Obesity represents one of the most serious global health issues. Environmental and genetic factors play an important role in the increase in obesity that is affecting the whole of mankind on a large scale. Among these, diet-induced obesity has become one of the most critical medical problems in the world(Reference Ogden, Carroll and Curtin1). Obesity is defined medically as a state of increased body weight, more specifically adipose tissue, of sufficient magnitude to produce adverse health consequences(Reference Spiegelman and Flier2, Reference Metges3). The excessive fat accumulation in adipose tissue, liver and other organs strongly predisposes obese individuals to the development of metabolic changes that increase overall morbidity risk. Obesity is associated with insulin resistance(Reference Kahn and Flier4), a state of low-grade chronic inflammation(Reference Stienstra, Duval and Müller5) and the metabolic syndrome. The metabolic syndrome is related to higher circulating levels of inflammatory markers, many of which enhance tumour growth(Reference Pischon, Nöthlings and Boeing6). Clearly, prevention and management of obesity are relevant to health promotion.
The predominant obesity-causing factor is energy imbalance. While pharmaceutical treatments for obesity have been extensively researched, only a few drugs have been approved for long-term use in significantly obese patients by the Food and Drug Administration. However, they have adverse effects including gastrointestinal discomfort, flatulence and diarrhoea(Reference Heck, Yanovski and Calis7). In addition to prescription drugs, nutritional supplements for weight loss are popular in the over-the-counter market. Although such treatments are widely used, few have been proved to be safe and effective(Reference Pittler and Ernst8). Hence, it is necessary to find more effective and safe treatments through the inhibition of digestion and absorption of dietary fat which is the target for obesity treatment.
A number of studies have documented that dietary fibres provide a variety of human health benefits. β-Glucans are non-digestible polysaccharides that are widely found in nature in sources such as cereal grains, including oats and barley, as well as in yeast, bacteria, algae and mushrooms(Reference Delaney, Nicolosi and Wilson9–Reference McIntosh, Stone and Stanisich11). Cereals are the most common source of dietary β-glucans and are linear glucose polymers of three to four glucose residues of (1 → 4)-β-d linkages and separated by β-(1 → 3) linkages, and exhibit only partial solubility in water(Reference Delaney, Nicolosi and Wilson9). Yeast β-glucan is a branched polysaccharide consisting of a backbone chain of (1 → 3)-β-d-glucopyranosyl units, along which are randomly dispersed side chains of d-glucopyranosyl units attached by β-(1 → 6) linkages, and is insoluble in water(Reference Babícek, Cechová and Simon10). The cholesterol-lowering effect of cereal or yeast has been reported(Reference Reyna-Villasmil, Bermúdez-Pirela and Mengual-Moreno12–Reference Nicolosi, Bell and Bistrian14), and the mechanisms of action of glucans in lowering plasma cholesterol have been wildly studied. Specifically, Marlett et al. (Reference Marlett, Hosig and Vollendorf15) have shown that induction of bile acid excretion is one possible mechanism. The increased viscosity of gastrointestinal content by β-glucans is also a key factor for the decrease in cholesterol level. Viscosity depends on the solubility of β-glucan and its molecular weight(Reference Asp, Mattsson and Onning16). Raw oat bran, because of the low solubility of β-glucans, has no significant effect on cholesterol level(Reference Würsch and Pi-Sunyer17). However, commercial oat bran has already been heated and forms viscous solutions and has a significant cholesterol-lowering effect(Reference de Groot, Luyken and Pikaar18). The solubility of fibre leads to a change in viscosity, which has a powerful impact on plasma cholesterol(Reference Carr, Gallaher and Yang19).
Salecan is a novel water-soluble glucan produced by Agrobacterium sp. ZX09. It is an extracellular polysaccharide consisting of the following repeating unit: → 3)-β-d-Glcp-(1 → 3)-(β-d-Glcp-(1 → 3)-β-d-Glcp-(1 → 3))3-α-d-Glcp-(1 → 3)-α-d-Glcp-(1 → . The production and chemical properties of Salecan have been reported in a previous study(Reference Xiu, Kong and Zhou20). The average molecular weight of Salecan was estimated to be about 2 × 106Da from a calibration curve of standard dextrans obtained by gel filtration on Sepharose CL-4B(Reference Xiu, Kong and Zhou20). Salecan solutions are highly viscous even at low polymer concentrations. Acute and subchronic studies have demonstrated that administration of Salecan induced no toxicity(Reference Xiu, Zhan and Zhou21) and Salecan has excellent rheological properties and could be utilised in the food industry(Reference Xiu, Zhou and Zhu22). The aim of the present study was to investigate the effects of Salecan on diet-induced obesity and fat accumulation in mice.
