Ethanol extract of Pinus koraiensis leaves containing lambertianic acid exerts anti-obesity and hypolipidemic effects by activating adenosine monophosphate-activated protein kinase (AMPK)

Abstract

BackgroundIn this study, we investigated the anti-obesity and anti-hyperlipidemic mechanisms of lambertianic acid (LA) isolated from Pinus koraiensis leaves and the ethanol extract of Pinus koraiensis leaves (EPK), both in vitro and in vivo.MethodsDifferentiated 3T3L-1 cells were treated with EPK (25 or 50 μg/mL) or LA (200 μM) and analyzed by western blotting or RT-PCR. In vitro, lipid accumulation of adipocytes was observed using Oil-Red-O staining and triglyceride analysis. The contribution of AMPK to anti-obesity activity was assessed by siRNA-mediated AMPK knockdown. After AMPK silencing, expression of AMPK was observed by western blotting. To confirm the in vitro activity, an animal study was conducted by administering a normal diet, HFD, and EPK for 6 weeks. Obesity-related physiological parameters and protein levels were measured.ResultsLA induced the expression of p-AMPK and inhibited PPARγ, C/EBP α, adiponectin, FAS, SREBP-1, and HMGCR expression. EPK containing LA significantly decreased lipid accumulation and triglyceride levels in the differentiated 3 T3-L1 cells. EPK treatment suppressed the expression of adipogenic transcription factors, FABP, GPDH, and cholesterol-synthesis-related factors in the differentiated 3 T3-L1 cells. EPK increased the expression of p-AMPK. The effects of EPK were reversed on inhibiting AMPK by using AMPK siRNA and compound C. In vivo analysis showed that body weight gain, serum triglyceride, total cholesterol, LDL cholesterol and AI value in the EPK treatment group were lower than those in the HFD control group. EPK induced the expression of p-AMPK and inhibited PPARγ in liver and adipose tissue.ConclusionsOverall, the results suggest that EPK containing LA exerts significant anti-obesity and cholesterol-lowering effects by activating AMPK.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-016-1031-2) contains supplementary material, which is available to authorized users.

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“…thus, The utilization of AMPK or perhaps the regulation of downstream targets may provide potential therapeutic targets in the treatment of prostate cancer41. Of note, in line with our results, the compound C directly inhibition of the phosphorylation of AMPK itself have been reported in several other studies424344. Concerning an additional feedback role, the effects of compound C on AMPK signaling could be more complicated then we thought.…”

Apoptotic effect of lambertianic acid through AMPK/FOXM1 signaling in MDA‐MB231 breast cancer cells

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Anti-Cancer Effect of Lambertianic Acid by Inhibiting the AR in LNCaP Cells

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