Influence of dietary spices on the in vivo absorption of ingested β-carotene in experimental rats

Animal studies were conducted to evaluate the influence of dietary spice compounds, piperine, capsaicin and ginger, on the absorption of orally administered β-carotene and its conversion to vitamin A. In rats maintained on these spice-containing diets for 8 weeks, concentrations of β-carotene and retinol were determined in the serum, liver and intestine 4 h after a single oral administration of β-carotene. β-Carotene concentration was significantly increased in the serum, liver and intestine of piperine- and ginger-fed rats, suggesting improved absorption of β-carotene. However, retinol concentration was not significantly changed in these animals, suggesting that the bioconversion of β-carotene to vitamin A was not similarly influenced. Between the two enzymes involved in the bioconversion of β-carotene to vitamin A, the activity of intestinal and hepatic β-carotene 15,15'-dioxygenase was either unaffected or lowered by these spice treatments. The activity of intestinal and hepatic retinal reductase was unaffected by the dietary spices. Activities of these two enzymes involved in the bioconversion of β-carotene to retinal were inhibited by the test spices in vitro, thus corroborating with the in vivo observation. Although the bioconversion of β-carotene was not promoted, increased absorption and tissue levels of β-carotene by the dietary spices may contribute to a higher antioxidant protection.     

Contraceptive efficacy and safety of HerbOshield™ vaginal gel in rats

BackgroundSpermicides represent one of the methods of contraception. The synthetic agents available as spermicides produce severe side effects. Hence, there is a need to replace these agents with safe and effective agents such as plant-based contraceptive agents.Study DesignThe objective of the present study was to develop and evaluate a stable, safe, effective and easily acceptable contraceptive delivery system containing herbal drug. Efforts were made to evaluate the contraceptive potential of the hydroalcoholic extract from the seeds of Annona squamosa Linn. and the vaginal gel HerbOshield? containing the extract.ResultsSpermicidal effect was evaluated in vitro using healthy human spermatozoa and in vivo in rats. The in vitro results demonstrated that HerbOshield? vaginal gel is an effective spermicide. At a 100-mg/mL dose, complete immobilization of human spermatozoa was observed within 20 s. None of the treated animals conceived, indicating 100% contraceptive effect as compared to Gynol II, a nonoxynol-9-containing marketed formulation, which showed only 67% contraceptive effect in vivo. HerbOshield? vaginal gel was found to be safe in animals during a 14-day toxicity study.ConclusionsHerbOshield? vaginal gel was found to be safe and effective in rats and could be developed as a potential vaginal contraceptive for future use in humans.     

Effect of the consumption of β-lactoglobulin and epigallocatechin-3-gallate with or without calcium on glucose tolerance in C57BL/6 mice

Interactions between β-lactoglobulin (β-lg) and epigallocatechin-3-gallate (EGCG) may modulate their health benefits. The objective of this study was therefore to investigate the synergistic effect of consuming β-lg and EGCG complexes on glucose tolerance of C57BL/6 male mice given an oral glucose tolerance test (OGTT) and randomized to one of the following treatments administered prior to the OGTT: 1) simulated milk ultrafiltrate (SMUF^-), 2) SMUF^-?+?EGCG, 3) SMUF^-?+?β-lg, 4) SMUF^-?+?EGCG?+?β-lg, 5) SMUF?+?calcium (SMUF⁺) and 6) SMUF⁺?+?EGCG?+?β-lg. We found no significant between-group difference in postprandial glucose response. However, when mice were separated in those who received β-lg from those who did not, we found that the latter displayed significantly higher postprandial glucose concentrations. Our results support the beneficial impact of β-lg on glycemic control and suggest that concomitant EGCG or calcium consumption does not improve this effect.     

Effect of micellar lipids, dietary fiber and β-carotene on lutein bioavailability in aged rats with lutein deficiency

Objective

To determine the effect of various dietary components on the intestinal uptake of lutein in aged rats.

