ABSTRACT
Cerebral amyloid angiopathy (CAA) is a prevalent vascular dementia and common comorbidity of Alzheimer's disease (AD). While it is known that vascular fibrillar amyloid ß (Aß) deposits leads to vascular deterioration and can drive parenchymal CAA related inflammation (CAA-ri), underlying mechanisms of CAA pathology remain poorly understood. Here, we conducted brain regional proteomic analysis of early and late disease stages in the rTg-DI CAA rat model to gain molecular insight to mechanisms of CAA/CAA-ri progression and identify potential brain protein markers of CAA/CAA-ri. Longitudinal brain regional proteomic analysis revealed increased differentially expressed proteins (DEP) including ANXA3, HTRA1, APOE, CST3, and CLU, shared between the cortex, hippocampus, and thalamus, at both stages of disease in rTg-DI rats. Subsequent pathway analysis indicated pathway enrichment and predicted activation of TGF-ß1, which was confirmed by immunolabeling and ELISA. Further, we identified numerous CAA related DEPs associate with astrocytes (HSPB1 and MLC1) and microglia (ANXA3, SPARC, TGF-ß1) not previously associated with astrocytes or microglia in other AD models, possibly indicating that they are specific to CAA-ri. Thus, the data presented here identify several potential brain protein biomarkers of CAA/CAA-ri while providing novel molecular and mechanistic insight to mechanisms of CAA and CAA-ri pathological progression and glial cell mediated responses.
Subject(s)
Alzheimer Disease , Cerebral Amyloid Angiopathy , Rats , Animals , Amyloid beta-Peptides/metabolism , Transforming Growth Factor beta1/metabolism , Proteomics , Cerebral Amyloid Angiopathy/pathology , Alzheimer Disease/metabolism , Brain/metabolism , Inflammation/pathologyABSTRACT
The Per- and polyfluoroalkyl substances (PFAS) are a wide group of fluorinated compounds, which the health effects of many of them have not been investigated. Perfluorinated sulfonates, such as perfluorooctane sulfonate (PFOS) and perfluorinated carboxylates, such as perfluorooctanoic acid (PFOA) are members of this broad group of PFAS, and previous studies have shown a correlation between the body accumulation of PFOS and PFOA and increased adipogenesis. PFOA and PFOS have been withdrawn from the market and use is limited because of their persistence, toxicity, and bioaccumulative properties. Instead, short chain PFAS have been created to replace PFOA and PFOS, but the health effects of other short chain PFAS are largely unknown. Therefore, herein we aimed to comprehensively determined the potential adipogenesis of ten different PFAS (PFBS, PFHxS, PFOS, PFBA, PFHxA, PFHA, PFOA, PFNA, PFDA, and HFPO-DA) and investigated the differences in protein expression of 3T3-L1 cells upon exposure to each PFAS. 3T3-L1 cells were differentiated with or without each PFAS for 4-days, and cellular lipid was quantified using Nile Red staining. Analysis of the adipocyte proteome was performed to identify the pathways related to adipogenesis and quantify proteins significantly affected by each PFAS. The results showed that in general, every PFAS investigated in our study has the potential to induce the 3T3-L1 differentiation to adipocytes in the presence of rosiglitazone, with the concentrations that range between 0.25 and 25 µM. Proteomics analysis revealed specific markers regarding to adipogenesis upregulated upon exposure to each of the ten PFAS.
Subject(s)
Adipocytes/drug effects , Adipogenesis/drug effects , Fluorocarbons/toxicity , Lipid Metabolism/drug effects , Proteome/drug effects , 3T3-L1 Cells , Adipocytes/metabolism , Alkanesulfonic Acids , Animals , Caprylates , Mice , Protein Interaction Maps , Proteome/metabolism , Proteomics , Rosiglitazone/pharmacologyABSTRACT
Myeloid-derived suppressor cells (MDSCs) promote immunosuppressive activities in the tumor microenvironment (TME), resulting in increased tumor burden and diminishing the anti-tumor response of immunotherapies. While primary and metastatic tumors are typically the focal points of therapeutic development, the immune cells of the TME are differentially programmed by the tissue of the metastatic site. In particular, MDSCs are programmed uniquely within different organs in the context of tumor progression. Given that MDSC plasticity is shaped by the surrounding environment, the proteomes of MDSCs from different metastatic sites are hypothesized to be unique. A bottom-up proteomics approach using sequential window acquisition of all theoretical mass spectra (SWATH-MS) was used to quantify the proteome of CD11b+ cells derived from murine liver metastases (LM) and lung metastases (LuM). A comparative proteomics workflow was employed to compare MDSC proteins from LuM (LuM-MDSC) and LM (LM-MDSC) while also elucidating common signaling pathways, protein function, and possible drug-protein interactions. SWATH-MS identified 2516 proteins from 200 µg of sample. Of the 2516 proteins, 2367 have matching transcriptomic data. Upregulated proteins from lung and liver-derived murine CD11b+ cells with matching mRNA transcriptomic data were categorized based on target knowledge and level of drug development. Comparative proteomic analysis demonstrates that liver and lung tumor-derived MDSCs have distinct proteomes that may be subject to pharmacologic manipulation.
