Pomegranate juice polyphenols induce a phenotypic switch in macrophage polarization favoring a M2 anti-inflammatory state

Polyphenols: Role in Modulating Immune Function and Obesity

Polyphenols, long-used components of medicinal plants, have drawn great interest in recent years as potential therapeutic agents because of their safety, efficacy, and wide range of biological effects. Approximately 75% of the world's population still use plant-based medicinal compounds, indicating the ongoing significance of phytochemicals for human health. This study emphasizes the growing body of research investigating the anti-adipogenic and anti-obesity functions of polyphenols. The functions of polyphenols, including phenylpropanoids, flavonoids, terpenoids, alkaloids, glycosides, and phenolic acids, are distinct due to changes in chemical diversity and structural characteristics. This review methodically investigates the mechanisms by which naturally occurring polyphenols mediate obesity and metabolic function in immunomodulation. To this end, hormonal control of hunger has the potential to inhibit pro-obesity enzymes such as pancreatic lipase, the promotion of energy expenditure, and the modulation of adipocytokine production. Specifically, polyphenols affect insulin, a hormone that is essential for regulating blood sugar, and they also play a role, in part, in a complex web of factors that affect the progression of obesity. This review also explores the immunomodulatory properties of polyphenols, providing insight into their ability to improve immune function and the effects of polyphenols on gut health, improving the number of commensal bacteria, cytokine production suppression, and immune cell mediation, including natural killer cells and macrophages. Taken together, continuous studies are required to understand the prudent and precise mechanisms underlying polyphenols' therapeutic potential in obesity and immunomodulation. In the interim, this review emphasizes a holistic approach to health and promotes the consumption of a wide range of foods and drinks high in polyphenols. This review lays the groundwork for future developments, indicating that the components of polyphenols and their derivatives may provide the answer to urgent worldwide health issues. This compilation of the body of knowledge paves the way for future discoveries in the global treatment of pressing health concerns in obesity and metabolic diseases.

Lipid-laden foam cells in the pathology of atherosclerosis: shedding light on new therapeutic targets

INTRODUCTION

Lipid-laden foam cells within atherosclerotic plaques are key players in all phases of lesion development including its progression, necrotic core formation, fibrous cap thinning, and eventually plaque rupture. Manipulating foam cell biology is thus an attractive therapeutic strategy at early, middle, and even late stages of atherosclerosis. Traditional therapies have focused on prevention, especially lowering plasma lipid levels. Despite these interventions, atherosclerosis remains a major cause of cardiovascular disease, responsible for the largest numbers of death worldwide.

AREAS COVERED

Foam cells within atherosclerotic plaques are comprised of macrophages, vascular smooth muscle cells, and other cell types which are exposed to high concentrations of lipoproteins accumulating within the subendothelial intimal layer. Macrophage-derived foam cells are particularly well studied and have provided important insights into lipid metabolism and atherogenesis. The contributions of foam cell-based processes are discussed with an emphasis on areas of therapeutic potential and directions for drug development.

EXERT OPINION

As key players in atherosclerosis, foam cells are attractive targets for developing more specific, targeted therapies aimed at resolving atherosclerotic plaques. Recent advances in our understanding of lipid handling within these cells provide insights into how they might be manipulated and clinically translated to better treat atherosclerosis.

Antioxidant Activities of Natural Compounds from Caribbean Plants to Enhance Diabetic Wound Healing

Diabetic wound healing is a global medical challenge. Several studies showed that delayed healing in diabetic patients is multifactorial. Nevertheless, there is evidence that excessive production of ROS and impaired ROS detoxification in diabetes are the main cause of chronic wounds. Indeed, increased ROS promotes the expression and activity of metalloproteinase, resulting in a high proteolytic state in the wound with significant destruction of the extracellular matrix, which leads to a stop in the repair process. In addition, ROS accumulation increases NLRP3 inflammasome activation and macrophage hyperpolarization in the M1 pro-inflammatory phenotype. Oxidative stress increases the activation of NETosis. This leads to an elevated pro-inflammatory state in the wound and prevents the resolution of inflammation, an essential step for wound healing. The use of medicinal plants and natural compounds can improve diabetic wound healing by directly targeting oxidative stress and the transcription factor Nrf2 involved in the antioxidant response or the mechanisms impacted by the elevation of ROS such as NLRP3 inflammasome, the polarization of macrophages, and expression or activation of metalloproteinases. This study of the diabetic pro-healing activity of nine plants found in the Caribbean highlights, more particularly, the role of five polyphenolic compounds. At the end of this review, research perspectives are presented.

Preventive and Therapeutic Effects of Punica granatum L. Polyphenols in Neurological Conditions

Pomegranate (Punica granatum L.) is a polyphenol-rich food and medicinal plant containing flavonols, anthocyanins, and tannins. Ellagitannins (ETs) are the most abundant polyphenols in pomegranate. A growing body of research shows that polyphenol-rich pomegranate extracts and their metabolites target multiple types of brain cell and support their redox balance, proliferation and survival, as well as cell signaling. Independent studies have demonstrated that the significant neuroprotective effects of ETs are mediated by their antioxidant and anti-inflammatory effects, their chelating properties, by their ability to activate various signaling pathways, as well as the ability to influence mitochondrial damage, thus regulating autophagy, apoptosis and neurotransmitter signaling. The multitude of in vitro and in vivo studies summarized in the present review suggest that pomegranate polyphenols act on both neuronal and glial cells directly, and also affect blood-brain barrier function, restoring redox balance in the blood and brain and increasing blood flow to the brain.

Natural products against inflammation and atherosclerosis: Targeting on gut microbiota

The gut microbiota (GM) has become recognized as a crucial element in preserving human fitness and influencing disease consequences. Commensal and pathogenic gut microorganisms are correlated with pathological progress in atherosclerosis (AS). GM may thus be a promising therapeutic target for AS. Natural products with cardioprotective qualities might improve the inflammation of AS by modulating the GM ecosystem, opening new avenues for researches and therapies. However, it is unclear what components of natural products are useful and what the actual mechanisms are. In this review, we have summarized the natural products relieving inflammation of AS by regulating the GM balance and active metabolites produced by GM.

