Rosmarinic acid administration attenuates diabetes-induced vascular dysfunction of the rat aorta

Network pharmacology, molecular docking, and in vitro experimental verification of the mechanism of Guanxining in treating diabetic atherosclerosis

ETHNOPHARMACOLOGICAL RELEVANCE

Guanxinning(GXN) tablet is a patented traditional Chinese medicine widely used to prevent and treat cardiovascular diseases. However, its potential mechanism and target in anti-diabetic atherosclerosis have not been clarified.

AIM

The aim of this study was to investigate the underlying targets and mechanisms of action GXN in the treatment of diabetic atherosclerosis, employing a combination of network pharmacology, molecular docking, and in vitro experimental verification.

METHODS

We predicted the core components and targets of GXN in the treatment of diabetic atherosclerosis through various databases, and made analysis and molecular docking. In vitro, we induced injury in human umbilical vein endothelial cells using glucose/palmitate and observed the effects of GXN on cellular damage high-glucose and high-fat conditions, subsequently elucidating its molecular mechanisms.

RESULTS

A total of 14 active components and 157 targets of GXN were identified. Using the PPI network, we selected 9 core active components and 20 targets of GXN. GO functional analysis revealed that these targets were primarily associated with apoptosis signaling pathways in response to endoplasmic reticulum stress and reactive oxygen species responses. Molecular docking confirmed the strong binding affinities of the primary active components of GXN with ERN1, MAPK1 and BECN1. In vitro experiments demonstrated the ability of GXN to restore endothelial cell activity, enhance cell migration and inhibit sICAM secretion, and upregulate the expression of endoplasmic reticulum stress-related proteins (IRE1, XBP1) and autophagy-related proteins (Beclin1, LC3A, and LC3B), while simultaneously inhibiting endothelial cell apoptosis under high-glucose and high-fat conditions.

CONCLUSIONS

Our findings suggest that GXN can potentially safeguard endothelial cells from the adverse effects of high-glucose and high-fat by modulating the interactions between endoplasmic reticulum stress and autophagy. Therefore, GXN is a promising candidate for the prevention and treatment of diabetic atherosclerosis.

Targeting the JAK2/STAT3 signaling pathway with natural plants and phytochemical ingredients: A novel therapeutic method for combatting cardiovascular diseases

The aim of this article is to introduce the roles and mechanisms of the JAK2/STAT3 pathway in various cardiovascular diseases, such as myocardial fibrosis, cardiac hypertrophy, atherosclerosis, myocardial infarction, and myocardial ischemiareperfusion. In addition, the effects of phytochemical ingredients and different natural plants, mainly traditional Chinese medicines, on the regulation of different cardiovascular diseases via the JAK2/STAT3 pathway are discussed. Surprisingly, the JAK2 pathway has dual roles in different cardiovascular diseases. Future research should focus on the dual regulatory effects of different phytochemical ingredients and natural plants on JAK2 to pave the way for their use in clinical trials.

Rosmarinic Acid Activates the Nrf2/ARE Signaling Pathway via the miR-25-3p/SIRT6 Axis to Inhibit Vascular Remodeling

The vital pathological processes in intimal hyperplasia include aberrant vascular smooth muscle cells (VSMCs) proliferation, migration, and phenotypic switching. Rosmarinic acid (RA) is a natural phenolic acid compound. Nevertheless, the underlying mechanism of RA in neointimal hyperplasia is still unclear. Our analysis illustrated that miR-25-3p mimics significantly enhanced PDGF-BB-mediated VSMCs proliferation, migration, and phenotypic switching while RA partially weakened the effect of miR-25-3p. Mechanistically, we found that miR-25-3p directly targets sirtuin (SIRT6). The suppressive effect of the miR-25-3p inhibitor on PDGF-BB-induced VSMCs proliferation, migration, and phenotypic switch was partially eliminated by SIRT6 knockdown. The suppression of the PDGF-BB-stimulated Nrf2/ARE signaling pathway that was activated by the miR-25-3p inhibitor was exacerbated by the SIRT6 knockdown. In in vivo experiments, RA reduced the degree of intimal hyperplasia while miR-25-3p agomir partially reversed the suppressive effect of RA in vascular remodeling. Our results indicate that RA activates the Nrf2/ARE signaling pathway via the miR-25-3p/SIRT6 axis to inhibit vascular remodeling.

Potential of rosmarinic acid from Orthosiphon aristatus extract for inflammatory induced diseases and its mechanisms of action

Orthosiphon aristatus has been traditionally used as a medicinal herb for various illnesses in Southeast Asia and Europe. The most dominant bioactive compound of the herb is rosmarinic acid (RosA) which has been demonstrated for its remarkable anti-inflammatory properties. This review describes the recent progress of studies on multi-target molecular pathways of RosA in relation to targeted inflammatory-associated diseases. An inclusive literature search was conducted using electronic databases such as Google Scholar, Scopus, Springer Link, PubMed, Medline, Wiley and Science Direct for studies reporting on the anti-inflammatory actions of RosA from 2008 until 2023. The keywords of the search were RosA and anti-inflammatory in relation to hepatoprotective, chondroprotective, cardioprotective, neuroprotective and toxicity. Only publications that are written in English are included in this review. The inhibition and deactivation of pro-inflammatory biomolecules by RosA were explained based on the initial inflammation stimuli and their location in the body. The activation of Nrf2/HO-1 expression to inhibit NF-κB pathway is the key mechanism for hepatoprotection. Besides NF-κB inhibition, RosA activates PPARγ to alleviate ischemia/reperfusion (I/R)-induced myocardial injury for cardioprotection. The regulation of MAPK and T-cell activation is important for chondroprotection, whereas the anti-oxidant property of RosA is the main contributor of neuroprotection. Even though less studies on the anti-inflammation of RosA extracts from O. aristatus, but the effective pharmacological properties of RosA has promoted it as a natural potent lead for further investigation.

Adding SGLT2 Cotransporter Inhibitor to PPARγ Activator Does Not Provide an Additive Effect in the Management of Diabetes-Induced Vascular Dysfunction

INTRODUCTION

Endothelial dysfunction (ED) plays a key role in the pathogenesis of diabetic vascular complications. In monotherapy, dapagliflozin (Dapa) as well as pioglitazone (Pio) prevent the progression of target organ damage in both type 1 (T1DM) and type 2 diabetes. We investigated whether the simultaneous PPAR-γ activation and SGLT2 cotransporter inhibition significantly alleviate ED-related pathological processes and thus normalize vascular response in experimental T1DM.

METHODS

Experimental diabetes was induced by streptozotocin (STZ; 55 mg/kg, i.p.) in Wistar rats. Dapa (10 mg/kg), Pio (12 mg/kg), or their combination were administrated to the STZ rats orally. Six weeks after STZ administration, the aorta was excised for functional studies and real-time qPCR analysis.

RESULTS

In the aorta of diabetic rats, impaired endothelium-dependent and independent relaxation were accompanied by the imbalance between vasoactive factors (eNos, Et1) and overexpression of inflammation (Tnfα, Il1b, Il6, Icam, Vcam) and oxidative stress (Cybb) markers. Pio monotherapy normalized response to vasoactive substances and restored balance between Et1-eNos expression, while Dapa treatment was ineffective. Nevertheless, Dapa and Pio monotherapy significantly reverted inflammation and oxidative stress markers to normal values. The combination treatment exhibited an additive effect in modulating Il6 expression, reaching the effect of Pio monotherapy in other measured parameters.

CONCLUSION

Particularly, Pio exerts a vasoprotective character when used in monotherapy. When combined with Dapa, it does not exhibit an expected additive effect within modulating vasoreactivity or oxidative stress, though having a significant influence on IL6 downregulation.

