Inhibitory activities of kaempferol,galangin, carnosic acid and polydatin against glycation and α‐amylase and α‐glucosidase enzymes

The activities of four natural phenolics, kaempferol, galangin, carnosic acid and polydatin in scavenging free radicals, inhibiting advanced glycation end‐product (AGE) formation, α‐amylase and α‐glucosidase and trapping methylglyoxal (MGO), were evaluated in this study. Carnosic acid and galangin had the highest activity in scavenging free radicals. Kaempferol and galangin had the greatest activity in preventing bovine serum albumin (BSA) against glycation and reducing glycated proteins. Polydatin had the greatest performance in trapping MGO to reduce glycation reaction. However, there was no significant difference for kaempferol, galangin and carnosic acid in inhibiting AGE formation by BSA‐MGO reaction. Kaempferol, galangin and carnosic acid were the competitive inhibitors for α‐amylase, while kaempferol and carnosic acid were noncompetitive inhibitors for α‐glucosidase. However, polydatin showed as a mixed noncompetitive inhibitor for both α‐amylase and α‐glucosidase. The results indicated that the four natural phenolics have potential in inhibiting AGE production and the digestive enzymatic activity with different mechanisms.     

Cover Picture: Mol. Nutr. Food Res. 11'2010

Regular issues provide a wide range of research and review articles covering all aspects of Molecular Nutrition & Food Research. Selected topics of issue 11 are: Flavan‐3‐ol C‐glycosides – preparation and model experiments mimicking their human intestinal transit Resveratrol confers resistance against taxol via induction of cell cycle arrest in human cancer cell lines Kaempferol induced apoptosis via endoplasmic reticulum stress and mitochondria‐dependent pathway in human osteosarcoma U‐2 OS cells Diosgenin present in fenugreek improves glucose metabolism by promoting adipocyte differentiation and inhibiting inflammation in adipose tissues Plasma phospholipids n‐3 polyunsaturated fatty acid is associated with metabolic syndrome     

Sarcodon aspratus Extract Ameliorates Dextran Sulfate Sodium‐Induced Colitis in Mouse Colon and Mesenteric Lymph Nodes

Mushrooms have been previously investigated for their immune‐modulating and anti‐inflammatory properties. We examined whether the anti‐inflammatory properties of Sarcodon aspratus ethanol extract (SAE) could elicit protective effects against dextran sulfate sodium (DSS)‐induced colitis in vivo. Male C57/BL6 mice were randomly assigned to 1 of 4 treatment groups: control (CON; n = 8), DSS‐treated (DSS; n = 9), DSS+SAE at 50 mg/kg BW (SAE50; n = 8), and DSS+SAE at 200 mg/kg BW groups (SAE200; n = 9). DSS treatment induced significant weight loss, which was significantly recovered by SAE200. Although SAE did not affect DSS‐mediated reductions in colon length, it improved diarrhea and rectal bleeding induced by DSS. SAE at 200 mg/kg BW significantly attenuated IL‐6 and enhanced IL‐10 expression in mesenteric lymph nodes (MLN), and significantly reduced IL‐6 levels in splenocytes. SAE200 also significantly attenuated DSS‐induced increase in IL‐6 and IL‐1β, and reductions in IL‐10 in colon tissue. High levels of SAE were also observed to significantly decrease inflammatory COX‐2 expression that was upregulated by DSS in mice colon. These findings may have relevance for novel therapeutic strategies to mitigate inflammatory bowel disease‐relevant inflammatory responses, via the direct and indirect anti‐inflammatory activity of SAE. We also found that SAE harbors significant quantities of total fiber and β‐glucan, suggesting a possible role for these components in protection against DSS‐mediated colitis.     

Urinary trypsin inhibitor reduces inflammatory response in kidney induced by lipopolysaccharide

Human urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used in Japan as a drug for patients with acute inflammatory disorders such as septic shock and pancreatitis. Lipopolysaccharide (LPS) triggers the sepsis syndrome by activating monocytes to produce proinflammatory cytokines, including tumor necrosis factor alpha (TNFalpha), which potently stimulate the activation of neutrophils. The inhibitory mechanism of UTI on the systemic inflammatory response induced by the intraperitoneal injection of LPS in the kidney is unclear. This study was undertaken to examine the inhibitory effects of UTI on renal injury associated with the systemic inflammatory response induced by LPS stimulation, with emphasis on systemic TNFalpha and the activation of neutrophils in rat kidney. The systemic inflammatory response syndrome was induced by LPS treatment. Serum and renal TNFalpha, renal cytokine-induced neutrophil chemoattractant-1 (CINC-1) and myeloperoxidase (MPO) levels, as well as renal function after LPS stimulation, were evaluated. UTI (50,000 U/kg) inhibited LPS-induced increases in the serum and renal tissue levels of TNFalpha, as well as the renal tissue levels of CINC-1 and MPO after LPS stimulation. UTI (50,000 U/kg) also inhibited the production of serum TNFalpha associated with the systemic inflammatory response syndrome induced by LPS stimulation, thereby attenuating neutrophil infiltration into renal tissues and subsequent neutrophil-mediated renal injury. These findings may have important implications in understanding the biologic functions of UTI. UTI may prove useful in protecting against acute renal injury associated with a systemic inflammatory response.     

Suppressive effects of extracts from the aerial part of Coriandrum sativum L. on LPS‐induced inflammatory responses in murine RAW 264.7 macrophages

BACKGROUND: Coriandrum sativum is used not only as a spice to aid flavour and taste values in food, but also as a folk medicine in many countries. Since little is known about the anti‐inflammatory ability of the aerial parts (stem and leaf) of C. sativum, the present study investigated the effect of aerial parts of C. sativum on lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophages. We further explored the molecular mechanism underlying these pharmacological properties of C. sativum. RESULTS: Ethanolic extracts from both stem and leaf of C. sativum (CSEE) significantly decreased LPS‐induced nitric oxide and prostaglandin E₂ production as well as inducible nitric oxide synthase, cyclooxygenase‐2, and pro‐interleukin‐1β expression. Moreover, LPS‐induced IκB‐α phosphorylation and nuclear p65 protein expression as well as nuclear factor‐κB (NF‐κB) nuclear protein–DNA binding affinity and reporter gene activity were dramatically inhibited by aerial parts of CSEE. Exogenous addition of CSEE stem and leaf significantly reduced LPS‐induced expression of phosphorylated mitogen‐activated protein kinases (MAPKs). CONCLUSION: Our data demonstrated that aerial parts of CSEE have a strong anti‐inflammatory property which inhibits pro‐inflammatory mediator expression by suppressing NF‐κB activation and MAPK signal transduction pathway in LPS‐induced macrophages. Copyright © 2010 Society of Chemical Industry