Punicalagin Regulates Signaling Pathways in Inflammation-Associated Chronic Diseases

Pomegranate polyphenol punicalagin as a nutraceutical for mitigating mild cognitive impairment: An overview of beneficial properties

Dementia treatment has become a global research priority, driven by the increase in the aging population. Punicalagin, the primary polyphenol found in pomegranate fruit, exhibits a variety of benefits. Today, a growing body of research is showing that punicalagin is a nutraceutical for the prevention of mild cognitive impairment (MCI). However, a comprehensive review is still lacking. The aim of this paper is to provide a comprehensive review of the physicochemical properties, origin and pharmacokinetics of punicalagin, while emphasizing the significance and mechanisms of its potential role in the prevention and treatment of MCI. Preclinical and clinical studies have demonstrated that Punicalagin possesses the potential to effectively target and enhance the treatment of MCI. Potential mechanisms by which punicalagin alleviates MCI include antioxidative damage, anti-neuroinflammation, promotion of neurogenesis, and modulation of neurotransmitter interactions. Overall, punicalagin is safer and shows potential as a therapeutic compound for the prevention and treatment of MCI, although more rigorous randomized controlled trials involving large populations are required.

Punicalagin promotes mincle-mediated phagocytosis of macrophages via the NF-κB and MAPK signaling pathways

Punicalagin (PUN) is a polyphenol derived from the pomegranate peel. It has been reported to have many beneficial effects, including anti-inflammatory, anti-oxidant, and anti-proliferation. However, the role of PUN in macrophage phagocytosis is currently unknown. In this study, we found that pre-treatment with PUN significantly enhanced phagocytosis by macrophages in a time- and dose-dependent manner in vitro. Moreover, KEGG enrichment analysis by RNA-sequencing showed that differentially expressed genes following PUN treatment were significantly enriched in phagocyte-related receptors, such as the C-type lectin receptor signaling pathway. Among the C-type lectin receptor family, Mincle (Clec4e) significantly increased at the mRNA and protein level after PUN treatment, as shown by qRT-PCR and western blotting. Small interfering RNA (siRNA) mediated knockdown of Mincle in macrophages resulted in down regulation of phagocytosis. Furthermore, western blotting showed that PUN treatment enhanced the phosphorylation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) in macrophages at the early stage. Mincle-mediated phagocytosis by PUN was inhibited by PDTC (a NF-κB inhibitor) and SB203580 (a p38 MAPK inhibitor). In addition, PUN pre-treatment enhanced phagocytosis by peritoneal and alveolar macrophages in vivo. After intraperitoneal injection of Escherichia coli (E.coli), the bacterial load of peritoneal lavage fluid and peripheral blood in PUN pre-treated mice decreased significantly. Similarly, the number of bacteria in the lung tissue significantly reduced after intranasal administration of Pseudomonas aeruginosa (PAO1). Taken together, our results reveal that PUN enhances bacterial clearance in mice by activating the NF-κB and MAPK pathways and upregulating C-type lectin receptor expression to enhance phagocytosis by macrophages.

Punicalagin attenuates hyperuricemia via restoring hyperuricemia-induced renal and intestinal dysfunctions

INTRODUCTION

It is estimated that 90% of hyperuricemia cases are attributed to the inability to excrete uric acid (UA). The two main organs in charge of excreting UA are the kidney (70%) and intestine (30%). Previous studies have reported that punicalagin (PU) could protect against kidney and intestinal damages, which makes it a potential candidate for alleviating hyperuricemia. However, the effects and deeper action mechanisms of PU for managing hyperuricemia are still unknown.

OBJECTIVE

To investigate the effect and action mechanisms of PU for ameliorating hyperuricemia.

METHODS

The effects and action mechanisms of PU on hyperuricemia were assessed using a hyperuricemia mice model. Phenotypic parameters, metabolomics analysis, and 16S rRNA sequencing were applied to explore the effect and fundamental action mechanisms inside the kidney and intestine of PU for improving hyperuricemia.

