Increase in Swimming Endurance Capacity of Mice by Capsaicin-induced Adrenal Catecholamine Secretion

Increase in endurance swimming capacity caused by capsaicin (CAP), a pungent component of red pepper, -induced increase of fat metabolism in mice was investigated using an adjustable-current water pool. The mice administered CAP via a stomach tube, showed longer swimming time until exhaustion than the control group of mice, in a dose-dependent manner. The maximal effect was observed at a dose of 10 mg/kg while more than 15 mg/kg had no effect. The increase of endurance was observed only when CAP was administered two hours before swimming. After the administration of CAP, the serum glucose concentration rapidly increased and then decreased within 60min, while the concentration of serum-free fatty acids gradually increased through 3 hours. The residual glycogen concentration of the gastrocnemius muscle after 30 min of swimming was significantly higher in the CAP-administered mice than in control mice, suggesting that use of the serum free fatty acids spared muscle glycogen consumption. The serum adrenaline concentration significantly increased with twin peaks at 30 min and two hours after administration of CAP. An experiment using adrenalectomized mice was done to confirm that the effect of CAP is due to increased energy metabolism through the secretion of adrenaline from the adrenal gland. The swimming endurance capacity of the adrenalectomized mice was not increased by CAP administration, although adrenaline injection induced a 58% increase in the endurance time. These results suggest that the increase of swimming endurance induced by CAP in mice is caused by an increase in fatty acid utilization due to CAP-induced adrenal catecholamine secretion.     

Administration of capsiate, a non-pungent capsaicin analog, promotes energy metabolism and suppresses body fat accumulation in mice

We investigated the effects of a single oral administration of capsiate, which is found in the fruits of a non-pungent cultivar of pepper, CH-19 Sweet, and has the same structure as capsaicin except for replacement of NH by O in the alkyl chain, on the thermogenesis and fat accumulation in mice. The oxygen consumption and serum adrenalin concentration were higher in both the capsaicin (10 mg/kg-body weight) and capsiate (10 mg/kg-body weight) groups than those in the control group. We also examined the effects of 2 weeks of administration of capsaicin and capsiate on body fat accumulation. Eevery day for 2 weeks administration of capsiate (10, 50 mg/kg-body weight/day) markedly suppressed body fat accumulation as well as capsaicin (10 mg/kg-body weight/day). These results suggest that capsiate promotes energy metabolism and suppresses body fat accumulation as does capsaicin.     

Enhancement of exercise endurance capacity by fermented deer antler in BALB/c mice

To investigate the activity of fermented deer antler on exercise endurance capacity, we evaluated endurance capacity in five-week-old male BALB/c mice by administering the fermented deer antler extract (FA) or the non-fermented deer antler extract (NFA) and then subjected the mice to exercise in the form of swimming. The mice administered 500?mg/kg/day of FA showed a significant increase in swimming time compared with mice administered placebo (16.55?min vs. 21.64?min, P?<?0.05). Serum lactate dehydrogenase (LDH), the marker of the liver and muscle damage, was significantly lower in FA groups. However, NFA groups did not show significantly different swimming time or serum LDH from that of the control group. Moreover, the FA-500 group had significantly higher hepatic superoxide dismutase (SOD) activity after forced swimming than the control and NFA groups (P?<?0.05). These findings suggest that fermentation may increase the exercise endurance capacity of the deer antler.     

