Indigofera arrecta prevents the development of hyperglycaemia in the db/db mouse

Genetically obese diabetic and nondiabetic mice, and their lean littermates were used to evaluate an aqueous extract of Indigofera arrecta which is used for the treatment of diabetes. Control animals were given water instead of the extract over a 90 day period, and measurements of blood glucose and body weight were done at approximately 30-day intervals. The development of hyperglycaemia associated with the diabetic mice over a time period was absent when the mice were on the extract. Blood glucose levels of littermates of both mutant strains, and the mild hyperglycaemia of the obese nondiabetic mice were not affected. The extract significantly lowered the body weight of both types of obese mutant mice but did not affect the body weight of the littermates.     

Indigofera arrecta: safety evaluation of an antidiabetic plant extract in non-diabetic human volunteers

In order to exclude the effects of diabetes and its complications on the results, this paper examined the effects of I. arrecta extract in 12 healthy young male adult non-diabetic Ghanaians. Volunteers were given a physical examination before and after the administration of plant extract. Similarly blood pressure (systolic and diastolic, in mmHg) were also taken before and after administration of the extract. Effects of the extract on fasting blood glucose, haematological indices, and liver and kidney functions were investigated. Fasting blood specimens were collected from each subject before, during and after the study. Levels of marker enzymes and metabolites for liver and kidney status, and haematological indices were measured. Urine volume and creatinine content were also measured. I. arrecta extract did not alter the mean systolic and diastolic pressures. Fasting blood glucose also did not change. Serum marker enzymes and metabolites for hepatic and renal functions remained normal. However, Indigofera arrecta extract increased the erythrocyte sedimentation rate (ESR) and decreased lymphocyte concentration in the blood. The data suggest that I. arrecta may not have overt toxic reactions but could affect the immune status of users. © 1998 John Wiley & Sons, Ltd.     

Diabetic patients' response to oral administration of aqueous extract of Indigofera arrecta

Clinical laboratory data on six male diabetic patients attending an out-patient clinic at the Centre for Scientific Research into Plant Medicine (CSRPM) were used to evaluate the therapeutic and possible toxic effects of Indigofera arrecta, a plant used at CSRPM for the control of diabetes mellitus. Levels of plasma glucose and serum triacylglycerol (TG) were used as indices for therapeutic effect; serum proteins, bilirubin, cholesterol and the enzymes gamma glutamyl transferase, alkaline phosphatase, and the aminotransferases for hepatotoxic effects; and blood urea nitrogen, serum creatinine and its clearance rate as indices of nephrotoxicity. Hematological indices were also measured. The results show that an aqueous extract of I. arrecta administered orally, significantly lowered blood glucose levels during the first 2 weeks of administration. Levels of serum TG and aspartate aminotransferase were significantly lowered at the end of the 12 week treatment period. There was also a significant decrease in blood creatinine levels accompanied by an increase in creatinine clearance rate. Other metabolites, enzymes, excretory products and hematological indices that were determined were not affected. The results indicate that the mode of action of the plant extract is not primarily through lowering of blood glucose.     

花木蓝根中新的3-硝基丙酰基吡喃葡萄糖

目的研究花木蓝Indigofera kirilowii根的化学成分。方法采用液-液萃取、硅胶柱色谱、重结晶等方法分离纯化，根据核磁共振谱、质谱等鉴定化合物的结构。结果从花木蓝根的乙醇提取物中分离鉴定了以下化合物：3，4-二-O-（3-硝基丙酰基）-D-吡喃葡萄糖α-和β-端基异构体约3：1的混合物（Ⅰ和Ⅱ）、ononin（7-hydroxy-4’-methoxyisoflavone-7-O-β-D-glucopyranoside，Ⅲ）和6-O-（3-硝基丙酰基）-D-吡喃葡萄糖α-和β-端基异构体约1：1的混合物（Ⅳ和Ⅴ）。结论化合物Ⅰ和Ⅱ为新化合物，化合物Ⅲ为首次从木蓝属植物中分离得到，化合物Ⅳ和Ⅴ为首次从花木蓝中分离得到。     

Experimental antihyperglycemic effect of diterpenoids of llareta Azorella compacta (Umbelliferae) Phil in rats

