Grape seed procyanidin B2 ameliorates hepatic lipid metabolism disorders in db/db mice

Self-assembled Abietic acid encapsulated nanoparticles to improve the stability of Proanthocyanin B2

Procyanidin B2 (Pac B2) has attracted much attention due to its strong antioxidant activity, but poor in vivo stability limits its wide application in food and medicine. In this paper, composite nanoparticles (NPs) were constructed using abietic acid (AA) as a carrier, which significantly enhanced Pac B2 stability. A spherical morphology and average diameter of 396.05 nm were observed in AA-Pac B2 NPs synthesized by solvent co-precipitation. Pac B2 encapsulation was 11.28 %, and thermal stability is improved. Infrared, Ultraviolet spectrum, and MD (molecular dynamics) spectroscopy revealed hydrogen bonding and hydrophobic interaction between AA and Pac B2. For up to 2 h at 37 °C, Pac B2 can be sustainably released in simulated gastric and intestinal fluids. In vitro, AA-Pac B2 NPs at the same concentration exhibited higher bioavailability and uptake efficiency than free Pac B2. The data demonstrate the potential of AA NPs for improving polyphenol thermal stability and bioavailability.

Traditional Chinese medicine and plant-derived natural products in regulating triglyceride metabolism: Mechanisms and therapeutic potential

The incidence of cardiometabolic disease is increasing globally, with a trend toward younger age of onset. Among these, atherosclerotic cardiovascular disease is a leading cause of mortality worldwide. Despite the efficacy of traditional lipid-lowering drugs, such as statins, in reducing low-density lipoprotein cholesterol levels, a significant residual risk of cardiovascular events remains, which is closely related to unmet triglyceride (TG) targets. The clinical application of current TG-lowering Western medicines has certain limitations, necessitating alternative or complementary therapeutic strategies. Traditional Chinese medicine (TCM) and plant-derived natural products, known for their safety owing to their natural origins and diverse biological activities, offer promising avenues for TG regulation with potentially fewer side effects. This review systematically summarises the mechanisms of TG metabolism and subsequently reviews the regulatory effects of TCM and plant-derived natural products on TG metabolism, including the inhibition of TG synthesis (via endogenous and exogenous pathways), promotion of TG catabolism, regulation of fatty acid absorption and transport, enhancement of lipophagy, modulation of the gut microbiota, and other mechanisms. In conclusion, through a comprehensive analysis of recent studies, this review consolidates the multifaceted regulatory roles of TCM and plant-derived natural products in TG metabolism and elucidates their potential as safer, multi-target therapeutic agents in managing hypertriglyceridemia and mitigating cardiovascular risk, thereby providing a basis for new drug development.

A new direction in Chinese herbal medicine ameliorates for type 2 diabetes mellitus: Focus on the potential of mitochondrial respiratory chain complexes

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes is a common chronic disease. Chinese herbal medicine (CHM) has a history of several thousand years in the treatment of diabetes, and active components with hypoglycemic effects extracted from various CHM, such as polysaccharides, flavonoids, terpenes, and steroidal saponins, have been widely used in the treatment of diabetes.

AIM OF THE STUDY

Research exploring the potential of various CHM compounds to regulate the mitochondrial respiratory chain complex to improve type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

The literature data were primarily obtained from authoritative databases such as PubMed, CNKI, Wanfang, and others within the last decade. The main keywords used include "type 2 diabetes mellitus", "Chinese medicine", "Chinese herbal medicine", "mitochondrial respiratory chain complex", and "mitochondrial dysfunction".

RESULTS

Chinese herbal medicine primarily regulates the activity of mitochondrial respiratory chain complexes in various tissues such as liver, adipose tissue, skeletal muscle, pancreatic islets, and small intestine. It improves cellular energy metabolism through hypoglycemic, antioxidant, anti-inflammatory and lipid-modulating effects. Different components of CHM can regulate the same mitochondrial respiratory chain complexes, while the same components of a particular CHM can regulate different complex activities. The active components of CHM target different mitochondrial respiratory chain complexes, regulate their aberrant changes and effectively improve T2DM and its complications.

CONCLUSION

Chinese herbal medicine can modulate the function of mitochondrial respiratory chain complexes in various cell types and exert their hypoglycemic effects through various mechanisms. CHM has significant therapeutic potential in regulating mitochondrial respiratory chain complexes to improve T2DM, but further research is needed to explore the underlying mechanisms and conduct clinical trials to assess the safety and efficacy of these medications. This provides new perspectives and opportunities for personalized improvement and innovative developments in diabetes management.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

Effect of Grape Seed Proanthocyanidins on Fat Metabolism and Adipocytokines in Obese Rats