RESULTS

PU administration significantly decreased elevated serum uric acid (SUA) levels in hyperuricemia mice, and effectively alleviated the kidney and intestinal damage caused by hyperuricemia. In the kidney, PU down-regulated the expression of UA resorption protein URAT1 and GLUT9, while up-regulating the expression of UA excretion protein ABCG2 and OAT1 as mediated via the activation of MAKP/NF-κB in hyperuricemia mice. Additionally, PU attenuated renal glycometabolism disorder, which contributed to improving kidney dysfunction and inflammation. Similarly, PU increased UA excretion protein expression via inhibiting MAKP/NF-κB activation in the intestine of hyperuricemia mice. Furthermore, PU restored gut microbiota dysbiosis in hyperuricemia mice.

CONCLUSION

This research revealed the ameliorating impacts of PU on hyperuricemia by restoring kidney and intestine damage in hyperuricemia mice, and to be considered for the development of nutraceuticals used as UA-lowering agent.

Punicalagin Restricts Growth, Promotes Apoptosis, and Reduces Invasion in Human Gastric Cancer Cells

This research investigated the anticancer properties of punicalagin, a prominent bioactive polyphenol extracted from Punica granatum L, in human gastric cancer cell lines. Normal and gastric cancer cells were exposed to different doses of punicalagin for various durations. Punicalagin exhibited cytotoxic effects on gastric cancer cells in a dose- and time-dependent fashion, while sparing normal gastric epithelial cells. It is noteworthy that among the 3 gastric cancer cells, HGC-27 cells were more resistant to punicalagin than 23,132/87 and AGS cells. Furthermore, punicalagin triggered apoptosis in gastric cancer cells, evidenced by a rise in both early and late apoptotic cell percentages. Western blot analysis further revealed that punicalagin elevated the levels of activated caspase-3. Conversely, punicalagin curtailed cell invasion and reduced the expression of MMP-2, MMP-9, Snail, and Slug. From a mechanistic standpoint, Western blotting indicated that punicalagin might inhibit the Erk and NF-κB pathways, leading to apoptosis induction and the inhibition of cell invasion in gastric cancer cells. These results indicate that punicalagin promotes apoptosis and inhibits cell invasion in gastric cancer cells by activating caspase-3 and suppressing MMP-2, MMP-9, Snail, and Slug through the inhibition of the Erk and NF-κB pathways.

Punicalagin improves inflammation and oxidative stress in rat model of pelvic inflammatory disease

Pelvic inflammatory disease (PID) is one of the major public health concerns accounting for 30% of infertility and 50% of ectopic pregnancy cases due to severe inflammation and fibrosis. Punicalagin® are known to exhibit potent anti-inflammatory activity. The aim of this study was to demonstrate the anti-inflammatory and antioxidant effects of Punicalagin®, against pelvic inflammatory disease in rats. Female Sprague Dawley rats (n = 24) were divided into 6 groups (n = 4) as control, PID, prophylactic (low dose and high dose) and therapeutic group (low dose and high dose). PID model was constructed by implanting the rat cervix with mixed microbe (Escherichia Coli and Staphylococcus Aureus) solution. Prophylactic group was gavaged with 3 mg/kg (low dose) and 6 mg/kg (high dose) Punicalagin® daily starting one day before PID induction and therapeutic group was gavaged with 3 mg/kg (low dose) and 6 mg/kg (high dose) Punicalagin® daily starting 1 day after confirmation of PID model. Rats were sacrificed at the end of experiment and samples from upper genital tract were collected for ELISA, antioxidant assay and histopathological examination. According to results, obvious signs of inflammation and oxidative stress including infiltration of neutrophils and significantly raised levels of cytokines, and oxidative stress markers were observed in PID group when compared to control group. Punicalagin® significantly decreased the levels of IL-1β, catalase and lipid peroxidation in both prophylactic and therapeutic groups when compared to PID group. Punicalagin® also decreased the infiltration of leucocytes in uterus of prophylactic and therapeutic group when compared to PID group, as determined by histological examination. On basis of these results, we concluded that Punicalagin® showed anti-inflammatory and antioxidant potential in rat model of pelvic inflammatory disease and could be used as possible therapeutic agent in treatment of PID.

