KR20030016191A - Aqueous Ethanolic Extract of the Skin of Onion for Decreasing or Maintaining Body Weight and a Method for Preparing the Same - Google Patents

Abstract

PURPOSE: A process of preparing an onion skin extract capable of maintaining or reducing a body weight by suppressing fat absorption using quercetin as flavonoid contained richly in the skin of onion is provided. Therefore, the extract is effective for treatment of overweight or obesity. CONSTITUTION: The skin of onion is ground and extracted 5 to 50 times with 10 to 95% ethanol. The extract is centrifuged at 5,000 to 20,000rpm, filtered with a filter paper having a hole size of 0.5μm and subjected to ultrafiltration with a 30 to 200 kDa ultrafiltration membrane. Thereafter, the filtrate is concentrated with a reverse osmosis with a salt rejection rate of 45 to 100% or under reduced pressure. The concentrate with an ethanol content of 10 to 30% is spray-dried with hot air at 170 to 250deg.C or concentrated.

Description

Aqueous Ethanolic Extract of the Skin of Onion for Decreasing or Maintaining Body Weight and a Method for Preparing the Same}

The present invention relates to onion peel extract for weight loss or weight maintenance. More specifically, the present invention relates to an onion peel extract containing quercetin as an active ingredient, which is prepared by extracting the onion peel with water-soluble ethanol and purified from the extract by non-heat treatment.

A brief look at the fat absorption process shows that the fats that can directly affect obesity are not individually absorbed. Fat is converted into a hydrophilic environment with the help of other secretions in order to have efficiency in transport and absorption in the intestinal mobile environment, which is insoluble in water. For example, fats esterified with fatty acids of high molecular weight, such as triglycerides, phospholipids, and cholesterol, are broken down with the help of lipolytic enzymes secreted from the pancreas and bile acids secreted from the gallbladder, which is linked to obesity. This is a recent interest. Just before the shift of the barrier, fat changes in the small intestine in the form of micelles, and even in this emulsion, each fat is distributed according to the degree of hydrophilicity. Phospholipids and bile acids form the shell of the emulsion, and triglycerides are located in the middle. Lipase acts on this micelle and is broken down and absorbed into the body. Therefore, it is possible to suppress fat absorption by inhibiting lipase. It was also confirmed that the fat left undecomposed during this process was excreted through the large intestine.

In other words, the small intestine is the first body organ where food is actually absorbed through the stomach and can ultimately inhibit obesity by inhibiting the fat absorption function of the organ. In particular, in relation to fat metabolism, total or partial fat (triglyceride or cholesterol) can be selectively reduced at the intestine level. The drug Orlistat (Generic; Swiss Roche) has been developed and clinically prescribed using this principle, but its side effects such as bloating and fatty stools are problematic.

Flavonoids are present in large quantities in all kinds of vegetables, fruits and teas, making up the largest collection of polyphenols, and more than 5,000 species have been found. Based on the ring structure of C6-C3-C6, various hydroxyl groups (hydroxyl; -OH) are attached and have functionalities depending on the number and position of the hydroxyl groups. A study that flavonoids influence fat absorption process Results are being reported recently. Flavonoids with high molecular weight have been reported to form strong complexes with various types of enzymes and proteins in different body organs and to precipitate at the same time. These complexes appeared to inhibit the activity of the enzyme by forming a strong bond with a number of hydroxyl groups attached to the ring structure or enzyme.

An object of the present invention is to provide a method for producing a composition that can reduce weight or maintain weight by inhibiting fat absorption by using quercetin, which is a flavonoid, which is contained in a large amount in onion peel.

These and other objects can be achieved by the present invention described below.

1 is a process diagram sequentially showing the manufacturing process of extracts of weight loss or weight maintaining onion peel containing quercetin from the onion peel according to the present invention.

Figure 2 is a graph showing the effect on the absorption of triglycerides of onion peel extract according to the present invention.

Onion peel extract for weight loss or weight maintenance according to the present invention is purified by a non-heat treatment membrane separation process from the water-soluble ethanol extract of onion peel, and contains the quercetin represented by the formula (1) as an active ingredient.