This study aimed to investigate the effect of Grape Seed Proanthocyanidin (GSP) on fat metabolism and adipocytokines in obese rats. Fifty 5-week-old rats were randomly assigned to five groups (n = 10 per group) and given either a basal diet, a high-fat diet, or a high-fat diet supplemented with GSP (25, 50, and 100 mg/d) per group. The experiment lasted for five weeks, including a one-week adaptation period and a four-week treatment period. At the end of the experimental period, serum and adipose tissue samples were collected and analyzed. Additionally, we co-cultured 3T3-L1 preadipocytes with varying concentrations of GSP to explore its effect on adipocyte metabolism. The results demonstrated that GSP supplementation reduced weight, daily gain, and abdominal fat weight coefficient (p < 0.05). It also decreased levels of glucose, cholesterol (TC) (p < 0.05), triglycerides (TG) (p < 0.05), low-density lipoprotein (LDL), cyclooxygenase-2 (COX-2), and interleukin-6 (IL-6) in adipose tissue. Furthermore, GSP addition caused adipocyte crumpling in vitro and reduced the mRNA expression of COX-2, LEP, and TNF-α in adipocytes in vitro. These findings provide compelling evidence for exploring the role of GSP in the prevention and treatment of obesity and related diseases.

The Protective Role of Grape Seed in Obesity and Lipid Profile: An Updated Narrative Overview of Preclinical and Clinical Studies

Obesity and dyslipidemia are common disorders universally. According to the acquired outcomes of recent studies, dietary supplementations which have great content of phenolic compounds exert protective effects against obesity and dyslipidemia. Grape [Vitis vinifera] seeds are considered attractive sources of phenolic compounds with anti-oxidative stress and anti-inflammatory effects. There are also various experimental studies describing hepatoprotective, neuroprotective, anti-aging, cardioprotective, and anti-carcinogenic effects of polyphenols isolated from grape seed, highlighting the therapeutic and biological aspects of proanthocyanidins. The present review article first discusses pharmacological, botanical, toxicological, and phytochemical characteristics of Vitis vinifera seeds and afterward designates the protective properties which are attributed to the intake of grape seeds in obesity and hyperlipidemia. Overall valuable and updated findings of this study display that polyphenol of grape seeds has meaningful impacts on the regulation of lipid profile levels and management of obesity.

Extraction of Phytochemicals from Maypole Apple by Subcritical Water

The Maypole apple is a new, promising species of small apples with a prominent flavor and deep red flesh and peel. This study divided Maypole apples into outer flesh, inner flesh, and peel, and used subcritical water at 100–175 °C for 10–30 min to extract various phytochemicals (procyanidin B2 (PB2), 5-caffeoylquinic acid (5CQA), and epicatechin). The obtained Maypole apple extracts and extraction residues in this work were analyzed using a SEM, HPLC, FT-IR, and UV-Vis spectrophotometer. Under different subcritical water extraction conditions, this work found the highest extraction rate: to be PB2 from the peel (4.167 mg/mL), 5CQA (2.296 mg/mL) and epicatechin (1.044 mg/mL) from the inner flesh. In addition, this work regressed the quadratic equations of the specific yield through ANOVA and found that temperature is a more significant affecting factor than extraction time. This aspect of the study suggests that phytochemicals could be obtained from the Maypole apple using the new extraction method of subcritical water.

Antioxidant procyanidin B2 protects oocytes against cryoinjuries via mitochondria regulated cortical tension

BACKGROUND

Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation. Antioxidants were always used to antagonist the oxidative stress caused by vitrification. However, the comprehensive mechanism underlying the protective role of antioxidants has not been studied. Procyanidin B2 (PCB2) is a potent natural antioxidant and its functions in response to vitrification are still unknown. In this study, the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored, and the mechanisms underlying the protective role of PCB2 were systematically elucidated.

RESULTS

Vitrification induced a marked decline in oocyte quality, while PCB2 could improve oocyte viability and further development after parthenogenetic activation. A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress, rescued mitochondrial dysfunction, and improved cell viability. Moreover, PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties. Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration, ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes. Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation, and PCB2 effectively increased the cortical tension through the electron transfer chain pathway. Additionally, PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality. What's more, targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism.

CONCLUSIONS

Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.

Impairment of Mitochondrial Respiration in Metabolic Diseases: An Overview

Mitochondrial dysfunction has emerged as a central pathomechanism in the setting of obesity and diabetes mellitus, linking these intertwined pathologies that share insulin resistance as a common denominator. High-resolution respirometry (HRR) is a state-of-the-art research method currently used to study mitochondrial respiration and its impairment in health and disease. Tissue samples, cells or isolated mitochondria are exposed to various substrate-uncoupler-inhibitor-titration protocols, which allows the measurement and calculation of several parameters of mitochondrial respiration. In this review, we discuss the alterations of mitochondrial bioenergetics in the main dysfunctional organs that contribute to the development of the obese and diabetic phenotypes in both animal models and human subjects. Herein we review data regarding the impairment of oxidative phosphorylation as integrated mitochondrial function assessed by means of HRR. We acknowledge the critical role of this method in determining the alterations in oxidative phosphorylation occurring in the early stages of metabolic pathologies. We conclude that there is a mutual two-way relationship between mitochondrial dysfunction and insulin insensitivity that characterizes these diseases.