Anti-inflammatory effect of a pomegranate extract on LPS-stimulated HepG2 cells

Pomegranate is an important source of bioactive molecules with proven beneficial effects on human health. The aim of this study was to investigate the potential anti-inflammatory effect of a pomegranate extract (PE), obtained from the whole fruit and previously characterized by Reversed Phase-Ultra High-Pressure Liquid Chromatography-High Resolution Mass Spectrometry (RP-UHPLC-HRMS), on HepG2 human hepatocellular carcinoma cells challenged with the lipopolysaccharide (LPS). In LPS-treated cells (1 µg/ml, 24h), the PE treatment (administered at the non-cytotoxic dose of 1 µg/ml, 24h) induced a significant reduction of three key pro-inflammatory cytokines, i.e. interleukin-8 (IL-8), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α), at both gene expression (as assayed by real-time PCR) and secretion levels (by Enzyme-linked Immunosorbent Assay, ELISA). Although further in vivo studies are needed to prove its efficacy, this preliminary in vitro study suggests that the PE might be useful for ameliorating liver inflammation.

In silico and in vivo analysis of the relationship between ADHD and social isolation in pups rat model: Implication of redox mechanisms, and the neuroprotective impact of Punicalagin

Attention deficit hyperactivity disorder (ADHD) has high incidence rate among children which may be due to excessive monosodium glutamate (MSG) consumption and social isolation (SI).

AIM

We aimed to explore the relationships between MSG, SI, and ADHD development and to evaluate the neuroprotective potential of Punicalagin (PUN).

METHODS

Eighty male rat pups randomly distributed into eight groups. Group I is the control, and Group II is socially engaged rats treated with PUN. Groups III to VII were exposed to ADHD-inducing factors: Group III to SI, Group IV to MSG, and Group V to both SI and MSG. Furthermore, Groups VI to VIII were the same Groups III to V but additionally received PUN treatment.

KEY FINDINGS

Exposure to MSG and/or SI led to pronounced behavioral anomalies, histological changes and indicative of ADHD-like symptoms in rat pups which is accompanied by inhibition of the nuclear factor erythroid 2-related factor 2 (Nrf2)/Heme-oxygenase 1 (HO-1)/Glutathione (GSH) pathway, decline of the brain-derived neurotrophic factor (BDNF) expression and activation of the Toll-like receptor 4 (TLR4)/Nuclear factor kappa B (NF-kB)/NLR Family Pyrin Domain Containing 3 (NLRP3) pathway. This resulted in elevated inflammatory biomarker levels, neuronal apoptosis, and disrupted neurotransmitter equilibrium. Meanwhile, pretreatment with PUN protected against all the previous alterations.

SIGNIFICANCE

We established compelling associations between MSG consumption, SI, and ADHD progression. Moreover, we proved that PUN is a promising neuroprotective agent against all risk factors of ADHD.