ABSTRACT
Objectives: Alzheimer's disease (AD) is a growing global health crisis exacerbated by increasing life span and an aging demographic. Convergent lines of evidence, including genome-wide association studies, strongly implicate neuroinflammation in the pathogenesis of AD. Several dietary agents, including phenolic-rich foods, show promise for the prevention and/or management of AD, which in large part, has been attributed to their anti-inflammatory effects. We previously reported that a food-grade phenolic-enriched maple syrup extract (MSX) inhibited neuroinflammation in vitro but whether these effects are translatable in vivo remain unknown. Herein, we assessed MSX's ability to attenuate early neuroinflammation in a transgenic mouse model of AD.Methods: The effects of MSX on AD-related neuroinflammation was evaluated by orally administering MSX (100 and 200 mg/kg/day for 30 days) to the 3xTg-AD mouse model of AD. The expression of inflammatory markers in mouse brains were analyzed with LC-MS/MS with SWATH acquisition.Results: 3xTg-AD mice dosed orally with MSX have decreased expression of several inflammatory proteins, including, most notably, the AD risk-associated protein 'triggering receptor expressed on myeloid cells-2' (TREM2), and stimulator of interferon genes TMEM173, and suppressor of cytokine signaling-6 (SOCS6). However, this decrease in inflammation did not coincide with a decrease in pathogenic amyloid generation or lipid peroxidation.Discussion: These data demonstrate that oral administration of this maple syrup derived natural product reduces key neuroinflammatory indices of AD in the 3xTg-AD model of AD. Therefore, further studies to investigate MSX's potential as a dietary intervention strategy for AD prevention and/or management are warranted.
Subject(s)
Acer , Alzheimer Disease , Anti-Inflammatory Agents/administration & dosage , Neuroinflammatory Diseases/drug therapy , Phenols/administration & dosage , Plant Extracts/administration & dosage , Alzheimer Disease/metabolism , Amyloid beta-Peptides/analysis , Animals , Brain Chemistry , Disease Models, Animal , Female , Mass Spectrometry , Membrane Glycoproteins/analysis , Mice , Mice, Transgenic , Neuroinflammatory Diseases/metabolism , Phytotherapy , Receptors, Immunologic/analysisABSTRACT
Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that proliferate in the setting of cancer and have potent immunosuppressive functions hindering anti-tumor immunity. Here we establish that the immunologic landscape and tumor microenvironments (TME) vary between different organs which discretely shape MDSC repertoires. We found that pSTAT3 signaling exerts a dominant effect on MDSC programming in liver metastasis (LM). In contrast, in lung metastasis (LuM), MDSC programming is driven mainly by pSTAT5. Adoptive transfer of LM-MDSC into LuM resulted in a shift from pSTAT3 signaling to pSTAT5, in association with an overall shift toward lung MDSC programming. A shift from more immunosuppressive M-MDSC to G-MDSC, along with enhanced differentiation of MDSCs into pro-inflammatory M1 macrophages in LuM, indicated that MDSC plasticity and differentiation patterns are environmentally dependent. Using mass spectroscopy, we confirmed that LM-MDSCs showed enhanced expression of key proliferation pathway markers. This confirmed that liver-specific MDSC programing was comprehensive but reversible, implying that therapeutic targeting of LM-MDSC could prime the TME in a favorable manner. Our data suggest that MDSC programming in response to malignancy is highly dependent on organ-specific conditions and is modifiable.