Rhus Coriaria L. Extract: Antioxidant Effect and Modulation of Bioenergetic Capacity in Fibroblasts from Parkinson’s Disease Patients and THP-1 Macrophages

Sumac, Rhus coriaria L., is a Mediterranean plant showing several useful properties, such as antioxidant and neuroprotective effects. Currently, there is no evidence about its possible neuroprotective action in Parkinson’s disease (PD). We hypothesized that sumac could modulate mitochondrial functionality in fibroblasts of familial early-onset PD patients showing PARK2 mutations. Sumac extract volatile profile, polyphenolic content and antioxidant activity have been previously characterized. We evaluated ROS and ATP levels on sumac-treated patients’ and healthy control fibroblasts. In PD fibroblasts, all treatments were effective in reducing H₂O₂ levels, while patients’ ATP content was modulated differently, probably due to the varying mutations in the PARK2 gene found in individual patients which are also involved in different mitochondrial phenotypes. We also investigated the effect of sumac extract on THP-1-differentiated macrophages, which show different embryogenic origin with respect to fibroblasts. In THP-1 macrophages, sumac treatment determined a reduction in H₂O₂ levels and an increase in the mitochondrial ATP content in M1, assuming that sumac could polarize the M1 to M2 phenotype, as demonstrated with other food-derived compounds rich in polyphenols. In conclusion, Rhus coriaria L. extracts could represent a potential nutraceutical approach to PD.

Arginase: shedding light on the mechanisms and opportunities in cardiovascular diseases

Arginase, a binuclear manganese metalloenzyme in the urea, catalyzes the hydrolysis of L-arginine to urea and L-ornithine. Both isoforms, arginase 1 and arginase 2 perform significant roles in the regulation of cellular functions in cardiovascular system, such as senescence, apoptosis, proliferation, inflammation, and autophagy, via a variety of mechanisms, including regulating L-arginine metabolism and activating multiple signal pathways. Furthermore, abnormal arginase activity contributes to the initiation and progression of a variety of CVDs. Therefore, targeting arginase may be a novel and promising approach for CVDs treatment. In this review, we give a comprehensive overview of the physiological and biological roles of arginase in a variety of CVDs, revealing the underlying mechanisms of arginase mediating vascular and cardiac function, as well as shedding light on the novel and promising therapeutic approaches for CVDs therapy in individuals.

Modification of the chemically induced inflammation assay reveals the Janus face of a phenol rich fulvic acid

Inflammation is an essential process as a reaction towards infections or wounding. Exposure to hazardous environmental pollutants can lead to chronic inflammations, where the resolving phase is delayed or blocked. Very contradictory studies have been reported on the pro- and anti-inflammatory effects of humic substances (HSs) leading to significant disagreements between researchers. To a certain extent, this can be attributed to the chemical heterogeneity of this group of xenobiotics. Here we show for the first time that pro- and anti-inflammatory effects can occur by one HSs. We adapted an assay that uses green fluorescence-labeled zebrafish larvae and CuSO₄ to indue an inflammation. In wild-type larvae, exposure to 50 µM CuSO₄ for 2 h activated the production of reactive oxygen species, which can be monitored with a fluorescence dye (H2DCFDA) and a microplate reader. This allows not only the use of wild-type fish but also a temporal separation of copper exposure and inflammatory substance while retaining the high throughput. This modified assay was then used to evaluate the inflammatory properties of a fulvic acid (FA). We found, that the aromatic structure of the FA protects from inflammation at 5 and 50 mg C/L, while the persistent free radicals enhance the copper-induced inflammation at ≥ 300 mg C/L.

Characterization of the foreign body response of titanium implants modified with polyphenolic coatings

The foreign body response is dictating the outcome of wound healing around any implanted materials. Patients who suffer from chronic inflammatory diseases and impaired wound healing often face a higher risk for implant failure. Therefore, functional surfaces need to be developed to improve tissue integration. For this purpose, we evaluated the impact of surface coatings made of antioxidant polyphenolic molecules tannic acid (TA) and pyrogallol (PG) on the host response in human blood. Our results showed that although the polyphenolic surface modifications impact the initial blood protein adsorption compared to Ti, the complement and coagulation systems are triggered. Despite complement activation, monocytes and granulocytes remained inactivated, which was manifested in a low pro-inflammatory cytokine expression. Under oxidative stress, both coatings were able to reduce intracellular reactive oxygen species in human gingival fibroblasts (hGFs). However, no anti-inflammatory effects of polyphenolic coatings could be verified in hGFs stimulated with lipopolysaccharide and IL-1β. Although polyphenols reportedly inhibit the NF-κB signaling pathway, phosphorylation of NF-κB p65 was observed. In conclusion, our results indicated that TA and PG coatings improved the hemocompatibility of titanium surfaces and have the potential to reduce oxidative stress during wound healing.

Polyphenols as the Potential Disease-modifying Therapy in Cancer

BACKGROUND

Disease-modifying therapy in cancer can be defined as long-term treatment that has a beneficial outcome on the course of cancer, affecting the underlying pathophysiology. The anticancer potential of polyphenols is widely studied. However, there is a significant gap between experimental data obtained in vitro and in vivo and the current polyphenol role in cancer therapy.

OBJECTIVE

In this article, the reason for this inconsistency is discussed, which might be in the design of polyphenols clinical trials. The approach of long-term polyphenol disease-modifying therapy in cancer is encouraged.

CONCLUSION

As the physiologic concentrations of polyphenols are not sufficient for reaching the cytotoxic levels, the immune-modulatory effects and effects on cancer intrinsic signal transduction pathways should be considered in polyphenol clinical trials design. Such effects apparently can not cause the rapid regression of the disease. However, more likely, they can modulate the course of the disease, leading to favorable changes in the patient's condition in case of long-term treatment that can be considered to be cancer disease modification.

Inflammation Markers in Adipose Tissue and Cardiovascular Risk Reduction by Pomegranate Juice in Obesity Induced by a Hypercaloric Diet in Wistar Rats

Pomegranate juice (Punica granatum) has been used since ancient times in traditional medicine (Unani Medicine, Ayurveda); its main compounds are anthocyanins and ellagic acid, which have anti-inflammatory, antioxidant, hepatoprotective, and cardiovascular health effects. The objective was to evaluate the effect of pomegranate juice on inflammation, blood pressure, and vascular and physiological markers associated with obesity induced by a high-fat diet in a murine model. The results show that pomegranate juice reduces the concentration of low-density lipoprotein cholesterol (cLDL) 39% and increases the concentration of high-density lipoprotein cholesterol (cHDL) by 27%, leading to a 12%-18% decrease in the risk of cardiovascular diseases (CVD). In addition to reducing blood pressure by 24%, it also had an antiatherogenic effect by decreasing sE-selectin levels by 42%. On the other hand, the juice significantly increased adiponectin levels in adipose tissue, decreased levels of inflammation markers (tumor necrosis factor-α (TNF-α), plasminogen activator inhibitor-1 (PAI-1), interleukin-17A (IL-17A), interleukin-6 (IL-6), interleukin-1β (IL-1β)), and inhibited the monocyte chemoattractant protein-1 (MCP-1). Pomegranate juice requires clinical studies to prove its immunoregulatory and therapeutic effects on cardiovascular and atherogenic risks.

