Effect of Tartary Buckwheat Boiled Noodles on Postprandial Blood Glucose Level and Its Active Components / 日本補完代替医療学会誌

Dry solid matter (rutin content: 51.6 mg/g; quercetin content: 72.2 mg/g) extracted from Tartary buckwheat boiled noodles using 70% methanol as the solvent was found to have α-glucosidase inhibitory activity. As for fractions fractionated by silica gel column chromatography, the fractions rich in quercetin and rutin showed remarkable α-glucosidase inhibitory activity. Tartary buckwheat boiled noodles used as samples in this study contained quercetin produced from rutin by the action of rutinase, suggesting that both rutin and quercetin contained were involved in the α-glucosidase inhibitory activity of the dry solid extract. Changes in postprandial blood glucose levels were compared for boiled noodles made from two types of buckwheat (i.e., Tartary buckwheat and common buckwheat), revealing that blood glucose elevation after eating Tartary buckwheat boiled noodles was suppressed. The blood glucose level 40 minutes after eating Tartary buckwheat boiled noodles was significantly low (p<0.05). It can be concluded that this might be caused by the α-glucosidase inhibitory activity of rutin (270.0 mg) and quercetin (330.5 mg), which correspond to a total amount of 935 mg of rutin equivalents, in the gastrointestinal tract. As a result, the digestion of carbohydrates contained in the samples consumed and their absorption by the intestine might be inhibited, resulting in the suppression of increases in blood glucose levels. The presence of a certain amount of quercetin was considered to be key to the suppression of blood glucose elevation. It is important to control rapid postprandial blood glucose increases to prevent diabetes from developing or becoming serious. This study suggests the potential for Tartary buckwheat boiled noodles to contribute to diabetes prevention.

New phenolic constituents obtained from Polygonum multiflorum / 中草药·英文版

Objective: To isolate the phenolic compounds obtained from the dried roots of Polygonum multiflorum and investigate their pharmacological activities. Methods: The chemical constituents were isolated and purified by combining them with a macroporous resin (DM-8), MCI gel, and Sephadex LH-20 and by performing ODS column chromatography. Their structures were elucidated by 1D and 2D NMR analyses, as well as mass spectrometry. The isolated compounds were evaluated to determine their hepatoprotective and α-glucosidase inhibitory activities in vitro. Results: Two phenolic compounds, namely, polygonimitin E (1) and polygonimitin F (2), were isolated from the dried roots of P. multiflorum. Compound 2 (10 µmol/L) only showed moderate hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage. Unfortunately, these two compounds exhibited no α-glucosidase inhibitory activity. Conclusion: Compounds 1 and 2 were new compounds. Compound 2 could be one of the potential hepatoprotective constituents of P. multiflorum.

Antidiabetic effect of Chrysophyllum albidum is mediated by enzyme inhibition and enhancement of glucose uptake via 3T3-L1 adipocytes and C2C12 myotubes

Objective: To investigate the in vivo and in vitro antidiabetic potential of Chrysophyllum albidum. Methods: The effects of oral treatment with hydro-ethanolic extract (125, 250 and 500 mg/kg) of the stem bark of Chrysophyllum albidum and glibenclamide for 21 d on glucose level, serum enzyme markers for liver function, lipid profile, total protein, serum urea, serum creatinine, and body weight were evaluated in experimental diabetic rats administered with 45 mg/kg of streptozotocin. In vitro assays including glucose uptake in C2C12 cells and 3T3-L1 adipose tissues, α-glucosidase and α-amylase inhibition were employed to evaluate the possible mechanism of hypoglycemic action of the extract. DPPH and nitric oxide radical antioxidant activity of the extract was also measured. Results: The increased levels of blood glucose, triglycerides, low-density lipoprotein, total cholesterol, serum aspartate, and alanine transaminases, creatinine, and urea in the diabetic animals were reduced significantly (P<0.01) after treatment with Chrysophyllum albidum extract. The decreased total protein and high-density lipoprotein concentrations were normalized after treatment. In addition, the extract significantly (P<0.01) increased the transport of glucose in 3T3-L1 cells and C2C12 myotubes and exhibited considerable potential to inhibit α-amylase and α-glucosidase. It also demonstrated potent antioxidant action by scavenging considerably DPPH and nitric oxide radicals. Conclusions: Chrysophyllum albidum stem bark extract exhibits considerable antidiabetic effect by stimulating glucose uptake and utilization in C2C12 myotubes and 3T3-L1 adipocytes as well as inhibiting the activities of α-amylase and α-glucosidase.

