Synthesis and Biological Activities of Scleropentaside D.

We report the first total synthesis of scleropentaside D, a unique C-glycosidic ellagitannin, from the ketal derivative of scleropentaside A employing site-selective O4-protection of C-acyl glycoside and copper-catalyzed oxidative coupling reaction of galloyl groups as the key steps. Our study confirms the proposed structure of this natural product, scleropentaside D, and demonstrates its effectiveness as an inhibitor of α-glycosidase.

Heterogeneity of transport and metabolism of Tormentillae rhizoma constituents across human intestinal epithelium cellular model.

Tormentilla erecta (L.) Raeusch is a widespread plant in Europe and Western Asia. Its rhizomes (Tormentilae rhizoma) are the main ingredient of herbal alcoholic beverages and can be used as a natural preservative in beer production. Apart from its unique taste qualities, therapeutic properties in gastrointestinal tract ailments are attributed to the tincture obtained from Tormentillae rhizoma. The presented research aimed to determine the mutual relationship between the components of Tormentillae tincture, present in popular alcoholic beverages, and intestinal epithelium (Caco-2 cell monolayers). A comprehensive qualitative and quantitative analysis of the tincture was performed, including the determination of condensed and hydrolyzable tannins as well as triterpenoids (UHPLC-DAD-MS/MS). Incubation of the tincture with Caco-2 monolayers has shown that only triterpenes pass through the monolayer, while condensed tannins are mainly bound to the monolayer surface. Ellagic acid derivatives were the only components of the Tormentillae tinctura being metabolized by cell monolayers to the compounds not previously described in the literature, which may be crucial in the treatment of intestinal diseases with inflammatory background.

Recovery of Ellagic Acid from Pomegranate Peels with the Aid of Ultrasound-Assisted Alkaline Hydrolysis.

The pomegranate processing industry generates worldwide enormous amounts of by-products, such as pomegranate peels (PPs), which constitute a rich source of phenolic compounds. In this view, PPs could be exploited as a sustainable source of ellagic acid, which is a compound that possesses various biological actions. The present study aimed at the liberation of ellagic acid from its bound forms via ultrasound-assisted alkaline hydrolysis, which was optimized using response surface methodology. The effects of duration of sonication, solvent:solid ratio, and NaOH concentration on total phenol content (TPC), antioxidant activity, and punicalagin and ellagic acid content were investigated. Using the optimum hydrolysis conditions (i.e., 32 min, 1:48 v/w, 1.5 mol/L NaOH), the experimental responses were found to be TCP: 4230 ± 190 mg GAE/100 g dry PPs; AABTS: 32,398 ± 1817 µmol Trolox/100 g dry PPs; ACUPRAC: 29,816 ± 1955 µmol Trolox/100 g dry PPs; 59 ± 3 mg punicalagin/100 g dry PPs; and 1457 ± 71 mg ellagic acid/100 g dry PPs. LC-QTOF-MS and GC-MS analysis of the obtained PP extract revealed the presence of various phenolic compounds (e.g., ellagic acid), organic acids (e.g., citric acid), sugars (e.g., fructose) and amino acids (e.g., glycine). The proposed methodology could be of use for food, pharmaceutical, and cosmetics applications, thus reinforcing local economies.

Corilagin relieves atherosclerosis via the toll-like receptor 4 signaling pathway in vascular smooth muscle cells.

INTRODUCTION: Corilagin possesses a diverse range of pharmacologic bioactivities. However, the specific protective effects and mechanisms of action of corilagin in the context of atherosclerosis remain unclear. In this study, we investigated the impact of corilagin on the toll-like receptor (TLR)4 signaling pathway in a mouse vascular smooth muscle cell line (MOVAS) stimulated by oxidized low-density lipoprotein (ox-LDL). Additionally, we examined the effects of corilagin in Sprague-Dawley rats experiencing atherosclerosis. METHODS: The cytotoxicity of corilagin was assessed using the CCK8 assay. MOVAS cells, pre-incubated with ox-LDL, underwent treatment with varying concentrations of corilagin. TLR4 expression was modulated by either downregulation through small interfering (si)RNA or upregulation via lentivirus transfection. Molecular expression within the TLR4 signaling pathway was analyzed using real-time polymerase chain reaction (PCR) and Western blotting. The proliferation capacity of MOVAS cells was determined through cell counting. In a rat model, atherosclerosis was induced in femoral arteries using an improved guidewire injury method, and TLR4 expression in plaque areas was assessed using immunofluorescence. Pathological changes were examined through hematoxylin and eosin staining, as well as Oil-Red-O staining. RESULTS: Corilagin demonstrated inhibitory effects on the TLR4 signaling pathway in MOVAS cells pre-stimulated with ox-LDL, consequently impeding the proliferative impact of ox-LDL. The modulation of TLR4 expression, either through downregulation or upregulation, similarly influenced the expression of downstream molecules. In an in vivo context, corilagin exhibited the ability to suppress TLR4 and MyD88 expression in the plaque lesion areas of rat femoral arteries, thereby alleviating the formation of atherosclerotic plaques. CONCLUSION: Corilagin can inhibit the TLR4 signaling pathway in VSMCs, possibly by downregulating TLR4 expression and, consequently, relieving atherosclerosis.

