European Journal of Nutrition (v.50, #3)
New mechanisms and the anti-inflammatory role of curcumin in obesity and obesity-related metabolic diseases by Adeeb Shehzad; Taewook Ha; Fazli Subhan; Young Sup Lee (151-161).
A metabolic abnormality such as obesity is a major obstacle in the maintenance of the human health system and causes various chronic diseases including type 2 diabetes, hypertension, cardiovascular diseases, as well as various cancers. This study was designed to summarize the recent scientific knowledge regarding the anti-obesity role of curcumin (diferuloylmethane), which is isolated from the herb curcuma longa, known to possess anti-inflammatory activities. However, little is known about its exact underlying molecular mechanisms in the treatment of obesity and metabolic diseases. Furthermore, cell cultures, animal models of obesity, and few human clinical and epidemiological studies have added the promise for future therapeutic interventions of this dietary compound.An electronic search was performed using Science finder, Medline, Scopus, Google scholar and collected English language articles from 2000 to 2010, relating to the role of curcumin in obesity and metabolic diseases.Obesity has been classified as a growing epidemic and its associated metabolic disorders are considered a major risk to the health system. Curcumin interacts with specific proteins in adipocytes, pancreatic cells, hepatic stellate cells, macrophages, and muscle cells, where it suppresses several cellular proteins such as transcription factor NF-kB, STAT-3, Wnt/β-catenin and activates PPAR-γ, Nrf2 cell signaling pathway. In addition, curcumin downregulates the inflammatory cytokines, resistin and leptin, and upregulates adiponectin as well as other associated proteins. The interactions of curcumin with several signal transduction pathways reverse insulin resistance, hyperglycemia, hyperlipidemia, and other inflammatory symptoms associated with obesity and metabolic diseases.The modulation of several cellular transduction pathways by curcumin has recently been extended to elucidate the molecular basis for obesity and obesity-related metabolic diseases. These findings might enable novel phytochemical treatment strategies as well as curcumin translation to the clinical practice for the treatment and prevention of obesity-related chronic diseases. Furthermore, the relatively low cost of curcumin, safety and proven efficacy make it advisable to include curcumin as part of healthy diet.
Keywords: Curcumin; Obesity; Inflammation; Adipocytes; Adiponectin
Immunoregulatory effects of the flavonol quercetin in vitro and in vivo by Thomas Nickel; Henner Hanssen; Zeljka Sisic; Susanne Pfeiler; Claudia Summo; Daniel Schmauss; Eva Hoster; Michael Weis (163-172).
Atherosclerosis is known to be an inflammatory disease. Dendritic cells (DCs) are essential for the regulation of the immune system. Up to 10% of the cells in atherosclerotic plaques are DCs. The cardiovascular protective effects of flavonoids (tea, wine) may be mediated by anti-inflammatory mechanisms that affect DC regulation. We aimed to characterize the impact of the flavonol quercetin on DC activity and differentiation in vitro and in vivo.For the in vitro experiments, we used murine DCs and endothelial cells to study adhesion properties. For all other experiments (DC phagocytosis capacity, DC maturation, DC differentiation (BDCA-1/-2) and NF-kB-activation), human monocyte-derived DCs were used. The cells were incubated with quercetin (10 μmol/L) ± oxLDL (10 μg/mL) between 24 and 48 h. For in vivo experiments, eight healthy male volunteers took 500 mg of quercetin twice daily over 4 weeks, five healthy male volunteers served as control. Before and after intake, blood samples were collected. Peripheral blood leukocytes were isolated (analyses of DC differentiation), and plasma was immediately frozen.Quercetin reduced DC adhesion (−42%; p < 0.05) and expression of CD11a (−21%; p < 0.05). OxLDL-induced DC differentiation was partially inhibited by quercetin (BDCA-1–29%; BDCA-2–33%; p < 0.05). These effects were achieved by compensation of oxLDL-induced up-regulation of NF-kB by quercetin. The 4-week treatment with quercetin resulted in relevant plasma levels (2.47 μmol/L) and reduced BDCA-2 + DCs in the peripheral blood by 42% (p < 0.05) as well as systemic levels of the NO-synthase inhibitor asymmetric dimethylarginine (−31%, p < 0.05).In vitro, quercetin reduced DC adhesion and oxLDL-induced DC differentiation. In vivo, quercetin reduced circulating plasmacytoid DCs and systemic ADMA-levels. The immunoregulatory effects of quercetin may contribute to the anti-atherosclerotic potential of flavonols.
