The Structure Basis of Phytochemicals as Metabolic Signals for Combating Obesity

Microemulsion-based drug delivery system identifies pepper alkaloids as anti-obesity compounds

Obesity is a significant contributor to various metabolic diseases such as heart disease and diabetes. Due to the adverse effects of synthetic anti-obesity drugs, natural products from functional food plants, which mimic the effects of synthetic chemicals, present promising alternatives. However, many natural plant-derived compounds are poorly soluble in water, resulting in low bioavailability within the gastrointestinal tract, a key limitation for the effectiveness of many hydrophobic substances. In this study we developed a microemulsion-based drug delivery system in Drosophila, which effectively enhanced the solubility of hydrophobic compounds without noticeable effects on food intake or survival in fruit flies. This system consisted of cremophor EL, ethanol and ethyl oleate (7:6:1), which enabled the establishment of an emulsion-based liquid high-fat diet (LHFD) model, followed by a pilot screening of 161 standard substances from traditional Chinese medicine. We found that piperine (PIP), an alkaloid derived from black pepper, significantly decreased triacylglycerol (TAG) levels in both the intestine and in whole flies. We demonstrated that piperine (1 mg/ml) significantly elevated cytosolic Ca2+ levels in enterocytes by activating Transient receptor potential (TRP) channels. TRPV1 agonists such as capsaicin and evodiamine (another alkaloid identified during the screening) also exhibited anti-obesity effects. Increased Ca2+ levels resulted in the suppression of dietary lipase Magro expression through the activation of the transcription factor cAMP response element binding protein (CREB). Furthermore, hydrophobic compounds in the microemulsion were successfully delivered to distal tissues including liver and brain blood vessels in mice, and PIP in the microemulsion was sufficient to reduce body weight in mice. In conclusion, we have developed a microemulsion-based U-GLAD platform for drug delivery, and piperine is identified as a weight-controlling compound, providing a novel approach to the treatment of obesity and its associated symptoms.

Phytochemicals in Obesity Management: Mechanisms and Clinical Perspectives

PURPOSE OF REVIEW

This review explores the mechanistic pathways and clinical implications of phytochemicals in obesity management, addressing the global health crisis of obesity and the pressing need for effective, natural strategies to combat this epidemic.

RECENT FINDINGS

Phytochemicals demonstrate significant potential in obesity control through various molecular mechanisms. These include the modulation of adipogenesis, regulation of lipid metabolism, enhancement of energy expenditure, and suppression of appetite. Recent studies have provided compelling clinical evidence supporting the use of specific phytochemicals in obesity treatment. Notable among these are green tea extract, rich in catechins; garcinia cambogia, containing hydroxycitric acid; resveratrol, found in grapes and berries; and berberine, derived from various plants. These compounds have shown promising results in clinical trials, Recent studies show that phytochemicals contribute to weight loss, BMI reduction, and lipid profile improvement, highlighting their potential in managing obesity and associated comorbidities. However, research in this field also faces challenges, including inconsistent bioavailability and the need for standardized dosing protocols. Phytochemicals offer a promising avenue for obesity management, acting through multiple pathways to influence weight control. While clinical evidence supports the efficacy of certain phytochemicals, further research and rigorous clinical validation are necessary to fully understand their potential and overcome existing challenges. This review underscores the importance of continued investigation into phytochemicals as a complementary approach to addressing the global obesity epidemic, potentially leading to more effective and natural interventions for weight management.

Ellagic Acid Modulates Necroptosis, Autophagy, Inflammations, and Stress to Ameliorate Nonalcoholic Liver Fatty Disease in a Rat Model