Study on Quality Characteristic of Chebulae Fructus and Its Adulterants and Degradation Pathway of Hydrolyzable Tannins.

Chebulae Fructus (CF) is known as one of the richest sources of hydrolyzable tannins (HTs). In this study, ultra-performance liquid chromatography coupled with a photodiode array detector method was established for simultaneous determination of the 12 common phenolcarboxylic and tannic constituents (PTCs). Using this method, quantitative analysis was accomplished in CF and other four adulterants, including Terminaliae Belliricae Fructus, Phyllanthi Fructus, Chebulae Fructus Immaturus, and Canarii Fructus. Based on a quantitative analysis of the focused compounds, discrimination of CF and other four adulterants was successfully accomplished by hierarchical cluster analysis and principal component analysis. Additionally, the total contents of the 12 compounds that we focused on in this study were unveiled as 148.86 mg/g, 96.14 mg/g, and 18.64 mg/g in exocarp, mesocarp, and endocarp and seed of CF, respectively, and PTCs were witnessed to be the most abundant in the exocarp of CF. Noticeably, the HTs (chebulagic acid, chebulanin acid, chebulinic acid, and punicalagin) were observed to be ultimately degraded to chebulic acid, gallic acid, and ellagic acid during sunlight-drying of the fresh fruits. As a result, our study indicated that CF and its adulterants could be distinguished by the observed 12 PTCs, which were mainly distributed in the exocarp of the fruits. The HTs were prone to degrade into the three simple phenolcarboxylic acids during drying or processing, allowing us to obtain a more comprehensive understanding of the PTCs, with great significance in the improved quality of CF and related products.

Investigation into the Anti-Acne Effects of Castanea sativa Mill Leaf and Its Pure Ellagitannin Castalagin in HaCaT Cells Infected with Cutibacterium acnes.

Acne vulgaris is a prevalent skin disorder affecting many young individuals, marked by keratinization, inflammation, seborrhea, and colonization by Cutibacterium acnes (C. acnes). Ellagitannins, known for their antibacterial and anti-inflammatory properties, have not been widely studied for their anti-acne effects. Chestnut (Castanea sativa Mill., C. sativa), a rich ellagitannin source, including castalagin whose acne-related bioactivity was previously unexplored, was investigated in this study. The research assessed the effect of C. sativa leaf extract and castalagin on human keratinocytes (HaCaT) infected with C. acnes, finding that both inhibited IL-8 and IL-6 release at concentrations below 25 µg/mL. The action mechanism was linked to NF-κB inhibition, without AP-1 involvement. Furthermore, the extract displayed anti-biofilm properties and reduced CK-10 expression, indicating a potential role in mitigating inflammation, bacterial colonization, and keratosis. Castalagin's bioactivity mirrored the extract's effects, notably in IL-8 inhibition, NF-κB inhibition, and biofilm formation at low µM levels. Other polyphenols, such as flavonol glycosides identified via LC-MS, might also contribute to the extract's biological activities. This study is the first to explore ellagitannins' potential in treating acne, offering insights for developing chestnut-based anti-acne treatments pending future in vivo studies.

Exploring potential inhibitors of acetylcholinesterase, lactate dehydrogenases, and glutathione reductase from Hagenia abyssinica (Bruce) J.F. Gmel. based on multi-target ultrafiltration-liquid chromatography-mass spectrometry and molecular docking.