Punicalagin Attenuates Disturbed Flow-Induced Vascular Dysfunction by Inhibiting Force-Specific Activation of Smad1/5

Background

Pathophysiological vascular remodeling in response to disturbed flow with low and oscillatory shear stress (OSS) plays important roles in atherosclerosis progression. Pomegranate extraction (PE) was reported having anti-atherogenic effects. However, whether it can exert a beneficial effect against disturbed flow-induced pathophysiological vascular remodeling to inhibit atherosclerosis remains unclear. The present study aims at investigating the anti-atherogenic effects of pomegranate peel polyphenols (PPP) extraction and its purified compound punicalagin (PU), as well as their protective effects on disturbed flow-induced vascular dysfunction and their underlying molecular mechanisms.

Methods

The anti-atherogenic effects of PPP/PU were examined on low-density lipoprotein receptor knockout mice fed with a high fat diet. The vaso-protective effects of PPP/PU were examined in rat aortas using myograph assay. A combination of in vivo experiments on rats and in vitro flow system with human endothelial cells (ECs) was used to investigate the pharmacological actions of PPP/PU on EC dysfunction induced by disturbed flow. In addition, the effects of PPP/PU on vascular smooth muscle cell (VSMC) dysfunction were also examined.

Results

PU is the effective component in PPP against atherosclerosis. PPP/PU evoked endothelium-dependent relaxation in rat aortas. PPP/PU inhibited the activation of Smad1/5 in the EC layers at post-stenotic regions of rat aortas exposed to disturbed flow with OSS. PPP/PU suppressed OSS-induced expression of cell cycle regulatory and pro-inflammatory genes in ECs. Moreover, PPP/PU inhibited inflammation-induced VSMC dysfunction.

Conclusion

PPP/PU protect against OSS-induced vascular remodeling through inhibiting force-specific activation of Smad1/5 in ECs and this mechanism contributes to their anti-atherogenic effects.

Reducing NF-κB Signaling Nutritionally is Associated with Expedited Recovery of Skeletal Muscle Function After Damage

CONTEXT

The early events regulating the remodeling program following skeletal muscle damage are poorly understood.

OBJECTIVE

The objective of this study was to determine the association between myofibrillar protein synthesis (myoPS) and nuclear factor-kappa B (NF-κB) signaling by nutritionally accelerating the recovery of muscle function following damage.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS

Healthy males and females consumed daily postexercise and prebed protein-polyphenol (PP; n = 9; 4 females) or isocaloric maltodextrin placebo (PLA; n = 9; 3 females) drinks (parallel design) 6 days before and 3 days after 300 unilateral eccentric contractions of the quadriceps during complete dietary control.

MAIN OUTCOME MEASURES

Muscle function was assessed daily, and skeletal muscle biopsies were taken after 24, 27, and 36 hours for measurements of myoPS rates using deuterated water, and gene ontology and NF-κB signaling analysis using a quantitative reverse transcription PCR (RT-qPCR) gene array.

RESULTS

Eccentric contractions impaired muscle function for 48 hours in PLA intervention, but just for 24 hours in PP intervention (P = 0.047). Eccentric quadricep contractions increased myoPS compared with the control leg during postexercise (24-27 hours; 0.14 ± 0.01 vs 0.11 ± 0.01%·h-1, respectively; P = 0.075) and overnight periods (27-36 hours; 0.10 ± 0.01 vs 0.07 ± 0.01%·h-1, respectively; P = 0.020), but was not further increased by PP drinks (P > 0.05). Protein-polyphenol drinks decreased postexercise and overnight muscle IL1R1 (PLA = 2.8 ± 0.4, PP = 1.1 ± 0.4 and PLA = 1.9 ± 0.4, PP = 0.3 ± 0.4 log2 fold-change, respectively) and IL1RL1 (PLA = 4.9 ± 0.7, PP = 1.6 ± 0.8 and PLA = 3.7 ± 0.6, PP = 0.7 ± 0.7 log2 fold-change, respectively) messenger RNA expression (P < 0.05) and downstream NF-κB signaling compared with PLA.

CONCLUSION

Protein-polyphenol drink ingestion likely accelerates recovery of muscle function by attenuating inflammatory NF-κB transcriptional signaling, possibly to reduce aberrant tissue degradation rather than increase myoPS rates.

Punicalagin ameliorates collagen-induced arthritis by downregulating M1 macrophage and pyroptosis via NF-κB signaling pathway

Rheumatoid arthritis (RA) is a chronic inflammatory disease that eventually leads to disability. Inflammatory cell infiltration, severe joint breaking and systemic bone loss are the main clinical symptoms. In this study, we established a collagen-induced arthritis (CIA) model and found a large number of M1 macrophages and pyroptosis, which are important sources of proinflammatory cytokines. Punicalagin (PUN) is an active substance extracted from pomegranate peel. We found that it inhibited joint inflammation, cartilage damage and systemic bone destruction in CIA mice. PUN effectively alleviated the high expression of inflammatory cytokines in synovial tissue in vivo. PUN treatment shifted macrophages from the M1 phenotype to the M2 phenotype after stimulation with lipopolysaccharide (LPS) and interferon (IFN)-γ. The expression of inducible nitric oxide synthase (iNOS) and other proinflammatory cytokines released by M1 macrophages was decreased in the PUN treatment group. However, simultaneously, the expression of markers of anti-inflammatory M2 macrophages, such as arginase (Arg)-1 and interleukin (IL)-10, was increased. In addition, PUN treatment attenuated pyroptosis by downregulating the expression of NLRP3 and caspase-1, thereby preventing inflammatory cell death resulting from the release of IL-1β and IL-18. Mechanistically, PUN inhibited the activation of receptor activators of the nuclear factor-κB (NF-κB) signaling pathway, which contributes to M1 polarization and pyroptosis of macrophages. We concluded that PUN ameliorated pathological inflammation by inhibiting M1 phenotype polarization and pyroptosis and has great potential as a therapeutic treatment for human RA.

Macrophage Plasticity and Atherosclerosis Therapy

Atherosclerosis is a chronic disease starting with the entry of monocytes into the subendothelium and the subsequent differentiation into macrophages. Macrophages are the major immune cells in atherosclerotic plaques and are involved in the dynamic progression of atherosclerotic plaques. The biological properties of atherosclerotic plaque macrophages determine lesion size, composition, and stability. The heterogenicity and plasticity of atherosclerotic macrophages have been a hotspot in recent years. Studies demonstrated that lipids, cytokines, chemokines, and other molecules in the atherosclerotic plaque microenvironment regulate macrophage phenotype, contributing to the switch of macrophages toward a pro- or anti-atherosclerosis state. Of note, M1/M2 classification is oversimplified and only represent two extreme states of macrophages. Moreover, M2 macrophages in atherosclerosis are not always protective. Understanding the phenotypic diversity and functions of macrophages can disclose their roles in atherosclerotic plaques. Given that lipid-lowering therapy cannot completely retard the progression of atherosclerosis, macrophages with high heterogeneity and plasticity raise the hope for atherosclerosis regression. This review will focus on the macrophage phenotypic diversity, its role in the progression of the dynamic atherosclerotic plaque, and finally discuss the possibility of treating atherosclerosis by targeting macrophage microenvironment.