植物提取物槲皮素调节小鼠的能量代谢和氧化应激

为了探讨植物提取物槲皮素对负重游泳小鼠的能量代谢和氧化应激的影响,本研究将45只SPF级雄性昆明小鼠随机分为正常对照组、游泳组和槲皮素组,每组15只。槲皮素组小鼠喂养2 g/kg的槲皮素饲料,其他组小鼠喂养标准饲料,共喂养14 d。然后将游泳组和槲皮素组小鼠按照体重的3%进行负重游泳1 h,测定各组小鼠的血糖、乳酸、尿素氮、游离脂肪酸、琥珀酸脱氢酶、三磷酸腺苷、丙二醛、谷胱甘肽过氧化物酶和总抗氧化活性。结果显示,负重游泳后,槲皮素组血清乳酸和尿素氮水平显著低于游泳组,并且槲皮素组游离脂肪酸水平显著高于游泳组。负重游泳后,游泳组小鼠的肝脏和肌肉组织中的琥珀酸脱氢酶含量均显著降低,槲皮素组小鼠游泳后未见明显降低。负重游泳后,游泳组小鼠肌肉组织中的ATP酶活性显著降低,槲皮素组小鼠游泳后未见明显降低。负重游泳后,槲皮素组的丙二醛含量显著低于游泳组。游泳组和槲皮素组小鼠负重游泳后的谷胱甘肽过氧化物酶含量均显著降低,槲皮素组小鼠的谷胱甘肽过氧化物酶含量未见明显降低。游泳组小鼠血清总抗氧化活性显著低于对照组,而槲皮素组与对照组无显著差异。本研究初步表明,槲皮素可调节负重游泳小鼠的能量代谢来起到抗疲劳作用,主要机制与增加脂肪动员、抑制蛋白质分解和加强三羧酸循环有关。另外,槲皮素可通过抑制脂质过氧化、清除超氧阴离子自由基来防止运动过程中的氧化应激损伤。     

大豆异黄酮对游泳小鼠能量代谢的影响

目的：探讨大豆异黄酮（SI）对游泳小鼠能量代谢的影响。方法：建立小鼠运动疲劳模型,选用雄性昆明小鼠30只,根据体质量随机分为3组（n=10）：正常组、游泳模型组、游泳+SI干预组（SI组）。正常组及模型组小鼠以AIN-93M合成饲料饲养,SI组在AIN-93M合成饲料中添加相应剂量的SI （4 g/kg）。饲养2周后,模型组和SI组小鼠负重2%游泳1 h后处死,测定其血乳酸（Lac）含量及乳酸脱氢酶（LDH）、琥珀酸脱氢酶（SDH）、肌酸激酶（CK）、ATP酶的活性。结果：与正常组相比,模型组和SI组血清中Lac含量明显增加（P<0.05）,模型组肌肉和SI组血中LDH活性显著升高（P<0.05）,模型组血清、肝脏和肌肉中SDH和CK活性明显升高,SI组血清和肌肉中SDH和CK活性显著升高（P<0.05）;与模型组相比,SI组小鼠游泳后,血清Lac含量明显下降（P<0.05）,LDH、SDH、CK酶活性较模型组都有明显升高（P<0.05）。结论：大豆异黄酮对游泳小鼠能量代谢具有一定的调节作用。     

Capsiate Supplementation Reduces Oxidative Cost of Contraction in Exercising Mouse Skeletal Muscle In Vivo

Chronic administration of capsiate is known to accelerate whole-body basal energy metabolism, but the consequences in exercising skeletal muscle remain very poorly documented. In order to clarify this issue, the effect of 2-week daily administration of either vehicle (control) or purified capsiate (at 10- or 100-mg/kg body weight) on skeletal muscle function and energetics were investigated throughout a multidisciplinary approach combining in vivo and in vitro measurements in mice. Mechanical performance and energy metabolism were assessed strictly non-invasively in contracting gastrocnemius muscle using magnetic resonance (MR) imaging and 31-phosphorus MR spectroscopy (³¹P-MRS). Regardless of the dose, capsiate treatments markedly disturbed basal bioenergetics in vivo including intracellular pH alkalosis and decreased phosphocreatine content. Besides, capsiate administration did affect neither mitochondrial uncoupling protein-3 gene expression nor both basal and maximal oxygen consumption in isolated saponin-permeabilized fibers, but decreased by about twofold the K _m of mitochondrial respiration for ADP. During a standardized in vivo fatiguing protocol (6-min of repeated maximal isometric contractions electrically induced at a frequency of 1.7 Hz), both capsiate treatments reduced oxidative cost of contraction by 30-40%, whereas force-generating capacity and fatigability were not changed. Moreover, the rate of phosphocreatine resynthesis during the post-electrostimulation recovery period remained unaffected by capsiate. Both capsiate treatments further promoted muscle mass gain, and the higher dose also reduced body weight gain and abdominal fat content. These findings demonstrate that, in addition to its anti-obesity effect, capsiate supplementation improves oxidative metabolism in exercising muscle, which strengthen this compound as a natural compound for improving health.     

