Ferulic Acid on Glucose Dysregulation, Dyslipidemia, and Inflammation in Diet-Induced Obese Rats: An Integrated Study

SIRT1/AMPK-mediated pathway: Ferulic acid from sugar beet pulp mitigating obesity-induced diabetes-linked complications and improving metabolic health

Obesity-induced type 2 diabetes (T2D) increases the risk of metabolic syndrome due to the high calorie intake. The role of sugar beet pulp (SBP) in T2D and the mechanism of its action remain unclear, though it is abundant in phenolics and has antioxidant activity. In this study, we isolated and purified ferulic acid from SBP, referred to as SBP-E, and studied the underlying molecular mechanisms in the regulation of glucose and lipid metabolism developing high glucose/high fat diet-induced diabetic models in vitro and in vivo. SBP-E showed no cytotoxicity and reduced the oxidative stress by increasing glutathione (GSH) in human liver (HepG2) and rat skeletal muscle (L6) cells. It also decreased body weight gain, food intake, fasting blood glucose levels (FBGL), glucose intolerance, hepatic steatosis, and lipid accumulation. Additionally, SBP-E decreased the oxidative stress and improved the antioxidant enzyme levels in high-fat diet (HFD)-induced T2D mice. Further, SBP-E reduced plasma and liver advanced glycation end products (AGEs), malondialdehyde (MDA), and pro-inflammatory cytokines, and increased anti-inflammatory cytokines in HFD-fed mice. Importantly, SBP-E significantly elevated AMPK, glucose transporter, SIRT1 activity, and Nrf2 expression and decreased ACC expression and SREBP1 levels in diabetic models. Collectively, our study results suggest that SBP-E treatment can improve obesity-induced T2D by regulating glucose and lipid metabolism via SIRT1/AMPK signalling and the AMPK/SREBP1/ACC1 pathway.

Dietary Ferulic Acid Increases Endurance Capacity by Promoting Skeletal Muscle Oxidative Phenotype, Mitochondrial Function, and Antioxidant Capacity

SCOPE

Endurance capacity is essential for endurance athletes' achievement and individuals' health. Nutritional supplements are a proven way to enhance endurance capacity. Previous studies have shown that ferulic acid (FA) enhances endurance capacity, but the underlying mechanism is unclear. The study is aimed to investigate the mechanism by which FA increases endurance capacity.

METHODS AND RESULTS

Forty mice are divided into control and 0.5% FA-supplemented groups, and an exhaustive swimming test demonstrates increased endurance capacity with FA supplementation. This study investigates the underlying mechanism for this effect of FA. Firstly, RT-PCR and western blot analysis find that FA increases the transformation from fast to slow muscle fiber. Additionally, adenosine triphosphate concentration, metabolic enzyme activity, and mitochondrial DNA analysis find that FA increases mitochondrial biogenesis and activates nuclear factor erythroid 2-related factor (NRF)1 signaling pathway in muscle. Besides, through antioxidant capacity analysis, this study finds that FA activates NRF2 signaling pathway and improves the antioxidant capacity in muscle. Moreover, inhibiting NRF2 eliminates FA's effect on muscle fiber transformation in C2C12 cells.

CONCLUSION

Our results suggest that FA increases endurance capacity by promoting skeletal muscle oxidative phenotype, mitochondrial function, and antioxidant capacity, which may be related to the NRF1 and NRF2 signaling pathways.

Attenuation of fluoride-induced hepatorenal oxidative stress by ferulic acid in vivo: An approach with in-silico analysis and interaction informatics of ferulic acid

BACKGROUND

Chronic fluoride toxicity induces oxidative strain and lipid peroxidation and imparts deleterious effects on human metabolic organs.

AIM

The present study aimed to expose the defensive impact of ferulic acid against sodium fluoride (NaF) induced hepatorenal dysfunction at the biochemical and antioxidative systems.

METHODS

In-vivo. Rats were arbitrarily separated into five groups as control, sodium fluoride-treated (200 ppm kg ^-1), vitamin C -as a positive control, and FA co-administered groups with 10 mg kg ^-1 and 20 mg kg ^-1 body weight for 56 days. In the present investigation, we measured antioxidant enzymes, superoxide dismutase, catalase, and lactate dehydrogenase by electrozymographic and spectrophotometric methods. Biochemical assessment of TBARS, conjugated diene, and different serum biomarkers was done for liver and kidney functionality tests. In-silico. An in-silico study was conducted through a molecular docking experiment to evaluate the binding potentiality of FA by employing AutoDock Vina [version 1.5.6] to overcome the abnormality in the activities of catalase, and superoxide dismutase in NaF promoted toxicity of hepatorenal system. In-vitro. An in vitro biochemical experiment was conducted to support the in-silico study.