Functionalization with a Polyphenol-Rich Pomace Extract Empowers a Ceramic Bone Filler with In Vitro Antioxidant, Anti-Inflammatory, and Pro-Osteogenic Properties

Oral diseases and periodontitis in particular are a major health burden worldwide, because of their association with various systemic diseases and with conditions such as peri-implantitis. Attempts have been made over the years to reverse bone loss due to the host disproportionate inflammatory response and to prevent failure of dental implants. To this end, the use of biomaterials functionalized with molecules characterized by anti-inflammatory and antioxidant properties could represent a new frontier for regenerating functional periodontal tissues. In this study, a new ceramic granulated biomaterial, named Synergoss Red (SR), functionalized with a polyphenolic mixture extracted from pomace of the Croatina grape variety, is introduced. Following a preliminary in-depth characterization of the extract by HPLC analysis and of the biomaterial surface and composition, we performed evaluations of cytocompatibility and a biological response through in vitro assays. The anti-inflammatory and antioxidant properties of the identified phenolic molecules contained in SR were shown to downregulate inflammation in macrophages, to stimulate in osteoblast-like cells the expression of genes involved in deposition of the early bone matrix, and to mitigate bone remodeling by decreasing the RANKL/OPG ratio. Thanks to its cytocompatibility and assorted beneficial effects on bone regeneration, SR could be considered an innovative regenerative approach in periodontal therapy.

The Role of Mitochondria in Immune-Cell-Mediated Tissue Regeneration and Ageing

During tissue injury events, the innate immune system responds immediately to alarms sent from the injured cells, and the adaptive immune system subsequently joins in the inflammatory reaction. The control mechanism of each immune reaction relies on the orchestration of different types of T cells and the activators, antigen-presenting cells, co-stimulatory molecules, and cytokines. Mitochondria are an intracellular signaling organelle and energy plant, which supply the energy requirement of the immune system and maintain the system activation with the production of reactive oxygen species (ROS). Extracellular mitochondria can elicit regenerative effects or serve as an activator of the immune cells to eliminate the damaged cells. Recent clarification of the cytosolic escape of mitochondrial DNA triggering innate immunity underscores the pivotal role of mitochondria in inflammation-related diseases. Human mesenchymal stem cells could transfer mitochondria through nanotubular structures to defective mitochondrial DNA cells. In recent years, mitochondrial therapy has shown promise in treating heart ischemic events, Parkinson's disease, and fulminating hepatitis. Taken together, these results emphasize the emerging role of mitochondria in immune-cell-mediated tissue regeneration and ageing.

Nrf2 a molecular therapeutic target for Astaxanthin

Astaxanthin (ATX) is a red pigment carotenoid present in shrimp, salmon, crab, and asteroidean. Several studies have corroborated the anti-oxidant efficacy of ATX. In addition, ATX has anti-inflammatory, anti-apoptotic and anti-proliferative properties. In the present review, we discuss the role of Nrf2 in mediating the anti-cancer, anti-aging, neuroprotective, lung-protective, skin-protective, cardioprotective, hepatoprotective, anti-diabetic and muscloprotective effects of ATX.

The Paired Siglecs in Brain Tumours Therapy: The Immunomodulatory Effect of Dexamethasone and Temozolomide in Human Glioma In Vitro Model

The paired sialic acid-binding immunoglobulin like lectins (Siglecs) are characterized by similar cellular distribution and ligand recognition but opposing signalling functions attributed to different intracellular sequences. Since sialic acid—Siglec axis are known to control immune homeostasis, the imbalance between activatory and inhibitory mechanisms of glycan-dependent immune control is considered to promote pathology. The role of sialylation in cancer is described, however, its importance in immune regulation in gliomas is not fully understood. The experimental and clinical observation suggest that dexamethasone (Dex) and temozolomide (TMZ), used in the glioma management, alter the immunity within the tumour microenvironment. Using glioma-microglia/monocytes transwell co-cultures, we investigated modulatory action of Dex/TMZ on paired Siglecs. Based on real-time PCR and flow cytometry, we found changes in SIGLEC genes and their products. These effects were accompanied by altered cytokine profile and immune cells phenotype switching measured by arginases expression. Additionally, the exposure to Dex or TMZ increased the binding of inhibitory Siglec-5 and Siglec-11 fusion proteins to glioma cells. Our study suggests that the therapy-induced modulation of the interplay between sialoglycans and paired Siglecs, dependently on patient’s phenotype, is of particular signification in the immune surveillance in the glioma management and may be useful in glioma patient’s therapy plan verification.

Pomegranate variety and pomegranate plant part, relevance from bioactive point of view: a review

Pomegranate (Punica granatum L.) belongs to the Punicaceae plant family. It is an important fruit due to its nutritional and medicinal properties. Pomegranates are widely distributed around the world and, therefore, have a broad genetic diversity, resulting in differences in their phytochemical composition. The scientific community has focused on the positive health effects of pomegranate as a whole, but the different varieties have rarely been compared according to their bioactive compounds and bioactivity. This review aims to provide a holistic overview of the current knowledge on the bioactivity of pomegranate trees, with an emphasis on differentiating both the varieties and the different plant parts. This review intends to provide a general and organized overview of the accumulated knowledge on pomegranates, the identification of the most bioactive varieties, their potential consumption pathways and seeks to provide knowledge on the present gaps to guide future research.

Acorn flour properties depending on the production method and laboratory baking test results: A review

Acorns, the fruit of the oak, have long been an important source of food in different cultures around the world. Despite their long culinary tradition, they have become under-appreciated. Due to their high starch content, acorns are mainly used for flour production, and acorn flour is considered as a replacement for cereal flour in a wide range of applications in food production. This study reviewed the published literature concerning acorn flour production and composition as well as the possibility of using acorn flour in the most popular flour-based products such as bread, cake, and cookies. The study also presents the advantages resulting from acorn flour incorporation to the human diet and acorn flour influence on the quality of bread and pastry products. This review found that acorn flour is characterized by a lack of gluten proteins and a high content of fiber and minerals as well as the presence of polyphenols with antioxidant properties. However, negative impact of its larger amount on the dough rheological features and product physical properties has been emphasized in many studies. The researchers recommend the incorporation of acorn flour up to a level of 15% in formulating composite flour for bread production. However, the literature data indicates that acorn flour substitution for pastry production depends on the product type and ranges from 10 to even 60%. It is also highlighted that the application of acorn flour into gluten-free products is particularly favorable from a nutritional point of view.