拟黑多刺蚁提取液可缓解小鼠体力疲劳

研究拟黑多刺蚁Polyrhachis vicina Roger提取液的缓解体力疲劳作用。采用清洁级雄性昆明种小鼠,拟黑多刺蚁水和乙醇双重提取液按8.3mL/kg.bw,16.7mL/kg.bw,25.0mL/kg.bw连续灌胃30d,测定小鼠负重游泳时间、血乳酸、血清尿素氮和肝糖原含量。结果:3个实验组及乙醇对照组小鼠负重游泳时间均显著长于蒸馏水对照组(P<0.05,P<0.01);8.3mL/kg.bw剂量组小鼠负重游泳时间显著长于乙醇对照组(P<0.01)。8.3mL/kg.bw剂量组小鼠3个时点血乳酸曲线下面积显著低于蒸馏水对照组和乙醇对照组(P<0.05、P<0.01),16.7mL/kg.bw剂量组小鼠3个时点血乳酸曲线下面积明显低于蒸馏水对照组(P<0.01)。乙醇对照组及拟黑多刺蚁提取液3个剂量组小鼠血清尿素氮含量均显著低于蒸馏水对照组(P<0.05、P<0.01),16.7mL/kg.bw剂量组小鼠血清尿素氮含量低于乙醇对照组(P<0.05)。拟黑多刺蚁提取液具有缓解体力疲劳的作用。     

Enhancement of swimming endurance in mice by highly branched cyclic dextrin

We investigated the ergogenic effect in mice of administering highly branched cyclic dextrin (HBCD), a new type of glucose polymer, on the swimming endurance in an adjustable-current swimming pool. Male Std ddY mice were administered a HBCD, a glucose solution or water via a stomach sonde 10 min before, 10 min after or 30 min after beginning swimming exercise, and were then obliged to swim in the pool. The total swimming period until exhaustion, an index of the swimming endurance, was measured. An ergogenic effect of HBCD was observed at a dose of 500 mg/kg of body weight, whereas it had no effect at a dose of 166 mg/kg of body wt (p < 0.05). The mice administered with the HBCD solution 10 min after starting the exercise were able to swim significantly longer (p < 0.05) than the mice who had ingested water or the glucose solution. The rise in mean blood glucose level in the mice administered with HBCD, which was measured 20 min after starting swimming, was significantly lower (p < 0.05) than that in the mice administered with glucose, although it was significantly higher (p < 0.05) than that in the mice administered with water. The mean blood insulin rise in the mice given HBCD was significantly lower (p < 0.05) than that in the mice given glucose. The mice administered with HBCD 30 min after starting the exercise swam significantly longer (p < 0.05) than the mice who had ingested water, although the enhancement of swimming time was similar to that of the glucose-ingesting mice. The gastric emptying rate of the HBCD solution was significantly faster (p < 0.05) than that of the glucose solution. However, this glucose polymer must have spent more time being absorbed because it has to be hydrolyzed before absorption, reflecting a lower and possibly longer-lasting blood glucose level. We conclude that the prolongation of swimming endurance in mice administered with HBCD depended on its rapid and longer-lasting ability for supplying glucose with a lower postprandial blood insulin response, leading to a delayed onset of fatigue.     