Methods

This study determined the time-course (2, 4, 6, 8 h) plasma and tissue responses of a pharmacologic dose of lutein (200 μM) solubilized in mixed micelles with fat (3%, soybean oil), phosphatidylcholine (PC; 3 mM), lysophosphatidylcholine (lysoPC; 3 mM), dietary fiber (pectin, 1.25%), β-carotene (200 μM), or micelles with no dietary components (control) in aged rats with lutein deficiency.

Results

No lutein was detected in the plasma of rats at 0 h indicating the deficiency. After gavages of lutein, the mean percent area under the curve (picomoles per milliliter per 8 h) of plasma lutein in the fat (91.4), PC (218.0), and lysoPC (94.1) groups were higher (P > 0.05), whereas its level in the dietary fiber and β-carotene groups was lower than the control group. The liver and eye lutein levels of the PC (95.4, 38.67%) and fat (18.2, 143%) groups were significantly higher, whereas the lysoPC (9.6, 27.2%), β-carotene (19.2, 35.4%), and dietary fiber (3.1, 88.4%) groups were lower than the control group.

Conclusion

Results indicate that soybean oil and soy phospholipids greatly sway lutein absorption in aged rats with lutein deficiency. The results also suggest that ingestion of lutein with pectin and β-carotene suppresses lutein absorption. Hence, to improve the absorption of lutein in older adults with macular pigment deficiency, foods with sufficient fat with low dietary fiber and β-carotene may be suggested.     

Chronic sucrose intake reduces the antagonist effect of β-funaltrexamine on morphine-induced antinociception in female but not in male rats

Abstract

Chronic ingestion of a sweet-tasting sucrose solution enhances the pain relieving actions of opioid agonists. These results, taken in conjunction with research demonstrating that sucrose stimulates the production and release of endogenous opioid peptides, have led to the hypothesis that the effects of palatable foods and fluids on pain sensitivity are mediated by the endogenous opioid system. To assess this hypothesis, two studies determined if chronic sucrose intake would block the antagonist effects of the μ-selective opioid antagonist β-funaltrexamine (β-FNA) on morphine-induced antinociception. Female and male Long-Evans rats were maintained on chow and water, or chow, water and a 32% sucrose solution. In Experiment 1, after four weeks on the diets, female rats received 0 or 10mg/kg (subcutaneously (sc)) β-FNA, while in Experiment 2, male and female rats received 0, 5 or 20 mg/kg β-FNA. Six days later, rats were tested for morphine-induced antinociception using the hot-water tail-withdrawal test. Morphine, administered using a cumulative dose regime (1.0, 3.0, 5.6, 10.0 and 31.0 mg/kg sc), led to dose-dependent increases in tail-withdrawal latencies in male and female rats. Males were more sensitive to the pain relieving properties of morphine than females. Sucrose intake increased, while β-FNA decreased the analgesic actions of morphine in males and females. β-FNA was less effective in blocking the antinociceptive actions of morphine in sucrose-fed female rats than in females fed only chow. In contrast, diet had minimal effects on responses to β-FNA in male rats.     

Classification of alcoholics on the basis of plasma β-endorphin concentration

Recent findings suggest that a genetic deficit in opioids may be a biological marker of alcoholism. In other words, decreased plasma concentrations of opioids may be a predisposing factor, rather than a consequence, of alcohol consumption. We attempted to classify 88 randomly chosen individuals as alcoholics or nonalcoholics on the basis of plasma concentration of β-endorphins. This criterion had a sensitivity of 73.30% and a specificity of 79.45%. Its positive predictive value was 42.30%, and its negative predictive value was 93.55%.     

Impact of β-glucan on the Fecal Water Genotoxicity of Polypectomized Patients

The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development.     