Aqueous or ethanol infusions of Azorella compacta (llareta) in common with many other plants have been used as antidiabetic in the popular medicine in the altiplanic region of Chile. In order to determine if the diterpenic compounds chemically elucidated and isolated from this plant are responsible for this effect, streptozotocin diabetic rats (507 +/- 67 mg/mL glucose) were injected with two injections of diterpenic compounds mulinolic acid, azorellanol, and mulin-11,13-dien-20-oic acid at 180 mg/mL. Glycemia of animals treated with mulinolic acid and azorellanol was decreased to 243 +/- 2 and 247 +/- 14 mg/mL respectively, values very close to those reached by chlorpropamide injection used in controls. After 3 h treatment with mulin-11,13-dien-20-oic acid no effect was detected. The blood serum insulin in diabetic rats (146 +/- 58 pg/mL) was lower than in control rats. After injection of azorellanol, insulin was elevated to 247 +/- 23 pg/mL but with mulinolic acid, insulin was not changed. The antihyperglycemic effect of these compounds may explain the effectiveness of llareta in popular medicine. Because of the similarity to the hypoglycemic medication chlorpropamide, azorellanol could be acting on the beta cells of pancreatic islets, while mulinolic acid may act upon glucose utilization or production in the liver.     

Evaluation of the antithyroid, antioxidative and antihyperglycemic activity of scopoletin from Aegle marmelos leaves in hyperthyroid rats

Scopoletin (7-hydroxy-6-methoxy coumarin) was isolated from the leaves of Aegle marmelos and evaluated for its potential to regulate hyperthyroidism, lipid peroxidation and hyperglycemia in levo-thyroxine-induced hyperthyroid rats. Scopoletin (1.00 mg/kg, p.o.) administered daily for 7 days to levo-thyroxine-treated animals decreased the levels of serum thyroid hormones and glucose as well as hepatic glucose-6-phosphatase activity, demonstrating its potential to regulate hyperthyroidism and hyperglycemia. Scopoletin also inhibited hepatic lipid peroxidation and increased the activity of antioxidants, superoxide dismutase and catalase. Compared with the standard antithyroid drug, propylthiouracil, scopoletin exhibited a superior therapeutic activity, since unlike propylthiouracil, it also inhibited hepatic lipid peroxidation. These findings indicate that scopoletin has the potential to inhibit thyroid function and hyperglycemia without hepatotoxicity.     

Investigation in rats of the antihyperglycemic effect of plant extracts used in taiwan for the treatment of diabetes mellitus

In order to clarify the hypoglycemic activity of plants that are widely used to treat diabetes mellitus in Taiwan, the present study investigated the effectiveness of ten plant extracts by screening the decrease of blood glucose level in streptozocin-induced diabetic rats. We found that only six plant extracts exhibited blood glucose lowering activities in the rat. Blood levels of insulin were also determined using radioimmunoassay methods. Lack of an increase of insulin-like immunoreactivity in rats treated with these six plant extracts ruled out the mediation of insulin-dependent mechanisms. Similar effects were also observed in glucose-challenged rats treated with these extracts. The results confirmed the hypoglycemic activity of these plants and suggested that this action was produced through an insulin-independent mechanism.     

Hypoglycemic and Antihyperglycemic Activities of Nine Medicinal Herbs Used as Antidiabetic in the Region of Lubumbashi (DR Congo)

The aim of this study was to assess the hypoglycemic and antihyperglycemic activities of nine plants used as antidiabetic treatments in Lubumbashi and its surroundings. Those are Albizia adianthifolia, Azanza garckeana, Cassia occidentalis, Cassia sieberiana, Erythrina abyssinica, Gladiolus klattianus, Rauvolfia caffra, Strychnos spinosa, and Vitex madiensis. Aqueous extracts, obtained by decoction and maceration, were administered (500 mg/kg) per os to guinea pigs (Cavia porcellus), both in glucose baseline conditions and in oral glucose tolerance test (OGTT) conditions (glucose, 2 g/kg; follow‐up over 210 min). For OGTT experiments, area under the curve of blood glucose levels, maximum glucose concentration (Cmax), and time to reach Cmax (Tmax) were used to compare test groups with the control conditions (glucose group). In hypoglycemic tests, only three species induced significant (p < 0.001) lowering of normal glycemia: A. adianthifolia (33% reduction), C. occidentalis (32%), and V. madiensis (43%); in the same conditions, the positive control glibenclamide (6 mg/kg) induced a blood glucose lowering of 55%. In OGTT conditions, all tested herbs were active, with the highest inhibition of glycemia increases for V. madiensis (62%) and A. adianthifolia (57%), compared with the hyperglycemic inhibition rate of glibenclamide (50%). Oral glucose tolerance test conditions appear as essential to detect the extracts most interesting for clinical use. These data support the use of studied plants for diabetes treatment in traditional Congolese medicine and indicate a good knowledge of tradipraticians in the field. Copyright © 2017 John Wiley & Sons, Ltd.     

