Improvement of lipopolysaccharide-induced hepatic injuries and inflammation with mulberry extracts

Improving the Effects of Mulberry Leaves and Neochlorogenic Acid on Glucotoxicity-Induced Hepatic Steatosis in High Fat Diet Treated db/db Mice

There are many complications of type 2 diabetes mellitus. Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are two complications related to the increased lipid accumulation in the liver. Previous studies have shown that mulberry leaf water extract (MLE) has the effect of lowering lipid levels in peripheral blood, inhibiting the expression of fatty acid synthase (FASN) and increasing the activity of liver antioxidant enzymes superoxide dismutase (SOD) and catalase. Our study aimed to investigate the role of MLE and its main component, neochlorogenic acid (nCGA), in reducing serum lipid profiles, decreasing lipid deposition in the liver, and improving steatohepatitis levels. We evaluated the antioxidant activity including glutathione (GSH), glutathione reductase (GRd), glutathione peroxidase (GPx), glutathione S-transferase (GST), and superoxide dismutase (SOD), and catalase was tested in mice fed with MLE and nCGA. The results showed a serum lipid profile, and fatty liver scores were significantly increased in the HFD group compared to the db/m and db mice groups, while liver antioxidant activity significantly decreased in the HFD group. When fed with HFD + MLE or nCGA, there was a significant improvement in serum lipid profiles, liver fatty deposition conditions, steatohepatitis levels, and liver antioxidant activity compared to the HFD group. Although MLE and nCGA do not directly affect the blood sugar level of db/db mice, they do regulate abnormalities in lipid metabolism. These results demonstrate the potential of MLE/nCGA as a treatment against glucotoxicity-induced diabetic fatty liver disease in animal models.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Inflammation Induced by Lipopolysaccharide and Palmitic Acid Increases Cholesterol Accumulation via Enhancing Myeloid Differentiation Factor 88 Expression in HepG2 Cells

Recently, multiple studies have shown that chronic inflammation disturbs cholesterol homeostasis and promotes its accumulation in the liver. The underlying molecular mechanism remains to be revealed. The relationship between the toll-like receptor 4 (TLR4) inflammatory signaling pathway and cholesterol accumulation was investigated in HepG2 cells treated with lipopolysaccharide (LPS) or palmitic acid (PA) for different lengths of time. In addition, the effects of pretreatment with 20μmol/L ST2825 (MyD88 inhibitor) were also studied in LPS- or PA-treated HepG2 cells and myeloid differentiation factor 88 (MyD88)-overexpressing HEK293T cells. The intracellular total and free cholesterol levels were measured using a commercial kit and filipin staining, respectively. The expression levels of sterol regulatory element-binding protein-2 (SREBP-2) and components in the TLR4 signaling pathway were determined using Western blotting. The treatments with LPS for 12 h and with PA for 24 h significantly increased the contents of intracellular total and free cholesterol, as well as the expression levels of SREBP-2 and components in the TLR4 signaling pathway. The inhibition of MyD88 by ST2825 significantly decreased the cholesterol content and the expression levels of SREBP-2 and components of the TLR4/MyD88/NF-κB pathway in HepG2 cells, as well as MyD88-overexpressing HEK293T cells. These results indicated that LPS and PA treatments increase SREBP-2-mediated cholesterol accumulation via the activation of the TLR4/MyD88/NF-κB signaling pathway in HepG2 cells.

Dihydromyricetin attenuates Escherichia coli lipopolysaccharide-induced ileum injury in chickens by inhibiting NLRP3 inflammasome and TLR4/NF-κB signalling pathway