Comprehensive Insights into Biological Roles of Rosmarinic Acid: Implications in Diabetes, Cancer and Neurodegenerative Diseases

Phytochemicals are abundantly occurring natural compounds extracted from plant sources. Rosmarinic acid (RA) is an abundant phytochemical of Lamiaceae species with various therapeutic implications for human health. In recent years, natural compounds have gained significant attention as adjuvant and complementary therapies to existing medications for various diseases. RA has gained popularity due to its anti-inflammatory and antioxidant properties and its roles in various life-threatening conditions, such as cancer, neurodegeneration, diabetes, etc. The present review aims to offer a comprehensive insight into the multifaceted therapeutic properties of RA, including its potential as an anticancer agent, neuroprotective effects, and antidiabetic potential. Based on the available evidences, RA could be considered a potential dietary component for treating various diseases, including cancer, diabetes and neurodegenerative disorders.

Sensitive Detection of Rosmarinic Acid Using Peptide-Modified Graphene Oxide Screen-Printed Carbon Electrode

Peptides have been used as components in biological analysis and fabrication of novel sensors due to several reasons, including well-known synthesis protocols, diverse structures, and acting as highly selective substrates for enzymes. Bio-conjugation strategies can provide a simple and efficient way to convert peptide-analyte interaction information into a measurable signal, which can be further used for the manufacture of new peptide-based biosensors. This paper describes the sensitive properties of a peptide-modified graphene oxide screen-printed carbon electrode for accurate and sensitive detection of a natural polyphenol antioxidant compound, namely rosmarinic acid. Glutaraldehyde was chosen as the cross-linking agent because it is able to bind nonspecifically to the peptide. We demonstrated that the strong interaction between the immobilized peptide on the surface of the sensor and rosmarinic acid favors the addition of rosmarinic acid on the surface of the electrode, leading to an efficient preconcentration that determines a high sensitivity of the sensor for the detection of rosmarinic acid. The experimental conditions were optimized using different pH values and different amounts of peptide to modify the sensor surface, so that its analytical performances were optimal for rosmarinic acid detection. By using cyclic voltammetry (CV) as a detection method, a very low detection limit (0.0966 μM) and a vast linearity domain, ranging from 0.1 µM to 3.20 µM, were obtained. The novelty of this work is the development of a novel peptide-based sensor with improved performance characteristics for the quantification of rosmarinic acid in cosmetic products of complex composition. The FTIR method was used to validate the voltammetric method results.

Rosmarinic acid downregulates the oxLDL‑induced interaction between monocytes and endothelial cells, in addition to monocyte diapedesis, under high glucose conditions

Endothelial dysfunction during diabetes has been previously reported to be at least in part attributed to increased oxidized low‑density lipoprotein (oxLDL) levels mediated by high glucose (HG) levels. Endothelial inflammation increases the adhesiveness of monocytes to the endothelium in addition to increasing vascular permeability, promoting diabetic atherogenesis. In a previous study, it was reported that oxLDL treatment induced nucleotide‑binding domain and leucine‑rich repeat containing family, pyrin domain‑containing 3 inflammasome activation in endothelial cells (ECs) under HG conditions, in a manner that could be effectively reversed by rosmarinic acid. However, it remains unclear whether oxLDL‑mediated inflammasome activation can regulate the interaction between monocytes and ECs. The effects of oxLDL‑mediated inflammasome activation on endothelial permeability under HG conditions, in addition to the effects of rosmarinic acid on these oxLDL‑mediated processes, also remain poorly understood. Therefore, the present study aimed to elucidate the mechanisms involved in oxLDL‑induced endothelial permeability and monocyte diapedesis under HG conditions, in addition to the potential effects of rosmarinic acid. ECs were treated with oxLDL under HG conditions in the presence or absence of ROS scavengers mitoTEMPO and NAC, p38 inhibitor SB203580, FOXO1 inhibitor AS1842856 or transfected with the TXNIP siRNA, before protein expression levels of intercellular adhesion molecule 1 (ICAM‑1), vascular cell adhesion molecule‑1 (VCAM‑1), phosphorylated vascular endothelial‑cadherin (VE‑cadhedrin), VE‑cadherin and zonula occludens‑1 (ZO‑1) were measured by western blotting. In addition, adhesion assay and Transwell assays were performed. oxLDL was found to significantly increase the expression of ICAM‑1 and VCAM‑1 in ECs under HG conditions whilst also enhancing the adhesion of monocytes to ECs. This was found to be dependent on the reactive oxygen species (ROS)/p38 MAPK/forkhead box O1 (FOXO1)/thioredoxin interacting protein (TXNIP) signaling pathway. In addition, oxLDL‑stimulated ECs under HG conditions exhibited increased phosphorylated VE‑cadherin protein levels and decreased ZO‑1 protein expression levels compared with those in untreated ECs, suggesting increased endothelial permeability. Furthermore, monocyte transmigration through the endothelial monolayer was significantly increased by oxLDL treatment under HG conditions. These oxLDL‑mediated effects under HG conditions were also demonstrated to be dependent on this ROS/p38 MAPK/FOXO1/TXNIP signaling pathway. Subsequently, rosmarinic acid treatment significantly reversed oxLDL‑induced overexpression of adhesion molecules and monocyte‑EC adhesion, oxLDL‑induced endothelial junction hyperpermeability and monocyte transmigration through the endothelial monolayer under HG conditions, in a dose‑dependent manner. These results suggest that rosmarinic acid can exert a protective effect against oxLDL‑mediated endothelial dysfunction under HG conditions by reducing the interaction between monocytes and ECs in addition to preventing monocyte diapedesis.

Biomedical features and therapeutic potential of rosmarinic acid

For decades, the use of secondary metabolites of various herbs has been an attractive strategy in combating human diseases. Rosmarinic acid (RA) is a bioactive phenolic compound commonly found in plants of Lamiaceae and Boraginaceae families. RA is biosynthesized using amino acids tyrosine and phenylalanine via enzyme-catalyzed reactions. However, the chemical synthesis of RA involves an esterification reaction between caffeic acid and 3,4-dihydroxy phenyl lactic acid contributing two phenolic rings to the structure of RA. Several studies have ascertained multiple therapeutic benefits of RA in various diseases, including cancer, diabetes, inflammatory disorders, neurodegenerative disorders, and liver diseases. Many previous scientific papers indicate that RA can be used as an anti-plasmodic, anti-viral and anti-bacterial drug. In addition, due to its high anti-oxidant capacity, this natural polyphenol has recently gained attention for its possible application as a nutraceutical compound in the food industry. Here we provide state-of-the-art, flexible therapeutic potential and biomedical features of RA, its implications and multiple uses. Along with various valuable applications in safeguarding human health, this review further summarizes the therapeutic advantages of RA in various human diseases, including cancer, diabetes, neurodegenerative diseases. Furthermore, the challenges associated with the clinical applicability of RA have also been discussed.

Rosmarinic acid alleviates diabetic osteoporosis by suppressing the activation of NLRP3 inflammasome in rats

BACKGROUND

Diabetic osteoporosis is a common metabolic bone disorder characterized by bone loss in diabetic patients, which causes an enormous social burden due to the unsatisfactory outcome of current therapeutic strategy.

METHODS

Based on the importance of inflammasome activation in diabetic osteoporosis, we evaluated the protective effect of an antioxidant, rosmarinic acid (RA) in diabetic osteoporosis. Bone marrow-derived monocytes isolated from rats were treated with receptor activator of nuclear factor kappa-Β ligand (RANKL) and macrophage colony stimulating factor to differentiate into mature osteoclasts (OCs). Next OCs were stimulated with RA under high glucose condition to evaluate bone resorption. Next, streptozotocin (STZ)-injected rats were orally treated with 50 mg kg-1 RA to analyze its effect on diabetic osteoporosis.

RESULTS

RA inhibited high glucose-stimulated inflammation and inflammasome activation in OCs. Bone resorption was also reduced after RA treatment as shown by the resorption pits assay. Moreover, RA significantly reduced bone resorption, alleviated bone weight loss and increased bone mineral density by inhibiting the activation of NACHT-LRR-PYD domains-containing protein 3 (NLRP3) inflammasome in STZ-induced diabetic rats, leading to the improvement of diabetic osteoporosis.