Punicalagin alleviates the hyperproliferation of keratinocytes in psoriasis through inhibiting SKP2 expression

Psoriasis is a chronic inflammatory skin disorder characterized by abnormal keratinocytes proliferation and multiple immune cells infiltration in the dermis and epidermis. Although most psoriasis-related researches have been concentrated on the interleukin-23 (IL-23)/interleukin-17 (IL-17) axis, new data suggest that keratinocytes also play a pivotal role in psoriasis. Previously, we found that punicalagin (PUN), a bioactive ellagitannin extracted from Pericarpium Granati (the pericarpium of Punica granatum L.), exerts a therapeutic effect on psoriasis. However, the underlying mechanism, especially its potential modulatory effect on keratinocytes, remains obscure. Our study aims to reveal the potential regulatory effect and its underlying cellular mechanism of PUN on the hyperproliferation of keratinocytes. We used tumor necrosis factor α (TNF-α), IL-17A and interleukin-6 (IL-6) to induce abnormal proliferation of HaCaT cells (Human Keratinocytes Cells) in vitro. Then, we evaluated the effects of PUN through MTT assay, EdU staining and cell cycle detection. Finally, we explored the underlying cellular mechanisms of PUN via RNA-sequencing, WB in vitro and in vivo. Here, we found that PUN can directly and dose-dependently decrease TNF-α, IL-17A and IL-6-induced abnormal proliferation of HaCaT cells in vitro. Mechanically, PUN suppresses the hyperproliferation of keratinocytes through repressing S-phase kinase-associated protein 2 (SKP2) expression in vitro and in vivo. Moreover, overexpression of SKP2 can partly abolish PUN-mediated inhibition of aberrantly proliferative keratinocytes. These results illustrate that PUN can reduce the severity of psoriasis through directly repressing SKP2-mediated abnormal proliferation of keratinocytes, which gives new insight into the therapeutic mechanism of PUN on psoriasis. Moreover, these findings imply that PUN might be a promising drug candidate for the treatment of psoriasis.

The Impact of Punica granatum Linn and Its Derivatives on Oxidative Stress, Inflammation, and Endothelial Function in Diabetes Mellitus: Evidence from Preclinical and Clinical Studies

Diabetes mellitus is recognized as the leading contributor to cardiovascular disease and associated mortality rates worldwide. Despite the use of pharmaceutical drugs to treat diabetes, its prevalence continues to rise alarmingly. Therefore, exploring remedies with a lower toxicity profile is crucial while remaining safe and effective in addressing this global public health crisis. Punica granatum Linn (pomegranate), known for its properties and safety profile, has been investigated in applied research and preclinical and clinical trials. However, conflicting reports still exist regarding its effects in diabetes. According to our knowledge, no systematic review has been conducted to critically analyze evidence from preclinical and clinical trials simultaneously, explicitly focusing on oxidative stress, inflammation, and endothelial function in diabetes. Therefore, in this systematic review, we searched for evidence on the impact of pomegranate in diabetes using databases such as PubMed, Scopus, and Google Scholar. Our inclusion criteria were limited to studies published in English. Of the 170 retrieved studies, 46 were deemed relevant and underwent critical analysis. The analyzed evidence suggests that pomegranate has the potential to alleviate oxidative stress, inflammation, and endothelial dysfunction in diabetes. Although a beneficial impact was noted in these markers, the endothelial function evidence still requires validation through further clinical trials with a powered sample size.

The Role of Punicalagin and Its Metabolites in Atherosclerosis and Risk Factors Associated with the Disease

Atherosclerotic cardiovascular disease (ACVD) is the leading cause of death worldwide. Although current therapies, such as statins, have led to a marked reduction in morbidity and mortality from ACVD, they are associated with considerable residual risk for the disease together with various adverse side effects. Natural compounds are generally well-tolerated; a major recent goal has been to harness their full potential in the prevention and treatment of ACVD, either alone or together with existing pharmacotherapies. Punicalagin (PC) is the main polyphenol present in pomegranates and pomegranate juice and demonstrates many beneficial actions, including anti-inflammatory, antioxidant, and anti-atherogenic properties. The objective of this review is to inform on our current understanding of the pathogenesis of ACVD and the potential mechanisms underlying the beneficial actions of PC and its metabolites in the disease, including the attenuation of dyslipidemia, oxidative stress, endothelial cell dysfunction, foam cell formation, and inflammation mediated by cytokines and immune cells together with the regulation of proliferation and migration of vascular smooth muscle cells. Some of the anti-inflammatory and antioxidant properties of PC and its metabolites are due to their strong radical-scavenging activities. PC and its metabolites also inhibit the risk factors of atherosclerosis, including hyperlipidemia, diabetes mellitus, inflammation, hypertension, obesity, and non-alcoholic fatty liver disease. Despite the promising findings that have emerged from numerous in vitro, in vivo, and clinical studies, deeper mechanistic insights and large clinical trials are required to harness the full potential of PC and its metabolites in the prevention and treatment of ACVD.