Subject(s)
Granulocytes/metabolism , Lung Neoplasms/metabolism , Monocytes/metabolism , Myeloid-Derived Suppressor Cells/metabolism , Tumor Microenvironment , Animals , Cell Line, Tumor , Granulocytes/pathology , Lung Neoplasms/pathology , Male , Mice , Monocytes/pathology , Myeloid-Derived Suppressor Cells/pathology , Organ SpecificityABSTRACT
Diets rich in fats are linked to elevated systemic inflammation, which augments the progression of inflammatory-related disorders including non-alcoholic fatty liver disease (NAFLD) and neurodegenerative diseases. A phenolic-enriched pomegranate fruit extract (PE) was investigated for its hepatoprotective and anti-inflammatory effects in male C57BL/6 mice fed either a high-fat diet or a standard rodent diet with or without 1% of PE for 12 weeks. Mouse livers and hippocampi were evaluated for the expression of genes associated with NAFLD and inflammation by multiplexed gene analysis. PE alleviated diet-induced fatty liver and suppressed hepatic lipid regulating genes including Cd36, Fas, Acot2 and Slc27a1. In addition, PE suppressed gene expression of pro-inflammatory cytokines including Il-1α, Il-7, Il-11, Ifnα, Tnfα and Lepr in the hippocampi. Our findings support the protective effects of PE against high-fat diet-induced hepatic and neurological disease.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Diet, High-Fat/adverse effects , Fruit/chemistry , Liver/drug effects , Obesity/drug therapy , Plant Extracts/pharmacology , Pomegranate/chemistry , Adipose Tissue/metabolism , Alzheimer Disease , Animals , Cytokines/metabolism , Fatty Liver/drug therapy , Gene Expression , Inflammation , Lipid Metabolism/drug effects , Lipids , Liver/metabolism , Liver/pathology , Male , Mice , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/drug therapy , Obesity/chemically induced , Phenols/pharmacologyABSTRACT
Black cumin (Nigella sativa) seed extract has been shown to improve dermatological conditions, yet its beneficial effects for skin are not fully elucidated. Herein, Thymocid®, a chemically standardized black cumin seed extract, was investigated for its cosmeceutical potential including anti-aging properties associated with modulation of glycation, collagen cross-linking, and collagenase and elastase activities, as well as antimelanogenic effect in murine melanoma B16F10 cells. Thymocid® (50, 100, and 300 µg/mL) inhibited the formation of advanced glycation end-products (by 16.7-70.7%), collagen cross-linking (by 45.1-93.3%), collagenase activity (by 10.4-92.4%), and elastases activities (type I and III by 25.3-75.4% and 36.0-91.1%, respectively). In addition, Thymocid® (2.5-20 µg/mL) decreased melanin content in B16F10 cells by 42.5-61.6% and reduced cellular tyrosinase activity by 20.9% (at 20 µg/mL). Furthermore, Thymocid® (20 µg/mL for 72 h) markedly suppressed the mRNA expression levels of melanogenesis-related genes including microphthalmia-associated transcription factor (MITF), tyrosinase-related protein 1 (TYRP1), and TYRP2 to 78.9%, 0.3%, and 0.2%, respectively. Thymocid® (10 µg/mL) also suppressed the protein expression levels of MITF (by 15.2%) and TYRP1 (by 97.7%). Findings from this study support the anti-aging and antimelanogenic potential of Thymocid® as a bioactive cosmeceutical ingredient for skin care products.
Subject(s)
Collagen/metabolism , Collagenases/metabolism , Intramolecular Oxidoreductases/metabolism , Melanins/metabolism , Melanoma, Experimental/metabolism , Melanoma, Experimental/prevention & control , Membrane Glycoproteins/metabolism , Microphthalmia-Associated Transcription Factor/metabolism , Nigella sativa/chemistry , Oxidoreductases/metabolism , Pancreatic Elastase/metabolism , Phytotherapy , Plant Extracts/pharmacology , Seeds/chemistry , Animals , Cell Line, Tumor , Cosmetics , Glycation End Products, Advanced/metabolism , Mice , Plant Extracts/therapeutic use , Skin CareABSTRACT
Increasing evidence supports the beneficial effects of polyphenol-rich diets, including the traditional Mediterranean diet, for the management of cardiovascular disease, obesity and neurodegenerative diseases. However, a common concern when discussing the protective effects of polyphenol-rich diets against diseases is whether these compounds are present in systemic circulation in their intact/parent forms in order to exert their beneficial effects in vivo. Here, we explore two common classes of dietary polyphenols, namely isoflavones and lignans, and their gut microbial-derived metabolites for gut and blood-brain barrier predicted permeability, as well as protection against neuroinflammatory stimuli in murine BV-2 microglia. Polyphenol microbial metabolites (PMMs) generally showed greater permeability through artificial gut and blood-brain barriers compared to their parent compounds. The parent polyphenols and their corresponding PMMs were evaluated for protective effects against lipopolysaccharide-induced inflammation in BV-2 microglia. The lignan-derived PMMs, equol and enterolactone, exhibited protective effects against nitric oxide production, as well as against pro-inflammatory cytokines (IL-6 and TNF-α) in BV-2 microglia. Therefore, PMMs may contribute, in large part, to the beneficial effects attributed to polyphenol-rich diets, further supporting the important role of gut microbiota in human health and disease prevention.