New octadecanoid derivatives from the seeds of Ipomoea nil / 中国天然药物

Four new octadecanoid derivatives (1-4) including a pair of enantiomers (1/2), along with 12 known analogues (5-16), were isolatedfrom the seeds of Ipomoea nil. Their structures were determined by detailed spectroscopic analyses and comparison with reported data of structurally related compounds, with the absolute configurations of 1 and 2 being assigned by an in situ dimolybdenum ECD method. Our bioassays revealed that these isolates did not show ABTS radical scavenging activity while 10 and 13 displayed better α-glucosidase inhibitory activity than the positive control acarbose (IC 167.7 ± 1.55 μmol·L), with IC of 92.73 ± 3.12 and 11.39 ± 2.18μmol·L, respectively.

In vitro α-glucosidase inhibition and antioxidant activities of partially purified Antidesma bunius fruit and Gynura nepalensis leaf extracts.

Diabetes mellitus is a metabolic disorder characterized by increased blood glucose levels. Current treatments involve the use of sulfonylureas, α-glucosidase inhibitors, and other synthetic drugs. The study demonstrated the α-glucosidase inhibition and antioxidant properties of partially purified ethanolic extracts of Antidesma bunius fruits and Gynura nepalensis leaves, as possible herbal drug candidates. After ethanol extraction, the extracts were fractionated using normal phase liquid column chromatography, with elution solvents ethyl acetate, methanol and water. Fractionation resulted in five fractions for A. bunius (A1, A2, A3, A4 and A5) and seven fractions for G. nepalensis (G1, G2, G3, G4, G5, G6 and G7). Fraction G1 showed the highest α-glucosidase inhibition activity (90.61±8.05%) and possibly acted via a mixed mode of inhibition. For the antioxidant activities, Fraction A1 exhibited highest radical scavenging activity via DPPH assay (97.39±2.48%), Fraction G7 exhibited highest iron (II)-chelating activity (95.85±1.46%) and Fraction G6 exhibited highest ferric-ion reducing activity via FRAP assay (272.60 μg/mL FeSO4 equivalents). Phytochemical screening revealed that flavonoids and tannins were common among all fractions. The results demonstrated the potential of these plants as an antidiabetic herbal treatment. However, further studies needs to be done, specifically focusing on isolating the active component(s), structure and mechanism elucidation and toxicity assays.

Synthesis, Characterization and α- Glucosidase Inhibition of Some Copper, Cobalt, Nickel and Zinc Complexes with N – Methylethylenediamine.

Aims: The aim of current study to examine percentage inhibition of α-glucosidase by synthesized metal complexes. Study Design: The α-glucosidase inhibitory activity assay was performed by Tripathi et al. method with minor modification Place and Duration of Study: Faculty of Science and Environment and Department of Physical Sciences, between June 2009 and July 2010. Methodology: In the present work we have synthesized metal [Cu(II), Co(II), Ni(II), Zn(II)] complexes with N - methylethylenediamine. We synthesized total twelve metal complexes by various salts i.e. nitrate, sulphate and chloride of copper, cobalt, nickel and zinc. Synthesized metal complexes characterized via IR spectroscopy and cyclovoltametry. We examined percentage inhibition of α-glucosidase by synthesized metal complexes. IC50 value of metal complexes was also calculated. Results: All twelve complexes possess α-glucosidase inhibition activity, among them [Co (men)3]2NO3 have the highest α-glucosidase inhibition, having IC50 value 900 µg/ml and [Ni (men)3]2Cl have the lowest α-glucosidase inhibition, having IC50 value 2533.21 µg/ml. Conclusion: Diabetes is a proven and inherited type of disorder transition metal ions are essential nutrients to all forms of life. Iron, copper, zinc, manganese, cobalt and nickel all have unique chemical and physical properties that make them useful metals for biological systems so this type of approach may be useful. We have done in-vitro study; however, need further work to validate reliability.