Nonalcoholic fatty liver disease (NAFLD) is considered one of the most common metabolic disorders worldwide. Although the pathoetiology of NAFLD is not fully elucidated, recent evidence suggests the involvement of stress, inflammation, and programmed death in the onset and progression of the disease. This investigation aimed to evaluate the effects of ellagic acid (EA), a known herbal antioxidant, on a high-fat diet (HFD)-induced animal model of NAFLD by evaluating the status of lipid profile, necroptosis (RIPK1, RIPK3, and MLKL), autophagy (LC3, ATG5, and BECN1), inflammation (TNF-α, IL-6, IL-4, and IL-10), and stress (SOD, CAT, GR, GPx, and MDA). In this regard, rats were randomly divided into 6 groups as follows: normal diet controls, HFD (supplemented with high caloric diet model), EA low dose (HFD and 10 mg/kg/day EA), EA middle dose (HFD and 25 mg/kg/day EA), EA high dose (HFD and 50 mg/kg/day EA), and Rosiglitazone (HFD and 10 mg/kg/day Rosi). After the treatment, the levels of markers related to necroptosis and autophagy in the liver tissue as well as the lipid profiles, inflammation, and oxidative stress status were analyzed. It was shown that the dose of EA was able to improve the weight gain and lipid profile when compared to NAFLD animals (p-value < 0.001). Moreover, EA increased the level of LC3 and ATG5 while decreasing BECN 1, RIPK1, RIPK3, and MLKL compared to the HFD-induced NAFLD rats (p-value < 0.05). TNF-α and IL-6 were decreased after EA administration, whereas IL-4 and IL-10 levels were increased (p-value < 0.001). Furthermore, the increase in the activity of SOD, CAT, GR, and GPx along with the decrease in MDA levels indicated the suppression of oxidative stress by EA treatment compared to the NAFLD rats (p-value < 0.0001). The current findings may suggest that EA improves NAFLD via modulation of necroptosis, autophagy, inflammation, and stress.

Leptin pathway is a crucial target for anthocyanins to protect against metabolic syndrome

The high prevalence of metabolic syndrome is threatening the health of populations all over the world. Contemporary work demonstrates that high leptin concentration is directly related to the development of metabolic syndrome such as obesity, fatty liver diseases, type 2 diabetes mellitus and cardiovascular diseases. Anthocyanins are a widespread group of dietary polyphenols, which can ameliorate chronic diseases related to metabolic syndrome. In addition, anthocyanins can regulate the leptin pathway in chronic metabolic diseases, however the potential mechanism between anthocyanin and leptin is complex and elusive. In this review paper, we have evaluated the bioactivity of anthocyanins on the mediation of leptin level and the upstream and downstream pathways in chronic metabolic diseases. Anthocyanins could regulate the hypertrophy of adipose tissue, and the expression of leptin level via mediating TNF-α, C/EBP, PPAR, CREB and SREBP-1. Anthocyanins promoted the leptin sensitivity by increasing the level of leptin receptor, phosphorylation of JAK2/STAT3, PI3K/AKT, and additionally ameliorated metabolic disorder related outcome, including oxidative stress, inflammation, lipid accumulation, insulin resistance and the balance of gut microbiota. However, direct evidence of anthocyanins treatment on leptin signal transduction is still limited which calls for future molecular binding and gene regulation test.

New Insights for Polyphenolic Compounds as Naturally Inspired Proteasome Inhibitors

Polyphenols, an important class of natural products, are widely distributed in plant-based foods. These compounds are endowed with several biological activities and exert protective effects in various physiopathological contexts, including cancer. We herein investigated novel potential mechanisms of action of polyphenols, focusing on the proteasome, which has emerged as an attractive therapeutic target in cancers such as multiple myeloma. We carried out a structure-based virtual screening study using the DrugBank database as a repository of FDA-approved polyphenolic molecules. Starting from 86 polyphenolic compounds, based on the theoretical binding affinity and the interactions established with key residues of the chymotrypsin binding site, we selected 2 promising candidates, namely Hesperidin and Diosmin. The further assessment of the biologic activity highlighted, for the first time, the capability of these two molecules to inhibit the β5-proteasome activity and to exert anti-tumor activity against proteasome inhibitor-sensitive or resistant multiple myeloma cell lines.

Immunomodulation by cannabidiol in bovine primary ruminal epithelial cells

BACKGROUND

Ruminant livestock experience a number of challenges, including high concentrate diets, weaning and transport, which can increase their risk of disorders such as ruminal acidosis, and the associated inflammation of the ruminal epithelium. Cannabidiol (CBD), a phytochemical from hemp (Cannabis sativa), is a promising target as a therapy for gastrointestinal inflammation, and may be extremely valuable as either a treatment or prophylactic. However, the effects of CBD in the the ruminant gastrointestinal tract have not been explored, in part due to the restrictions on feeding hemp to livestock. Therefore, the objective of this study was to investigate the immunomodulatory properties of CBD using a model of inflammation in primary ruminal epithelial cells (REC). In addition, CBD dose was evaluated for possible cytotoxic effects.