饲喂雌鼠大豆异黄酮对后代雌性生殖性状的影响

目的研究雌性小鼠饲喂异黄酮后对其后代雌鼠生殖性状的影响。方法分别在雌鼠从断奶到妊娠前和妊娠期间两个不同阶段的日粮中添加不同剂量的大豆异黄酮（0、50、400 mg/kg）。记录F1代的出生窝产仔数、出生窝重、雌鼠的阴道最早开张时间和最早见栓时间,以及后代雌鼠性成熟期和体成熟期生殖器官重量、血清雌激素的含量。结果雌鼠妊娠期饲喂含50、400 mg/kg大豆异黄酮的饲料后F1代的窝产仔数显著高于对照组（P〈0.05）;雌鼠妊娠期采食400 mg/kg大豆异黄酮饲料,其后代雌鼠初次配种时间明显延迟（P〈0.05）;45、65日龄体重显著低于对照组,65日龄子宫重显著低于对照组,卵巢重显著高于对照组;血清中雌激素含量显著低于对照组（P〈0.05）,妊娠期间采食50 mg/kg大豆异黄酮饲料,其F1代雌鼠仅窝产仔数和45日龄时血清中雌激素含量受到影响;而雌鼠从断奶到怀孕期间饲喂含大豆异黄酮饲料的F1代在各项指标与对照组均差异无显著性。结论雌鼠妊娠期间饲喂含400 mg/kg大豆异黄酮的饲料会显著影响其雌性后代的初情期、生殖器官发育、血清雌激素含量等生殖生理性状,而在非妊娠期饲喂含大豆异黄酮饲料对F1代无显著影响。     

柴达木盆地唐古特白刺果实调节免疫、抗疲劳和耐寒冷作用研究

采用环磷酰胺所致的免疫功能低下的模型小鼠试验柴达木盆地唐古特白刺果实的免疫调节作用,并进行了抗疲劳和耐寒冷试验。结果显示：唐古特白刺果实3．6g/kg灌胃剂量能显著增强模型小鼠单核巨噬细胞吞噬功能、迟发性超敏反应;1．8g/kg和3．6/kg灌胃剂量能显著提高模型小鼠血清溶血素生成能力;3．6g/kgg灌胃剂量可显著减轻环磷酰胺对小鼠胸腺DNA含量的抑制作用;3．6g/kg灌胃剂量能显著延长小鼠的游泳时间和爬杆时间,并能提高小鼠在低温的存活时间。实验表明唐古特白刺果实具有调节免疫、抗疲劳和耐寒冷作用。     

秋葵籽油对高强度运动所致肝损伤的保护作用

本研究考察了秋葵籽油对高强度运动所致肝损伤的保护作用及机制。研究显示,对昆明小鼠灌胃不同剂量(10 mg/kg,20 mg/kg和50 mg/kg)的秋葵籽油4周后,秋葵籽油以剂量依赖性方式提高了小鼠的力竭游泳时间(p<0.05)。秋葵籽油降低了小鼠血清乳酸和尿素氮水平,并升高了血清游离脂肪酸和肝糖原水平(p<0.05)。秋葵籽油以剂量依赖性方式提高了小鼠肝脏组织中SOD、CAT和GSH-Px活性,并抑制了MDA的合成(p<0.05)。秋葵籽油抑制了力竭游泳诱导的小鼠血清CK、AST和ALT水平及肝脏组织NO水平的升高(p<0.05)。此外,苏木精和伊红(HE)染色证实了秋葵籽油减轻了力竭游泳诱导的肝脏病理改变。因此,本研究初步结论表明,在高强度运动过程中,秋葵籽油可通过抑制乳酸和尿素氮的积累、增加脂肪动员、降低糖原消耗、减弱氧化应激损伤等多种途径来对肝脏发挥保护作用。     

Cholesterol-lowering effects of maitake (Grifola frondosa) fiber, shiitake (Lentinus edodes) fiber, and enokitake (Flammulina velutipes) fiber in rats

