflammatory Cytokines via the PPARs in LPS-Induced RAW264.7 Cells

Inflammation is important and has been found to be an underlying cause in many acute and chronic human diseases. Nuciferine, a natural alkaloid containing an aromatic ring, is found in the nelumbo nucifera leaves. It has been shown to have potential anti-inflammatory activities, but the molecular mechanism has remained unclear. In this study, we found that nuciferine (10 μM) significantly inhibited the lipopolysaccharide (LPS)-induced inflammatory cytokine IL-6 and TNF-α production in RAW 264.7 cells. In addition, the luciferase reporter assay results of different subtypes of the peroxisome proliferator-activated receptor (PPAR) showed that nuciferine dose-dependently activated all the PPAR activities. Specific inhibitors of PPARα and PPARγ significantly abolished the production of inflammatory cytokines as well as IκBα degradation. However, PPARδ inhibitor did not show this effect. Our results suggested a potential molecular mechanism of the anti-inflammatory effects of nuciferine in LPS-induced inflammation, at least in part, by activating PPARα and PPARγ in RAW 264.7 cells.

Preventive Effect of Flavonol Derivatives Abundant Sanglan Tea on Long-Term High-Fat-Diet-Induced Obesity Complications in C57BL/6 Mice

Sanglan Tea (SLT) is a Chinese medicine-based formulation that is consumed as a health drink for the effective management of obesity-associated complications. However, its chemical components and mechanism of action in the prevention of hepatic steatosis and obesity-related impairments have been uncertain. In this study, we aimed to unveil the chemical profile of SLT and to explore its preventive mechanism in high-fat-diet-induced non-alcoholic fatty liver disease (NAFLD) and obesity-related consequences in C57BL/6 mice. Ultrahigh-performance liquid chromatography (UHPLC) coupled to a quadrupole-orbitrap high-resolution mass spectrometry (MS) analysis of SLT indicated that analogs of quercetin and kaempferol are major compounds of flavonoids in SLT. A dietary supplement of SLT efficiently managed the blood glucose elevation, retained the serum total cholesterol (TC), LDL-cholesterol (LDL-C), and triglyceride (TG) levels, as well as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity, and reduced the fat storage in the liver induced by a high-fat diet. The underlying mechanism of this preventive effect is hypothesized to be related to the inhibition of over-expression of lipogenesis and adipogenesis-related genes. Overall, this study suggests that SLT, being rich in quercetin and kaempferol analogs, could be a potential food supplement for the prevention of high-fat-diet-induced NAFLD and obesity-related complications.

Nuciferine inhibits LPS-induced inflammatory response in BV2 cells by activating PPAR-γ

Nuciferine, a bioactive component extracted from the lotus leaf, has been reported to have various anti-inflammatory effects. In the present study, we aimed to investigate the anti-inflammatory effects and mechanism of nuciferine on lipopolysaccharide (LPS)-stimulated BV2 microglia cells. The anti-inflammatory activity of nuciferine was measured by ELISA to detect the inflammatory mrdiators secretion in LPS-simulated BV2 microglia cells. The results demonstrated that nuciferine significantly inhibited LPS-induced TNF-α, IL-1β, PGE₂ and NO secretion. LPS-induced NF-κB activation was also suppressed by nuciferine. Further studies showed that nuciferine increased the expression of PPAR-γ. Functional aspects were analyzed using PPAR-γ specific inhibitor GW9662, which attenuated the LPS-induced secretion of proinflammatory mediators, such as TNF-α, IL-1β, PGE₂, and NO. In conclusion, these results suggested that nuciferine activated PPAR-γ, which subsequently inhibited LPS-induced inflammation in BV2 cells.

Nelumbo nucifera leaf extract treatment attenuated preneoplastic lesions and oxidative stress in the livers of diethylnitrosamine-treated rats

