Cinnamon polyphenols regulate multiple metabolic pathways involved in insulin signaling and intestinal lipoprotein metabolism of small intestinal enterocytes

Exploring the Antioxidative Effects of Ginger and Cinnamon: A Comprehensive Review of Evidence and Molecular Mechanisms Involved in Polycystic Ovary Syndrome (PCOS) and Other Oxidative Stress-Related Disorders

Oxidative stress represents the pathophysiological basis for most disorders, including reproductive issues. Polycystic ovary syndrome (PCOS) is heterogeneous endocrine disorder of women characterized primarily by irregular menstrual cycles, hyper-androgenism, and ovulatory dysfunction. In the last decades, PCOS was recognized as a systemic silent inflammation and an oxidative disturbance-related disorder, exerting multifaceted symptoms, including metabolic. PCOS treatment should involve a personalized approach tailored to individual symptoms; however, the results are often unsatisfactory. Various supplementary treatments have been proposed to assist in the management and alleviation of PCOS symptoms. Cinnamon and ginger, known for millennia as herbs used in spices or traditional medicine for the treatment of various diseases, are of interest in this study. The aim of this study is to evaluate and investigate the effects of cinnamon and ginger in PCOS patients. Using relevant keywords we searched through PubMed/MEDLINE, Science Direct, Google Scholar and Web of science to find animal studies, pre-clinical, and clinical studies which were then reviewed for usage. Out of all of the reviewed studies a total of 65 studies were included in this review article. Cinnamon and ginger can affect hormonal status, lipid profile, obesity, and insulin resistance by mitigating oxidative stress and inflammation. Generally, based on current clinical evidence, it was revealed that supplementation with cinnamon or ginger had a useful impact in patients with PCOS. This review summarizes the antioxidative effects of ginger and cinnamon in PCOS treatment, highlighting their potential benefits in other oxidative stress-related pathologies.

Regulating microsomal triglyceride transfer protein with natural products for the treatment of hyperlipidaemia

Hyperlipidaemia, characterised by elevated levels of lipids, particularly LDL-C, is a significant risk factor for atherosclerotic cardiovascular disease. While synthetic inhibitors of microsomal triglyceride transfer protein (MTP) have shown potential in lowering LDL-C, they are associated with adverse effects. This study explores a novel approach by screening natural products to identify plant extracts that down-regulate MTP gene expression, aiming to reduce hyperlipidaemia with fewer side effects. Modulating MTP expression, rather than direct inhibition, offers a promising avenue for lowering plasma lipids and mitigating cardiovascular risk. Various plant extracts were examined for their potential as MTP down-regulators, with Liquorice root and Pomegranate rind extracts demonstrating the highest efficacy. Additionally, the study assessed the total phenolic content of these extracts, revealing their -antioxidant capacity. This research provides a foundation for further investigation into bioactive molecules as potential anti-hyperlipidemic agents with improved safety profiles, addressing a critical need in cardiovascular disease prevention.

Effects of Cinnamon (Cinnamomum zeylanicum) Extract on Adipocyte Differentiation in 3T3-L1 Cells and Lipid Accumulation in Mice Fed a High-Fat Diet

Flavonoids and phenolic acid are two of the rich polyphenols found in cinnamon (Cinnamomum zeylanicum). The effects of cinnamon extract on the inhibition of adipocyte differentiation in 3T3-L1 fibroblast cells and prohibitory lipid accumulation in male mice fed a high-fat diet were examined. Upon treating 3T3-L1 cells with cinnamon for 3 days, the cinnamon inhibited lipid accumulation and increased gene expression levels, such as those of adiponectin and leptin. In in vivo experiments, mice were randomized into four groups after a one-week acclimation period, as follows: normal diet, normal diet + 1% cinnamon extract, high-fat diet, and high-fat diet + 1% cinnamon extract. After 14 weeks of supplementation, we found that cinnamon extract increased the expression of lipolysis-related proteins, such as AMPK, p-ACC, and CPT-1, and reduced the expression of lipid-synthesis-related proteins, such as SREBP-1c and FAS, in liver tissue. Our results show that cinnamon extract may exhibit anti-obesity effects via the inhibition of lipid synthesis and adipogenesis and the induction of lipolysis in both 3T3-L1 fibroblast cells and mice fed a high-fat diet. Accordingly, cinnamon extract may have potential anti-obesity effects.

Cinnamon as a Complementary Therapeutic Approach for Dysglycemia and Dyslipidemia Control in Type 2 Diabetes Mellitus and Its Molecular Mechanism of Action: A Review

The scientific evidence that cinnamon may exert beneficial effects on type 2 diabetes mellitus due to the biological activity of its bioactive compounds has been increasing in recent years. This review provides an overview of the effects of cinnamon on clinical parameters of diabetes and summarizes the molecular mechanisms of action of cinnamon on glucose and lipid metabolism. Search criteria include an electronic search using PubMed, Medline, and Cochrane Library databases. English literature references from 2000 up to 2022 were included. Following title and abstract review, full articles that met the inclusion criteria were included. The results from the available evidence revealed that cinnamon improved glycemic and lipidemic indicators. Clinical trials clarified that cinnamon also possesses an anti-inflammatory effect, which may act beneficially in diabetes. Based on in vitro and in vivo studies, cinnamon seems to elicit the regulation of glucose metabolism in tissues by insulin-mimetic effect and enzyme activity improvement. Furthermore, cinnamon seems to decrease cholesterol and fatty acid absorption in the gut. The current literature search showed a considerable number of studies on diabetic subjects. Some limitations in comparing published data should be highlighted, including variability in doses, extracts and species of cinnamon, administration forms, and antidiabetic therapy.