The anti-metastatic efficacy of β-ionone and the possible mechanisms of action in human hepatocarcinoma SK-Hep-1 cells

β-Ionone (BI), a precursor for carotenoids, is widely distributed in fruit and vegetables. Recent in vitro studies have demonstrated the potential anti-metastatic effects of BI, but the mechanisms underlying such actions are not clear. Because liver cancer is the most endemic cancer in Taiwan and in a large region of the world, we hereby investigate the anti-metastatic effects of BI and its mechanisms of actions in a highly metastatic human hepatocarcinoma SK-Hep-1 cells. We show that incubation of cells with BI (1-50?μm) for 24 and 48?h significantly inhibited cell invasion, migration and adhesion. Mechanistically, incubation of cells with BI (1-50?μm) for 24?h resulted in the following: (1) significant inhibition of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase-type plasminogen activator activities, (2) up-regulation of protein expression of the tissue inhibitor of matrix metalloproteinase (TIMP)-1, TIMP-2 and plasminogen activator inhibitor-1, (3) down-regulation of the expression of migration-related proteins, including focal adhesion kinase (FAK), phosphorylated form of FAK, Rho, Rac1 and Cdc42 and (4) up-regulation of the expression of nm23-H1 protein (P?相似文献   

Single oral dose of micellar β-carotene containing phospholipids improves β-carotene metabolism and plasma lipids in vitamin A-deficient rats

Background  

Vitamin A (VA) deficiency is still a major health problem in the developing world. It affects various cellular functions and causes hypolipidemic effects in the body. β-Carotene (BC)-rich foods are promising sources of VA. Phospholipids are reported to improve BC bioefficacy in normal rats, but whether they show similar effects during VA deficiency is unknown.     

Effects of barley β-glucan-enriched flour fractions on the glycaemic index of bread

The aim of this research was to evaluate β-glucan-enriched flours, obtained from barleys with either normal or waxy starch, for their effects on the glycaemic index (GI) and the quality of bread. Rheological results confirmed that when barley flour was included in the dough the overall quality of bread slightly worsened. However, positive consequences on glycaemia were obtained with the normal starch barley: the GI of all-wheat bread (82.8?±?7.2) was significantly reduced (57.2?±?7.9) when 40% of wheat flour was substituted with β-glucan-enriched barley flour (6.0%?±?0.1 β-glucan in the final flour blend). In contrast, this positive effect was significantly reduced (GI: 70.1?±?9.1) when 40% of wheat flour was substituted with the β-glucan-enriched flour of a waxy barley (CDC Alamo; 6.6?±?0.2 β-glucan in the final flour blend), suggesting that the ability of β-glucans to lower the GI was affected by the barley starch-type.     

Inhibitory effect of a fat‐free diet on mammary carcinogenesis in rats

Young female Sprague‐Dawley rats were administered 7,12‐dimethylbenz(a)‐anthracene, and a week later the rats were transferred from commercial feed to a semipurified diet containing 20% corn oil. Eight weeks after receiving the carcinogen, half of the rats were changed to a fat‐free diet to determine the effects on mammary tumor growth and development. After another 20 weeks, rats fed the fat‐free diet had significantly fewer tumors per tumor‐bearing rat and the tumors were smaller than those of rats that continued on the high‐fat diet. Rats fed the fat‐free diet weighed somewhat less, but showed no physical evidence of essential fatty acid deficiency. Tumors regressed in about half of the rats on the fat‐free diet and in some cases became nonpalpable. After 28 weeks on this diet, the remaining rats were transferred back to the high‐fat diet and subsequently showed a marked stimulation in tumor growth and development. This continued even after the rats were returned to the fat‐free diet 8 weeks later, indicating that the tumors were no longer susceptible to the deprivation of dietary fat. The results of this study provide further evidence that dietary fat affects the promotional stage of mammary carcinogenesis.     

Comparison of Two β-Alanine Dosing Protocols on Muscle Carnosine Elevations

Objective: β-alanine (BA) is a nonproteogenic amino acid that combines with histidine to form carnosine. The amount taken orally in individual doses, however, is limited due to symptoms of paresthesia that are associated with higher doses. The use of a sustained-release formulation has been reported to reduce the symptoms of paresthesia, suggesting that a greater daily dose may be possible. The purpose of the present study was to determine whether increasing the daily dose of BA can result in a similar increase in muscle carnosine in a reduced time.