Lipopolysaccharide (LPS) as a major component of Escherichia coli cell wall can cause inflammation and cell death. Dihydromyricetin (ampelopsin, DHM) is a natural flavonoid compound with anti-inflammatory, anti-oxidant and anti-bacterial effects. The preventive effects of DHM against ileum injury remain unclear. Here, we explored the protective role of DHM against LPS-induced ileum injury in chickens. In this study, DHM significantly attenuated LPS-induced alteration in diamine oxidase, malondialdehyde, reduced glutathione, glutathione peroxidase and superoxide dismutase levels in chicken plasma and ileum. Histology evaluation showed that the structure of blood vessels in ileum was seriously fragmented and presence of necrotic tissue in the lumen in the LPS group. Scanning electron microscopic observation revealed that the surface of the villi was rough and uneven, the structure was chaotic, and the normal finger shape was lost in the LPS group. In contrast, 0.05% and 0.1% DHM treatment partially alleviated the abnormal morphology. Additionally, DHM maintained the barrier function by restoring the protein expression of occludin, claudin-1 and zonula occludens protein-1. DHM inhibited apoptosis through the reduction of the expression of bax and caspase-3 and restored the expression of bcl-2. Importantly, DHM could reduce ileum NLR family pyrin domain-containing 3 (NLRP3), caspase-1, interleukin (IL)-1β and IL-18 expression to protect tissues from pyroptosis and inhibited toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signalling pathway. In summary, DHM attenuated the ileum mucosal damage, oxidative stress and apoptosis, maintained barrier function, inhibited NLRP3 inflammasome and TLR4/NF-κB signalling pathway activation triggered by Escherichia coli LPS.

A mixture of mulberry and silk amino acids protected against D-galactosamine induced acute liver damage by attenuating oxidative stress and inflammation in HepG2 cells and rats

The liver is an important organ for the removal of toxins and utilization of nutrients. The present study then investigated whether a mixture of mulberry water extracts and silk amino acids protected against acute liver damage in rats induced by intraperitoneal injection of D-galactosamine and the action mechanism. D-galactosamine injection is widely used to develop experimental animal models of acute hepatic disease. In the present study, male Sprague-Dawley rats received intraperitoneal injection of D-galactosamine followed by 200 and 600 mg/kg body weight (BW) of mulberry extracts and silk amino acids (1:3, w/w; MS1:3-L and MS1:3-H), the same amounts of MS with different ratios (1:5, w/w; MS1:5-L and MS1:5-H), and 600 mg/kg bw cellulose (control) for 1 week. The normal-control group received an injection of saline instead of D-galactosamine with the same diet as the control group. D-galactosamine injection (control rats) increased serum ALT, AST and γ-GPT levels, indicating the induction of acute liver damage. The control rats also exhibited reduced glycogen depositions, which contributed to increasing fat synthesis from glucose and elevated serum triglyceride levels. Oxidative stress and inflammation in the liver of the control increased in response to the decreasing antioxidant activity and mRNA expression and increasing TNF-α expression, respectively. Both MS1:3 and MS1:5 reduced serum ALT, AST and γ-GPT levels to ameliorate liver damage. MS1:3 reduced oxidative stress by increasing the activity and expression of antioxidant enzymes, whereas MS1:5 decreased the expression TNF-α in the liver. MS1:3 and MS1:5 improved the necrosis of hepatocytes in H&E staining, which was associated with increased glycogen deposition in PAS staining. MS1:5 had better effects on glycogen accumulation. In conclusion, MS1:3 and MS1:5 can be used as therapeutic agents for acute liver damage.

Anti-Inflammatory Effects of High Hydrostatic Pressure Extract of Mulberry (Morus alba) Fruit on LPS-Stimulated RAW264.7 Cells

Mulberry fruit (Morus alba L.) contains abundant bioactive compounds, including anthocyanins and flavonols, and has been reported to possess potent beneficial properties including anticancer, antidiabetic, and anti-oxidant effects. High hydrostatic pressure (HHP) processing, a nonthermal food processing technology, is suitable for the extraction of bioactive compounds from plants. Nevertheless, the anti-inflammatory effects of HHP extract of mulberry fruit (HM) in RAW264.7 cells remain unclear. The present study aimed to investigate the anti-inflammatory effects of HM on lipopolysaccharide (LPS)-induced inflammation in vitro. RAW264.7 cells were treated with various concentrations (0.1-1 μg/mL) of HM in the presence or absence of LPS. HM inhibited the inflammatory mediator, nitric oxide (NO) release, and mRNA expression of nitric oxide synthase 2 (NOS2) in LPS-induced RAW264.7 cells. In addition, HM suppressed both mRNA and protein expressions of prostaglandin-endoperoxide synthase 2 (PTGS2). Moreover, it reduced the LPS-induced secretion of proinflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α. These results revealed that HM exerts anti-inflammatory effects by inhibiting several mediators and cytokines involved in the inflammatory process.

