Phenolic acids alleviate high-fat and high-fructose diet-induced metabolic disorders in rats

Salvia deserti Decne., an endemic and rare subshrub from Arabian desert: antidiabetic and antihyperlipidemic effects of leaf hydroethanolic extracts

Introduction

Diabetes is a major health issue that has reached alarming levels worldwide. Although their effectiveness, the antidiabetic drugs have many side effects such as cardiovascular diseases, kidney failure, and hepatic complications. Many plant species of the genus Salvia L. such as "Arabian desert sage" (Salvia deserti) should began to be the focus of phytochemical and bioactivity studies.

Methods

The study aims to investigate, first-ever, the antidiabetic and antihyperlipidemic effects of the leaf hydroethanolic extract of S. deserti, an endemic and rare subshrub from Arabian desert. A single intraperitoneal injection of alloxan monohydrate (160 mg/kg) was used to induce type-2 diabetes. Development of diabetes was confirmed by measuring the blood glucose collected from the tail vein after 72 h of alloxan injection. Oral administration of hydroethanolic extracts of S. deserti at 200 and 400 mg/kg for 14 days were tested on the alloxan-induced diabetic mice and animals were divided into 6 groups of 6 mice each. The identity of phenolic compounds of the hydroethanolic extract of S. deserti was conducted through HPLC-Electrospray Ionization-Mass Spectrometry (LC-ESI-MS) analyses.

Results

Oral administration of hydroethanolic extract of S. deserti at 200 and 400 mg/kg for 14 days significantly decreased blood glucose and restored the hepatic and renal function by reducing the levels of ALT, AST, ALP, GGT, LDH, urea and creatinine. An improved lipid profile as revealed by the reduced levels of TC, TG and LDL coupled with increased level of HDL was also observed. Moreover, treatment with S. deserti hydroethanolic extract relieved oxidative stress (reduction of MDA and H2O2) and the activity of antioxidant enzymes SOD, CAT and GPx. The presence of several phenolic compounds (derivatives of ferulic, coumaric, and caffeic acids, among other derivatives) could at least in part explain the obtained data and empower the use of S. deserti as a source of bioactive ingredients with antioxidant, antidiabetic and antihyperlipidemic properties.

Discussion

Our research has unveiled S. deserti as a source of potential to effectively manage diabetes and its associated dyslipidemia by improving antioxidant status, recovery of the liver and kidney functions and presumably by increasing insulin secretion and sensitivity of peripheral tissues to insulin.

Ellagic acid alleviates high-fructose diet-induced non-alcoholic fatty liver disease by modulating liver metabolic profiles and gut microbiota

This study integrated analyses of gut microbiota and metabolomics to investigate the impact of ellagic acid (EA) on non-alcoholic fatty liver disease (NAFLD). Compared to the high-fructose diet (HFruD) group, the EA group exhibited reduced body weight and fat mass, alongside improvements in blood glucose and lipid metabolism. Liver metabolomics analysis revealed that EA increased the abundance of metabolites in pathways related to unsaturated fatty acids, amino acids and bile acids. Furthermore, EA induced alterations in the composition and structure of gut microbiota, notably decreasing bacterial genera enriched by HFruD while promoting beneficial bacteria such as Faecalibaculum. Correlation analysis demonstrated significant associations among NAFLD markers, gut microbiota and liver metabolites influenced by EA. This study provides new insights into the anti-NAFLD effects of EA, suggesting EA as a promising nutraceutical for improving NAFLD.

Research progress on the regulation of oxidative stress by phenolics: the role of gut microbiota and Nrf2 signaling pathway

