广叶绣球菌超微粉抗肿瘤作用研究

广叶绣球菌(荷仙菇-H)是近年来新培养的一种食药用真菌,属担子菌门、多孔菌目、绣球菌科、绣球菌属。本文对其超微粉的抗肿瘤作用及机制进行了研究。建立了H22荷瘤小鼠肿瘤移植模型,设置空白对照组、模型组、环磷酰胺阳性组、广叶绣球菌超微粉高、中、低3个剂量组(1 000,500和100mg/kg),连续给予相应药物10d,计算H22荷瘤小鼠的抑瘤率、体质量、胸腺指数、脾脏指数以及肝脏指数,对各组小鼠的瘤块进行组织病理学研究,并对血清中的SOD和IFN-γ含量进行了测定。结果发现广叶绣球菌超微粉3个给药组的抑瘤率均大于40%,高剂量组抑瘤率最高为54%;可增加小鼠体质量;提高胸腺指数、脾脏指数和肝脏指数;给药组SOD值均高于模型组,说明广叶绣球菌超微粉可以起到抗氧化的作用;给药组IFN-γ值均高于模型组,给药组VEGF值均低于模型组,说明广叶绣球菌超微粉能够提高机体免疫能力。因此,广叶绣球菌超微粉的抗肿瘤作用明显,可能是通过改善机体免疫功能和抗氧化能力,抑制了肿瘤细胞,达到抗肿瘤的功效。     

蜜蜂巢脾提取物对小鼠免疫调节作用的影响

本研究旨在从体重、脏器/体重比值、体液免疫、细胞免疫和NK细胞活性等研究蜜蜂巢脾提取物对小鼠免疫调节作用的影响。采用160只雄性昆明种小鼠为研究对象,按体重随机分4批,每批4个组别,分别为阴性对照组、蜜蜂巢脾提取物高、中、低剂量组,测定免疫学指标。本研究结果显示,小鼠体重增长正常,各组小鼠脏器/体重比值、胸腺/体重比值无明显变化,均无显著性差异。高、中剂量组的小鼠脾淋巴细胞转化和血清溶血素高于阴性对照组且有显著性差异(P0.05),三个剂量组比阴性对照组的校正廓清指数α和NK细胞活性有显著差异(P0.05)。由此可见,蜜蜂巢脾提取物能显著提高小鼠的体液免疫和细胞免疫能力及抗氧化活性。     

不同“桑黄”类真菌水提取物的抗肿瘤活性研究

用H22荷瘤小鼠对6种"桑黄"类真菌的水提取物进行了抗肿瘤活性研究。结果表明,除鲍姆木层孔菌水提取物低剂量组外,粗毛纤孔菌、椭圆嗜蓝孢孔菌、山野木层孔菌的水提取物高、低剂量组以及火木层孔菌、鲍姆木孔菌、瓦尼木层孔菌的水提取物高剂量组均具有显著抑瘤作用,抑瘤率均大于40%,其中;椭圆嗜蓝孢孔菌水提取物高剂量组(1 000 mg/kg)的抑瘤效果最佳。与阳性组和生理盐水组相比,粗毛纤孔菌高剂量组小鼠的胸腺指数均有极显著性差异(P0.01),其余各组小鼠胸腺指数无显著性差异。6种"桑黄"类真菌水提取物均对提高小鼠肿瘤细胞中Bax的表达起到了促进作用;对Bcl-2的表达起到了抑制作用。     

硬毛粗盖孔菌子实体提取物抑制H_(22)荷瘤小鼠肿瘤活性研究

本文对硬毛粗盖孔菌子实体不同提取物的抗肿瘤活性进行筛选。通过建立H_(22)荷瘤小鼠肿瘤移植模型,研究硬毛粗盖孔菌子实体的石油醚提取物、二氯甲烷提取物、乙酸乙酯提取物、甲醇提取物以及水提取物等5种提取物的高、中、低剂量组对H_(22)荷瘤小鼠的抑瘤作用,并对其H_(22)荷瘤小鼠的抑瘤率、体质量、胸腺指数、脾脏指数、肝脏指数、肾脏指数进行了考察。对小鼠肿瘤、脾脏、肾脏进行了组织病理学检查,对血清中的细胞因子IL‐2、IL‐4、IFN‐γ及TNF‐α的含量进行测定。结果表明:各组分均有抑瘤效果,其中乙酸乙酯提取物中剂量组(1 000mg/kg)抑瘤效果最佳,与阴性对照组比较有极显著差异(P0.01),并且这组的H_(22)荷瘤小鼠血清中白介素‐2的含量显著增加,同时肿瘤细胞通过HE染色后,可观察到出现坏死面积增大,与抑制肿瘤活性具有相关性。     