RESULTS

Superoxide dismutase and catalase were decreased in the intoxicated rat. Ferulic acid (FA) as an antioxidant remarkably defended the NaF-mediated deterioration of the antioxidative status in the hepatorenal system, lowering lipid peroxidation products, malondialdehyde, and conjugated diene. Serum biomarkers, ALT, AST, ALP, urea, and creatinine increased in the intoxicated group than in control. Ferulic acid significantly neutralized the ill effects of NaF on serum lipid profile. In-silico analysis hypothesized the strong interaction of FA with the active side of catalase and superoxide dismutase that prevented the binding of NaF at the active site of these mentioned enzymes and this was further validated by in-vitro assay.

CONCLUSION

However, FA modulates free radical generation and protected these metabolic organs against sodium fluoride-induced injury.

Revisiting the high-fat diet/low streptozotocin prediabetic rat model: A bioanalytical adjustment

Insulin resistance (IR) is the main feature of prediabetes (PD), which ultimately leads to diabetes. High-dose streptozotocin-treated rodents often show irreversible β-cell mass loss and function, leaving the premorbid diabetic state (PD/IR) unnoticed. This study aimed to re-evaluate the synergistic/independent effect of a sub-chronic consumption (1-5 weeks) of a high-fat diet (60% gross energy from fat, 3.8 kcal.g^-1) with [PD/IR-2 (week 2) to PD/IR-5 week five)] or without [HFD-5 (week five)] a single intraperitoneal dose (35 mg.kg^-1) of streptozotocin in Wistar rats. Bioassay performance and clinical/histological features suggesting PD/IR or diabetes, were documented weekly and compared to standard chow-fed (3.5 kcal.g^-1) rats (healthy controls, HC). PD/IR1-5 (fed with HFD for 1 to 5 weeks plus a single dose of streptozotocin) and HFD-5 (just fed with HFD for 5 weeks) groups reduced their food intake yet gained more body weight than HC. Groups exhibited hyperglycemia, dyslipidemia, and impaired glucose tolerance in decreasing order as follows: PD/IR-5, PD/IR-4, HFD-5, PD/IR-2-3, and HC. Histological disturbances in the pancreas, Soleus muscle, and liver were mostly observed in HFD-5 and PD/IR4-5 groups. HFD administration for 4 weeks white a single moderate dose of streptozotocin four days before sacrifice, leads to a convenient PD/IR rat model.

Ferulic acid supplementation for 40 days in hair ewe lambs experiencing seasonal heat stress: short-term effects on physiological responses, growth, metabolism, and hematological profile

Free ferulic acid (FA) is a natural compound with antioxidant properties which mitigates the negative effects of cold stress in sheep; however, its impact on thermoregulatory responses in heat-stressed sheep has not been defined. The objective was to evaluate the effects of FA supplementation on physiological responses, serum analyte concentrations, and the hematological profile of heat-stressed hair ewe lambs. Twenty-two Dorper × Katahdin ewe lambs (initial body weight = 23.5 ± 2.8 kg and age = 4 months) were housed in individual pens for 40 days and assigned under a randomized complete block design to the following treatments (n = 11): basal diet with 0 (control) or 250 mg of FA/kg of feed. The FA × sampling day interaction only affected serum concentration of some metabolic hormones; particularly on day 20 of the trial, FA increased (P < 0.01) insulins and the insulin to glucose ratio while decreased (P = 0.05) thyroxine. Overall, supplemental FA did not affect rectal temperature, respiratory rate, most body surface temperatures, feedlot performance, and serum concentrations of metabolites, electrolytes, triiodothyronine, and cortisol. In addition, FA only tended to decrease (P ≥ 0.09) erythrocyte count and plaquetocrit and to increase (P = 0.08) mean corpuscular volume. In conclusion, FA supplementation did not improve the growth nor thermoregulatory capacity of heat-stressed hair ewe lambs. Still, it partially modulated the metabolism to reinforce some energetic adaptive mechanisms when the ambient temperature was ≥ 35 °C.

Protective Effects of Ferulic Acid on Metabolic Syndrome: A Comprehensive Review

Metabolic syndrome (MetS) is a complex disease in which protein, fat, carbohydrates and other substances are metabolized in a disorderly way. Ferulic acid (FA) is a phenolic acid found in many vegetables, fruits, cereals and Chinese herbs that has a strong effect on ameliorating MetS. However, no review has summarized the mechanisms of FA in treating MetS. This review collected articles related to the effects of FA on ameliorating the common symptoms of MetS, such as diabetes, hyperlipidemia, hypertension and obesity, from different sources involving Web of Science, PubMed and Google Scholar, etc. This review summarizes the potential mechanisms of FA in improving various metabolic disorders according to the collected articles. FA ameliorates diabetes via the inhibition of the expressions of PEPCK, G6Pase and GP, the upregulation of the expressions of GK and GS, and the activation of the PI3K/Akt/GLUT4 signaling pathway. The decrease of blood pressure is related to the endothelial function of the aortas and RAAS. The improvement of the lipid spectrum is mediated via the suppression of the HMG-Co A reductase, by promoting the ACSL1 expression and by the regulation of the factors associated with lipid metabolism. Furthermore, FA inhibits obesity by upregulating the MEK/ERK pathway, the MAPK pathway and the AMPK signaling pathway and by inhibiting SREBP-1 expression. This review can be helpful for the development of FA as an appreciable agent for MetS treatment.

