Anti-hyperglycemic Effect of Bilberry, Blackberry and Mulberry Ultrasonic Extracts on Diabetic Rats

Small fruits like bilberry, blackberry and mulberry are rich sources of anthocyanins and other phenols, compounds with a certified antioxidant activity and spectacular effects in some chronic diseases. Romanian bilberry, blackberry and mulberry extracts were tested as anti-hyperglycemic agents on diabetic rats. Anthocyanins extraction was carried out with 80 % acidified ethanol in ultrasonically conditions at 23?±?2 °C and 40 kHz. Monomeric anthocyanins content was determined by pH differential method and varied between 1200 and 2800 mg/L. The analyses of anthocyanins were achieved using high performance liquid chromatography and mass spectrometry. Phenolics content was determined by Folin-Ciocalteu procedure and values varied between 2320 and 4250 mg/L gallic acid. Antioxidant activities of extracts were estimated by DPPH scavenging method and the values varied between 8 and 16 miliequivalents Trolox. In order to evaluate the toxicology of the extracts, the heavy metals concentration and pesticides content were analyzed. The extracts were administrated to diabetic rats in drinking water for five weeks. The administration of bilberry extract offered no satisfactory results. Treatment with blackberry extract determined a significant decrease of glucose level from 360 to about 270 mg/dL (p?<?0.05). The mulberry extract administration determined a significant decrease of glucose level from 252 mg/dL at the start day to 155 mg/dL at the final of experiment (p?<?0.05).     

Insulin Secretagogue,Alpha-glucosidase and Antioxidant Activity of Some Selected Spices in Streptozotocin-induced Diabetic Rats

Spices are extensively used to enhance the taste and flavor of foods and are known to possess several medicinal properties. Myristica fragrans, Parmelia perlata, Illicium verum, Trachyspermum copticum and Myristica malabarica, the commonly used spices in India were assessed for antidiabetic activity in streptozotocin induced diabetic rats. In the in vitro insulin secretion studies on isolated islets of Langerhans, M. fragrans, T. copticum and M. malabarica showed dose dependent insulin secretion. At 1 mg/ml, P. perlata showed significant in vitro alpha-glucosidase inhibitory activity with IC₅₀ value of 0.14 mg/ml followed by M. malabarica (0.64 mg/ml), I. verum (0.67 mg/ml), M. fragrans (0.85 mg/ml) and T. copticum (0.92 mg/ml). The DPPH free radical scavenging activity of the extracts at a concentration of 1 mg/ml was as M. malabarica (90.45%), M. fragrans (89.89%), I. verum (87.22%), P. perlata (76.70%) and T. copticum (38.14%). P. perlata showed the highest phenolic content (i.e., 118.5 mg gallic acid equivalents/g) followed by M. malabarica (84.13 mg gallic acid equivalents/g). M. malabarica showed the highest flavonoid content (i.e., 38.35 mg quercetin equivalents/g). Regular use of these spices may prevent postprandial rise in glucose levels through inhibition of intestinal alpha-glucosidase and may maintain blood glucose level through insulin secretagogue action.     

Antihyperglycemic,Antioxidant and Antiglycation Activities of Mulberry Leaf Extract in Streptozotocin-Induced Chronic Diabetic Rats

In Thailand, beverages containing mulberry leaf (Morus alba L.) are believed to promote good health, especially in people with diabetes. We examined the effects of long-term administration of an ethanolic extract of mulberry leaf (MA) on blood glucose, oxidative damage, and glycation in streptozotocin-induced diabetic rats. Daily administration of 1 g/kg MA for six weeks decreased blood glucose by 22%, which was comparable to the effect of 4 U/kg insulin. Lipid peroxidation, measured as malondialdehyde and lipid hydroperoxide concentrations (3.50 ± 0.33 and 3.76 ± 0.18 μM, respectively) decreased significantly (P < 0.05) compared to nontreated control diabetic rats (8.19 ± 0.45 and 7.50 ± 0.46 μM, respectively). Hemoglobin A_1C, a biomarker for chronic exposure to high concentration of glucose, was also significantly decreased in the MA-treated group (6.78 ± 0.30%) in comparison to untreated group (9.02 ± 0.30%). The IC₅₀ of in vitro antiglycation and free radical scavenging activities of MA were 16.4 ± 5.6 μg/ml and 61.7 ± 2.1 μg/ml, respectively. These findings support that long-term administration of MA has antihyperglycemic, antioxidant and antiglycation effects in chronic diabetic rats, which may be beneficial as food supplement for diabetics.     