番石榴叶提取物对高脂性肥胖小鼠的减肥降脂作用的研究

目的:研究番石榴叶提取物对小鼠肥胖模型的减肥、降脂作用。方法:①利用高脂饲料喂养,建立小鼠肥胖模型;②小鼠肥胖模型初步建立后,以体重、热量摄取、腹部脂肪系数、空腹血糖(FBG)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)为指标,通过普通饲料阴性组,阳性对照药非诺贝特给药组比较,探求番石榴叶提取物的减肥、降脂作用及其剂量依赖关系。结果:①与Nomal组比较,HFD组的小鼠体重、热量摄取、腹部脂肪系数、FBG、TG、TC、LDL-C显著增加;②给药后,3个剂量番石榴叶提取物组的小鼠体重、腹部脂肪系数、FBG、TG、TC、LDL-C均明显低于高脂饲料组,且呈显著或极显著差异,并与阳性对照组无明显差异;③3个剂量番石榴叶提取物组的减肥、降脂作用存在一定的效应-剂量关系,即LD组(50mg/Kg)MD组(100 mg/Kg)HD组(200 mg/Kg)。结论:番石榴叶60%乙醇提物对小鼠肥胖症和高脂血症有一定的预防和治疗作用,3个剂量组中HD组(200 mg/Kg)效果最好,可望开发为减肥降脂的纯天然药物。     

葡萄籽原花青素提取物对糖尿病小鼠血糖的影响

为了研究葡萄籽原花青素提取物(Grape Seed Proanthocyanidin Extracts,GSPE)对糖尿病小鼠的降血糖作用及其机制,本文中采用腹腔注射四氧嘧啶(ALX)构建糖尿病动物模型.造模成功后,将糖尿病小鼠分为模型对照组、格列本脲处理组、葡萄籽原花青素提取物低、中、高三个剂量(50、100、150 mg/kg)处理组,另设正常对照组.连续灌胃给药21天,每天一次,以糖尿病小鼠的体重、血清丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性胰岛素水平、空腹血糖值和糖耐量为测定指标,研究不同剂量葡萄籽原花青素提取物对糖尿病小鼠的降血糖作用及机制.结果显示原花青素高剂量组能促进体重增长,显著降低糖尿病小鼠的血糖水平和糖耐量(P＜0.01);同时降低糖尿病小鼠血清MDA水平,提高其SOD活性.通过本实验研究可以看出葡萄籽原花青素提取物具有较强的降血糖作用,降糖机制可能与其提高胰岛素水平和抗氧化能力有关.     

四季豆和淡豆豉提取物降血糖动物实验研究

目的：研究四季豆和淡豆豉提取物的降血糖作用,为开发辅助降血糖的保健食品提供实验依据。方法：设低、中、高三个四季豆和淡豆豉提取物受试样品组,1个纯水对照组、1个高血糖模型对照组,每组12只小鼠。3个剂量组分别给予0.14、0.28、0.83g/kg BW受试样品,相当于推荐日服量的5、10、30倍。用四氧嘧啶制备高血糖小鼠模型后,连续用受试样品30d后,观察其对高血糖模型小鼠和正常小鼠空腹血糖和糖耐量的影响。结果：受试样品在0.83g/kg BW剂量下,高剂量组的糖耐量值明显低于高血糖模型对照组（P＜0.05）;在0.14g/kg BW和0.83g/kg BW剂量下,低、高剂量组的空腹血糖值明显低于高血糖模型对照组（P＜0.01、P＜0.05）;同时受试样品对正常小鼠的空腹血糖没有明显影响（P＞0.05）。结论：四季豆和淡豆豉提取物对糖尿病小鼠的血糖具有辅助调节作用。     

蜜环菌粉正己烷提取物抗神经炎症研究

蜜环菌是一种药食兼用真菌,其提取物有多种药用价值,本文通过动物体内实验对其抗神经炎症作用进行探究。利用1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）建立了帕金森病小鼠模型,设置空白组、模型组、蜜环菌粉正己烷提取物高低剂量组（10mg/kg、20mg/kg）,连续灌胃给药12d,对小鼠体重、行为学指标、纹状体TH蛋白、Iba-1蛋白、iNOS酶活及相关mRNA表达进行探究。结果发现蜜环菌粉正己烷提取物组能缓解MPTP造模引起的体重减少,对小鼠行为迟缓有显著性改善,增加纹状体TH蛋白表达,抑制Iba-1蛋白过表达,同时对纹状体内炎症因子iNOS及相关mRNA表达有明显的抑制作用。因此,蜜环菌粉正己烷提取物有良好的抗神经炎症活性,可能是通过抑制小胶质细胞的过度激活,抑制iNOS酶活等途径发挥作用。     