CONCLUSION

RA effectively ameliorates diabetic osteoporosis in STZ-induced rats by inhibiting the activation of NLRP3 inflammasome in OCs, which suggests that RA might serve as a potential candidate drug for treating diabetic osteoporosis.

Potential Anti-Inflammatory Effect of Rosmarinus officinalis in Preclinical In Vivo Models of Inflammation

This systematic review aimed to evaluate the potential anti-inflammatory effect of Rosmarinus officinalis in preclinical in vivo models of inflammation. A search was conducted in the databases PubMed, Scopus, and Web of Science, with related keywords. The inclusion criteria were inflammation, plant, and studies on rats or mice; while, the exclusion criteria were reviews, studies with in vitro models, and associated plants. The predominant animal models were paw edema, acute liver injury, and asthma. Rosemary was more commonly used in its entirety than in compounds, and the prevalent methods of extraction were maceration and hydrodistillation. The most common routes of administration reported were gavage, intraperitoneal, and oral, on a route-dependent dosage. Treatment took place daily, or was single-dose, on average for 21 days, and it more often started before the induction. The most evaluated biomarkers were tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10, myeloperoxidase (MPO), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), malondialdehyde (MDA), and superoxide dismutase (SOD). The best results emerged at a dose of 60 mg/kg, via IP of carnosic acid, a dose of 400 mg/kg via gavage of Rosmarinus officinalis, and a dose of 10 mg/kg via IP of rosmarinic acid. Rosmarinus officinalis L. showed anti-inflammatory activity before and after induction of treatments.

A Systematic Review of Orthosiphon stamineus Benth. in the Treatment of Diabetes and Its Complications

(1) Background: Orthosiphon stamineus Benth. is a traditional medicine used in the treatment of diabetes and chronic renal failure in southern China, Malaysia, and Thailand. Diabetes is a chronic metabolic disease and the number of diabetic patients in the world is increasing. This review aimed to systematically review the effects of O. stamineus in the treatment of diabetes and its complications and the pharmacodynamic material basis. (2) Methods: This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the databases ScienceDirect, PubMed, and Web of Science. (3) Results: Thirty-one articles related to O. stamineus and diabetes were included. The mechanisms of O. stamineus in the treatment of diabetes and its complications mainly included inhibiting α-amylase and α-glucosidase activities, antioxidant and anti-inflammatory activities, regulating lipid metabolism, promoting insulin secretion, ameliorating insulin resistance, increasing glucose uptake, promoting glycolysis, inhibiting gluconeogenesis, promoting glucagon-likepeptide-1 (GLP-1) secretion and antiglycation activity. Phenolic acids, flavonoids and triterpenoids might be the main components for hypoglycemia effects in O. stamineus. (4) Conclusion: O. stamineus could be an antidiabetic agent to treat diabetes and its complications. However, it needs further study on a pharmacodynamic substance basis and the mechanisms of effective constituents.

Antidepressant-like effect of rosmarinic acid during LPS-induced neuroinflammatory model: The potential role of cannabinoid receptors/PPAR-γ signaling pathway

Rosmarinic acid (RA), an ester of caffeic acid and 3, 4-dihydroxyphenyllactic acid, has anti-inflammatory and neuroprotective activities. Herein, this study investigated in silico the drug-likeness and the potential molecular targets to RA. Moreover, it tested the antidepressant-like potential of RA in the lipopolysaccharide (LPS)-induced depression model. RA (MW = 360.31 g/mol) meets the criteria of both Lipinski's rule of five and the Ghose filter. It also attends to relevant pharmacokinetic parameters. Target prediction analysis identified RA's potential targets and biological activities, including the peroxisome proliferator-activated receptor (PPAR) and the cannabinoid receptors CB1 and CB2 . In vivo, RA's acute, repetitive, and therapeutic administration showed antidepressant-like effect since it significantly reduced the immobility time in the tail suspension test and increased grooming time in the splash test. Further, the pretreatment with antagonists of CB1 , CB2 , and PPAR-γ receptors significantly blocked the antidepressant-like effect of RA. Altogether, our findings suggest that cannabinoid receptors/PPAR-γ signaling pathways are involved with the antidepressant-like effect of RA. Moreover, this molecule meets important physicochemical and pharmacokinetic parameters that favor its bioavailability. RA constitutes a promising, innovative, and safe molecule for the pharmacotherapy of major depressive disorder.

Rosmarinic Acid Increases Macrophage Cholesterol Efflux through Regulation of ABCA1 and ABCG1 in Different Mechanisms

Lipid dysregulation in diabetes mellitus escalates endothelial dysfunction, the initial event in the development and progression of diabetic atherosclerosis. In addition, lipid-laden macrophage accumulation in the arterial wall plays a significant role in the pathology of diabetes-associated atherosclerosis. Therefore, inhibition of endothelial dysfunction and enhancement of macrophage cholesterol efflux is the important antiatherogenic mechanism. Rosmarinic acid (RA) possesses beneficial properties, including its anti-inflammatory, antioxidant, antidiabetic and cardioprotective effects. We previously reported that RA effectively inhibits diabetic endothelial dysfunction by inhibiting inflammasome activation in endothelial cells. However, its effect on cholesterol efflux remains unknown. Therefore, in this study, we aimed to assess the effect of RA on cholesterol efflux and its underlying mechanisms in macrophages. RA effectively reduced oxLDL-induced cholesterol contents under high glucose (HG) conditions in macrophages. RA enhanced ATP-binding cassette transporter A1 (ABCA1) and G1 (ABCG1) expression, promoting macrophage cholesterol efflux. Mechanistically, RA differentially regulated ABCA1 expression through JAK2/STAT3, JNK and PKC-p38 and ABCG1 expression through JAK2/STAT3, JNK and PKC-ERK1/2/p38 in macrophages. Moreover, RA primarily stabilized ABCA1 rather than ABCG1 protein levels by impairing protein degradation. These findings suggest RA as a candidate therapeutic to prevent atherosclerotic cardiovascular disease complications related to diabetes by regulating cholesterol efflux in macrophages.

Rosmarinic acid inhibits oxLDL-induced inflammasome activation under high-glucose conditions through downregulating the p38-FOXO1-TXNIP pathway

Elevated glucose levels in diabetes mellitus is associated with increased oxidized low density lipoprotein (oxLDL). High glucose (HG) and oxLDL are key inducers of oxidative stress and inflammatory processes responsible for diabetic vascular disorders. Rosmarinic acid is a polyphenol with antioxidant, anti-inflammatory and insulin-sensitizing effects. However, whether rosmarinic acid protects against diabetic atherosclerosis remains unknown. In this study, we aimed to investigate the protective effect of rosmarinic acid against diabetic atherosclerosis and the related signaling pathway. oxLDL-mediated oxidative stress upregulated thioredoxin-interacting protein (TXNIP) and subsequently induced binding of TXNIP to NLRP3 to mediate NLRP3 inflammasome assembly and activation under HG conditions in ECs. Reactive oxygen species (ROS) scavengers, p38 and FOXO1 inhibitors and TXNIP siRNA inhibited TXNIP protein upregulation and NLRP3 inflammasome assembly and activation. Rosmarinic acid abrogated TXNIP protein upregulation and the interaction between TXNIP and NLRP3 to attenuate NLRP3 inflammasome assembly and activation and eventually IL-1β secretion in ECs through downregulating ROS production, p38 phosphorylation and FOXO1 protein induction in ECs. These findings show that rosmarinic acid inhibits endothelial dysfunction which is shown in diabetic atherosclerosis through downregulating the p38-FOXO1-TXNIP pathway and inhibiting inflammasome activation.

