Supplementation with Vitis vinifera L. skin extract improves insulin resistance and prevents hepatic lipid accumulation and steatosis in high-fat diet-fed mice

A Systematic Review of the Beneficial Effects of Berry Extracts on Non-Alcoholic Fatty Liver Disease in Animal Models

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries and is strongly associated with several metabolic disorders. Plant-derived bioactive extracts, such as berry extracts, with high antioxidant capacity have been used for the treatment and prevention of this pathology. Moreover, they promote circular economy and sustainability.

OBJECTIVE

To study the beneficial effects of extracts from different parts of berry plants in animal models of NAFLD.

DATA SOURCES

A systematic research of the MEDLINE (via PubMed), Cochrane, and Scopus databases was conducted to identify relevant studies published after January 2011. In vivo animal studies of NAFLD were included in which berry extracts of different parts of the plant were administered and significantly improved altered biomarkers related to the pathology, such as lipid metabolism and hepatic steatosis, glucose and glycogen metabolism, and antioxidant and anti-inflammatory biomarkers.

DATA EXTRACTION

Of a total of 203 articles identified, 31 studies were included after implementation of the inclusion and exclusion criteria.

DATA ANALYSIS

Most of the studies showed a decrease in steatosis and a stimulation of genes related to β-oxidation and downregulation of lipogenic genes, with administration of berry extracts. Berry extracts also attenuated inflammation and oxidative stress.

CONCLUSIONS

Administration of berry extracts seems to have promising potential in the design of enriched foodstuffs or nutraceuticals for the treatment of NAFLD.

Exploring antioxidant potential of agricultural by-products: a systematic review

Background

Agricultural waste sourced from various activities that occur along the agricultural supply chain including post-harvest, processing, and consumption processes, can pose a threat to ecosystem balance and community welfare. Data shows that agricultural by-products have the potential to be utilized because they contain antioxidant compounds. This systematic review study aims to identify and assess the antioxidant activity of agricultural by-products through various extraction methods.

Methods

This systematic review collected literature in the last 10 years (2013-2023) from Google Scholar, Semantic, and Scopus-indexed articles with the help of Publish or Perish. Using the help of boolean operators (AND) and (OR) in searching using keywords. The steps applied adapt the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), including identification, screening, eligibility, and inclusion.

Results

Literature collection data shows that the dominant processing method used is the solvent extraction method to determine the antioxidant value of various agricultural waste by-products. Followed by microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) methods. A wide range of antioxidant activity values were found depending on the type of agricultural waste and processing technique. One potential utilization of agricultural wastes rich in antioxidant content is as additives in formulations in the cosmetic industry.

Conclusion

Agricultural waste by-products have high potential of antioxidant content, depending on the type of waste and extraction method. The dominant agricultural waste used is by-products from the fruit group. The utilization of agricultural waste that is rich in antioxidants has the potential to be utilized in the cosmetic industry.

A Mechanistic Review on Therapeutic Potential of Medicinal Plants and their Pharmacologically Active Molecules for Targeting Metabolic Syndrome

Metabolic syndrome (MetS) therapy with phytochemicals is an emerging field of study with therapeutic potential. Obesity, insulin resistance, high blood pressure, and abnormal lipid profiles are all components of metabolic syndrome, which is a major public health concern across the world. New research highlights the promise of phytochemicals found in foods, including fruits, vegetables, herbs, and spices, as a sustainable and innovative method of treating this illness. Anti-inflammatory, antioxidant, and insulin-sensitizing qualities are just a few of the many positive impacts shown by bioactive substances. Collectively, they alleviate the hallmark symptoms of metabolic syndrome by modulating critical metabolic pathways, boosting insulin sensitivity, decreasing oxidative stress, and calming chronic low-grade inflammation. In addition, phytochemicals provide a multimodal strategy by targeting not only adipose tissue but also the liver, skeletal muscle, and vascular endothelium, all of which have a role in the pathogenesis of MetS. Increasing evidence suggests that these natural chemicals may be useful in controlling metabolic syndrome as a complementary treatment to standard medication or lifestyle changes. This review article emphasizes the therapeutic potential of phytochemicals, illuminating their varied modes of action and their ability to alleviate the interconnected causes of metabolic syndrome. Phytochemical-based interventions show promise as a novel and sustainable approach to combating the rising global burden of metabolic syndrome, with the ultimate goal of bettering public health and quality of life.