Keywords: Quercetin; Flavonoids; Dendritic cells; Atherosclerosis
Is dietary fat associated with the risk of colorectal cancer? A meta-analysis of 13 prospective cohort studies by Liu Liu; Wen Zhuang; Ruo-Qi Wang; Rajarshi Mukherjee; Shuo-Meng Xiao; Zhong Chen; Xiao-Ting Wu; Yong Zhou; Hai-Yan Zhang (173-184).
The results of animal studies suggest there is a significant role for dietary fat in the development of colorectal cancer (CRC). However, inconsistent results have been reported by epidemiological studies.To evaluate the association between total dietary fat and risk of colorectal cancer development using a meta-analysis based on prospective cohort studies.Published literature was retrieved from Medline, Embase and CNKI (China Knowledge Resource Integrated Database) databases updated to 1st May, 2009. Overall, thirteen prospective cohort studies with 3,635 cases and 459,910 participants were included.The combined relative risk (RR) [95% confidence interval (95%CI)] for the risk of CRC was 0.99 (0.89,1.09) when the highest level of total dietary fat was versus (vs.) the lowest level. Stratified analyses according to gender, ethnicity, country and age showed that the highest level of total dietary fat did not increase the risk of CRC [RR (95%CI): 0.89 (0.77,1.03) for males; 1.09 (0.94,1.26) for females; 1.08 (0.94,1.25) for Caucasians; 0.90 (0.77,1.04) for Asians; 1.13 (0.94,1.36) for Americans; 0.92 (0.81,1.04) for individuals older than 40]. Besides those, the highest level of total fat diet also did not increase the risk of neither colon cancer [RR (95%CI): 0.96 (0.82,1.13)] nor rectal cancer [RR (95%CI):1.07 (0.63,1.82)]. Furthermore, neither animal fat nor plant fat were associated with the risk of CRC [RR (95%CI): 1.05 (0.91–1.22) for animal fat and 0.96 (0.82–1.11) for plant fat].This meta-analysis suggests that dietary fat may not be associated with the increased risk of CRC. More well-designed studies with larger population performed among Asians are needed to further evaluate the associations. In addition, probable bias caused by measurement error should be noticed in this meta-analysis, and measurement error needs to be adjusted in the future studies.
Keywords: Colorectal cancer; Dietary fat; Cohort study; Meta-analysis
Omega-3 fatty acids and lipoprotein associated phospholipase A2 in healthy older adult males and females by T. L. Nelson; J. E. Hokanson; M. S. Hickey (185-193).
Lipoprotein associated phospholipase A2 (Lp-PLA2) is a novel inflammatory factor that has been independently associated with stroke and cardiovascular disease (CVD). Omega-3 fats have been implicated in reducing inflammation associated with CVD. The aim of this study was to determine if an 8-week isocaloric diet supplemented with eicosapentaenoic acid (EPA) and docosahexaenoic (DHA) in the form of fish oil or α-linolenic acid (ALA) in the form of flaxseed oil would alter Lp-PLA2 among healthy adults ages 50 years and older.Fifty-nine healthy adults (~75% female, average age 61 years) were randomized to one of three groups with equal amounts of total fat intake. All capsules contained ~1 g of fat. The control group (n = 19) consumed olive oil capsules (~11 g/day); the ALA group (n = 20) consumed flaxseed oil capsules (~11 g/day) and the EPA/DHA group (n = 20) consumed fish oil capsules (~2 g/day + 9 g/day of olive oil). Fasting blood samples were obtained before and after the 8-week intervention for determination of Lp-PLA2 mass and activity as well as lipid values.We did not find any significant changes in Lp-PLA2 mass or activity after the intervention in any of the groups; however, change in oxidized LDL was associated with change in Lp-PLA2 mass (r = 0.37, p < 0.01).Supplementing the diet with omega-3 fatty acids for 8-weeks did not influence Lp-PLA2 activity or mass among older adults; altering oxidized LDL may be necessary to see changes in Lp-PLA2 levels.
Keywords: Omega-3 fats; Inflammation; Lipids; Lipoprotein-associated phospholipase A2; Healthy adults
Breast milk tocopherol content during the first six months in exclusively breastfeeding Greek women by Angeliki Antonakou; Antonia Chiou; Nikolaos K. Andrikopoulos; Chrysa Bakoula; Antonia-Leda Matalas (195-202).