Natural products in attenuating renal inflammation via inhibiting the NLRP3 inflammasome in diabetic kidney disease

Diabetic kidney disease (DKD) is a prevalent and severe complications of diabetes and serves as the primary cause of end-stage kidney disease (ESKD) globally. Increasing evidence indicates that renal inflammation is critical in the pathogenesis of DKD. The nucleotide - binding oligomerization domain (NOD) - like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most extensively researched inflammasome complex and is considered a crucial regulator in the pathogenesis of DKD. The activation of NLRP3 inflammasome is regulated by various signaling pathways, including NF- κB, thioredoxin-interacting protein (TXNIP), and non-coding RNAs (ncRNA), among others. Natural products are chemicals extracted from living organisms in nature, and they typically possess pharmacological and biological activities. They are invaluable sources for drug design and development. Research has demonstrated that many natural products can alleviate DKD by targeting the NLRP3 inflammasome. In this review, we highlight the role of the NLRP3 inflammasome in DKD, and the pathways by which natural products fight against DKD via inhibiting the NLRP3 inflammasome activation, so as to provide novel insights for the treatment of DKD.

An ellagitannin-loaded CS-PEG decorated PLGA nano-prototype promotes cell cycle arrest in colorectal cancer cells

Colorectal cancer is associated with significant morbidity and mortality worldwide. Egypt, as a developing country, has a high-rise incidence of cancer. The current study objective was to investigate the antitumor influences of ellagitannin-loaded CS-PEG-decorated PLGA nano-prototypes against human colorectal cancer cell lines (HCT 116 as well as Caco-2) in vitro. Doxorubicin (DOX), punicalin (PN), and punicalagin (PNG)-encapsulated chitosan-polyethylene glycol-decorated PLGA (PLGA-CS-PEG) nanoparticles (NPs) were described. The cytotoxicity of each preparation was evaluated using MTT assays in HCT 116 as well as Caco-2 cells during G0, G1, S, and G2 cell cycle phases. Cell cycle-related gene expression and protein levels were measured after treatment. Reactive oxygen species (ROS) levels were also measured. Both PN and PNG PLGA-CS-PEG NPs induce colon cancer cell death with cell cycle arrest in the G1 phase in vitro. Caco-2 cells were more sensitive to the nano-therapy than HCT 116 cells. Upon treatment, the ratio of Bax to Bcl-2 expression was increased following nano-therapy, with increased levels of Cas-3 and decreased expression of Bcl-2, PI3k, and NF-ĸB compared to control. The nitric oxide level (NO), a marker of ROS, was increased following nano-therapy compared to control. In conclusion, ROS-mediated cell cycle arrest can be induced by PN as well as PNG nano-therapy in cell lines of colorectal cancer.