Phenolic composition of grape pomace and its metabolism

Grape pomace is the most important residual after wine making, and it is considered to be a very abundant source for the extraction of a wide range of polyphenols. These polyphenols exhibit a variety of bioactivities, such as antioxidant, anti-inflammatory, and anti-cancer. They are also beneficial in alleviating metabolic syndrome and regulating intestinal flora, etc. These health effects are most likely contributed by polyphenol metabolite, which are formed by the grape pomace phenolics after a complex metabolic process in vivo. Therefore, understanding the phenolic composition of grape pomace and its metabolism is the basis for an in-depth study of the biological activity of grape pomace polyphenols. In this paper, we first summarize the composition of phenolics in grape pomace, then review the recent studies on the metabolism of grape pomace phenolics, including changes in phenolics in the gastrointestinal tract, their pharmacokinetics in the systemic circulation, the tissue distribution of phenolic metabolites, and the beneficial effects of metabolites on intestinal health, and finally summarize the effects of human health status and dietary fiber on the metabolism of grape polyphenols. It is expected to provide help for the in-depth research on the metabolism and biological activity of grape pomace polyphenol extracts, and to provide theoretical support for the development and utilization of grape pomace.

Grape exosome-like nanoparticles: A potential therapeutic strategy for vascular calcification

Vascular calcification (VC) is prevalent in hypertension, diabetes mellitus, chronic kidney disease, and aging and has been identified as an important predictor of adverse cardiovascular events. With the complicated mechanisms involved in VC, there is no effective therapy. Thus, a strategy for attenuating the development of VC is of clinical importance. Recent studies suggest that grape exosome-like nanoparticles (GENs) are involved in cell-cell communication as a means of regulating oxidative stress, inflammation, and apoptosis, which are known to modulate VC development. In this review, we discuss the roles of GENs and their potential mechanisms in the development of VC.

Dietary Flavonoids and Insulin Signaling in Diabetes and Obesity

Type 2 diabetes (T2D) and obesity are relevant worldwide chronic diseases. A common complication in both pathologies is the dysregulation of the insulin-signaling pathway that is crucial to maintain an accurate glucose homeostasis. Flavonoids are naturally occurring phenolic compounds abundant in fruits, vegetables and seeds. Rising evidence supports a role for the flavonoids against T2D and obesity, and at present, these compounds are considered as important potential chemopreventive agents. This review summarizes in vitro and in vivo studies providing data related to the effects of flavonoids and flavonoid-rich foods on the modulation of the insulin route during T2D and obesity. Notably, few human studies have evaluated the regulatory effect of these phenolic compounds at molecular level on the insulin pathway. In this context, it is also important to note that the mechanism of action for the flavonoids is not fully characterized and that a proper dosage to obtain a beneficial effect on health has not been defined yet. Further investigations will contribute to solve all these critical challenges and will enable the use of flavonoids to prevent, delay or support the treatment of T2D and obesity.

Ethno-pharmacological insulin signaling induction of aqueous extract of Syzygium paniculatum fruits in a high-fat diet induced hepatic insulin resistance

ETHNOPHARMACOLOGICAL RELEVANCE

The ethnopharmacological significance of the fruits of Syzygium paniculatum Gaertn (Magenta Cherry) is widely recognized in the Indian traditional medicine system to treat various disorders, such as diabetes, hyperlipidaemia, hypertension, and cardiovascular problems.

AIM OF THE STUDY

This research work investigated the supplementation of the aqueous extract of S. paniculatum fruit (AESPF) on liver function; the molecular effects on the expression of the protein of insulin receptor (IR) and insulin receptor substrate 1 (IRS-1) in high-fat diet-induced hepatic insulin resistance in the rat model.

MATERIALS AND METHODS

High-fat diet was used to induce obesity in albino Wistar for 120 days. Biochemical, enzymatic, and histopathological analysis, as well as analysis of hepatic insulin resistance proteins and expression of IRS-1, were performed.

RESULTS

The supplementation of AESPF with a dose of 100 mg/kg bw significantly reduced bodyweight, blood sugar, insulin, lipid profiles, and liver enzymes. Hepatic insulin resistance was improved with a reduced level of IR and IRS-1 to protein levels. HFD alters the sensitivity of hepatocytes to insulin due to the down-regulation of insulin receptor proteins.

CONCLUSIONS

The fruits of S. paniculatum possess biological activities to alleviate all risky effects by regulating hepatic lipogenesis activity that can be used in the progress of medication for HFD-induced hepatic insulin resistance and metabolic disorders.