In recent years, the increase in high-calorie diets and sedentary lifestyles has made obesity a global public health problem. An unbalanced diet promotes the production of proinflammatory cytokines and causes redox imbalance in the body. Phenolics have potent antioxidant activity and cytoprotective ability. They can scavenge free radicals and reactive oxygen species, and enhance the activity of antioxidant enzymes, thus combating the body's oxidative stress. They can also improve the body's inflammatory response, enhance the enzyme activity of lipid metabolism, and reduce the contents of cholesterol and triglyceride. Most phenolics are biotransformed and absorbed into the blood after the action by gut microbiota; these metabolites then undergo phase I and II metabolism and regulate oxidative stress by scavenging free radicals and increasing expression of antioxidant enzymes. Phenolics induce the expression of genes encoding antioxidant enzymes and phase II detoxification enzymes by stimulating Nrf2 to enter the nucleus and bind to the antioxidant response element after uncoupling from Keap1, thereby promoting the production of antioxidant enzymes and phase II detoxification enzymes. The absorption rate of phenolics in the small intestine is extremely low. Most phenolics reach the colon, where they interact with the microbiota and undergo a series of metabolism. Their metabolites will reach the liver via the portal vein and undergo conjugation reactions. Subsequently, the metabolites reach the whole body to exert biological activity by traveling with the systemic circulation. Phenolics can promote the growth of probiotics, reduce the ratio of Firmicutes/Bacteroidetes (F/B), and improve intestinal microecological imbalance. This paper reviews the nutritional value, bioactivity, and antioxidant mechanism of phenolics in the body, aiming to provide a scientific basis for the development and utilization of natural antioxidants and provide a reference for elucidating the mechanism of action of phenolics for regulating oxidative stress in the body. © 2023 Society of Chemical Industry.

Ameliorative Effects of Anthocyanin Metabolites on Western Diet-Induced NAFLD by Modulating Co-Occurrence Networks of Gut Microbiome

Anthocyanins (Acn) have been reported to have preventive effects on Western diet (WD)-induced non-alcoholic fatty liver disease (NAFLD). However, the amount of Acn that reached the bloodstream were less than 1%, suggesting that anthocyanin metabolites (Acn-M) in the gut may contribute to their in vivo effects. This study is focused on a gut microbiota investigation to elucidate the effect of two major Acn-M, protocatechuic acid (PC) and phloroglucinol carboxaldehyde (PG), on NAFLD prevention. C57BL/6N male mice were divided into five groups and fed with a normal diet (ND), WD, WD + 0.5% PC, WD + 0.5% PG and WD + a mixture of 0.25% PC + 0.25% PG (CG) for 12 weeks. The results revealed that WD-fed mice showed a significant increase in final body weight, epididymis fat weight, liver weight and fat accumulation rate, serum total cholesterol, alanine aminotransferase, monocyte chemoattractant protein 1, and 2-thiobarbituric acid reactive substances. At the same time, these indices were significantly decreased by Acn-M in the order of PG, CG > PC. In particular, PG significantly decreased serum glucose and insulin resistance. Gut microbiome analysis revealed that PG significantly increased the relative abundance of Parabacteroides, Prevotella, Prevotella/Bacteroides ratio, and upregulated glucose degradation pathway. Interestingly, the co-occurrence networks of Lachnospiraceae and Desulfovibrionaceae in the PC and PG groups were similar to the ND group and different to WD group. These data suggest that PC and PG were able to recover the gut microbiome networks and functions from dysbiosis caused by WD. Therefore, PG might act as a master metabolite for anthocyanins and prevent WD-induced NAFLD and gut dysbiosis.

Uncovering the effect of Moringa oleifera Lam. leaf addition to Fuzhuan Brick Tea on sensory properties, volatile profiles and anti-obesity activity

As a nutritious plant with valuable potential, the Moringa oleifera Lam. leaf addition to Fuzhuan Brick Tea (FBT) for co-fermentation is an industrial innovation and a new route to make full use of Moringa oleifera Lam. leaves. However, the sensory properties, volatile profiles and anti-obesity activity of Fuzhuan Brick (Moringa oleifera Lam.) tea (MFBT) are still unknown. The results demonstrated that MFBT has richer and more complex smell and taste, better color and higher overall acceptance scores. In total, 57 volatile flavor compounds, consisting of 3 acids, 16 hydrocarbons, 5 esters, 8 ketones, 13 aldehydes, 6 alcohols and others, were identified using HS-SPME-GC-MS. The characteristic odor components in MFBT were 3-buten-2-one, 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)- and 1-cyclohexene-1-carboxaldehyde, 2,6,6-trimethyl-, which gave it a floral, woody, sweet, herbal and fruity aroma. 2-Octenal, (E) contributed significantly to the aroma of FBT, which could impart fresh, fatty and green aromas. In addition, MFBT could better regulate lipid accumulation, glucose tolerance, insulin tolerance and inflammation response more effectively than FBT. The mechanism is that MFBT could better regulate the dysbiosis of gut microbiota induced by HFFD, mainly increasing the abundance of beneficial bacteria such as SCFA-producing bacteria (Bacteroidetes, Lactobacillaceae, Bacteroidales_S24-7_group and Clostridiaceae_1) and decreasing the abundance of harmful bacteria such as pro-inflammatory/obesity and metabolic syndrome-related bacteria (Proteobacteria, Deferribacteres, Desulfovibrio, Catenibacterium and Helicobacter), which in turn increased feces short-chain fatty acids and lowered circulating lipopolysaccharides. These results suggested that co-fermentation with Moringa oleifera Lam. leaf could significantly improve the quality and enhance the anti-obesity effect of FBT.

