Moringa Leaves Prevent Hepatic Lipid Accumulation and Inflammation in Guinea Pigs by Reducing the Expression of Genes Involved in Lipid Metabolism

Abstract

To investigate the mechanisms by which Moringa oleifera leaves (ML) modulate hepatic lipids, guinea pigs were allocated to either control (0% ML), 10% Low Moringa (LM) or 15% High Moringa (HM) diets with 0.25% dietary cholesterol to induce hepatic steatosis. After 6 weeks, guinea pigs were sacrificed and liver and plasma were collected to determine plasma lipids, hepatic lipids, cytokines and the expression of genes involved in hepatic cholesterol (CH) and triglyceride (TG) metabolism. There were no differences in plasma lipids among groups. A dose-response effect of ML was observed in hepatic lipids (CH and TG) with the lowest concentrations in the HM group (p < 0.001), consistent with histological evaluation of lipid droplets. Hepatic gene expression of diglyceride acyltransferase-2 and peroxisome proliferator activated receptor-γ, as well as protein concentrations interleukin (IL)-1β and interferon-γ, were lowest in the HM group (p < 0.005). Hepatic gene expression of cluster of differentiation-68 and sterol regulatory element binding protein-1c were 60% lower in both the LM and HM groups compared to controls (p < 0.01). This study demonstrates that ML may prevent hepatic steatosis by affecting gene expression related to hepatic lipids synthesis resulting in lower concentrations of cholesterol and triglycerides and reduced inflammation in the liver.

Keywords: Moringa oleifera; gene expression; guinea pigs; hepatic steatosis; inflammation; lipid accumulation.

Figure 1

(A) Lecithin cholesterol acyltransferase (LCAT) and (B) Cholesterol ester transfer protein (CETP) activities of guinea pigs fed control, Low Moringa (LM; 10 g/100 g) and High Moringa (HM; 15 g/100 g) diets. * indicates significantly different from control at p < 0.01. RFU, Reference Units.

Figure 2

Histological images of hematoxylin and eosin (H&E) (200×) stained hepatic tissue for (A) Control, (B) Low Moringa (LM; 10%), and (C) High Moringa (HM; 15%). Scale bar = 100 μm.

Figure 3

Hepatic gene expression of LDL receptor (LDL-R), cluster of differentiation 68 (CD68), SREBP1, DGAT2 and PPARγ of guinea pigs fed control (black bars), Low Moringa (LM; 10%, gray bars) or High Moringa (HM; 15%, white bars). Different superscripts, a and b denote significantly different at p < 0.05.