Licochalcone D ameliorates lipid metabolism in hepatocytes by modulating lipogenesis and autophagy.

Metabolic dysfunction-associated fatty liver disease is a metabolic disease caused by abnormal lipid accumulation in the liver. Excessive lipid accumulation results in liver inflammation and fibrosis. Previous studies have demonstrated that the chalcone licochalcone D, which is isolated from Glycyrrhiza inflata Batal, has anti-tumor and anti-inflammatory effects. The present study explored whether licochalcone D can regulate lipid accumulation in fatty liver cells. FL83B hepatocytes were incubated with oleic acid to establish a fatty liver cell model, and then treated with licochalcone D to evaluate the molecular mechanisms underlying the regulation of lipid metabolism. In addition, male C57BL/6 mice were fed a methionine/choline-deficient diet to induce an animal model of metabolic dysfunction-associated steatohepatitis (MASH) and given 5 mg/kg licochalcone D by intraperitoneal injection. In cell experiments, licochalcone D significantly reduced lipid accumulation in fatty liver cells and reduced sterol regulatory element-binding protein 1c expression, blocking fatty acid synthase production. Licochalcone D increased adipose triglyceride lipase and carnitine palmitoyltransferase 1 expression, enhancing lipolysis and fatty acid ß-oxidation, respectively. Licochalcone D also significantly increased SIRT-1 and AMPK phosphorylation, reducing acetyl-CoA carboxylase phosphorylation and inhibiting fatty acid synthesis. Licochalcone D also increased the fusion of autophagosomes and lysosomes to promote autophagy, reducing oil droplet accumulation in fatty liver cells. In the animal experiments, licochalcone D effectively reduced the number of lipid vacuoles and degree of fibrosis in liver tissue and inhibited liver inflammation. Thus, licochalcone D can improve MASH by reducing lipid accumulation, inhibiting inflammation, and increasing autophagy.

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.

Protective effects of myricetin on airway inflammation and oxidative stress in ovalbumin-induced asthma mice.

Myricetin, a flavonoid isolated from many edible vegetables and fruits, has multiple biological effects, including anti-inflammatory and anti-tumor effects. Myricetin could inhibit mast cell degranulation in vitro, and it reduced the eosinophil content in bronchoalveolar lavage fluid (BALF) of ovalbumin (OVA)-sensitized mice. However, it remains unclear whether myricetin alleviates airway hyperresponsiveness (AHR), airway inflammation, and oxidative stress in asthma. Here, we investigated whether myricetin attenuated AHR, airway inflammation, and eosinophil infiltration in lungs of asthmatic mice. Mice were sensitized with OVA, then injected intraperitoneally with myricetin to investigate anti-inflammatory and antioxidant effects of myricetin. Moreover, we examined its effects on human bronchial epithelial BEAS-2B cells stimulated with TNF-α and IL-4, in vitro. Myricetin effectively mitigated eosinophil infiltration, AHR, and goblet cell hyperplasia in lung, and it reduced Th2 cytokine expression in BALF from asthmatic mice. Myricetin effectively promoted glutathione and superoxide dismutase productions and mitigated malondialdehyde expressions in mice by promoting Nrf2/HO-1 expression. Myricetin also reduced the production of proinflammatory cytokines, eotaxins, and reactive oxygen species in BEAS-2B cells. Myricetin effectively suppressed ICAM-1 expression in inflammatory BEAS-2B cells, which suppressed monocyte cell adherence. These results suggested that myricetin could effectively improve asthma symptoms, mainly through blocking Th2-cell activation, which reduced oxidative stress, AHR, and airway inflammation.

Mulberroside F improves airway hyperresponsiveness and inflammation in asthmatic mice.