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.

Recent Studies on Protective Effects of Walnuts against Neuroinflammation

Neuroinflammation plays a significant role in the aging process and the pathophysiology of neurodegenerative diseases, such as Alzheimer’s disease. Accordingly, possible therapeutic strategies aimed at anti-inflammatory effects may be beneficial to brain health. Walnut kernels contain large quantities of unsaturated fatty acids, peptides, and phenolic compounds that have anti-inflammatory effects. The long-term intake of walnuts has been found to improve cognitive function and memory in rats and humans. However, the modulatory effect of walnuts on neuroinflammation has received much less attention. This review focuses on the potential influence and main regulating mechanisms of walnuts and their active ingredients on neuroinflammation, including the regulation of microglia activation induced by amyloid β or lipopolysaccharides, inhibition of peripheral inflammation mediated by macrophages, reduction in oxidative stress by decreasing free radical levels and boosting antioxidant defenses, and control of gut microbes to maintain homeostasis. However, the majority of evidence of the beneficial effects of walnuts or their components on neuroinflammation and neurodegeneration comes from experimental work, whereas evidence from clinical studies on the beneficial effects is scarcer and less conclusive. This review aims to provide new insights into the neuroinflammation-regulating mechanisms and natural active ingredients of walnuts and the development of walnut-based functional foods for the alleviation of neurodegenerative diseases.

Dietary Ferulic Acid Ameliorates Metabolism Syndrome-Associated Hyperuricemia in Rats via Regulating Uric Acid Synthesis, Glycolipid Metabolism, and Hepatic Injury

Ferulic acid is a well-known phenolic acid compound and possesses multiple health-promoting and pharmacological effects. Metabolic syndrome (MetS) and hyperuricemia (HUA) have become health problems worldwide and are closely connected. The aim of this study was to explore the influence of ferulic acid on MetS-related HUA and its underlying mechanisms. Rats were administered high-fructose and high-fat diet (HFFD) with or without ferulic acid (0.05 and 0.1%) for 20 weeks. Intake of HFFD resulted in obesity, hyperglycemia, insulin resistance, and dyslipidemia, which were alleviated by ferulic acid consumption. Treatment of rats with ferulic acid diminished the levels of lipids and inflammatory cytokines and enhanced the activities of antioxidant enzymes in the liver caused by HFFD. Additionally, administration of ferulic acid blocked a HFFD-induced elevation in activities and mRNA expression of enzymes involving in uric acid (UA) synthesis. Molecular docking analysis denoted that ferulic acid bound to the active center of these enzymes, indicative of the potential interaction with each other. These two aspects might partially be responsible for the decrement in serum UA content after ferulic acid ingestion. In conclusion, ferulic acid supplementation ameliorated lipid and glucose metabolic abnormalities, hepatic damage, and UA formation in MetS rats. There was a dose correlation between lipid deposition and UA synthesis-related indicators. These findings implied that ferulic acid could be applied as a promising dietary remedy for the management of MetS-associated HUA.

High cholesterol diet promotes dysfunction of arginase and cholinergic enzymatic system in rats: ameliorative role of caffeic and chlorogenic acids

BACKGROUND

Dietary phenolic compounds intake have been reported to have an inverse relationship to the prevalence of hypercholesterolemia. The objective of this study is to determine the effect of caffeic acid (CFA) and chlorogenic acid (CGA) on rats fed with high cholesterol diet (HCD).

