• Animal Bioscience
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• v.35 no.5
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• pp.763-777
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• 2022

Objective: Excessive lipid accumulation in adipocytes results in prevalence of obesity and metabolic syndrome. Curcumin (CUR), a naturally phenolic active ingredient, has been shown to have lipid-lowering effects. However, its underlying mechanisms have remained largely unknown. Therefore, the study aims to determine the effect of CUR on cellular lipid accumulation in porcine subcutaneous preadipocytes (PSPA) and to clarify novel mechanisms. Methods: The PSPA were cultured and treated with or without CUR. Both cell counting Kit-8 and lactate dehydrogenase release assays were used to examine cytotoxicity. Intracellular lipid contents were measured by oil-red-o staining extraction and triglyceride quantification. Apoptosis was determined by flow cytometry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling assay. Adipogenic and apoptosis genes were analyzed by quantitative polymerase chain reaction and Western blot. Results: The CUR dose-dependently reduced the proliferation and lipid accumulation of PSPA. Noncytotoxic doses of CUR (10 to 20 μM) significantly inhibited extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and expression of adipogenic genes peroxisome proliferation-activity receptor-γ (PPAR-γ), CCAAT/enhancer binding protein-α, sterol regulatory element-binding protein-1c, adipocyte protein-2, glucose transporter-4 as well as key lipogenic enzymes fatty acid synthase and acetyl-CoA carboxylase, while ERK1/2 activation significantly reversed CUR-reduced lipid accumulation by increasing PPAR-γ. Furthermore, compared with differentiation induced media treated cells, higher dose of CUR (30 μM) significantly decreased the expression of AKT and B-cell lymphoma-2 (BCL-2), while increased the expression of BCL-2-associated X (BAX) and the BAX/BCL-2 expression ratio, suggesting triggered apoptosis by inactivating AKT and increasing BAX/BCL-2 ratio and Caspase-3 expression. Moreover, AKT activation significantly rescued CUR inhibiting lipid accumulation via repressing apoptosis. Conclusion: These results demonstrate that CUR is capable of suppressing differentiation by inhibiting ERK1/2-PPAR-γ signaling pathway and triggering apoptosis via decreasing AKT and subsequently increasing BAX/BCL-2 ratio and Caspase-3, suggesting that CUR provides an important method for the reduction of porcine body fat, as well as the prevention and treatment of human obesity.

• Journal of Life Science
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• v.24 no.8
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• pp.827-836
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• 2014

There is a rising trend in obesity due to various factors, including changes in eating habits, lack of exercise, and genetic and psychological factors. Citrus peel has been reported to prevent obesity via antioxidative, antihypertensive, and LDL cholesterol-lowering effects. This study investigated the effects of citrus peel extract fermented with or without Aspergillus oryzae in a mouse model of diet-induced obesity. The animals were divided into four groups: a high-fat diet group (HFD), a normal fat diet (NFD) group, a citrus peel extract (CP) group, and a citrus peel extract fermented with A. oryzae (CPA) group. The citrus peel extract improved lipid metabolism and weight loss in the high-fat diet-induced obese mouse model. As expected, the body weight was higher in the HFD group compared with the NFD, CP, and CPA groups. However, the concentrations of total cholesterol (TG) and triglyceride (TC) in the serum and liver of the CP and CPA groups were lower than in the HFD group. There were no significant differences in the HDL cholesterol concentration among the groups. Taken together, our results suggest that extract of citrus peel biotransformed with A. oryzae had more antiobesity activity than citrus peel not transformed by A. oryzae through the fermentation of metabolites.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.511-517
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• 2010

This study was performed to estimate the prevalence and the risk factors of metabolic syndrome in Andong rural area. A total of 1,431 people (533 males, 898 females) aged over 45 years participated in this study in 2003. The prevalence of metabolic syndrome was 38.2% (male 23.5%, female 46.9%, p<0.001). As age increased, the prevalence of the metabolic syndrome increased in female, but not in male. The major underlying components of metabolic syndrome were high blood pressure (67.1%), low HDL-cholesterol (60.6%), and abdominal obesity (39.9%). The distinctive component for male was high blood pressure (70.1%), and for female, low HDL-cholesterol (73.6%), high blood pressure (65.3%), and abdominal obesity (54.5%). Subjects having more than one component were 94.7%. The risk factors for metabolic syndrome were analyzed using the multiple logistic regression method according to gender and expressed as age-adjusted odds ratio (OR). The results of comparing female to male (OR=2.953), and of comparing obese by % body fat (M: OR=5.786, F: OR=13.498) or BMI (M: OR=3.782, F: OR=13.301) to normal body weight showed significantly higher risk for metabolic syndrome (p<0.001). Health related habits, such as smoking, alcohol drinking, and exercise, didn't show any effect on metabolic syndrome. This study revealed that the prevalence of metabolic syndrome was significantly higher in female subjects compared to both male and female, and high blood pressure was the main cause of metabolic syndrome. We suggest that the strategy for prevention or reducing the prevalence of metabolic syndrome in this area should be concentrated on reducing high blood pressure through lowering obesity and abdominal obesity.