Impact of improving eating habits and rosmarinic acid supplementation on rat vascular and neuronal system in the metabolic syndrome model

Decreasing high fat and high carbohydrate intake, together with the administration of natural bioactive drugs, is assumed to have a protective effect in the prevention and amelioration of the metabolic syndrome (MetS). The aim of the study was to evaluate effects of diet improvement and/or a phenolic compound (rosmarinic acid; RA) administration (100 mg/kg per d) on metabolic as well as functional changes of vessels and hippocampus caused by the MetS-like conditions. The MetS-like conditions were induced by a high-fat-fructose diet (HFFD) in Prague hereditary hypertriacylglycerolaemic (HTG) rats. The effect of diet improvement and RA administration was studied using biochemical and functional measurements. Consumption of HFFD by HTG rats resulted in the development of conditions like the MetS. The fat and fructose restriction from the diet led to amelioration of basic indicators of metabolic state in rats fed HFFD and to amendment parameters of glucose tolerance test and reduction of the IL-1β serum levels. Moreover, aortic endothelial function was improved with an impact on blood pressure. The functional measurement of electrophysiology of the hippocampus showed that long-term potentiation of neuronal transmission course deteriorated after HFFD was improved by energy restriction. Oral administration of RA had a supporting effect not only on lipid and glucose metabolism but also on the vascular endothelium. Combination of both types of therapy induced beneficial effect on glucose tolerance and lipid peroxidation. Thus, combined improvement of diet habits and treatment with natural bioactive drugs is assumed to have protective effect in prevention and amelioration of the MetS.

A Review of the Anti-Inflammatory Effects of Rosmarinic Acid on Inflammatory Diseases

Inflammatory diseases are caused by abnormal immune responses and are characterized by an imbalance of inflammatory mediators and cells. In recent years, the anti-inflammatory activity of natural products has attracted wide attention. Rosmarinic acid (RosA) is a water-soluble phenolic compound that is an ester of caffeic acid and 3, 4-dihydroxyphenyl lactic acid. It is discovered in many plants, like those of the Boraginaceae and Lamiaceae families. RosA has a wide range of pharmacological effects, including anti-oxidative, anti-apoptotic, anti-tumorigenic, and anti-inflammatory effects. The anti-inflammatory effects of RosA have been revealed through in vitro and in vivo studies of various inflammatory diseases like arthritis, colitis, and atopic dermatitis. This article mainly describes the preclinical research of RosA on inflammatory diseases and depicts a small amount of clinical research data. The purpose of this review is to discuss the anti-inflammatory effects of RosA in inflammatory diseases and its underlying mechanism.

Protective Effect and Mechanism of Action of Rosmarinic Acid on Radiation-Induced Parotid Gland Injury in Rats

The parotid glands are damaged by oxidative stress and a series of pathophysiological changes after irradiation. Rosmarinic acid (RA) is a natural antioxidant that provides a radioprotective effect against harmful damage from ionizing radiation. The present study aims to explore the protective effects of RA on radiation-induced parotid gland injury and its underlying mechanism. Sprague-Dawley rats were irradiated with 15 Gy X-ray and treated with different concentrations of RA (30, 60, and 120 mg/kg) or amifostine (AMI, 250 mg/kg). Saliva secretion function, oxidative stress, apoptosis, the inflammatory response, and fibrosis were determined by the measurement of the salivary flow rate, enzyme-linked immunosorbent assay, transferase-mediated DUTP Nick end labeling, Western blot, quantitative real time polymerase chain reaction, and hematoxylin and eosin staining. Here, we show that RA treatment significantly attenuated reactive oxygen species by a direct hindrance effect and the indirect activation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha/nicotinamide adenine dinucleotide phosphate oxidase 4 signaling. Rosmarinic acid not only reduced apoptosis by inhibiting p53/jun N-terminal kinase activation but also reduced parotid gland tissue fibrosis by downregulating inflammatory factor levels. Compared to AMI, RA has the obvious advantages of late efficacy and convenient usage. Moreover, 60 mg/kg is the minimum effective dose of RA. Therefore, RA can potentially be applied as a therapeutic radioprotective agent to treat radiation-induced parotid gland injury in the future.

Antihypertensive phytocomplexes of proven efficacy and well-established use: Mode of action and individual characterization of the active constituents

Hypertension has become the leading risk factor for worldwide cardiovascular diseases. Conventional pharmacological treatment, after both dietary and lifestyle changes, is generally proposed. In this review, we present the antihypertensive properties of phytocomplexes from thirteen plants, long ago widely employed in ethnomedicines and, in recent years, increasingly evaluated for their activity in vitro and in vivo, also in humans, in comparison with synthetic drugs acting on the same systems. Here, we focus on the demonstrated or proposed mechanisms of action of such phytocomplexes and of their constituents proven to exert cardiovascular effects. Almost seventy phytochemicals are described and scientifically sound pertinent literature, published up to now, is summarized. The review emphasizes the therapeutic potential of these natural substances in the treatment of the 'high normal blood pressure' or 'stage 1 hypertension', so-named according to the most recent European and U.S. guidelines, and as a supplementation in more advanced stages of hypertension, however needing further validation by clinical trial intensification.

The detailed biological investigations about combined effects of novel polyphenolic and photo-plasmonic nanoparticles loaded graphene nanosheets on coronary endothelial cells and isolated rat aortic rings

In this study, the effect of Polyp-Au-GO nanocomposite on VSMC proliferation, cell cycle proteins, down-regulation of mRNA in the rat was tested. Briefly, Polyp-Au-GO composite material was synthesized and characterized by UV-Vis spectra, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Polyp-Au-GO composite exhibited the absorbance peak at 530 nm. XRD analysis confirmed the crystalline particle with size ranging between 16.5 and 32.6 nm. The crystallinity differences of the nanocomposite were examined by Raman spectroscopy analysis. The presence of a strong band (1500 cm^-1) and the absence of other lower frequency bands confirmed that the absence of crystallinity of Polyp-Au-GO nanocomposite. The thermal properties of Polyp-Au-GO nanocomposite were determined by TGA analysis. The results revealed that 15% of its weight loss has occurred at 300 °C. Further, the growth of VSMCs was inhibited by the treatment of Polyp-Au-GO composite at 72 h. The IC₅₀ value was registered at 0.57 μg/mL. Additionally, the Polyp-Au-GO composite arrest G1 cell cycle and down-regulated cell cycle proteins. These Polyp-Au-GO composite also reduced the extracellular ERK1/2 phosphorylation. Furthermore, Polyp-Au-GO composite inhibited TNF-R-evoked inflammatory responses. Moreover, Polyp-Au-GO composite inhibited of CEC proliferation. These results suggest that Polyp-Au-GO composite inhibits VSMC proliferation and TNF-R-mediated inflammatory responses. This study suggested the therapeutic role of Polyp-Au-GO composite in cardiovascular disease.

Therapeutic Potential of Rosmarinic Acid: A Comprehensive Review

Naturally occurring food-derived active ingredients have received huge attention for their chemopreventive and chemotherapy capabilities in several diseases. Rosmarinic acid (RA) is a caffeic acid ester and a naturally-occurring phenolic compound in a number of plants belonging to the Lamiaceae family, such as Rosmarinus officinalis (rosemary) from which it was formerly isolated. RA intervenes in carcinogenesis through different ways, including in tumor cell proliferation, apoptosis, metastasis, and inflammation. On the other hand, it also exerts powerful antimicrobial, anti-inflammatory, antioxidant and even antidepressant, anti-aging effects. The present review aims to provide an overview on anticancer activities of RA and to deliberate its therapeutic potential against a wide variety of diseases. Given the current evidence, RA may be considered as part of the daily diet in the treatment of several diseases, with pre-determined doses avoiding cytotoxicity.