ETHNOPHARMACOLOGICAL RELEVANCE: Parasitic infections impose a significant burden on public health worldwide. European pharmacopoeia records and ethnopharmacological studies indicate that Hagenia abyssinica (Bruce) J.F. Gmel. has traditionally been used to treat a variety of parasitic infections, while the potential antiparasitic compounds remain ambiguous. AIM OF THE STUDY: Acetylcholinesterase (AChE), lactate dehydrogenases (LDH), and glutathione reductase (GR) are the key target enzymes in the survival of parasites. The aim of our work was to screen antiparasitic compounds targeting AChE, LDH, and GR from H. abyssinica. MATERIALS AND METHODS: Ultrafiltration-liquid chromatography-mass spectrometry (UF-LC-MS) combined with molecular docking was used in this study. Therein, the alamarBlue® and Ellman's methods were employed to reveal the antitrypanosomal effect and AChE inhibitory activity. Meanwhile, the UF-LC-MS was carried out to screen the potential active compounds from H. abyssinica. Subsequently, molecular docking was performed to evaluate the binding mechanisms of these active compounds with AChE, LDH, and GR. Finally, the AChE inhibitory activity of potential inhibitors was detected in vitro. RESULTS: H. abyssinica exhibited significant antitrypanosomal and AChE inhibitory activity. Corilagin, brevifolin carboxylic acid, brevifolin, quercetin, and methyl ellagic acid were recognized as potential AChE inhibitors by UF-LC-MS, while methyl brevifolin carboxylate was identified as AChE, LDH, and GR multi-target inhibitor, with binding degree ranged from 20.96% to 49.81%. Molecular docking showed that these potential inhibitors had a strong affinity with AChE, LDH, and GR, with binding energies ranging from -6.98 to -9.67 kcal/mol. These findings were further supported by the observation that corilagin, quercetin, brevifolin carboxylic acid, and methyl brevifolin carboxylate displayed significant AChE inhibitory activity compared with the positive control (gossypol, 0.42 ± 0.04 mM), with IC50 values of 0.15 ± 0.05, 0.56 ± 0.03, 0.99 ± 0.01, and 1.02 ± 0.03 mM, respectively. CONCLUSIONS: This study confirms the antiparasitic potential of H. abyssinica, supporting the traditional use of H. abyssinica in local ethnopharmacology to treat parasites. At the same time, corilagin, brevifolin carboxylic acid, brevifolin, quercetin, methyl ellagic acid, and methyl brevifolin carboxylate exert their anti-parasitic effects by inhibiting AChE, LDH, and GR, and they are expected to be natural lead compounds for the treatment of parasitic diseases.

Corilagin alleviates atherosclerosis by inhibiting NLRP3 inflammasome activation via the Olfr2 signaling pathway in vitro and in vivo.

Introduction: Atherosclerosis, a leading cause of global cardiovascular mortality, is characterized by chronic inflammation. Central to this process is the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, which significantly influences atherosclerotic progression. Recent research has identified that the olfactory receptor 2 (Olfr2) in vascular macrophages is instrumental in driving atherosclerosis through NLRP3- dependent IL-1 production. Methods: To investigate the effects of Corilagin, noted for its anti-inflammatory attributes, on atherosclerotic development and the Olfr2 signaling pathway, our study employed an atherosclerosis model in ApoE-/- mice, fed a high-fat, high-cholesterol diet, alongside cellular models in Ana-1 cells and mouse bone marrow-derived macrophages, stimulated with lipopolysaccharides and oxidized low-density lipoprotein. Results: The vivo and vitro experiments indicated that Corilagin could effectively reduce serum lipid levels, alleviate aortic pathological changes, and decrease intimal lipid deposition. Additionally, as results showed, Corilagin was able to cut down expressions of molecules associated with the Olfr2 signaling pathway. Discussion: Our findings indicated that Corilagin effectively inhibited NLRP3 inflammasome activation, consequently diminishing inflammation, macrophage polarization, and pyroptosis in the mouse aorta and cellular models via the Olfr2 pathway. This suggests a novel therapeutic mechanism of Corilagin in the treatment of atherosclerosis.

Punicalagin attenuates isoproterenol-induced myocardial infarction through nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1-mediated inhibition of inflammation and cardiac stress markers in experimental animal models.