Mulberroside F is isolated from the leaves and roots of Morus alba L. Here, we investigated whether mulberroside F could alleviate airway inflammation and eosinophil infiltration in the lungs of asthmatic mice. We also examined whether mulberroside F attenuated inflammatory responses in human tracheal epithelial BEAS-2B cells. Female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and administered different doses of mulberroside F via intraperitoneal injection. Additionally, tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells were treated with various doses of mulberroside F, followed by detection of the expressions of inflammatory cytokines and chemokines. The results demonstrated that mulberroside F mitigated the levels of proinflammatory cytokines and chemokines, and CCL11, in inflammatory BEAS-2B cells. Mulberroside F also suppressed reactive oxygen species (ROS) production and ICAM-1 expression in TNF-α-stimulated BEAS-2B cells, which effectively suppressed monocyte cell adherence. In an animal model of asthma, mulberroside F treatment attenuated airway hyperresponsiveness, eosinophil infiltration, and goblet cell hyperplasia. Mulberroside F treatment also decreased lung fibrosis and airway inflammation in OVA-sensitized mice. Moreover, mulberroside F significantly reduced expressions of Th2-associated cytokines (including interleukin(IL)-4, IL-5, and IL-13) in bronchoalveolar lavage fluid compared to OVA-sensitized mice. Our results confirmed that mulberroside F is a novel bioactive compound that can effectively reduce airway inflammation and eosinophil infiltration in asthmatic mice via inhibition of Th2-cell activation.

Oleuropein attenuates inflammation and regulates immune responses in a 2,4-dinitrochlorobenzene-induced atopic dermatitis mouse model.

BACKGROUND: Olive (Olea europaea Linn) leaves contain a phenolic compound oleuropein (Ole) has antioxidant, anti-inflammatory, and immunomodulatory activities. However, whether Ole might be an effective treatment for atopic dermatitis (AD) remains unknown. OBJECTIVE: This study investigated the functional role of oleuropein in a 2,4-dinitrochlorobenzene-induced AD-like mouse model, with a focus on allergic inflammation. METHODS: We evaluated cytokine gene expression, COX-2 inflammatory protein production, and Th2 related cytokine regulation of mast cells and eosinophils that infiltrated AD-like skin lesions. RESULTS: A topical application of Ole significantly reduced Th2-related cytokine gene expression (IL-4 and IL-5) and inflammatory COX-2 protein production in AD-like skin lesions. Additionally, Ole suppressed serum IgE levels. Furthermore, Ole effectively reduced ear swelling and epidermal and dermal thickening. CONCLUSIONS: These results suggested that, mechanistically, Ole treatment improved allergic inflammation by blocking the Th2-driven inflammatory axis. In conclusion, our findings indicated that Ole showed promise in treating AD by regulating serum IgE and Th2 cytokine levels. Although the effects of Ole on AD in humans require clinical trials, our results provided insights into how AD treatments might be improved.

Gypenoside A from Gynostemma pentaphyllum Attenuates Airway Inflammation and Th2 Cell Activities in a Murine Asthma Model.

Our previous study found that oral administration of Gynostemma pentaphyllum extract can attenuate airway hyperresponsiveness (AHR) and reduce eosinophil infiltration in the lungs of asthmatic mice. Gypenoside A is isolated from G. pentaphyllum. In this study, we investigated whether gypenoside A can effectively reduce asthma in mice. Asthma was induced in BALB/c mice by ovalbumin injection. Asthmatic mice were treated with gypenoside A via intraperitoneal injection to assess airway inflammation, AHR, and immunomodulatory effects. In vitro, gypenoside A reduced inflammatory and oxidative responses in inflammatory tracheal epithelial cells. Experimental results showed that gypenoside A treatment can suppress eosinophil infiltration in the lungs, reduce tracheal goblet cell hyperplasia, and attenuate AHR. Gypenoside A significantly reduced Th2 cytokine expression and also inhibited the expression of inflammatory genes and proteins in the lung and bronchoalveolar lavage fluid. In addition, gypenoside A also significantly inhibited the secretion of inflammatory cytokines and chemokines and reduced oxidative expression in inflammatory tracheal epithelial cells. The experimental results suggested that gypenoside A is a natural compound that can effectively reduce airway inflammation and AHR in asthma, mainly by reducing Th2 cell activation.

Acacetin Protects against Non-Alcoholic Fatty Liver Disease by Regulating Lipid Accumulation and Inflammation in Mice.