S100A9 promotes inflammatory response in diabetic nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has been previously shown to be associated with diabetes mellitus (DM) which is one of the most decisive risk factors for the faster progression of NAFLD to nonalcoholic steatohepatitis (NASH), fibrosis or advanced cirrhosis. However, the critical molecular pathway involved in the development of diabetic-induced liver injury is unclear. By the proteomic study of liver from high-fat diet (HFD)/streptozotocin(STZ)-induced diabetic mice, we revealed that the upregulation of S100A9 was involved in the development of NAFLD with DM. Moreover, we found that S100A9 silencing decreased proinflammatory response and inhibited the TLR4-NF-κB signaling in in-vitro study. Our findings provide new perspectives into the pivotal role of S100A9 for development of diabetic NAFLD and revealed that S100A9 is a critical molecule that links liver injury to inflammation of NAFLD with DM.

Procyanidin B2 suppresses hyperglycemia‑induced renal mesangial cell dysfunction by modulating CAV‑1‑dependent signaling

The dysfunction of renal mesangial cells (MCs) is a hallmark of diabetic kidney disease (DKD), which triggers glomerulosclerosis leading to end-stage renal disease. Procyanidin B2 (PB2), the main component of proanthocyanidin, is well known for its antioxidant and anti-inflammatory effects; however, it remains unclear as to whether it has protective effects on DKD. The present study investigated the protective effect of PB2 against hyperglycemia-induced renal MC dysfunction in mouse SV40-Mes13 (Mes13) cells. The Mes13 cells were treated with or without PB2 under HG conditions. Cell proliferation was assessed using an MTT assay and oxidative stress was assessed by examining intracellular ROS generation and H₂O₂ production. The changes in extracellular matrix accumulation- and cellular inflammation-related proteins were measured by western blot analysis, ELISA and immunofluorescence analysis. The results showed that PB2 treatment markedly attenuated hyperglycemia-induced cell proliferation, oxidative stress, extracellular matrix accumulation and cellular inflammation in Mes13 cells, which was accompanied by an inactivation of redoxosomes, TGF-β1/SMAD and IL-1β/TNF-α/NF-κB signaling pathways. The present study also demonstrated that hyperglycemia upregulated and activated caveolin-1 (CAV-1), whereas PB2 treatment potently reversed this effect. In accordance, CAV-1 overexpression abolished the protective effects of PB2 against hyperglycemia in Mes13 cells, indicating that the cytoprotective effect of PB2 was CAV-1-dependent. These findings form the basis of the potential clinical applications of PB2 in the treatment of DKD.

Procyanidin B2 Protects Aged Oocytes Against Meiotic Defects Through Cortical Tension Modulation

Defects in meiotic process are the main factors responsible for the decreased developmental competence in aged oocytes. Our recent research indicated that natural antioxidant procyanidin B2 (PCB2) promoted maturation progress in oocytes from diabetic mice. However, the effect of PCB2 on aging-induced chromosome abnormalities and the underlying mechanism have not been explored. Here, we found that PCB2 recovered aging-caused developmental arrest during meiotic maturation, germinal vesicle breakdown (GVBD) rate was significantly higher in aged oocytes treated with PCB2 (P < 0.05). Furthermore, we discovered that cortical mechanics were altered during aging process, cortical tension-related proteins were aberrantly expressed in aged oocytes (P < 0.001). PCB2 supplementation efficaciously antagonized aging-induced decreased cortical tension (P < 0.001). Moreover, PCB2 restored spindle morphology (P < 0.01), maintained proper chromosome alignment (P < 0.05), and dramatically reduced reactive oxygen species (ROS) level (P < 0.05) in aged oocytes. Collectively, our results reveal that PCB2 supplementation is a feasible approach to protect oocytes from reproductive aging, contributing to the improvement of oocytes quality.

Dietary Intake of Hydrolyzable Tannins and Condensed Tannins to Regulate Lipid Metabolism

Lipid metabolism disorder is a multifactor issue, which contributes to several serious health consequences, such as obesity, hyperlipidemia, atherosclerosis diabetes, non-alcoholic fatty liver etc. Tannins, applied as natural derived plant, are commonly used in the study of lipid metabolism disease with excellent safety and effectiveness, while producing less toxic and side effects. Meanwhile, recognition of the significance of dietary tannins in lipid metabolism disease prevention has increased. As suggested by existing evidence, dietary tannins can reduce lipid accumulation, block adipocyte differentiation, enhance antioxidant capacity, increase the content of short-chain fatty acids, and lower blood lipid levels, thus alleviating lipid metabolism disorder. This study is purposed to sum up and analyze plenty of documents on tannins, so as to provide the information required to assess the lipid metabolism of tannins.