Cinnamon could improve hepatic steatosis caused by a high-fat diet via enhancing hepatic beta-oxidation and inhibiting hepatic lipogenesis, oxidative damage, and inflammation in male rats

Obesity is a health and medical problem and is known as the accumulation of fat that increases the risk of cardiovascular, type 2 diabetes mellitus, and infertility. Cinnamon is a spice that is used mainly as a flavoring additive and folk remedies to treat diabetes. Molecular mechanisms of its effects on hepatic lipogenesis and beta-oxidation, inflammation, and oxidative damage are not fully understood. Therefore, the aim of this study was to evaluate the protective and therapeutic effect of different doses of cinnamon in obese male rats. Forty-eight adult male Wister rats were randomly assigned into eight controlled and treated groups. Serum levels of lipid, glucose, and insulin profiles were measured along with liver levels of antioxidant enzymes, MDA and TNF-α. Hepatic expression of genes involved in beta-oxidation, lipogenesis, oxidative stress, and inflammation was also evaluated. Hepatic levels of oxidative and inflammatory biomarkers and serum levels of glucose, liver enzymes, insulin, and lipid profiles increased significantly in obese rats. Moreover, hepatic expression of SREBP-1c and NF-κB increased, and PPAR-alpha, CD36, FAS, CPT-1, and Nrf-2 decreased in obese rats. However, pretreatment and treatment with different doses of cinnamon in obese rats could significantly ameliorate them in obese rats. It can be concluded that cinnamon could improve hepatic steatosis caused by a high-fat diet via enhancing hepatic beta-oxidation and inhibiting hepatic lipogenesis, oxidative damage, and inflammation in male rats. PRACTICAL APPLICATIONS: Obesity as a medical and psychiatric problem is seen in more than a third of the world's population. Obesity leads to cardiovascular disease, diabetes, and in some cases even death. Cinnamon as a spice and folk remedy has long been used as a treatment for obesity and liver disease. Cinnamon has received a great of attention from the past to the present due to its pharmacological properties and in addition to its availability, cheapness and low side effects. Cinnamon can prevent dyslipidemia, hyperglycemia, oxidative damage, and inflammation by modulating multiple signaling pathways. Our results showed that cinnamon could improve hepatic steatosis caused by HFD via enhancing hepatic beta-oxidation and inhibiting hepatic lipogenesis, oxidative damage, and inflammation. Therefore, it can be recommended that cinnamon and its products can be used as a very suitable option for the production of pharmaceutical supplements for the prevention and treatment of metabolic diseases.

Beneficial effects of cinnamon and its extracts in the management of cardiovascular diseases and diabetes

Cardiovascular diseases (CVDs) and diabetes are the leading causes of death worldwide, which underlines the urgent necessity to develop new pharmacotherapies. Cinnamon has been an eminent component of spice and traditional Chinese medicine for thousands of years. Numerous lines of findings have elucidated that cinnamon has beneficial effects against CVDs in various ways, including endothelium protection, regulation of immune response, lowering blood lipids, antioxidative properties, anti-inflammatory properties, suppression of vascular smooth muscle cell (VSMC) growth and mobilization, repression of platelet activity and thrombosis and inhibition of angiogenesis. Furthermore, emerging evidence has established that cinnamon improves diabetes, a crucial risk factor for CVDs, by enhancing insulin sensitivity and insulin secretion; regulating the enzyme activity involved in glucose; regulating glucose metabolism in the liver, adipose tissue and muscle; ameliorating oxidative stress and inflammation to protect islet cells; and improving diabetes complications. In this review, we summarized the mechanisms by which cinnamon regulates CVDs and diabetes in order to provide a theoretical basis for the further clinical application of cinnamon.

Impact of Cassia Bark Consumption on Glucose and Lipid Control in Type 2 Diabetes: An Updated Systematic Review and Meta-Analysis

Control of diabetes is a constant challenge and natural remedies are being searched along with modern medicine. The effectiveness of cinnamon in managing it lacks consensus. Besides this, earlier trials had a variant in the type of product they used, quantity, duration, the form of molecules, etc. So, we aimed to measure the impact of cassia ground bark powder consumption, 1-2 gm/day for 90 days, in lowering plasma glucose and lipids among those with type 2 diabetes. The authors searched the PubMed, Medline, Embase, CINAHL, Clinical Key, Ovid, and Scopus databases and the Cochrane Central Register (last search December 30, 2020) with the MeSH terms and keywords of cinnamon, cassia cinnamon, Chinese cinnamon, and type 2 diabetes mellitus to conclude the effects of cassia cinnamon on diabetes based on the evidence of human clinical trials that reported at least one of the following: glycosylated hemoglobin (HbA1C), fasting blood glucose, total cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Weighted mean differences were calculated by using the random-effect model of RevMan software (The Cochrane Collaboration, London, UK), and the pooled analysis found an insignificant reduction of the outcome variable (p>0.05).