Rosmarinic inhibits cell proliferation, invasion and migration via up-regulating miR-506 and suppressing MMP2/16 expression in pancreatic cancer

Pancreatic cancer is the fourth leading cause of cancer-related deaths worldwide. However, therapeutic strategies for the treatment of pancreatic cancer are still limited. Therefore, it is urgent for us to develop novel effective therapies for pancreatic cancer. In this study, we explored the effects of rosmarinic acid on pancreatic progression and explored the underlying molecular mechanisms. Rosmarinic acid significantly suppressed cell viability, cell growth, cell invasion and migration as well as epithelial mesenchymal transition (EMT) of pancreatic cancer cells, and induced cell apoptosis in pancreatic cells. In addition, rosmarinic acid significantly up-regulated the expression of miR-506 in pancreatic cancer cells, and knockdown of miR-506 attenuated the suppressive effects of rosmarinic acid on cell growth, cell invasion and migration and EMT, and prevented the enhanced effects of rosmarinic acid on cell apoptosis in pancreatic cancer cells. Mechanistically, the luciferase reporter assay showed that miR-506 targeted the 3' untranslated region of matrix metalloproteinase (MMP)-2/16, and miR-506 overexpression and rosmarinic acid treatment suppressed the expression of MMP2/16 in pancreatic cancer cells. Overexpression of MMP2/16 attenuated the inhibitory effects of rosmarinic acid on pancreatic cell invasion and migration. In vivo studies showed that rosmarinic acid dose-dependently suppressed tumor growth of pancreatic cancer cells, and increased the expression of miR-506, while suppressed the expression of MMP2/16 and Ki-67 in dissected tumor tissues from xenograft nude mice. Collectively, our results for the first time revealed the anti-tumor effects of rosmarinic acid in pancreatic cancer, and the anti-tumor effects of rosmarinic acid were via regulating the miR-506/MMP2/16 axis in pancreatic cancer.

Derivatization of Rosmarinic Acid Enhances its in vitro Antitumor, Antimicrobial and Antiprotozoal Properties

On its own, rosmarinic acid possesses multiple biological activities such as anti-inflammatory, antimicrobial, cardioprotective and antitumor properties, and these are the consequence of its ROS scavenging and inhibitory effect on inflammation. In this study, two quaternary phosphonium salts of rosmarinic acid were prepared for the purpose of increasing its penetration into biological systems with the aim of improving its antimicrobial, antifungal, antiprotozoal and antitumor activity. The synthetized molecules, the triphenylphosphonium and tricyclohexylphosphonium salts of rosmarinic acid, exhibited significantly stronger inhibitory effects on the growth of HCT116 cells with IC50 values of 7.28 or 8.13 μM in comparison to the initial substance, rosmarinic acid (>300 μM). For the synthesized derivatives, we detected a greater than three-fold increase of activity against Acanthamoeba quina, and a greater than eight-fold increase of activity against A. lugdunensis in comparison to rosmarinic acid. Furthermore, we recorded significantly higher antimicrobial activity of the synthetized derivatives when compared to rosmarinic acid itself. Both synthetized quaternary phosphonium salts of rosmarinic acid appear to be promising antitumor and antimicrobial agents, as well as impressive molecules for further research.

Ethyl Rosmarinate Protects High Glucose-Induced Injury in Human Endothelial Cells

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and explored its underlying mechanisms. Our results showed that both RAE and rosmarinic acid (RA) increased cell viability, decreased the production of reactive oxygen species (ROS), and attenuated high glucose-induced endothelial cells apoptosis in a dose-dependent manner, as evidenced by Hochest staining, Annexin V⁻FITC/PI double staining, and caspase-3 activity. RAE and RA both elevated Bcl-2 expression and reduced Bax expression, according to Western blot. We also found that LY294002 (phosphatidylinositol 3-kinase, or PI3K inhibitor) weakened the protective effect of RAE. In addition, PDTC (nuclear factor-κB, or NF-κB inhibitor) and SP600125 (c-Jun N-terminal kinase, or JNK inhibitor) could inhibit the apoptosis in endothelial cells caused by high glucose. Further, we demonstrated that RAE activated Akt, and the molecular docking analysis predicted that RAE showed more affinity with Akt than RA. Moreover, we found that RAE inhibited the activation of NF-κB and JNK. These results suggested that RAE protected endothelial cells from high glucose-induced apoptosis by alleviating reactive oxygen species (ROS) generation, and regulating the PI3K/Akt/Bcl-2 pathway, the NF-κB pathway, and the JNK pathway. In general, RAE showed greater potency than RA equivalent.

Rosmarinic Acid, a Component of Rosemary Tea, Induced the Cell Cycle Arrest and Apoptosis through Modulation of HDAC2 Expression in Prostate Cancer Cell Lines

Rosmarinic acid (RA), a main phenolic compound contained in rosemary which is used as tea, oil, medicine and so on, has been known to present anti-inflammatory, anti-oxidant and anti-cancer effects. Histone deacetylases (HDACs) are enzymes that play important roles in gene expression by removing the acetyl group from histone. The aberrant expression of HDAC in human tumors is related with the onset of human cancer. Especially, HDAC2, which belongs to HDAC class I composed of HDAC 1, 2, 3 and 8, has been reported to be highly expressed in prostate cancer (PCa) where it downregulates the expression of p53, resulting in an inhibition of apoptosis. The purpose of this study is to investigate the effect of RA in comparison with suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor used as an anti-cancer agent, on survival and apoptosis of PCa cell lines, PC-3 and DU145, and the expression of HDAC. RA decreased the cell proliferation in cell viability assay, and inhibited the colony formation and tumor spheroid formation. Additionally, RA induced early- and late-stage apoptosis of PC-3 and DU145 cells in Annexin V assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. In western blot analysis, RA inhibited the expression of HDAC2, as SAHA did. Proliferating cell nuclear antigen (PCNA), cyclin D1 and cyclin E1 were downregulated by RA, whereas p21 was upregulated. In addition, RA modulated the protein expression of intrinsic mitochondrial apoptotic pathway-related genes, such as Bax, Bcl-2, caspase-3 and poly (ADP-ribose) polymerase 1 (PARP-1) (cleaved) via the upregulation of p53 derived from HDAC2 downregulation, leading to the increased apoptosis of PC-3 and DU145 cells. Taken together, treatment of RA to PCa cell lines inhibits the cell survival and induces cell apoptosis, and it can be used as a novel therapeutic agent toward PCa.

Streptozotocin-induced diabetes in rats: effects of White Butterfly (Clerodendrum volubile) leaves on blood glucose levels, lipid profile and antioxidant status

White Butterfly (Clerodendrum volubile) leaf is commonly used in traditional medicine for the management of various diseases including diabetes without the full understanding of the scientific basis for its use. This study sought to evaluate the antihyperglycemic, antihyperlipidemic and antioxidant effect of C. volubile leaves in streptozotocin (STZ)-induced diabetic rats. Aqueous extract of C. volubile was prepared and its effect assessed on relevant enzymes associated with diabetes. Fifty male Wistar rats were randomly separated into 10 groups each containing five rats. The induction of diabetes in rats was by a single intraperitoneal injection of STZ (65 mg/kg body weight) while C. volubile extract was administered orally to diabetic and non-diabetic animals, at the doses of 50, 100 and 200 mg/kg body weight for 14 days. Metformin (100 mg/kg body weight) served as positive control. Clerodendrum volubile extract inhibited α-glucosidase (IC₅₀ = 0.20 mg/ml) and α-amylase (IC₅₀ = 0.58 mg/ml). Furthermore, administration of C. volubile extract significantly reduced the elevated plasma glucose level and body weight, improved kidney functions, attenuated oxidative stress by decreasing MDA levels, enhancing superoxide dismutase, catalase and glutathione peroxidase activities, reinstated the lipid profile to nearly normal level and restored pancreatic histological integrity in diabetic rats. The results reveal that C. volubile represents a source of phytochemicals that exerts their antidiabetic effects through the modulation of glycemic and atherogenic indices as well as mitigation of free-radical-mediated damage.