Vitis labrusca Extract (HP01) Improves Blood Circulation and Lipid Metabolism in Hyperlipidemic Rats

Excessive intake of high-lipid foods and lifestyle changes can easily cause hyperlipidemia. Hyperlipidemia is clinically considered a major risk factor for cardiovascular disease, which is the second leading cause of death worldwide. In this study, the effects of a Vitis labrusca extract (HP01) on coagulation, platelet aggregation, and lipid metabolism were investigated in hyperlipidemic rats. A rat model of high-fat diet- (HFD-) induced hyperlipidemia was used. Hemostatic parameters and lipid levels were investigated after HP01 treatment of hyperlipidemic rats. Different doses of HP01 (200 mg/kg/day and 400 mg/kg/day, p.o.) were administered for 3 weeks, and prothrombin time (PT), activated partial thromboplastin time (aPTT), and platelet aggregation and bleed time (BT) were determined. The levels of thromboxane B(2) (TXB(2)) and serotonin were measured using enzyme-linked immunosorbent assay kits. Simultaneously, hepatic function and blood fat indexes, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), malondialdehyde (MDA), and glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were also measured. In comparison with the data obtained for rats in the untreated HFD group, HP01 (200 mg/kg) treatment prolonged PT but did not affect aPTT. HP01 treatment did not alter plasma TXB(2), PGI2, or serotonin levels. However, HP01 showed some effects in improving liver function by reducing the levels of hepatic lipids. ALT, MDA, and hepatic TG levels significantly decreased, whereas GSH, GPx, CAT, and SOD levels significantly increased. These results confirm the HP01 extract will improve thromboplastic and the liver metabolic disorders in hyperlipidemia by oxidative stress response.

Antioxidant Molecules from Plant Waste: Extraction Techniques and Biological Properties

The fruit, vegetable, legume, and cereal industries generate many wastes, representing an environmental pollution problem. However, these wastes are a rich source of antioxidant molecules such as terpenes, phenolic compounds, phytosterols, and bioactive peptides with potential applications mainly in the food and pharmaceutical industries, and they exhibit multiple biological properties including antidiabetic, anti-obesity, antihypertensive, anticancer, and antibacterial properties. The aforementioned has increased studies on the recovery of antioxidant compounds using green technologies to value plant waste, since they represent more efficient and sustainable processes. In this review, the main antioxidant molecules from plants are briefly described and the advantages and disadvantages of the use of conventional and green extraction technologies used for the recovery and optimization of the yield of antioxidant naturals are detailed; finally, recent studies on biological properties of antioxidant molecules extracted from plant waste are presented here.

Two polyphenol-rich Brazilian fruit extracts protect from diet-induced obesity and hepatic steatosis in mice

Consumption of polyphenol-rich food is associated with better metabolic health. Tucum-do-Pantanal (Bactris setosa Mart) and taruma-do-cerrado (Vitex cymosa Bertero ex Spreng) are underexploited native Brazilian fruits with an important source of phytochemicals. In this study, we assessed the effects of 100 mg kg-1 tucum (TPE) and taruma (TCE) extracts on diet-induced obesity (DIO) C57BL/6J mice. After 8 weeks of daily treatment, TPE and TCE were found to significantly prevented the diet-induced body weight gain and fully protected against hepatic steatosis associated with a tendency to stimulate hepatic AMPK phosphorylation. TPE reduced visceral obesity and improved glucose metabolism as revealed by an improvement of the insulin tolerance test, a reduction in the insulin fasting level, and a decreased glucose-induced hyperinsulinemia during an oral glucose tolerance test. TPE and TCE showed promising effects on the treatment of obesity and NAFLD, furthermore, TPE on insulin resistance.

Vitis vinifera L. Grape Skin Extract Prevents Development of Hypertension and Altered Lipid Profile in Spontaneously Hypertensive Rats: Role of Oxidative Stress

This study investigated the protective effect of a Vitis vinifera L. grape skin extract (ACH09) on blood pressure, lipid profile, and oxidative status in spontaneously hypertensive rats (SHR). Systolic blood pressure (SBP), total cholesterol, triglyceride, and glucose levels, as well as oxidative damage and antioxidant activity in the plasma and kidney, were evaluated in four experimental groups: control Wistar rats (W-C) and SHR-C that received water, and Wistar rats and SHR treated with ACH09 (200 mg/kg/d) in drinking water for 12 weeks (W-ACH09 and SHR-ACH09, respectively). SBP increased in the SHR group compared with the W groups and the treatment with ACH09 prevented the development of hypertension. Plasma triglyceride and total cholesterol levels increased in SHR compared with W-C rats; these changes prevented by treatment with ACH09. Glucose levels did not differ between the groups. The SHR group had increased oxidative damage in plasma, as expressed by 2-thiobarbituric acid reactive substances (TBARS) levels, and this prevented by ACH09. Levels of TBARS in the kidneys were lower in the SHR-ACH09 group than in the SHR-C group. Further, ACH09 increased the superoxide dismutase activity in both the plasma and kidneys of both SHR and Wistar rats. These results suggest that ACH09 is protective against disruption of blood pressures, oxidant status, and lipid profile in SHR, and provide important evidence on the benefits of ACH09 on hypertension and associated cardiovascular complications.