Purification, characterization and molecular cloning of a dicaffeoylquinic acid-hydrolyzing esterase from human-derived Lactobacillus fermentum LF-12

Dicaffeoylquinic acids (DiCQAs), the main components of kudingcha made from the leaves of Ilex kudingcha, could be transformed by gut microbiota. However, the information about the related microorganisms and enzymes involved in the biotransformation of DiCQAs in the human gut is limited. Therefore, a strain of bacteria that could hydrolyze DiCQAs, belonging to Lactobacillus fermentum named L. fermentum LF-12, was isolated from human feces in the present study. Furthermore, an esterase for the hydrolysis of DiCQAs was purified from L. fermentum LF-12 and heterogeneously expressed in Escherichia coli. The esterase could be induced to exert superior hydrolytic activity in the presence of lactose as the carbon source. The molecular weight of the purified esterase was determined to be 31.9 kDa, and the isoelectric point, optimal pH and temperature for the esterase were 4.71, 6.5 and 45 °C, respectively. The enzyme activity was improved by Mg2+ and Ca2+, and reduced by Co2+, Cu2+, EDTA and some kinds of organic solvents. The present results provide new insights into the metabolism of DiCQAs by the human gut.

Acute Effects of Cinnamon Spice on Post-prandial Glucose and Insulin in Normal Weight and Overweight/Obese Subjects: A Pilot Study

Clinical studies and meta-analyses have supported the notion that consuming cinnamon spice long term can have beneficial effects in individuals with normal glucose homeostasis and varying degrees of glucose intolerance including type 2 diabetes. The objective of this study was to evaluate the acute effect of cinnamon on the post-prandial responses to a typical American breakfast in normal and overweight/obese participants (ClinicalTrials.gov registration No. NCT04686552). The consumption of a single dose of 6 g of cinnamon added to oatmeal prepared with milk resulted in a significant reduction of one of our primary outcomes post-prandial insulin response (niAUC_0−180min) in overweight/obese participants compared to control consuming breakfast without cinnamon. We also performed exploratory analysis of secondary outcomes. In normal weight participants, we observed a decrease of post-prandial glucagon response (niAUC_0−180min and glucagon levels at 60–120 min) and C-peptide response (30 min) comparing breakfast with to without cinnamon. Cinnamon consumption did not change post-prandial glycemic response in normal weight participants, but increased 60 min post-prandial glucose in overweight/obese participants compared to control. In summary, cinnamon consumption differentially affected post-prandial hormonal responses in normal and overweight/obese participants.

Dietary polyphenol impact on gut health and microbiota

Polyphenols are naturally occurring compounds in plants and they are the most abundant antioxidants in the human diet. Due to their considerable structural diversity, this largely influences their bioavailability. Since a large proportion of polyphenols remains unabsorbed along the gastrointestinal tract, they may accumulate in the large intestine, where most of them are extensively metabolized by the intestinal microbiota. The formation of bioactive polyphenol-derived metabolites may also benefit the health status of the subjects, although the mechanisms have not been delineated. This review aims to highlight the impact of polyphenols on gut health and the modes of action could be through modulation of intestinal barrier function, innate and adaptive immune response, signaling pathways, as well as the ability to modify gut microbiota composition. The review will conclude by presenting future perspective and challenges of polyphenols application in food products to be used for preventing or treating diseases.

Baihu Jia Guizhi Decoction Improves Rheumatoid Arthritis Inflammation by Regulating Succinate/SUCNR1 Metabolic Signaling Pathway

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovitis. Succinate is an inflammatory metabolic signal that exacerbates RA synovitis by activating succinate receptor 1 (SUCNR1) to amplify the release of IL-1β. Thus, inhibition of succinate activation of SUCRN1 could be an effective method to inhibit the inflammation of RA. Baihu Jia Guizhi decoction (BHGZ), which is composed of Gypsum Fibrosum, Anemarrhena asphodeloides Bge., Cinnamomum cassia Presl., Glycyrrhiza uralensis Fisch., and Oryza sativa L., is a Traditional Chinese Medicine (TCM) prescription used to treat RA in clinic. In addition, TCM believes that damp and heat environment is one of the causes of RA. In this study, we tested the role of damp and heat environments in exacerbating RA inflammation and the anti-inflammatory effect of BHGZ, based on succinate/SUCNR1/IL-1β pathway in the adjuvant arthritis (AA) model with damp and heat environment (AA + DHE). Results showed that paw swelling and synovial pathology were significantly increased in AA rats, and these results were aggravated by stimulation in damp and heat environment. BHGZ improved AA + DHE rats' paw swelling, synovial hyperplasia, and inflammatory cell infiltration and reduced IL-1β. In addition, AA rats significantly increased the expression of SUCNR1, and the stimulation of damp and heat environment not only increased the expression of SUCNR1 but also promoted the accumulation of succinate. BHGZ simultaneously reduced the concentration of succinate and the expression of SUCNR1. Finally, SDH activity was decreased in AA rats and AA + DHE rats, while BHGZ increased SDH activity and then reduced succinate concentration. Therefore, we prove that damp and heat environment deteriorated the inflammation of RA which is the activation of succinate/SUCNR1 pathway, while BHGZ regulates SDH activity to reduce the accumulation of succinate and inhibit the activation of SUCNR1 that is the underlying mechanism of its treatment of RA.