Methylene blue alleviates endothelial dysfunction and reduces oxidative stress in aortas from diabetic rats

Endothelial dysfunction and the related increase in reactive oxygen species (ROS) production are important events in the pathophysiology of diabetes mellitus (DM). Methylene blue (MB) has been systematically investigated for its protective effects against refractory hypotension and mitochondrial dysfunction. We have previously demonstrated that MB improved mitochondrial respiration and partially decreased oxidative stress in diabetic rat hearts. The present study was aimed to investigate whether MB modulates vascular function and ROS production in thoracic aortic rings isolated from rats with streptozotocin-induced DM (after 4 weeks of hyperglycemia). The effects of MB (0.1 μM, 30 min ex vivo incubation) on vascular reactivity in organ chamber (phenylephrine-induced contraction, acetylcholine-induced relaxation) and H₂O₂ production (assessed by ferrous iron xylenol orange oxidation assay) were investigated in vascular preparations with intact endothelium and after denudation. DM elicited a significant alteration of vascular function: increased contractility to phenylephrine, attenuation of acetylcholine-dependent relaxation, and augmented H₂O₂ generation. Ex vivo incubation with MB partially reversed all these changes (by approximately 70%) in vascular segments with intact endothelial layer (but not in denuded vessels). In conclusion, MB might be useful in alleviating endothelial dysfunction and mitigating endothelial oxidative stress, observations that clearly require further investigation in the setting of cardiometabolic disease.

Effect of curcumin on bone tissue in the diabetic rat: repair of peri-implant and critical-sized defects

This study determined the effect of curcumin on bone healing in animals with diabetes mellitus (DM). One hundred rats were divided into five groups: DM+PLAC, DM+CURC, DM+INS, DM+CURC+INS, and non-DM (CURC, curcumin; PLAC, placebo; INS, insulin). Critical calvarial defects were created and titanium implants were inserted into the tibiae. Calvarial defects were analyzed histometrically, and BMP-2, OPN, OPG, RANKL, Runx2, Osx, β-catenin, Lrp-5, and Dkk1 mRNA levels were quantified by PCR. The implants were removed for a torque evaluation, the peri-implant tissue was collected for mRNA quantification of the same bone-related markers, and the tibiae were submitted to micro-computed tomography. The DM+CURC+INS and non-DM groups exhibited greater closure of the calvaria when compared to the DM+PLAC group (P<0.05). Increased retention of implants was observed in the DM+CURC, DM+CURC+INS, and non-DM groups when compared to the DM+PLAC group (P<0.05). CURC improved bone volume and increased bone-implant contact when compared to DM+PLAC (P<0.05). In calvarial samples, CURC favourably modulated RANKL/OPG and Dkk1 and improved β-catenin levels when compared to DM+PLAC (P<0.05). In peri-implant samples, Dkk1 and RANKL/OPG were down-regulated and BMP-2 up-regulated by CURC when compared to DM+PLAC (P<0.05). CURC reverses the harmful effects of DM in bone healing, contributing to the modulation of bone-related markers.

Pharmacokinetic Assessments of Liquiritin, Protocatechuic Aldehyde and Rosmarinic Acid in Rat Plasma by UPLC-MS-MS After Administration of ZibuPiyin Recipe

The three analytes of the Traditional Chinese Medicine ZibuPiyin Recipe (ZBPYR), namely, liquiritin, protocatechuic aldehyde and rosmarinic acid, may synergistically play an important role in regulating memory and learning. However, the pharmacokinetic behaviors of these compounds after their co-administration remain unclear. To this end, a selective and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated in rat plasma for the study of these three major bioactive ingredients in ZBPYR. The analytes in the plasma samples were separated on a Shiseido Capcell core C18 column using bendrofluazide as an internal standard, with a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. Electrospray ionization in the negative-ion mode and multiple reaction monitoring were used to identify and quantify the three analytes. All of the calibration curves showed good linearity (r > 0.992) over the concentration range, with a lower limit of quantification of 5 ng/mL. The precision of the analytical method was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation (SD) was within 15%. Satisfactory extraction efficiency (between 83.4 and 99.4%) and matrix effects (76.4-107.4) were obtained by liquid-liquid extraction. The pharmacokinetic results showed that the three bioactive ingredients were rapidly absorbed and had a short terminal half-life in rats after oral administration of ZibuPiyin recipe. This UPLC-MS-MS study method used in this study may be useful for assessing the pharmacokinetic characteristics of various compounds, which would be helpful in determining their clinical potential.

Rosmarinic acid: modes of action, medicinal values and health benefits

The supplementation of livestock rations with herbs containing bioactive components, such as rosmarinic acid (RA), have shown promising results as a natural feed additive in promoting growth, productive and reproductive performance, feed utilization, fertility, anti-oxidant status and immunologic indices. Furthermore, RA reportedly reduces the risks of various animal diseases and mitigates side effects of chemical and synthetic drugs. RA is a natural polyphenol present in several Lamiaceae herbs like Perilla frutescens, and RA is becoming an integral component of animal nutrition as it counters the effect of reactive oxygen species induced in the body as a consequence of different kinds of stressors. Studies have further ascertained the capability of RA to work as an anti-microbial, immunomodulatory, anti-diabetic, anti-allergic, anti-inflammatory, hepato- and renal-protectant agent, as well as to have beneficial effects during skin afflictions. Additionally, RA is favored in meat industries due to enhancing the quality of meat products by reportedly improving shelf-life and imparting desirable flavor. This review describes the beneficial applications and recent findings with RA, including its natural sources, modes of action and various useful applications in safeguarding livestock health as well as important aspects of human health.

The anti-inflammatory and anti-glycative effects of rosmarinic acid in the livers of type 1 diabetic mice

Background: Rosmarinic acid (RA) is a polyphenol present in members of the Lamiaceae family. In this study, yhe anti-inflammatory and anti-glycative effects of RA in the livers of type 1 diabetic mice were examined.

Methods: The diabetic mice were divided into three groups: diabetic mice with 0, low dose RA (25 mg/ml), and high dose RA (50 mg/ml). One group of non-diabetic mice was used as a control for comparison. RA was supplied via daily 200 μL oral injections for 9 weeks. The level of interleukin (IL)-6, the tumor necrosis factor (TNF)-alpha, the prostaglandin E₂ (PGE₂), and the activity of cyclooxygenase (COX)-2 in the livers were measured. The hepatic receptor of advanced glycative endproduct (RAGE), the sorbitol levels, and the glyoxalase 1 (GLO-1) activity were also determined.

Results: Compared with diabetic group that received no RA, the groups with RA supplements at both levels of dosages had increased body weight and had both decreased water intake and feed intake (p < 0.05). RA intake was found to reduce plasma glucose level and elevate plasma insulin level when compared with the diabetic group that received no RA (p < 0.05). RA treatments lowered the hepatic level of IL-6, TNF-alpha, and PGE₂, as well as the activity of COX-2 (p < 0.05). RA administration also decreased hepatic RAGE and sorbitol levels, and GLO-1 activity when compared with the diabetic group that received no RA (P < 0.05).

Conclusion: These findings support the conclusion that rosmarinic acid (RA) could be a potent protective agent for the liver against diabetic injury.

Rosmarinic Acid Alleviates the Endothelial Dysfunction Induced by Hydrogen Peroxide in Rat Aortic Rings via Activation of AMPK

Endothelial dysfunction is the key player in the development and progression of vascular events. Oxidative stress is involved in endothelial injury. Rosmarinic acid (RA) is a natural polyphenol with antioxidative, antiapoptotic, and anti-inflammatory properties. The present study investigates the protective effect of RA on endothelial dysfunction induced by hydrogen peroxide (H2O2). Compared with endothelium-denuded aortic rings, the endothelium significantly alleviated the decrease of vasoconstrictive reactivity to PE and KCl induced by H2O2. H2O2 pretreatment significantly injured the vasodilative reactivity to ACh in endothelium-intact aortic rings in a concentration-dependent manner. RA individual pretreatment had no obvious effect on the vasoconstrictive reaction to PE and KCl, while its cotreatment obviously mitigated the endothelium-dependent relaxation impairments and the oxidative stress induced by H2O2. The RA cotreatment reversed the downregulation of AMPK and eNOS phosphorylation induced by H2O2 in HAEC cells. The pretreatment with the inhibitors of AMPK (compound C) and eNOS (L-NAME) wiped off RA's beneficial effects. All these results demonstrated that RA attenuated the endothelial dysfunction induced by oxidative stress by activating the AMPK/eNOS pathway.

