Method for improving lipid metabolism and short-chain fatty acid of high-fat fed rats by using wheat bran

Abstract

The invention discloses a method for improving lipid metabolism and short-chain fatty acid of high-fat fed rats by using wheat bran, which comprises the following steps of: randomly grouping 24 SPF (specific pathogen free)-level male SD (Sprague Dawley) rats, feeding, introducing water, replacing mouse cages, and measuring and recording body weight and food intake; after feeding for 13 weeks, fasting food but not forbidding water for 12 hours, weighing the body weight, measuring the body length, and calculating the Le's index; anesthetizing, dissecting and separating the liver, the kidney, the spleen and the cecum, reserving adipose tissues, weighing and recording, and calculating organ coefficients and adipose indexes; measuring the contents of TC, TG, HDL-C and LDL-C in the serum; the content of short-chain fatty acid in the rat cecum content is detected through dehydration embedding, paraffin section preparation, HE dyeing and observation under a microscope. According to the method disclosed by the invention, the wheat bran can improve body quality and blood fat level rise caused by high-fat diet and liver fatty degeneration caused by the high-fat diet, can reverse intestinal short-chain fatty acid level reduction caused by the high-fat diet, and plays an important role in preventing the occurrence of dyslipidemia and obesity.

Description

Technical Field

[0001] The invention relates to the field of improvement of lipid metabolism and short-chain fatty acids in high-fat-fed rats, and in particular to a method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats by using wheat bran. Background Art

[0002] In recent years, obesity and related metabolic diseases have become increasingly serious public health problems worldwide. Obesity is an important risk factor for a variety of metabolic diseases, including hypertension, type 2 diabetes, cancer, dyslipidemia, and cardiovascular and cerebrovascular diseases. Obesity is a complex chronic disease with complex etiology, but lifestyle changes, including dietary behavior, play a vital role in obesity management. Therefore, finding natural and effective dietary intervention methods has become a hot topic in current research.

[0003] Wheat bran, as a byproduct of wheat processing, is rich in dietary fiber, B vitamins, phytochemicals and other beneficial ingredients, especially dietary fiber. Dietary fiber can not only regulate blood sugar and blood lipid levels, increase satiety, and promote intestinal peristalsis, but can also be fermented by intestinal microorganisms to produce short-chain fatty acids (SCFAs), such as acetic acid, propionic acid, butyric acid and valeric acid. These short-chain fatty acids can not only provide energy for intestinal cells, but also regulate intestinal immune function and inflammatory response, and play an important role in maintaining intestinal health and preventing metabolic diseases.

[0004] However, due to factors such as the hardness, texture and taste of wheat bran, its application in food is limited. It is often used in industries such as winemaking, vinegar making and feed, resulting in the under-utilization of wheat bran, a valuable resource. This paper explores the trend of changes in body weight, organ weight, serum and liver tissue pathological morphology of high-fat fed rats after wheat bran intervention, in order to gain a deeper understanding of the effects of wheat bran on high-fat fed rats, aiming to provide a reference for the treatment and prevention of obesity and metabolic health. Summary of the invention

[0005] In view of this, the present invention provides a method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats by using wheat bran comprises the following steps:

[0008] Step 1: 24 SPF male SD rats were randomly divided into 4 groups, 6 rats in each group, fed with diet, with normal water intake, and cages were changed regularly. The body weight and food intake of the rats were measured and recorded every week;

[0009] Step 2: After 13 weeks of continuous feeding, fast but not water for 12 hours, weigh body weight, measure body length, and calculate Lee's index;

[0010] Step 3: After the rats were anesthetized, the liver, kidneys, spleen and cecum were dissected and separated, the adipose tissue was collected, weighed and recorded, and the organ coefficient and fat index were calculated;

[0011] Step 4: Use an automatic biochemical analyzer to measure the levels of serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol;

[0012] Step 5: The liver tissue was dehydrated, embedded, and paraffin sections were prepared. HE staining was performed and the pathological changes of liver tissue were observed under a microscope.