Ferulic acid improves intestinal barrier function through altering gut microbiota composition in high-fat diet-induced mice

PURPOSE

A high-fat diet (HFD) induces gut microbiota (GM) disorders, leading to intestinal barrier dysfunction and inflammation. Ferulic acid (FA) has shown anti-obesity effects, e.g., reducing body weight and food intake. However, the mechanism linking the anti-obesity effects of FA and GM modulation remains obscure. The present study aimed to clarify the mechanism underlying the anti-obesity effects of FA and modulation of the GM.

METHODS

C57BL/6 J mice were fed by a low-fat diet (LFD) and HFD with or without FA at a dose of 100 mg/kg of body weight by oral gavage for 12 weeks. Using high-throughput sequencing, gas chromatography, real-time fluorescence quantitative PCR and immunohistochemical staining, the attenuation of obesity by FA were assessed via intestinal barrier integrity, inflammation, and the GM.

RESULTS

FA reduced weight gain, improved HFD-induced GM imbalance, significantly enhanced intestinal short-chain fatty acid (SCFA)-producing bacteria (e.g., Olsenella, Eisenbergiella, Dubosiella, Clostridiales_unclassified, and Faecalibaculum) along with SCFA accumulation and its receptors' expression, decreased endotoxin-producing bacteria or obesity-related bacterial genera, and serum endotoxin (lipopolysaccharides), and inhibited the colonic TLR4/NF-κB pathway. Thus, FA can mitigate colonic barrier dysfunction and intestinal inflammation, induce the production of SCFAs and inhibit endotoxins by modulating the GM.

CONCLUSION

These results indicate that enhancement of intestinal barrier by altering the GM may be an anti-obesity target of FA and that FA can be used as a functional compound with great developmental values.

HPLC-DAD assay of phenols profile in Antennaria dioica (L.) Gaertn

Antennaria dioica (Asteraceae family) – is a perennial herb, commonly found in dry grasslands and sandy or stony places from Eurasian areas. It is known in traditional medicine as antioxidant, diuretic, choleretic and anti-inflammatory remedy. This species should be reconsidered as possible sources of phenols, mainly flavonoids and hydroxycinnamic acids. Thus, the aim of this study was to validate a chromatographic method for detection of phenols and their identification in A. dioica herb. HPLC-DAD method was evaluated in terms of linearity, precision, repeatability, accuracy, LOD and LOQ. The calibration curves of thirteen reference substances were linear (R2 &gt; 0.99) over the range of 5–400 µg/mL, the LODs and the LOQs were in the range of 0.1–0.3 µg/mL and 0.2–1.0 µg/mL, respectively. During HPLC-DAD assay two flavones – luteolin, apigenin; flavonol – quercetin and three its glycosides – rutin, hyperoside and isoquercitrin; coumarins: coumarin and umbelliferone; five hydroxycinnamic acids – chlorogenic, caffeic, p-coumaric, trans-ferulic and rosmarinic were identified in A. dioica herb. This phytochemical study of A. dioica confirms that this plant material is a rich source of phenolic compounds.

Effects of ferulic acid on the growth performance, antioxidant capacity, and intestinal development of piglets with intrauterine growth retardation

Neonates with intrauterine growth retardation (IUGR) are prone to suffer from delayed postnatal growth and development during the early stages of life. Ferulic acid (FA) is a phenolic compound that is abundantly present in fruits and vegetables and has various health benefits. Hence, we explored whether FA supplementation could favorably affect the growth performance, antioxidant capacity, and intestinal development of piglets with IUGR. In total, eight normal-birth-weight (NBW) piglets and 16 piglets with IUGR (age, 7 d) were assigned to be fed either basic formula milk (NBW and IUGR groups, respectively) or basic formula milk supplemented with 100 mg/kg FA (IUGR + FA group) for 21 d. At necropsy, the serum and intestinal tissues were collected. FA supplementation increased (P < 0.05) the feed conversion ratio and serum total superoxide dismutase and catalase activities in piglets with IUGR. Moreover, FA supplementation elevated (P < 0.05) the duodenal lactase and maltase activities, jejunal villus height and jejunal maltase activity but reduced (P < 0.05) the duodenal crypt depth and duodenal and jejunal cell apoptosis, cleaved cysteinyl aspartic acid protease-3 (caspase-3) content and cleaved caspase-9 content in piglets with IUGR. In summary, FA supplementation could elevate antioxidant capacity and facilitate intestinal development, thus resulting in increased feed efficiency in piglets with IUGR.

Jieduquyuziyin Prescription alleviates hepatic gluconeogenesis via PI3K/Akt/PGC-1α pathway in glucocorticoid-induced MRL/lpr mice

ETHNOPHARMACOLOGICAL RELEVANCE

Jieduquyuziyin prescription (JP) is a traditional Chinese medicine (TCM) formula. According to both TCM theory and more than a decade of clinical practice, JP has been testified to be effective for systemic lupus erythematosus (SLE) treatment as an approved hospital prescription in China.