The Effect of Polyphenols on Hypercholesterolemia through Inhibiting the Transport and Expression of Niemann-Pick C1-Like 1

The Niemann-Pick C1-like 1 (NPC1L1) protein is a cholesterol transporter that is expressed in the small intestine. This report describes the discovery of NPC1L1, its transport properties, and the inhibitory effects of polyphenols on NPC1L1. NPC1L1 was identified in 2004 while searching for ezetimibe molecular targets. Excessive synthesis of cholesterol results in hyperlipidemia, which increases the amount of bile cholesterol excreted into the duodenum. The inhibition of NPC1L1 decreases blood cholesterol because food and bile cholesterol are also absorbed from NPC1L1 in the intestine. Some polyphenols, particularly luteolin, have been reported as NPC1L1-mediated anti-dyslipidemia constituents. Luteolin affects NPC1L1 through two mechanisms. Luteolin directly inhibits NPC1L1 by binding to it, which occurs in a short timeframe similar to that for ezetimibe. The other mechanism is the inhibition of NPC1L1 expression. Luteolin reduced the binding of Sterol-regulatory element-binding protein 2 (SREBP2) in the promoter region of the NPC1L1 gene and decreased mRNA levels of SREBP2 and hepatocyte nuclear factor 4α. These data suggest that luteolin decreases the expression of NPC1L1 through regulation of transcription factors. This review also explores the effect of other polyphenols on NPC1L1 and hypercholesterolemia.

Natural Products from Mediterranean Diet: From Anti-hyperlipidemic Agents to Dietary Epigenetic Modulators

Background:

Cardiovascular Diseases (CVD) are, currently, the major contributor to global mortality and will continue to dominate mortality rates in the future. Hyperlipidemia refers to the elevated levels of lipids and cholesterol in the blood, and is also identified as dyslipidemia, manifesting in the form of different disorders of lipoprotein metabolism. These abnormalities may lead to the development of atherosclerosis, which can lead to coronary artery disease and stroke. In recent years, there is a growing interest in the quest for alternative therapeutic treatments based on natural products, offering better recovery and the avoidance of side effects. Recent technological advances have further improved our understanding of the role of epigenetic mechanisms in hyperlipidemic disorders and dietary prevention strategies.

Objective:

This is a comprehensive overview of the anti-hyperlipidemic effects of plant extracts, vegetables, fruits and isolated compounds thereof, with a focus on natural products from the Mediterranean region as well as the possible epigenetic changes in gene expression or cardiometabolic signaling pathways.

Methods:

For the purpose of this study, we searched the PubMed, Scopus and Google Scholar databases for eligible articles and publications over the last five years. The keywords included: “hyperlipidemia”, “plant extract”, “herbs”, “natural products”, “vegetables”, “cholesterol” and others. We initially included all relevant articles referring to in vitro studies, animal studies, Randomized Controlled Trials (RCTs) and previous reviews.

Conclusion:

Many natural products found in the Mediterranean diet have been studied for the treatment of hyperlipidemia. The antihyperlipidemic effect seems to be dose and/or consumption frequency related, which highlights the fact that a healthy diet can only be effective in reversing disease markers if it is consistent and within the framework of a healthy lifestyle. Finally, epigenetic biomarkers are increasingly recognized as new lifestyle management tools to monitor a healthy dietary lifestyle for the prevention of hyperlipidaemic disorders and comorbidities to promote a healthy life.

Uptake of Manganese from the Manganese-Lysine Complex in Primary Chicken Intestinal Epithelial Cells

Simple Summary

Manganese (Mn) supplementation is especially necessary to avian species because the absorption of dietary Mn is relatively inefficient in birds. Recently, there has been increasing interest in the use of organic Mn to replace inorganic Mn as dietary Mn supplements in poultry. This study compared the uptake of Mn from Mn-lysine complex (MnLys) and MnSO₄ in the primary chicken intestinal epithelial cells when the Fe, N-ethylmaleimide (a transport system y⁺ inhibitor), or cycloheximide (a transport system b^0,+ activator) added in the culture medium. The results revealed that the uptake of Mn from the MnLys complex not only might be transported through the ionized Mn²⁺ pathway, but also appeared to be transported through the transport systems y⁺ and b^0,+ in the intestine of chickens.

Abstract

Organic manganese (Mn) sources can replace inorganic Mn as dietary Mn supplements in poultry. To compare the uptake of Mn from the Mn-lysine complex (MnLys) and MnSO₄, we first established the primary chicken intestinal epithelial cells (IECs) model and used it to determine Mn uptake. The MnLys increased the uptake of Mn compared to MnSO₄. The uptake of Mn decreased in the IECs with Fe addition in the medium regardless of the Mn sources. The MnLys decreased the Mn²⁺ efflux transporter ferroportin 1 (FPN1) mRNA level but did not influence the Mn²⁺ influx transporter divalent metal transporter 1 (DMT1) mRNA expression when compared to MnSO₄. The results above indicated that the increase of Mn accumulation for MnLys at least partly was due to the decrease of Mn efflux by reduced FPN1 expression. The addition of N-ethylmaleimide, an L-lysine transport system y⁺ inhibitor, decreased the uptake of Mn from MnLys but did not affect the uptake of Mn from MnSO₄. The cycloheximide, as an L-lysine transport system b^0,+ activator, increased the uptake of Mn from MnLys, whereas they did not influence the uptake of Mn from MnSO₄. The MnLys increased the system y⁺ members cationic amino acid transporter (CAT) 1 and CAT2, and system b^0,+ components rBAT and b^0,+AT mRNA expression when compared to MnSO₄. These results suggested that the uptake of MnLys complex might be transported by CAT1/2 and system b^0,+, which was different from the ionized Mn²⁺ uptake pathway. In conclusion, the uptake of Mn from MnLys complex not only might be uptake through the ionized Mn²⁺ pathway, but also appeared to be transported through the CAT1/2 and system b^0,+ in primary chicken IECs.