[0013] Step 6: Use gas chromatography-mass spectrometry to detect the content of short-chain fatty acids in the rat cecal contents.

[0014] Preferably, in step 1, four groups are divided into a normal control group, a high-fat diet group, a low-dose wheat bran group and a high-dose wheat bran group.

[0015] Preferably, in step 1, the normal control group is fed with ordinary feed, the high-fat diet group is fed with a high-fat feed containing 5% wheat dietary fiber, the low-dose wheat bran group is fed with a high-fat feed containing 10% wheat dietary fiber, and the high-dose group is fed with a high-fat feed containing 15% wheat dietary fiber.

[0016] Preferably, in step 1, feed and water are replaced every other day.

[0017] Preferably, in step 2, the body length measured is the distance from the nose tip to the anus of the rat.

[0018] Preferably, in step 2, Lee's index = [body weight (g)] 1 / 3 ÷ body length (cm) × 1000.

[0019] Preferably, in step 3, the adipose tissue refers to perirenal fat and peritesticular fat.

[0020] Preferably, in step 3, organ coefficient (%) = organ mass × 100 / rat body weight; fat index (%) = fat wet weight (g) / body weight (g) × 100.

[0021] Compared with the prior art, the present invention has achieved the following technical effects:

[0022] Through the method of the present invention, wheat bran can improve the body weight, increased blood lipid levels and liver fatty degeneration caused by a high-fat diet, and can reverse the reduction of intestinal short-chain fatty acid levels caused by a high-fat diet, which plays an important role in preventing the occurrence of dyslipidemia and obesity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 HE staining (×100) of the liver of each group of rats in the method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats with wheat bran of the present invention;

[0024] a Normal control group, b high-fat diet group, c low-dose wheat bran group, d high-dose wheat bran group;

[0025] Figure 2 A diagram showing butyrate levels of the method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats by wheat bran of the present invention;

[0026] Figure 3 This is a graph of valeric acid levels in the method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1-3 As shown, the present invention discloses a method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats by using wheat bran, comprising the following steps:

[0029] Step 1: 24 SPF male SD rats were randomly divided into 4 groups: normal control group, high-fat diet group, low-dose wheat bran group and high-dose wheat bran group, with 6 rats in each group. The normal control group was fed with ordinary feed, the high-fat diet group was fed with high-fat feed containing 5% wheat dietary fiber, the low-dose wheat bran group was fed with high-fat feed containing 10% wheat dietary fiber, and the high-dose group was fed with high-fat feed containing 15% wheat dietary fiber. Water was drawn normally, feed and water were changed every other day, mouse cages were changed regularly, and rat body weight and food intake were measured and recorded every week.

[0030] Step 2: After 13 weeks of continuous feeding, the rats were fasted but not watered for 12 hours, weighed, and the distance from the nose tip to the anus was measured to calculate the Lee's index;

[0031] Lee's index = [body weight (g)] 1 / 3 ÷ body length (cm) × 1000;

[0032] Step 3: After the rats are anesthetized, the liver, kidneys, spleen and cecum are dissected and separated, and the adipose tissue, i.e., perirenal fat and peritesticular fat, is obtained and weighed and recorded, and the organ coefficient and fat index are calculated;

[0033] Organ coefficient (%) = organ mass × 100 / rat body weight; fat index (%) = fat wet weight (g) / body weight (g) × 100;

[0034] Step 4: Use an automatic biochemical analyzer to measure the levels of serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol;

[0035] Step 5: The liver tissue was dehydrated, embedded, and paraffin sections were prepared. HE staining was performed and the pathological changes of liver tissue were observed under a microscope.

[0036] Step 6: Use gas chromatography-mass spectrometry to detect the content of short-chain fatty acids in the rat cecal contents.