We previously demonstrated that acacetin reduces adipogenesis in adipocytes, and decreases lipid accumulation in visceral adipocyte tissue. Here we investigated whether acacetin regulated the mechanisms of lipogenesis and inflammation in non-alcoholic fatty liver disease (NAFLD) in obese mice. Male C57BL/6 mice were fed a high-fat diet (HFD), and then administered acacetin by intraperitoneal injection. Acacetin reduced body weight and liver weight in obese mice. Acacetin-treated obese mice exhibited decreased lipid accumulation, increased glycogen accumulation, and improved hepatocyte steatosis. Acacetin regulated triglycerides and total cholesterol in the liver and serum. Acacetin decreased low-density lipoprotein and leptin concentrations, but increased high-density lipoprotein and adiponectin levels in obese mice. Acacetin effectively weakened the gene expressions of transcription factors related to lipogenesis, and promoted the expressions of genes related to lipolysis and fatty acid ß-oxidation in liver. Acacetin also reduced expressions of inflammation-related cytokines in the serum and liver. Oleic acid induced lipid accumulation in murine FL83B hepatocytes, and the effects of acacetin treatment indicated that acacetin may regulate lipid metabolism through the AMPK pathway. Acacetin may protect against hepatic steatosis by modulating inflammation and AMPK expression.

Urolithin A Inactivation of TLR3/TRIF Signaling to Block the NF-κB/STAT1 Axis Reduces Inflammation and Enhances Antioxidant Defense in Poly(I:C)-Induced RAW264.7 Cells.

Urolithin A is an active compound of gut-microbiota-derived metabolites of polyphenol ellagic acid that has anti-aging, antioxidative, and anti-inflammatory effects. However, the effects of urolithin A on polyinosinic acid-polycytidylic acid (poly(I:C))-induced inflammation remain unclear. Poly(I:C) is a double-stranded RNA (dsRNA) similar to a virus and is recognized by Toll-like receptor-3 (TLR3), inducing an inflammatory response in immune cells, such as macrophages. Inflammation is a natural defense process of the innate immune system. Therefore, we used poly(I:C)-induced RAW264.7 cells and attenuated the inflammation induced by urolithin A. First, our data suggested that 1-30 µM urolithin A does not reduce RAW264.7 cell viability, whereas 1 µM urolithin A is sufficient for antioxidation and the decreased production of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and C-C chemokine ligand 5. The inflammation-related proteins cyclooxygenase-2 and inducible nitric oxide synthase were also downregulated by urolithin A. Next, 1 µM urolithin A inhibited the levels of interferon (INF)-α and INF-ß. Urolithin A was applied to investigate the blockade of the TLR3 signaling pathway in poly(I:C)-induced RAW264.7 cells. Moreover, the TLR3 signaling pathway, subsequent inflammatory-related pathways, and antioxidation pathways showed changes in nuclear factor-κB (NF-κB) signaling and blocked ERK/mitogen-activated protein kinase (MAPK) signaling. Urolithin A enhanced catalase (CAT) and superoxide dismutase (SOD) activities, but decreased malondialdehyde (MDA) levels in poly(I:C)-induced RAW264.7 cells. Thus, our results suggest that urolithin A inhibits TLR3-activated inflammatory and oxidative-associated pathways in macrophages, and that this inhibition is induced by poly(I:C). Therefore, urolithin A may have antiviral effects and could be used to treat viral-infection-related diseases.

Fisetin Suppresses the Inflammatory Response and Oxidative Stress in Bronchial Epithelial Cells.

Fisetin is isolated from many fruits and vegetables and has been confirmed to improve airway hyperresponsiveness in asthmatic mice. However, whether fisetin reduces inflammatory response and oxidative stress in bronchial epithelial cells is unclear. Here, BEAS-2B human bronchial epithelial cells were treated with various concentrations of fisetin and then stimulated with tumor necrosis factor-α (TNF-α) or TNF-α/interleukin-4. In addition, ovalbumin-sensitized mice were treated with fisetin to detect inflammatory mediators and oxidative stress expression. Fisetin significantly reduced the levels of inflammatory cytokines and chemokines in TNF-α-stimulated BEAS-2B cells. Fisetin also attenuated intercellular adhesion molecule-1 expression in TNF-α-stimulated BEAS-2B cells, suppressing THP-1 monocyte adhesion. Furthermore, fisetin significantly suppressed airway hyperresponsiveness in the lungs and decreased eosinophil numbers in the bronchoalveolar lavage fluid of asthmatic mice. Fisetin decreased cyclooxygenase-2 expression, promoted glutathione levels, and decreased malondialdehyde levels in the lungs of asthmatic mice. Our findings indicate that fisetin is a potential immunomodulator that can improve the pathological features of asthma by decreasing oxidative stress and inflammation.