Simultaneous quantification of ten constituents of Xanthoceras sorbifolia Bunge using UHPLC-MS methods and evaluation of their radical scavenging, DNA scission protective, and α-glucosidase inhibitory activities / 中国天然药物

The present study was designed to investigate the bioactive constituents of Xanthoceras sorbifolia in terms of amounts and their antioxidant, DNA scission protection, and α-glucosidase inhibitory activities. Simultaneous quantification of 10 X. sorbifolia constituents was carried out by a newly established ultra-high performance liquid chromatography-quadrupole mass spectrometry method (UHPLC-MS). The antioxidant activities were evaluated by measuring DPPH radical scavenging and DNA scission protective activities. The α-glucosidase inhibitory activities were investigated by using an assay with α-glucosidase from Bacillus Stearothermophilus and disaccharidases from mouse intestine. We found that the wood of X. sorbifolia was rich in phenolic compounds with the contents of catechin, epicatechin, myricetin, and dihydromyricetin being 0.12-0.19, 1.94-2.16, 0.77-0.91, and 6.76-7.89 mg·g(-1), respectively. The four constituents strongly scavenged DPPH radicals (with EC50 being 4.2, 3.8 and 5.7 μg·mL(-1), respectively) and remarkably protected peroxyl radical-induced DNA strand scission (92.10%, 94.66%, 75.44% and 89.95% of protection, respectively, at a concentration of 10 μmol·L(-1)). A dimeric flavan 3-ol, epigallocatechin-(4β→8, 2β→O-7)-epicatechin potently inhibited α-glucosidase with an IC50 value being as low as 1.2 μg·mL(-1). The established UHPLC-MS method could serve as a quality control tool for X. sorbifolia. In conclusion, the high contents of antioxidant and α-glucosidase inhibitory constituents in X. sorbifolia support its use as complementation of other therapeutic agents for metabolic disorders, such as diabetes and hypertension.

Antioxidant Potential and Type II Diabetes Related Enzyme Inhibition Properties of Raw and Processed Legumes in Indian Himalayas.

In vitro antioxidant potential and type II diabetes related enzyme inhibition capacity was analyzed in methanolic extract of raw and processed seeds of seven prominent legume genotypes, originated in Indian Himalayas. In raw seeds, total free phenolic content ranged from 2.18 ± 1.9 (small-seeded urd bean) to 13.11 ± 2.4 (bold-seeded grass pea) mg gallic acid/g extract dry weight basis (dwb), while total flavonoids varied between 1.89 ± 0.61(lima bean) and 0.41 ± 0.9 (small-seeded urd bean) mg catechin/ g of the extracts, dwb. Raw seed extracts exhibited scavenging capacity against DPPH (30.80 - 66.40 %), superoxides (43.78- 71.22%) and hydrogen peroxide (11.19-53.78%) along with ferric reducing/antioxidant power (FRAP, 37.87-161.32 μmol/g extract dwb) and inhibition of ß-carotene degradation (23.45-49.11%). In type II diabetes related enzyme inhibition activity, the value varied from 8.11% (urd bean) to 21.34% (lima bean) for α-amylase and from 27.12% (urd bean) to 87.54% (grass pea) for α-glucosidase in raw seed extracts under in vitro bioassay. Among the processing methods, sprouting followed by direct cooking showed significant enhancement of antioxidant activity along with balanced levels of enzyme inhibition capacity, while soaking + cooking as well as roasting showed diminishing effects. Oil-frying exhibited mixed effects. Bold-seeded lima bean, grass pea and black-seeded common beans were superior to lentil, small-seeded urd bean and white-seeded beans. Phenolic content was correlated with antioxidant properties and enzyme inhibition activity, but this association was stronger in sprouting and direct cooking than raw seeds and other three methods.

In vitro antioxidant potential and type II diabetes related enzyme inhibition properties of traditionally processed legume-based food and medicinal recipes in Indian Himalayas.

In vitro antioxidant potential of methanolic extracts of six legume-based traditional plant recipes used in Indian Himalayas were evaluated by trolox equivalent antioxidant capacity (TEAC), scavenging of 1,1-diphenyl-2- picrylhydrazyl (DPPH), superoxide radical, hydrogen peroxide, ferric reducing antioxidant power (FRAP) and inhibition of ß-carotene degradation activity (IBDA). Type II diabetes-related enzyme inhibition capacity of recipes was assayed on α-amylase and α-glucosidase activity under in vitro assay. The methanolic extracts of six recipes showed substantially high total phenolic and flavonoid content along with TEAC, radical scavenging activities, FRAP and IBDA in significantly different magnitudes. Apart from high magnitude of antioxidant potential, the three recipes namely ‘methi paste’, ‘arhar dal’ and ‘ghew simi’ used during diabetes by local people exhibited moderate to high level of enzyme inhibition capacity. Present results suggest that methanolic extracts of six indigenous recipes are rich in polyphenols and antioxidant activity. The three medicinal preparations have high potential to inhibit type II diabetes-related enzyme activity, and may be integrated into dietary management of type II diabetes.