[0037] Embodiment 1:

[0038] Experimental Animals:

[0039] 24 SPF male SD rats, weighing 210-270 g, were purchased from the Animal Experiment Center of Xinjiang Medical University, with the license for experimental animals: SYXK (Xin) 2023-0004. All animals were raised in an SPF barrier environment at Xinjiang Medical University, with a temperature of 20-24 °C, a relative humidity of 40%-70%, 12h light and dark alternation, and ordinary feed adaptive feeding for 1 week for the experiment. The experimental feed was purchased from Beijing Keao Xieli Feed Co., Ltd., with the feed production license number: SCXK (Beijing) 2019-0003. The animal welfare and ethical requirements were strictly observed throughout the animal experiment (approval number: IACUC-20210309-09).

[0040] Main reagents and instruments:

[0041] Kits for total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were purchased from Shenzhen Mindray Bio-Medical Electronics Co., Ltd. BS-240VET fully automatic biochemical analyzer (Shenzhen Mindray Medical), low-speed centrifuge (Shanghai Fitchaer Analytical Instrument Co., Ltd.), -20°C freezer (Aucma Co., Ltd.), Haier DW-86L490J ultra-low temperature refrigerator -80°C.

[0042] Statistical analysis:

[0043] Excel 2010 software was used to organize the data, and SPSS24.0 was used for statistical analysis. All measurement data were expressed as mean ± standard deviation. For data that obeyed the normal distribution and satisfied the variance homogeneity test, one-way analysis of variance was used. Otherwise, non-parametric tests were used. P < 0.05 was considered statistically significant.

[0044] result:

[0045] Effects on body weight, body length, and Lee's index of rats

[0046] There was no significant difference in body weight among the rats in each group before the experiment (P>0.05). After 13 weeks of feeding, compared with the normal control group, the body weight, body length and Lee's index of the rats in the high-fat diet group increased (all P<0.05); the body length of the rats in the low-dose and high-dose wheat bran groups increased (all P<0.05).

[0047] Compared with the high-fat diet group, the Lee's index of rats in the low- and high-dose wheat bran groups was reduced, and the body weight of rats in the high-dose group was reduced (all P<0.05), as shown in Table 1.

[0048] Table 1: Effects of wheat bran on body weight, body length, and Lee's index of rats (x±s)

[0049]

[0050]

[0051] Note: #Compared with normal control group, P<0.05; *Compared with high-fat diet group, P<0.05

[0052] Effects on organ weights in rats

[0053] Compared with the normal control group, the weights of liver, kidney, peritesticular fat, and perirenal fat in the high-fat diet group were increased (all P<0.05).

[0054] Compared with the high-fat diet group, the liver, kidney, and peritesticular fat weights of rats in the low- and high-dose wheat bran groups were reduced, and the perirenal fat weight of rats in the low-dose group was reduced (all P<0.05), as shown in Table 2.

[0055] Table 2: Effects of wheat bran on organ weights of rats (x±s, g)

[0056]

[0057] Note: #Compared with normal control group, P<0.05; *Compared with high-fat diet group, P<0.05

[0058] Effects on organ coefficients and fat index in rats

[0059] Compared with the normal control group, the cecal coefficient of rats in the high-fat diet group was decreased, and the peritesticular fat index and perirenal fat index were increased (all P<0.05).

[0060] Compared with the high-fat diet group, the peritesticular fat index and perirenal fat index of rats in the low- and high-dose wheat bran groups were reduced, and the cecum coefficient of rats in the high-dose group was increased (all P<0.05), as shown in Table 3.

[0061] Table 3: Effects of wheat bran on organ coefficients and fat index in rats (x±s, %)

[0062]

[0063] Note: #Compared with normal control group, P<0.05; *Compared with high-fat diet group, P<0.05

[0064] Effects on serum parameters of rats

[0065] Compared with the normal control group, the serum TC and LDL-C levels of rats in the high-fat diet group and the low- and high-dose wheat bran groups were increased (all P<0.05); the HDL-C level in the high-fat diet group was decreased (P<0.05).