Lotus (Nelumbo nucifera Gaertn) possesses antioxidant, hepatoprotective, and anticancer potential. This study determined the protective role of aqueous extract from Nelumbo nucifera leaves (NLE) against N-diethylnitrosamine (DEN)-induced oxidative stress and hepatocellular carcinogenesis in a sample of Sprague-Dawley rats. NLE was fed orally to rats in which hepatic carcinoma was induced with DEN for 12 weeks. Five groups of 12 rats each were used for the study: Group I (control group) rats received distilled water; Group II rats were induced with DEN; Group III rats were induced with DEN and cotreated with 0.5% NLE; Group IV rats were induced with DEN and cotreated with 1.0% NLE; and Group V rats were induced with DEN and cotreated with 2.0% NLE. Clinical chemistry, organ weight, inflammatory marker, protein expression, enzyme, and antioxidant analyses were conducted. NLE administration to rats resulted in significantly decreased levels of serum alanine aminotransferase, aspartate aminotransferase, and albumin, which is indicative of hepatocellular damage, compared with the control group. DEN-induced oxidative stress was inhibited by NLE and this inhibition was paralleled by decreased lipid peroxides and increased glutathione transferase, superoxide dismutase, catalase, and glutathione peroxidase activity in liver tissues. The status of nonenzymatic antioxidants, such as reduced glutathione, was also found to be increased in NLE-administered rats. Furthermore, NLE decreased tumor size, hepatic Rac1, PKCα, and GSTπ expressions compared with the DEN-only group. Thus, supplementation of NLE reduced the adverse changes that occur because of liver cancer. These results prove that NLE protects against liver carcinogenesis induced because of treatment with DEN through blocking lipid peroxidation, hepatic cell damage, and enhancing the antioxidant defense system.

Lotus Leaf Aqueous Extract Reduces Visceral Fat Mass and Ameliorates Insulin Resistance in HFD-Induced Obese Rats by Regulating PPARγ2 Expression

Objectives: Lotus leaf is a kind of traditional Chinese medicine. We aimed to explore the effects of lotus leaf aqueous extract (LLAE) on peroxisome proliferative activated receptor γ2 (PPARγ2) expression in preadipocytes and adipocytes and further investigate its effects on high fat diet (HFD)-induced obese rats.

Methods: pGL3-Enhancer-PPARγ2 (625 bp)-Luc plasmid, a luciferase reporter gene expression plasmid containing PPARγ2 promoter, was stably transfected into 3T3-L1 preadipocytes. PPARγ2 promoter activities were determined by assaying the luciferase activities. Then PPARγ2 promoter activities in preadipocytes and PPARγ2 mRNA levels in human subcutaneous adipocytes were measured after the administration with LLAE. Additionally, the effects of LLAE on body weight, fat mass, glucose and lipid metabolism and the expression of PPARγ2, insulin receptor substrate 1 and glucose transporter 4 (GLUT4) in visceral adipose tissue (VAT) were measured in HFD-induced obese rats treated with low or high dose [0.5 or 3.0 g crude drug/(kg.d)] LLAE for 6 weeks.

Results: Ten μg/ml LLAE significantly increased the luciferase activities in 3T3-L1 cells and the stimulatory action reached 2.51 folds of controls when LLAE was 1000 μg/ml (P < 0.01). After treating 3T3-L1 cells with 100 μg/ml LLAE, the stimulatory role peaked at 32 h where it was 2.58 folds of controls (P < 0.01). Besides, 100 μg/ml LLAE significantly increased PPARγ2 mRNA levels in human adipocytes to 1.91 folds of controls (P < 0.01). In HFD-induced obese rats, administration with both low and high dose LLAE notably reduced visceral fat mass by 45.5 and 58.4%, respectively, and significantly decreased fasting serum insulin levels (P < 0.05). The high dose LLAE also significantly decreased homeostasis model assessment of insulin resistance in obese rats (P < 0.05). Furthermore, the mRNA levels of PPARγ2 and GLUT4 in VAT of obese rats were significantly increased when compared with control rats, and were notably suppressed by LLAE intervention for 6 weeks (P < 0.05).

Conclusion: LLAE significantly reduces visceral fat mass and ameliorates insulin resistance in HFD-induced obese rats. These beneficial effects of LLAE may associate with its role in stimulating PPARγ2 expression in preadipocytes and subcutaneous adipocytes and suppressing PPARγ2 and GLUT4 expression in VAT.

Nelumbo nucifera leaves extracts inhibit mouse airway smooth muscle contraction

Background

Alkaloids extracted from lotus leaves (AELL) can relax vascular smooth muscle. However, whether AELL has a similar relaxant role on airway smooth muscle (ASM) remains unknown. This study aimed to explore the relaxant property of AELL on ASM and the underlying mechanism.

Methods

Alkaloids were extracted from dried lotus leaves using the high temperature rotary evaporation extraction method. The effects of AELL on mouse ASM tension were studied using force measuring and patch-clamp techniques.