Effect of Resveratrol on Critical-Sized Calvarial Defects of Diabetic Rats: Histometric and Gene Expression Analysis

PURPOSE

This study investigated the influence of resveratrol (RESV) on the repair of bone critical defects in calvaria of animals with induced diabetes mellitus (DM).

MATERIAL AND METHODS

One hundred rats were divided into 5 groups: induced DM + RESV administration (DM + RESV; n = 20); induced DM plus placebo solution administration (DM + PLAC; n = 20); induced DM plus insulin therapy (DM + INS; n = 20); induced DM plus administration of RES and INS (DM + RESV + INS; n = 20); and nondiabetic controls (NDM; n = 20). DM was induced by intraperitoneal injection of streptozotocin 50 mg/kg 3 days before the surgical procedures. Two critical calvarial defects were created in each animal at the start of the study (day 0). Treatments were administered from day 0 to day 30 of the experiment, when animals were euthanized. One defect was processed for histometric analysis to measure closure of the bone defect. The tissue of the other defect was analyzed for quantification of bone morphogenetic protein-2 (BMP-2), osteopontin, osteoprotegerin, receptor activator of nuclear factor-κB ligand, runt-related transcription factor-2, osterix (Osx), β-catenin, lipoprotein receptor-related protein-5, and dikkop-1 mRNA by quantitative polymerase chain reaction.

RESULTS

Histometric results showed that the DM + RESV, DM + RESV + INS, and NDM groups exhibited greater closure of the bone defects compared with the PLAC- or INS-treated groups (P < .05). Diabetic animals treated with RESV plus INS showed higher levels of BMP-2 and Osx; Osx also was positively increased in animals treated with INS alone (P < .05).

CONCLUSIONS

The use of RESV, regardless of the presence of INS, positively influenced bone repair in animals with induced DM. Further, the combination of INS plus RESV was necessary for the modulation of BMP-2 gene expression.

Rosmarinic acid suppresses adipogenesis, lipolysis in 3T3-L1 adipocytes, lipopolysaccharide-stimulated tumor necrosis factor-α secretion in macrophages, and inflammatory mediators in 3T3-L1 adipocytes

Background: Rosmarinic acid (RA) is a natural phenol carboxylic acid with many promising biological effects. It may be a suitable candidate for improving obesity-related adipose tissue dysfunction.

Objective: We aimed to investigate the therapeutic use of RA as an anti-obesity agent by measuring its effects on adipogenesis, lipolysis, and messenger RNA (mRNA) expression of major adipokines in 3T3-L1 adipocytes; and its effects on lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) secretion in macrophages and inflammatory mediators in 3T3-L1 adipocytes incubated with macrophage-conditioned medium (MCM).

Methods: 3T3-L1 preadipocytes were used to explore how RA affects adipogenesis, as well as the involvement of phosphorylated extracellular signal-regulated kinase-1/2 (p-ERK1/2) and mothers against decapentaplegic homolog 3 (p-Smad3). 3T3-L1 preadipocytes were also differentiated into mature adipocytes to explore how RA affects basal and isoproterenol- and forskolin-stimulated lipolysis; and how RA affects key adipokines’ mRNA expression. RAW 264.7 macrophages were stimulated with LPS in the absence or presence of RA to explore RA’s effects on TNF-α secretion. MCM was collected and 3T3-L1 adipocytes were incubated with MCM to explore RA’s effects on interleukin-6 (IL-6), IL-1β, monocyte chemoattractant protein-1 (MCP-1), and RANTES mRNA expression.

Results: During the preadipocyte differentiation process, RA suppressed peroxisome proliferator-activated receptor-γ and CCAAT/enhancer binding protein-α, and activated p-ERK1/2 and p-Smad3; inhibition of adipogenesis by RA was partially restored following treatment with p-ERK1/2 and p-Smad3 inhibitors. In mature adipocytes, RA inhibited basal lipolysis; phosphodiesterase-3 inhibitor reversed this. RA also inhibited isoproterenol- and forskolin-stimulated glycerol and free fatty acid release, and the phosphorylation of hormone-sensitive lipase and perilipin. RA had no effects on leptin, adiponectin, resistin, or visfatin mRNA expression. RA suppressed TNF-α mRNA expression and secretion in LPS-stimulated RAW 264.7 macrophages; and reduced LPS-MCM-induced IL-6, IL-1β, MCP-1, and RANTES mRNA expression in 3T3-L1 adipocytes.

Conclusions: RA exerts inhibitory effects on adipogenesis, lipolysis, and inflammation. RA could be a promising natural product for improving adipose mobilization in obesity.

Hypertriglyceridemic rats fed high fat diet as a model of metabolic syndrome

People with metabolic syndrome have higher risk of cardiovascular diseases then those without. The aim of the work was to investigate whether high fat diet administered to Prague hereditary hypertriglyceridemic (HTG) rats can induce signs of metabolic syndrome (MetS). Our results showed that HTG rats fed high fat diet (HTGch) had disturbed glucose metabolism and also lipid metabolism - increased serum triacylglycerols (TAG), total cholesterol (Ch), low-density lipoprotein-Ch (LDL-Ch), and decreased high-density lipoprotein-Ch (HDL-Ch). Their livers proved markers of developing steatosis. Moreover, HTGch had increased blood pressure, yet the vascular endothelium was not significantly damaged. All these changes were accompanied with oxidative stress and tissue damage identified as increased liver concentrations of thiobarbituric acid reactive substances (TBARS) and activity of the lysosomal enzyme N-acetyl-D-glucosaminidase (NAGA). We assume that the model used may be suitable for the study of MetS with no evidence of obesity. Prolongation of the high fat diet duration might have a major impact on all parameters tested, especially on vascular endothelial function.

Main constituents of polyphenol complex from seagrasses of the genus Zostera, their antidiabetic properties and mechanisms of action

The present review analyzed the recent experimental studies of the alleviating activity of main constituents of the polyphenol complex from seagrasses of the genus Zostera, namely rosmarinic acid, luteolin and its sulfated derivatives, on carbohydrate and lipid metabolism disorders. A number of studies by our group and others, in which various experimental models of diabetes and hyperlipidemia were used, show a therapeutic action of the polyphenol complex and the abovementioned phenolic constituents, when applied separately and in combination. Based on the analysis of the results of these studies, the probable mechanisms of the therapeutic action of these compounds in diabetes and hyperlipidemia were proposed.

Anti-Warburg effect of rosmarinic acid via miR-155 in colorectal carcinoma cells

The Warburg effect, glycolytic production of ATP under aerobic conditions, is found to be a universal feature of most cancer cells. Our study was aimed to determine whether rosmarinic acid (RA) had the anti-Warburg effect activity against colorectal carcinoma. Furthermore, the mechanism for the anti-Warburg effect by RA would be investigated. In our study, we found that RA suppressed glucose consumption and lactate generation in colorectal carcinoma cells; meanwhile, RA inhibited the expression of transcription factor hypoxia-inducible factor-1α (HIF-1α) that affects the glycolytic pathway. Chronic inflammation is a key promoting factor of the Warburg effect. As we supposed, the present study also showed that RA could not only repress proinflammatory cytokines using enzyme-linked immunosorbent assay but it could also suppress microRNAs related to inflammation by real-time PCR. Therefore, we proposed that RA may inhibit the Warburg effect by suppressing the inflammatory response of colorectal carcinoma cells. Recent studies have provided evidence that miR-155 was an important mediator between inflammation and carcinogenesis. We further showed that miR-155 acted to repress the Warburg effect through the mechanism of inactivating the IL-6/STAT3 pathway. Above all, RA might be a potential therapeutic agent against colorectal carcinoma.