Oleuropein Protects Human Retinal Pigment Epithelium Cells from IL-1ß-Induced Inflammation by Blocking MAPK/NF-κB Signaling Pathways.

Proinflammatory mediators such as interleukin (IL)-1ß cause retinal pigment epithelium (RPE) inflammation, which is related to visual deterioration, including age-related macular degeneration and diabetic retinopathy. Oleuropein is a polyphenol compound that shows potent anti-inflammatory, antioxidant, and anti-cancer activities, but its effects on IL-1ß-induced inflammation have not been examined in the adult RPE cell line ARPE-19. Here, we assessed the ability of oleuropein to attenuate this inflammation in ARPE-19 cells. IL-1ß induced secretion of the inflammatory cytokines IL-6, monocyte chemoattractant protein-1 (MCP)-1, and soluble intercellular adhesion molecule (sICAM)-1. As measured by enzyme-linked immunosorbent assay, oleuropein significantly inhibited levels of all three proteins and led to decreased monocyte adhesiveness to ARPE-19 cells. To clarify the underlying anti-inflammatory mechanisms, we used western blots to evaluate the effect of oleuropein on inactivation of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. The results showed that oleuropein significantly decreased levels of the inflammatory mediator cyclooxygenase-2 and increased anti-inflammatory protein HO-1 expression. We next examined if the anti-inflammatory activity of oleuropein arises via inactivated NF-κB. We found that suppressing phosphorylation of the JNK1/2 and p38 MAPK signaling pathways inhibited IL-6, MCP-1, and sICAM-1 secretion, implicating these pathways and NF-κB suppression in the effects of oleuropein. These results indicate that oleuropein shows potential for the prevention and treatment of inflammatory diseases of the retina.

Astragaloside IV suppresses inflammatory response via suppression of NF-κB, and MAPK signalling in human bronchial epithelial cells.

CONTEXT: Astragaloside IV isolated from Astragalus membranaceus (Fisch.), which was reported to have anti-tumor, anti-asthma, and suppressed cigarette smoke-induced lung inflammation in mice. OBJECTIVES: This study investigated whether astragaloside IV reduced the expression of inflammatory mediators and oxidative stress in BEAS-2B cells. METHODS: BEAS-2B cells treated with astragaloside IV, and then stimulated with TNF-α or TNF-α/IL-4. The levels of cytokine and chemokine were analysed with ELISA and real-time PCR. RESULTS: Astragaloside IV significantly inhibited the levels of CCL5, MCP-1, IL-6 and IL-8. Astragaloside IV also reduced ICAM-1 expression for blocked THP-1 monocyte adhesion to BEAS-2B cells. Furthermore, astragaloside IV attenuated the phosphorylation of MAPK, and reduced the translocation of p65 into the nucleus. Astragaloside IV could increase the expression of HO-1 and Nrf2 for promoting the oxidant protective effect. CONCLUSION: Aastragaloside IV has an anti-inflammatory and oxidative effect via regulated NF-κB, MAPK and HO-1/Nrf2 signalling pathways in human bronchial epithelial cells.

Tomatidine Improves Pulmonary Inflammation in Mice with Acute Lung Injury.

Tomatidine, which is isolated from green tomato, can ameliorate inflammation and oxidative stress in cells and animal experiments and has been shown to improve airway inflammation in a murine model of asthma. Here, we investigated whether tomatidine can ameliorate acute lung injury in mice. Mice were given tomatidine by intraperitoneal injection for 7 consecutive days, and then, lung injury was induced via intratracheal instillation of lipopolysaccharide (LPS). Tomatidine reduced inflammatory cytokine expressions in bronchoalveolar lavage fluid (BALF), attenuated neutrophil infiltration in the BALF and lung tissue, increased superoxide dismutase activity and glutathione levels, and alleviated myeloperoxidase expression in the lung tissue of mice with lung injury. Tomatidine also decreased inflammatory cytokine and chemokine gene expression in inflammatory lungs and attenuated the phosphorylation of mitogen-activated protein kinase and nuclear factor kappa B. Furthermore, tomatidine enhanced the production of heme oxygenase-1, decreased the secretion of inflammatory cytokines and chemokines in LPS-stimulated lung epithelial cells, and attenuated THP-1 monocyte adhesion. Our findings suggest that tomatidine attenuates oxidative stress and inflammation, improving acute lung injury in mice.