香蕉茎杆纤维提取加工设备的结构改进

通过改进切割破片机的关键部件切割刀具结构和采用不切割茎杆芯部的工艺方案等,使设备功耗和切割阻力大大减少,解决了茎杆撕裂、折断和腐烂茎杆加工问题,大大提高了适应性;通过增加排渣槽上方侧板、刀轮罩内表面横板,增大刀轮罩与刀轮的间隙和增设刀轮罩两端消声孔等改进设计,使刮麻机喂料口风速降低约90.8%,空载噪声降低约6 dB(A),大大减少了茎杆渣飞溅现象,改善了喂料和工作条件,提高了加工效率。     

普洱茶提取物对自发性高血压大鼠降压研究

采用自发高血压大鼠(SHR)进行普洱茶提取物降压功效的研究.给予普洱茶提取物0.25、0.5、1.0、2.0 g/kg灌胃4周,观察动物的血压、心率、体重变化.结果显示,以普洱茶提取物1.0 g/kg和2.0 g/kg灌胃4周,对动物的平均动脉压、收缩压和舒张压均有降低作用,与模型组间存在显著差异(P＜0.01).普洱茶提取物0.25 g/kg和0.5 g/kg组动物血压较模型组没有显著性改变.普洱茶提取物2.0 g/kg可提高动物的心率,有抑制其体重增长的趋势;其他剂量组动物的心率及体重增长均无显著变化.研究表明,普洱茶提取物对自发高血压大鼠具有降压作用,且具有剂量依赖性.     

The Protective Effect of Fucoidan in Rats with Streptozotocin-Induced Diabetic Nephropathy

Diabetic nephropathy (DN) has long been recognized as the leading cause of end-stage renal disease, but the efficacy of available strategies for the prevention of DN remains poor. The aim of this study was to investigate the possible beneficial effects of fucoidan (FPS) in streptozotocin (STZ)-induced diabetes in rats. Wistar rats were made diabetic by injection of STZ after removal of the right kidney. FPS was administered to these diabetic rats for 10 weeks. Body weight, physical activity, renal function, and renal morphometry were measured after 10 weeks of treatment. In the FPS-treated group, the levels of blood glucose, BUN, Ccr and Ucr decreased significantly, and microalbumin, serum insulin and the β2-MG content increased significantly. Moreover, the FPS-treated group showed improvements in renal morphometry. In summary, FPS can ameliorate the metabolic abnormalities of diabetic rats and delay the progression of diabetic renal complications.     

乌龙茶多糖对糖尿病大鼠肝肾抗氧化功能及组织形态的影响

利用链脲佐菌素(STZ)复制糖尿病大鼠模型,研究乌龙茶多糖对糖尿病大鼠肝肾抗氧化功能和组织形态变化的影响。结果表明,糖尿病大鼠灌胃乌龙茶多糖4周后,肝肾SOD和GSHPX活性明显提高,MDA含量显著下降,抗氧化能力增强;茶多糖对糖尿病大鼠肝肾组织有保护作用。     

Antioxidant and Antiglycative Potential of Ethyl Acetate Fraction of Psidium guajava Leaf Extract in Streptozotocin-Induced Diabetic Rats

Hyperglycemia causes increased protein glycation and the formation of early glycation products and advanced glycation end products (AGEs) which are major factors responsible for the complications associated with diabetes. The aim of the present study was to investigate the antioxidant as well as antiglycative potential of ethyl acetate fraction of guava leaves. Oral administration of the extract at different doses showed a significant decrease in blood glucose level. It also showed an improved antioxidant potential as evidenced by decreased lipid peroxidation and a significant increase in the activity of various antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase. Glycated hemoglobin as well as fructosamine which are indicators of glycation was also reduced significantly in treated groups when compared to diabetic control. In vitro studies also support the antioxidant as well as antiglycative potential of guava leaves.     

香蕉果实RNA提取方法的改进和比较

通过对几种不同的香蕉果实RNA提取方法的改进和比较,发现CTAB法是最有效、最简单和最经济的方法之一.该方法提取出来的RNA可以用来做cDNA合成和建立文库等分子生物学操作.     

Protective Effect of Potato Peel Powder in Ameliorating Oxidative Stress in Streptozotocin Diabetic Rats

The potential of dietary potato peel (PP) powder in ameliorating oxidative stress (OS) and hyperglycemia was investigated in streptozotocin (STZ)-induced diabetic rats. In a 4-week feeding trial, incorporation of potato peel powder (5 and 10%) in the diet of diabetic rats was found to significantly reduce the plasma glucose level and also reduce drastically the polyuria of STZ diabetic rats. The total food intake was significantly reduced in the diabetic rats fed 10% PP powder compared to the control diabetic rats. However, the body weight gain over 28 days was nearly four times greater in PP powder supplemented diabetic rats (both at 5 and 10%) compared to the control diabetic rats. PP powder in the diet also decreased the elevated activities of serum transaminases (ALT and AST) and nearly normalized the hepatic MDA and GSH levels as well as the activities of specific antioxidant enzymes in liver of diabetic rats. The result of these studies clearly establishes the modulatory propensity of PP against diabetes induced alterations. Considering that potato peels are discarded as waste and not effectively utilized, these results suggest the possibility that PP waste could be effectively used as an ingredient in health and functional food to ameliorate certain disease states such as diabetes.     