The effects of mushroom fibers on serum cholesterol and hepatic low-density lipoprotein (LDL) receptor mRNA in rats were investigated. Rats were fed a cholesterol-free diet with 50 g/kg cellulose powder (CP), 50 g/kg maitake (Grifola frondosa) fiber (MAF), 50 g/kg shiitake (Lentinus edodes) fiber (SF), or 50 g/kg enokitake (Flammulina velutipes) fiber (EF) for 4 weeks. There were no significant differences in the body weight, food intake, liver weight, cecum weight, and cecum pH among the groups. Cecal acetic acid, butyric acid, and total short-chain fatty acid (SCFA) concentrations in the SF and EF groups were significantly higher than those in the other groups. The serum total cholesterol concentration in the CP group was significantly higher than that in the MAF and EF groups. The very LDL (VLDL) + intermediate-density lipoprotein (IDL) + LDL-cholesterol concentration in the CP group was significantly higher than that in the MAF, SF, and EF groups, whereas the high-density lipoprotein (HDL)-cholesterol concentration in the EF group was significantly lower than that in the other groups at the end of the 4-week feeding period. The hepatic LDL receptor mRNA level in the EF group was significantly higher than that in the CP group. The fecal cholesterol excretion in the MAF, SF, and EF groups was significantly higher than that in the CP group. The results of this study demonstrate that MAF and EF lowered the serum total cholesterol level by enhancement of fecal cholesterol excretion, and in particular, by enhancement of hepatic LDL receptor mRNA in EF group.     

Effects of Dietary Selenium, Vitamin E, and Their Combination on Growth, Serum Metabolites, and Antioxidant Defense System in Skeletal Muscle of Broilers Under Heat Stress

This experiment was conducted to evaluate the effects of dietary vitamin E, selenium (Se), and a combination of the two, on the performance, serum metabolites and oxidative stability of skeletal muscle of broilers during heat stress. The broilers raised in either a thermoneutral (23.9°C constant) or heat stress (23.9°C to 37°C cycling) environment were assigned to 6 dietary treatments (0, 0.5, or 1 mg/kg Se; 125 and 250 mg/kg vitamin E; or 0.5 mg/kg Se plus 125 mg/kg vitamin E) from 1 to 49 days of age. At the end of the experiment, blood samples were collected from chicks, the chicks sacrificed, and pectoralis superficialis muscle was used for measurement of malondialdehyde (MDA) concentration and enzyme activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD). The heat-stressed chicks consumed less feed, gained less weight, and had higher feed conversion ratio when compared to thermoneutral chicks (P<0.05). Serum concentrations of iron (Fe) and zinc (Zn) were decreased by heat stress (P<0.05), whereas the serum concentrations of copper (Cu), glucose, and uric acid were significantly increased under heat stress (P<0.05). The chicks that received supplemental of vitamin E exhibited significantly higher serum concentrations of Zn (P<0.05) and significantly lower concentrations of Cu, glucose, and uric acid (P<0.05) when exposed to heat stress. Dietary Se also caused a significant decrease in serum glucose, uric acid, and Cu concentrations of heat-stressed broilers (P<0.05), but had no significant effect on Zn concentration (P>0.05). The GPx activity remained relatively constant (P>0.05), though SOD activity and MDA levels in skeletal muscle were enhanced on exposure to heat stress (P<0.05). The heat-stressed chicks that received the combined supplementary level of vitamin E and Se had the lowest concentration of MDA and the highest activity of SOD in the skeletal muscle (P<0.05). Dietary Se also caused a significant increase in enzyme activity of GPx in the skeletal muscle (P<0.05). These results indicate that the derangement of blood parameters and oxidative stability in broilers under heat stress are improved by supplemental vitamin E and Se.     

Inhibition by a Capsaicin Antagonist (Capsazepine) of Capsaicin-induced Swimming Capacity Increase in Mice

We investigated the endurance swimming capacity of mice injected with CAP antagonist (capsazepine). The increase of endurance swimming capacity by the administration of CAP was significantly suppressed by the injection of capsazepine. At the same time, serum adrenaline secretion, which was induced by CAP, was depressed by capsazepine. These findings suggested that the increase in endurance swimming capacity by CAP was mediated by the CAP receptor.     