Valorization of Punica granatum L. Leaves Extracts as a Source of Bioactive Molecules

Due to a lack of innovative valorization strategies, pomegranate processing generates a significant amount of residues with a negative environmental footprint. These by-products are a rich source of bioactive compounds with functional and medicinal benefits. This study reports the valorization of pomegranate leaves as a source of bioactive ingredients using maceration, ultrasound, and microwave-assisted extraction techniques. The phenolic composition of the leaf extracts was analyzed using an HPLC-DAD-ESI/MSn system. The extracts’ antioxidant, antimicrobial, cytotoxic, anti-inflammatory, and skin-beneficial properties were determined using validated in vitro methodologies. The results showed that gallic acid, (-)-epicatechin, and granatin B were the most abundant compounds in the three hydroethanolic extracts (between 0.95 and 1.45, 0.7 and 2.4, and 0.133 and 3.0 mg/g, respectively). The leaf extracts revealed broad-spectrum antimicrobial effects against clinical and food pathogens. They also presented antioxidant potential and cytotoxic effects against all tested cancer cell lines. In addition, tyrosinase activity was also verified. The tested concentrations (50–400 µg/mL) ensured a cellular viability higher than 70% in both keratinocyte and fibroblast skin cell lines. The obtained results indicate that the pomegranate leaves could be used as a low-cost source of value-added functional ingredients for potential nutraceutical and cosmeceutical applications.

Phytochemicals as potential target on thioredoxin-interacting protein (TXNIP) for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) are currently the major cause of death and morbidity on a global scale. Thioredoxin-interacting protein (TXNIP) is a marker related to metabolism, oxidation, and inflammation induced in CVDs. The overexpression of TXNIP is closely related to the occurrence and development of CVDs. Hence, TXNIP inhibition is critical for reducing the overactivation of its downstream signaling pathway and, as a result, myocardial cell damage. Due to the chemical variety of dietary phytochemicals, they have garnered increased interest for CVDs prevention and therapy. Phytochemicals are a source of medicinal compounds for a variety of conditions, which aids in the development of effective and safe TXNIP-targeting medications. The objective of this article is to find and virtual screen novel safe, effective, and economically viable TXNIP inhibitors from flavonoids, phenols, and alkaloids derived from foods and plants. The results of the docking study revealed that silibinin, rutin, luteolin, baicalin, procyanidin B2, hesperetin, icariin, and tilianin in flavonoids, polydatin, resveratrol, and salidroside in phenols, and neferine in alkaloids had the highest Vina scores, indicating that these compounds are the active chemicals on TXNIP. In particular, silibinin can be utilized as a lead chemical in the process of structural alteration. These dietary phytochemicals may aid in the discovery of lead compounds for the development of innovative TXNIP agents for the treatment of cardiovascular disease.

Punica granatum L. Polyphenolic Extract as an Antioxidant to Prevent Kidney Injury in Metabolic Syndrome Rats

Introduction

Obesity and metabolic syndrome (MetS) constitute a rapidly increasing health problem and contribute to the development of multiple comorbidities like acute and chronic kidney disease. Insulin resistance, inappropriate lipolysis, and excess of free fatty acids (FFAs) are associated with glomerulus hyperfiltration and atherosclerosis. The important component of MetS, oxidative stress, is also involved in the destabilization of kidney function and the progression of kidney injury. Natural polyphenols have the ability to reduce the harmful effect of reactive oxygen and nitrogen species (ROS/RNS). Extract derived from Punica granatum L. is rich in punicalagin that demonstrates positive effects in MetS and its associated diseases. The aim of the study was to investigate the effect of bioactive substances of pomegranate peel to kidney damage associated with the MetS.

Methods

In this study, we compared biomarkers of oxidative stress in kidney tissue of adult male Zucker Diabetic Fatty (ZDF) rats with MetS and healthy controls that were treated with Punica granatum L. extract at a dose of 100 or 200 mg/kg. Additionally, we evaluated the effect of polyphenolic extract on kidney injury markers and remodeling. The concentration of ROS/RNS, oxLDL, glutathione (GSH), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), metalloproteinase 2 and 9 (MMP-2, MMP-9), and the activity of superoxide dismutase (SOD) and catalase (CAT) were measured.

Results

The data showed significant differences in oxidative stress markers between treated and untreated MetS rats. ROS/RNS levels, oxLDL concentration, and SOD activity were lower, whereas CAT activity was higher in rats with MetS receiving polyphenolic extract. After administration of the extract, markers for kidney injury (NGAL, KIM-1) decreased.