[Formula 1]

Method for producing an onion peel extract according to the present invention (1) the extraction step of grinding the onion peel and continuous extraction by adding 10 to 95% ethanol at 5 to 30 times (w / v) of the ground at room temperature; (2) The supernatant obtained by centrifuging the ethanol extract at 5,000 rpm to 20,000 rpm with a centrifugal separator was fine filtered with 0.1 to 0.5 μm of filtration holes, and then ultrafiltered with an ultrafiltration membrane having a fractional molecular weight of 30 kDa to 200 kDa. Filtration step to obtain; (3) concentrating the filtrate using a reverse osmosis process using a salt rejection 45% to 100% reverse osmosis membrane or concentrating using a reduced pressure concentrator; And (4) spray-drying the concentrated solution having a ethanol content of 10% to 30% using hot air at 170 ° C to 250 ° C, or concentrating the ethanol to be completely volatilized, and then freeze drying, hot air drying, reduced pressure drying, and the like. Drying step of drying by a drying method; This is done including.

In the extraction step (1), the onion skin is pulverized and 10% to 95% ethanol is added at 5 to 30 times (w / v), preferably 20 times (w / v) of 10 kg of the pulverized product at room temperature. The extraction step is extracted three times, or preferably using a continuous extractor.

The filtration step of (2) is a step to facilitate post-treatment by removing impurities present in the ethanol extracted extract first. The centrifugation process is performed to remove solid impurities that may be introduced during extraction, using a continuous centrifuge at 5,000 rpm to 20,000 rpm, preferably 10,000 rpm. The supernatant obtained here is microfiltered with 0.1-0.5 μm, preferably 0.2 μm, filtration pores, to remove microparticles that will seriously cause membrane contamination during ultrafiltration. In addition, the ultrafiltration process is a filtration process for ultrafiltration with an ultrafiltration membrane having a fractional molecular weight of 30 kDa to 200 kDa, preferably 50 kDa, to remove macromolecules such as polysaccharides and proteins and to obtain a high-purity filtrate.

The concentration step of (3) is a step of reducing the capacity by concentrating the filtrate obtained in the filtration step of (2) to facilitate the post-treatment. Concentration is a step of concentration by reverse osmosis using a reverse osmosis membrane with a salt rejection rate of 45% to 100%, preferably 95%, or concentration under vacuum at 30 to 60 to reduce the amount of ethanol as solvent used for extraction. So that the ethanol content is 10% to 30% to facilitate the operation during the post-treatment.

In the drying step (4), the concentrated liquid may be spray-dried using a hot air of 170 ° C. to 250 ° C., preferably 200 ° C., to prepare a powder having a purity of 4 7 times higher than the purity of quercetin present in the onion peel.

In another aspect, the present invention provides an onion peel extract prepared by the above method.

The ethanol extract containing quercetin according to the present invention can be obtained by stopping at an intermediate stage in the method for preparing the anti-obesity quercetin according to the present invention as described above.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited to Examples.

Example 1 Preparation of Water-soluble Ethanol Extract of Onion Peel from Quercetin Containing Weight Loss or Weight Maintenance from Onion Peel

200 kg of ethanol was added to 10 kg of the onion peel pulverized product, and the extract was centrifuged at 10,000 rpm using a continuous centrifuge to obtain a supernatant.

Example 2 Preparation of Water-Soluble Ethanol Extract of Onion Peel from Quercetin

The supernatant obtained in Example 1 was ultrafiltered with 0.2 μm of filtration holes, and the filtrate was ultrafiltered with an ultrafiltration membrane having a fractional molecular weight of 50 kDa, or concentrated by reverse osmosis using a reverse osmosis membrane with a salt excretion rate of 95%. Or it concentrated using the vacuum concentrator at 50 degreeC.

Example 3 Drying of Extract for Weight Loss or Weight Maintenance from Onion Peel

The concentrated liquid obtained from Example 2 was spray dried using hot air at 200 ° C. to prepare a powder of onion peel extract.