Fucoxanthin Ameliorates Oxidative Stress and Airway Inflammation in Tracheal Epithelial Cells and Asthmatic Mice.

Fucoxanthin is isolated from brown algae and was previously reported to have multiple pharmacological effects, including anti-tumor and anti-obesity effects in mice. Fucoxanthin also decreases the levels of inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) of asthmatic mice. The purpose of the present study was to investigate the effects of fucoxanthin on the oxidative and inflammatory responses in inflammatory human tracheal epithelial BEAS-2B cells and attenuated airway hyperresponsiveness (AHR), airway inflammation, and oxidative stress in asthmatic mice. Fucoxanthin significantly decreased monocyte cell adherence to BEAS-2B cells. In addition, fucoxanthin inhibited the production of pro-inflammatory cytokines, eotaxin, and reactive oxygen species in BEAS-2B cells. Ovalbumin (OVA)-sensitized mice were treated by intraperitoneal injections of fucoxanthin (10 mg/kg or 30 mg/kg), which significantly alleviated AHR, goblet cell hyperplasia and eosinophil infiltration in the lungs, and decreased Th2 cytokine production in the BALF. Furthermore, fucoxanthin significantly increased glutathione and superoxide dismutase levels and reduced malondialdehyde (MDA) levels in the lungs of asthmatic mice. These data demonstrate that fucoxanthin attenuates inflammation and oxidative stress in inflammatory tracheal epithelial cells and improves the pathological changes related to asthma in mice. Thus, fucoxanthin has therapeutic potential for improving asthma.

Tomatidine ameliorates obesity-induced nonalcoholic fatty liver disease in mice.

Tomatidine is isolated from the leaves and green fruits of some plants in the Solanaceae family, and has been reported to have anti-inflammatory and antitumor effects. Previous studies have found that tomatidine decreases hepatic lipid accumulation via regulation of vitamin D receptor and activation of AMP-activated protein kinase (AMPK) phosphorylation. However, whether tomatidine reduces weight gain and improves nonalcoholic fatty liver disease (NAFLD) remains unclear. In this study, we investigated how tomatidine ameliorates NAFLD in obese mice and evaluated the regulatory mechanism of lipogenesis in hepatocytes. Male C57BL/6 mice were fed a high-fat diet (HFD) to induce obesity and NAFLD, and treated with tomatidine via intraperitoneal injection. In vitro, FL83B hepatocytes were incubated with oleic acid and treated with tomatidine to evaluate lipid metabolism. Our results demonstrate that tomatidine significantly decreases body weight and fat weight compared to HFD-fed mice. In addition, tomatidine decreased hepatic lipid accumulation and improved hepatocyte steatosis in HFD-induced obese mice. We also found that tomatidine significantly regulated serum total cholesterol, fasting blood glucose, low-density lipoprotein, and triglyceride levels, but the serum high-density lipoprotein and adiponectin concentrations were higher than in the HFD-fed obese mice. In vivo and in vitro, tomatidine significantly suppressed the expression of fatty acid synthase and transcription factors involved in lipogenesis, and increased the expression of adipose triglyceride lipase. Tomatidine promoted the sirtuin 1 (sirt1)/AMPK signaling pathway to increase lipolysis and ß-oxidation in fatty liver cells. These findings suggest that tomatidine potentially ameliorates obesity and acts against hepatic steatosis by regulating lipogenesis and the sirt1/AMPK pathway.

Phloretin ameliorates hepatic steatosis through regulation of lipogenesis and Sirt1/AMPK signaling in obese mice.