The effect of medicinal plants of Islamabad and Murree region of Pakistan on insulin secretion from INS-1 cells

In vitro testing of the extracts of medicinal plants collected from Islamabad and the Murree region on insulin secretagogue activity was carried out. Dried ethanol extracts of all plants (ZH1-ZH19) were dissolved in ethanol and DMSO, and tested at various concentrations (between 1 and 40 microg/mL) for insulin release from INS-1 cells in the presence of 5.5 mM glucose. Glibenclamide was used as a control. Promising insulin secretagogue activity in various plant extracts at 1, 10, 20 and 40 microg/mL was found, while in some cases a decrease in insulin secretion was also observed. Artemisia roxburghiana, Salvia coccinia and Monstera deliciosa showed insulin secretagogue activity at 1 microg/mL (p < 0.05) while Abies pindrow, Centaurea iberica and Euphorbia helioscopia were active at 10 microg/mL (p < 0.05). Extracts of Bauhinia variegata and Bergenia himalacia showed effects at 20 microg/mL (p < 0.05), and Taraxacum officinale and Viburnum foetens at 40 microg/mL (p < 0.05). Insulin secretagogue activity could not be detected in the extracts of Adhatoda vasica, Cassia fistula, Chrysanthemum leucanthemum, Morus alba, Plectranthus rugosus, Peganum harmala and Olea ferruginea. The results suggest that medicinal plants of Islamabad and the Murree region of Pakistan may be potential natural resources for antidiabetic compounds.     

Insulinotropic activity of Tinospora crispa extract: effect on ß-cell Ca2+ handling

The mechanism of insulinotropic action of Tinospora crispa was investigated in vitro using an insulin-secreting clonal ß-cell line, HIT-T15. The aqueous extract sensitizes the ß-cell to extracellular Ca²⁺ and promotes intracellular Ca²⁺ accumulation which in turn causes increased insulin release. The increase in cytosolic Ca²⁺ concentration is due to stimulation of Ca²⁺ uptake from the extracellular medium and inhibition of Ca²⁺ efflux from the cytosol. That the mechanism of insulinotropic action of T. crispa is physiological suggests that the insulin secretagogue/s present in the extract could indeed be a potential source of a specific oral hypoglycaemic agent for the treatment of non-insulin-dependent diabetes mellitus. © 1998 John Wiley & Sons, Ltd.     

Isolation, structure elucidation and in vivo hepatoprotective potential of trans-tetracos-15-enoic acid from Indigofera tinctoria Linn

The bioassay guided fractionation of the dried aerial part of Indigofera tinctoria Linn. led to the identification of an active fraction labelled as indigotin. On further chemical analysis, a compound isolated from indigotin was identified and characterized as trans-tetracos-15-enoic acid (TCA). The chemical structure of this compound was established on the basis of physical properties and spectral data, including NMR. It afforded significant hepatoprotection against carbon tetrachloride and paracetamol induced hepatotoxicity in experimental models. Silymarin, a well known plant based hepatoprotective agent, and N-acetylcysteine, which has proven efficacy as a replenisher of sulfhydryls, were used for relative efficacy. TCA was found to reverse the altered hepatic parameters in experimental liver damage. In the safety evaluation study the oral LD50 was found to be more than 2000 mg/kg, with no signs of abnormalities or any mortality for the 15 day period of observation after administration of a single dose of drug in mice. The studies revealed significant and concentration dependent hepatoprotective potential of TCA as it reversed the majority of the altered hepatic parameters in experimental liver damage in rats and mice and may be useful in the management of liver disorders.     