Urolithin A attenuated ox-LDL-induced cholesterol accumulation in macrophages partly through regulating miR-33a and ERK/AMPK/SREBP1 signaling pathways

Promoting cholesterol efflux from foam cells represents one of the therapeutic strategies for ameliorating atherosclerosis. Urolithin A (UA) has been shown before to attenuate ox-LDL induced endothelial dysfunction in endothelial cells with its anti-inflammatory properties. The aim of this study was to investigate whether UA could promote cholesterol efflux via modulating related microRNA (miR) and signaling pathways. RAW264.7 cells were treated with 50 μg mL^-1 ox-LDL to induce foam cell formation. After treatment with UA at different concentrations, intercellular and extracellular cholesterol levels were determined. Expression of Erk1/2, AMPKα and their phosphorylation forms, and SREBP1, was analyzed by western-blotting. The effect of UA on miR-33a expression and the involvement of miR-33a in cholesterol efflux regulation were also investigated. UA reduced ox-LDL induced cholesterol accumulation in macrophage cells and promoted cholesterol efflux from cells. Compared with ox-LDL treated cells, UA treatment reduced the level of phosphorylated ERK1/2, increased the expression of phosphorylated AMPKα and decreased the SREBP1 expression. Moreover, UA decreased the miR-33a expression at the transcriptional level but increased the transcriptional expression of ATP-binding cassette transporter A1 (ABCA1) and ABCG1, two genes contributing to reverse cholesterol transport. Furthermore, pre-miR-33a attenuated cholesterol efflux induced by UA. Collectively, UA promoted the reverse cholesterol transport in macrophage-derived foam cells and interfered with cholesterol metabolism possibly through regulating the miRNA-33 expression and interaction with the ERK/AMPKα/SREBP1 signaling pathway.

Impact of polyphenols in phagocyte functions

Polyphenols are a broad group of substances with potential health benefits found in plant species. Several of these compounds are capable of influencing the activation of intracellular signaling pathways, such as NF-kB, MAPK and JAK-STAT, responsible for the production of various inflammatory mediators such as tumor necrosis factor α (TNF-α) and interleukin 1 beta (IL-1β) and 12 (IL-12), enzymes involved in the production of reactive species such as inducible nitric oxide synthase (iNOS) and superoxide dehydrogenase (SOD), as well as enzymes involved in the production of eicosanoids, such as cyclooxygenase (COX) and lipoxygenase (LO). There is increased interest in the use of polyphenol-rich foods because of their immunomodulatory effect; however, the mechanisms used during macrophage responses are extremely complex and little is known about the effects of polyphenols on these cells. As such, this review summarizes the current view of polyphenol influences on macrophages.

Purple corn extract induces long-lasting reprogramming and M2 phenotypic switch of adipose tissue macrophages in obese mice

Background

Obesity is a chronic and systemic inflammatory disorder and an important risk factor for the onset of several chronic syndromes. Adipose tissue (AT) plays a crucial role in the development of obesity, promoting the infiltration and accumulation of leukocytes in the tissue and sustaining adipocyte expansion. Anthocyanins exert a broad range of health benefits, but their effect in improving obesity-related inflammation in vivo has been poorly characterized. We examined the effects of a purple corn cob extract in the context of AT inflammation in a murine diet-induced obesity (DIO) model.

Methods

Male C57BL/6J mice were subjected to control diet (CTR + H₂O), high fat diet (HF + H₂O) or high fat diet plus purple corn extract (HF + RED) for 12 weeks. Blood glucose, AT, and liver gene expression, metabolism, biochemistry, and histology were analysed and flow cytometry was performed on AT leukocytes and Kupffer cells.

Results

RED extract intake resulted in lower MCP-1 mediated recruitment and proliferation of macrophages into crown-like structures in the AT. AT macrophages (ATM) of HF + RED group upregulated M2 markers (ArgI, Fizz1, TGFβ), downregulating inflammatory mediators (TNF-α, IL-6, IL-1β, COX-2) thanks to the suppression of NF-kB signalling. ATM also increased the expression of iron metabolism-related genes (FABP4, Hmox1, Ferroportin, CD163, TfR1, Ceruloplasmin, FtL1, FtH1) associated with a reduction in iron storage and increased turnover. ATM from HF + RED mice did not respond to LPS treatment ex vivo, confirming the long-lasting effects of the treatment on M2 polarization. Adipocytes of HF + RED group improved lipid metabolism and displayed a lower inflammation grade. Liver histology revealed a remarkable reduction of steatosis in the HF + RED group, and Kupffer cell profiling displayed a marked switch towards the M2 phenotype.

Conclusions

RED extract attenuated AT inflammation in vivo, with a long-lasting reprogramming of ATM and adipocyte profiles towards the anti-inflammatory phenotype, therefore representing a valuable supplement in the context of obesity-associated disorders.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1972-6) contains supplementary material, which is available to authorized users.

The Role of Metabolic Remodeling in Macrophage Polarization and Its Effect on Skeletal Muscle Regeneration

Significance: Macrophages are crucial for tissue homeostasis. Based on their activation, they might display classical/M1 or alternative/M2 phenotypes. M1 macrophages produce pro-inflammatory cytokines, reactive oxygen species (ROS), and nitric oxide (NO). M2 macrophages upregulate arginase-1 and reduce NO and ROS levels; they also release anti-inflammatory cytokines, growth factors, and polyamines, thus promoting angiogenesis and tissue healing. Moreover, M1 and M2 display key metabolic differences; M1 polarization is characterized by an enhancement in glycolysis and in the pentose phosphate pathway (PPP) along with a decreased oxidative phosphorylation (OxPhos), whereas M2 are characterized by an efficient OxPhos and reduced PPP. Recent Advances: The glutamine-related metabolism has been discovered as crucial for M2 polarization. Vice versa, flux discontinuities in the Krebs cycle are considered additional M1 features; they lead to increased levels of immunoresponsive gene 1 and itaconic acid, to isocitrate dehydrogenase 1-downregulation and to succinate, citrate, and isocitrate over-expression. Critical Issues: A macrophage classification problem, particularly in vivo, originating from a gap in the knowledge of the several intermediate polarization statuses between the M1 and M2 extremes, characterizes this field. Moreover, the detailed features of metabolic reprogramming crucial for macrophage polarization are largely unknown; in particular, the role of β-oxidation is highly controversial. Future Directions: Manipulating the metabolism to redirect macrophage polarization might be useful in various pathologies, including an efficient skeletal muscle regeneration. Unraveling the complexity pertaining to metabolic signatures that are specific for the different macrophage subsets is crucial for identifying new compounds that are able to trigger macrophage polarization and that might be used for therapeutical purposes.