Myocardial infarction (MI) is a significant global health issue and the leading cause of death. Myocardial infarction (MI) is characterized by events such as damage to heart cells and stress generated by inflammation. Punicalagin (PCN), a naturally occurring bioactive compound found in pomegranates, exhibits a diverse array of pharmacological effects against many disorders. This study aimed to assess the preventive impact of PCN, with its potential anti-inflammatory and antioxidant properties, on myocardial injury caused by isoproterenol (ISO) in rats and elucidate the possible underlying mechanisms. Experimental rats were randomly categorized into four groups: control group (fed a regular diet for 15 days), PCN group (orally administered PCN at 50 mg/kg body weight (b.w.) for 15 days), ISO group (subcutaneously administered ISO (85 mg/kg b.w.) on days 14 and 15 to induce MI), and PCN+ISO group (orally preadministered PCN (50 mg/kg b.w.) for 15 days and administered ISO (85 mg/kg b.w.) on days 14 and 15). The rat cardiac tissue was then investigated for cardiac marker, oxidative stress marker, and inflammatory marker expression levels. PCN prevented ISO-induced myocardial injury, suppressing the levels of creatine kinase-myocardial band, C-reactive protein, homocysteine, cardiac troponin T, and cardiac troponin I in the rats. Moreover, PCN treatment reversed (P<0.01) the ISO-induced increase in blood pressure, attenuated lipid peroxidation markers, and depleted both enzymatic and nonenzymatic markers in the rats. Additionally, PCN inhibited (P<0.01) ISO-induced overexpression of oxidative stress markers (p-38, p-c-Jun N-terminal kinase, and p-extracellular signal-regulated kinase 1), inflammatory markers (nuclear factor-kappa B, tumor necrosis factor-alpha, and interleukin-6), and matrix metalloproteinases and decreased the levels (P<0.01) of apoptosis proteins in the rats. Nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1 (Nrf2/Sirt1) is a major cellular defense protein that regulates and scavenges oxidative toxic substances through apoptosis. Therefore, overexpression of Nrf2/Sirt1 to inhibit inflammation and oxidative stress is considered a novel target for preventing MI. PCN also significantly enhanced the expression of Nrf2/Sirt1 in ISO-induced rats. Histopathological analyses of cardiac tissue revealed that PCN treatment exhibited a protective effect on the heart tissue, mitigating damage. These findings show that by activating the Nrf2/Sirt1 pathway, PCN regulates oxidative stress, inflammation, and apoptosis, hence providing protection against ISO-induced myocardial ischemia.

Rapid and green quantification of phloridzin and trilobatin in Lithocarpus litseifolius (Hance) Chun (sweet tea) using an online pressurized liquid extraction high-performance liquid chromatography at equal absorption wavelength method.

Sweet tea is a functional herbal tea with anti-inflammatory, anti-diabetic, and other effects, in which phloridzin and trilobatin are two functional compounds. However, the current methods for their quantification are time-consuming, costly, and environmentally unfriendly. In this paper, we propose a rapid method that integrates online pressurized liquid extraction and high-performance liquid chromatography featuring a superficially porous column for fast separation. Moreover, we employ an equal absorption wavelength method to eliminate using multiple standard solutions and relative calibration factors. Our verification process corroborated the technique's selectivity, accuracy, precision, linearity, and detection limitations. Separately, our methodology demonstrated excellent analytical efficiency, cost-effectiveness, and environmental friendliness. Practical application using six distinct batches of sweet tea samples yielded results in congruence with the external standard method. The analytical rate of this technique is up to over 18 times faster than traditional methods, and organic solvent consumption has been reduced to less than 1.5 mL. Therefore, this method provides a valuable way to achieve quality control and green analysis of sweet tea and other herbal teas.

Geraniin Alleviates Inflammation in Caco-2 Cells and Dextran Sulfate Sodium-Induced Colitis Mice by Targeting IL-1ß.

IL-1ß is an important cytokine implicated in the progression of inflammatory bowel disease (IBD) and intestinal barrier dysfunction. The polyphenolic compound, geraniin, possesses bioactive properties, such as antitumor, antioxidant, anti-inflammatory, antihypertensive, and antiviral activities; however, its IL-1ß-targeted anticolitis activity remains unclear. Here, we evaluated the inhibitory effect of geraniin in IL-1ß-stimulated Caco-2 cells and a dextran sulfate sodium (DSS)-induced colitis mouse model. Geraniin blocked the interaction between IL-1ß and IL-1R by directly binding to IL-1ß and inhibited the IL-1ß activity. It suppressed IL-1ß-induced intestinal tight junction damage in human Caco-2 cells by inhibiting IL-1ß-mediated MAPK, NF-kB, and MLC activation. Moreover, geraniin administration effectively reduced colitis symptoms and attenuated intestinal barrier injury in mice by suppressing elevated intestinal permeability and restoring tight junction protein expression through the inhibition of MAPK, NF-kB, and MLC activation. Thus, geraniin exhibits anti-IL-1ß activity and anticolitis effect by hindering the IL-1ß and IL-1R interaction and may be a promising therapeutic anti-IL-1ß agent for IBD treatment.