Procyanidins: From Agro-Industrial Waste to Food as Bioactive Molecules

Procyanidins are an important group of bioactive molecules known for their benefits to human health. These compounds are promising in the treatment of chronic metabolic diseases such as cancer, diabetes, and cardiovascular disease, as they prevent cell damage related to oxidative stress. It is necessary to study effective extraction methods for the recovery of these components. In this review, advances in the recovery of procyanidins from agro-industrial wastes are presented, which are obtained through ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, pressurized fluid extraction and subcritical water extraction. Current trends focus on the extraction of procyanidins from seeds, peels, pomaces, leaves and bark in agro-industrial wastes, which are extracted by ultrasound. Some techniques have been coupled with environmentally friendly techniques. There are few studies focused on the extraction and evaluation of biological activities of procyanidins. The identification and quantification of these compounds are the result of the study of the polyphenolic profile of plant sources. Antioxidant, antibiotic, and anti-inflammatory activity are presented as the biological properties of greatest interest. Agro-industrial wastes can be an economical and easily accessible source for the extraction of procyanidins.

Natural Products for the Prevention and Control of the COVID-19 Pandemic: Sustainable Bioresources

Background: The world has been unprecedentedly hit by a global pandemic which broke the record of deadly pandemics that faced humanity ever since its existence. Even kids are well-versed in the terminologies and basics of the SARS-CoV-2 virus and COVID-19 now. The vaccination program has been successfully launched in various countries, given that the huge global population of concern is still far behind to be vaccinated. Furthermore, the scarcity of any potential drug against the COVID-19-causing virus forces scientists and clinicians to search for alternative and complementary medicines on a war-footing basis. Aims and Objectives: The present review aims to cover and analyze the etiology and epidemiology of COVID-19, the role of intestinal microbiota and pro-inflammatory markers, and most importantly, the natural products to combat this deadly SARS-CoV-2 virus. Methods: A primary literature search was conducted through PubMed and Google Scholar using relevant keywords. Natural products were searched from January 2020 to November 2020. No timeline limit has been imposed on the search for the biological sources of those phytochemicals. Interactive mapping has been done to analyze the multi-modal and multi-target sources. Results and Discussion: The intestinal microbiota and the pro-inflammatory markers that can serve the prognosis, diagnosis, and treatment of COVID-19 were discussed. The literature search resulted in yielding 70 phytochemicals and ten polyherbal formulations which were scientifically analyzed against the SARS-CoV-2 virus and its targets and found significant. Retrospective analyses led to provide information about 165 biological sources that can also be screened if not done earlier. Conclusion: The interactive analysis mapping of biological sources with phytochemicals and targets as well as that of phytochemical class with phytochemicals and COVID-19 targets yielded insights into the multitarget and multimodal evidence-based complementary medicines.

Proanthocyanidins and Where to Find Them: A Meta-Analytic Approach to Investigate Their Chemistry, Biosynthesis, Distribution, and Effect on Human Health

Proanthocyanidins (PACs) are a class of polyphenolic compounds that are attracting considerable interest in the nutraceutical field due to their potential health benefits. However, knowledge about the chemistry, biosynthesis, and distribution of PACs is limited. This review summarizes the main chemical characteristics and biosynthetic pathways and the main analytical methods aimed at their identification and quantification in raw plant matrices. Furthermore, meta-analytic approaches were used to identify the main plant sources in which PACs were contained and to investigate their potential effect on human health. In particular, a cluster analysis identified PACs in 35 different plant families and 60 different plant parts normally consumed in the human diet. On the other hand, a literature search, coupled with forest plot analyses, highlighted how PACs can be actively involved in both local and systemic effects. Finally, the potential mechanisms of action through which PACs may impact human health were investigated, focusing on their systemic hypoglycemic and lipid-lowering effects and their local anti-inflammatory actions on the intestinal epithelium. Overall, this review may be considered a complete report in which chemical, biosynthetic, ecological, and pharmacological aspects of PACs are discussed.

Attenuation of Perfluorooctane Sulfonate-Induced Steatohepatitis by Grape Seed Proanthocyanidin Extract in Mice

Perfluorooctane sulfonate (PFOS), an environmentally persistent pollutant, has been revealed to elicit hepatic toxicity. In the current study, we investigated the protective role of grape seed proanthocyanidin extract (GSPE) against PFOS-caused steatohepatitis in mice. Animals were exposed intragastrically to PFOS (10 mg/kg/day), GSPE (150 mg/kg/day), or their combination. After 21 days of treatment, mice exposed to PFOS exhibited steatosis, oxidative stress, and inflammation in the liver. Nevertheless, simultaneous administration of GSPE resumed the declined serum hepatic enzyme activities and histological abnormalities in PFOS-exposed mice. Furthermore, GSPE supplementation reduced the contents of triglyceride (TG) and total cholesterol (TC) and expression of lipid metabolism-associated genes CD36 and fatty acid-binding protein 4 (FABP4) in the liver of mice treated with PFOS. Moreover, GSPE suppressed the generation of lipid peroxidative product malondialdehyde and restored the activity of superoxide dismutase in the liver of PFOS-exposed mice. In addition, GSPE repressed the PFOS-induced hepatic overproduction of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Our results demonstrate that GSPE attenuates PFOS-caused steatohepatitis in mice by regulating lipid metabolism, oxidative stress, and inflammatory response.