Materials and methods
Preparation of Salecan
The preparation of Salecan has been described previously(Reference Xiu, Kong and Zhou20). Briefly, the strain ZX09 used in the present study was isolated from a soil sample from the ocean coast of Shandong, China. Cultures were maintained on Htm agar consisting of 1 g NaH2PO4, 3 g KNO3, 0·07 g CaCl2, 0·2 g MgCl2, 0·0125 g FeSO4.7H2O, 0·003 g MnSO4, 0·0075 g ZnCl2, 20 g sucrose, 9 g agar and 1000 ml water, pH 7·2. A colony of the strain ZX09 was inoculated into a 250 ml flask containing 50 ml medium consisting of 2 % sucrose and mineral salt solution. The inoculated preparation was incubated at 28°C on a rotary shaker at 220 rpm for 24 h. A 0·5 ml portion was transferred to a 250 ml flask containing 50 ml fermentation medium. Fermentation was performed on a rotary shaker at 220 rpm for 48 h. The culture broth was diluted more than three times with deionised water and centrifuged at 12 000 g for 30 min to separate cells from the supernatant. The supernatant was added to two volumes of 95 % ethanol. Recovery of Salecan was expressed in terms of weight after ethanol precipitation collected by centrifugation at 6000 g for 15 min and dried under reduced pressure.
Animals and diets
Female C57BL/6 mice, 6 weeks old, were used in the present study. Animals were maintained under controlled environmental conditions of temperature (22 ± 2°C) and 12 h light–12 h dark cycles with lights on from 07.00 to 19.00 hours, and with free access to food and water. All animal care and use procedures were in accordance with the guidelines of the Institutional Animal Care and Use Committee at Nanjing University of Science & Technology. Mice were divided into four groups (n 8): low-fat diet (LFD), high-fat diet (HFD) only, HFD with 2 % Salecan (HF-2 %S) and HFD with 5 % Salecan (HF-5 %S) for 6 weeks. Preparation of the experimental diets was according to the method described previously with some modifications(Reference Bae, Lee and Kim23). Salecan has the composition of 77 % sugar, 6 % protein and 13·8 kJ/g (3·3 kcal/g) energy(Reference Xiu, Kong and Zhou20). By adding the different amounts of casein, maize starch, lard oil and cellulose to the last three different diets (HFD, HF-2 %S and HF-5 %S), the total energy and the final proportion of major macronutrients are the same across the experimental diets. The LFD provided a total energy of 16·3 kJ/g (3·9 kcal/g), i.e. 12 % from fat, 67 % from carbohydrate and 21 % from protein, and the HFD, HF-2 %S and HF-5 %S provided a total energy of 23·4 kJ/g (5·6 kcal/g), i.e. 64 % from fat, 21 % from carbohydrate and 15 % from protein. The compositions of each diet are shown in Table 1. The amounts of food and water in the feeding containers were measured every day at 09.00 hours. Food and water intake were expressed as g/d per mouse.
Table 1 Composition of the experimental diets
AIN, American Institute of Nutrition.
LFD, low-fat diet; HFD, high-fat diet; HF-2 %S, high-fat diet with 2 % Salecan; HF-5 %S, high-fat diet with 5 % Salecan.
* AIN-93M mineral mixture (ICN).
† AIN-93VX vitamin mixture (ICN).
Body composition measurements
Body weights were measured for each animal in duplicate just before body composition measurements using a standard scale, and the mean body weight was used for analysis. The Bruker Minispec (Bruker Optics), which employs NMR technology to estimate the body composition of the animals, was used to assess body composition. The percentage of fat mass of each animal was calculated at each time point as fat mass divided by body weight.
Glucose tolerance tests
Intraperitoneal glucose tolerance tests were performed after 4 weeks of treatment. After 14 h of fasting, mice were injected intraperitoneally with glucose (2 g/kg body weight). Oral glucose tolerance tests were performed after 6 weeks of treatment. Mice fasted for 18 h were given glucose orally by intragastric tube to provide 1 g glucose/kg body weight. Blood glucose was determined before and after treatment using a One Touch Blood Glucose Meter (AW063-436-01A; LifeScan Inc.) with 3 μl of the whole blood obtained by tail bleed. AUC values were calculated and normalised to baseline to measure glucose tolerance.