ABSTRACT
OBJECTIVES: Urolithins, ellagitannin-gut microbial-derived metabolites, have been reported to mediate pomegranate's neuroprotective effects against Alzheimer's disease (AD), but there are limited data on their effects against neuroinflammation. Herein, we: (1) evaluated whether urolithins (urolithins A and B and their methylated derivatives) attenuate neuroinflammation in murine BV-2 microglia and human SH-SY5Y neurons, and (2) evaluated hippocampus of transgenic AD (R1.40) mice administered a pomegranate extract (PE; 100 or 200â mg/kg/day for 3 weeks) for inflammatory biomarkers. METHODS: Effects of urolithins (10â µM) on inflammatory biomarkers were evaluated in lipopolysaccharide (LPS)-stimulated BV-2 microglia. In a non-contact co-culture cell model, SH-SY5Y cell viability was assessed after exposure to media collected from LPS-BV-2 cells treated with or without urolithins. Effects of urolithins on apoptosis and caspase 3/7 and 9 release from H2O2-induced oxidative stress of BV-2 and SH-SY5Y cells were assessed. Hippocampal tissues of vehicle and PE-treated transgenic R1.40 mice were evaluated for gene expression of inflammatory biomarkers by qRT-PCR. RESULTS: Urolithins decreased media levels of nitric oxide, interleukin 6 (IL-6), prostaglandin E2, and tumor necrosis factor alpha from LPS-BV-2 microglia. In the co-culture cell model, media from LPS-BV-2 cells treated with urolithins preserved SH-SY5Y cell viability greater than media from cells treated without urolithins. Urolithins mitigated apoptosis and caspase 3/7 and 9 release from H2O2-induced oxidative stress of BV-2 and SH-SY5Y cells. While not statistically significant, inflammatory biomarkers (TNF-α, COX-2, IL-1, and IL-6) appeared to follow a decreasing trend in the hippocampus of high-dose PE-treated animals compared to controls. DISCUSSION: The attenuation of neuroinflammation by urolithins may contribute, in part, toward pomegranate's neuroprotective effects against AD.
Subject(s)
Coumarins/administration & dosage , Encephalitis/metabolism , Gastrointestinal Microbiome , Hydrolyzable Tannins/metabolism , Lythraceae/metabolism , Neuroprotective Agents/administration & dosage , Animals , Apoptosis/drug effects , Cell Line , Cell Line, Tumor , Encephalitis/chemically induced , Encephalitis/prevention & control , Hippocampus/drug effects , Hippocampus/metabolism , Humans , Inflammation Mediators , Lipopolysaccharides/administration & dosage , Mice, Transgenic , Microglia/drug effects , Microglia/metabolism , Neurons/drug effects , Neurons/metabolism , Oxidative Stress/drug effects , Plant Extracts/administration & dosageABSTRACT
Pomegranate phenolics have been reported to exert skin beneficial effects but their mechanisms of action remain unclear. Herein, we investigated a standardized commercial pomegranate extract (PE; Pomella®) and its phenolics including punicalagin (PA), ellagic acid (EA), and urolithin A (UA) for their protective effects against hydrogen peroxide (H2O2)-induced oxidative stress and cytotoxicity in human keratinocyte HaCaT cells. PE, PA, and EA reduced the production of H2O2-induced ROS in HaCaT cells by 1.03-, 1.37-, and 2.67-fold, respectively. PE, PA, and UA increased the viability of H2O2-stimulated HaCaT cells by 89.9, 94.9, and 90.0%, respectively. PE, PA, and UA reduced apoptotic cell populations by 3.39, 7.11, and 8.26%, respectively. In addition, PE, PA and UA decreased H2O2-stimulated caspase-3 level by 2.31-, 2.06-, and 2.68-fold, respectively. The ameliorative effects of this PE and its phenolics against the H2O2-induced oxidative stress and cytotoxicity in keratinocytes support their utilization as natural cosmeceuticals for skin health..