Conclusion

Our study confirmed the usefulness of pomegranate polyphenols in the treatment of MetS and the prevention of kidney damage. However, further, more detailed research is required to establish the mechanism of polyphenol protection.

Antibiofilm effects of punicalagin against Staphylococcus aureus in vitro

Staphylococcus aureus is a common foodborne pathogen which can form biofilms to help them resist to antimicrobials. It brings great harm to human health. Punicalagin has good antimicrobial activities against S. aureus, but its effect on biofilm formation has not been clearly illustrated. The aim of this study was to explore the antibiofilm effects of punicalagin against S. aureus. Results showed that punicalagin did not significantly interfere with the growth of S. aureus at the concentrations of 1/64 MIC to 1/16 MIC. The biomass and metabolic activity of biofilms were significantly reduced when exposed to sub-inhibitory concentrations of punicalagin. The number of viable cells in the biofilms was also decreased after punicalagin treatment. Scanning electron microscopy and confocal laser scanning microscopy images confirmed that punicalagin damaged the structure of biofilms. The antibiofilm mechanism was partly due to the modification of the cell surface which led to the reduction of cell surface hydrophobicity. These findings suggest that punicalagin has the potential to be developed as an alternative to control S. aureus biofilms.

Characterization and bioactivity of extracellular vesicles isolated from pomegranate

In the current study, extracellular vesicles from pomegranate juice (PgEVs) were isolated for the first time using size exclusion chromatography (SEC). This method permitted us to obtain highly enriched EV samples without most of the non-EV co-isolated proteins. The characterization of PgEVs through nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) allowed the determination of vesicles' concentration/volume, size, and morphology. It was confirmed from the analytical data that PgEVs contain a homogeneous population of vesicles, with a dimension and structure comparable to plant-derived EVs. Proteomic analyses by LC-MS/MS led to the characterization of 131 proteins, and several of them were related commonly to the biogenesis and transport of EVs, and/or proposed as EV markers. PgEVs exerted anti-inflammatory, antioxidant and wound-healing effects when added to the in vitro cultures of monocytic (THP-1) and intestinal (Caco-2) cell lines, respectively.

Punicalagin Protects against the Development of Methotrexate-Induced Hepatotoxicity in Mice via Activating Nrf2 Signaling and Decreasing Oxidative Stress, Inflammation, and Cell Death

Despite its effectiveness in treating inflammatory diseases and various malignancies, methotrexate (MTX) is well known to cause hepatotoxicity, which involves increased oxidative stress and inflammation, limiting its clinical use. Herein, we looked into the effect of punicalagin (PU), a polyphenolic molecule having a variety of health-promoting attributes, on MTX-induced hepatotoxicity in mice. PU (25 and 50 mg/kg/day) was given orally to the mice for 10 days, while a single dose of MTX (20 mg/kg) was injected intraperitoneally (i.p.) at day 7. The MTX-induced liver damage was demonstrated by remarkably higher transaminases (ALT and AST), ALP, and LDH, as well as significant histological alterations in hepatic tissues. MTX-injected mice also demonstrated increases in hepatic oxidative stress markers, including malondialdehyde (MDA) and nitric oxide (NO), with a concordant drop in glutathione (GSH) content and superoxide dismutase (SOD) and catalase (CAT) activities. PU significantly attenuated the MTX-induced serum transaminases, ALP and LDH elevations, and hepatic oxidative stress measures and boosted antioxidant defenses in the liver. Moreover, the liver of MTX-treated mice showed increases in NF-κB p65 expression, pro-inflammatory cytokine (IL-6 and TNF-α) levels, and pro-apoptotic protein (caspase-3 and Bax) expression, whereas Bcl-2 and Nrf2 expressions were reduced, which were all attenuated by PU treatment. Collectively, PU inhibits oxidative damage, inflammation, and apoptosis and upregulates Nrf2 in the liver of MTX-induced mice. Thus, these findings suggest that PU may have great therapeutic potential for the prevention of MTX-induced hepatotoxicity, pending further exploration in upcoming studies.