Experimental Example 1 Analysis of Quercetin Content in Onion Peel and Production Process

The content of quercetin in the onion peel and the extracts of Examples 1, 2 and 3 was analyzed by high-performance liquid chromatography (product of Japan's Jasco Corporation; model name PU-980). Spectrophotometrically at 1 mL / min with an acetonitrile / water gradient (0 → 30 minutes, 20/80 → 50/50) on an Exterra RP18 column (125 μs, 5 μm, 4.6 × 150 mm; manufactured by Waters, USA) It was analyzed at a wavelength of 365 nm of a detector (manufactured by Jasco, Japan; model name UV-975), and the conditions are shown in Table 1 below.

Quercetin Content Analysis Condition in Onion Peel and Manufacturing Process Column XTerraTM RP185 μm (4.6 × 150mm) XTerraTM RP185 μm (3.9 × 20mm) Guard column Mobil phase Acetonitrile, water (pH 2.5 with trifluoacetic acid) Gradient 0 minutes 20% acetonitrile, 30 minutes 50% acetonitrile Flow rate 1.0 mL / min Temperature 30 ℃ Wavelength 365 nm

As a result, the quercetin content of onion peel was 13.4 mg / g dry weight, and the dried final extract content was 66.4 mg / g.

Next, after extracting the onion peel (5kg) with 60% ethanol (100L) for 2 hours, the concentration change and yield of the quercetin for each process during concentration shown in Figure 1 is shown in Table 2 below.

Quercetin content in each step fair density Weight or volume quercetin total amount (g) yield(%) smash 12mg / g 5000 g 60.0 100 extraction 205.6 mg / L 100L 20.5 34.3 Centrifugation 248.3 mg / L 70L 17.4 29.0 Precision filtration 253.3 mg / L 67L 17.0 28.3 Ultrafiltration 263.8 mg / L 62L 16.4 27.3 concentration 3621mg / L 2.5L 9.1 15.1 dry 66.4 mg / g 120 g 8.0 13.3

Experimental Example 2 Experimental Influence of Extracts Purified by Onion Peel on the Activity of Lipolytic Enzyme from Onion Peel

A pH-stat (Radiometer A / S, DK-2400 Copenhagen NV, Denmark) consisting of a PHM290 digital pH meter with XC161 Combined pH Electrode, SAM7 Sample Stand, PHM290 pH-Stat Controller, and T201 Temperature Sensor was analyzed. The emulsifier was prepared by dissolving 17.9 g of NaCl and 0.41 g of KH 2 PO 4 in a 1 L beaker, adding 400 mL of distilled water and 540 mL of glycerol and adding 6.0 g of arabic gum in small amounts while mixing with a magnetic mixer. Substrate emulsion was added 15mL of tributyrin (tributyrin) to the blender, 50mL of emulsifier was added, 235mL of distilled water was added and mixed for 20 seconds at the maximum speed. In order to determine the effect of onion peel extract, quercetin and olistat on lipolytic enzyme, 10.0mL of substrate solution (tracticyrin emulsion) was added to the reaction vessel, and 0.5mL of the measurement sample was added. When the pH was kept constant during mixing, pH-Stat was operated after adding 0.5 mL of lipolytic enzyme (pancreatic lipolytic enzyme; US Sigma; 100 U / mL). The reaction started within 1 minute and 0.05N NaOH was added until the pH was 7.00, and the lipolytic activity was calculated from the volume of NaOH which was entered between 3 and 8 minutes after the reaction was completed for 10 minutes.

[formula]

Lipase activity (U / L) = (mL / 8min-mL / 3min) × 0.05 (NaOH concentration) × 1 / 0.5 × 10 ^-3

The inhibition rate was calculated from the calculated lipase activity, and the results are shown in Table 3 below. The lipase inhibitory activity of the onion peel extract was about 1/1000 as compared to Olstat, and 10 times higher than that of quercetin.

