Abstract
Objectives
High consumption of red meat can lead to cardiovascular disease. L-carnitine is rich in red meat can be metabolized by gut microbiota and hepatic enzyme to produce trimethylamine N-oxide (TMAO), which is the risk factor for cardiovascular disease. Garlic is a traditional food, exhibiting a medicinal effect against many diseases as well as garlic essential oil (GEO) possess anti-oxidation, anti-inflammation, and anti-hyperlipidemic effects to prevent cardiovascular disease. The purpose of this study is to investigate the protective effects of GEO on cardiovascular disease as well as explore the mechanism via modulation of gut microbiota composition and ameliorating lipid profiles.
Methods
GEO was extracted by steam distillation and its chemical constituents were analyzed by gas chromatography. The eight-week-old female apoE−/− mice were randomly divided into 5 groups: (1) chow diet, (2) 1.3% carnitine in water-fed group (negative control), (3) 1.3% carnitine + GEO (25 mg/kg bw), (4) 1.3% carnitine + GEO (50 mg/kg bw), and (5) 1.3% carnitine + 1% 3,3-dimethyl-1-butanol in water-fed (positive control). The mice were gavaged with GEO or soybean oil daily after 15 weeks the mice were sacrificed. The whole aorta was collected for observing the aortic plaque formation via oil red staining. The serum cholesterol, triglyceride, HDL, AST, and ALT were measured by an automatic blood analyzer. The bacterial metabolite trimethylamine (TMA) and TMAO were examined by using LC-MS. Illumina Miseq platform was used for 16S rDNA sequencing to analyze the feces microbiota composition.
Results
GEO significantly reduced the atherosclerotic lesion area in aorta compared to the carnitine-fed group (P < 0.01) and the effect is better than positive control. The serum HDL was improved by GEO (P < 0.01), but no change in serum total cholesterol level. The principal coordinate analysis of feces microbial composition revealed the differences in the gut microbiota composition. The carnitine and GEO shaped the feces microbiota alpha diversity. However, there are no significant findings in bacterial metabolites. Thus, the mechanistic effect of GEO against cardiovascular disease is mainly through the modulation of serum lipidomic.
Conclusions
GEO can serve as a functional food to prevent cardiovascular disease risk from high intake of red meat.
Funding Sources
MOST 108-2321-B-002 -035.