纳米级南瓜肌醇提取物的制备及其降血糖作用研究

本文通过制备纳米级南瓜肌醇提取物(Nanoscale pumpkin inositol extract,NPIE),观察其对链脲佐菌素诱导的糖尿病模型C57小鼠的血糖调节作用,并与普通南瓜肌醇提取物(Common pumpkin inositol extract,CPIE)的降血糖作用比较。高、低剂量CPIE组和NPIE组分别灌胃500 mg/kg、250 mg/kg的CPIE和NPIE水溶液,阳性药组灌服250 mg/kg的盐酸二甲双胍水溶液,模型对照组灌服等体积的双蒸水,实验周期均为30 d。结果显示所制备的南瓜肌醇提取物含肌醇3.12%,多糖53.21%,其中NPIE粒度平均小于500 nm;经动物实验,各给药组对正常小鼠无明显急性降糖作用,对糖尿病小鼠体重也无影响;但NPIE高剂量组对糖尿病小鼠的随机血糖和空腹血糖均具有明显降低效果,并对其糖耐量有一定改善作用,整体降糖效果较阳性药物组略弱,较CPIE强。     

菠萝蜜低聚肽对γ射线辐照小鼠氧化损伤的保护作用

目的：探究菠萝蜜低聚肽（JOPs）对γ射线辐照导致小鼠氧化损伤的保护作用。方法：选取96只SPF级雌性BALB/c小鼠,按体重随机分为空白组、模型组、乳清蛋白组（0.40 g/kg·BW）及3个JOPs干预组（0.20、0.40、0.80 g/kg·BW）,每组随机分为2个亚组,8只/亚组。行灌胃干预第14 d除空白组外,小鼠接受60Co γ射线全身辐照,剂量3.5 Gy,剂量率1 Gy/min。两亚组分别在辐射后第3 d和第14 d检测小鼠血清和肝脏超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH Px）活性及丙二醛（MDA）水平。结果：辐照后第3 d及第14 d,相比空白组,模型组血清、肝脏SOD及GSH Px活性均显著降低,MDA水平均显著增高,JOPs各剂量组小鼠血清及肝脏MDA水平均显著低于模型组与乳清蛋白组;辐照后第3 d,相比模型组,JOPs各剂量组小鼠血清及肝脏SOD、GSH Px活性均显著增高,且高剂量组小鼠血清SOD活性及血清、肝脏GSH Px活性与中、高剂量组肝脏SOD活性均显著高于乳清蛋白组;辐照后第14 d,相比模型组,JOPs各剂量组小鼠血清及肝脏SOD、GSH Px活性均显著增高,且JOPs各剂量组小鼠血清SOD活性与高剂量组肝脏SOD、GSH Px活性均显著高于乳清蛋白组。结论： JOPs对γ射线辐照所致氧化损伤具有保护作用。     

西红花水提物对实验性糖尿病小鼠血糖水平的影响

目的：观察西红花水提物对链脲佐菌素（STZ）诱导的糖尿病小鼠血糖、血脂及胰腺组织的影响。方法：采用STZ （60 mg/kg）连续2 d腹腔注射建立糖尿病小鼠模型。将造模成功后的小鼠随机分为3组（n=10）：糖尿病模型（DM）组、西红花水提物（SE）组、阳性对照二甲双胍（MH）组。另取10只正常小鼠设为正常对照（NC）组。给药组每天灌胃1次,连续6周,模型组和正常对照组灌胃生理盐水。给药期间每周测定小鼠进食量、饮水量及体重,给药6周后测定空腹血糖（FBG）、口服糖耐量（OGTT）、糖化血清蛋白（GSP）、血清胰岛素（INS）和血脂等指标的变化情况;HE染色观察胰腺组织病理变化。结果：与NC组相比,DM组进食量、饮水量、线下曲线面积、FBG、GSP以及血脂中的总胆固醇（TC）均显著升高,空腹体重、血清胰岛素（INS）及高密度脂蛋白胆固醇（HDL-c）均显著降低;与DM组相比,SE组小鼠饮水量、FBG、线下曲线面积、TC显著降低,HDL-c以及INS显著升高。病理学显示DM组胰岛结构破坏、胰岛细胞数量明显减少、胰岛血管增生、形态不规则等变化,SE能明显修复受损胰腺组织。结论：SE对链脲佐菌素诱导的糖尿病小鼠有一定降血糖、降血脂作用,可以有效改善胰腺病变的情况,提示西红花可能用于糖尿病的防治。     