Results

It was found that AELL inhibited the high K⁺ or acetylcholine chloride (ACh)-induced precontraction of mouse tracheal rings by 64.8 ± 2.9%, or 48.8 ± 4.7%, respectively. The inhibition was statistically significant and performed in a dose-dependent manner. Furthermore, AELL-induced smooth muscle relaxation was partially mediated by blocking voltage-dependent Ca²⁺ channels (VDCC) and non-selective cation channels (NSCC).

Conclusion

AELL, which plays a relaxant role in ASM, might be a new complementary treatment to treat abnormal contractions of the trachea and asthma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1674-7) contains supplementary material, which is available to authorized users.

Target molecules in 3T3-L1 adipocytes differentiation are regulated by maslinic acid, a natural triterpene from Olea europaea

BACKGROUND

Metabolic syndrome is a set of pathologies among which stand out the obesity, which is related to the lipid droplet accumulation and changes to cellular morphology regulated by several molecules and transcription factors. Maslinic acid (MA) is a natural product with demonstrated pharmacological functions including anti-inflammation, anti-tumor and anti-oxidation, among others.

PURPOSE

Here we report the effects of MA on the adipogenesis process in 3T3-L1 cells.

METHODS

Cell viability, glucose uptake, cytoplasmic triglyceride droplets, triglycerides quantification, gene transcription factors such as peroxisome proliferator-activated receptor γ (PPARγ) and adipocyte fatty acid-binding protein (aP2) and intracellular Ca²⁺ levels were determined in pre-adipocytes and adipocytes of 3T3-L1 cells.

RESULTS

MA increased glucose uptake. MA also decreased lipid droplets and triglyceride levels, which is in concordance with the down-regulation of PPARγ and aP2. Finally, MA increased the intracellular Ca²⁺ concentration, which could also be involved in the demonstrated antiadipogenic effect of this triterpene.

CONCLUSION

MA has been demonstrated as potential antiadipogenic compound in 3T3-L1 cells.

Evolutionary origin of the NCSI gene subfamily encoding norcoclaurine synthase is associated with the biosynthesis of benzylisoquinoline alkaloids in plants

Sacred lotus is rich in biologically active compounds, particularly benzylisoquinoline alkaloids (BIAs). Here, we report on isolation of genes encoding (S)-norcoclaurine synthase (NCS) in sacred lotus, which is a key entry-enzyme in BIA biosynthesis. Seven NCS genes, designated NnNCS1 through NnNCS7, were identified in the sacred lotus genome, and five are located next to each other within a 83 kb region on scaffold 8. The NCS genes are divided into two subfamilies, designated NCSI and NCSII. The NCSII genes are universal in plants, while the NCSI genes are only identified in a limited number of dicotyledonous taxa that produce BIAs. In sacred lotus, only NnNCS4 belongs to the NCSII subfamily, whilst the rest NCS genes within the NCSI subfamily. Overall, the NnNCS7 gene was predominantly expressed in all tested tissues, and its expression is significantly correlated with alkaloid content in leaf. In contrast, the NnNCS4 expression shows no significant correlation with alkaloid accumulation in leaf, and its lack of expression cannot inhibit alkaloid accumulation. Taken together, these results suggest that the NCSI subfamily is crucial for BIA biosynthesis, and its origin may represent an important evolutionary event that allows certain plant taxa to produce BIAs.

Analysis of Isoquinoline Alkaloid Composition and Wound-Induced Variation in Nelumbo Using HPLC-MS/MS

Alkaloids are the most relevant bioactive components in lotus, a traditional herb in Asia, but little is known about their qualitative and quantitative distributions. Here, we report on the alkaloid composition in various lotus organs. Lotus laminae and embryos are rich in isoquinoline alkaloids, whereas petioles and rhizomes contain trace amounts of alkaloids. Wide variation of alkaloid accumulation in lamina and embryo was observed among screened genotypes. In laminae, alkaloid accumulation increases during early developmental stages, reaches the highest level at full size stage, and then decreases slightly during senescence. Vegetative and embryogenic tissues accumulate mainly aporphine-type and bisbenzylisoquinoline-type alkaloids, respectively. Bisbenzylisoquinoline-type alkaloids may be synthesized mainly in lamina and then transported into embryo via latex through phloem translocation. In addition, mechanical wounding was shown to induce significant accumulation of specific alkaloids in lotus leaves.