Nutr Res Pract.  2015 Feb;9(1):30-36. 10.4162/nrp.2015.9.1.30.

The effects of black garlic (Allium satvium) extracts on lipid metabolism in rats fed a high fat diet

• Ha AW
• Ying T
• Kim WK

• KMID: 2313806
• DOI: http://doi.org/10.4162/nrp.2015.9.1.30

Abstract

BACKGROUD/OBEJECTIVES: The mechanism of how black garlic effects lipid metabolism remains unsolved. Therefore, the objectives of this study were to determine the effects of black garlic on lipid profiles and the expression of related genes in rats fed a high fat diet.
MATERIALS/METHODS
Thirty-two male Sqrague-Dawley rats aged 4 weeks were randomly divided into four groups (n=8) and fed the following diets for 5 weeks: normal food diet, (NF); a high-fat diet (HF); and a high-fat diet + 0.5% or 1.5% black garlic extract (HFBG0.5 or HFBG1.5). Body weights and blood biochemical parameters, including lipid profiles, and expressions of genes related to lipid metabolism were determined.
RESULTS
Significant differences were observed in the final weights between the HFBG1.5 and HF groups. All blood biochemical parameters measured in the HFBG1.5 group showed significantly lower values than those in the HF group. Significant improvements of the plasama lipid profiles as well as fecal excretions of total lipids and triglyceride (TG) were also observed in the HFBG1.5 group, when compared to the HF diet group. There were significant differences in the levels of mRNA of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PDH) in the HFBG1.5 group compared to the HF group. In addition, the hepatic expression of (HMG-CoA) reductase and Acyl-CoA cholesterol acyltransferase (ACAT) mRNA was also significantly lower than the HF group.
CONCLUSIONS
Consumption of black garlic extract lowers SREBP-1C mRNA expression, which causes downregulation of lipid and cholestrol metahbolism. As a result, the blood levels of total lipids, TG, and cholesterol were decreased.

Keyword

Black garlic; high-fat diet; lipid metabolism; SREBP-1C

MeSH Terms

Acetyl-CoA Carboxylase
Animals
Body Weight
Cholesterol
Diet
Diet, High-Fat*
Down-Regulation
Garlic*
Glucosephosphate Dehydrogenase
Humans
Lipid Metabolism*
Male
Oxidoreductases
Rats*
RNA, Messenger
Sterol O-Acyltransferase
Sterol Regulatory Element Binding Protein 1
Triglycerides
Weights and Measures
Acetyl-CoA Carboxylase
Cholesterol
Glucosephosphate Dehydrogenase
Oxidoreductases
RNA, Messenger
Sterol O-Acyltransferase
Sterol Regulatory Element Binding Protein 1

Figure

• 

  Fig. 1 Effect of black garlic extracts on mRNA expression of transcription factor and enzymes related to fat synthesis in liver of rats. Total RNA was isolated using TRI-reagenet and cDNA was synthesized using 3 µg of total RNA with SuperScript II reverse transcriptase. Realtime PCR was performed using SYBR green and standard procedures to assess the mRNA expression of primer in liver samples obtained from each group. An Applied Biosystem StepOne softwere v2.1 was used. Each bar represents the mean ± SE of three independent experiments. Different letters above each bar indicate significant differences among groups at α = 0.05 as determined by Duncan's multiple range test. ACC; Acetyl-CoA carboxylase, FAS; Fatty acid synthase, G6PDH; Glucose-6-phosphate dehydrogenase, SREBP-1C; Sterol regulatory element binding protein

• 

  Fig. 2 Effect of black garlic extracts on mRNA expression of CPT1 in liver of rats. Total RNA was isolated using TRI-reagenet and cDNA was synthesized using 3 µg of total RNA with SuperScript II reverse transcriptase. Realtime PCR was performed using SYBR green and standard procedures to assess the mRNA expression of primer in liver samples obtained from each group. An Applied Biosystem StepOne softwere v2.1 was used. Each bar represents the mean ± SE of three independent experiments. Different letters above each bar indicate significant differences among groups at α = 0.05 as determined by Duncan's multiple range test. CPT1; Carnitine palmitoyltransferase-1

• 

  Fig. 3 Effect of black garlic extracts on mRNA expression of protein related to cholesterol synthesis in liver of rats. Total RNA was isolated using TRI-reagenet and cDNA was synthesized using 3 µg of total RNA with SuperScript II reverse transcriptase. Realtime PCR was performed using SYBR green and standard procedures to assess the mRNA expression of primer in liver samples obtained from each group. An Applied Biosystem StepOne softwere v2.1 was used. Each bar represents the mean ± SE of three independent experiments. Different letters above each bar indicate significant differences among groups at α = 0.05 as determined by Duncan's multiple range tests. ACAT; Acyl-CoA cholesterol acyltransferase, HMG-CoA; Hydroxy-3-methylglutaryl coenzyme A

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