Anti-stress activity of Sargassum polycystum extracts using a cold restraint stress model

Food Science and Biotechnology - Anti-stress effects of polyphenol extracts of Sargassum polycystum were evaluated. Polyphenol extracts of S. polycystum and diazepam were compared for anti-stress...     

全缘马尾藻提取物对酵母膏诱导小鼠高尿酸血症的拮抗效应

本文主要研究全缘马尾藻在不同乙醇浓度(0%、25%、50%、75%)提取物对模型小鼠高尿酸血症的拮抗作用。利用酵母膏灌胃法建立小鼠高尿酸血症模型,测定小鼠血清尿酸(UA)水平,以及肝脏中黄嘌呤氧化酶(XOD)和腺苷脱氨酶(ADA)活性,并计算小鼠肝脏、肾脏器官指数,HE染色观察其肾脏组织病理学变化。结果表明,与空白组相比,酵母膏能极显著升高小鼠血清尿酸水平(p<0.01)、肝脏XOD及ADA活性(p<0.01)。与模型组相比,全缘马尾藻各醇浓度提取物均能降低血清UA水平、肝脏XOD及ADA活性,其中50%醇提取物组对降低血清UA水平具有极显著性意义(p<0.01),光镜下可见,治疗组多数小鼠肾小球、肾小管结构恢复正常。总体而言,全缘马尾藻提取物对酵母膏致小鼠高尿酸血症具有一定程度的缓解作用,其机制与尿酸代谢有关。      

Immune modulation in suckling rat pups by a growth factor extract derived from milk whey

Oral tolerance to foreign enteral antigens is not fully developed in early neonatal life. Epidemiological evidence supports a role for maternal milk in the development of immune responses, including oral tolerance. Formula fed infants have an increased susceptibility to food allergy and the later development of autoimmune disease. This may relate to the lack in infant formula of growth factors found in maternal milk. Bovine milk contains proteins, growth factors and cytokines. Various studies have outlined the immune modulating potential of bovine milk-derived products. Fractionated whey extracts have therapeutic potential in disease states where there is an excessive inflammatory reaction, and disease preventive potential for infants who are not breast-fed. We have shown that daily oral administration of a growth factor-enriched fraction from milk whey to naturally suckling rat pups between days 4-9 postnatal can down-regulate immune activation to a specific orally administered food antigen, ovalbumin, assessed by lymphocyte proliferation. In addition, non-specific down-regulation in the intestine was observed as assessed by the expression of MHC I. Treatment of rat pups with whey extract at the time of oral sensitisation to ovalbumin also resulted in an increased secretion of TGF-beta into the culture supernatant of spleen cells incubated with specific antigen. TGF-beta is an immuno-down-regulatory cytokine involved in tolerance induction. Immune modulation by extracts derived from milk whey could be of potential benefit for formula-fed and pre-term infants in reducing susceptibility to inappropriate activation to food antigens.     

Beneficial effects of sulfated polysaccharides from Sargassum wightii against mitochondrial alterations induced by Cyclosporine A in rat kidney

Sulfated polysaccharides from marine seaweeds are receiving continuous attention owing to their wide therapeutic applications and are known to inhibit free radical generation. It has been well known that mitochondria are the major sources as well as the target of free radicals. The renal tubules have high density of mitochondria and therefore show structural and functional defects in acute renal failure. Hence, the present study is designed to appraise the mitochondrial status during Cyclosporine A (CsA)-induced nephrotoxicity and the effect of sulfated polysaccharides over it. Sulfated polysaccharides (5 mg/kg body weight, subcutaneously) treatment significantly prevented the CsA-induced (25 mg/kg body weight, orally) mitochondrial damage. CsA-induced mitochondrial oxidative stress in rat kidney was evident from increased reactive oxygen species level, decreased antioxidant defense system, coupled with enhanced lipid peroxidation. Further, the activities of tricarboxylic acid cycle and electron transport chain enzymes were decreased in CsA-induced rats, along with a significant increase in the activities of urinary enzymes, thus indicating renal tubular injury. Ultrastructural changes were also in accord with the above aberrations. The above abnormalities were favorably modulated by sulfated polysaccharides supplementation, thus highlighting the significance of sulfated polysaccharides in preventing the renal mitochondrial dysfunction allied with CsA-provoked nephrotoxicity.     