ABSTRACT
Mucuna pruriens (Mucuna) has been prescribed in Ayurveda for various brain ailments including 'kampavata' (tremors) or Parkinson's disease (PD). While Mucuna is a well-known natural source of levodopa (L-dopa), published studies suggest that other bioactive compounds may also be responsible for its anti-PD effects. To investigate this hypothesis, an L-dopa reduced (<0.1%) M. pruriens seeds extract (MPE) was prepared and evaluated for its anti-PD effects in cellular (murine BV-2 microglia and human SH-SY5Y neuroblastoma cells), Caenorhabditis elegans, and Drosophila melanogaster models. In BV-2 cells, MPE (12.5â»50 µg/mL) reduced hydrogen peroxide-induced cytotoxicity (15.7-18.6%), decreased reactive oxygen species production (29.1-61.6%), and lowered lipopolysaccharide (LPS)-induced nitric oxide species release by 8.9â»60%. MPE (12.5-50 µg/mL) mitigated SH-SY5Y cell apoptosis by 6.9-40.0% in a non-contact co-culture assay with cell-free supernatants from LPS-treated BV-2 cells. MPE (12.5-50 µg/mL) reduced 6-hydroxydopamine (6-OHDA)-induced cell death of SH-SY5Y cells by 11.85â»38.5%. Furthermore, MPE (12.5-50 µg/mL) increased median (25%) and maximum survival (47.8%) of C. elegans exposed to the dopaminergic neurotoxin, methyl-4-phenylpyridinium. MPE (40 µg/mL) ameliorated dopaminergic neurotoxin (6-OHDA and rotenone) induced precipitation of innate negative geotaxis behavior of D. melanogaster by 35.3 and 32.8%, respectively. Therefore, MPE contains bioactive compounds, beyond L-dopa, which may impart neuroprotective effects against PD.
Subject(s)
Levodopa/pharmacology , Microglia/drug effects , Mucuna/chemistry , Neuroprotective Agents/pharmacology , Plant Extracts/pharmacology , 1-Methyl-4-phenylpyridinium/toxicity , Animals , Caenorhabditis elegans/drug effects , Caenorhabditis elegans/metabolism , Cell Line, Tumor , Disease Models, Animal , Dopamine Agents/toxicity , Drosophila melanogaster/drug effects , Drosophila melanogaster/metabolism , Humans , Male , Microglia/metabolism , Neuroblastoma/metabolism , Oxidopamine/toxicity , Parkinson Disease/drug therapy , Reactive Oxygen Species/metabolism , Seeds/chemistryABSTRACT
Glycation is associated with several neurodegenerative disorders, including Alzheimer's disease (AD), where it potentiates the aggregation and toxicity of proteins such as ß-amyloid (Aß). Published studies support the anti-glycation and neuroprotective effects of several polyphenol-rich fruits, including berries, which are rich in anthocyanins. Herein, blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts were evaluated for: (1) total phenolic and anthocyanins contents, (2) free radical (DPPH) scavenging and reactive carbonyl species (methylglyoxal; MGO) trapping, (3) anti-glycation (using BSA-fructose and BSA-MGO models), (4) anti-Aß aggregation (using thermal- and MGO-induced fibrillation models), and, (5) murine microglia (BV-2) neuroprotective properties. Berry crude extracts (CE) were fractionated to yield anthocyanins-free (ACF) and anthocyanins-enriched (ACE) extracts. The berry ACEs (at 100 µg/mL) showed superior free radical scavenging, reactive carbonyl species trapping, and anti-glycation effects compared to their respective ACFs. The berry ACEs (at 100 µg/mL) inhibited both thermal- and MGO-induced Aß fibrillation. In addition, the berry ACEs (at 20 µg/mL) reduced H2O2-induced reactive oxygen species production, and lipopolysaccharide-induced nitric oxide species in BV-2 microglia as well as decreased H2O2-induced cytotoxicity and caspase-3/7 activity in BV-2 microglia. The free radical scavenging, reactive carbonyl trapping, anti-glycation, anti-Aß fibrillation, and microglial neuroprotective effects of these berry extracts warrant further in vivo studies to evaluate their potential neuroprotective effects against AD.
