Effects of soy components on blood and liver lipids in rats fed high-cholesterol diets

Effect of Lactic Acid Fermentation on Legume Protein Properties, a Review

Legume proteins have a promising future in the food industry due to their nutritional, environmental, and economic benefits. However, their application is still limited due to the presence of antinutritional and allergenic compounds, their poor technological properties, and their unpleasant sensory characteristics. Fermentation has been traditionally applied to counteract these inconveniences. At present, lactic acid fermentation of legumes is attracting the attention of researchers and industry in relation to the development of healthier, tasty, and technologically adapted products. Hence, we aimed to review the literature to shed light on the effect of lactic acid fermentation on legume protein composition and on their nutritional, functional, technological, and sensorial properties. The antimicrobial activity of lactic acid bacteria during legume fermentation was also considered. The heterogenicity of raw material composition (flour, concentrate, and isolate), the diversity of lactic acid bacteria (nutriment requirements, metabolic pathways, and enzyme production), and the numerous possible fermenting conditions (temperature, time, oxygen, and additional nutrients) offer an impressive range of possibilities with regard to fermented legume products. Systematic studies are required in order to determine the specific roles of the different factors. The optimal selection of these criteria will allow one to obtain high-quality fermented legume products. Fermentation is an attractive technology for the development of legume-based products that are able to satisfy consumers’ expectations from a nutritional, functional, technological, and sensory point of view.

Bridging the Gaps between Plant and Human Health: A Systematic Review of Soyasaponins

Saponins, prominent secondary plant metabolites, are recognized for their roles in plant defense and medicinal benefits. Soyasaponins, commonly derived from legumes, are a class of triterpenoid saponins that demonstrate significant potential for plant and human health applications. Previous research and reviews largely emphasize human health effects of soyasaponins. However, the biological effects of soyasaponins and their implications for plants in the context of human health have not been well-discussed. This review provides comprehensive discussions on the biological roles of soyasaponins in plant defense and rhizosphere microbial interactions; biosynthetic regulation and compound production; immunological effects and potential for therapeutics; and soyasaponin acquisition attributed to processing effects, bioavailability, and biotransformation processes based on recent soyasaponin research. Given the multifaceted biological effects elicited by soyasaponins, further research warrants an integrated approach to understand molecular mechanisms of regulations in their production as well as their applications in plant and human health.

Evaluation of spermicidal activity of saponosides from Saponaria officinalis/Caryophyllaceae, Glycyrrhizia glabra/Fabaceae and Herniaria glabra/Caryophyllaceae

Background and objective

Chemical spermicides currently marketed and widely used are known to have many side effects. Thereby, and in order to look for more tolerated natural spermicidal agents, the aim of this work was to evaluate the spermicidal potential of saponin extracts from the roots of Saponaria officinalis/Caryophyllaceae, Glycyrrhizia glabra/Fabaceae, and Herniaria glabra/Caryophyllaceae by studying their in vitro effects on sperm mobility and vitality.

Methods

Methanolic saponin extracts from the plants roots were performed. Sperm suspensions were prepared by centrifugation on a PureSperm® density gradient (70 and 45%) and incubated with various concentrations of saponin extracts (50, 250, 500 and 750 μg/mL) at 37°C. The spermicidal activity was evaluated by studying the mobility and vitality of spermatozoa at different time intervals ranging from 10 to 240 minutes.

Results

A dose and time dependent effect on sperm mobility and vitality was observed for our extracts.

Extracts from Saponaria officinalis roots induced an irreversible immobilization and a total non-viability of sperm within 10 minutes at a concentration of 750 μg/mL. A similar effect was observed within 30 minutes at 750 μg/mL for Herniaria glabra extract and within 90 minutes at 500 μg/ml for Glycyrrhizia glabra extract.

Conclusion

The results of our study showed that the saponin extracts of our plants roots possess potent in vitro dose and time dependant spermicidal effect. These natural products could therefore represent a safer and better tolerated alternative to chemical spermicides.