Effect of Onion Peel Extract on Lipolytic Activity Inhibitor Concentration (ug / mL) 1 Inhibition Rate (%) ² IC50 (g / mL) ³ Onion Peel Extract 4.55 6.01 ± 0.01 ⁴ 53.70 45.46 47.15 ± 5.34 454.55 87.78 ± 0.92 Quercetin 4.55 6.66 ± 0.09 527.1 45.46 12.47 ± 4.10 454.55 44.03 ± 2.14 Olistat 0.010 22.82 ± 5.87 0.041 ± 0.004 0.090 69.29 ± 22.82 0.91 95.02 ± 0.00 ¹ Concentration of the sample in the reaction solution ² Inhibition rate (%) = 100-(lipase activity of the sample / lipase activity of the control) × 100 ³ Concentration of the sample inhibiting the reaction of the control by 50% ⁴ Mean value ± standard deviation

Experimental Example 3: Effect of Extracts Purified by Onion Peel on the Triglyceride Absorption of Rats

As shown in Table 4, the rats (Sprague Dawley rat, male, 5 weeks old, Korea Biolink Co., Ltd.) divided into four groups by the ingot method, the control group, onion peel extract administration group (50mg / kg body weight), quercetin administration group (3 mg / kg body weight), olistat administration group (0.1 mg / kg body weight). The dose of 3 mg / kg of the quercetin-administered group was determined to be the same amount of quercetin as the onion-shell extract based on the quercetin content of 66.4 mg / g of the onion-shell extract. Lipid emulsion was prepared by adding 80 mg of choline acid and 1 g of cholesteryl oleate to 6 mL of soybean oil, and then adding 6 mL of saline solution and homogenizing it with a tissue homogenizer. After 12 hours of fasting the rats, all groups received oral lipid emulsion at 7.5 mL / kg BW, followed by inhibitors for each group. Blood was collected from the ocular vein at 1 hour intervals for 4 hours after administration to separate plasma, and the triglyceride content was measured using a triglyceride kit (Sigma product) by the enzyme method. The results are shown in Table 5 below.

ingredient Control Onion group Quercetin Olistatt Lipid emulsion Soybean oil Soybean oil Soybean oil Soybean oil Onion Peel Extract - 50mg / kg BW - - Quercetin - - 3mg / kg BW - Olistat - - - 0.1mg / kg BW

As shown in Table 5 and Figure 2, onion peel extract 50mg / kg BW significantly reduced the triglycerides in the blood by administration of soybean oil emulsion at 3 hours and 4 hours after administration. In addition, the total triglyceride increase during 4 hours of soybean oil emulsion administration significantly reduced. This effect is the same as the result of the administration of quercetin 3mg / kg Bw. It is considered that the fat absorption inhibitory effect of the onion peel extract was caused by quercetin.

Effect of Onion Peel Extract on Triglyceride Absorption (△ Plasma TG, mg / dL) Group 1hr 2hr 3hr 4hr Total triglyceride increase Control 97.62 ± 47.82 270.94 ± 70.23 422.08 ± 107.87 ^a 421.64 ± 168.30 ^a 1001.46 ± 196.25 ^a Onion group 123.96 ± 21.62 233.87 ± 77.55 244.94 ± 75.63 ^b 256.34 ± 84.72 ^b 730.94 ± 187.81 ^b Quercetin 86.33 ± 41.81 245.84 ± 89.14 223.67 ± 82.97 ^b 175.18 ± 105.76 ^bc 643.44 ± 238.36 ^b Olistatt 72.42 ± 30.63 171.57 ± 83.38 101.22 ± 41.21 ^c 30.13 ± 52.63 ^c 360.26 ± 137.02 ^c Significance p <0.001 p <0.001 p <0.001 Each value represents mean ± SE (control; n = 6, onion group; n = 5, quercetin group; n = 6, olistat group, n = 6) Means with different letters (a, b, c) within a column are significantly different from each other at α = 0.05 as determined by Duncan's multiple range test (a> b> c)

Experimental Example 4 Effect of Long-term Administration of Onion Peel Extract on Weight Loss in Rats

The mice (ICR mice, females, 4 weeks old, manufactured by Daehan Biolink Co., Ltd., Korea) were preliminarily bred as solid feeds for 1 week to adjust to the environment, and then the control group (15% fat; 5% corn oil) by referring to the weight by the egg mass method. + 10% lard) and onion group (15% fat + 5% onion skin extract) were divided into 8 weeks. The contrast of the kennel was adjusted at 12 hour intervals, and the temperature was maintained at 22 ± 2 ℃ and the humidity was 50 ~ 60%. Water and diet were supplied without restriction. The dietary composition is shown in Table 4 below.

