• Journal of Ginseng Research
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• v.46 no.4
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• pp.561-571
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• 2022

Background: Ginsenoside Rb1 (GRb1) is capable of regulating lipid and glucose metabolism through its action on adipocytes. However, the beneficial role of GRb1-induced up-regulation of adiponectin in liver steatosis remains unelucidated. Thus, we tested whether GRb1 ameliorates liver steatosis and insulin resistance by promoting the expression of adiponectin. Methods: 3T3-L1 adipocytes and hepatocytes were used to investigate GRb1's action on adiponectin expression and triglyceride (TG) accumulation. Wild type (WT) mice and adiponectin knockout (KO) mice fed high fat diet were treated with GRb1 for 2 weeks. Hepatic fat accumulation and function as well as insulin sensitivity was measured. The activation of AMPK was also detected in the liver and hepatocytes. Results: GRb1 reversed the reduction of adiponectin secretion in adipocytes. The conditioned medium (CM) from adipocytes treated with GRb1 reduced TG accumulation in hepatocytes, which was partly attenuated by the adiponectin antibody. In the KO mice, the GRb1-induced significant decrease of TG content, ALT and AST was blocked by the deletion of adiponectin. The elevations of GRb1-induced insulin sensitivity indicated by OGTT, ITT and HOMA-IR were also weakened in the KO mice. The CM treatment significantly enhanced the phosphorylation of AMPK in hepatocytes, but not GRb1 treatment. Likewise, the phosphorylation of AMPK in liver of the WT mice was increased by GRb1, but not in the KO mice. Conclusions: The up-regulation of adiponectin by GRb1 contributes to the amelioration of liver steatosis and insulin resistance, which further elucidates a new mechanism underlying the beneficial effects of GRb1 on obesity.

• Korean Journal of Community Nutrition
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• v.19 no.1
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• pp.12-26
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• 2014

The purpose of this study was to investigate the relationships among serum adiponectin, leptin and vitamin D concentrations and the metabolic syndrome in Korean farmers. 105 (26 males, 79 females) farmers (39~78 years, mean age $59.4{\pm}9.6$ years) in Gangwon - area were included in this study. Anthropometric measurements and biochemical blood analysis of subjects were carried out. The prevalence of obesity, abdominal obesity, hypertension, diabetes, hypertriglyceridemia, hypercholesterolemia and hyper LDL-cholesterolemia, metabolic syndrome were 51.9%, 65.7%, 49.5%, 15.3%, 17.3%, 13.5%, 11.5% and 40.9%, respectively. Serum adiponectin and leptin levels ($8.90{\mu}g/ml$ and 12.6 ng/ml) of females were significantly higher than those ($6.49{\mu}g/ml$ and 4.88 ng/ml) of males. But there was no significant difference in 25(OH)vitamin D concentration between males (15.4 ng/ml) and females (16.9 ng/ml). In the subjects with metabolic syndrome, the adiponectin levels were significantly lower and leptin levels were significantly higher than those of the subjects without metabolic syndrome. Serum adiponectin level had positive correlations with HDL-cholesterol level (r = 0.325, p < 0.001), but showed negative correlations with triglyceride and fasting blood glucose concentrations, body weight and waist/hip circumference ratio (r = -0.202 ~ -0.317, p < 0.05). Serum leptin and 25(OH)vitamin D concentrations were positively correlated with body fat (kg, %) and BMI, waist and hip circumferences (r = 0.244 ~ 0.682, p < 0.001). The results of this study suggested that adiponectin and leptin levels could be credible indices to predict chronic diseases in farmers. However, further research on vitamin D should be carried out considering another factors.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.588-593
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• 2004