Sulfone-based human liver pyruvate kinase inhibitors - Design, synthesis and in vitro bioactivity.

Non-alcoholic fatty liver disease (NAFLD) is a prevalent pathological condition characterised by the accumulation of fat in the liver. Almost one-third of the global population is affected by NAFLD, making it a significant health concern. However, despite its prevalence, there is currently no approved drug specifically designed for the treatment of NAFLD. To address this critical gap, researchers have been investigating potential targets for NAFLD drug development. One promising candidate is the liver isoform of pyruvate kinase (PKL). In recent studies, Urolithin C, an allosteric inhibitor of PKL, has emerged as a potential lead compound for therapeutic intervention. Building upon this knowledge, our team has conducted a comprehensive structure-activity relationship of Urolithin C. In this work, we have employed a scaffold-hopping approach, modifying the urolithin structure by replacing the urolithin carbonyl with a sulfone moiety. Our structure-activity relationship analysis has identified the sulfone group as particularly favourable for potent PKL inhibition. Additionally, we have found that the presence of catechol moieties on the two aromatic rings further improves the inhibitory activity. The most promising inhibitor from this new series displayed nanomolar inhibition, boasting an IC50 value of 0.07 µM. This level of potency rivals that of urolithin D and significantly surpasses the effectiveness of urolithin C by an order of magnitude. To better understand the molecular interactions underlying this inhibition, we obtained the crystal structure of one of the inhibitors complexed with PKL. This structural insight served as a valuable reference point, aiding us in the design of inhibitors.

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.

Genomic basis of the distinct biosynthesis of ß-glucogallin, a biochemical marker for hydrolyzable tannin production, in three oak species.

Hydrolyzable tannins (HTs), predominant polyphenols in oaks, are widely used in grape wine aging, feed additives, and human healthcare. However, the limited availability of a high-quality reference genome of oaks greatly hampered the recognition of the mechanism of HT biosynthesis. Here, high-quality reference genomes of three Asian oak species (Quercus variabilis, Quercus aliena, and Quercus dentata) that have different HT contents were generated. Multi-omics studies were carried out to identify key genes regulating HT biosynthesis. In vitro enzyme activity assay was also conducted. Dual-luciferase and yeast one-hybrid assays were used to reveal the transcriptional regulation. Our results revealed that ß-glucogallin was a biochemical marker for HT production in the cupules of the three Asian oaks. UGT84A13 was confirmed as the key enzyme for ß-glucogallin biosynthesis. The differential expression of UGT84A13, rather than enzyme activity, was the main reason for different ß-glucogallin and HT accumulation. Notably, sequence variations in UGT84A13 promoters led to different trans-activating activities of WRKY32/59, explaining the different expression patterns of UGT84A13 among the three species. Our findings provide three high-quality new reference genomes for oak trees and give new insights into different transcriptional regulation for understanding ß-glucogallin and HT biosynthesis in closely related oak species.

Development of Methodologies toward the Unified Synthesis of Ellagitannins.

Ellagitannins, a class of polyphenols with divergent structures, have attracted considerable attention from synthetic organic chemists. The basic structures in ellagitannins contain esters of D-glucose with galloyl or hexahydroxyldiphenoyl groups, as well as diaryl ether structures. Thus, the synthesis methodologies of such components have been developed by various groups, including our group. This review describes the synthetic methods reported by our group during 2017-2023, aimed at increasing the number of ellagitannins that can be chemically synthesized. In addition, recent related reports are introduced.

Synthesis, characterization, pharmacological and computational evaluation of hyaluronic acid modified chebulinic acid encapsulated chitosan nanocomposite for cancer therapy.