BACKGROUND: Phloretin is isolated from apple trees and could increase lipolysis in 3T3-L1 adipocytes. Previous studies have found that phloretin could prevent obesity in mice. In this study, we investigated whether phloretin ameliorates non-alcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-induced obese mice, and evaluated the regulation of lipid metabolism in hepatocytes. METHODS: HepG2 cells were treated with 0.5 mM oleic acid to induce lipid accumulation, and then treated with phloretin to evaluate the molecular mechanism of lipogenesis. In another experiment, male C57BL/6 mice were fed normal diet or HFD (60% fat, w/w) for 16 weeks. After the fourth week, mice were treated with or without phloretin by intraperitoneal injection for 12 weeks. RESULTS: Phloretin significantly reduced excessive lipid accumulation and decreased sterol regulatory element-binding protein 1c, blocking the expression of fatty acid synthase in oleic acid-induced HepG2 cells. Phloretin increased Sirt1, and phosphorylation of AMP activated protein kinase to suppress acetyl-CoA carboxylase expression, reducing fatty acid synthesis in hepatocytes. Phloretin also reduced body weight and fat weight compared to untreated HFD-fed mice. Phloretin also reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis in obese mice. In liver tissue from obese mice, phloretin suppressed transcription factors of lipogenesis and fatty acid synthase, and increased lipolysis and fatty acid ß-oxidation. Furthermore, phloretin regulated serum leptin, adiponectin, triglyceride, low-density lipoprotein, and free fatty acid levels in obese mice. CONCLUSIONS: These findings suggest that phloretin improves hepatic steatosis by regulating lipogenesis and the Sirt-1/AMPK pathway in the liver.

Luteolin Attenuates IL-1ß-Induced THP-1 Adhesion to ARPE-19 Cells via Suppression of NF-κB and MAPK Pathways.

Cytokine-induced endothelial dysfunction leads to inflammation and vascular adhesion molecule production in retinal pigment epithelium (RPE) cells. Inflammation is a critical mediator in retinal degeneration (RD) diseases, including age-related macular degeneration (AMD), and RD progression may be prevented through anti-inflammatory activity in RPE cells. The flavonoid polyphenol luteolin (LU) has anti-inflammatory and antidiabetes activities, but its effects regarding retinal protection remain unknown. Here, we examined the ability of luteolin to alleviate markers of inflammation related to RD in cytokine-primed APPE-19 cells. We found that luteolin decreased the levels of interleukin- (IL-) 6, IL-8, soluble intercellular adhesion molecule-1 (sICAM-1), and monocyte chemoattractant protein-1 (MCP-1) and attenuated adherence of the human monocytic leukemia cell line THP-1 to IL-1ß-stimulated ARPE-19 cells. Luteolin also increased anti-inflammatory protein heme oxygenase-1 (HO-1) levels. Interestingly, luteolin induced protein kinase B (AKT) phosphorylation, thus inhibiting nuclear factor- (NF-) κB transfer from cytoplasm into the nucleus and suppressing mitogen-activated protein kinase (MAPK) inflammatory pathways. Furthermore, cotreatment with MAPK inhibitors and luteolin decreased inflammatory cytokine and chemokine levels, and further suppressed THP-1 adhesion. Overall, these results provide evidence that luteolin protects ARPE-19 cells from IL-1ß-stimulated increases of IL-6, IL-8, sICAM-1, and MCP-1 production by blocking the activation of MAPK and NF-κB signaling pathways, thus ameliorating the inflammatory response.

Spilanthol from Traditionally Used Spilanthes acmella Enhances AMPK and Ameliorates Obesity in Mice Fed High-Fat Diet.