Diet ingredient Control group (g) Onion group (g) Casein 200 200 Cellulose 50 50 Choline bitartrate 2 2 Corn oil 50 50 Lard 100 100 Corn starch 350 300 Methionine 3 3 Mineral mixture 35 35 Sucrose 200 200 Vitamin mixture 10 10 Onion extract 50 BHT 0.003 0.003 Total 1000 1000

Dietary intake was measured twice a week at regular times to determine the average daily dietary intake per week. Body weight was also measured in the same order twice a week at regular times. On the last day of the experiment, the animals were anesthetized with ether, and blood was collected in heparin-treated test tubes, centrifuged at 2,000 rpm for 10 minutes, and plasma was used as analytical sample. Immediately after blood collection, liver and paramaterial adipose tissues were extracted and weighed. Plasma, liver and adipose tissue were stored at -70 ° C until analysis. Fecals were collected for 48 hours before sacrifice, dried, stored at -70 ° C, and freeze-dried. Plasma glucose was analyzed using a glucose kit (Sigma, Cat. No. 315-100) to which the glucose oxidase method was applied, and plasma cholesterol and triglyceride contents were measured using a kit by the enzyme method (Sigma). Extraction of cholesterol and triglycerides from liver samples was analyzed using a kit using a modified method of Folch et al. The dried and powdered stools were extracted with lipid by Soxhlet method, and the total fat content was measured by specific gravity method. All experimental results were expressed as mean and standard error, and statistical significance was analyzed by Student's t-test at α = 0.05 level using SAS program.

As a result, as shown in Table 7, there was no significant difference in dietary intake, weight gain was significantly reduced by 23%. As shown in Table 8, there was no significant difference in the weight of the liver, and the amount of subcutaneous fat decreased by 33%. As shown in Table 9 below, plasma triglyceride concentration was 21%, blood glucose concentration 19%, blood sugar level was significantly reduced by 16%.

Plasma albumin concentration refers to the balance of protein intake, plasma alkaline phosphatase activity refers to liver and bone abnormalities, and plasma creatinine concentration refers to abnormal protein metabolism. As shown in Table 10, the onion peel extract did not affect the metabolism of other tissues of the mice because there was no difference in these three items compared to the control group. Onion peel extract did not affect the weight of liver, triglyceride and cholesterol content as shown in Table 11, so it did not affect the fat content of blood by relatively short-term breeding for 8 weeks, but did not affect liver fat content. It was found that.

As shown in Table 12, the onion peel extract significantly increased the amount of feces excreted daily by 35% compared to the control group, increased the amount of fat in feces excreted daily by 64%, and the fat absorption amount was 22 % Significantly decreased. This demonstrates the increase in the amount of fat excretion expected from the results of Experimental Examples 2 and 3 that onion peel extract inhibited fat absorption by inhibiting lipolytic enzymes.

As discussed above, the water-soluble ethanol extract of onion peel suppressed weight gain by inhibiting fat absorption.

Effect of 8 Weeks of Onion Peel Extract on Body Weight and Dietary Intake in ICR Mice group Initial weight (g) Terminal weight (g) Weight change (g / wk) Dietary Intake (g / day) Control 22.73 ± 1.28 27.90 ± 2.62 0.69 ± 0.18 3.35 ± 0.45 Onion group 22.68 ± 1.30 26.94 ± 1.93 0.53 ± 0.15 ^** 3.79 ± 0.56 Five-week-old female ICR mice were kept on the experimental diet for 8wk.Each value represents mean ± SD of 7-8 mice. ^** p <0.01