Proanthocyanidins Should Be a Candidate in the Treatment of Cancer, Cardiovascular Diseases and Lipid Metabolic Disorder

The conventional view of using medicines as routine treatment of an intractable disease is being challenged in the face of extensive and growing evidence that flavonoids in foods, especially proanthocyanidins (PAs), can participate in tackling fatal diseases like cancer, cardiovascular and lipid metabolic diseases, both as a precautionary measure or as a dietary treatment. Although medical treatment with medicines will remain necessary in some cases, at least in the short term, PAs’ function as antioxidant, anti-inflammatory drugs, signal pathway regulators remain critical in many diseases. This review article demonstrates the physical and biological properties of PAs, summarizes the health benefits of PAs found by researchers previously, and shows the possibility and importance of being a dietary treatment substance.

Procyanidin B2 improves endothelial progenitor cell function and promotes wound healing in diabetic mice via activating Nrf2

One of the major reasons for the delayed wound healing in diabetes is the dysfunction of endothelial progenitor cells (EPCs) induced by hyperglycaemia. Improvement of EPC function may be a potential strategy for accelerating wound healing in diabetes. Procyanidin B2 (PCB2) is one of the major components of procyanidins, which exhibits a variety of potent pharmacological activities. However, the effects of PCB2 on EPC function and diabetic wound repair remain elusive. We evaluated the protective effects of PCB2 in EPCs with high glucose (HG) treatment and in a diabetic wound healing model. EPCs derived from human umbilical cord blood were treated with HG. The results showed that PCB2 significantly preserved the angiogenic function, survival and migration abilities of EPCs with HG treatment, and attenuated HG‐induced oxidative stress of EPCs by scavenging excessive reactive oxygen species (ROS). A mechanistic study found the protective role of PCB2 is dependent on activating nuclear factor erythroid 2‐related factor 2 (Nrf2). PCB2 increased the expression of Nrf2 and its downstream antioxidant genes to attenuate the oxidative stress induced by HG in EPCs, which were abolished by knockdown of Nrf2 expression. An in vivo study showed that intraperitoneal administration of PCB2 promoted wound healing and angiogenesis in diabetic mice, which was accompanied by a significant reduction in ROS level and an increase in circulating EPC number. Taken together, our results indicate that PCB2 treatment accelerates wound healing and increases angiogenesis in diabetic mice, which may be mediated by improving the mobilization and function of EPCs.

Grape seed extract supplementation along with a restricted-calorie diet improves cardiovascular risk factors in obese or overweight adult individuals: A randomized, placebo-controlled trial

Grape seed extract (GSE) is a flavonoid-rich supplement, recently discussed as a potential moderator of inflammation and obesity. In this study, we aimed to investigate the effects of GSE supplementation along with a restricted-calorie diet (RCD), on changes in blood lipid profile, visceral adiposity index (VAI), and atherogenic index of plasma (AIP). We designed a randomized, double-blinded, placebo-controlled clinical trial. Forty obese or overweight individuals (25 ≤ body mass index < 40 kg/m² ) were randomly assigned to receive GSE (300 mg/day) or placebo, plus RCD, for 12 weeks. We studied the anthropometric measures, biochemical biomarkers and dietary intake within the study timelines. Levels of high-density lipoprotein cholesterol (HDL-C) and HDL-C/low-density lipoprotein cholesterol (LDL-C) significantly increased in the GSE group as compared with the placebo group at week 12 (p = .03 and .008, respectively, adjusted for age, sex, energy and saturated fatty acid intake). We also observed a significant reduction in LDL-C following GSE supplementation in comparison to placebo (adjusted for age, sex and energy intake, p = .04). VAI, AIP, total cholesterol and triglyceride significantly decreased in the GSE group compared with the baseline (p = .04, .02, .01, and .02, respectively). GSE supplementation may have a modulatory role in improving blood lipid profile in obese or overweight individuals, when accompanied by RCD.

Proteomic analysis of liver mitochondria of db/db mice treated with grape seed procyanidin B2