AIM OF THE STUDY

To determine the effect of JP on the treatment of SLE by glucocorticoid (GC) and to further examine the molecular mechanisms.

MATERIALS AND METHODS

We conducted in vivo experiments to estimate the effect of JP on hepatic gluconeogenesis in MRL/lpr mice treated with GC. Additionally, isoproterenol (ISO) induced hepatic gluconeogenesis model and GC-treated MRL/lpr mouse hepatocytes were carried out in vitro experiments to verify the effect of JP on gluconeogenesis.

RESULTS

The results showed that JP combined with GC could effectively alleviate the lupus symptoms in MRL/lpr mice and improve the pathological changes of the kidney and liver. And the combination of JP reduced the side effects caused by GC, which was related to the inhibition of GC-induced hepatic gluconeogenesis in MRL/lpr mice. Specifically, JP up-regulated the expression of glucocorticoid receptor (GR) α, phosphoinositide-3-kinase (PI3K) and Akt restrained by GC to reduce the production of forkhead box O1 (FoxO1), peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α), and the gluconeogenic genes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). In vivo, the use of JP either alone or with GC could reduce spleen enlargement, high levels of serum antibodies, aggravated urine protein and renal pathological damage in MRL/lpr mice. Furthermore, the glucose content was reduced in the liver of MRL/lpr mice treated with JP, and the liver damage and steatosis were also alleviated. In vitro, the expressions of PI3K and Akt increased and the expressions of FoxO1, PGC-1α, PEPCK and G6Pase decreased after JP treatment in ISO-treated hepatocytes. Compared with MRL/MP mice, we found that JP could significantly inhibit the expression of gluconeogenesis in the hepatocytes of MRL/lpr mice induced by GC to a greater extent.

CONCLUSIONS

The therapeutic effect of JP on GC-induced is likely related to hepatic gluconeogenesis, which provides a new perspective to reveal the positive role of JP in SLE.

The Use of Bioactive Compounds in Hyperglycemia- and Amyloid Fibrils-Induced Toxicity in Type 2 Diabetes and Alzheimer’s Disease

It has become increasingly apparent that defective insulin signaling may increase the risk for developing Alzheimer’s disease (AD), influence neurodegeneration through promotion of amyloid formation or by increasing inflammatory responses to intraneuronal β-amyloid. Recent work has demonstrated that hyperglycemia is linked to cognitive decline, with elevated levels of glucose causing oxidative stress in vulnerable tissues such as the brain. The ability of β-amyloid peptide to form β-sheet-rich aggregates and induce apoptosis has made amyloid fibrils a leading target for the development of novel pharmacotherapies used in managing and treatment of neuropathological conditions such as AD-related cognitive decline. Additionally, deposits of β-sheets folded amylin, a glucose homeostasis regulator, are also present in diabetic patients. Thus, therapeutic compounds capable of reducing intracellular protein aggregation in models of neurodegenerative disorders may prove useful in ameliorating type 2 diabetes mellitus symptoms. Furthermore, both diabetes and neurodegenerative conditions, such as AD, are characterized by chronic inflammatory responses accompanied by the presence of dysregulated inflammatory biomarkers. This review presents current evidence describing the role of various small bioactive molecules known to ameliorate amyloidosis and subsequent effects in prevention and development of diabetes and AD. It also highlights the potential efficacy of peptide–drug conjugates capable of targeting intracellular targets.

Impact of Food-Derived Bioactive Compounds on Intestinal Immunity

The gastrointestinal system is responsible for the digestion and the absorption of nutrients. At the same time, it is essentially involved in the maintenance of immune homeostasis. The strongest antigen contact in an organism takes place in the digestive system showing the importance of a host to develop mechanisms allowing to discriminate between harmful and harmless antigens. An efficient intestinal barrier and the presence of a large and complex part of the immune system in the gut support the host to implement this task. The continuous ingestion of harmless antigens via the diet requires an efficient immune response to reliably identify them as safe. However, in some cases the immune system accidentally identifies harmless antigens as dangerous leading to various diseases such as celiac disease, inflammatory bowel diseases and allergies. It has been shown that the intestinal immune function can be affected by bioactive compounds derived from the diet. The present review provides an overview on the mucosal immune reactions in the gut and how bioactive food ingredients including secondary plant metabolites and probiotics mediate its health promoting effects with regard to the intestinal immune homeostasis.