M2 Macrophages as a Potential Target for Antiatherosclerosis Treatment

Atherosclerosis is a chronic progressive inflammation course, which could induce life-threatening diseases such as stroke and myocardial infarction. Optimal medical treatments for atherosclerotic risk factors with current antihypertensive and lipid-lowering drugs (for example, statins) are widely used in clinical practice. However, many patients with established disease still continue to have recurrent cardiovascular events in spite of treatment with a state-of-the-art therapy. Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of mortality worldwide. Hence, current treatment of atherosclerosis is still far from being satisfactory. Recently, M2 macrophages have been found associated with atherosclerosis regression. The M2 phenotype can secrete anti-inflammatory factors such as IL-10 and TGF-β, promote tissue remodeling and repairing through collagen formation, and clear dying cells and debris by efferocytosis. Therefore, modulators targeting macrophages' polarization to the M2 phenotype could be another promising treatment strategy for atherosclerosis. Two main signaling pathways, the Akt/mTORC/LXR pathway and the JAK/STAT6 pathway, are found playing important roles in M2 polarization. In addition, researchers have reported several potential approaches to modulate M2 polarization. Inhibiting or activating some kinds of enzymes, affecting transcription factors, or acting on several membrane receptors could regulate the polarization of the M2 phenotype. Besides, biomolecules, for example vitamin D, were found to affect the process of M2 polarization. Pomegranate juice could promote M2 polarization via unclear mechanism. In this review, we will discuss how M2 macrophages affect atherosclerosis regression, signal transduction in M2 polarization, and outline potential targets and compounds that affect M2 polarization, thus controlling the progress of atherosclerosis.

Plasticity of antimicrobial and phagocytic programs in human macrophages

Macrophage (MΦ) polarization is triggered during the innate immune response to defend against microbial pathogens, but can also contribute to disease pathogenesis. In a previous study, we found that interleukin-15 (IL-15) -derived classically activated macrophages (M1 MΦ) have enhanced antimicrobial activity, whereas IL-10-derived alternatively activated macrophages (M2 MΦ) were highly phagocytic but lacked antimicrobial activity. Given that the ability to modulate MΦ polarization from M2 MΦ to M1 MΦ may promote a more effective immune response to infection, we investigated the plasticity of these MΦ programs. Addition of IL-10 to M1 MΦ induced M2-like MΦ, but IL-15 had little effect on M2 MΦ. We determined the set of immune receptors that are present on M2 MΦ, elucidating two candidates for inducing plasticity of M2 MΦ, Toll-like receptor 1 (TLR1) and interferonγ (IFN-γ) receptor 1. Stimulation of M2 MΦ with TLR2/1 ligand (TLR2/1L) or IFN-γ alone was not sufficient to alter M2 MΦ phenotype or function. However, co-addition of TLR2/1L and IFN-γ re-educated M2 MΦ towards the M1 MΦ phenotype, with a decrease in the phagocytosis of lipids and mycobacteria, as well as recovery of the vitamin-D-dependent antimicrobial pathway compared with M2 MΦ maintained in polarizing conditions. Similarly, treatment of M2 MΦ with both TLR2/1L and anti-IL-10 neutralizing antibodies led to polarization to the M1-like MΦ phenotype and function. Together, our data demonstrate an approach to induce MΦ plasticity that provides the potential for re-educating MΦ function in human mycobacterial disease to promote host defense and limit pathogenesis.

Attenuation of Atherosclerosis by Protocatechuic Acid via Inhibition of M1 and Promotion of M2 Macrophage Polarization

Macrophage polarization has a vital impact on the progression of atherosclerosis (AS). Protocatechuic acid (PCA), a flavonol, displays notable atheroprotective effects, but its mechanisms have not been clearly defined. We investigated whether PCA attenuated AS by regulating macrophage polarization. PCA consumption inhibited HCD-induced plaque formation (17.84 and 8.21% in the HCD and HCD with PCA groups, respectively, p < 0.05) and inflammatory responses in apolipoprotein E deficient (ApoE^-/-) mice. Moreover, PCA suppressed classically activated macrophage (M1) polarization, which decreased the secretion of nitric oxide synthase (54.63 and 32.86% in the HCD and HCD with PCA groups, respectively, p < 0.05) and proinflammatory factors. PCA promoted alternatively activated macrophage (M2) activation, which increased the expression of arginine I (6.97 and 26.19% in the HCD and HCD with PCA groups, respectively, p < 0.001) and anti-inflammatory factors. PCA also regulated M1-M2 polarization in J774 cells and mouse-bone-marrow-derived macrophages. Finally, PCA reduced PI3K-Akt-mediated nuclear-factor-κB activation, thereby suppressing M1 polarization, and provoked signal-transducers-and-activators-of-transcription-6 phosphorylation and peroxisome-proliferator-activated-receptor-γ activation, leading to enhanced M2 activation. Our data revealed that PCA alleviated AS by regulating M1-M2 conversion.

Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention

Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.

Unsaturated Fatty Acids Improve Atherosclerosis Markers in Obese and Overweight Non-diabetic Elderly Patients

BACKGROUND

Several studies have demonstrated the benefits of replacing trans and saturated fats with unsaturated fatty acids on cardiovascular diseases. We aimed to demonstrate the effect of polyunsaturated and monounsaturated fat supplementation on the biochemical and endothelial markers of atherosclerotic disease in obese or overweight non-diabetic elderly patients.

METHOD

Seventy-nine patients were randomly divided into three groups: flaxseed oil, olive oil, and sunflower oil; patients in each group received 30 mL of oil for 90 days. Patients were subjected to anthropometric and bioimpedance assessments; biochemical and endothelial evaluations were performed through ultrasonography of the brachial artery and carotid artery for endothelium-dependent dilation and intima-media thickness assessment, respectively, before and after the intervention. The participants' usual diet remained unchanged.

RESULTS

The flaxseed oil group had improved ultra-sensitive C-reactive protein levels (p = 0.074) and reduced carotid intima-media thickness (CIMT) (p = 0.028); the olive oil group exhibited an improved apolipoprotein (Apo)B/ApoA ratio (p = 0.021), reduced CIMT (p = 0.028), and improved flow-mediated vasodilation (FMV) (p = 0.054); and similarly, the sunflower oil group showed an improved ApoB/ApoA ratio (p = 0.024), reduced CIMT (p = 0.048), and improved FMV (p = 0.001).

CONCLUSION

Unsaturated fatty acid supplementation using the three vegetable oils attenuated pro-inflammatory properties and improved prothrombotic conditions. Therefore, introducing or replacing saturated and trans fat with unsaturated fatty acids is beneficial for cardiovascular risk reduction in obese or overweight non-diabetic elderly people. Further studies are needed to determine which unsaturated fat best prevents cardiovascular disease in elderly patients.

