Association of PPARγ gene expression with postprandial hypertriglyceridaemia and risk of type 2 diabetes mellitus

Adipose tissue expression of UCP1 and PRDM16 genes and their association with postprandial triglyceride metabolism and glucose intolerance

AIMS

UCP1 and PRDM16 genes, primarily involved in browning of adipose tissue that can affect lipid metabolism are also associated with diabetes risk. Therefore, we planned to study the adipose tissue expression of UCP1 and PRDM 16 genes in subjects with glucose intolerance to find out its association with postprandial triglyceride (PPTg) measures and T2DM.

METHODS

A total of 30 subjects were recruited in three groups i.e., NGT, prediabetes and T2DM (NDDM + known T2DM) who were matched for age, sex and BMI. An 8-hour standardized fat challenge test was performed to study lipemic responses. UCP1 and PRDM16 genes quantification in adipose tissue was performed by real-time PCR followed by SDS PAGE.

RESULTS

UCP1 gene expression in SAT was significantly lower in T2DM and prediabetes as compared to NGT group while PRDM16 gene expression was significantly lower in T2DM group as compared to NGT group. UCP1 gene expression correlated with PPTg measures as well as with glycaemic measures while PRDM16 gene expression correlated with glycaemic measures only.

CONCLUSION

This study found downregulation of PRDM16 and UCP1 gene expression in SAT in subjects with glucose intolerance. The association of UCP1 gene expression with PPTg dysmetabolism may contribute to greater predisposition to T2DM.

The Molecular Mechanisms of Hypoglycemic Properties and Safety Profiles of Swietenia Macrophylla Seeds Extract: A Review

BACKGROUND: Insulin resistance (IR) is known as the root cause of type 2 diabetes; hence, it is a substantial therapeutic target. Nowadays, studies have shifted the focus to natural ingredients that have been utilized as a traditional diabetes treatment, including Swietenia macrophylla. Accumulating evidence supports the hypoglycemic activities of S. macrophylla seeds extract, although its molecular mechanisms have yet to be well-established. AIM: This review focuses on the hypoglycemic molecular mechanisms of S. macrophylla seeds extract and its safety profiles. METHODS: An extensive search of the latest literature was conducted from four main databases (PubMed, Scopus, Science Direct, and Google Scholar) using several keywords: “swietenia macrophylla, seeds, and diabetes;” “swietenia macrophylla, seeds, and oxidative stress;” “swietenia macrophylla, seeds, and inflammation;” “swietenia macrophylla, seeds, and GLUT4;” and “swietenia macrophylla, seeds, and toxicities.” RESULTS: The hypoglycemic activities occur through modulating several pathways associated with IR and T2D pathogenesis. The seeds extract of S. macrophylla modulates oxidative stress by decreasing malondialdehyde (MDA), oxidized low-density lipoprotein, and thiobarbituric acid-reactive substances while increasing antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). Another propose mechanism is the modulating of the inflammatory pathway by attenuating nuclear factor kappa β, tumor necrosis factor α, inducible nitric oxide synthase, and cyclooxygenase 2. Some studies have shown that the extract can also control phosphatidylinositol-3-kinase/ Akt (PI3K/Akt) pathway by inducing glucose transporter 4, while suppressing phosphoenolpyruvate carboxykinase. Moreover, in vitro cytotoxicity and in vivo toxicity studies supported the safety profile of S. macrophylla seeds extract with the LD50 higher than 2000 mg/kg. CONCLUSION: The potential of S. macrophylla seeds as antidiabetic candidate is supported by many studies that have documented their non-toxic and hypoglycemic effects, which involve several molecular pathways.

Effect of postprandial triglycerides on DDT/ppDDE levels in subjects with varying degree of glucose intolerance

BACKGROUND

Organochlorine pesticides such as DDT as well as postprandial hypertriglyceridemia have been linked with insulin resistance and diabetes mellitus. The cardiometabolic risk of PPhTg could also be due to its potential to increase the serum levels of this highly lipophilic pesticide. We studied the effect of postprandial triglyceride responses to a standard oral fat challenge on the levels of DDT and its metabolites in subjects with varying degree of glucose intolerance METHODS: A standard fat challenge was performed in 60 subjects who were categorized as NGT, prediabetes, and NDDM based on an earlier OGTT. Fasting and postprandial levels of serum triglycerides, plasma DDT and its metabolites were estimated and compared in the 3 groups and their association with each other, and measures of glycemia and insulin resistance were also determined.

RESULTS

Peak Tg and TgAUC levels were significantly higher in NDDM group as compared to NGT and PD groups. TgAUC showed positive correlation with fasting plasma glucose (r=0.33, p=0.01), postprandial plasma glucose (r=0.39, p=0.002) and HOMA IR(r=0.63, p=0.001). ppDDE levels were found to be significantly higher in NDDM subjects compared with NGT group. ppDDE-AUC was significantly higher in the NDDM group compared with the other two study groups. Mean ppDDE levels also showed strong positive correlation with peak Tg (r=0.295 p=0.022), TgAUC (r=0.303 p=0.018), iPPTgAUC(r=0.57 p≤0.001) and iPPpeakTg(r=0.51 p≤0.001) as well as with FPG (r=0.269 p=0.038) PPPG (r=0.424 p=0.001) and HbA1c (r=0.321 p=0.012).

CONCLUSION

The findings of this study support the concept that the cardiometabolic risk associated with PPhTg may at least in part be related to the associated increase in serum levels of lipophilic OCPs like DDT.