A Review of the Health Protective Effects of Phenolic Acids against a Range of Severe Pathologic Conditions (Including Coronavirus-Based Infections)

Phenolic acids comprise a class of phytochemical compounds that can be extracted from various plant sources and are well known for their antioxidant and anti-inflammatory properties. A few of the most common naturally occurring phenolic acids (i.e., caffeic, carnosic, ferulic, gallic, p-coumaric, rosmarinic, vanillic) have been identified as ingredients of edible botanicals (thyme, oregano, rosemary, sage, mint, etc.). Over the last decade, clinical research has focused on a number of in vitro (in human cells) and in vivo (animal) studies aimed at exploring the health protective effects of phenolic acids against the most severe human diseases. In this review paper, the authors first report on the main structural features of phenolic acids, their most important natural sources and their extraction techniques. Subsequently, the main target of this analysis is to provide an overview of the most recent clinical studies on phenolic acids that investigate their health effects against a range of severe pathologic conditions (e.g., cancer, cardiovascular diseases, hepatotoxicity, neurotoxicity, and viral infections—including coronaviruses-based ones).

Degradation Products of Complex Arabinoxylans by Bacteroides intestinalis Enhance the Host Immune Response

Bacteroides spp. of the human colonic microbiome degrade complex arabinoxylans from dietary fiber and release ferulic acid. Several studies have demonstrated the beneficial effects of ferulic acid. Here, we hypothesized that ferulic acid or the ferulic acid-rich culture supernatant of Bacteroides intestinalis, cultured in the presence of complex arabinoxylans, enhances the immune response. Ferulic acid and the culture supernatant of bacteria cultured in the presence of insoluble arabinoxylans significantly decreased the expression of tumor necrosis factor-α and increased the expression of interleukin-10 and transforming growth factor β1 from activated dendritic cells compared to controls. The number of granulocytes in mesenteric lymph nodes, the number of spleen monocytes/granulocytes, and interleukin-2 and interleukin-12 plasma levels were significantly increased in mice treated with ferulic acid or the culture supernatant of bacteria cultured with insoluble arabinoxylans. Ferulic acid or the culture supernatant of bacteria cultured with insoluble arabinoxylans increased the expression of interleukin-12, interferon-α, and interferon-β in intestinal epithelial cell lines. This study shows that ferulic acid or the ferulic acid-rich culture supernatant of the colonic bacterium Bacteroides intestinalis, cultured with insoluble arabinoxylans, exerts anti-inflammatory activity in dendritic cells under inflammatory conditions and enhances the Th1-type immune response under physiological conditions in mice.

Amaranthus spinosus Attenuated Obesity-Induced Metabolic Disorders in High-Carbohydrate-High-Fat Diet-Fed Obese Rats

Amaranthus spinosus is a common vegetable of Bangladesh and well-known for its ethnomedicinal uses. In this study, we have evaluated the ability of powdered supplementation, methanol extract, and aqueous extract of A. spinosus in attenuating in high-carbohydrate-high-fat (HCHF) diet-induced obesity and associated metabolic disorders in female obese rates. Several parameters have been analyzed in this study including body weight, organ weight, fat deposition, glycemic status, lipid levels, hepatic and renal biomarkers, hepatic antioxidant status, and hepatosteatosis. All three samples of A. spinosus significantly reduced weight gain, organ weight, and abdominal fat deposition. Improved glucose tolerance and lipid parameters were seen in obese rats administered with A. spinosus powder, methanol extract, and aqueous extract. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and creatine kinase levels were normalized by the test samples. A. spinosus boosted hepatic antioxidant levels including reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Histopathology of liver tissue revealed increased fat infiltration and higher steatosis score in HCHF diet-fed obese rats which was brought down by A. spinosus. Analyzing all the results it can be concluded that this medicinal herb is beneficial in the management of obesity and obesity-induced metabolic disorders, making it a prospective food supplement.

Potentiation of incretin hormones and modulation of metabolic enzymes as possible mechanisms behind the insulin sensitizing effects of cabbage-metformin treatment

In our study, we treated high fructose diet-induced insulin resistance in rats with any of metformin, cabbage (80%w/w) or combined metformin and cabbage (MetCabb), and observed the activities of glycolysis and gluconeogenesis regulatory enzymes, incretin hormones and other hormones affecting glucose homeostasis. Comparisons were made with normoglycemic noninsulin resistance rats (control) and insulin-resistant untreated rats (INres). Baseline analysis showing elevated fasting blood sugar (>250 mg/dl), insulin (>25 µIU/ml) and HOMA-IR (>10) satisfied the criteria for recruitment into the insulin-resistant groups. Treatment lasted for 12 weeks. HOMA-IR values significantly (P < 0.05) decreased from 24.7 to 5.5 and 10.6 respectively with MetCabb treatment. MetCabb normalized HOMA-IR values and mean β-cell responsiveness of the INres. Cabbage and metCabb normalized the leptin levels relative to control. The mean fasting blood sugar, insulin, and c-peptide levels with MetCabb treatment reverted to control levels. We found a strong positive linear correlation between the glucagon levels (r = 0.9145) and increasing HOMA-IR values while both incretin hormones; GLP-1 and GIP negatively regressed (r = -0.8084 and -0.8488). MetCab treatment produced comparable values of GLP-1 and GIP to the control. A strong positive correlation was found between the HOMA-IR values and the PEPCK (r = 0.9065), F-1,6-BPase (r = 0.7951), and G-6-Pase (r = 0.7893). The hexokinase (r = -0.807), PFK (r = -0.9151), and PK (r = -0.7448) levels regressed as HOMA-IR values increased. The glycolytic and gluconeogenic enzymes except PEPCK reverted to control levels with MetCabb treatment. Combination of metformin and cabbage was more effective than individual treatments.