Antidiabetic potential of Caralluma europaea against alloxan-induced diabetes in mice

Medicinal plants play an important role in the management of diabetes mellitus especially in developing countries where resources are lacking. Herbal of natural origin, unlike the synthetic compounds, are more effective, safer and have less side effects. For continuing research on biological properties of Moroccan medicinal plants, the present work was undertaken to evaluate the potential and mechanism of the antidiabetic activity of the Caralluma europaea methanolic extract in alloxan-induced diabetic mice. A high-performance liquid chromatography technique (HPLC) was used to identify and quantify the major phenolic compounds in the methanolic extract. The in vitro antioxidant property was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging method, reducing power and ß-carotene-linoleic acid assays. The acute toxicity of the extract was evaluated by giving it orally to mice at single doses of 200, 500, 1000, 2000 mg/kg body weight. The antidiabetic effect was conducted on Swiss albino mice. Diabetes was induced with single intraperitonial injection of alloxan monohydrate (200 mg/kg body weight) and animals were treated with methanol extract at a dose of 250 mg/kg and 500 mg/kg body weight. The blood glucose levels were measured and histopathological analysis of pancreas was performed to evaluate alloxan-induced tissue injuries. The main phenols identified and quantified in the extract were ferulic acid, quercetine, 3,4 dihydroxybenzoic acid, rutin, epigallocatechin, and catechin. Ferulic acid was found to be the main phenolic compound ant its proportion was up to 52% of total phenolic compounds, followed by quercetin (36%). The result showed that methanol extract exhibited an antioxidant effect. Acute toxicity studies revealed that C. europaea extract was safe up 2000 mg/kg body weight and approximate LD₅₀ is more than 2000 mg/kg. Moreover, the methanol extract prevented the diabetogenic effect of alloxan and decreased significantly the blood glucose level (P < 0.001) in treated mice. Morphometric study of pancreas revealed that C. europaea extract protected significantly the islets of Langerhans against alloxan-induced tissue alterations.     

Nephro-protective effects of a ginger extract on cytosolic and mitochondrial enzymes against streptozotocin (STZ)-induced diabetic complications in rats

Diabetes is characterized by elevated blood glucose levels and disturbed homeostasis of metabolic enzymes in whole-body. This study aimed to investigate the effect of ginger administration on altered blood glucose levels, intra- and extra-mitochondrial enzymes and tissue injuries in streptozotocin (STZ)-induced diabetic rats. Wistar strain rats (n = 30) were equally divided into 5 groups: normal control (NC), ginger treated (Gt, 200 mg/kg b.w. orally/30 days), diabetic control (DC, 50 mg/kg b.w.), diabetic plus ginger treated (D + Gt) and diabetic plus glibenclamide treated (D + Gli) groups. We found highly elevated blood glucose levels in the diabetic group, and the glucose levels were significantly (P < 0.001) lowered by ginger administration. Activities of intra- and extra-mitochondrial enzymes such as glucose-6-phosphate dehydrogenase (G6PD), succinate dehydrogenase (SDH), malate dehydrogenase (MDH) and glutamate dehydrogenase (GDH) were significantly (P < 0.01) decreased in the kidneys of the diabetic rats, while this was significantly reversed by 30 days of ginger treatment. We also observed consistent renal tissue damages in the diabetic rats; however, these injuries recovered in the ginger-treated diabetic rats as shown in histopathological studies. In this study, we demonstrated that an ethanolic extract of ginger could lower the blood glucose levels as well as improve activities of intra- and extra-mitochondrial enzymes in diabetic rats. Our results suggest that ginger extracts could be used as a nephro-protective supplement particularly to reverse diabetic-induced complications.     