Effect of pomegranate juice consumption on biochemical parameters and complete blood count

Pomegranate has been used therapeutically for centuries. The aim of the present study was to examine the effects of pomegranate juice (PJ) supplementation on complete blood count (CBC), glucose, blood lipids and C-reactive protein (CRP) in healthy subjects. A total of 5 males and 5 females (aged 31.8±6.6 years, weighing 66.2±12.9 kg) were randomly assigned into one of two groups and either consumed 500 ml PJ/day or no PJ for 14 days. Blood samples were obtained from participants prior to and following the experimental period. PJ consumption resulted in a significant increase in red blood cell count (P<0.05), hemoglobin levels (P<0.001) and hematocrit levels (P<0.05). Other CBC parameters, glucose, cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein and CRP levels did not significantly change following PJ consumption. These results indicate that PJ intake for a short period of time may result in increased erythropoiesis or decreased degradation without any significant alterations in factors associated with metabolic health and inflammation in healthy individuals.

Punicalagin, a polyphenol from pomegranate fruit, induces growth inhibition and apoptosis in human PC-3 and LNCaP cells

Prostate cancer (PCa) is an international health problem and search for its effective treatment is in progress. Punicalagin (PN), polyphenol from pomegranate fruit, is known to exhibit potent anticancer activity in lung, breast and cervical cells. However, there is paucity of information on its effect in PCa. This study evaluated anti-proliferative effects of PN and its effects on extrinsic pathway of apoptosis in PCa cells, and angiogenesis in chicken chorioallantoic membrane (CAM). Antioxidant activities of PN were determined by 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging and inhibition of lipid peroxidation (LPO) methods. PCa (PC-3 and LNCaP) and normal prostate (BPH-1) cells were cultured and treated with PN (10, 50 and 100 μM). Cytotoxicity and viability effects of PN were determined by lactate dehydrogenase (LDH) and XTT assays, respectively. Antiangiogenic effects were measured using CAM assay, while apoptosis was assessed by DNA fragmentation, enrichment factor by Cell Death Detection ELISA kit and expressions of caspases-3 and -8. Results showed that PN (10-200 μM) significantly scavenged DPPH and inhibited LPO in a concentration-dependent manner. Furthermore, PN (10-100 μM) concentration-dependently inhibited viability in PC-3 and LNCaP, while viability in BPH-1 was insignificantly affected. PN had low toxicity on cells in vitro at concentrations tested. Also, PN (100 μM) increased enrichment factor in PC-3 (2.34 ± 0.05) and LNCaP (2.31 ± 0.26) relative to control (1.00 ± 0.00). In addition, PN (50 μM) decreased the network of vessels in CAM, suggesting its anti-angiogenic effect. Moreso, PN increased the expressions of caspases-3 and -8 in PC-3. Overall, PN exerts anti-proliferative activity in PCa cells via induction of apoptosis and anti-angiogenic effect.

Effect of Cocoa Polyphenolic Extract on Macrophage Polarization from Proinflammatory M1 to Anti-Inflammatory M2 State

Polyphenols-rich cocoa has many beneficial effects on human health, such as anti-inflammatory effects. Macrophages function as control switches of the immune system, maintaining the balance between pro- and anti-inflammatory activities. We investigated the hypothesis that cocoa polyphenol extract may affect macrophage proinflammatory phenotype M1 by favoring an alternative M2 anti-inflammatory state on macrophages deriving from THP-1 cells. Chemical composition, total phenolic content, and antioxidant capacity of cocoa polyphenols extracted from roasted cocoa beans were determined. THP-1 cells were activated with both lipopolysaccharides and interferon-γ for M1 or with IL-4 for M2 switch, and specific cytokines were quantified. Cellular metabolism, through mitochondrial oxygen consumption, and ATP levels were evaluated. Here, we will show that cocoa polyphenolic extract attenuated in vitro inflammation decreasing M1 macrophage response as demonstrated by a significantly lowered secretion of proinflammatory cytokines. Moreover, treatment of M1 macrophages with cocoa polyphenols influences macrophage metabolism by promoting oxidative pathways, thus leading to a significant increase in O₂ consumption by mitochondrial complexes as well as a higher production of ATP through oxidative phosphorylation. In conclusion, cocoa polyphenolic extract suppresses inflammation mediated by M1 phenotype and influences macrophage metabolism by promoting oxidative pathways and M2 polarization of active macrophages.

Peroxisome proliferator-activated receptor-γ-mediated polarization of macrophages in Neospora caninum infection

BACKGROUND

Neospora caninum is an apicomplexan parasite closely related Toxoplasma gondii, which causes neurological disease and abortion in multiple animal species. Macrophage polarization plays an important role in host immune responses to parasites infection, such as Toxoplasma gondii, Leishmania, Trypanosoma cruzi. However, the dynamics of macrophage polarization, as well as the possible mechanism that regulate macrophage polarization, during N. caninum infection remains unclear.

METHODS

The M1 and M2-phenotypic markers of peritoneal macrophages from mice infected with tachyzoites of Nc-1 were analyzed by flow cytometry (FCM) analysis. Then J774A.1 cells were respectively treated with GW9662 and RGZ, and stimulated by tachyzoites of Nc-1. M1 and M2-phenotypic markers were determined by FCM and ELISA. And the activations of PPAR-γ and NF-κB were determined by Western blotting.

RESULTS

In this study, our data showed that macrophages were preferentially differentiated into the M1 type during the acute stage of N. caninum infection, while the level of M2 macrophages significantly increased during the chronic stage of infection. In vitro study, compared with the GW9662 group and RGZ group, N. caninum can promote M2-polarized phenotype through up-regulate the activity of PPAR-γ and inhibting NF-κB activation.

CONCLUSION

In conclusion, this study demonstrated that macrophages are plastic since M1 differentiated macrophages can express M2 markers with N. caninum infection through up-regulating the activity of PPAR-γ and inhibting NF-κB activation and may be providing new insights for the prevention and treatment of N. caninum infection.

Immune Profile of Obese People and In Vitro Effects of Red Grape Polyphenols on Peripheral Blood Mononuclear Cells

The in vitro ability of polyphenols, extracted from red grape, to modulate peripheral blood mononuclear cell responses has been evaluated in 20 obese (Ob) people. With regard to cytokine release in response to phorbol myristate acetate (PMA), levels of interleukin-2 (IL-2), interferon-γ (IFN-γ), IL-4, IL-10, and IL-17 were higher in the Ob than in healthy (H) subjects. Vice versa, IL-21 concentrations were detected only in H people but they were undetectable in the Ob counterpart. In general terms, levels of IL-1β, IL-6, IL-8, and tumor necrosis factor-α were higher in Ob people when compared to H controls. On the other hand, polyphenols did not modify IFN-γ, IL-4, and IL-17 levels. However, an increase in IL-2 was observed in H individuals, whereas its levels were decreased in the Ob counterpart. Polyphenols significantly increased IL-10 release from H donors, whereas a trend to increase was observed in Ob people. In addition, polyphenols were able to significantly increase levels of H IL-21, while this was not the case in Ob people. Since IL-21 is an inducer of Th17 cells, it is likely that polyphenols may suppress the sources of this cytokine via production of IL-10. Accordingly, polyphenols decreased IL-1β and IL-6 release in comparison to H controls.