To determine tocopherol and fat content of Greek mother’s milk during the first 6 months of exclusive breastfeeding and correlate with maternal diet characteristics.Milk samples and dietary records were obtained by mothers at 1st (n = 64), 3rd (n = 39) and 6th (n = 23) month postpartum. Milk tocopherol content was determined by high-performance liquid chromatography method (HPLC) and fat content by the crematocrit method.Milk’s α-tocopherol content at 1st, 3rd and 6th month postpartum was 8.3 ± 3.4, 8.1 ± 4.2 and 8.5 ± 4.7 μmol/L, while total tocopherol values were 8.9 ± 3.6, 8.7 ± 4.6 and 9.5 ± 5.6 μmol/L, respectively, and were closely related to milk’s fat content. No significant differences were observed for α- and total tocopherol content in breast milk among the three time points. Maternal vitamin E dietary intake was 7.2 ± 3.7, 6.8 ± 3.5 and 10.9 ± 5.2 mg/day at 1st, 3rd and 6th month postpartum, respectively. Though vitamin E dietary intake was less than the recommended one, vitamin E content in breast milk was considered sufficient for infant needs. Milk tocopherol content was found to be associated only with mothers’ total fat and saturated fat dietary intake.This study is among few in literature to determine tocopherol content of breast milk in European women and detect dietary factors that may influence its values. The only maternal dietary characteristic to affect breast milk tocopherol content was mothers’ total fat intake, while tocopherol intake seems to have no effect.
Keywords: Vitamin E; Tocopherols; Breast milk; Mediterranean diet
Randomised, double-blind and placebo-controlled study using new probiotic lactobacilli for strengthening the body immune defence against viral infections by Anna Berggren; Irini Lazou Ahrén; Niklas Larsson; Gunilla Önning (203-210).
The aim of this study was to investigate whether consumption of Lactobacillus plantarum HEAL 9 (DSM 15312) and Lactobacillus paracasei 8700:2 (DSM 13434) could affect naturally acquired common cold infections in healthy subjects.A randomised, parallel, double-blind placebo-controlled study was performed to investigate whether intake of this probiotic mixture could reduce the risk of common cold episodes, number of days with common cold symptoms, frequency and severity of symptoms, and cellular immune response in common cold infections. A total of 272 subjects were supplemented daily with either 109 cfu (colony forming units) of probiotics (N = 135) or control (N = 137) for a 12-week period.The incidence of acquiring one or more common cold episode was reduced from 67% in the control group to 55% in the probiotic group (p < 0.05). Also, the number of days with common cold symptoms were significantly (p < 0.05) reduced from 8.6 days in the control group to 6.2 days, in the probiotic group, during the 12-week period. The total symptom score was reduced during the study period from a mean of 44.4 for the control group to 33.6 for the probiotic group. The reduction in pharyngeal symptoms was significant (p < 0.05). In addition, the proliferation of B lymphocytes was significantly counteracted in the probiotic group (p < 0.05) in comparison with the control group.In conclusion, intake of the probiotic strains Lactobacillus plantarum HEAL 9 (DSM 15312) and Lactobacillus paracasei 8700:2 (DSM 13434) reduces the risk of acquiring common cold infections.
Keywords: Probiotic; Immune defence; Common cold; Lactobacillus plantarum ; Lactobacillus paracasei ; DSM 15312; DSM 13434
The presence of ochratoxin A in cord serum and in human milk and its correspondence with maternal dietary habits by G. Biasucci; G. Calabrese; R. Di Giuseppe; G. Carrara; F. Colombo; B. Mandelli; M. Maj; T. Bertuzzi; A. Pietri; F. Rossi (211-218).
Ochratoxin A (OTA) is a mycotoxin present in food that can be found in human blood and milk.The link between the nutritional habits of pregnant women both of Italian and foreign nationality resident in Italy and the presence of ochratoxin A in cord blood and in maternal milk was investigated.The study involved 130 pregnant women. Food consumption during pregnancy was evaluated by means of the EPIC questionnaire; OTA content was determined in cord serum and maternal milk by HPLC.The mean daily dietary intake of OTA was 1.02 ± 1.20 and 0.87 ± 0.78 ng/kg of bodyweight for Italian and non-Italian women, respectively, but this difference was not statistically significant. The incidence of positive milk samples was 73.0 and 85.0% among the Italian and non-Italian mothers, respectively. Pork meat, soft drinks, sweets and red wine showed a significant relationship with OTA level in serum. As far as milk is concerned, a positive relationship resulted for pork meat, sweets, soft drinks and seed oils. A positive relationship between serum OTA level and the ratio serum/milk OTA was found. The intake of OTA had no effect on the cord blood creatinine level.This study confirms that OTA is widely present in human milk and therefore could pose a risk for the newborn.
Keywords: Ochratoxin; Human milk; Serum; Dietary habits; Creatinine