Subject(s)
Amyloid beta-Peptides/antagonists & inhibitors , Anthocyanins/pharmacology , Antioxidants/pharmacology , Fruit/chemistry , Neuroprotective Agents/pharmacology , Polyphenols/pharmacology , Amyloid beta-Peptides/genetics , Amyloid beta-Peptides/metabolism , Animals , Anthocyanins/isolation & purification , Antioxidants/isolation & purification , Biphenyl Compounds/antagonists & inhibitors , Blueberry Plants/chemistry , Caspases/genetics , Caspases/metabolism , Cell Line , Fragaria/chemistry , Gene Expression Regulation , Glycosylation/drug effects , Hydrogen Peroxide/antagonists & inhibitors , Hydrogen Peroxide/pharmacology , Mice , Neuroglia/cytology , Neuroglia/drug effects , Neuroglia/physiology , Neuroprotective Agents/isolation & purification , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/biosynthesis , Picrates/antagonists & inhibitors , Plant Extracts/chemistry , Polyphenols/isolation & purification , Protein Aggregates/drug effects , Pyruvaldehyde/antagonists & inhibitors , Pyruvaldehyde/pharmacology , Rubus/chemistry , Vaccinium macrocarpon/chemistryABSTRACT
Maple sap, collected from the sugar maple (Acer saccharum) tree, is boiled to produce the popular plant-derived sweetener, maple syrup, which can then be further evaporated to yield a traditional North American confectionery, maple sugar. Although maple sap and maple syrup have been previously studied, the phytochemical constituents of maple sugar are unknown. Herein, 30 phenolic compounds, 1-30, primarily lignans, were isolated and identified (by HRESIMS and NMR) from maple sugar. The isolates included the phenylpropanoid-based lignan tetramers (erythro,erythro)-4â³,4â´-dihydroxy-3,3',3â³,3â´,5,5'-hexamethoxy-7,9';7',9-diepoxy-4,8â³;4',8â´-bisoxy-8,8'-dineolignan-7â³,7â´,9â³,9â´-tetraol, 29, and (threo,erythro)-4â³,4â´-dihydroxy-3,3',3â³,3â´,5,5'-hexamethoxy-7,9';7',9-diepoxy-4,8â³;4',8â´-bisoxy-8,8'-dineolignan-7â³,7â´,9â³,9â´-tetraol, 30, neither of which have been identified from maple sap or maple syrup before. Twenty of the isolates (selected on the basis of sample quantity available) were evaluated for their potential biological effects against lipopolysaccharide-induced inflammation in BV-2 microglia in vitro and juglone-induced oxidative stress in Caenorhabditis elegans in vivo. The current study increases scientific knowledge of possible bioactive compounds present in maple-derived foods including maple sugar.
Subject(s)
Acer/chemistry , Phenols/chemistry , Phenols/pharmacology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Sweetening Agents/chemistry , Sweetening Agents/pharmacology , Animals , Caenorhabditis elegans/drug effects , Caenorhabditis elegans/metabolism , Microglia/drug effects , Microglia/immunology , Molecular Structure , Oxidative Stress/drug effects , Phenols/isolation & purification , Plant Extracts/isolation & purification , Sweetening Agents/isolation & purification , United StatesABSTRACT
The red maple (Acer rubrum) is a rich source of phenolic compounds which possess galloyl groups attached to different positions of a 1,5-anhydro-D-glucitol core. While these glucitol-core containing gallotannins (GCGs) have reported anti-oxidant and anti-glycative effects, they have not yet been evaluated for their cosmetic applications. Herein, the anti-tyrosinase and anti-melanogenic effects of a proprietary phenolic-enriched red maple leaves extract [Maplifa™; contains ca. 45% ginnalin A (GA) along with other GCGs] were investigated using enzyme and cellular assays. The GCGs showed anti-tyrosinase activity with IC50 values ranging from 101.4 to 1047.3 µM and their mechanism of tyrosinase inhibition (using GA as a representative GCG) was evaluated by chelating and computational/modeling studies. GA reduced melanin content in murine melanoma B16F10 cells by 79.1 and 56.7% (at non-toxic concentrations of 25 and 50 µM, respectively), and its mechanisms of anti-melanogenic effects were evaluated by using methods including fluorescent probe (DCF-DA), real-time PCR, and western blot experiments. These data indicated that GA was able to: (1) reduce the levels of reactive oxygen species, (2) down-regulate the expression of MITF, TYR, TRP-1, and TRP-2 gene levels in a time-dependent manner, and (3) significantly reduce protein expression of the TRP-2 gene. Therefore, the anti-melanogenic effects of red maple GCGs warrant further investigation of this proprietary natural product extract for potential cosmetic applications.