Acrolein increases macrophage atherogenicity in association with gut microbiota remodeling in atherosclerotic mice: protective role for the polyphenol-rich pomegranate juice

The unsaturated aldehyde acrolein is pro-atherogenic, and the polyphenol-rich pomegranate juice (PJ), known for its anti-oxidative/anti-atherogenic properties, inhibits macrophage foam cell formation, the hallmark feature of early atherosclerosis. This study aimed to investigate two unexplored areas of acrolein atherogenicity: macrophage lipid metabolism and the gut microbiota composition. The protective effects of PJ against acrolein atherogenicity were also evaluated. Atherosclerotic apolipoprotein E-deficient (apoE^-/-) mice that were fed acrolein (3 mg/kg/day) for 1 month showed significant increases in serum and aortic cholesterol, triglycerides, and lipid peroxides. In peritoneal macrophages isolated from the mice and in J774A.1 cultured macrophages, acrolein exposure increased intracellular oxidative stress and stimulated cholesterol and triglyceride accumulation via enhanced rates of their biosynthesis and over-expression of key regulators of cellular lipid biosynthesis: sterol regulatory element-binding proteins (SREBPs), 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR), and diacylglycerol acyltransferase1 (DGAT1). Acrolein-fed mice demonstrated a major shift in the gut microbiota composition, including a significant phylum-level change in increased Firmicutes and decreased Bacteroidetes. At the family level, acrolein significantly increased the prevalence of Ruminococcaceae and Lachnospiraceae of which the Coprococcus genus was significantly and positively correlated with serum, aortic and macrophage lipid levels and peroxidation. The pro-atherogenic effects of acrolein on serum, aortas, macrophages, and the gut microbiota were substantially abolished by PJ. In conclusion, these findings provide novel mechanisms by which acrolein increases macrophage lipid accumulation and alters the gut microbiota composition in association with enhanced atherogenesis. Moreover, PJ was found as an effective strategy against acrolein atherogenicity.

Evaluation of in vitro anti-inflammatory effects of crude ginger and rosemary extracts obtained through supercritical CO2 extraction on macrophage and tumor cell line: the influence of vehicle type

BACKGROUND

Numerous plants from have been investigated due to their anti-inflammatory activity and, among then, extracts or components of ginger (Zingiber officinale Roscoe) and rosemary (Rosmarinus officinalis L.), sources of polyphenolic compounds. 6-gingerol from ginger rhizome and carnosic acid and carnosol from rosemary leaves present anti-tumor, anti-inflammatory and antioxidant activities. However, the evaluation of the mechanisms of action of these and other plant extracts is limited due to their high hydrophobicity. Dimethylsulfoxide (DMSO) is commonly used as a vehicle of liposoluble materials to mammalian cells in vitro, presenting enhanced cell penetration. Liposomes are also able to efficiently deliver agents to mammalian cells, being capable to incorporate in their structure not only hydrophobic molecules, but also hydrophilic and amphiphilic compounds. Another strategy is based on the use of Pluronic F-68, a biocompatible low-foaming, non-ionic surfactant, to disperse hydrophobic components. Here, these three delivery approaches were compared to analyze their influence on the in vitro anti-inflammatory effects of ginger and rosemary extracts, at different concentrations, on primary mammalian cells and on a tumor cell line.

METHODS

Ginger and rosemary extracts free of organic solvents were obtained by supercritical fluid extraction and dispersed in DMSO, Pluronic F-68 or liposomes, in variable concentrations. Cell viability, production of inflammatory mediators and nitric oxide (NO) release were measured in vitro on J774 cell line and murine macrophages primary culture stimulated with bacterial lipopolysaccharide and interferon-γ after being exposed or not to these extracts.

RESULTS

Ginger and rosemary extracts obtained by supercritical CO2 extraction inhibited the production of pro-inflammatory cytokines and the release of NO by peritoneal macrophages and J774 cells. The delivery vehicles influenced the anti-inflammatory effects. Comparatively, the ginger extract showed the highest anti-inflammatory activity on the tumor cell line. Controversially, rosemary extract dispersed on DMSO induced a more significant IL-1 and TNF-α reduction than ginger extract in primary macrophages.

CONCLUSIONS

Amongst the tested delivery vehicles, DMSO was the most suitable, presenting reduced cytotoxicity, followed by Pluronic F-68 and liposomes, provably due to differences in their form of absorption, distribution and cellular metabolism. Co-administration of liposomes and plant extracts may cause death of macrophages cells and induction of NO production. It can be concluded that some of the beneficial effects attributed to extracts of ginger and rosemary may be associated with the inhibition of inflammatory mediators due to their high antioxidant activity. However, these effects were influenced by the type of delivery vehicle.

Paraoxonase 2 Induces a Phenotypic Switch in Macrophage Polarization Favoring an M2 Anti-Inflammatory State

Inflammatory processes are involved in atherosclerosis development. Macrophages play a major role in the early atherogenesis, and they are present in the atherosclerotic lesion in two phenotypes: proinflammatory (M1) or anti-inflammatory (M2). Paraoxonase 2 (PON2) is expressed in macrophages, and it was shown to protect against atherosclerosis. Thus, the aim of our study was to analyze the direct effect of PON2 on macrophage inflammatory phenotypes. Ex vivo studies were performed with murine peritoneal macrophages (MPM) harvested from control C57BL/6 and PON2-deficient (PON2KO) mice. PON2KO MPM showed an enhanced proinflammatory phenotype compared to the control, both in the basal state and following M1 activation by IFNγ and lipopolysaccharide (LPS). In parallel, PON2KO MPM also showed reduced anti-inflammatory responses in the basal state and also following M2 activation by IL-4. Moreover, the PON2-null MPM demonstrated enhanced phagocytosis and reactive oxygen species (ROS) production in the basal state and following M1 activation. The direct effect of PON2 was shown by transfecting human PON2 (hPON2) into PON2KO MPM. PON2 transfection attenuated the macrophages' response to M1 activation and enhanced M2 response. These PON2 effects were associated with attenuation of macrophages' abilities to phagocyte and to generate ROS. We conclude that PON2 promotes an M1 to M2 switch in macrophage phenotypes.