Spilanthol (SP) is a bioactive compound found in Spilanthes acmella, giving the flowers and leaves a spicy taste. Studies found that phyto-ingredients stored in spice plants act against obesity-related diseases. SP has antimicrobial, anti-inflammatory, and analgesic properties, but the effects on obesity are not yet known. We investigated the effects of SP in differentiated adipocytes (3T3-L1 cells) and mice fed a high-fat diet (HFD). SP significantly inhibited intracellular lipid accumulation and significantly reduced the expression of lipogenesis-related proteins, including acetyl-CoA carboxylase (ACC) and fatty-acid synthase (FAS). In contrast, SP increased the expression of carnitine palmitoyltransferase (CPT)1 and AMP-activated protein kinase (AMPK) in adipocytes. However, SP suppressed the levels of cyclooxygenase-2 (COX-2), phospho-p38 (pp38), and phospho-JNK (c­Jun N-terminal kinase) (pJNK) in LPS (lipopolysaccharide)-stimulated murine pre-adipocytes. SP administered to HFD-induced obese mice via intraperitoneal injections twice a week for 10 weeks decreased body weight gain, visceral adipose tissue weight, and adipocyte size. SP inhibited lipogenic proteins FAS and ACC, and suppressed adipogenic transcription factors, enhancing lipolysis and AMPK protein expression in the liver. SP has anti-obesity effects, upregulating AMPK to attenuate lipogenic and adipogenic transcription factors.

Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice.

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.

Protective Effects of Licochalcone A Ameliorates Obesity and Non-Alcoholic Fatty Liver Disease Via Promotion of the Sirt-1/AMPK Pathway in Mice Fed a High-Fat Diet.

Licochalcone A is a chalcone isolated from Glycyrrhiza uralensis. It showed anti-tumor and anti-inflammatory properties in mice with acute lung injuries and regulated lipid metabolism through the activation of AMP-activated protein kinase (AMPK) in hepatocytes. However, the effects of licochalcone A on reducing weight gain and improving nonalcoholic fatty liver disease (NAFLD) are unclear. Thus, the present study investigated whether licochalcone A ameliorated weight loss and lipid metabolism in the liver of high-fat diet (HFD)-induced obese mice. Male C57BL/6 mice were fed an HFD to induce obesity and NAFLD, and then were injected intraperitoneally with licochalcone A. In another experiment, a fatty liver cell model was established by incubating HepG2 hepatocytes with oleic acid and treating the cells with licochalcone A to evaluate lipid metabolism. Our results demonstrated that HFD-induced obese mice treated with licochalcone A had decreased body weight as well as inguinal and epididymal adipose tissue weights compared with HFD-treated mice. Licochalcone A also ameliorated hepatocyte steatosis and decreased liver tissue weight and lipid droplet accumulation in liver tissue. We also found that licochalcone A significantly regulated serum triglycerides, low-density lipoprotein, and free fatty acids, and decreased the fasting blood glucose value. Furthermore, in vivo and in vitro, licochalcone A significantly decreased expression of the transcription factor of lipogenesis and fatty acid synthase. Licochalcone A activated the sirt-1/AMPK pathway to reduce fatty acid chain synthesis and increased lipolysis and ß-oxidation in hepatocytes. Licochalcone A can potentially ameliorate obesity and NAFLD in mice via activation of the sirt1/AMPK pathway.

Licochalcone A Inhibits Cellular Motility by Suppressing E-cadherin and MAPK Signaling in Breast Cancer.

A compound isolated from Glycyrrhizauralensis, licochalcone A (LA) exhibits anti-inflammatory and anti-tumor properties in various cell lines. LA has been found to promote autophagy and suppress specificity protein 1, inducing apoptosis in breast cancer cells. However, the regulation of breast cancer cell invasion and migration by LA is elusive. Thus, the present study investigated whether LA induces apoptosis and cellular motility in MDA-MB-231 breast cells, and investigated the underlying molecular mechanisms. MDA-MB-231 cells treated with LA and cell viability measured by cell counting kit-8 assay. Apoptotic signal proteins checked by flow cytometry, fluorescent staining, and Western blot. LA effectively suppressed cell migration, and modulated E-cadherin and vimentin expression by blocking MAPK and AKT signaling. LA inhibited cell proliferation and cell cycle, modulated mitochondrial membrane potential and DNA damage, and reduced oxidative stress in MDA-MB-231 cells. LA also activated cleaved-caspase 3 and 9, significantly decreased Bcl-2 expression, ultimately causing the release of cytochrome c from the mitochondria into the cytoplasm. Overall, our findings suggest that LA decreases cell proliferation and increases reactive oxygen species production for induced apoptosis, and regulates E-cadherin and vimentin by reducing MAPK and AKT signaling, resulting in suppressed MDA-MB-231 cell migration and invasion.