Hepatic damage has been recognized as one of the major complications in diabetes mellitus. Our previous studies have verified that grape seed procyanidin B2 (GSPB2) played a protective effect on hepatic damage of diabetes. We used isobaric tag for relative and absolute quantitation proteomics here to identify the alterant mitochondrial protein profile in diabetic liver and to seek the protective targets of GSPB2. Proteomics found that 171 proteins were upregulated or downregulated in the liver mitochondria of diabetic group compared to the control group. Of these proteins, 61 were normalized after GSPB2 treatment. These back-regulated proteins are involved in the process of fatty acid oxidation, tricarboxylic acid cycle, oxidative phosphorylation, oxidative stress, and apoptosis. Some differentially expressed proteins were confirmed by western blotting. Our study might help to better understand the mechanism of mitochondrial dysfunction in diabetic liver damage, and provide novel targets for estimating the protective effects of GSPB2. PRACTICAL APPLICATIONS: Grape seed procyanidin B2 (GSPB2), a polyphenolic component found in red wine and grapes, has beneficial effects such as antioxidative stress, antiapoptosis, and cardiovascular protection. We used proteomics here to identify the differentially expressed mitochondrial proteins in diabetic liver after GSPB2 treatment and to seek the protective targets of GSPB2. We found that the differentially expressed proteins were involved in carbon metabolism, oxidative phosphorylation, fatty acid metabolism, citrate cycle, oxidative stress, and apoptosis. These proteins may play a key role in diabetic hepatic damage as functional proteins. Targeting these proteins including apply of GSPB2 could potentially lead to an effective treatment in the diabetic hepatic disease.

Metabolic Impact of Flavonoids Consumption in Obesity: From Central to Peripheral

The prevention and treatment of obesity is primary based on the follow-up of a healthy lifestyle, which includes a healthy diet with an important presence of bioactive compounds such as polyphenols. For many years, the health benefits of polyphenols have been attributed to their anti-oxidant capacity as free radical scavengers. More recently it has been described that polyphenols activate other cell-signaling pathways that are not related to ROS production but rather involved in metabolic regulation. In this review, we have summarized the current knowledge in this field by focusing on the metabolic effects of flavonoids. Flavonoids are widely distributed in the plant kingdom where they are used for growing and defensing. They are structurally characterized by two benzene rings and a heterocyclic pyrone ring and based on the oxidation and saturation status of the heterocyclic ring flavonoids are grouped in seven different subclasses. The present work is focused on describing the molecular mechanisms underlying the metabolic impact of flavonoids in obesity and obesity-related diseases. We described the effects of each group of flavonoids in liver, white and brown adipose tissue and central nervous system and the metabolic and signaling pathways involved on them.

Procyanidin B2 Improves Oocyte Maturation and Subsequent Development in Type 1 Diabetic Mice by Promoting Mitochondrial Function

Type 1 diabetes (T1D) results in decreased oocyte quality and compromised early embryonic development. Procyanidin B2 (PB2) is a natural compound extracted from grape seeds and has strong antioxidant activity in vivo. This study evaluated the effect of PB2 on oocyte maturation in diabetic mice. Diabetic mice were induced by streptozotocin (STZ) injection. PB2 was supplemented in the in vitro maturation medium, and the ratio of germinal vesicle breakdown (GVBD) and polar body extrusion (PBE), reactive oxygen species (ROS) levels, mitochondrial function, developmental ability, as well as crotonylation at H4K5 were determined in oocytes. PB2 can promote the extrusion of PBE (88.34% vs. 75.02%, P < 0.05); reduce the generation of ROS (1.12 vs. 1.96, P < 0.05); and improve the level of mitochondrial membrane potential (0.87 vs. 0.79 Δφm, P < 0.05), ATP level (1.31 vs. 0.71 pmol, P < 0.05), and mitochondria temperature (618.25 vs. 697.39 pixels, P < 0.05). The addition of PB2 also improved the level of oocyte crotonylation at H4K5 (crH4K5) (47.26 vs. 59.68 pixels, P < 0.05) and increased the blastocyst rate (61.51% vs. 36.07%, P < 0.05) after parthenogenetic activation. Our results are the first to reveal a role for PB2 in promoting the viability of oocytes by regulating the mitochondrial function. Moreover, we uncover that PB2 can improve the level of crH4K5, which provides a new strategy to combat the decline in oocyte quality of diabetic.

Effects of Flavanols on Enteroendocrine Secretion

Some beneficial effects of grape seed proanthocyanidin extract (GSPE) can be explained by the modulation of enterohormone secretion. As GSPE comprises a combination of different molecules, the pure compounds that cause these effects need to be elucidated. The enterohormones and chemoreceptors present in the gastrointestinal tract differ between species, so if humans are to gain beneficial effects, species closer to humans-and humans themselves-must be used. We demonstrate that 100 mg/L of GSPE stimulates peptide YY (PYY) release, but not glucagon-like peptide 1 (GLP-1) release in the human colon. We used a pig ex vivo system that differentiates between apical and basolateral intestinal sides to analyse how apical stimulation with GSPE and its pure compounds affects the gastrointestinal tract. In pigs, apical GSPE treatment stimulates the basolateral release of PYY in the duodenum and colon and that of GLP-1 in the ascending, but not the descending colon. In the duodenum, luminal stimulation with procyanidin dimer B2 increased PYY secretion, but not CCK secretion, while catechin monomers (catechin/epicatechin) significantly increased CCK release, but not PYY release. The differential effects of GSPE and its pure compounds on enterohormone release at the same intestinal segment suggest that they act through chemosensors located apically and unevenly distributed along the gastrointestinal tract.