Effect of Nutrient and Micronutrient Intake on Chylomicron Production and Postprandial Lipemia

Postprandial lipemia, which is one of the main characteristics of the atherogenic dyslipidemia with fasting plasma hypertriglyceridemia, low high-density lipoprotein cholesterol and an increase of small and dense low-density lipoproteins is now considered a causal risk factor for atherosclerotic cardiovascular disease and all-cause mortality. Postprandial lipemia, which is mainly related to the increase in chylomicron production, is frequently elevated in individuals at high cardiovascular risk such as obese or overweight patients, type 2 diabetic patients and subjects with a metabolic syndrome who share an insulin resistant state. It is now well known that chylomicron production and thus postprandial lipemia is highly regulated by many factors such as endogenous factors: circulating factors such as hormones or free fatty acids, genetic variants, circadian rhythms, or exogenous factors: food components, dietary supplements and prescription drugs. In this review, we focused on the effect of nutrients, micronutrients and phytochemicals but also on food structure on chylomicron production and postprandial lipemia.

Antihyperglycemic activities of twig extract of indigenous cinnamon (Cinnamomum osmophloeum) on high-fat diet and streptozotocin-induced hyperglycemic rats

BACKGROUND

Cinnamomum osmophloeum (indigenous cinnamon) is an endemic species in Taiwan and its twigs contain abundant A-type proanthocyanidins. C. osmophloeum twig extracts (CoTEs) were found to have α-glucosidase and α-amylase inhibitory activities in vitro. The aim of this study is to further investigate the antihyperglycemic activity of CoTEs in hyperglycemic rats.

RESULTS

Hyperglycemic rats were divided into three groups and were treated orally with high-dosage CoTEs (HCO, 150 mg kg^-1 ), low-dosage CoTEs (LCO, 30 mg kg^-1 ) and positive control (PC, 30 mg kg^-1 pioglitazone). The HCO group showed improved glucose tolerance in an oral glucose tolerance test after 1 month of treatment, contributed by the inhibition of intestinal disaccharidases, amylase, and lipase. Compared with the PC group, both the HCO and LCO groups had decreased weight of visceral fats and lower atherogenic index; while their low-density lipoprotein-cholesterol, food intake, feed efficiency, and biochemical parameters remained unchanged compared with the NC group. Furthermore, the HCO group had decreased weight gain and the LCO group had decreased serum leptin level.

CONCLUSION

These results suggest that CoTE has potential antihyperglycemic activities for treating hyperglycemia without weight gain. © 2018 Society of Chemical Industry.

Anti-Atherosclerotic Effect of a Polyphenol-Rich Ingredient, Oleactiv®, in a Hypercholesterolemia-Induced Golden Syrian Hamster Model

The development of nutraceutical ingredients has risen as a nutritional solution for health prevention. This study evaluated the effects of Oleactiv®, an ingredient developed for the prevention of atherogenesis, in hypercholesterolemic hamsters. Oleactiv® is a polyphenol-rich ingredient obtained from artichoke, olive and grape extracts as part of fruit and vegetables commonly consumed within the Mediterranean diet. A total of 21 Golden Syrian hamsters were divided into three groups. The standard group (STD) was fed a normolipidemic diet for 12 weeks, while the control group (CTRL) and Oleactiv® goup (OLE) were fed a high-fat diet. After sacrifice, the aortic fatty streak area (AFSA), plasmatic total cholesterol (TC), high-density lipoproteins (HDL-C), non-HDL-C and triglycerides (TG), were assessed. The cholesterol efflux capacity (CEC) of hamster plasma was quantified using a radiolabeled technique in murine macrophages J774. OLE administration induced a significant reduction of AFSA (-69%, p < 0.0001). Hamsters of the OLE group showed a significant decrease of both non-HDL-C (-173 mmol/L, p < 0.05) and TG (-154 mmol/L, p < 0.05). Interestingly, OLE induced a significant increase of total CEC (+17,33%, p < 0,05). Oleactiv® supplementation prevented atheroma development and had positive effects on the lipid profile of hypercholesterolemic hamsters. The increased CEC underlines the anti-atherosclerotic mechanism at the root of the atheroma reduction observed.

Phytotherapy in the Management of Diabetes: A Review

Phytotherapy has long been a source of medicinal products and over the years there have been many attempts to use herbal medicines for the treatment of diabetes. Several medicinal plants and their preparations have been demonstrated to act at key points of glucidic metabolism. The most common mechanisms of action found include the inhibition of α-glucosidase and of AGE formation, the increase of GLUT-4 and PPARs expression and antioxidant activity. Despite the large amount of literature available, the actual clinical effectiveness of medicinal plants in controlling diabetes-related symptoms remains controversial and there is a crucial need for stronger evidence-based data. In this review, an overview of the medicinal plants, which use in the management of diabetes is supported by authoritative monographs, is provided. References to some species which are currently under increasing clinical investigation are also reported.