METHODS

Experimental animals were fed with high cholesterol diet (HCD) for a period of 21 days while simvastatin (0.2 mg/kg BWT), CFA and CGA (10 and 15 mg/kg BWT) were administered daily.

RESULTS

Activity of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and arginase were significantly (P<0.05) higher in the rats fed with HCD alone. Also, level of malondiadehyde equivalent compounds (MDA) was significantly (P<0.05) elevated in hypercholesterolemic rats. Nevertheless, treatment with simvastatin, CFA and CGA normalized altered AChE, BChE and arginase activities as well as improved antioxidant status in hypercholesterolemic rats.

CONCLUSION

CFA and CGA could offer protective role in hypercholeseterolemic rats via their antioxidant potentials as well as restoring altered activity of acetylcholinesterase, butrylcholinesterase and arginase. Based on our findings chlorogenic acid exhibits better attribute.

Red raspberry extract (Rubus idaeus L shrub) intake ameliorates hyperlipidemia in HFD-induced mice through PPAR signaling pathway

Effects of red raspberry extract (RRE) intake on hyperlipidemia mice induced by high-fat diet (HFD) were investigated in this study. After intragastric gavage of RRE for 8 weeks, the body weight and the adipose tissue mass of mice in RRE administration groups significantly (p < 0.05) decreased compared to the group without RRE treatment. RRE treatment significantly (p < 0.05) lowered triglyceride and total cholesterol levels of hyperlipidemia mice. Pparα, Hmgcr, Ldlr, Cyp7a1, Acsl3, Pnpla2 and Pin4 were confirmed as the regulatory genes by transcriptome analysis and qRCR validation. According to KEGG pathway analysis, target genes such as Cyp7a1 and Pin4 were further regulated by the activation of PPARα resulting from RRE supplementation. Meanwhile, liver cholesterol synthesis and conversion were inhibited by the expressions of Hmgcr and Cyp7a1 genes regulated by RRE intake, and Ldlr gene was down-regulated to limit the transport of cholesterol. In addition, RRE treatment could accelerate the conversion from triglyceride to fatty acid. To conclusion, RRE intake would be a protection against diet-induced hypertriglyceridemia.

Cardio-protective and antioxidant properties of caffeic acid and chlorogenic acid: Mechanistic role of angiotensin converting enzyme, cholinesterase and arginase activities in cyclosporine induced hypertensive rats

Caffeic acid (CAA) and chlorogenic acid (CHA) are important members of hydroxycinnamic acid with natural antioxidant and cardio-protective properties. The present study aimed to determine the effect of CAA and CHA on systolic blood pressure, heart rates (HR) as well as on the activity of the angiotensin-1-converting enzyme (ACE), acetylcholinesterase (AChE), butrylcholinesterase (BChE) and arginase in cyclosporine-induced hypertensive rats. Experimental rats were distributed into 7 groups (n = 6): normotensive control rats; hypertensive rats (induced rats) as well as hypertensive- treated groups with captopril (10 mg/kg/day), CAA (10 and 15 mg/kg/day) and CHA (10 and 15 mg/kg/day), respectively. The experiment lasted for 7 days and the systolic blood pressure (SBP) and heart rates were recorded using tail-cuff method. Oral administration of captopril, caffeic acid and chlorogenic acid normalized hypertensive effect caused by cyclosporine administration. CAA and CHA significantly (P < 0.05) reduced SBP and HR, activity of ACE, AChE, BChE and arginase in the treated hypertensive rats compared with cyclosporine induced-hypertensive rats. Likewise, CAA and CHA improved nitric oxide (NO) bioavailability, increased catalase activity and reduced glutathione content while malondialdehyde (MDA) level was reduced compared with cyclosporine hypertensive rats. Findings from this study shows that CAA and CHA exhibited blood pressure lowering properties and reduced activities of key enzymes linked to the pathogenesis of hypertension in cyclosporine-induced rats. These might be some of the possible mechanisms of action by which their cardio-protective properties are exhibited.