Hydroxycinnamic acids and human health: recent advances

There is an urgent need to improve human diet globally. Compelling evidence gathered over the past several decades suggests that a suboptimal diet is associated with many chronic diseases and may be responsible for more deaths than any other risks worldwide. The main components in our diet that need higher intake are whole grains, fruit and vegetables, and nuts and seeds; all of these are important sources of dietary fiber and polyphenols. The health benefits of dietary fiber and polyphenols are also supported by several decades of valuable research. However, the conclusions drawn from interventional human trials are not straightforward and the action mechanisms in improving human health are not fully understood. Moreover, there is a great inter-individual variation caused by different individual capabilities of processing, absorbing and using these compounds effectively. Data on the bioavailability and bioefficacy of hydroxycinnamic acids (HCAs) are limited when compared to other classes of polyphenols (e.g. anthocyanins). This review aims to summarize the latest research advances related to HCA bioavailability and their biological effects revealed by epidemiological data, pre-clinical and clinical studies. Moreover, we aim to review the effects of HCAs on gut microbiota diversity and function and its respective influence on host health. © 2019 Society of Chemical Industry.

An overview of phytochemicals and potential health-promoting properties of black walnut

Black walnut contains a diverse mixture of bioactive compounds, including phenolics, phytosterols, unsaturated fatty acids, and tocopherols potentially important to human health.

Ferulic acid maintains the self-renewal capacity of embryo stem cells and adipose-derived mesenchymal stem cells in high fat diet-induced obese mice

Self-renewal is required for embryo stem cells (ESCs) and adipose-derived mesenchymal stem cells (ADMSCs). This study examined the ability of ferulic acid in mouse ESCs and ADMSCs, in a high fat diet-induced mouse model. Initially, five natural compounds of ferulic acid, xanthohumol, curcumin, ascorbic acid, and quercetin were screened in ESCs using an alkaline phosphate ⁺(AP⁺) assay, as a self-renewal biomarker. A ferulic acid treatment was the highest AP⁺ staining in hop-hit screening compounds. Also a ferulic acid increased Nanog mRNA levels in ESCs. The in vivo effects of ferulic acid were next examined in an obese mouse model. C57BL/6 J male mice were fed either a high fat diet (HFD) or control diet with ferulic acid (5 g/kg diet) for 8 weeks. Ferulic acid exhibited weight loss and improved glucose homeostasis, lipid profiling, and hepatic steatosis in a HFD-induced mouse model. Next, ADMSCs (Sca-1⁺CD45^-), a hallmark of fat stem cells, were then isolated and quantified from mouse abdominal adipose tissue. A HFD decreased the Sca-1⁺CD45^- cell population of ADMSCs, but HFD-induced obese mice given ferulic acid showed an increased the Sca-1⁺CD45^- cell population of ADMSCs. Moreover, ferulic acid enhanced NANOG mRNA levels in human ADMSCs and its related gene mRNA expression. Overall, this study suggests that ferulic acid preserves self-renewal in ESCs, and contributes to ADMSCs self-renewal and effective weight control in obesity.

The Effects and Mechanisms of Cyanidin-3-Glucoside and Its Phenolic Metabolites in Maintaining Intestinal Integrity

Cyanidin-3-glucoside (C3G) is a well-known natural anthocyanin and possesses antioxidant and anti-inflammatory properties. The catabolism of C3G in the gastrointestinal tract could produce bioactive phenolic metabolites, such as protocatechuic acid, phloroglucinaldehyde, vanillic acid, and ferulic acid, which enhance C3G bioavailability and contribute to both mucosal barrier and microbiota. To get an overview of the function and mechanisms of C3G and its phenolic metabolites, we review the accumulated data of the absorption and catabolism of C3G in the gastrointestine, and attempt to give crosstalk between the phenolic metabolites, gut microbiota, and mucosal innate immune signaling pathways.

Passion fruit peel intake decreases inflammatory response and reverts lipid peroxidation and adiposity in diet-induced obese rats

