Curcumin Prevents High Fat Diet Induced Insulin Resistance and Obesity via Attenuating Lipogenesis in Liver and Inflammatory Pathway in Adipocytes

Abstract

BackgroundMechanisms underlying the attenuation of body weight gain and insulin resistance in response to high fat diet (HFD) by the curry compound curcumin need to be further explored. Although the attenuation of the inflammatory pathway is an accepted mechanism, a recent study suggested that curcumin stimulates Wnt signaling pathway and hence suppresses adipogenic differentiation. This is in contrast with the known repressive effect of curcumin on Wnt signaling in other cell lineages.Methodology and Principal FindingsWe conducted the examination on low fat diet, or HFD fed C57BL/6J mice with or without curcumin intervention for 28 weeks. Curcumin significantly attenuated the effect of HFD on glucose disposal, body weight/fat gain, as well as the development of insulin resistance. No stimulatory effect on Wnt activation was observed in the mature fat tissue. In addition, curcumin did not stimulate Wnt signaling in vitro in primary rat adipocytes. Furthermore, curcumin inhibited lipogenic gene expression in the liver and blocked the effects of HFD on macrophage infiltration and the inflammatory pathway in the adipose tissue.Conclusions and SignificanceWe conclude that the beneficial effect of curcumin during HFD consumption is mediated by attenuating lipogenic gene expression in the liver and the inflammatory response in the adipose tissue, in the absence of stimulation of Wnt signaling in mature adipocytes.

Specific Soluble Oligomers of Amyloid-β Peptide Undergo Replication and Form Non-fibrillar Aggregates in Interfacial Environments

“…It is important to point out that upon seeding with 20% seeds a significant reduction in lag times was observed in our previous report (1). The immunoblots recorded during the lag phase (24,48, and 72 h) showed the presence of a substantial amount of LFAOs in the seeded samples that was clearly absent in the control, suggesting that LFAOs had undergone replication during this time period. More importantly, the immunoblots also seem to indicate that the LFAO seeds are able to induce the formation of the 80 -110-kDa oligomers at the expense of 56 -70-kDa species observed within the unseeded LFAOs.…”

“…1A). The presence of NEFA was quantified using a free fatty acid assay kit (BioVision Inc., Milpitas, CA) as shown previously (24). Such examination indicated only a negligible amount (Ͻ0.1%) of NEFA present in these fractions containing isolated LFAOs (supplemental Fig.…”

Dietary factors, epigenetic modifications and obesity outcomes: Progresses and perspectives

“…In HFD-fed rats, the beneficial effect of curcumin is mediated by attenuating lipogenic gene expression in the liver and the inflammatory response in the adipose tissue (Shao et al, 2012). However, although curcumin is able to modulate histone deacetylases and acetyltransferases, DNA methyltransferase I, and miRNAs (Reuter et al, 2011), until now no studies have analyzed the involvement of curcumininduced epigenetic mechanisms in obesity models.…”

The Pleiotropic Effects of Curcumin.

“…In diabetes/Metabolic syndrome:-In mice models fed with high fat diet (HFD), curcumin has been found to reduce action of this diet on weight gain and improved insulin sensitivity [17] .Rise in levels of fasting plasma insulin induced by HFD was found to be decreased by curcumin. [17] Similarly a randomized control trial was conducted on subjects with metabolic syndrome who had a weight loss of <2% even after lifestyle modification and change in diet given for a period of 30 days and the subjects had a mean weight loss of around 1.88% ,a BMI reduction of 2.10%, a reduction in percentage fat of 0.70%.…”

“…[17] Similarly a randomized control trial was conducted on subjects with metabolic syndrome who had a weight loss of <2% even after lifestyle modification and change in diet given for a period of 30 days and the subjects had a mean weight loss of around 1.88% ,a BMI reduction of 2.10%, a reduction in percentage fat of 0.70%. [18] In this trial for 2751 the next 30 days the study group received Curcuma longa extract 800mg/dose/die (95% curcumin) with phosphotidylserine which is mixed with piperine 8mg/dose/die and the control group received phosphotidylserine 400mg/dose/die.…”