黄精多糖对链脲菌素糖尿病大鼠降血糖作用及其机制探讨

目的:探讨黄精多糖(PSP)对链脲菌素(STZ)诱导的糖尿病大鼠的降血糖作用及其可能机制.方法:采用STZ(60 mg·kg~(-1))腹腔注射法建立糖尿病大鼠模型.造模第30 d测定大鼠体重、进食量、进水量和尿量;末次给药24 h后,腹主动脉取血,分离血清.采用葡萄糖氧化酶法测定大鼠空腹血糖(FBG)、放射免疫方法检测血清胰岛素(INS)、化学比色法测定糖化血清蛋白(GSP);采用胰腺组织切片HE染色和免疫组化染色法对胰岛结构和胰岛素表达情况进行观察;原位末端标记法(TUNEL)标记STZ糖尿病大鼠胰岛凋亡细胞;采用免疫组化染色观察各组大鼠胰岛细胞caspase-3蛋白表达.结果:模型组大鼠呈现多饮多尿多食、体重下降、血糖升高和胰岛结构破坏.PSP(390,780 mg·kg~(-1))组大鼠的进食量、进水量和尿量指标显著低于模型组,同时FBG和GSP降低,血清INS含量上升,胰岛形态改善,INS表达增强.模型组细胞凋亡率和caspase-3表达显著升高(P<0.01);PSP各剂量组胰岛细胞凋亡率和caspase-3表达显著下降.结论:PSP能够降低STZ糖尿病大鼠血糖,提高胰岛素表达,其机制可能与其抑制胰岛细胞凋亡,下调caspase-3表达有关.     

糖肝康对糖尿病脂肪肝大鼠肝组织cAMP反应元件结合蛋白表达的影响

目的观察糖肝康对糖尿病脂肪肝大鼠肝组织cAMP反应元件结合蛋白(CREB)表达的影响,探讨其作用机制。方法采用链脲佐菌素联合高脂饮食复制糖尿病脂肪肝大鼠模型。造模成功后随机分为模型组、护肝宁组和糖肝康小、中、大剂量组,每组10只,另取10只正常大鼠作为空白组。各给药组给予相应药物干预,12周后采用Western blot检测大鼠肝组织CREB的表达。结果与空白组比较,模型组肝组织CREB表达明显增高(P0.01);与模型组比较,各给药组肝组织CREB表达明显减少(P0.01),糖肝康中、大剂量组优于护肝宁组(P0.01)。结论糖肝康可能通过降低CREB表达水平改善肝脏代谢,进而保护肝脏。     

滋养肝肾、活血化瘀中药对实验性糖尿病大鼠视神经组织形态的影响

目的：观察滋养肝肾、活血化瘀复方制剂对实验性糖尿病大鼠视神经组织形态的影响。方法：用四氧嘧啶造成Ｗｉｓｔａｒ大鼠糖尿病模型，于造模后７天开始给中药复方制剂灌胃６个月，以达美康作对照。光镜下观察比较大鼠视神经组织结构。结果：中药治疗组的糖尿病大鼠视神经纤维退变和神经髓鞘脱失的程度均显著低于阴性对照组和阳性对照组（Ｐ＜０．０１，０．００１）。结论：滋养肝肾、活血化瘀中药有减轻实验性糖尿病大鼠视神经病理损害的作用。     

丹蛭降糖胶囊对糖尿病模型大鼠趋化因子9和白细胞介素-8的影响

目的：观察丹蛭降糖胶囊对糖尿病大鼠趋化因子9（CXCL9）和白细胞介素-8（IL-8）表达的影响,探讨其干预2型糖尿病的作用机制。方法取55只雄性SD大鼠,随机分为正常组、丹蛭高剂量组、丹蛭低剂量组、吡格列酮组、模型组。正常组予基础饲料喂养,其余各组给予高脂饲料喂养,采用链脲佐菌素单次腹腔注射35 mg/kg,建立糖尿病动物模型,120 h后测血糖。造模成功后,丹蛭高、低剂量组分别予丹蛭降糖胶囊1.08、0.54 g/（kg？d）灌胃,吡格列酮组予吡格列酮10 mg/（kg？d）灌胃,正常组和模型组给予生理盐水5 mL/（kg？d）灌胃,连续8周。双抗体夹心法测定大鼠血清中CXCL9和IL-8含量及血糖、血脂。结果与正常组比较,模型组CXCL9和IL-8的表达明显升高（P＜0.05,P＜0.01）;与模型组比较,丹蛭高、低剂量组CXCL9、IL-8的高表达及血糖、血脂明显降低（P＜0.01）。结论丹蛭降糖胶囊具有抑制糖尿病炎症因子高表达,达到降低血糖、调节血脂的作用。     

Pharmacological basis for the gut stimulatory activity of Raphanus sativus leaves

The crude extract of Raphanus sativus leaves (Rl.Cr) showed a dose-dependent (0.03-5.0 mg/ml) spasmogenicity in guinea-pig ileum and colon. The effect was insensitive to atropine pre-treatment but was completely abolished by pyrilamine indicating involvement of histaminergic (H(1)) receptors. The contractile effect at high doses (3.0-5.0mg/ml) was followed by relaxation. Rl.Cr also enhanced the transit of charcoal meal in mice at 30-100 mg/kg. The petroleum spirit, chloroform and aqueous fractions all showed histaminergic activity in ileum; aqueous fraction being more potent. The study shows the presence of a histaminergic component(s) along with a weak spasmolytic factor thus providing sound mechanistic basis for the traditional use of the plant in constipation.     