Subject(s)
Acer/immunology , Hydrolyzable Tannins/therapeutic use , Intramolecular Oxidoreductases/metabolism , Melanocytes/drug effects , Plant Extracts/therapeutic use , Skin Neoplasms/drug therapy , Sorbitol/therapeutic use , Animals , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hydrolyzable Tannins/chemistry , Intramolecular Oxidoreductases/genetics , Melanins/metabolism , Melanocytes/physiology , Melanoma, Experimental , Mice , Phenols/chemistry , Plant Extracts/chemistry , Plant Leaves , Sorbitol/chemistryABSTRACT
Oxidative stress and free radical generation accelerate the formation of advanced glycation endproducts (AGEs) which are linked to several chronic diseases. Published data suggest that phenolic-rich plant foods, show promise as natural anti-AGEs agents due to their anti-oxidation capacities. A phenolic-enriched maple syrup extract (MSX) has previously been reported to show anti-inflammatory and neuroprotective effects but its anti-AGE effects remain unknown. Therefore, herein, we investigated the anti-glycation and anti-oxidation effects of MSX using biochemical and biophysical methods. MSX (500 µg mL-1) reduced the formation of AGEs by 40% in the bovine serum albumin (BSA)-fructose assay and by 30% in the BSA-methylglyoxal (MGO) assay. MSX also inhibited the formation of crosslinks typically seen in the late stage of glycation. Circular dichroism and differential scanning calorimeter analyses demonstrated that MSX maintained the structure of BSA during glycation. In the anti-oxidant assays, MSX (61.7 µg mL-1) scavenged 50% of free radicals (DPPH assay) and reduced free radical generation by 20% during the glycation process (electron paramagnetic resonance time scan). In addition, the intracellular levels of hydrogen peroxide induced reactive oxygen species were reduced by 27-58% with MSX (50-200 µg mL-1) in normal/non-tumorigenic human colon CCD-18Co cells. Moreover, in AGEs and MGO challenged CCD-18Co cells, higher cellular viabilities and rapid extracellular signal-regulated kinase (ERK) phosphorylation were observed in MSX treated cells, indicating its protective effects against AGEs-induced cytotoxicity. Overall, this study supports the biological effects of MSX, and warrants further investigation of its potential as a dietary agent against diseases mediated by oxidative stress and inflammation.
Subject(s)
Acer/chemistry , Antioxidants/pharmacology , Colon/drug effects , Oxidative Stress/drug effects , Phenols/pharmacology , Plant Extracts/pharmacology , Cell Line , Cell Proliferation/drug effects , Colon/cytology , Colon/metabolism , Glycation End Products, Advanced/metabolism , Glycosylation/drug effects , Humans , Phenols/analysis , Reactive Oxygen Species/metabolismABSTRACT
In the course of our group's investigation of members of the maple (Acer) genus, a series of glucitol-core containing gallotannins (GCGs) were-isolated and identified (by NMR and HREISMS). Among higher plants, only certain maple species are known to produce GCGs, compounds with potential nutraceutical and cosmetic applications due to their reported antioxidant, antidiabetic, anti-α-glucosidase, anti-glycation, anticancer, and skin. health promoting effects. Herein, we sought to investigate whether the previously un-investigated silver maple (Acer saccharinum) species was also a source of GCGs. Nine phenolic compounds, including six GCGs, were identified (by HPLC-DAD analyses using previously isolated standards) as ginnalins A-C (1-3), rnaplexins B, D, and F (4-6), methyl syringate (7), methyl gallate (8), and 3-methoxy-4-hydroxyphenol-1-ß-D-(6-galloyl)-glucopyranoside (9). In addition, one, sesquiterpenoid, namely, pubineroid A (10), was isolated and identified (by NMR).