The role of diosgenin in diabetes and diabetic complications

Diabetes mellitus is a chronic and common metabolic disease that seriously endangers human health. Hyperglycemia and long-term metabolic disorders in diabetes will cause damage to the whole body tissues and organs, resulting in serious complications. Nowadays, drugs for treating diabetes on the market has strong side effects, new treatments thus are urgently needed. Natural therapy of natural ingredients is a promising avenue, this is because natural ingredients are safer and they also show strong activity in the treatment of diabetes. Diosgenin is such a very biologically active natural steroidal sapogenin. The research of diosgenin in the treatment of diabetes and its complications has been widely reported. This article reviews the effects of diosgenin through multiple targets and multiple pathways in diabetes and its complications which including diabetic nephropathy, diabetic liver disease, diabetic neuropathy, diabetic vascular disease, diabetic cardiomyopathy, diabetic reproductive dysfunction, and diabetic eye disease.

Sesamol Alleviates Obesity-Related Hepatic Steatosis via Activating Hepatic PKA Pathway

This study aimed to investigate the effect of sesamol (SEM) on the protein kinase A (PKA) pathway in obesity-related hepatic steatosis treatment by using high-fat diet (HFD)-induced obese mice and a palmitic acid (PA)-treated HepG2 cell line. SEM reduced the body weight gain of obese mice and alleviated related metabolic disorders such as insulin resistance, hyperlipidemia, and systemic inflammation. Furthermore, lipid accumulation in the liver and HepG2 cells was reduced by SEM. SEM downregulated the gene and protein levels of lipogenic regulator factors, and upregulated the gene and protein levels of the regulator factors responsible for lipolysis and fatty acid β-oxidation. Meanwhile, SEM activated AMP-activated protein kinase (AMPK), which might explain the regulatory effect of SEM on fatty acid β-oxidation and lipogenesis. Additionally, the PKA-C and phospho-PKA substrate levels were higher after SEM treatment. Further research found that after pretreatment with the PKA inhibitor, H89, lipid accumulation was increased even with SEM administration in HepG2 cells, and the effect of SEM on lipid metabolism-related regulator factors was abolished by H89. In conclusion, SEM has a positive therapeutic effect on obesity and obesity-related hepatic steatosis by regulating the hepatic lipid metabolism mediated by the PKA pathway.

The Preventative Effects of Procyanidin on Binge Ethanol-Induced Lipid Accumulation and ROS Overproduction via the Promotion of Hepatic Autophagy

SCOPE

Autophagy plays an important role in alleviating alcoholic liver disease (ALD). In this study, it is discovered that a dimer procyanidin (DPC) significantly prevented ALD by promoting hepatic autophagy.

METHODS AND RESULTS

Both cell and animal disease models stimulated by excessive ethanol are employed to evaluate the protective actions of DPC. Specifically, in vitro, DPC significantly decreased intracellular lipid deposition, diminished reactive oxygen species (ROS) formation, and elevated the level of mitochondrial membrane potential. These beneficial effects can be remarkably blocked by 3-methyladenine, a potent autophagy inhibitor, suggesting the autophagy-dependent protective role of DPC. In vivo, DPC pretreatment can also significantly reduce lipid accumulation, ROS overproduction, and elevated GSH content in the liver. Similarly, these protective effects of DPC can be partially reversed by chloroquine, a lysosomal inhibitor used to block the late-stage autophagy flux. Moreover, the determinations of LC3 and p62 protein expressions, autophagic flux assessments, and transmission electron microscopy observation further demonstrate the pro-autophagic effect of DPC.

CONCLUSIONS

DPC may activate hepatic autophagy to eliminate lipid droplets and damaged mitochondria, thereby reducing hepatic lipid disposition and ROS overproduction. This study demonstrates that DPC is a protective reagent on ALD, providing a novel strategy of fighting ALD.

Optimizing Nucleophilic Depolymerization of Proanthocyanidins in Grape Seeds to Dimeric Proanthocyanidin B1 or B2

Depolymerization of polymeric proanthocyanidins (PPCs) in grape seeds into oligomeric proanthocyanidins (OPCs), especially the dimers, has important academic significance and practical value. Reaction conditions including nucleophilic reagent/PPC mass ratio, HCl concentration, reaction time, and temperature were systematically optimized by central composite design to maximize the yield of the dimeric product B2 or B1. The yield of B2 reached 3.35 mg mL^-1 under the conditions of (-)-epicatechin/PPC mass ratio 2.8, HCl concentration 0.06 mol, reaction time 16 min and temperature 36 °C, and that of B1 reached 3.64 mg mL^-1 under the conditions of (+)-catechin/PPC mass ratio 2.8, HCl concentration 0.07 mol, reaction time 17 min, and temperature 34 °C. Overall, this study has provided theoretical guidance and a practical approach to improvethe reaction process and economic value of proanthocyanidins in grape seed proanthocyanidin extract.