Methods: Eighteen men and twelve women were randomized into either a placebo (PLC), 6-g BA (6G), or 12-g BA (12G) groups. PLC and 6G were supplemented for 4 weeks, while 12G was supplemented for 2 weeks. A resting blood draw and muscle biopsy were obtained prior to (PRE) and following (POST) supplementation. Plasma and muscle metabolites were measured by high-performance liquid chromatography. The loss in peak torque (ΔPT) was calculated from maximal isometric contractions before and after 250 isokinetic kicks at 180°·sec^?1 PRE and POST.

Results: Both 12G (p = 0.026) and 6G (p = 0.004) increased muscle carnosine compared to PLC. Plasma histidine was decreased from PRE to POST in 12G compared to PLC (p = 0.002) and 6G (p = 0.001), but no group x time interaction (p = 0.662) was observed for muscle histidine. No differences were observed for any hematological measure (e.g., complete blood counts) or in symptoms of paresthesia among the groups. Although no interaction was noted in ΔPT, a trend (p = 0.073) was observed.

Conclusion: Results of this investigation indicate that a BA supplementation protocol of 12 g/d^?1, using a sustained-release formulation, can accelerate the increase in carnosine content in skeletal muscle while attenuating paresthesia.     

Regulation of iron metabolism in Hamp −/− mice in response to iron-deficient diet

Background

Hepcidin, the liver-secreted iron regulatory peptide, maintains systemic iron homeostasis in response to several stimuli including dietary iron levels and body iron status. In addition, iron metabolism is controlled by several local regulatory mechanisms including IRP and Hif-2α activities independently of hepcidin. However, the roles of these mechanisms and their interaction particularly in hepcidin-deficient individuals are not yet fully understood. We, therefore, aimed to explore whether Hamp disruption affects iron homeostatic responses to dietary iron deficiency.

Methods

Hepcidin1 knockout (Hamp ^?/?) mice and heterozygous littermates were fed with control or iron-deficient diet for 2 weeks. The expression of iron-related genes and proteins were determined by quantitative PCR and Western blot, respectively.

Results

Two-week iron-deficient diet feeding in Hamp ^?/? mice did not alter serum iron but significantly reduced liver non-heme iron levels. This was also associated with increased ferroportin protein expression in the duodenum and spleen, whereas decreased expression was found in the liver. In addition, significant inductive effects of iron-deficient diet on Dcytb and DMT1 mRNA expression in the duodenum were noted with more pronounced effects in Hamp ^?/? mice compared with controls.

Conclusions

Hamp ^?/? mice exhibited a more dramatic increase in the expression of iron transport machinery, which may be responsible for the unaltered serum iron levels upon iron-deficient diet feeding in these mice. Despite the lack of hepcidin, Hamp ^?/? mice can maintain a degree of iron homeostasis in response to altered dietary iron through several hepcidin-independent mechanisms.     

Meta-analysis of the effect of β-glucan intake on blood cholesterol and glucose levels

Objective

A meta-analysis was performed on epidemiologic studies to assess the relation between β-glucan consumption from oats and from barley on blood cholesterol level, triglyceride/triacylglycerol (TGL/TAG) level, and blood glucose level (BGL) in humans. In addition, the effect of β-glucan on total cholesterol (TC) and BGL was translated into an empirical dose–response model.

Methods

Thirty research articles that evaluated the effect of different exposure levels of β-glucan on blood cholesterol and BGL were analyzed, yielding 126 clinical studies.

Results

There was a significant inverse relation in TC (−0.60 mmol/L, 95% confidence interval [CI] −0.85 to −0.34), low-density lipoprotein (−0.66 mmol/L, 95% CI −0.96 to −0.36), and TGL/TAG (−0.04 mmol/L, 95% CI −0.15 to 0.07) after consumption of β-glucan. In contrast, an increase in high-density lipoprotein cholesterol was noted (0.03 mmol/L, 95% CI −0.06 to 0.13) with the random-effect model. The analysis showed a significant change in BGL (−2.58 mmol/L, 95% CI −3.22 to −1.84) with high heterogeneity between (I² = 97%) and across (τ² = 5.88) the studies. The fixed-effect model showed a significant change in TC, low-density lipoprotein, and BGL, whereas it showed no significant changes in high-density lipoprotein and TGL/TAG. The dose–response model showed that a 3-g/d dose of oat or barley β-glucan was sufficient to decrease TC.