Evaluation of khat (Catha edulis Forssk) for antifertility activity in rats

The effect of the methanolic extract of khat (Catha edulis Forssk) was studied on female fertility in rats. The parameters included the effect on oestrus cycle, implantation, foetal loss, abortion, inhibition of uterotrophic activity and teratogenicity. The extract, in the doses of 250 and 500 mg/kg, produced dose dependent and significant anti-implantation activity. However, it failed to produce complete infertility in this dose range. Treatment of animals during day 8 to day 12 of pregnancy produced significant abortifacient activity. There was significant decrease in the weight and length of foetuses delivered by rats treated with the extract but there were no gross abnormalities in the organs of the offsprings. It also produced significant anti-oestrogenic activity as assessed by the mean weight of the uteri of rats treated with oestradiol and its combination with the khat extract.     

Oral hypoglycemic effect of Salacia reticulata in the streptozotocin induced diabetic rat

The oral hypoglycemic activity of Salacia reticulata extract was evaluated in streptozotocin induced diabetic rats. The diabetic rats were orally administered an aqueous extract of Salacia reticulata and the plasma glucose concentration was determined at regular intervals following administration. The drug was effective as a hypoglycemic agent at all the doses tested (0.5 g/kg, 1.0 g/kg and 5.0 g/kg). The maximum percentage decrease in plasma glucose was observed between 1–5h following administration of the drug.     

Evaluation of hypoglycemic activity of total lignans from Fructus Arctii in the spontaneously diabetic Goto-Kakizaki rats

Ethnopharmacological relevance

Fructus Arctii, called “Niubangzi” in China (Great burdock achene in English), is a well-known Chinese Materia Medica. It is the dried ripe fruit of Arctium lappa L. (family Asteraceae) and was included in the Chinese pharmacopoeia for its traditional therapeutic actions. Meanwhile it has been utilized extensively in a number of classical drug formulas as a major component for the treatment of noninsulin-dependent diabetes mellitus. It has also been reported recently that the clinical use of Fructus Arctii resulted in a satisfactory hypoglycemic effect in diabetic patients. The aim of this study was to investigate hypoglycemic activity of total lignans from Fructus Arctii (TLFA) in Goto-Kakizaki (GK) rats, a spontaneous type 2 diabetic animal model, and the mechanism of its hypoglycemic activity.

Materials and methods

Male GK rats and normal Wistar rats were used in this study, GK rats fed twice daily were given TLFA (300 mg/kg) or nateglinide (50 mg/kg) orally before each meal for 12 weeks. Besides common evaluation indexes of hypoglycemic activity such as blood glucose level, oral glucose tolerance test (OGTT), glycated hemoglobin, as well as lipid metabolism parameters such as cholesterol (CHOL), triglycerides (TG), et al., in rat serum. The effects of TLFA on insulin secretion and pancreas tissue sections, the levels of serum glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and the α-glucosidase inhibitory activity of TLFA in vitro were investigated.

Results

TLFA demonstrated stable and long-lasting hypoglycemic activity in GK rats and showed significant improvement in glucose tolerance in glucose fed hyperglycemic GK rats. Both TLFA and nateglinide controlled the glycosylated hemoglobin levels of the experimental animals very well. Stimulation of insulin secretion was proved to be one of the hypoglycemic mechanism of TLFA, promoting the release of GLP-1 should be another one, and ɑ-glucosidase inhibitory activity of TLFA also contributes to its hypoglycemic activity. In this study, we didn't found that TLFA could effect the body weight of GK rats, which was also verified by the changes of biochemical parameters of blood in experimental rats.

Conclusion

The results of this study indicates that TLFA has significant hypoglycemic potential in GK rats, and it may be acting through stimulating insulin secretion, promoting the release of GLP-1, and decreasing intestinal absorption of glucose.