Antihyperglycemic Effects of <Emphasis Type="Italic">Platycodon grandiflorum</Emphasis> (Jacq.) A. DC. Extract on Streptozotocin-induced Diabetic Mice

The root of Platycodon grandiflorum (Jacq.) A. DC has been reported to have a wide range of health benefits in oriental food. This study examined the hypoglycemic effects of Platycodon grandiflorum (Jacq.) A. DC aqueous-ethanol extract (PGE) in streptozotocin (STZ) -induced diabetic ICR mice (STZ diabetic mice) for the first time. The effects of PGE on blood glucose, plasma insulin levels and body weight were investigated. A significant decrease in blood glucose levels was observed after single administration of PGE. Furthermore, Glibenclamide and PGE significantly suppressed the rise in blood glucose after 30 min in the acute glucose tolerance test. Treatment with glibenclamide and PGE resulted in a reduction in blood glucose levels from the 2nd week, and this reduction was maintained until the 4th week of treatment. The body weight changed slightly in glibenclamide and PGE treated mice in comparison with the STZ control group. Plasma insulin levels were increased with glibenclamide treatment in STZ diabetic mice, whereas such effect was not observed with PGE. These results indicated that PGE could induce hypoglycemic effects without stimulating insulin secretion.     

高粱不同组织浸提液对小麦幼苗的化感作用

为了给小麦合理轮作倒茬提供参考依据,研究了高粱不同组织的水浸提液对小麦幼苗生长的化感作用.结果表明,高粱秆、穗、叶的水浸提液对小麦幼苗的苗高和根长均有极强的化感作用,浸提液在低浓度时促进小麦生长,高浓度抑制小麦生长,且对根的化感作用大于对地上部的化感作用.高浓度高粱浸提液降低了小麦的根系活力和叶片可溶性蛋白含量,提高了小麦叶片的丙二醛(MDA)含量;小麦叶片的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)等酶活性均显著下降.综合来看,高粱不同组织水浸提液对小麦的化感作用表现为秆＞穗＞叶.     

南瓜根系及根部土壤水浸液化感作用研究

以黄瓜、西瓜作受体材料,研究南瓜根系及根部土壤水浸液的化感作用。结果表明,南瓜根系及根部土壤水浸液对受体种子萌发率、萌发指数、幼苗根长、苗高和苗干重存在化感促进或抑制效应。对指标进行综合效应分析,发现南瓜根系及根部土壤水浸液化感作用呈现浓度效应及受体差异性,一定浓度水浸液处理对受体种子萌发阶段、幼苗生长阶段及整体生长有促进作用,但西瓜较黄瓜对浓度敏感,0.02 g/mL南瓜根系及根部土壤水浸液对黄瓜化感促进强度最大,0.04 g/mL处理下,表现为化感促进强度降低或微弱抑制作用;0.02和0.04 g/mL南瓜根系水浸液及0.04 g/mL根部土壤水浸液对西瓜则表现为强烈抑制现象。     

转基因香蕉植株对根际土壤微生物的影响

通过对遗传转化技术获得的转基因香蕉植株和对照植株根际土壤微生物的培养实验,结果表明,转基因植株和对照植株对根际土壤中细菌、真菌、放线菌种群均没有影响.土壤微生物在BIOLOG GN微平板上的ELISA反应结果表明,转基因香蕉植株根际土壤微生物的每孔颜色平均变化率(Average Well Color Devel-opment,AWCD)的变化曲线和对照AWCD的变化曲线接近吻合.进一步对72 h的土壤微生物群落功能多样性的5种指数作方差分析,结果表明,5种指数和对照没有显著差异.实验结果表明转基因香蕉植株和对照植株对根际土壤微生物群落的结构和功能多样性没有产生影响.     

假臭草浸提液对玉米根系活力的影响

对不同假臭草浸提液处理的玉米幼苗根系活力进行测定,并通过生物活性作用响应指数RI(response index)研究假臭草浸提液的化感作用强度。结果表明,在假臭草浸提液浓度分别为0.0125g(FW)/mL(A1)、0.025g(FW)/mL(A2)、0.05g(FW)/mL(A3)时,对玉米根系影响的RI平均值分别为-0.1675、-0.3033、-0.4706,假臭草浸提液浓度越大,RI值随之越大;假臭草新鲜茎叶(B1)、新鲜根系(B2)、烘干茎叶(B3)及烘干根系(B4)组织浸提液对玉米根系影响RI平均值分别为-0.5251、-0.2651、-0.2379、-0.2272;不同浓度及不同组织浸提液交互作用间,在0.05g(FW)/mL(A3)浓度下,假臭草新鲜茎叶组织对玉米根系影响的RI平均绝对值最大(RI=-0.8949),在0.0125g(FW)/mL(A1)浓度下,假臭草新鲜茎叶组织对玉米根系影响的RI平均绝对值最小(RI=-0.1252)。假臭草浸提液具有一定的化感作用,浓度越高,其化感作用越强,茎叶组织浸提液的化感作用比根系浸提液的强,新鲜假臭草组织的化感作用比烘干组织的强。     