Sampling and biochemical assays
Faeces obtained during 24 h were collected and weighed, and lipids were extracted with chloroform–methanol (2:1, v/v) according to the method described previously(Reference Folch, Lees and Stanley24). After 6 weeks of dietary treatment, mice were anaesthetised at 09.00 hours (i.e. non-fasting) and blood was collected from a carotid artery. Liver and parametrial white adipose tissues were collected, weighed and immediately frozen in liquid N2 for further analysis. Serum was then separated by centrifugation at 3000 g for 15 min and stored at − 80°C until analysis. Extraction of lipids from the liver was according to the method described previously(Reference Haug and Høstmark25). Briefly, hepatic tissue was homogenised (10 %, w/v) in isopropanol for 20 s. To extract TAG and cholesterol, the homogenate was kept at 4°C for 2 d, and then centrifuged at 1000 g for 10 min. Aliquots of the supernatants were analysed for TAG and cholesterol. Concentrations of serum TAG, total cholesterol (TC), HDL-cholesterol, hepatic TAG, TC and faecal TAG were determined using the Triglyceride Test Kit (Beijing BHKT Clinical Reagent) by an enzymatic method.
Histopathology
Liver and parametrial adipose samples were fixed in 10 % formalin–saline, embedded in paraffin, and then sectioned. Sections (5 μm) were stained with haematoxylin and eosin dye for histopathological examination by light microscopy.
Emulsion preparation
Preparation of emulsions was according to the method described previously with some modifications(Reference Pasquier, Armand and Guillon26). Briefly, Salecan was dissolved in buffer solution (50 mm-Tris–HCl, 150 mm-NaCl, pH 7·5) under stirring at room temperature. The emulsions were prepared by mixing 4 μl olive oil into 10 μl buffer solution (with 0·3, 0·6 % Salecan or without Salecan), and a fixed volume of fresh murine bile samples (obtained just after killing) was added to a final volume of 16 μl. The tubes were capped and shaken at 1000 strokes/min for 20 min at 37°C. The samples were examined and photographed immediately after preparing the emulsion under bright field illumination on a photomicroscope. The procedure was duplicated by taking a second sample from the same emulsion.
Statistical analysis
All data are expressed as means with their standard errors. Statistical analysis was performed using SPSS 13.0 software (SPSS Inc.), and differences between groups were analysed by one-way ANOVA followed by Tukey's post hoc test. Differences between means were considered statistically significant at P <0·05.
Results
Decreased body weight and fat in mice fed with Salecan
Compared with the LFD group, mice fed on the HFD (HFD group) gained more body mass during the feeding periods, and reached a higher body weight at the end of the experiment (P< 0·05). In the HF-2 %S and HF-5 %S groups, body weight was reduced by 11 and 18 % compared with the HFD group, respectively (Fig. 1(a)). No significant differences were found between the HFD, HF-2 %S and HF-5 %S groups for lean mass (Fig. 1(b)). Both HF-2 %S and HF-5 %S groups markedly decreased body fat mass (28 and 43 %, respectively) and the percentage of fat mass (21 and 31 %, respectively) compared with the HFD group (Fig. 1(c), (d)).
Fig. 1 Effects of Salecan on body weight and body composition in high-fat diet-fed mice. (a) Body weight, (b) lean mass and (C) fat mass were determined at weeks 0, 2, 4 and 6. (d) The percentage of fat mass of each animal was calculated at each time point as fat mass divided by body weight. Values are means of eight animals, with standard errors represented by vertical bars. * Mean values were significantly different from those of the low-fat diet (LFD, 
) group (P <0·05). † Mean values were significantly different from those of the high-fat diet (HFD, 
) group (P <0·05). 
, High-fat diet with 2 % Salecan; 
, high-fat diet with 5 % Salecan.