猴头菇对小鼠抗疲劳作用的实验研究

分别以猴头菇干粉（猴头菇Ⅰ组）和猴头菇浸出液（猴头菇Ⅱ组）饲喂小鼠,观察猴头菇对小鼠血清乳酸脱氢酶（ＬＤＨ）活力、血乳酸、血清尿素氮（ＢＵＮ）、肝糖原、肌糖原含量及运动耐力的影响。结果表明：实验６０ｄ后,猴头菇Ⅰ、Ⅱ组ＬＤＨ活力、肝糖原及肌糖原含量明显高于对照组（Ｐ＜０．０５或Ｐ＜０．０１）;运动后血乳酸的水平和ＢＵＮ的增量明显低于对照组（Ｐ＜０．０５或Ｐ＜０．０１）;运动后血乳酸消除速率显著高于对照组（Ｐ＜０．０５）;在运动耐力测定时在水中淹死的时间比对照组长得多（Ｐ＜０．０５）。提示：猴头菇具有明显的增强运动能力和解除疲劳的作用。     

Involvement of capsaicin-sensitive sensory nerves in cardioprotection of rutaecarpine in rats

In the present study, we examined whether rutaecarpine protects against myocardial ischemia-reperfusion injury in rats and whether the protective effects of rutaecarpine are related to activation of capsaicin-sensitive sensory nerves. Rats were pretreated with rutaecarpine 10 min before the experiment, and then the left main coronary artery of rat hearts was subjected to 60-min occlusion followed by 3-h reperfusion. The infarct size, serum concentration of creatine kinase, and CGRP concentration in plasma were measured. Pretreatment with rutaecarpine (100 or 300 microg/kg, i.v.) significantly reduced infarct size and creatine kinase release concomitantly with a significant increase in plasma concentrations of CGRP. These effects of rutaecarpine were completely abolished by capsazepine (38 mg/kg, s.c.), a competitive vanilloid receptor antagonist, or by pretreatment with capsaicin (50 mg/kg, s.c.), which selectively depletes transmitters in capsaicin-sensitive sensory nerves. These results suggest that rutaecarpine protects against myocardial ischemia-reperfusion injury in rats and that the protective effects of rutaecarpine are related to activation of capsaicin-sensitive sensory nerves via activating vanilloid receptors.     

γ-氨基丁酸茶对小鼠抗疲劳作用的研究

目的:研究γ-氨基丁酸茶对小鼠的抗疲劳作用.方法:采用昆明种小鼠游泳力竭实验,实验动物分为γ-氨基丁酸茶高、中和低实验组及空白对照组,分别检测游泳力竭时间,测定小鼠血糖、肝糖原、肌糖原,血清BUN、LDH、CK、SOD、MDA、GSH-PX,以及游泳前后的血乳酸.结果:γ-氨基丁酸茶对小鼠的实验期间的体重无明显影响.力...     

Effects of L-malate on physical stamina and activities of enzymes related to the malate-aspartate shuttle in liver of mice

L-malate, a tricarboxylic acid cycle (TCA) intermediate, plays an important role in transporting NADH from cytosol to mitochondria for energy production and may be involved in the beneficial effects of improving physical stamina. In the present study, we investigated the effects of L-malate on the performance of forced swimming time and blood biochemical parameters related to fatigue - blood urea nitrogen (BUN), glucose (Glc), creatine kinase (CK),total protein (TP) and lactic acid (LA). To investigate the effects of L-malate on the malate-aspartate shuttle and energy metabolism in mice, the activities of enzymes related to the malate-aspartate shuttle were measured. L-malate was orally administered to mice continuously for 30 days using a feeding atraumatic needle. The swimming time was increased by 26.1 % and 28.5 %, respectively, in the 0.210 g/kg and 0.630 g/kg L-malate-treated group compared with the control group. There were no differences in the concentrations of Glc, BUN and TP between the L-malate-treated groups and the control groups. However, the levels of CK were significantly decreased in the L-malate-treated groups. The results predict a potential benefit of L-malate for improving physical stamina and minimizing muscle damage during swimming exercise. The activities of cytosolic and mitochondrial malate dehydrogenase were significantly elevated in the L-malate-treated group compared with the control group. These enzymatic activities may be useful indicators for evaluating changes affecting the malate-aspartate shuttle and energy metabolism in the liver of mice.     