This study investigated Passiflora edulis peel flour (PEPF) intake and its effect against high-fat diet-induced obesity. PEPF is a source of fiber and phenolic compounds, which can decrease oxidative stress and inflammatory cytokines, both linked to chronic inflammatory response and fat deposition in obesity. Therefore, we hypothesized that PEPF intake could decrease inflammatory cytokines and oxidative stress observed in obesity, leading to decrease of fatness and chronic inflammatory response. The aims of the study were to evaluate the lipid peroxidation, the expression of antioxidants enzymes, and inflammatory parameters in obese rats. Male Sprague-Dawley rats were divided into 3 groups (n = 8 per group) according to the diets: control (based on AIN-93G), high-fat (HF, 35% fat w/w), and HF with PEPF (HFPF), and the experiment lasted for 10 weeks. PEPF showed high dietary fiber content and bioactive compounds, such as ferulic acid, and β-carotene. PEPF intake was effective in reducing body weight gain (13.31%) and total body fat (22.58%). The lipid peroxidation in the liver and adipose tissue decreased in the HFPF group compared to HF-fed animals, whereas hepatic glutathione peroxidase and glutathione reductase activity and their expressions in the liver were higher in HFPF than HF. In addition, the PEPF intake decreased inflammatory cytokines in serum. These results suggest that PEPF intake decreases oxidative stress, possibly by the increase of antioxidant enzymes expression. Furthermore, PEPF decreases inflammatory response and protects from adiposity. Then, PEPF could act as an adjuvant to control of early parameters in obesity dysfunction.

Fiber and phenolic compounds contribution to the hepatoprotective effects of mango diets in rats fed high cholesterol/sodium cholate

The present study evaluated the contribution of mango fiber (MF) and mango phenolic compounds (MP) to the hepatoprotective effect of freeze-dried mango pulp (FDM) cultivar (cv.) "Ataulfo" diets in high cholesterol/sodium cholate (HCC)-fed rats. Male Wistar rats were fed with a HCC diet for 12 weeks, either untreated, or supplemented with MF, MP, FDM, or a control diet (no HCC; n = 6/group). All mango treatments significantly decreased hepatic cholesterol deposition and altered its fatty acid profile, whereas MF and MP mitigated adipose tissue hypertrophy. MF caused a lower level of proinflammatory cytokines (IL-1α/β, IFN-γ, TNF-α) whereas FDM increased the anti-inflammatory ones (IL-4, 6, 10). Mango treatments increased catalase (CAT) activity and its mRNA expression; superoxide dismutase (SOD) activity was normalized by MF and FDM, but its activity was unrelated to its hepatic mRNA expression. Changes in CAT and SOD mRNA expression were unrelated to altered Nrf2 mRNA expression. Higher hepatic PPARα and LXRα mRNA levels were found in MP and MF. We concluded that MF and MP are highly bioactive, according to the documented hepatoprotection in HCC-fed rats; their mechanism of action appears to be related to modulating cholesterol and fatty acid metabolism as well as to stimulating the endogenous antioxidant system.

Ferulic acid ameliorates pentylenetetrazol-induced seizures by reducing neuron cell death

To investigate the neuroprotective effect of ferulic acid (FA) in a pentylenetetrazol (PTZ)-induced seizures model in rat, the motor response, spatial learning ability and memory capability of the rats were assessed. Both the antioxidation and anti-apoptosis pathways were also investigated. In this study, male Wistar rats were randomly divided into 3 groups (n = 12 in each group). For 28 days, the rats were administered saline alone (i.p. normal saline, NS group), PTZ (40 mg/kg, i.p., PTZ group) once daily to induce seizures, or FA (i.p. 60 mg/kg) 20 min before being given PTZ (40 mg/kg, i.p., FA + PTZ group) to assess the neuroprotective effect of FA. The motor response of the rats was analysed with the Racine scale. The spatial learning and memory capacity of the rats were assessed by the Morris water maze test. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured, and both in situ staining with the DNA-binding bisbenzimide Hoechst 33258 and TUNEL assays were used to assess apoptosis. Western blotting was used to further analyse the expression of Apaf-1, caspase-9, caspase-3, Bcl-2, Bid, Bax, cleaved caspase-3 and cytochrome c. The results showed that compared to the those of the PTZ group, FA pre-treatment significantly (p <  0.01) reduced the Racine scores starting at day 4, prolonged the latency of the onset of seizure at day 28, reduced the escape latency period starting at day 2, increased the frequency of crossing the platform location, increased the SOD activity, reduced the MDA content and apoptosis percentage, and upregulated the Bcl-2 levels whilst downregulating the Bax, cytochrome c, Apaf-1, caspase-9, caspase-3, cleaved caspase-3 and Bid expression levels. This study demonstrated that pre-treatment with FA exerts strong neuroprotective effects by reducing the motor response and by improving spatial learning ability and memory capacity. The neuroprotective effect may be a result of a reduction in neuron cell death that occurs via the antioxidative and anti-apoptotic pathways.

3-(4-Hydroxy-3-methoxyphenyl)propionic Acid Produced from 4-Hydroxy-3-methoxycinnamic Acid by Gut Microbiota Improves Host Metabolic Condition in Diet-Induced Obese Mice

