Endocrine Abstracts

Background: Adipose tissue dysfunction occurring in obesity leads to a low grade chronic inflammatory state. Fat tissue from obese individuals has a high infiltration rate of macrophages contributing to the development of obesity-related inflammation. At the cellular level, inflammation can be triggered by the activation (phosphorylation) of NF-κB as well as JNK. On the other hand, palmitic acid (PA) is a saturated fatty acid found elevated in plasma from obese subjects and shows pro-inflammatory activities in different cell types. Interestingly, people living in the Andean High Plateau in Northern Chile use the plant Lampaya medicinalis Phil. (Verbenaceae), known as Lampaya, against inflammatory diseases (rheumatism, arthritis and joint pain). The aim of this study was to evaluate the effect of a hydroalcoholic extract of Lampaya (HEL) against PA- induced inflammation in cultures of human macrophages.

Methods: Macrophages of the cell line THP-1 were incubated for 18 h in the following conditions: i) Control, ii) 0.1 μg/ml HEL, iii) 10 μg/ml HEL, iv) 0.2 mM PA, v) 0.1 μg/ml HEL +0.2 mM PA, vi) 10 μg/ml HEL +0.2 mM PA. Cell viability was determined by Tripan blue exclusion and phosphorylation of JNK and NF-κB was evaluated by Western blot.

Results: 0.1 and 10 μg/ml HEL did not affect cell viability compared to the control condition. PA-treated cells showed a 40% reduction in cell viability compared to control. Interestingly, when macrophages were treated with PA plus 0.1 μg/ml or 10 μg/ml HEL viability was restored to the control condition. On the other hand, a 40% increase in NF-κB phosphorylation was found in PA-treated macrophages compared to vehicle-treated cells. JNK phosphorylation was comparable between all experimental conditions assessed. In macrophages co-treated with HEL and PA, NF-κB phosphorylation was comparable to the control condition.

Conclusions: HEL overcomes PA-induced reduction in cell viability as well as the increase in NF-κB activation in THP-1 macrophages. These findings might support the traditional use of the plant for treating pathologies with an inflammatory component, such as the metabolic diseases associated with obesity.