The purpose of this study was to produce hyaluronic acid customized nanoparticles with chitosan for the delivery of chebulinic acid (CLA) to enhance its anticancer potential against breast cancer. A significant portion of CLA was encapsulated (89.72 ± 4.38 %) and loaded (43.15 ± 5.61 %) within hybrid nanoparticles. The colloidal hybrid nanoparticles demonstrated a polydispersity index (PDI) of about 0.379 ± 0.112, with zeta capacitance of 32.69 ± 5.12 (mV), and an average size of 115 ± 8 (nm). It was found that CLA-CT-HA-NPs had stronger anticancer effects on MCF-7 cells (IC50 = 8.18 ± 3.02 µM) than pure CLA (IC50 = 17.15 ± 5.11 µM). The initial cytotoxicity findings were supported by additional investigations based on comet assay and flow cytometry analysis. Tumor remission and survival were evaluated in five separate groups of mice. When juxtaposed with pure CLA (3.17 ± 0.419 %), CLA-CT-HA-NPs improved survival rates and reduced tumor burden by 3.76 ± 0.811(%). Furthermore, in-silico molecular docking investigations revealed that various biodegradable polymers had several levels of compatibility with CLA. The outcomes of this study might potentially served as an effective strategy for delivering drugs in the context of breast cancer therapy.

Punicalagin from pomegranate ameliorates TNF-α/IFN-γ-induced inflammatory responses in HaCaT cells via regulation of SIRT1/STAT3 axis and Nrf2/HO-1 signaling pathway.

Punicalagin (PUN) was isolated from the peel of pomegranate (Punica granatum L.), is a polyphenol with anti-inflammatory, hepatoprotective, and antioxidant activities. However, it remains unclear whether PUN alleviates the inflammation and anti-inflammatory mechanisms in pro-inflammatory cytokines-induced human keratinocyte HaCaT cells. Here, we investigated that tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) mixture-stimulated HaCaT cells were treated with various concentrations of PUN, followed by analyzed the expression of inflammation-related mediators and evaluate anti-inflammatory-related pathways. Our results demonstrated that PUN ≤ 100 µM did not reduce HaCaT cell viability, and PUN ≥ 3 µM was sufficient to decrease interleukin-6 (IL-6), IL-8, monocyte chemoattractant protein-1 (MCP-1), chemokine ligand 5 (CCL5), CCL17 and CCL20 concentrations. We found that PUN ≥ 10 µM and ≥ 3 µM significantly increased sirtuin 1 (SIRT1) expression and inhibited signal transducer and activator of transcription 3 (STAT3) phosphorylation, respectively. PUN downregulated inflammation-related proteins cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), enhanced nuclear factor erythroid-2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) expression. Moreover, PUN decreased intercellular adhesion molecule-1 (ICAM-1) expression and inhibited monocyte adhesion to inflamed HaCaT cells. PUN also suppressed inflammatory-related pathways, including mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways in TNF-α/IFN-γ- stimulated HaCat cells. Collectively, there is significant evidence that PUN has effective protective defenses against TNF-α/IFN-γ-induced skin inflammation by enhancing SIRT1 to mediate STAT3 and Nrf2/HO-1 signaling pathway.

Geraniin restricts inflammasome activation and macrophage pyroptosis by preventing the interaction between ASC and NLRP3 to exert anti-inflammatory effects.

Geraniin, a chemical component of the traditional Chinese medicine geranii herba, possesses anti-inflammatory and anti-oxidative activities. However, its anti-inflammatory role in managing NLRP3 inflammasome and pyroptosis remains to be elucidated. To investigate the anti-inflammation mechanism of geraniin, LPS-primed macrophages were incubated with classical activators of NLRP3 inflammasome (such as ATP, Nigericin, or MSU crystals), and MSU crystals were injected into the ankle joints of mice to establish an acute gouty arthritis model. The propidium iodide (PI) staining results showed that geraniin could restrain cell death in the ATP- or nigericin-stimulated bone marrow-derived macrophages (BMDMs). Geraniin decreased the release of lactate dehydrogenase (LDH) and interleukin (IL)-1ß from cytoplasm to cell supernatant. Geraniin also inhibited the expression of caspase-1 p20, IL-1ß in cell supernatant and N-terminal of gasdermin D (GSDMD-NT) while blocking the oligomerization of ASC to form speck. The inhibitory effects of geraniin on caspase-1 p20, IL-1ß, GSDMD-NT, and ASC speck were not observed in NLRP3 knockout (NLRP3-/-) BMDMs. Hence, the resistance of geraniin to inflammasome and pyroptosis was contingent upon NLRP3 presence. Geraniin reduced reactive oxygen species (ROS) production and maintained mitochondrial membrane potential while preventing interaction between ASC and NLRP3 protein. Additionally, geraniin diminished MSU crystal-induced mouse ankle joint swelling and IL-1ß expression. Geraniin blocked the recruitment of neutrophils and macrophages to the synovium of joints. Our results demonstrate that geraniin prevents the assembly of ASC and NLRP3 through its antioxidant effect, thereby inhibiting inflammasome activation, pyroptosis, and IL-1ß release to provide potential insights for gouty arthritis targeted therapy.