The gene expression of porcine adiponectin and stearoyl coenzyme A desaturase (SCD) was investigated in this study. The partial gene sequences for adiponectin and SCD were amplified by RT-PCR from subcutaneous adipose tissue and cloned by TA cloning techniques. Sequences of these genes were determined and found to be highly homologous to that of other species, suggesting similar function of these genes as in other species. The transcripts of these adipocyte-related genes in pig tissues were measured by Northern analysis. The transcripts for adiponectin and SCD were highly expressed in porcine subcutaneous adipose tissue; the transcripts for SCD were also barely detected in the liver, but the greatest concentrations were in the adipose tissue. In porcine stromalvascular cells (S/V cells) cultured in vitro, transcripts for adiponectin and SCD increased gradually during adipocyte differentiation. The level of adipocyte adiponectin mRNA was associated with late adipocyte differentiation, indicating the gene may not be involved in adipocyte differentiation but has great importance in porcine adipocyte functions. The SCD transcripts were not detectable until 2 d after induction of adipocyte differentiation. It was highly expressed in differentiating porcine adipocytes (2 to 10 d after the induction of adipocyte differentiation), indicating a significant role of SCD in adipocytes.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.446-457
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• 2018

Adiponectin, a hormone predominantly originated from adipose tissue, has exhibited potent anti-inflammatory properties. Accumulating evidence suggests that autophagy induction plays a crucial role in anti-inflammatory responses by adiponectin. However, underlying molecular mechanisms are still largely unknown. Association of Bcl-2 with Beclin-1, an autophagy activating protein, prevents autophagy induction. We have previously shown that adiponectin-induced autophagy activation is mediated through inhibition of interaction between Bcl-2 and Beclin-1. In the present study, we examined the molecular mechanisms by which adiponectin modulates association of Bcl-2 and Beclin-1 in macrophages. Herein, we demonstrated that globular adiponectin (gAcrp) induced increase in the expression of AUF1 and ZFP36L1, which act as mRNA destabilizing proteins, both in RAW 264.7 macrophages and primary peritoneal macrophages. In addition, gene silencing of AUF1 and ZFP36L1 caused restoration of decrease in Bcl-2 expression and Bcl-2 mRNA half-life by gAcrp, indicating crucial roles of AUF1 and ZFP36L1 induction in Bcl-2 mRNA destabilization by gAcrp. Moreover, knock-down of AUF1 and ZFP36L1 enhanced interaction of Bcl-2 with Beclin-1, and subsequently prevented gAcrp-induced autophagy activation, suggesting that AUF1 and ZFP36L1 induction mediates gAcrp-induced autophagy activation via Bcl-2 mRNA destabilization. Furthermore, suppressive effects of gAcrp on LPS-stimulated inflammatory mediators expression were prevented by gene silencing of AUF1 and ZFP36L1 in macrophages. Taken together, these results suggest that AUF1 and ZFP36L1 induction critically contributes to autophagy induction by gAcrp and are promising targets for anti-inflammatory responses by gAcrp.

• Korean Journal of Community Nutrition
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• v.16 no.1
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• pp.126-135
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• 2011

Obesity is characterized by increased storage of fatty acids in an adipose tissue and closely associated with the development of insulin resistance and cardiovascular diseases (CVD) through secretion of adipokines. This study was done to compare serum insulin, leptin, adiponectin and high sensitivity C-reactive protein (hs-CRP) levels according to body masss index (BMI) in Korean adult women aged 19 to 50. In addition, we examined the association of BMI, serum lipids and Homa-IR with serum adiponectin, leptin and hs-CRP levels. The subjects were divided into 3 groups by their BMI, normal weight (BMI ${\leq}$ 22.9, n = 30), overweight (23.0 ${\leq}$ BMI ${\leq}$ 24.9, n = 71) and obese group (25.0 ${\leq}$ BMI, n = 59). Serum levels of total-cholesterol, TG, and LDL-cholesterol were significantly higher in obese group than in normal weight group. LDL/HDL ratio and AI were significantly higher in obese group than in normal or overweight group. Fasting serum levels of glucose and insulin and Homa-IR as a marker of insulin resistance were significantly higher in obese group than in overweight group. Serum leptin level was significantly higher in obese group while serum adiponectin level was significantly lower in obese group compared to other two groups. hs-CRP was significantly increased in obese group. Correlation data show that serum adiponectin level was positively correlated with serum HDLcholesterol level and was negatively correlated with BMI, WC, TG, LDL-cholesterol, Homa-IR, hs-CRP and leptin. In addition, serum leptin level was positively correlated with BMI, WC, glucose, insulin, Homa-IR and hs-CRP. These results might imply that the regulation of key adipokines such as adiponectin might be a strategy for the prevention or treatment of obesity-associated diseases such as diabetes and CVD.