Linoleic acid, α-linolenic acid and enterolactone affect lipid oxidation and expression of lipid metabolism and antioxidant-related genes in hepatic tissue of dairy cows

Although beneficial effects have been attributed to PUFA supplementation in high-yielding dairy cows, diets rich in PUFA may also increase oxidative stress in tissues such as the liver. To fully exploit the health benefits of PUFA, we believe that the addition of natural antioxidants could help in preventing oxidative damage. Using an in vitro precision-cut liver slices (PCLS) tissue culture system, we investigated the effects of different linoleic acid (LA, n-6):α-linolenic acid (ALA, n-3) ratios (LA:ALA ratio of 4, LA:ALA ratio of 15 and LA:ALA ratio of 25) in the presence or absence of the antioxidant enterolactone (ENL) on (1) the mRNA abundance of genes with key roles in hepatic lipid metabolism, oxidative stress response and inflammatory processes, (2) oxidative damages to lipids and proteins and (3) superoxide dismutase activity in early-lactating dairy cows. The addition of LA and ALA to PCLS culture media increased oxidative damage to lipids as suggested by higher concentrations of thiobarbituric acid reactive substances and increased the expression of nuclear factor erythroid 2-related factor 2 target genes. The addition of ENL was effective in preventing lipid peroxidation caused by LA and ALA. Transcript abundance of sterol regulatory element-binding transcription factor 1 and its lipogenic target genes acetyl-CoA carboxylase α, fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD) was decreased with LA and ALA, whereas ENL decreased FASN and SCD gene expression. Our results show that addition of LA and ALA to PCLS culture media lowers hepatic lipogenic gene expression and increases oxidative damages to lipids. On the other hand, addition of ENL prevents oxidative damages provoked by these PUFA.

The Antidiabetic Mechanisms of Polyphenols Related to Increased Glucagon-Like Peptide-1 (GLP1) and Insulin Signaling

Type-2 diabetes mellitus (T2DM) is an endocrine disease related to impaired/absent insulin signaling. Dietary habits can either promote or mitigate the onset and severity of T2DM. Diets rich in fruits and vegetables have been correlated with a decreased incidence of T2DM, apparently due to their high polyphenol content. Polyphenols are compounds of plant origin with several documented bioactivities related to health promotion. The present review describes the antidiabetic effects of polyphenols, specifically related to the secretion and effects of insulin and glucagon-like peptide 1 (GLP1), an enteric hormone that stimulates postprandial insulin secretion. The evidence suggests that polyphenols from various sources stimulate L-cells to secrete GLP1, increase its half-life by inhibiting dipeptidyl peptidase-4 (DPP4), stimulate β-cells to secrete insulin and stimulate the peripheral response to insulin, increasing the overall effects of the GLP1-insulin axis. The glucose-lowering potential of polyphenols has been evidenced in various acute and chronic models of healthy and diabetic organisms. Some polyphenols appear to exert their effects similarly to pharmaceutical antidiabetics; thus, rigorous clinical trials are needed to fully validate this claim. The broad diversity of polyphenols has not allowed for entirely describing their mechanisms of action, but the evidence advocates for their regular consumption.

C-reactive protein levels are inversely correlated with the apolipoprotein B-48-containing triglyceride-rich lipoprotein production rate in insulin resistant men

The pro-inflammatory state and elevated plasma levels of post-prandial triglycerides (TG) are associated with increased cardiovascular disease risk. Recent studies suggested that the increase in the production rate of post-prandial lipoproteins observed in patients with insulin resistance (IR) may be caused, at least in part, by the dysregulation of intestinal insulin sensitivity triggered by inflammation.

OBJECTIVE

The objective of the present study was to evaluate the association between IR, plasma C-reactive protein (CRP) levels and the kinetics of TG-rich lipoprotein (TRL) containing apolipoprotein (apo) B-48 in a large sample of insulin sensitive (IS) and IR men.

METHODS

The in vivo kinetics of TRL apoB-48 were measured in 151 men following a primed-constant infusion of l-[5,5,5-D₃]leucine. IR subjects (n=91) were characterized by fasting TG levels ≥1.5mmol/L and an index of homeostasis model assessment of IR (HOMA-IR)≥2.5 or type 2 diabetes, while IS subjects (n=24) were characterized by an HOMA-IR index <2.5 and TG levels <1.5mmol/L.

RESULTS

IR subjects had higher TRL apoB-48 production rate (+202%; P<0.0001) and CRP levels (+51%; P=0.01) than IS subjects. TRL apoB-48 production rate and CRP levels were inversely correlated in IR subjects (r=-0.32; P=0.002). IR subjects with CRP levels above the median (2.20mg/L) had lower TRL apoB-48 production rate than IR subjects with CRP levels below the median (Δ=-24%; P<0.05).

CONCLUSION

Our results confirm that IR is associated with increased TRL apoB-48 secretion and suggest that a higher inflammatory status is associated with decreased TRL apoB-48 secretion among IR subjects.

The Gastrointestinal Tract as a Key Target Organ for the Health-Promoting Effects of Dietary Proanthocyanidins

Proanthocyanidins (PACs) are polymers of flavan-3-ols abundant in many vegetable foods and beverages widely consumed in the human diet. There is increasing evidence supporting the beneficial impact of dietary PACs in the prevention and nutritional management of non-communicable chronic diseases. It is considered that PACs with a degree of polymerization >3 remain unabsorbed in the gastrointestinal (GI) tract and accumulate in the colonic lumen. Accordingly, the GI tract may be considered as a key organ for the healthy-promoting effects of dietary PACs. PACs form non-specific complexes with salivary proteins in mouth, originating the sensation of astringency, and with dietary proteins, pancreatic enzymes, and nutrient transporters in the intestinal lumen, decreasing the digestion and absorption of carbohydrates, proteins, and lipids. They also exert antimicrobial activities, interfering with cariogenic or ulcerogenic pathogens in the mouth (Streptococcus mutans) and stomach (Helicobacter pylori), respectively. Through their antioxidant and antiinflammatory properties, PACs decrease inflammatory processes in animal model of gastric and colonic inflammation. Interestingly, they exert prebiotic activities, stimulating the growth of Lactobacillus spp. and Bifidobacterium spp. as well as some butyrate-producing bacteria in the colon. Finally, PACs are also metabolized by the gut microbiota, producing metabolites, mainly aromatic acids and valerolactones, which accumulate in the colon and/or are absorbed into the bloodstream. Accordingly, these compounds could display biological activities on the colonic epithelium or in extra-intestinal tissues and, therefore, contribute to part of the beneficial effects of dietary PACs.