Rosmarinic acid ameliorates hyperglycemia and insulin sensitivity in diabetic rats, potentially by modulating the expression of PEPCK and GLUT4

BACKGROUND

Rosmarinic acid (RA) is a natural substance that may be useful for treating diabetes mellitus. The present study investigated the effects of RA on glucose homeostasis and insulin regulation in rats with streptozocin (STZ)-induced type 1 diabetes or high-fat diet (HFD)-induced type 2 diabetes.

METHODS

Glucose homeostasis was determined using oral glucose tolerance tests and postprandial glucose tests, and insulin activity was evaluated using insulin tolerance tests and the homeostatic model assessment for insulin resistance. Additionally, the protein expression levels of PEPCK and GLUT4 were determined using Western blot analysis.

RESULTS

RA administration exerted a marked hypoglycemic effect on STZ-induced diabetic rats and enhanced glucose utilization and insulin sensitivity in HFD-fed diabetic rats. These effects of RA were dose-dependent. Meanwhile, RA administration reversed the STZ- and HFD-induced increase in PEPCK expression in the liver and the STZ- and HFD-induced decrease in GLUT4 expression in skeletal muscle.

CONCLUSION

RA reduces hyperglycemia and ameliorates insulin sensitivity by decreasing PEPCK expression and increasing GLUT4 expression.

Protective effects of rosmarinic acid against radiation-induced damage to the hematopoietic system in mice

Rosmarinic acid (RA) is an ester of caffeic acid and 3, 4-dihydroxyphenyl lactic acid. It is a potent antioxidant that functions by scavenging free radicals. Here, we used a 30-day survival assay to investigate the radioprotective effects of RA. Mice were treated with RA once per day for 10 consecutive days starting at 3 days before gamma irradiation at 7.5 Gy until 7 days post irradiation. Mice treated with 100 and 200 mg/kg body weight (bw) of RA had 30-day survival rates of 89% and 72%, respectively, compared with 32% in the control group, and the differences were statistically significant (P = 0.0008 and 0.0421, respectively). Spleen colony-forming units (CFU-S), the number of nucleated cells in the bone marrow (BMNC), bone marrow DNA content, and hematological parameters of the peripheral blood were measured to investigate the radioprotective effect of RA on the hematopoietic system. The treatment groups that received RA at 50, 100 and 150 mg/kg bw and whole-body exposure to 5.5 Gy of (137)Cs γ- radiation had significantly higher CFU-S, BMNC and DNA content than the irradiation-only group. Assessment of hematological parameters in the peripheral blood showed that the treatment groups receiving RA at doses of 50, 100 and 150 mg/kg bw had higher white blood cell counts, hemoglobin and platelets than the radiation-only group. These results suggested that the administration of RA promoted the recovery of peripheral blood cells in irradiated mice.

[Biological activity and mechanisms of therapeutic action of rosmarinic acid, luteolin and its sulphated derivatives]

The review considers recent experimental studies of biological activity and mechanisms of therapeutic action of rosmarinic acid, luteolin and its sulfated derivatives in diseases associated with disorders of carbohydrate and lipid metabolism. Particular attention is focused on the results of studies showing a high therapeutic potential of these phenolic compounds in their prophylactic and therapeutic use at experimental modeling of type 2 diabetes and hyperlipidemia. Based on the analysis of our results and the literature data putative mechanisms of therapeutic action of rosmarinic acid, luteolin and its sulfated derivatives have been proposed.

Antidiabetic Effects of Simple Phenolic Acids: A Comprehensive Review

Diabetes mellitus (DM) has become a major public health threat across the globe. Current antidiabetic therapies are based on synthetic drugs that very often have side effects. It has been widely acknowledged that diet plays an important role in the management of diabetes. Phenolic acids are widely found in daily foods such as fruits, vegetables, cereals, legumes, and wine and they provide biological, medicinal, and health properties. Simple phenolic acids have been shown to increase glucose uptake and glycogen synthesis, improve glucose and lipid profiles of certain diseases (obesity, cardiovascular diseases, DM, and its complication). The current review is an attempt to list out the antidiabetic effects of simple phenolic acids from medicinal plants and botanical foods.

Protective effect of rosmarinic acid against oxidative stress biomarkers in liver and kidney of strepotozotocin-induced diabetic rats

In the present study, we investigated the efficiency of rosmarinic acid (RA) in preventing the alteration of oxidative parameters in the liver and kidney of diabetic rats induced by streptozotocin (STZ). The animals were divided into six groups (n = 8): control, ethanol, RA 10 mg/kg, diabetic, diabetic/ethanol, and diabetic/RA 10 mg/kg. After 3 weeks of treatment, we found that TBARS levels in liver and kidney were significantly increased in the diabetic/saline group and the administration of RA prevented this increase in the liver and kidney (P < 0.05). Diabetes caused a significant decrease in the activity of superoxide dismutase (SOD) and catalase (CAT) in the diabetes/saline group (P < 0.05). However, the treatment with 10 mg/kg RA (antioxidant) prevented this alteration in SOD and CAT activity in the diabetic RA group (P < 0.05). In addition, RA reverses the decrease in ascorbic acid and non-protein-thiol (NPSH) levels in diabetic rats. The treatment with RA also prevented the decrease in the Delta-aminolevulinic acid dehydratase (ALA-D) activity in the liver and kidney of diabetic rats. Furthermore, RA did not have any effect on glycemic levels. These results indicate that RA effectively reduced the oxidative stress induced by STZ, suggesting that RA is a potential candidate for the prevention and treatment of pathological conditions in diabetic models.

Ethyl rosmarinate relaxes rat aorta by an endothelium-independent pathway

Ethyl rosmarinate is an ester derivative of rosmarinic acid, a major constituent of Hyptis suaveolens. The present study investigated the vasorelaxant mechanism of ethyl rosmarinate in isolated rat aortic rings using an organ bath system. Ethyl rosmarinate (0.1 µM-3mM) produced concentration-dependent relaxation in aortic rings pre-contracted with phenylephrine (10 µM), exhibiting a pD2 value of 4.56 ± 0.08 and an Emax value of 93.82 ± 5.00% (in endothelium-intact rings), as well as a pD2 value of 4.42 ± 0.05 and an Emax value of 92.10 ± 3.78% (in endothelium-denuded rings). In the endothelium-denuded rings, the vasorelaxant effect of ethyl rosmarinate was reduced by only 4-aminopyridine (1mM); however, this was not the case with tetraethylammonium (5mM), glibenclamide (10 µM), barium chloride (1mM), and 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ, 1 µM). Ethyl rosmarinate also reduced the contraction induced by phenylephrine (10 µM) and caffeine (20mM) in a Ca(2+)-free solution, and inhibited the contraction induced by increasing extracellular Ca(2+) influx, which was induced by KCl (80 mM). Ethyl rosmarinate (10 µM) inhibits concentration-response curves for phenylephrine, while in the same concentration of ethyl rosmarinate has no effect on contractions induced by increasing concentrations of calcium in the presence of high extracellular potassium. Our results suggests that ethyl rosmarinate induces relaxation in aortic rings via an endothelium-independent pathway, which involves the opening of voltage-gated potassium (Kv) channels and the blockade of both Ca(2+)release from intracellular stores and extracellular Ca(2+) influx. Moreover, ethyl-rosmarinate acts on the extracellular Ca(2+) influx inhibition by interacting with voltage-operated calcium channels (VOCCs) and receptor-operated calcium channels (ROCCs).