Persimmon vinegar ripening with the mountain-cultivated ginseng ingestion reduces blood lipids and lowers inflammatory cytokines in obese adolescents

[Purpose]

This study investigated the effect of the vinegar, which is made of 4-year-old mountain-cultivated ginseng ripened into 4-year-matured persimmon vinegar, on the blood lipids level and inflammatory cytokines concentration in obese female adolescents.

[Methods]

Subjects ingested the vinegar, so-called 'mountain-cultivated ginseng persimmon vinegar (MPV)', without meals every day for 6 weeks with activities control. Subjects were grouped into control (CON), persimmon vinegar (PV), and MPV with 10 people in each group. Blood lipids, triglyceride (TG), total-cholesterol (TC), and high density lipoprotein-cholesterol (HDL-C) were analyzed. Also, glutamic oxaloacetic transaminase (GOT) and glutamate pyruvate transaminase (GPT) were analyzed for the hepatotoxicity. Blood cytokines, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) were analyzed.

[Results]

Subjects showed a high reduction in body weight and body fat. Their blood lipid level was effectively improved, and the secretion of inflammatory cytokine was suppressed as well, except for TNF-α. However, the change ratio of the cytokines was high in PV and MPV. Such results were similar to those from research subjects who took persimmon vinegar only (PV), but the effect of the vinegar (MPV) was more remarkable. Besides, this mixture was found to have no effect on the hepatotoxicity.

[Conclusion]

The significance of this study is that all the experiments were conducted without controlling research subjects' daily lives, and it is suggested that the vinegar may be recommended as a kind of health supplement food to suppress obesity. Especially, since these two products are traditional foods of Korean people, which have been taken for ages, it is expected that the fusing of two foods may be better applied to ordinary people who are concerned about obesity.

Effects of feeding various levels of full fat soybean extruded at high temperature on performance, serum components and intestinal morphology of broiler chickens

This study was conducted to evaluate the effect of dietary levels of extruded full fat soybean (EFFSB) on growth performance, physiological enzymes and intestinal morphology of broiler chickens at market age. A batch of FFSB was wet-extruded at 170°C for 15 s to provide the EFFSB. Ross 308 male broiler chicks (144 one-day old) were divided into 12 groups of 12 birds each and allocated to one of the starter, grower and finisher diets containing 0%, 7.5% and 15% of EFFSB. Feed intake and weight gain of chicks fed the diet containing 15% of EFFSB were significantly (P < 0.05) reduced compared with those fed the control diet during 0–10 days of age, but were not influenced during grower and finisher stages and the whole period (P > 0.05). The triglyceride and low-density lipoprotein (LDL) concentrations in blood serum were significantly (P < 0.05) decreased with an increase in dietary levels of EFFSB at 42 days of age. Length of villi and villus absorptive surface area in duodenum section were linearly decreased (P < 0.05) with an increase in dietary level of EFFSB (P < 0.05), although crypt depth and villus length : crypt depth ratio were not affected (P > 0.05). These morphological criteria were not affected by the dietary level of EFFSB measured in jejunum and ileum sections (P > 0.05). It is concluded that the use of EFFSB in feed may reduce the duodenal surface area and serum triglyceride and LDL cholesterol concentrations, but has no effect on performance of broiler chickens at market age.

Biological functionality of soyasaponins and soyasapogenols

Soyasaponins are a group of structurally complex oleanane triterpenoids primarily found in soybeans and have diverse biological properties. The recent investigations and findings (since 2000) regarding the biological functions of soyasaponins and their aglycones, including their anti-inflammatory, antimutagenic, anticarcinogenic, antimicrobial, and hepato- and cardiovascular-protective activities, are herein summarized. The primary conclusion is that the use of soyasaponins and soyasapogenols in functional foods should be considered.