Green extraction of mulberry anthocyanin with improved stability using β-cyclodextrin

BACKGROUND

Mulberry anthocyanin is reported to possess various biological activities and it is unstable during extraction or food production. The use of organic solvents for extraction of mulberry anthocyanins may cause environmental pollution and safety concerns. Therefore, the aim of this study was to investigate the effect of a green extraction solvent (cyclodextrin) on the recovery of anthocyanin from mulberry fruits, as well as the thermal stability of anthocyanin.

RESULTS

β-Cyclodextrin (β-CD) or hydroxypropyl-β-cyclodextrin showed better anthocyanin extraction efficiency than water and ethanol aqueous solution for all tested mulberry cultivars. A molecular docking study indicated that anthocyanin (cyanidin-3-O-glucoside) was encapsulated in the cavity of β-CD, thus enhancing the solubility of anthocyanin. The extraction process was subsequently optimized using a Box-Behnken design. The optimal extraction conditions for anthocyanin and antioxidant activity were found at extraction temperature of 20 °C, extraction time of 44.95 min and β-CD concentration of 45 g L^-1 . Furthermore, a degradation kinetic study demonstrated that addition of β-CD could significantly improve the thermal stability of anthocyanin during extraction, with the activation energy of anthocyanin degradation increasing from 63.06 to 76.77 kJ mol^-1 .

CONCLUSIONS

Overall, our study suggests that β-CD is an alternative green extraction solvent for the recovery of anthocyanins, and addition of β-CD may potentially increase the thermal stability of anthocyanin during the extraction, which may give guidance for functional beverage production. © 2018 Society of Chemical Industry.

Mulberry water extract regulates the osteoblast/osteoclast balance in an ovariectomic rat model

Mulberry has favorable antioxidant ability.

Flavan-3-ols, anthocyanins, and inflammation

The process of inflammation constitutes a reactive response of the organism to tissue damage and is an important factor making part of a number of degenerative pathologies as insulin resistance, dyslipidemia, and hypertension, all of them comprised in the metabolic syndrome. There is an increasing interest in plant products rich in flavan-3-ols and anthocyanins because of their potential beneficial effects observed in epidemiological studies against inflammatory-related diseases. Their anti-inflammatory effects are exerted by modulation of cell redox status and inhibition of signaling pathways as NF-κB activation. The effects depend on their concentrations in target tissues and hence the bioavailability pathways followed by each particular compound. In this sense, in vitro studies performed with parental compounds at doses exceeding to those found in vivo may be drawing erroneous conclusions about their real efficacy. Contradictory results have been observed in human intervention trials, which may be ascribed to the type of population studied, length of study, source of flavan-3-ol/anthocyanin, and dose provided. Human studies are required to confirm the positive effects found in vitro and in animal models. Future research should be focused on the understanding of dose/flavonoid intake-response relationship with pharmacokinetic studies, evaluating proper biomarkers of intake. Long-term dietary interventions are necessary to observe effects on markers of late activation as well as the possible preventive effects of these compounds on long-term inflammation-related diseases.

Mulberry ( sang shèn zǐ) and its bioactive compounds, the chemoprevention effects and molecular mechanisms in vitro and in vivo

Mulberry ( sāng shèn zǐ), a traditional Chinese medicine (TCM) in Taiwan, has many bioactive substances, including polyphenol and anthocyanins compounds. Over the past decade, many scientific and medical studies have examined mulberry fruit for its antioxidation and antiinflammation effects both in vitro and in vivo. This review thus focuses on the recent advances of mulberry extracts (MEs) and their applications in the prevention and treatment of human cancer, liver disease, obesity, diabetes, and cardiovascular disease. The ME modulates several apoptotic pathways and matrix metalloproteinases (MMPs) to block cancer progression. Mulberry can increase detoxicated and antioxidant enzyme activities and regulate the lipid metabolism to treat hepatic disease resulting from alcohol consumption, high fat diet, lipopolysaccharides (LPS) and CCl4 exposure. Of the various compounds in ME, cyanidin 3-glucoside (C3G) is the most abundant, and the active compound studied in mulberry research. Herein, the antioxidant and antiinflammatory actions of C3G to improve diabetes and cardiovascular disease are also discussed. These studies provide strong evidence ME may possess the bioactivity to affect the pathogenesis of several chronic diseases.