Feeding Salecan lowered lipid levels in the liver and adipose tissue
As shown in Table 2, the 5 % Salecan treatment (HF-5 %S group) decreased liver weight by 22 %, and decreased parametrial white adipose tissue weight by 56 %. Histological analysis of hepatocytes revealed that the HFD group had severe fat anomalies with a large area of hepatocytes taken over by fat vacuoles compared with the LFD group (Fig. 2(a), (b)). There were some lipid vacuoles in the HF-2 %S group, but the granularity and quantity of lipid vacuoles were much less compared with the HFD group (Fig. 2(c)). There were only a few small lipid vacuoles in the HF-5 %S group, and the appearance was very similar to that of the LFD group (Fig. 2(d)). The adipocyte diameter in parametrial adipose tissue was much larger in the HFD group than in the LFD group (Fig. 2(e), (f)). Haematoxylin–eosin staining showed an apparent reduction of adipocyte size in the Salecan treatment groups (Fig. 2(g), (h)). The lipid profiles of plasma and liver are shown in Table 3. Mice in the HFD group had higher TAG and cholesterol compared with the LFD group. The elevated lipid profiles in HFD-fed mice were alleviated by the Salecan treatment. There were differences between the HF-2 %S and HFD groups in serum and hepatic TAG levels (P< 0·05). Compared with the HFD group, the HF-5 %S group showed lower serum TAG by 52 %, TC by 18 %, HDL-cholesterol by 19 %, and lower hepatic TAG and TC by 56 and 22 %, respectively. Serum and hepatic TAG levels in the HF-5 %S group were almost similar to those in the LFD group.
Table 2 Effect of Salecan on liver and adipose tissue weight (Mean values with their standard errors; n 8)
LFD, low-fat diet; HFD, high-fat diet; HF-2 %S, HFD with 2 % Salecan; HF-5 %S, HFD with 5 % Salecan.
* Mean values were significantly different from those of the LFD group (P <0·05).
† Mean values were significantly different from those of the HFD group (P <0·05).
Fig. 2 Effects of Salecan on liver fat accumulation and adipocyte size. (a–d) Hepatic pathological variations of the experimental animals. (e–h) Adipocyte size variations of the experimental animals. Mice (6 weeks old) were provided a low-fat diet (LFD) or high-fat diets (HFD) containing 0, 2 or 5 % Salecan for 6 weeks, and liver and parametrial adipose were removed for histological examination. For each group, six mice were examined and sixty images were taken. The image shown here for each group was chosen randomly from the sixty images taken from this group. Original magnification, 400 × . HF-2 %S, high-fat diet with 2 % Salecan; HF-5 %S, high-fat diet with 5 % Salecan.
Table 3 Effect of Salecan on serum and hepatic lipid composition (Mean values with their standard errors; n 8)
TC, total cholesterol; HDL-C, HDL-cholesterol; LFD, low-fat diet; HFD, high-fat diet; HF-2 %S, HFD with 2 % Salecan; HF-5 %S, HFD with 5 % Salecan.
* Mean values were significantly different from those of the LFD group (P <0·05).
† Mean values were significantly different from those of the HFD group (P <0·05).
‡ Mean values were significantly different from those of the HF-2 %S group (P <0·05).
Diet and glucose tolerance
HFD-induced obesity was associated with alterations in liver and adipose lipid metabolism, displaying impaired glucose tolerance in HFD mice. Intraperitoneal glucose tolerance tests were performed on mice after 4 weeks of dietary treatment. The concentrations of blood glucose in LFD, HFD, HF-2 %S and HF-5 %S mice reached a maximum at 30 min after the intraperitoneal administration of glucose, and then declined to the basal value. The HFD group significantly impaired the glucose response during 2 h glucose tolerance tests compared with the LFD group (Fig. 3(a)). The rise and fall of blood glucose in the HF-5 %S group was similar to that in the LFD group (Fig. 3(a)), suggesting that Salecan could improve the glucose tolerance of mice fed the HFD. Compared with the HFD group, the AUC for glucose was lower in the HF-5 %S group (P< 0·05), and tended to be lower in the HF-2 %S group (Fig. 3(b)). Additionally, an oral glucose tolerance test was conducted after 6 weeks of food consumption. Glucose concentrations 30 min after the oral administration of glucose in the HFD group were higher than those in the LFD group (P< 0·05; Fig. 3(c)). Salecan markedly and dose-dependently reduced the blood glucose level (Fig. 3(c)), with a 9 and 26 % reduction of glucose AUC in the HF-2 %S and HF-5 %S groups compared with the HFD group (Fig. 3(d)).