饲料中添加谷胱甘肽对黄颡鱼幼鱼组织谷胱甘肽含量、免疫及抗氧化性能的影响

研究旨在探讨饲料中添加还原型谷胱甘肽(Glutathione, GSH)对黄颡鱼幼鱼(Pelteobagrus fulvidraco)组织谷胱甘肽含量、免疫及抗氧化性能的影响。选用初始体重为(1.32±0.01) g的黄颡鱼800尾, 随机分为5组, 每组4个重复, 每个重复40 尾鱼, 分别投喂基础饲料和添加100、300、500和700 mg/kg GSH的试验饲料, 饲养56d后采样分析, 并采用氯化铵进行96h氨氮应激试验。结果表明: 除100 mg/kg组外, 饲料中添加GSH显著提高黄颡鱼肝脏、血清GSH含量(P<0.05), 当GSH添加量≥300 mg/kg时, 肝脏和血清GSH含量均呈现稳定状态。随着饲料中谷胱甘肽水平的增加, 血清免疫和肝脏抗氧化指标均呈现先升高后降低的趋势, 其中300和500 mg/kg组溶菌酶与碱性磷酸酶活性、300 mg/kg组免疫球蛋白M与补体4含量、500 mg/kg组酸性磷酸酶活性与对照组相比显著升高(P<0.05)。与对照组和700 mg/kg组相比, 300 mg/kg组肝脏超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化酶活性和总抗氧化能力与血清超氧化物歧化酶、谷胱甘肽过氧化酶活性均显著高升高(P<0.05); 且300 mg/kg组血清丙二醛含量显著降低(P<0.05)。氨氮应激96h时, 与对照组相比, 300 mg/kg组肝脏和血清超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化酶活性力均显著升高(P<0.05), 且300 mg/kg组血清丙二醛含量显著降低(P<0.05)。由此可见, 饲料中添加谷胱甘肽能提高黄颡鱼幼鱼组织谷胱甘肽含量、免疫及抗氧化性能, 其中以300—500 mg/kg为宜。     

Capsiate improves glucose metabolism by improving insulin sensitivity better than capsaicin in diabetic rats

Red peppers and red pepper paste are reported to have anti-obesity, analgesic and anti-inflammatory effects in animals and humans due to the capsaicin in red pepper. We investigated whether consuming capsaicin and capsiate, a nonpungent capsaicin analogue, modifies glucose-stimulated insulin secretion, pancreatic β-cell survival and insulin sensitivity in 90% pancreatectomized (Px) diabetic rats, a moderate and non-obese type 2 diabetic animal model. Px diabetic rats were divided into 3 treatment groups: 1) capsaicin (Px-CPA), 2) capsiate (Px-CPI) or 3) dextrose (Px-CON) and provided high fat diets (40 energy % fat) containing assigned components (0.025% capsaicin, capsiate, or dextrose) for 8 weeks. Both capsaicin and capsiate reduced body weight gain, visceral fat accumulation, serum leptin levels and improved glucose tolerance without modulating energy intake in diabetic rats. In comparison to the control, both capsaicin and capsiate potentiated first and second and phase insulin secretion during hyperglycemic clamp. Both also increased β-cell mass by increasing proliferation and decreasing apoptosis of β-cells by potentiating insulin/IGF-1 signaling. However, only capsiate enhanced hepatic insulin sensitivity during euglycemic hyperinuslinemic clamp. Capsiate reduced hepatic glucose output and increased triglyceride accumulation in the hyperinsulinemic state and capsiate alone significantly increased glycogen storage. This was related to enhanced pAkt→PEPCK and pAMPK signaling. Capsaicin and capsiate reduced triglyceride storage through activating pAMPK. In conclusion, capsaicin and capsiate improve glucose homeostasis but they differently enhance insulin sensitivity in the liver, insulin secretion patterns, and islet morphometry in diabetic rats. Capsiate has better anti-diabetic actions than capsaicin.