• Journal of Pharmacopuncture
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• v.25 no.2
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• pp.130-137
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• 2022

Objectives: Insulin resistance (IR) is major cause of type 2 diabetes (T2D), and adipokines (e.g., adiponectin, leptin, and resistin) play an important role in insulin sensitivity. Medicinal plants are frequently used for T2D treatment. This study investigates the effect of Artemisia annua L. (AA) extracts on adipokines in mice with high-fat-diet (HFD)/streptozotocin (STZ)-induced T2D. Methods: We divided 60 mice into 12 groups (n = 5 per group): control, untreated T2D, treated T2D, and 9 other groups. T2D was induced in all groups, except controls, by 8 weeks of HFD and STZ injection. The treated T2D group was administered 250 mg/kg of metformin (MTF), while the nine other groups were treated with 100, 200, and 400 mg/kg of hot-water extract (HWE), cold-water extract (CWE), and alcoholic extract (ALE) of AA (daily oral gavage) along with 250 mg/kg of MTF for 4 weeks. The intraperitoneal glucose tolerance test (IPGTT) was performed, and the homeostasis model assessment of adiponectin (HOMA-AD) index and blood glucose and serum insulin, leptin, adiponectin, and resistin levels were measured. Results: Similar to MTF, all three types of AA extracts (HWEs, CWEs, and ALEs) significantly (p < 0.0001) decreased the area under the curve (AUC) of glucose during the IPGTT, the HOMA-AD index, blood glucose levels, and serum insulin, leptin, and resistin levels and increased serum adiponectin levels in the MTF group compared to the T2D group (p < 0.0001). The HWEs affected adipokine release, while the CWEs and ALEs decreased leptin and resistin production. Conclusion: Water and alcoholic AA extracts have an antihyperglycemic and antihyperinsulinemic effect on HFD/STZ diabetic mice. In addition, they decrease IR by reducing leptin and resistin production and increasing adiponectin secretion from adipocytes.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.481-487
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• 2005

Purpose : Adiponectin, adipose tissue-specific protein, has anti-inflammatory and anti-atherogenic properties. It has been found to have a negative correlation with obesity and to play a role in modulating glucose tolerance and insulin sensitivity. Serum adiponectin concentrations are decreased in adults with obesity and type 2 diabetes. We investigated the difference in adiponectin levels between obese and non-obese children, and evaluated the relationship of serum adiponectin with body mass index(BMI), serum fasting insulin, lipid profiles and homeostasis model assessment(HOMA) in children. Methods : We measured serum adiponectin levels by radioimmunoassay in 113 children(82 obese children and 31 non-obese controls) from 8 to 15 years of age, and also checked BMI, fasting serum glucose, insulin and lipid profiles. Fasting and postprandial serum adiponectin concentrations were compared by oral glucose tolerance tests in 27 obese children. The correlations of adiponectin with BMI, insulin, low density lipoprotein(LDL)-cholesterol and HOMA were analyzed by Pearson's correlation. Results : The serum adiponectin levels were significantly lower in the obese group(19.7 mg/mL) than in the non-obese group(27.5 mg/mL)(P<0.01). Serum adiponectin concentrations were negatively correlated with BMI(r=-0.39, P<0.01), serum insulin(r=-0.28, P<0.01), LDL-C(r=-0.20, P<0.01) and HOMA(r=-0.22, P<0.01). At oral glucose tolerance tests in obese children, postprandial 2 hours adiponectin level(19.8 mg/mL) was decreased compared to fasting level(25.8 mg/mL)(P<0.01). Conclusion : Serum adiponectin concentrations were inversely related to adiposity and insulin resistance in children. We suggest the serum adiponectin level could be used as an early marker of insulin resistance in obese children.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.733-741
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• 2008