9-O-benzoyl-substituted berberine exerts a triglyceride-lowering effect through AMPK signaling pathway in human hepatoma HepG2 cells

Berberine is an isoquinoline alkaloid extracted from Rhizoma coptidis and shows anti-hyperlipidemia effect in vivo and in vitro. We previously found that berberine could decrease the intracellular triglyceride content in human hepatoma HepG2 cells through activation of AMP-activated protein kinase (AMPK), a major regulator of lipid metabolism. Herein, to find a more effective agent, several berberine analogues (A1-A13) were isolated and synthesized, and the triglyceride-lowering effects and potential mechanisms were investigated in HepG2 cells. Among these berberine analogues, 9-O-benzoyl-substituted berberine (A13) showed strong affinity to AMPK and significantly up-regulated the levels of phospho-Thr172 AMPK α subunit. Meanwhile, A13 reduced the cellular triglyceride levels. Furthermore, A13 could mediate the mRNA levels of downstream proteins involved in triglyceride synthesis and fatty acid oxidation of AMPK signaling pathway. These results suggested that A13 exerts a triglyceride-lowering effect via stimulation of AMPK pathway, which may be beneficial to regulate hyperlipidemia.

Achacha (Garcinia humilis) Rind Improves Cardiovascular Function in Rats with Diet-Induced Metabolic Syndrome

Garcinia humilis is a fruit known as achachairú. It is native to South American countries such as Bolivia, Peru, and Brazil, but it is also cultivated as achacha in northern Australia. The aim of this study was to determine the phytochemicals in achacha rind and pulp and to investigate these components as potential treatments for the symptoms of metabolic syndrome. Both rind and pulp contain procyanidins and citric acid rather than hydroxycitric acid. Male Wistar rats (8⁻9 weeks old) were fed with either high-carbohydrate, high-fat, or corn starch diets for 16 weeks. Intervention groups were fed with either diet supplemented with 1.5% G. humilis rind powder or 2.0% G. humilis pulp for the last 8 weeks of the protocol. Rats fed a high-carbohydrate, high-fat diet exhibited hypertension, dyslipidemia, central obesity, impaired glucose tolerance, and non-alcoholic fatty liver disease. G. humilis rind decreased systolic blood pressure, diastolic stiffness, left ventricular inflammatory cell infiltration, and collagen deposition in high-carbohydrate, high-fat diet-fed rats. However, there was no change in glucose tolerance, body weight, or body composition. Therefore, G. humilis rind, usually a food by-product, but not the edible pulp, showed potential cardioprotection with minimal metabolic changes in a rat model of diet-induced metabolic syndrome.

Procyanidin B2 ameliorates free fatty acids-induced hepatic steatosis through regulating TFEB-mediated lysosomal pathway and redox state

Procyanidin B2, a naturally occurring phenolic compound, has been reported to exert multiple beneficial functions. However, the effect of procyanidin B2 on free fatty acids (FFAs)-induced hepatic steatosis remains obscure. The present study is therefore aimed to elucidate the protective effect of procyanidin B2 against hepatic steatosis and its underlying mechanism. Herein, we reported that procyanidin B2 attenuated FFAs-induced lipid accumulation and its associated oxidative stress by scavenging excessive ROS and superoxide anion radicals, blocking loss of mitochondrial membrane potential, restoring glutathione content, and increasing activity of antioxidant enzymes (GPx, SOD and CAT) in hepatocytes. Procyanidin B2 mechanistically promoted lipid degradation via modulation of transcription factor EB (TFEB), a master regulator of lysosomal pathway. Molecular docking analysis indicated a possible ligand-binding position of procyanidin B2 with TFEB. In addition, administration of procyanidin B2 resulted in a significant reduction of hepatic fat accumulation in high-fat diet (HFD)-induced obese mice, and also ameliorated HFD-induced metabolic abnormalities, including hyperlipidemia and hyperglycemia. It was confirmed that procyanidin B2 prevented HFD-induced hepatic fat accumulation through down-regulating lipogenesis-related gene expressions (PPARγ, C/EBPα and SREBP-1c), inhibiting pro-inflammatory cytokines production (IL-6 and TNF-α) and increasing antioxidant enzymes activity (GPx, SOD and CAT). Moreover, hepatic fatty acids analysis indicated that procyanidin B2 caused a significant increase in the levels of palmitic acid, oleic acid and linoleic acid. Intriguingly, procyanidin B2 restored the decreased nuclear TFEB expression in HFD-induced liver steatosis and up-regulated its target genes involved in lysosomal pathway (Lamp1, Mcoln, Uvrag), which suggested a previously unrecognized mechanism of procyanidin B2 on ameliorating HFD-induced hepatic steatosis. Taken together, our results demonstrated that procyanidin B2 attenuated FFAs-induced hepatic steatosis through regulating TFEB-mediated lysosomal pathway and redox state, which had important implications that modulation of TFEB might be a potential therapeutic strategy for hepatic steatosis and procyanidin B2 could represent a promising novel agent in the prevention and treatment of non-alcoholic fatty liver disease (NAFLD).