Fig. 3 Effects of Salecan on glucose tolerance in high-fat diet (HFD)-fed mice. (a) Intraperitoneal glucose tolerance tests were performed after 4 weeks of food consumption and (b) AUC values were calculated and normalised to baseline. Mice were intraperitoneally given 2 g glucose/kg body weight after 14 h of food deprivation. (c) Oral glucose tolerance tests were performed after 6 weeks of food consumption and (d) AUC values were calculated and normalised to baseline. Mice were intragastrically given 1 g glucose/kg body weight after 18 h of food deprivation. Values are means of five to six animals, with standard errors represented by vertical bars. * Mean values were significantly different from those of the low-fat diet (LFD, ) group (P <0·05). † Mean values were significantly different from those of the HFD () group (P <0·05). , HFD with 2 % Salecan (HF-2 %S); , HFD with 5 % Salecan (HF-5 %S).
Mice fed on Salecan increased fat excretion in the faeces
We further investigated whether Salecan could change food consumption. After having free access to the diets and water for 6 weeks, there were no obvious differences among the HFD, HF-2 %S and HF-5 %S groups in mean diet and water intake (Fig. 4(a), (b)). Next, we measured faeces weight and composition. As shown in Table 4, all groups fed on the HFD showed a lower faeces weight compared with the LFD group. Mice fed the HFD containing 2 and 5 % Salecan (HF-2 %S and HF-5 %S groups) increased faecal mass (23 and 51 %) and had a higher TAG level in the faeces compared with the HFD group (27 and 69 %), implying that Salecan could disturb fat digestion and absorption.
Fig. 4 Effect of Salecan on food and water intake. (a) Food intake and (b) water intake are expressed as g/d per mouse. Values are means of eight animals, with standard errors represented by vertical bars. * Mean values were significantly different from those of the low-fat diet (LFD) group (P <0·05). † Mean values were significantly different from those of the high-fat diet (HFD) group (P <0·05). HF-2 %S, high-fat diet with 2 % Salecan; HF-5 %S, HFD with 5 % Salecan.
Table 4 Effect of Salecan on fat excretion in the faeces of mice fed a high-fat diet (HFD) (Mean values with their standard errors; n 6–7)
LFD, low-fat diet; HF-2 %S, HFD with 2 % Salecan; HF-5 %S, HFD with 5 % Salecan.
* Mean values were significantly different from those of the LFD group (P <0·05).
† Mean values were significantly different from those of the HFD group (P <0·05).
‡ Mean values were significantly different from those of the HF-2 %S group (P <0·05).
Salecan altered bile acid-promoted emulsification of fat in vitro
To clarify the effect of Salecan on fat digestion, an in vitro test of emulsification of fat by bile acids in the presence of Salecan was performed. Emulsion droplet size was determined by light microscopy. Without Salecan, the droplets were densely packed, small in mean diameter and distributed over a narrower size range (Fig. 5(a)). Fig. 5(b) shows large oil droplets produced by 0·3 % Salecan dispersed among small oil droplets. Fig. 5(c) shows the micrographs of 0·6 % Salecan, showing much larger emulsion droplet size compared with the 0 % Salecan group. The size of the emulsified droplets was increased by raising the concentration of Salecan. These data suggested that Salecan disturbed the bile acid-promoted emulsification of fat.
Fig. 5 Effects of Salecan on lipid emulsification. Photomicrographs of emulsion prepared with (a) 0 %, (b) 0·3 % or (c) 0·6 % Salecan under bright field illumination. Each experiment was performed at least three times. For each group, thirty images were taken. The image shown here for each group was chosen randomly from the thirty images taken from this group. Original magnification, 100 × . Scale bar = 100 μm.
Discussion
Bacterial extracellular polysaccharides (such as xanthan or gellan gum) can be easily produced and applied as thickeners and stabilisers in foods as food additives. Salecan, a novel soluble extracellular β-glucan, produced by a marine bacterium ZX09, contains a large amount of β-1,3-d-glucosidic linkages as the main backbone structure, together with a small proportion of α-1,3-d-glucosidic linkages(Reference Xiu, Kong and Zhou20). The differences between the β-glucan linkages and the chemical structure are significant with regard to solubility and overall biological activity(Reference Schmid, Stone and McDougall27, Reference Šandula, Kogan and Kačuráková28). β-Glucans are not digestible due to a lack of hydrolase in both humans and mice, and are constituents of dietary fibre. NSP are major components of dietary fibre, which resist human small-intestinal digestion. Glucans, by their very nature, are components of fibre. The actual direct energy dilution by NSP is generally very small in human diets as only 20–30 g/d are consumed. Then, it is well recognised that dietary fibres provide less energy as a substitute for nutrients in diets, promote satiation and prolong satiety(Reference Lairon29). Soluble dietary fibre increases stool volume and stool water content(Reference Burkitt30, Reference Burkitt31), and can increase the viscosity of gut contents, carrying undigested food into the colon. A short-term feeding study of Salecan in mice showed no toxic effects(Reference Xiu, Zhan and Zhou21). Salecan, as a novel soluble dietary fibre, has a potential for promoting good heath and preventing obesity-related diseases.