40%乙烯利水剂催熟对香蕉品质的影响

以七成熟的威廉斯香蕉为试材,采用两种不同稀释浓度(1 000和1 500 mg/kg)的40%乙烯利溶液进行浸泡处理,分别贮存于16和22℃的室内进行催熟,并定期对香蕉进行取样,检测香蕉各感官及生理指标的变化。结果表明,不同处理浓度的乙烯利催熟效果无显著差异,样品均成熟且色泽光亮,营养损失不大。22℃条件下催熟的香蕉比16℃条件下催熟的香蕉成熟速度快,食用品质更佳,有利于采摘后快速投放市场。综合考虑乙烯利残留量的安全问题以及催熟成本,建议采用1 000 mg/ kg的乙烯利溶液在常温下(22℃)催熟。     

Beneficial Effect of S-allylcysteine (SAC) on Blood Glucose and Pancreatic Antioxidant System in Streptozotocin Diabetic Rats

The aim of the present study was to evaluate the possible protective effects of S-allyl cysteine (SAC) on the antioxidant defense system of pancreas in streptozotocin(STZ) induced diabetes in rats. The levels of blood glucose and TBARS in plasma and pancreas were estimated in control and experimental groups of rats. To assess the changes in the cellular antioxidant defense system, the level of reduced glutathione in plasma and pancreas and activities of superoxide dismutase and catalase were assayed in pancreatic tissue homogenate. The levels of glucose, TBARS and enzymatic antioxidants were altered in diabetic rats. These alterations were reverted back to near control levels after the treatment of SAC. The antidiabetic and antioxidant effect of SAC was compared with glyclazide, a well-known hypoglycemic drug. These findings suggest that SAC treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress.     

Antidiabetic Activity of Differently Regioselective Chitosan Sulfates in Alloxan-Induced Diabetic Rats

The present study investigated and compared the hypoglycemic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats. Compared with the normal control rats, significantly higher blood glucose levels were observed in the alloxan-induced diabetic rats. The differently regioselective chitosan sulfates exhibited hypoglycemic activities at different doses and intervals, especially 3-O-sulfochitosan (3-S). The major results are as follows. First, 3,6-di-O-sulfochitosan and 3-O-sulfochitosan exhibited more significant hypoglycemic activities than 2-N-3, 6-di-O-sulfochitosan and 6-O-sulfochitosan. Moreover, 3-S-treated rats showed a more significant reduction of blood glucose levels than those treated by 3,6-di-O-sulfochitosan. These results indicated that –OSO₃⁻ at the C3-position of chitosan is a key active site. Second, 3-S significantly reduced the blood glucose levels and regulated the glucose tolerance effect in the experimental rats. Third, treatment with 3-S significantly increased the plasma insulin levels in the experimental diabetic rats. A noticeable hypoglycemic activity of 3-S in the alloxan-induced diabetic rats was shown. Clinical trials are required in the future to confirm the utility of 3-S.     

Antioxidant Effect of Dietary Supplement Withania somnifera L. Reduce Blood Glucose Levels in Alloxan-Induced Diabetic Rats

The phenolic compounds and flavonoids were determined from the extracts of Withania somnifera root (WSREt) and leaf (WSLEt). The WSREt has 28.26 mg/g total phenolic compounds and 17.32 mg/g flavonoids, whereas WSLEt has 5.4 mg/g total phenolic compounds and 5.1 mg/g flavonoids. The WSREt, WSLEt and glibenclamide were orally administered daily to diabetic rats for 8 weeks. After the treatment, the levels of urine sugar, blood glucose, liver glycogen, and antioxidants like vitamin C and E in plasma and superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in liver, kidney and heart were determined. Diabetic rats showed a significant (p < 0.05) elevation in glucose and TBARS and a significant (p < 0.05) reduction in glycogen, vitamin C and E, SOD, CAT, GPx, GST, and GSH levels when compared to normal control rats. Administration of WSREt, WSLEt and glibenclamide to diabetic rats restored the levels to normal. In the light of aforesaid facts, it is suggested that the presence of phenolic compounds including flavonoids in W. somnifera root and leaf extracts and their antioxidant activity may play a vital role in reduction of blood glucose level in alloxan-induced diabetic rats.