In the present study, we comprehensively examined the associations of plasma levels of total adiponectin and high molecular weight (HMW) adiponectin with the features of cardiometabolic risks including body fat distribution, dyslipidemia, insulin resistance and inflammatory markers in a cross-sectional study of 110 treated hypertensive patients. Blood lipid profiles, high sensitivity C-reactive protein (hsCRP) and homeostasis model assessment of insulin resistance (HOMA- IR) derived from fasting glucose and insulin concentrations were determined. Plasma levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) were analyzed using ELISA. The results showed that plasma levels of HMW-adiponectin were negatively associated with body mass index (BMI, r = - 0.203, p < 0.05) and waist circumference (r = -0.307, p < 0.01), which was not shown in total adiponectin. Plasma levels of HMW-adiponectin were negatively associated with triglyceride (r = -0.223, p < 0.05) and positively associated with HDL-cholesterol (r = 0.228, p < 0.05). Plasma levels of adiponectin were positively associated with HDL-cholesterol (r = 0.224, p < 0.05). Plasma levels of HMW-adiponectin were negatively associated with hsCRP (r = -0.276, p < 0.01) and IL-6 (r = -0.272, p < 0.01). In addition, there were weak associations between plasma levels of HMWadiponectin and TNF-${\alpha}$ (r = -0.163, p = 0.07) and ICAM-1 (r = -0.158, p = 0.09). However, there were no significant associations of total adiponectin with inflammatory markers except hsCRP (r = -0.203, p < 0.05). Stepwise multiple linear regression analysis showed that only plasma levels of HMW-adiponectin was an independent factor influencing serum levels of hsCRP, a marker of systemic low grade inflammation, after adjusting for age, gender, BMI, waist circumference, alcohol intake, smoking status, blood lipids, total adiponectin and drug use (p < 0.01). These results suggest that HMW-adiponectin, rather than total adiponectin, is likely to be closely associated with the features of cardiometabolic risks in treated hypertensive patients and might be effective biomarker for the prediction of cardiovascular disease.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6137-6143
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• 2014

Limited numbers of epidemiological studies have examined the relationship between adipokines and breast cancer survival. Preoperative serum levels of obesity-related adipokines (leptin and adiponectin) were here measured in 370 breast cancer patients, recruited from two hospitals in Korea. We examined the association between those adipokines and disease-free survival (DFS). The TNM stage, ER status and histological grade were aslo assessed in relation to breast cancer survival. Elevated adiponectin levels were associated with reduced DFS of breast cancer ($P_{trend}=0.03$) among patients with normal body weight, predominantly in postmenopausal women. There was no association of leptin with breast cancer survival. In conclusion, our study suggests that high levels of adiponectin at diagnosis are associated with breast cancer survival among women with normal body weight.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.221-231
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• 2022

Adiponectin (Ad), a 30 kDa molecule, is an anti-diabetic adipokine; although derived from adipose tissue, it performs numerous activities in various other tissues. It binds to its own receptors, namely adiponectin receptor 1(AdipoR1), adiponectin receptor 2 (AdipoR2), and T-cadherin (CDH13). Ad plays several roles, especially as a regulator. It modulates lipid and glucose metabolism and promotes insulin sensitivity. This demonstrates that Ad has a robust correlation with fat metabolism. Furthermore, although Ad is not in direct contact with other tissues, including the skin, it can be delivered to them by diffusion or secretion via the endocrine system. Recently it has been reported that Ad can impact skin cell biology, underscoring its potential as a therapeutic biomarker of skin diseases. In the present review, we have discussed the association between skin cell biology and Ad. To elaborate further, we described the involvement of Ad in the biology of various types of cells in the skin, such as keratinocytes, fibroblasts, melanocytes, and immune cells. Additionally, we postulated that Ad could be employed as a therapeutic target to maintain skin homeostasis.