Subject(s)
Acer/chemistry , Hydrolyzable Tannins/chemistry , Hydrolyzable Tannins/pharmacology , Plant Leaves/chemistry , Sorbitol/chemistry , Chromatography, High Pressure Liquid , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Extracts/chemistry , Spectrometry, Mass, Electrospray IonizationABSTRACT
Medicinal plants are promising candidates for Alzheimer's disease (AD) research but there is lack of systematic algorithms and procedures to guide their selection and evaluation. Herein, we developed a Neuroprotective Potential Algorithm (NPA) by evaluating twenty-three standardized and chemically characterized Ayurvedic medicinal plant extracts in a panel of bioassays targeting oxidative stress, carbonyl stress, protein glycation, amyloid beta (Aß) fibrillation, acetylcholinesterase (AChE) inhibition, and neuroinflammation. The twenty-three herbal extracts were initially evaluated for: 1) total polyphenol content (Folin-Ciocalteu assay), 2) free radical scavenging capacity (DPPH assay), 3) ferric reducing antioxidant power (FRAP assay), 4) reactive carbonyl species scavenging capacity (methylglyoxal trapping assay), 5) anti-glycative effects (BSA-fructose, and BSA-methylglyoxal assays) and, 6) anti-Aß fibrillation effects (thioflavin-T assay). Based on assigned index scores from the initial screening, twelve extracts with a cumulative NPA score ≥40 were selected for further evaluation for their: 1) inhibitory effects on AChE activity, 2) in vitro anti-inflammatory effects on murine BV-2 microglial cells (Griess assay measuring levels of lipopolysaccharide-induced nitric oxide species), and 3) in vivo neuroprotective effects on Caenorhabditis elegans post induction of Aß1-42 induced neurotoxicity and paralysis. Among these, four extracts had a cumulative NPA score ≥60 including Phyllanthus emblica (amla; Indian gooseberry), Mucuna pruriens (velvet bean), Punica granatum (pomegranate) and Curcuma longa (turmeric; curcumin). These extracts also showed protective effects on H2O2 induced cytotoxicity in differentiated cholinergic human neuronal SH-SY5Y and murine BV-2 microglial cells and reduced tau protein levels in the SH-SY5Y neuronal cells. While published animal data support the neuroprotective effects of several of these Ayurvedic medicinal plant extracts, some remain unexplored for their anti-AD potential. Therefore, the NPA may be utilized, in part, as a strategy to help guide the selection of promising medicinal plant candidates for future AD-based research using animal models.
Subject(s)
Antioxidants/pharmacology , Microglia/drug effects , Oxidative Stress/drug effects , Plants, Medicinal , Algorithms , Amyloid beta-Peptides/pharmacology , Animals , Hydrogen Peroxide/pharmacology , Neuroprotective Agents/pharmacology , Neurotoxicity Syndromes/drug therapy , Plants, Medicinal/metabolismABSTRACT
Published data supports the neuroprotective effects of several phenolic-containing natural products, including certain fruit, berries, spices, nuts, green tea, and olive oil. However, limited data are available for phenolic-containing plant-derived natural sweeteners including maple syrup. Herein, we investigated the neuroprotective effects of a chemically standardized phenolic-enriched maple syrup extract (MSX) using a combination of biophysical, in vitro, and in vivo studies. Based on biophysical data (Thioflavin T assay, transmission electron microscopy, circular dichroism, dynamic light scattering, and zeta potential), MSX reduced amyloid ß1-42 peptide (Aß1-42) fibrillation in a concentration-dependent manner (50-500 µg/mL) with similar effects as the neuroprotective polyphenol, resveratrol, at its highest test concentration (63.5 % at 500 µg/mL vs. 77.3 % at 50 µg/mL, respectively). MSX (100 µg/mL) decreased H2O2-induced oxidative stress (16.1 % decrease in ROS levels compared to control), and down-regulated the production of lipopolysaccharide (LPS)-stimulated inflammatory markers (22.1, 19.9, 74.8, and 87.6 % decrease in NOS, IL-6, PGE2, and TNFα levels, respectively, compared to control) in murine BV-2 microglial cells. Moreover, in a non-contact co-culture cell model, differentiated human SH-SY5Y neuronal cells were exposed to conditioned media from BV-2 cells treated with MSX (100 µg/mL) and LPS or LPS alone. MSX-BV-2 media increased SH-SY5Y cell viability by 13.8 % compared to media collected from LPS-BV-2 treated cells. Also, MSX (10 µg/mL) showed protective effects against Aß1-42 induced neurotoxicity and paralysis in Caenorhabditis elegans in vivo. These data support the potential neuroprotective effects of MSX warranting further studies on this natural product.