Dietary soybean peptides containing a low-molecular fraction can lower serum and liver triglyceride levels in rats

We investigated the effects of dietary soybean peptides, particularly low-molecular-weight peptides, on serum and hepatic concentrations of lipids in rats. Soybean protein isolate (SPI) was digested with protease to produce low-molecular-weight peptides (LD) or a mixture of high- and low-molecular-weight peptides (HLD). Rats were fed diets containing 20% casein, SPI, LD or HLD as a nitrogen source, with or without 0.5% cholesterol, for 2 wk. Next, rats were fed cholesterol-free diets containing 0%, 5%, 10%, or 20% LD at the expense of casein for 2 wk. Serum triglyceride levels were the lowest in the LD group, and liver triglyceride levels were significantly lower in rats fed SPI and LD/HLD diets than in those fed casein diets, both in the presence and absence of dietary cholesterol. In addition, dietary LD significantly lowered serum and liver triglyceride levels in a dose-dependent manner. These results suggest that low-molecular-weight soybean peptides have a potent hypotriglyceridemic effect and may be beneficial for improving lipid metabolism.

Soy Saponins Meditate the Progression of Colon Cancer in Rats by Inhibiting the Activity of β -Glucuronidase and the Number of Aberrant Crypt Foci but Not Cyclooxygenase-2 Activity

Objective. The effect of extracted crude soybean saponins on preneoplastic lesions, aberrant crypt foci (ACF), and the related mechanism were investigated. Research Methods and Procedures. Rats were assigned into five groups according to different doses of extracted crude soybean saponins and received 1,2-dimethylhydrazine (DMH) injection in week 5. In week 15, all rats were sacrificed. The number of ACFs, the cyclooxygenase-2 (COX-2) protein expression, the level of prostaglandins E2 (PGE2), and the activity of β-glucuronidase were examined. Results. Results revealed that the consumption of extracted crude soybean saponins decreased the number of ACFs and the activity of β-glucuronidase in rats, while the expression of COX-2 protein and PGE2 level were not affected. Conclusions. Soybean saponins were effective in inhibiting colon cancer by downregulating the activity of β-glucuronidase in colonic mucosa but not the COX-2 protein expression and PGE2 level.

Soy isoflavone delays the progression of thioacetamide-induced liver fibrosis in rats

OBJECTIVE

Our aim was to investigate the effect of soy isoflavone (SI) on liver fibrosis in a thioacetamide (TAA)-induced rat model.

MATERIALS AND METHODS

Twenty-eight rats were assigned to four groups: sham group, fibrosis group, low-dose treatment group (LDg) and high-dose treatment group (HDg). SI (90 or 270 mg/kg) was administered daily during the model development by TAA. Standard liver tests, platelet derived growth factor-BB (PDGF-BB) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured. The expression of collagen, α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) in liver tissue was determined. Electron microscopy was used to perform ultrastructural analysis of the livers.

RESULTS

Hepatic fibrosis was induced by 8 weeks of TAA administration. However, following the administration of SI, collagen staining significantly declined as compared with the fibrosis group (p < 0.01). Less collagen fibers around the hepatic stellate cells (HSCs) were observed in HDg as compared to the fibrosis group and LDg. There was no significant difference in standard liver tests between the fibrosis group and the two treatment groups. The levels of PDGF-BB and TIMP-1 in the two SI-treated groups were significantly lower than in the fibrosis group (p < 0.01). The expression of α-SMA and TGF-β1 in HDg was less than that in the fibrosis group and LDg (p < 0.01).

CONCLUSION

Administration of a high dose of SI resulted in an obvious inhibitory effect on liver fibrosis induced by TAA in rats. One hypothesis is that the effect may be related to the inhibition of HSC activation and proliferation.

[Sperm immobilizing effect of leaves extracts of Cestrum parqui]

OBJECTIVE

The leaves extracts of Cestrum parqui were reported to have spermicidal activity. The current investigation identified the spermicidal component of the extracts and evaluated its spermicidal potential in vitro, particularly the effects on sperm motility and vitality.

METHODS

Sperms were prepared by discontinuous buoyant density gradient centrifugation and incubated with varying concentrations of extract from C. parqui (40-250 μg/ml) at 37°C and 5% CO(2). The mode of spermicidal action was evaluated by sperm motility and vitality at different intervals ranging from 5 to 240 minutes. Morphological changes in human spermatozoa after exposure to the extract were evaluated under transmission electron microscope.