Do Cinnamon Supplements Have a Role in Glycemic Control in Type 2 Diabetes? A Narrative Review

Cinnamon (Cinnamomum sp) has been suggested to help patients with type 2 diabetes mellitus (T2DM) achieve better glycemic control, although conclusions from meta-analyses are mixed. To evaluate whether the use of cinnamon dietary supplements by adults with T2DM had clinically meaningful effects on glycemic control, as measured by changes in fasting plasma glucose (FPG) or hemoglobin A1c (HbA1c), a comprehensive PubMed literature search was performed. Eleven randomized controlled trials were identified that met our inclusion criteria that enrolled 694 adults with T2DM receiving hypoglycemic medications or not. In 10 of the studies, participants continued to take their hypoglycemic medications during the cinnamon intervention period. Studies ranged from 4 to 16 weeks in duration; seven studies were double-blind. Cinnamon doses ranged from 120 to 6,000 mg/day. The species of cinnamon used varied: seven used Cinnamomum cassia or Cinnamomum aromaticum, one used Cinnamomum zeylanicum, and three did not disclose the species. Because of the heterogeneity of the studies, a meta-analysis was not conducted. All 11 of the studies reported some reductions in FPG during the cinnamon intervention, and of the studies measuring HbA1c very modest decreases were also apparent with cinnamon, whereas changes in the placebo groups were minimal. However, only four studies achieved the American Diabetes Association treatment goals (FPG <7.2 mmol/L [130 mg/dL] and/or HbAlc <7.0). We conclude that cinnamon supplements added to standard hypoglycemic medications and other lifestyle therapies had modest effects on FPG and HbA1c. Until larger and more rigorous studies are available, registered dietitian nutritionists and other health care professionals should recommend that patients continue to follow existing recommendations of authoritative bodies for diet, lifestyle changes, and hypoglycemic drugs.

Cell Systems to Investigate the Impact of Polyphenols on Cardiovascular Health

Polyphenols are a diverse group of micronutrients from plant origin that may serve as antioxidants and that contribute to human health in general. More specifically, many research groups have investigated their protective effect against cardiovascular diseases in several animal studies and human trials. Yet, because of the excessive processing of the polyphenol structure by human cells and the residing intestinal microbial community, which results in a large variability between the test subjects, the exact mechanisms of their protective effects are still under investigation. To this end, simplified cell culture systems have been used to decrease the inter-individual variability in mechanistic studies. In this review, we will discuss the different cell culture models that have been used so far for polyphenol research in the context of cardiovascular diseases. We will also review the current trends in cell culture research, including co-culture methodologies. Finally, we will discuss the potential of these advanced models to screen for cardiovascular effects of the large pool of bioactive polyphenols present in foods and their metabolites.

Effect of Cinnamon Tea on Postprandial Glucose Concentration

Glycaemic control, in particular at postprandial period, has a key role in prevention of different diseases, including diabetes and cardiovascular events. Previous studies suggest that postprandial high blood glucose levels (BGL) can lead to an oxidative stress status, which is associated with metabolic alterations. Cinnamon powder has demonstrated a beneficial effect on postprandial glucose homeostasis in animals and human models. The purpose of this study is to investigate the effect of cinnamon tea (C. burmannii) on postprandial capillary blood glucose level on nondiabetic adults. Participants were given oral glucose tolerance test either with or without cinnamon tea in a randomized clinical trial. The data revealed that cinnamon tea administration slightly decreased postprandial BGL. Cinnamon tea ingestion also results in a significantly lower postprandial maximum glucose concentration and variation of maximum glucose concentration (p < 0.05). Chemical analysis showed that cinnamon tea has a high antioxidant capacity, which may be due to its polyphenol content. The present study provides evidence that cinnamon tea, obtained from C. burmannii, could be beneficial for controlling glucose metabolism in nondiabetic adults during postprandial period.

Prevention of oxidative stress, inflammation and mitochondrial dysfunction in the intestine by different cranberry phenolic fractions

Cranberry fruit has been reported to have high antioxidant effectiveness that is potentially linked to its richness in diversified polyphenolic content. The aim of the present study was to determine the role of cranberry polyphenolic fractions in oxidative stress (OxS), inflammation and mitochondrial functions using intestinal Caco-2/15 cells. The combination of HPLC and UltraPerformance LC®-tandem quadrupole (UPLC-TQD) techniques allowed us to characterize the profile of low, medium and high molecular mass polyphenolic compounds in cranberry extracts. The medium molecular mass fraction was enriched with flavonoids and procyanidin dimers whereas procyanidin oligomers (DP > 4) were the dominant class of polyphenols in the high molecular mass fraction. Pre-incubation of Caco-2/15 cells with these cranberry extracts prevented iron/ascorbate-mediated lipid peroxidation and counteracted lipopolysaccharide-mediated inflammation as evidenced by the decrease in pro-inflammatory cytokines (TNF-α and interleukin-6), cyclo-oxygenase-2 and prostaglandin E2. Cranberry polyphenols (CP) fractions limited both nuclear factor κB activation and Nrf2 down-regulation. Consistently, cranberry procyanidins alleviated OxS-dependent mitochondrial dysfunctions as shown by the rise in ATP production and the up-regulation of Bcl-2, as well as the decline of protein expression of cytochrome c and apoptotic-inducing factor. These mitochondrial effects were associated with a significant stimulation of peroxisome-proliferator-activated receptor γ co-activator-1-α, a central inducing factor of mitochondrial biogenesis and transcriptional co-activator of numerous downstream mediators. Finally, cranberry procyanidins forestalled the effect of iron/ascorbate on the protein expression of mitochondrial transcription factors (mtTFA, mtTFB1, mtTFB2). Our findings provide evidence for the capacity of CP to reduce intestinal OxS and inflammation while improving mitochondrial dysfunction.