[0066] Compared with the high-fat diet group, the serum TC level of rats in the low-dose wheat bran group was decreased, and the HDL-C level was increased (all P<0.05); the serum TG level of rats in the high-dose wheat bran group was decreased, and the HDL-C level was increased (all P<0.05), as shown in Table 4.

[0067] Table 4: Effects of wheat bran on serum parameters of rats (x±s)

[0068]

[0069]

[0070] Note: #Compared with normal control group, P<0.05; *Compared with high-fat diet group, P<0.05

[0071] Effects on the pathological morphology of rat liver tissue

[0072] The liver tissue structure of rats in the normal control group was intact, the hepatocytes were normal in morphology, the cells were uniform in size, tightly arranged, and the cell outlines were clear. In the liver tissue of the high-fat diet group, a large number of hepatocytes showed fatty degeneration, round vacuoles of different sizes were seen in the cytoplasm, the nuclei were offset, the cells were loosely arranged, the outlines were blurred, and the accumulation of lipid droplets and fat deformation were clearly visible.

[0073] Compared with the high-fat diet group, the degree of liver fatty degeneration in the low- and high-dose wheat bran groups was significantly improved, mainly manifested by a significant decrease in lipid droplets, narrowing of intercellular spaces, clear cell contours, neat cell structures, and reduced abnormalities. This indicates that wheat bran can improve liver fatty degeneration caused by a high-fat diet.

[0074] Effects of succinate on the levels of short-chain fatty acids in rat cecum contents

[0075] Compared with the normal control group, the levels of butyrate and valeric acid in the cecal contents of rats in the high-fat diet group were decreased, while the levels of butyrate and valeric acid in the rats in the low- and high-dose wheat bran groups were restored to varying degrees.

[0076] Wheat bran can improve the decreased levels of butyrate and valeric acid in cecal contents caused by a high-fat diet, and plays an important role in preventing the occurrence of dyslipidemia and obesity.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats by using wheat bran, characterized in that: The following steps are involved: Step 1: 24 SPF male SD rats were randomly divided into 4 groups, 6 rats in each group, fed with diet, with normal water intake, and cages were changed regularly. The body weight and food intake of the rats were measured and recorded every week; Step 2: After 13 weeks of continuous feeding, fast but not water for 12 hours, weigh body weight, measure body length, and calculate Lee's index; Step 3: After the rats were anesthetized, the liver, kidneys, spleen and cecum were dissected and separated, the adipose tissue was collected, weighed and recorded, and the organ coefficient and fat index were calculated; Step 4: Use an automatic biochemical analyzer to measure the levels of serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol; Step 5: The liver tissue was dehydrated, embedded, and paraffin sections were prepared. HE staining was performed and the pathological changes of liver tissue were observed under a microscope. Step 6: Use gas chromatography-mass spectrometry to detect the content of short-chain fatty acids in the rat cecal contents.

2. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In the step 1, the mice were divided into four groups: a normal control group, a high-fat diet group, a low-dose wheat bran group, and a high-dose wheat bran group.

3. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In step 1, the normal control group is fed with ordinary feed, the high-fat diet group is fed with a high-fat feed containing 5% wheat dietary fiber, the low-dose wheat bran group is fed with a high-fat feed containing 10% wheat dietary fiber, and the high-dose group is fed with a high-fat feed containing 15% wheat dietary fiber.

4. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In step 1, feed and water are replaced every other day.

5. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In step 2, the body length is measured from the nose tip to the anus of the rat.

6. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In step 2, Lee's index = [body weight (g)] 1 / 3 ÷ body length (cm) × 1000.

7. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In step 3, the adipose tissue refers to perirenal fat and peritesticular fat.

8. The method for improving lipid metabolism and short-chain fatty acids in high-fat-fed rats using wheat bran according to claim 1, characterized in that: In step 3, organ coefficient (%) = organ mass × 100 / rat body weight; fat index (%) = fat wet weight (g) / body weight (g) × 100.

Images