The effects of 13 wk of liraglutide treatment on endocrine and exocrine pancreas in male and female ZDF rats: a quantitative and qualitative analysis revealing no evidence of drug-induced pancreatitis

A possible association between glucagon-like peptide-1 (GLP-1) analogs and incidences of pancreatitis has been suggested based on clinical studies. In male and female diabetic Zucker diabetic fatty (ZDF) rats, we investigated the effects of continuous administration of liraglutide and exenatide on biochemical [lipase, pancreatic amylase (P-amylase)] and histopathological markers of pancreatitis. Male and female ZDF rats were dosed for 13 wk with liraglutide (0.4 or 1.0 mg·kg(-1)·day(-1) sc once daily) or exenatide (0.25 mg·kg(-1)·day(-1) sc, Alzet osmotic minipumps). P-amylase and lipase plasma activity were measured, and an extended histopathological and stereological (specific cell mass and proliferation rate) evaluation of the exocrine and the endocrine pancreas was performed. Expectedly, liraglutide and exenatide lowered blood glucose and Hb A(1c) in male and female ZDF rats, whereas β-cell mass and proliferation rate were increased with greatly improved blood glucose control. Whereas neither analog affected lipase activity, small increases in P-amylase activity were observed in animals treated with liraglutide and exenatide. However, concurrent or permanent increases in lipase and P-amylase activity were never observed. Triglycerides were lowered by both GLP-1 analogs. The qualitative histopathological findings did not reveal adverse effects of liraglutide. The findings were mainly minimal in severity and focal in distribution. Similarly, the quantitative stereological analyses revealed no effects of liraglutide or exenatide on overall pancreas weight or exocrine and duct cell mass or proliferation. The present study demonstrates that, in overtly diabetic male and female ZDF rats, prolonged exposure to GLP-1 receptor agonists does not affect biochemical or histopathological markers of pancreatitis, and whereas both exenatide and liraglutide increase β-cell mass, they have no effect on the exocrine pancreas. However, clinical outcome studies and studies using primate tissues and/or studies in nonhuman primates are needed to further assess human risk.     

Hypoglycemic activity of leaf organic extracts from Smallanthus sonchifolius: Constituents of the most active fractions

The aim of the present study was to determine the in vivo hypoglycemic activity of five organic extracts and enhydrin obtained from yacon leaves. The main constituents of the most active fraction were identified. Five organic extracts and pure crystalline enhydrin were administered to normoglycemic, transiently hyperglycemic and streptozotocin (STZ)-diabetic rats. The fasting and post-prandial blood glucose, and serum insulin levels were estimated and an oral glucose tolerance test (OGTT) was performed for the evaluation of hypoglycemic activity and dose optimization of each extract.We found that the methanol, butanol and chloroform extracts showed effective hypoglycemic activity at minimum doses of 50, 10 and 20 mg/kg body weight, respectively, and were selected for further experiments. Oral administration of a single-dose of each extract produced a slight lowering effect in the fasting blood glucose level of normal healthy rats, whereas each extract tempered significantly the hyperglycemic peak after food ingestion. Daily administration of each extract for 8 weeks produced an effective glycemic control in diabetic animals with an increase in the plasma insulin level. Phytochemical analysis of the most active fraction, the butanol extract, showed that caffeic, chlorogenic and three dicaffeoilquinic acids were significant components. Additionally, enhydrin, the major sesquiterpene lactone of yacon leaves, was also effective to reduce post-prandial glucose and useful in the treatment of diabetic animals (minimum dose: 0.8 mg/kg body weight).The results presented here strongly support the notion that the phenolic compounds above as well as enhydrin are important hypoglycemic principles of yacon leaves that could ameliorate the diabetic state.     

Antihyperglycemic and antioxidative attribute of hydroethanolic extract of Butea monosperma (Lam.) seeds and its active constituents

Treatment of diabetic mice with glibenclamide and crude extract (BE) significantly declined the FBG content. However, amongst the 6 isolated compounds, 3 compounds (C1, C4 and C6) appreciably subsided the exaggerated level of FBG. Simultaneously, glibenclamide, BE, C4 and C6 treatment markedly enhanced the hepatic glycogen content as compared to diabetic control group. Administration of crude extract, C4, C5 and C6 also exerted a protective effect on the declined activity of SOD, CAT and GSH-Px in the three tissues. However, all the herbal treatments produced a pronounced escalation in GSH content. Contrarily the elevated level of hepatic, pancreatic and renal TBARS monitored in diabetic animals was significantly diminished in treated groups of animals. Alloxan administration severely deteriorated the structure of liver and pancreas of diabetic mice, which was found to be restored to a certain extent in glibenclamide, BE and C6 treated animals. Identification of the most potent antihyperglycemic compound C6 by HPLC confirmed its triterpene nature. C6 was then further characterized via various spectroscopic methods (IR, NMR and Mass) that revealed its similarity with laccijalaric ester-I, a triterpene present in soft resin of B. monosperma seeds.     