Many studies have been carried out to investigate the effects of soluble fibres on body weight in mice and human subjects. Oat bran β-glucan at a concentration of 10 % lowers body weight(Reference Sanchez, Muguerza and Moulay32). However, a meta-analysis that combined the results of eleven randomised controlled trials found that guar gum supplements were not effective in reducing body weight(Reference Pittler and Ernst33). In the present study, the HF-2 %S and HF-5 %S groups displayed a lower body weight than the HFD group. No significant differences were found between the HFD, HF-2 %S and HF-5 %S groups for lean mass. Fat mass and the percentage of fat mass were lower in the HF-2 %S and HF-5 %S groups compared with the HFD group. Previous studies showed that viscous soluble dietary fibres reduced lipid emulsification(Reference Pasquier, Armand and Castelain34). Similarly, we found that Salecan could disturb bile acid-promoted emulsification and increase the size of emulsified fat droplets. The size and composition of the emulsified droplets alter the binding and the hydrolytic activity of pancreatic lipase(Reference Borel, Armand and Ythier35, Reference Armand, Borel and Ythier36). Then, TAG excretion was significantly increased in the faeces of mice by Salecan supplementation. It has been suggested that Salecan reduced the rate of fat digestion and absorption by reducing lipid emulsification.
Liver and adipose tissue weights and adipose size were increased in HFD-fed mice(Reference Nozaki, Fujita and Yoneda37, Reference Madsen, Guerre-Millo and Flindt38). A previous study has reported that barley β-glucan significantly reduced liver weight, but not adipose tissue weight(Reference Choi, Kim and Jung39). Another previous study has found that barley significantly reduced adipose tissue in mice fed a HFD(Reference Yokoyama and Shao40). According to the present results, Salecan treatment significantly reduced both liver and adipose tissue weights. Oats were first found to have a cholesterol-lowering effect and the active component was identified as β-glucan(Reference Kerckhoffs, Brouns and Hornstra41). Oats reduced both serum TC and LDL-C compared with the control(Reference Kerckhoffs, Hornstra and Mensink42, Reference Theuwissen and Mensink43), and barley has also been shown to have a similar effect(Reference Davy, Davy and Ho44, Reference Behall, Scholfield and Hallfrisch45). However, oat and barley β-glucans do not improve TAG(Reference Colhoun, Betteridge and Durrington46). Similarly to the previous studies, we also observed that the intake of Salecan might help mice maintain lower serum levels of TC and HDL-cholesterol compared with the HFD group; moreover, we also found that serum TAG levels decreased by the Salecan treatment. Consequently, HFD-induced impaired glucose tolerance was improved by feeding Salecan, indicating a potential application in treating the metabolic syndrome. Increasing the intake of fibre in one's diet may lead to socially unacceptable symptoms such as bloating, cramping and flatulence(Reference Anderson and Gustafson47, Reference Eastwood and Passmore48). These side effects are the result of colonic fermentation of soluble fibre leading to the production of gases and volatile SCFA(Reference Maki, Davidson and Torri49). However, most studies have reported no complaints of gastrointestinal distress after a high intake of dietary fibre(Reference Delaney, Carlson and Zheng50, Reference Story, Anderson and Chen51). Further studies will be needed to see whether Salecan has any gastrointestinal side effects.
In summary, consumption of Salecan suppressed weight gain, decreased body fat content and markedly improved glucose tolerance in mice fed the HFD. Furthermore, feeding Salecan lowered liver and parametrial adipose tissue weights, and protected against liver and adipocyte fat accumulation. The present findings suggest that foods containing Salecan could be useful in treating diet-induced obesity.
Acknowledgements
This study was supported by the National Science Foundation of China (30730030). The authors' contributions are as follows: Y. Z. performed the experiments, analysed the data, prepared the images and drafted the manuscript; L. X. performed the experiments, analysed the data and edited the manuscript; W. P. performed the experiments and analysed the data; T. W. prepared the images; P. C. analysed the data; B. Z. analysed the data; J. Z. conceived and designed the research, edited and revised the manuscript, and approved the final version of the manuscript. The authors declare that they have no conflict of interest.