RESULTS

Negative effects on cell viability were not observed when REC were exposed to 10 μM CBD. However, when the dose was increased to 50 μM for 24 h, there was a significant cytotoxic effect. When 10 μM CBD was added to culture media as treatment for inflammation induced with lipopolysaccharide (LPS), expression of genes encoding for pro-inflammatory cytokine IL1B was less compared to LPS exposure alone, and CBD resulted in a down-regulation of IL6. As a pre-treatment, prior to LPS exposure, REC had decreased expression of IL6 and CXCL10 while CBD was present in the media, but not when it was removed prior to addition of LPS.

CONCLUSIONS

Results suggest that CBD may reduce cytokine transcription both during LPS-induced inflammation and when used preventatively, although these effects were dependent on its continued presence in the culture media. Overall, these experiments provide evidence of an immunomodulatory effect by CBD during a pro-inflammatory response in primary REC in culture.

Association of Plant-Based and High-Protein Diets with a Lower Obesity Risk Defined by Fat Mass in Middle-Aged and Elderly Persons with a High Genetic Risk of Obesity

Obesity has become a severe public health challenge globally. The present study aimed to identify separate and interactive dietary, genetic, and other factors that increase the risk of obesity as measured by body fat (BF) mass. We utilized a genome-wide association study to identify genetic variants associated with high fat mass (obesity; n = 10,502) and combined them to generate polygenic risk scores (PRS) of genetic variants interacting with each other in adults aged over 40 while excluding body-fat-related diseases in a city-hospital-based cohort (n = 53,828). It was validated in Ansan/Ansung plus rural cohorts (n = 13,007). We then evaluated dietary and lifestyle factors in subjects to assess what factors might help overcome a genetic propensity for higher BF. The three-SNP model included brain-derived neurotrophic factor (BDNF)_rs6265, fat-mass- and obesity-associated protein (FTO)_rs1421085, and SEC16B_rs509325. The genes with the minor alleles of ADCY3_rs6545790 and BAIAP2_rs35867081 increased their gene expression in the visceral and subcutaneous adipocytes, but their gene expression decreased in the hypothalamus in eQTL analysis. In the three-SNP model, the PRS was associated with BF mass by 1.408 and 1.396 times after adjusting covariates 1 (age, gender, survey year, residence area, education, and income) and 2 (covariates in model 1 plus energy intake, alcohol intake, regular exercise, and smoking status), respectively. However, when separating subjects by PRS of the three-SNP model, a plant-based diet was the most significant factor associated with low BF, followed by high-protein diets and lower energy intakes. They could offset the effects of high genetic risk for high BF. In conclusion, modulating nutrient intakes might overcome a high genetic risk for obesity. Dietary choices favoring more plant-based and higher-protein foods might help prevent increased BF in Asians and potentially people of other ethnicities with high polygenetic risk scores.

A New Frontier in Studying Dietary Phytochemicals in Cancer and in Health: Metabolic and Epigenetic Reprogramming

Metabolic rewiring and epigenetic reprogramming are closely inter-related, and mutually regulate each other to control cell growth in cancer initiation, promotion, progression, and metastasis. Epigenetics plays a crucial role in regulating normal cellular functions as well as pathological conditions in many diseases, including cancer. Conversely, certain mitochondrial metabolites are considered as essential cofactors and regulators of epigenetic mechanisms. Furthermore, dysregulation of metabolism promotes tumor cell growth and reprograms the cells to produce metabolites and bioenergy needed to support cancer cell proliferation. Hence, metabolic reprogramming which alters the metabolites/epigenetic cofactors, would drive the epigenetic landscape, including DNA methylation and histone modification, that could lead to cancer initiation, promotion, and progression. Recognizing the diverse array of benefits of phytochemicals, they are gaining increasing interest in cancer interception and treatment. One of the significant mechanisms of cancer interception and treatment by phytochemicals is reprogramming of the key metabolic pathways and remodeling of cancer epigenetics. This review focuses on the metabolic remodeling and epigenetics reprogramming in cancer and investigates the potential mechanisms by which phytochemicals can mitigate cancer.