RESULTS

A dose- and time-dependent effect of this extract on sperm motility and viability was observed. The mean effective concentration of extracts that induced irreversible immobilization was 250 μg/ml. Transmission electron microscope revealed a significant damage to sperm membrane in head and acrosomal membranes, notable swelling and disruption.

CONCLUSION

Our study indicates that this natural extract has potential spermicidal effect in vitro. It can adequately replace nonoxynol-9 in vaginal contraceptives to make them more vaginally safe and ecofriendly.

Dietary Karaya Saponin and Rhodobacter capsulatus Exert Hypocholesterolemic Effects by Suppression of Hepatic Cholesterol Synthesis and Promotion of Bile Acid Synthesis in Laying Hens

This study was conducted to elucidate the mechanism underlying the hypolipidemic action of karaya saponin or Rhodobacter (R.) capsulatus. A total of 40 laying hens (20-week-old) were assigned into four dietary treatment groups and fed a basal diet (as a control) or basal diets supplemented with either karaya saponin, R. capsulatus, or both for 60 days. The level of serum low-density-lipoprotein cholesterol and the levels of cholesterol and triglycerides in the serum, liver, and egg yolk were reduced by all the supplementations (P < .05). Liver bile acid concentration and fecal concentrations of cholesterol, triacylglycerol, and bile acid were simultaneously increased by the supplementation of karaya saponin, R. capsulatus, and the combination of karaya saponin and R. capsulatus (P < .05). The supplementation of karaya saponin, R. capsulatus, and the combination of karaya saponin and R. capsulatus suppressed the incorporation of (14)C from 1-(14)C-palmitic acid into the fractions of total lipids, phospholipids, triacylglycerol, and cholesterol in the liver in vitro (P < .05). These findings suggest that the hypocholesterolemic effects of karaya saponin and R. capsulatus are caused by the suppression of the cholesterol synthesis and the promotion of cholesterol catabolism in the liver.

Karaya root saponin exerts a hypocholesterolemic response in rats fed a high-cholesterol diet

Different sources of saponins are known to have hypocholesterolemic activity with varying degrees of efficacy. We hypothesize that karaya root saponin would efficiently reduce cholesterol. The aim of this study is to examine the comparative hypocholesterolemic effect of karaya root saponin in rats fed a high-cholesterol diet. Sixty male Wister-Imamichi rats were divided into 5 groups of 12 rats each constituting of the following: control group, soybean saponin-supplemented group, karaya root saponin-supplemented group, quillaja saponin-supplemented group, and tea saponin-supplemented group. Compared with the control diet, both the karaya root- and quillaja saponin-supplemented diets significantly reduced (P < .05) serum cholesterol and atherogenic index. Karaya root saponin significantly increased the serum high-density lipoprotein cholesterol, high-density lipoprotein cholesterol/cholesterol ratio, and fecal cholesterol concentrations (P < .05). The triacylglycerol concentration was significantly reduced only in the quillaja saponin-supplemented rats (P < .05). All the tea, soybean, karaya root, and quillaja saponins significantly reduced low-density lipoprotein cholesterol, and the greatest reduction was observed with karaya root saponin. Highest fecal bile acid concentration was found with quillaja saponin, whereas highest liver bile acid concentration was observed with karaya root saponin-supplemented rats (P < .05). These results collectively suggest that karaya root saponin can efficiently reduce serum cholesterol concentration in rats.

Cholesterol-lowering properties of whole cowpea seed and its protein isolate in hamsters

Hypercholesterolemic hamsters were fed for 4 wk on diets rich in saturated fatty acids and cholesterol, differing only in protein source (20 %): casein (control group, HC), whole cowpea seed (HWS), and cowpea protein isolate (HPI). Hamsters fed on HWS and HPI presented significant reductions in plasma total cholesterol and non-HDL cholesterol. HPI and HC presented similar protein digestibility, which were significantly higher than that of HWS. Animals fed on HWS presented significantly higher levels of bile acids and cholesterol in feces than did the animals fed on casein or HPI diets. Histological analyses of the liver showed that HC diet resulted in steatosis widely distributed throughout the hepatic lobule, while HWS and HPI diets promoted reductions in liver steatosis. The effectiveness of HWS for modulating lipid metabolism was greater than that of HPI, as measured by plasma cholesterol reduction and liver steatosis.