Punicalagin, a pomegranate polyphenol sensitizes the activity of antibiotics against three MDR pathogens of the Enterobacteriaceae.

BACKGROUND: Multidrug resistance (MDR) in the family Enterobacteriaceae is a perniciously increasing threat to global health security. The discovery of new antimicrobials having the reversing drug resistance potential may contribute to augment and revive the antibiotic arsenal in hand. This study aimed to explore the anti-Enterobacteriaceae capability of bioactive polyphenols from Punica granatum (P. granatum) and their co-action with antibiotics against clinical isolates of Enterobacteriaceae predominantly prevalent in South Asian countries. METHODS: The Kandhari P. granatum (Pakistani origin) extracts were tested for anti-Enterobacteriaceae activity by agar well diffusion assay against MDR Salmonella enterica serovar Typhi, serovar Typhimurium and Escherichia coli. Predominant compounds of active extract were determined by mass spectrometry and screened for bioactivity by agar well diffusion and minimum inhibitory concentration (MIC) assay. The active punicalagin was further evaluated at sub-inhibitory concentrations (SICs) for coactivity with nine conventional antimicrobials using a disc diffusion assay followed by time-kill experiments that proceeded with SICs of punicalagin and antimicrobials. RESULTS: Among all P. granatum crude extracts, pomegranate peel methanol extract showed the largest inhibition zones of 25, 22 and 19 mm, and the MICs as 3.9, 7.8 and 7.8 mg/mL for S. typhi, S. typhimurium and E. coli, respectively. Punicalagin and ellagic acid were determined as predominant compounds by mass spectrometry. In plate assay, punicalagin (10 mg/mL) was active with hazy inhibition zones of 17, 14, and 13 mm against S. typhi, S. typhimurium and E. coli, respectively. However, in broth dilution assay punicalagin showed no MIC up to 10 mg/mL. The SICs 30 µg, 100 µg, and 500 µg of punicalagin combined with antimicrobials i.e., aminoglycoside, ß-lactam, and fluoroquinolone act in synergy against MDR strains with % increase in inhibition zone values varying from 3.4 ± 2.7% to 73.8 ± 8.4%. In time-kill curves, a significant decrease in cell density was observed with the SICs of antimicrobials/punicalagin (0.03-60 µg/mL/30, 100, 500 µg/mL of punicalagin) combinations. CONCLUSIONS: The P. granatum peel methanol extract exhibited antimicrobial activity against MDR Enterobacteriaceae pathogens. Punicalagin, the bacteriostatic flavonoid act as a concentration-dependent sensitizing agent for antimicrobials against Enterobacteriaceae. Our findings for the therapeutic punicalagin-antimicrobial combination prompt further evaluation of punicalagin as a potent activator for drugs, which otherwise remain less or inactive against MDR strains.

Isolation of Hydrolyzable Tannins from Castanea sativa Using Centrifugal Partition Chromatography.

Castanea sativa wood is a rich source of hydrolyzable tannins, known for their diverse bioactivities. To investigate these bioactive properties further, it is crucial to isolate and characterize hydrophilic compounds effectively. To address this issue, we developed a centrifugal partition chromatography (CPC) method and applied it to an aqueous C. sativa wood extract. We determined the partition coefficients (KD) of the six major compounds using four butanol-/water-based biphasic solvent systems. Initially, we utilized the n-butanol/propanol/water (3:1:4, v/v/v) systems for the first fractionation step. Subsequently, we employed the water/methyl tert-butyl ether/butanol/acetone (8:5:3:4, v/v/v/v) system to fractionate moderately and highly hydrophilic fractions. We calculated the KD values for major compounds of the most hydrophilic fractions using the butanol/ethanol/water (4:1:5, v/v/v) and butanol/isopropanol/water (2:1:3, v/v/v) systems. In total, we isolated 23 compounds through a combination of CPC, size exclusion chromatography, and preparative HPLC. Among these compounds, six have never been previously described. We characterized them by 1D and 2D NMR experiments and high-resolution mass spectroscopy acquisitions.