Punica granatum as Anticandidal and Anti-HIV Agent: An HIV Oral Cavity Potential Drug

The oral cavity is crucial from diagnosis to adherence to HAART therapy in the HIV/AIDS population; consequently, drugs that can maintain healthy conditions in the oral cavity are necessary for patients with HIV/AIDS. Punica granatum (pomegranate) is a tree that has been employed extensively for centuries in the traditional medicine of ancient cultures for the treatment of a wide range of diseases, including oral and dental diseases. In recent decades, its potent anticandidal properties have been shown, especially on Candida albicans, the cause of the most common clinical manifestation in HIV patients. The present work contributes to the review of the anti-HIV and anticandidal properties of the plant species P. granatum as involved with the oral cavity. The literature reviewed revealed that crude extracts of pomegranate and its main isolated compounds possess inhibitory activity on different HIV targets, including binding viral proteins and the three replicative HIV enzymes. In addition, in the literature reviewed, pomegranate exhibited anticandidal effects on 10 different species. Thus, pomegranate appears to be an excellent candidate to explore and incorporate into the treatment of the oral cavity of HIV/AIDS patients, in that, in addition to its pharmacological effects such as antiviral and anticandidal, pomegranate represents an easily available, inexpensive, and safe natural source.

Punicalagin Attenuates LPS-Induced Inflammation and ROS Production in Microglia by Inhibiting the MAPK/NF-κB Signaling Pathway and NLRP3 Inflammasome Activation

Purpose

Neurodegenerative diseases are associated with neuroinflammation along with activation of microglia and oxidative stress, but currently lack effective treatments. Punicalagin is a natural bio-sourced product that exhibits anti-inflammatory effects on several chronic diseases; however, the anti-inflammatory and anti-oxidative effects on microglia have not been well examined. This study aimed to investigate the effects of punicalagin on LPS-induced inflammatory responses, NLRP3 inflammasome activation, and the production of ROS using murine microglia BV2 cells.

Methods

BV2 cells were pre-treated with punicalagin following LPS treatment to induce inflammation. The secretion of NO and PGE₂ was analyzed by Griess reagent and ELISA respectively, while the expressions of iNOS, COX-2, STAT3, ERK, JNK, and p38 were analyzed using Western blotting, the production of IL-6 was measured by ELISA, and the activity of NF-κB was detected using promoter reporter assay. To examine whether punicalagin affects NLRP3 inflammasome activation, BV2 cells were stimulated with LPS and then treated with ATP or nigericin. The secretion of IL-1β was measured by ELISA. The expressions of NLRP3 inflammasome-related proteins and phospho IκBα/IκBα were analyzed using Western blotting. The production of intracellular and mitochondrial ROS was analyzed by flow cytometry.

Results

Our results showed that punicalagin attenuated inflammation with reduction of pro-inflammatory mediators and cytokines including iNOS, COX-2, IL-1β, and reduction of IL-6 led to inhibition of STAT3 phosphorylation by LPS-induced BV2 cells. Punicalagin also suppressed the ERK, JNK, and p38 phosphorylation, attenuated NF-κB activity, inhibited the activation of the NLRP3 inflammasome, and reduced the production of intracellular and mitochondrial ROS by LPS-induced BV2 cells.

Conclusion

Our results demonstrated that punicalagin attenuated LPS-induced inflammation through suppressing the expression of iNOS and COX-2, inhibited the activation of MAPK/NF-κB signaling pathway and NLRP3 inflammasome, and reduced the production of ROS in microglia, suggesting that punicalagin might have the potential in treating neurodegenerative diseases.