Effects of Polyphenol-Rich Fruit Extracts on Diet-Induced Obesity in Rodents: Systematic Review and Meta-Analysis

Background::

Obesity is a complex condition of high prevalence and cost to the public health system. Recent research has demonstrated the potential of natural products, such as polyphenol-rich fruit extracts, for use in the treatment of obesity. The goal of this systematic review and meta-analysis is to determine the metabolic effects of polyphenol-rich fruit extracts on diet-induced obesity (DIO) in rodents.

Methods:

We searched MEDLINE, EMBASE, and Web of Science databases to identify preclinical studies that assessed polyphenol-rich fruit extracts compared to placebo on DIO in rodents in December 2018. Two researchers selected the studies, extracted the data, and assessed the quality of studies. Meta-analyses of standardized mean difference (SMD) of outcomes were calculated in Stata 11, and causes of heterogeneity were assessed by meta-regression.

Results:

We included 14 studies in the systematic review and 13 studies with 21 matched groups in the metaanalysis. Polyphenol-rich fruit extracts reduced the total body weight gain (SMD = -1.48; confidence interval: - 1.95, -1.01), energy intake (SMD = -0.42; -0.67, -0.17), visceral adipose tissue (SMD = -0.96; -1.25, -0.66), triglycerides (SMD = -1.00; -1.39, -0.62), cholesterol (SMD = -1.18, -1.66, -0.69), LDL- c (SMD = -1.15; -1.65, - 0.65), fasting glucose (SMD = -1.05; -1.65, -0.46), and fasting insulin (SMD = -1.40; -1.80, -1.00) when compared to vehicle.

Conclusion:

Polyphenol-rich fruit extract had positive effects on weight gain, dyslipidaemia, insulin resistance at different doses, and fruit source in male mice.

Mitophagy in Hepatic Insulin Resistance: Therapeutic Potential and Concerns

Metabolic syndrome, characterized by central obesity, hypertension, and hyperlipidemia, increases the morbidity and mortality of cardiovascular disease, type 2 diabetes, nonalcoholic fatty liver disease, and other metabolic diseases. It is well known that insulin resistance, especially hepatic insulin resistance, is a risk factor for metabolic syndrome. Current research has shown that hepatic fatty acid accumulation can cause hepatic insulin resistance through increased gluconeogenesis, lipogenesis, chronic inflammation, oxidative stress and endoplasmic reticulum stress, and impaired insulin signal pathway. Mitochondria are the major sites of fatty acid β-oxidation, which is the major degradation mechanism of fatty acids. Mitochondrial dysfunction has been shown to be involved in the development of hepatic fatty acid–induced hepatic insulin resistance. Mitochondrial autophagy (mitophagy), a catabolic process, selectively degrades damaged mitochondria to reverse mitochondrial dysfunction and preserve mitochondrial dynamics and function. Therefore, mitophagy can promote mitochondrial fatty acid oxidation to inhibit hepatic fatty acid accumulation and improve hepatic insulin resistance. Here, we review advances in our understanding of the relationship between mitophagy and hepatic insulin resistance. Additionally, we also highlight the potential value of mitophagy in the treatment of hepatic insulin resistance and metabolic syndrome.

Secondary Metabolites, Dietary Fiber and Conjugated Fatty Acids as Functional Food Ingredients against Overweight and Obesity

Obesity is a common serious health problem leading to many serious health disorders. This phenomenon is defined as the over-storage of lipids in adipose tissue that occurs when there is an imbalance between the energy intake and energy used. During obesity, many metabolic alterations occur that can damage several organs, such as vascular or skeletal muscle resulting in the dysfunction of these tissues. In this review, we will discuss molecular genetics and causes of obesity, some of the disorders related to human obesity as well as anti-obesity tool. An interesting solution to the obesity problem is natural substances, revealing anti-obesity activity, as well as functional food enriched with aforementioned substances. Functional foods are products exhibiting a potentially positive effect on health beyond basic nutrition. They contain well-known biologically active natural compounds, which promote optimal health and reduce the risk of many diseases, including obesity.