4-Hydroxy-3-methoxycinnamic acid (HMCA), a hydroxycinnamic acid derivative, is abundant in fruits and vegetables, including oranges, carrots, rice bran, and coffee beans. Several beneficial effects of HMCA have been reported, including improvement of metabolic abnormalities in animal models and human studies. However, its mitigating effects on high-fat diet (HFD)-induced obesity, and the mechanism underlying these effects, remain to be elucidated. In this study, we demonstrated that dietary HMCA was efficacious against HFD-induced weight gain and hepatic steatosis, and that it improved insulin sensitivity. These metabolic benefits of HMCA were ascribable to 3-(4-hydroxy-3-methoxyphenyl)propionic acid (HMPA) produced by gut microbiota. Moreover, conversion of HMCA into HMPA was attributable to a wide variety of microbes belonging to the phylum Bacteroidetes. We further showed that HMPA modulated gut microbes associated with host metabolic homeostasis by increasing the abundance of organisms belonging to the phylum Bacteroidetes and reducing the abundance of the phylum Firmicutes. Collectively, these results suggest that HMPA derived from HMCA is metabolically beneficial, and regulates hepatic lipid metabolism, insulin sensitivity, and the gut microbial community. Our results provide insights for the development of functional foods and preventive medicines, based on the microbiota of the intestinal environment, for the prevention of metabolic disorders.

Effects of ripening on the in vitro antioxidant capacity and bioaccessibility of mango cv. 'Ataulfo' phenolics

Fruit ripening induces changes that strongly affect their matrices, and consequently, the bioaccessibility/bioavailability of its phenolic compounds. Flesh from 'slightly' (SR), 'moderately' (MR) and 'fully' (FR) ripe 'Ataulfo' mangoes were physicochemically characterized, and digested in vitro to evaluate how ripening impacts the bioaccessibility/bioavailability of its phenolic compounds. Ripening increased the flesh's pH and total soluble solids, while decreasing citric acid, malic acid and titratable acidity. MR and FR mango phenolics had higher bioaccessibility/bioavailability, which was related to a decreased starch and dietary fiber (soluble and insoluble) content. These results suggest that phenolics are strongly bound to the fruit's matrix of SR mango, but ripening liberates them as the major polysaccharides are hydrolyzed, thus breaking covalent bonds and disrupting carbohydrate-phenolic complexes. There was also a higher release percentage in the gastric digestion phase, as compared to the intestinal. Our data showed that the bioaccessibility/bioavailability of mango phenolics depends on fruit ripening and on digestion phase.

Pharmacokinetics, Bioavailability, and Tissue Distribution Study of Angoroside C and Its Metabolite Ferulic Acid in Rat Using UPLC-MS/MS

Angoroside C is a phenylpropanoid glycoside compound isolated from the dried root of Scrophularia ningpoensis Hemsl., which possesses the effects of preventing ventricular remodeling, reducing pulmonary oedema, and reducing blood pressure, as well as having the properties of anti-platelet aggregation, hepatoprotection and anti-nephritis, etc. However, few investigations have been conducted on the absorption, distribution, metabolism, and excretion (ADME) study of angoroside C. Thus, a fast ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method was established for the determination of angoroside C and its metabolite ferulic acid in rat plasma and tissue homogenate. The two analytes were extracted from the biosamples using a simple protein precipitation with acetonitrile. The developed method was validated and successfully applied to the pharmacokinetics, bioavailability and tissue distribution study after the intragastric administration of angoroside C (100 mg/kg) or the intravenous administration of angoroside C (5 mg/kg), respectively. The results showed that angoroside C can be absorbed extremely quickly (T_max = 15 min), can be eliminated very rapidly (t_1/2 = 1.26 h), and its oral bioavailability is only about 2.1%. Furthermore, angoroside C was extensively distributed in all main organs (liver, heart, spleen, lung, kidney, and brain), and the highest concentration was detected in the lung 15 min after oral administration. This paper also indicated that angoroside C could be converted to the active metabolite ferulic acid in vivo. The maximum concentrations of ferulic acid in the kidney occurred at 6 h after oral administration. In summary, this study explored some of the pharmacokinetic characteristics of angoroside C in vivo, and the data produced could provide a basis for the further investigation of angoroside C.

Curcumin as a functional food-derived factor: degradation products, metabolites, bioactivity, and future perspectives

Curcumin is a polyphenol found in turmeric (Curcuma longa), used as a spice, in food coloring, and as a traditional herbal medicine. It has been shown that curcumin has health benefits such as antioxidant, anti-inflammatory, and anticancer properties, improvement of brain function, and control of obesity and diabetes. However, native curcumin easily degrades and has low oral bioavailability, and a recent report has expressed doubt about curcumin's various effects. To overcome its low bioavailability, various curcumin formulations with enhanced bioavailability are currently being developed. This review discusses the chemistry, metabolism, and absorption of curcumin, to which various reported health benefits have been ascribed, as well as curcumin's degradation products and metabolites and their possible functions. Moreover, the research trend towards the obesity- and diabetes-preventing/suppressing aspects of curcumin and the latest case studies on highly water-dispersible and bioavailable curcumin formulations will be discussed. We summarize the challenges concerning research on curcumin's health benefits as follows: clarifying the relationship between curcumin's health benefits and the formation of curcumin-derived oxidation and degradation products and metabolites, determining whether curcumin itself or other components in turmeric are responsible for its effects, and conducting further human trials in which multiple research groups employ the same samples and conditions. High-bioavailability formulations would be useful in such future studies.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.