Curcumin, a potential inhibitor of up-regulation of TNF-alpha and IL-6 induced by palmitate in 3T3-L1 adipocytes through NF-kappaB and JNK pathway.
OBJECTIVE
To investigate the attenuating effect of curcumin, an anti-inflammatory compound derived from dietary spice turmeric (Curcuma longa) on the pro-inflammatory insulin-resistant state in 3T3-L1 adipocytes.


METHODS
Glucose uptake rate was determined with the [3H] 2-deoxyglucose uptake method. Expressions of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured by quantitative RT-PCR analysis and ELISA. Nuclear transcription factor kappaB p65 (NF-kappa p65) and mitogen-activated protein kinase (MAPKs) were detected by Western blot assay.


RESULTS
The basal glucose uptake was not altered, and curcumin increased the insulin-stimulated glucose uptake in 3T3-L1 cells. Curcumin suppressed the transcription and secretion of TNF-alpha and IL-6 induced by palmitate in a concentration-dependent manner. Palmitate induced nuclear translocation of NF-kappaB. The activities of Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase1/2 (ERK1/2) and p38MAPK decreased in the presence of curcumin. Moreover, pretreatment with SP600125 (inhibitor of JNK) instead of PD98059 or SB203580 (inhibitor of ERK1/2 or p38MAPK, respectively) decreased the up-regulation of TNF-alpha induced by palmitate.


CONCLUSIONS
Curcumin reverses palmitate-induced insulin resistance state in 3T3-L1 adipocytes through the NF-kappaB and JNK pathway.
Wang
Shao-Ling
SL
Department of Nutrition and Food Hygiene, Harbin Medical University, No.157 Baojian Road, Harbin 150081, Heilongjiang, China.
Li
Ying
Y
Wen
Ying
Y
Chen
Yan-Feng
YF
Na
Li-Xin
LX
Li
Song-Tao
ST
Sun
Chang-Hao
CH
D041721:3T3-L1 Cells; D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D003474:Curcumin / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D010168:Palmitates / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D000873:Anthracenes; D000894:Anti-Inflammatory Agents, Non-Steroidal; D007328:Insulin; D015850:Interleukin-6; D016328:NF-kappa B; D010168:Palmitates; D047428:Protein Kinase Inhibitors; D014409:Tumor Necrosis Factor-alpha; C432165:pyrazolanthrone; D048031:JNK Mitogen-Activated Protein Kinases; D003474:Curcumin; D005947:Glucose