A Milk Diet Partly Containing Soy Protein Does Not Change Growth but Regulates Jejunal Proteins in Young Goats

Soy protein is known to alter intestinal function and structure. We determined in young goats whether a diet partly containing soy protein differently affects intestinal morphology and the jejunal and hepatic proteome as compared with a milk diet. Fourteen male 2-wk-old White German dairy goat kids were fed comparable diets based on whole cow's milk in which 35% of the crude protein was casein (milk protein group; MP) or soy protein supplemented by indispensable AA (SPAA) for 34 d (n = 7/group). Body weight gain and food efficiency were not different. Jejunal and hepatic tissue was collected to determine intestinal morphology by microscopy and protein repertoire by 2-dimensional gel electrophoresis and mass spectrometry. Jejunal crypt depth was reduced and villus height to crypt depth ratio was higher in SPAA than in milk protein. Out of 131 proteins identified, 32 proteins were found to be differently expressed in both groups. In SPAA, down-regulated jejunal proteins were involved in processes related to cytoskeleton generation, protein, lipid, and energy metabolism. Downregulated hepatic proteins were related to glycolysis and Krebs cycle. Thirteen proteins were upregulated in SPAA. Among these, 2 hepatic proteins were related to carbohydrate breakdown. The other 11 jejunal proteins were involved in cytoskeleton assembly, proteolysis, and carbohydrate breakdown. In addition, glutathione-S-transferase was found to be upregulated in the medial jejunum. In conclusion, a SPAA diet as compared with a milk diet was related to changes in jejunal morphology and jejunal proteins relevant for protein turnover, energy metabolism, and cytoskeleton assembly with no apparent impact on animal BW gain.

Dietary lupin protein lowers triglyceride concentrations in liver and plasma in rats by reducing hepatic gene expression of sterol regulatory element-binding protein-1c

BACKGROUND

Recently, it has been shown that dietary lupin protein lowers plasma triglyceride concentrations in rats. In this study, we investigated the hypothesis that this effect is due to a downregulation of sterol regulatory element-binding protein (SREBP)-1c, a transcription factor that regulates the expression of lipogenic enzymes in the livers of rats.

METHODS

Two groups of 12 rats each were fed semisynthetic diets containing 200 g/kg of either casein (control group) or lupin protein from Lupinus albus for 22 days.

RESULTS

Rats fed the diet containing lupin protein had lower concentrations of triglycerides in the liver, plasma and VLDL + chylomicrons (p < 0.05). The concentration of protein in VLDL + chylomicrons was also lower in rats fed lupin protein than in rats fed casein (p < 0.05). The mRNA concentrations of SREBP-1c and fatty acid synthase in the liver were lower in rats fed lupin protein than in rats fed casein (p < 0.05). The mRNA concentrations of lipoprotein lipase in the liver did not differ between both groups of rats.

CONCLUSION

This study confirms that a protein isolated from L. albus is strongly hypotriglyceridemic in rats. It is shown for the first time that this effect is at least in part due to a downregulation of SREBP-1c in the liver which in turn leads to a reduction in hepatic fatty acid synthesis.

Spermicidal activity of extract from Cestrum parqui

OBJECTIVE

The leaf extract of Cestrum parqui was examined for its effects on sperm motility in vitro.

METHODS

Washed sperm were prepared by discontinuous buoyant density gradient centrifugation and incubated with varying concentrations of extract from C. parqui (40-250 microg/mL) at 37 degrees C and 5% CO(2). Sperm motility and viability were assessed at different intervals ranging from 5 to 240 min. Morphological changes in human ejaculated spermatozoa after exposure to the extract were evaluated under transmission electron microscope.

RESULTS

A dose- and time-dependent effect of this extract on sperm motility and viability was observed. The maximal spermicidal effect was observed with a 250-microg/mL dose of the extract. Transmission electron microscope revealed a significant damage to sperm membrane in both head and acrosomal membranes, notable swelling and disruption.

CONCLUSION

The present study indicates that this natural extract has potential spermicidal effect in vitro.