Hypercholesterolemia is a major risk factor for the initiation and development of nonalcoholic fatty liver disease and atherosclerosis. The present study evaluated the hypocholesterolemic effect of virgin avocado oil (VAO) using urinary metabolomic method. Male Sprague-Dawley rats were fed high-cholesterol diet for four weeks to induce hypercholesterolemia. After confirming the establishment of hypercholesterolemia model, the VAO (450 and 900 mg·kg-1 ·day-1 ) and simvastatin (10 mg·kg-1 ·day-1 ) were given orally while maintaining the high-cholesterol diet for another four weeks. Assessment of urinary metabolomics using NMR revealed that VAO treatment could partially recover the metabolism dysfunction induced by hypercholesterolemia mainly via lipid, energy, amino acid, and gut microbiota metabolism.
In this study, we hypothesized that different strains of Lactobacillus can alleviate hyperlipidemia and liver steatosis via activation of 5' adenosine monophosphate-activated protein kinase (AMPK), an enzyme that is involved in cellular energy homeostasis, in aged rats. Male rats were fed with a high-fat diet (HFD) and injected with D-galactose daily over 12 weeks to induce aging. Treatments included (n = 6) (i) normal diet (ND), (ii) HFD, (iii) HFD-statin (lovastatin 2 mg/kg/day), (iv) HFD-Lactobacillus fermentum DR9 (10 log CFU/day), (v) HFD-Lactobacillus plantarum DR7 (10 log CFU/day), and (vi) HFD-Lactobacillus reuteri 8513d (10 log CFU/day). Rats administered with statin, DR9, and 8513d reduced serum total cholesterol levels after eight weeks (p < 0.05), while the administration of DR7 reduced serum triglycerides level after 12 weeks (p < 0.05) as compared to the HFD control. A more prominent effect was observed from the administration of DR7, where positive effects were observed, ranging from hepatic gene expressions to liver histology as compared to the control (p < 0.05); downregulation of hepatic lipid synthesis and β-oxidation gene stearoyl-CoA desaturase 1 (SCD1), upregulation of hepatic sterol excretion genes of ATP-binding cassette subfamily G member 5 and 8 (ABCG5 and ABCG8), lesser degree of liver steatosis, and upregulation of hepatic energy metabolisms genes AMPKα1 and AMPKα2. Taken altogether, this study illustrated that the administration of selected Lactobacillus strains led to improved lipid profiles via activation of energy and lipid metabolisms, suggesting the potentials of Lactobacillus as a promising natural intervention for alleviation of cardiovascular and liver diseases.