Conclusion

Consumption of 3 g/d of oat or barley β-glucan is sufficient to decrease blood cholesterol, whereas the effect on BGL is still inconclusive, with high heterogeneity, and requires further clinical research studies with longer intervention periods.     

Preventive effect of probiotics and α-tocopherol on ethanol-induced gastric mucosal injury in rats

The protective effect of a probiotic mixture of 13 different bacteria and α-tocopherol on 98% ethanol-induced gastric mucosal injury was evaluated. Levels of gastric mucosal pro- and anti-inflammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Rats were allocated into four groups: control, ethanol, probiotic, and α-tocopherol. The control and ethanol groups received skim milk for 14 days. Probiotic and α-tocopherol groups were administered probiotic mixture suspended in skim milk and 100?mg/kg α-tocopherol, respectively, by daily gavage for 14 days. On Day 15, gastric lesions were induced by administration of ethanol 98% (1?mL) to all rats except those in the control group. Probiotic, but not α-tocopherol, seemed to inhibit ethanol-induced gastric mucosal tumor necrosis factor-α, interferon-γ, and interleukin-2 production (P?>?.05). Ethanol caused the elevation of mucosal interleukin-4 level (compared to the control, P?相似文献   

Effects of curcuminoid supplement on cardiac autonomic status in high-fat–induced obese rats

ObjectiveSudden cardiac death in obesity is frequently associated with sympathetic activation due to an elevated plasma free-fatty acid (FFA) level. Curcuminoids, the phenolic yellowish pigments of turmeric, display antioxidative and lipid-lowering activities. We hypothesized that curcuminoids ameliorate cardiac sympathovagal disturbance in high-fat–induced obese rats.MethodsMale Wistar rats were divided into five groups. A normal-diet control (NDC) group received a normal-fat diet (12% calories as fat) and a high-fat–diet control (HDC) group received a high-fat diet (60% calories as fat) for 12 wk. Three other groups received high-fat diets with curcuminoid supplement at concentrations of 30 mg (HD₃₀), 60 mg (HD₆₀), and 90 mg (HD₉₀) per kilogram of body weight every day for 12 wk. Heart rate variability was determined to assess cardiac autonomic status at weeks 0 and 12.ResultsBody weight, visceral fat mass, plasma FFA, and glucose levels increased significantly in the HDC group compared with the NDC group. Low frequency power in normalized units (LFnu) and the ratio of LF to high-frequency power (HF) in the HDC group were significantly higher, whereas HFnu in the HDC group was significantly lower than in the NDC group. Plasma FFA levels correlated significantly with LFnu and LF/HF ratio. Compared with the HDC group, plasma FFA, glucose levels, LFnu, and LF/HF ratio were significantly decreased in the HF₃₀, HF₆₀, and HF₉₀ groups.ConclusionElevated plasma FFA in high-fat–induced obese rats is associated with an increased LF/HF ratio, an expression of sympathovagal disturbance. Curcuminoid supplementation ameliorates cardiac autonomic imbalance in high-fat–fed rats, probably due to its lipid-lowering effect.     

The influence of professional development on changes in educators’ facilitation of complex thinking in preschool classrooms

Over a three-year period, 20 educators, who worked at a preschool in Hawaii serving two- to five-year-old children, participated in professional development designed to promote complex thinking among young learners. Six times each year, the educators were video-recorded while teaching to assess their use of strategies that facilitate complex thinking. Results indicated that across time, the professional development promoted teachers’ use of strategies to promote children's complex thinking increased, and the trajectories of all teachers’ strategy use increased at similar growth rates. Teachers who worked with younger children used the strategies to a lesser degree. Consistent with previous research on effective professional development, findings suggest the positive influences of professional development that goes beyond the ‘one shot’ workshop to promote the practice of new strategies, feedback, and reflection.