龙眼核提取液的降血糖作用

以常规降血糖药(格列苯脲)为阳性对照,通过对正常小鼠和糖尿病小鼠进行降血糖治疗试验,研究了龙眼核提取液的降血糖作用。结果表明,龙眼核提取液能有效地缓解经四氧嘧啶诱发的糖尿病小鼠体内的高血糖症状,降血糖率达77.4%,具有良好的降血糖效果。     

Hypoglycemic effects of the wood of Taxus yunnanensis on streptozotocin-induced diabetic rats and its active components

Hypoglycemic effects of the H(2)O and MeOH extracts of the wood of Taxus yunnanensis were examined in streptozotocin (STZ)-induced diabetic rats. The H(2)O extract significantly lowered the fasting blood glucose level by 33.7% at a 100mg/kg dose on intraperitoneal administration. From the active H(2)O extract of the wood, three lignans, i.e., isotaxiresinol (1), secoisolariciresinol (2) and taxiresinol (3), were isolated as major components. These lignans were further tested for their hypoglycemic effects on the same experimental model. At a dose of 100mg/kg (i.p.), isotaxiresinol (1) reduced the fasting blood glucose level of diabetic rats by 34.5%, while secoisolariciresinol (2) and taxiresinol (3) reduced by 33.4% and 20.9%, respectively. The blood glucose lowering effects of 1 and 2 were stronger than the mixture of tolbutamide (200mg/kg) and buformin (1mg/kg) used as a positive control, which lowered fasting blood glucose level by 24.0%.     

Cooperative Anti-Diabetic Effects of Deoxynojirimycin-Polysaccharide by Inhibiting Glucose Absorption and Modulating Glucose Metabolism in Streptozotocin-Induced Diabetic Mice

We had previously shown that deoxynojirimycin-polysaccharide mixture (DPM) not only decreased blood glucose but also reversed the damage to pancreatic β-cells in diabetic mice, and that the anti-hyperglycemic efficacy of this combination was better than that of 1-deoxynojirimycin (DNJ) or polysachharide alone. However, the mechanisms behind these effects were not fully understood. The present study aimed to evaluate the therapeutic effects of DPM on streptozotocin (STZ)-induced diabetic symptoms and their potential mechanisms. Diabetic mice were treated with DPM (150 mg/kg body weight) for 90 days and continued to be fed without DPM for an additional 30 days. Strikingly, decrease of blood glucose levels was observed in all DPM treated diabetic mice, which persisted 30 days after cessation of DPM administration. Significant decrease of glycosylated hemoglobin and hepatic pyruvate concentrations, along with marked increase of serum insulin and hepatic glycogen levels were detected in DPM treated diabetic mice. Results of a labeled ¹³C₆-glucose uptake assay indicated that DPM can restrain glucose absorption. Additionally, DPM down-regulated the mRNA and protein expression of jejunal Na⁺/glucose cotransporter, Na⁺/K⁺-ATPase and glucose transporter 2, and enhanced the activities as well as mRNA and protein levels of hepatic glycolysis enzymes (glucokinase, phosphofructokinase, private kinase and pyruvate decarboxylas E1). Activity and expression of hepatic gluconeogenesis enzymes (phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) were also found to be attenuated in diabetic mice treated with DPM. Purified enzyme activity assays verified that the increased activities of glucose glycolysis enzymes resulted not from their direct activation, but from the relative increase in protein expression. Importantly, our histopathological observations support the results of our biochemical analyses and validate the protective effects of DPM on STZ-induced damage to the pancreas. Thus, DPM has significant potential as a therapeutic agent against diabetes.     

Long-Lasting Expression of HO-1 Delays Progression of Type I Diabetes in NOD Mice

Heme oxygenase-1 (HO-1) is crucial in regulating oxidative injury. The present study was designed to assess whether HO-1 upregulation by cobalt protoporphyrin IX (CoPP) moderates or prevents the diabetic state in non-obese diabetic (NOD) mice, an animal model for Type 1 diabetes (T1D). HO-1 expression and HO activity were upregulated in the pancreas by the intermittent administration of CoPP. This was associated with decreases in blood glucose and pancreatic O2-, but increased pAKT and BcL-XL and cell survival. A considerable number of beta cells were preserved in the islets of CoPP-treated NOD mice, while none were found in untreated diabetic mice. The number of CD11c+ dendritic cells was decreased in the pancreas of CoPP-treated NOD mice (p