槟榔提取物对小鼠免疫功能及肝脏抗氧化酶的影响

以三种品牌槟榔水提取液和稀磷酸提取物为对象,测定提取物对小白鼠体重、免疫功能及抗氧化酶活性的影响。免疫评价指标包括脾脏指数、胸腺指数以及免疫球蛋白Ig A、Ig G和Ig M含量,抗氧化酶指标包括SOD和CAT活性。结果表明,三种槟榔均能显著提高小白鼠体重(p0.01),对胸腺指数、免疫球蛋白影响不显著,仅一个品牌槟榔稀磷酸提取液90 d时显著降低脾脏指数(p0.05)和CAT活性(p0.05)。槟榔提取液90 d内对小鼠具有促进食欲、增加体重的作用,对其免疫功能和抗氧化酶活性总体没有明显影响。     

鹿茸醇提物对小鼠学习记忆功能的影响

目的:研究鹿茸醇提物(AVAE)对小鼠学习记忆能力的影响。方法:156只昆明种雄性小鼠分成空白组(12只小鼠,灌胃生理盐水)、记忆获取阶段组、记忆巩固阶段组和记忆再现阶段组(每组48只小鼠),各阶段组中的高、中、低剂量组每天每只小鼠分别灌胃鹿茸乙醇提取物的干粉量为1kg/(kg·d)、0.5kg/(kg·d)和0.1kg/(kg·d)。灌胃30d,测定各个记忆阶段小鼠跳台实验的潜伏期及错误次数、水迷宫实验的游出时间及错误次数和小鼠大脑内的SOD酶活力及MDA含量。结果:鹿茸醇提物能明显延长各个阶段小鼠跳台实验的潜伏期(P<0.01)并减少错误次数(P<0.01);缩短小鼠水迷宫实验的游出时间及减少错误次数(P<0.01,P<0.05);提高小鼠脑内SOD酶活力(P<0.01,P<0.05);降低小鼠脑内MDA含量(p<0.01,p<0.05)。结论:鹿茸醇提物对小鼠学习记忆障碍有明显的改善作用。      

毛细管气相色谱法测定鼠尾藻中多不饱和脂肪酸

采用毛细管气相色谱法对鼠海藻中多不饱和脂肪酸进行测定,采用DB-WAX（60m×0.32mm×0.25μm）色谱柱,进样口温度250℃,柱温230℃,恒温20min,流速1.7mL·min-1,FID检测器,检测器温度300℃。方法相对标准偏差0.524%～1.297%,回收率97.7%～99.8%,各成分的线性相关系数r2>0.99。方法简便,具有较高的准确度和精确度,可应用于藻类分析。      

Effects of dietary fibre extracts on calcium absorption in the rat

The effects on calcium absorption of several fibre extracts (which differed greatly in their chemical compositions, phytate concentrations, and proportions of soluble and insoluble fibre) and of phytate, as sodium phytate, were investigated in rats. Samples of fibre from apple, orange, pea, sugarbeet, barley and wheat were obtained from Sofalia (France). Calcium absorption (using a ⁴⁷Ca tracer method) in 9-week-old rats from a purified diet, containing fibre at a level of 50 g/kg, was reduced by wheat and wheat-TDF fibre preparations and was unaffected by apple, orange, pea, sugarbeet, barley, pectin and guar gum, compared to the cellulose-containing diet. Calcium absorption was also reduced by increasing phytate concentration in the range 0 to 30 mmol/kg diet. Overall, the results suggest that calcium absorption is not affected by fibre components per se, (i.e. indigestible polysaccharides) and that the reduction in calcium absorption observed with wheat and wheat-TDF fibres is due to their phytate contents.     

Antibacterial effect of water-soluble tea extracts on foodborne pathogens in laboratory medium and in a food model

The microbial inhibition of foodborne pathogens was determined in brain heart infusion broth with 10% (wt/vol) water-soluble extracts of green, jasmine, black, dungglre, and oolong tea against Escherichia coli O157:H7, Salmonella enterica serovar Enteritidis, Listeria monocytogenes, and Staphylococcus aureus. The mixed culture (approximately 6.0 log CFU/ml), which was composed of the four pathogens, was inoculated into brain heart infusion broth with and without tea extracts. After incubation at 35 degrees C for 0, 1, 3, and 5 days, proper dilution of each sample was spiral plated on each selective agar. Viable cell counts were performed after incubation at 35 degrees C for 24 to 36 h. Green, jasmine, and black tea exhibited an approximately 5.0 log suppression of S. aureus compared with the control from days 1 to 5. Green and jasmine tea also suppressed the growth of L. monocytogenes by approximately 3.0 log CFU/ml on day 5. In contrast, no tea extracts inactivated E. coli O157:H7 and Salmonella Enteritidis. Based on the result in liquid medium, green and jasmine teas of 0.1% (vol/wt) were individually evaluated for their antimicrobial activity against L. monocytogenes and S. aureus in a food model (ground beef) stored at 7 degrees C for 0, 1, 3, 5, and 7 days. Viable cell counts of total bacteria, L. monocytogenes, and S. aureus in ground beef were not significantly different among green and jasmine tea and the control.     

Dietary supplementation with Ceriporia lacerata improves learning and memory in a scopolamine-induced amnesia mouse model

Food Science and Biotechnology - Ceriporia lacerata (CL) is a species of white rot fungi. In this study, we have examined the beneficial effect of CL on scopolamine-induced memory impairment in...