Groups Liver (g / 100g BW) Parametrial adipose tissue (g / 100g BW) Fecal dry weight (g / day) Control 3.56 ± 0.24 1.99 ± 0.85 0.26 ± 0.06 Onion group 3.54 ± 0.27 1.32 ± 0.61 ^* 0.35 ± 0.11 Five-week-old female ICR mice were kept on the experimental diet for 8wk.Each value represents mean ± SD of 7-8 mice.Groups differ significantly p <0.05 by t-test

Effects of Onion Peel Extracts on Triglyceride, Cholesterol, and Glucose Concentrations in Plasma of ICR Mice Experimental group Triglycerides (mg / dl) Cholesterol (mg / dl) Glucose (mg / dl) Control 85.32 ± 19.02 153.43 ± 29.61 80.65 ± 25.95 Onion group 67.76 ± 5.43 ^* 124.42 ± 17.48 ^* 67.63 ± 11.67 ^* Five-week-old female ICR mice were kept on the experimental diet for 8wk.Each value represents mean ± SD of 7-8 mice.Groups differ significantly p <0.05 by t-test

Effect of Onion Peel Extract on Plasma Albumin, Alkaline Phosphatase, and Creatinine Group Albumin (g / dL) Alkaline phosphatase activity (U / L) Creatinine (mg / dL) Control 4.14 ± 0.71 32.38 ± 8.17 0.55 ± 0.10 Onion group 4.28 ± 0.36 38.70 ± 10.53 0.60 ± 0.09 Five-week-old female ICR mice were kept on the experimental diet for 8wk.Each value represents mean ± SD of 7-8 mice.

Effects of Onion Peel Extracts on Liver Weight, Triglycerides and Cholesterol Experimental group Liver weight (g / 100g BW) Triglycerides of the liver (mg / g) Cholesterol in the liver (mg / g) Control 3.56 ± 0.24 23.06 ± 3.72 4.31 ± 0.78 Onion group 3.54 ± 0.27 21.36 ± 7.89 4.23 ± 0.82 Five-week-old female ICR mice were kept on the experimental diet for 8wk.Each value represents mean ± SD of 7-8 mice

The amount of fecal excretion and fat absorption Group Fecal dry weight (g / day) Fat intake (g / day) Fecal fat (g / day) % of amount ingested Fat absorption (g / day) Control 0.263 ± 0.062 0.557 ± 0.152 0.011 ± 0.005 97.44 ± 1.39 0.546 ± 0.152 Onion group 0.354 ± 0.108 ^* 0.445 ± 0.181 0.018 ± 0.006 ^* 94.04 ± 2.47 ^** 0.427 ± 0.179 ^* Five-week-old female ICR mice were kept on the experimental diet for 8wk.Each value represents mean ± SD of 9-10 mice. ^* p <0.05, ^** p <0.01

Extract of onion peel according to the present invention is prepared by extracting the onion peel with water-soluble ethanol and purified by the non-heat treatment from the extract, it is excellent in weight loss or weight maintenance activity is effective in the treatment of overweight and obesity.

While the invention has been described in detail above with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the invention, and such modifications and variations fall within the scope of the appended claims. It is also natural.

Claims (3)

Onion peel extract, characterized in that it contains a quercetin represented by the formula (1) as an active ingredient. (1) an extraction step of grinding the onion peel and continuous extraction by adding 5 to 30 times (w / v) of 10% to 95% ethanol at room temperature at room temperature; (2) The supernatant obtained by centrifuging the water-soluble ethanol extract at 5,000 rpm to 20,000 rpm with a centrifugal separator was fine filtered with 0.1 to 0.5 μm of filter pores, and then ultrafiltered with an ultrafiltration membrane having a fractional molecular weight of 30 kDa to 200 kDa. Filtration step to obtain; (3) concentrating the filtrate using a reverse osmosis process using a salt rejection 45% to 100% reverse osmosis membrane or concentrating using a reduced pressure concentrator; And (4) The concentrated liquid pretreated to have an ethanol content of 10% to 30% by spray drying using hot air of 170 ° C to 250 ° C or concentrated to completely volatilize ethanol and then dried by freeze drying, hot air drying and vacuum drying Drying step; Onion peel extract manufacturing method characterized in that it comprises a. Onion peel extract prepared by the method of claim 2.