Cinnamon polyphenols regulate S100β, sirtuins, and neuroactive proteins in rat C6 glioma cells

OBJECTIVE

Increasing evidence suggests that cinnamon has many health benefits when used in herbal medicine and as a dietary ingredient. The aim of this study was to investigate the effects of an aqueous extract of cinnamon, high in type A polyphenols, on molecular targets in rat C6 glioma cells that underlie their protective effects.

METHODS

C6 rat glioma cells were seeded in 35-mm culture dishes or six-well plates, then were incubated with cinnamon polyphenols at doses of 10 and 20 μg/mL for 24 h. The targeting protein expression, secretion, and phosphorylation were evaluated by immunoprecitation/immunoblotting and immunofluorescence imaging.

RESULTS

Cinnamon polyphenols significantly enhanced secretion of S100β, a Ca(2+)-binding protein, and increased intracellular S100β expression after 24 h of incubation, in rat C6 glioma cells. Cinnamon polyphenols also enhanced protein levels of sirtuin 1, 2, and 3, deacetylases important in cell survival, and the tumor suppressor protein, p53, and inhibited the inflammatory factors, tumor necrosis factor alpha, and phospho-p65, a subunit of nuclear factor-κβ. Cinnamon polyphenols also up-regulated levels of phospho-p38, extracellular signal-regulated protein and mitogen-activated protein and kinase-activated protein kinases that may be important for prosurvival functions.

CONCLUSION

Our results indicate that the effects of cinnamon polyphenols on upregulating prosurvival proteins, activating mitogen-activated protein kinase pathways, and decreasing proinflammatory cytokines may contribute to their neuroprotective effects.

Herbal therapies for type 2 diabetes mellitus: chemistry, biology, and potential application of selected plants and compounds

Diabetes mellitus has been recognized since antiquity. It currently affects as many as 285 million people worldwide and results in heavy personal and national economic burdens. Considerable progress has been made in orthodox antidiabetic drugs. However, new remedies are still in great demand because of the limited efficacy and undesirable side effects of current orthodox drugs. Nature is an extraordinary source of antidiabetic medicines. To date, more than 1200 flowering plants have been claimed to have antidiabetic properties. Among them, one-third have been scientifically studied and documented in around 460 publications. In this review, we select and discuss blood glucose-lowering medicinal herbs that have the ability to modulate one or more of the pathways that regulate insulin resistance, β-cell function, GLP-1 homeostasis, and glucose (re)absorption. Emphasis is placed on phytochemistry, anti-diabetic bioactivities, and likely mechanism(s). Recent progress in the understanding of the biological actions, mechanisms, and therapeutic potential of compounds and extracts of plant origin in type 2 diabetes is summarized. This review provides a source of up-to-date information for further basic and clinical research into herbal therapy for type 2 diabetes. Emerging views on therapeutic strategies for type 2 diabetes are also discussed.

Herbal therapies for type 2 diabetes mellitus: chemistry, biology, and potential application of selected plants and compounds

Background:

Diabetes mellitus, becoming the third killer of mankind after cancer and cardiovascular diseases, is one of the most challenging diseases facing health care professionals today. That is why; there has been a growing interest in the therapeutic use of natural products for diabetes, especially those derived from plants.

Aim:

To evaluate the anti-diabetic activity together with the accompanying biological effects of the fractions and the new natural compounds of Hyphaene thebaica (HT) epicarp.

Materials and Methods:

500 g of coarsely powdered of (HT) fruits epicarp were extracted by acetone. The acetone crude extract was fractionated with methanol and ethyl acetate leaving a residual water-soluble fraction WF. The anti-diabetic effects of the WF and one of its compounds of the acetone extract of the (HT) epicarp were investigated in this study using 40 adult male rats.

Results:

Phytochemical investigation of active WF revealed the presence of ten different flavonoids, among which two new natural compounds luteolin 7-O-[6”-O-α-Lrhamnopyranosyl]-β-D-galactopyranoside 3 and chrysoeriol 7-O-β-D-galactopyranosyl(1→2)-α-L-arabinofuranoside 5 were isolated. Supplementation of the WF improved glucose and insulin tolerance and significantly lowered blood glycosylated hemoglobin levels. On the other hand, compound 5 significantly reduced AST and ALT levels of liver, respectively. Likewise, the kidney functions were improved for both WF and compound 5, whereby both urea and creatinine levels in serum were highly significant

Conclusion:

The results justify the use of WF and compound 5 of the (HT) epicarp as anti-diabetic agent, taking into consideration that the contents of WF were mainly flavonoids