Decrease of Plasma Glucose by Allantoin, an Active Principle of Yam (Dioscorea spp.), in Streptozotocin-Induced Diabetic Rats

Chen

BMC Complement Altern Med

2014

Self Cite

BackgroundRhodiola rosea (Rhodiola) is a plant in the Crassulaceae family that grows in cold regions of the world. It is mainly used in clinics as an adaptogen. Recently, it has been mentioned that Rhodiola increases plasma β-endorphin to lower blood pressure. Thus, the present study aims to investigate the antidiabetic action of Rhodiola in relation to opioids in streptozotocin-induced diabetic rats (STZ-diabetic rats).MethodsIn the present study, the plasma glucose was analyzed with glucose oxidase method, and the determination of plasma β-endorphin was carried out using a commercially available enzyme-linked immunosorbent assay. The adrenalectomy of STZ-diabetic rats was used to evaluate the role of β-endorphin. In addition, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting analysis were performed to investigate mRNA and protein expressions.ResultsRhodiola-water extract dose-dependently lowered the plasma glucose in STZ-diabetic rats and this action was reversed by blockade of opioid μ-receptors using cyprodime. An increase of plasma β-endorphin by rhodiola-water extract was also observed in same manner. The plasma glucose lowering action of rhodiola-water extract was attenuated in bilateral adrenalectomized rats. In addition, continuous administration of rhodiola-water extract for 3 days in STZ-diabetic rats resulted in an increased expression of glucose transporter subtype 4 (GLUT 4) in skeletal muscle and a marked reduction of phosphoenolpyruvate carboxykinase (PEPCK) expression in liver. These effects were also reversed by blockade of opioid μ-receptors.ConclusionsTaken together, rhodiola-water extract improves hyperglycemia via an increase of β-endorphin secretion from adrenal gland to activate opioid μ-receptors in STZ-diabetic rats.

Section: Discussionsupporting

confidence: 84%

Antihyperglycemic action of rhodiola-aqeous extract in type1-like diabetic rats

Chen

BMC Complement Altern Med

2014

Self Cite

BMC Complement Altern Med

“…[10-13]. Modern research showed that yam extract has many physiological functions such as anti-diabetic, anti-hypercholesterolemia, anti-acetaminophen-induced hepatotoxicity and nephrotoxicity as well as antioxidant activity [12,14-17]. Interestingly, the water yam ( Dioscorea alata L.), another species Shan yao has been shown to possess antihypertensive activity in hypertensive animal models [18], suggesting that consumption of fresh yam tubers has potential health benefits for human beings.…”

Section: Introductionmentioning

confidence: 99%

Aqueous extract of dioscorea opposita thunb. normalizes the hypertension in 2K1C hypertensive rats

Amat

Abdureyim

et al. 2014

BackgroundDioscorea opposita Thunb. (Huai Shan Yao, DOT), a common staple food in China, has been used for more than 2000 years in traditional Chinese medicine (TCM) to treat different systemic diseases including hypertension. The objective of this study was to investigate the possible antihypertensive effects of the aqueous extract of (DOT) in renovascular hypertensive rats as well as the mechanism in reducing blood pressure.MethodsThe two-kidney one-clip (2K1C) Goldblatt model of renovascular hypertension was used in Wistar rats. Rats with captopril, low-dose DOT and high-dose DOT treated 2K1C groups for 6 weeks. The blood pressure, cardiac mass index (heart weight/body weight), plasma level of angiotensin-II (Ang-II), endothelin-1(ET-1), superoxide dismutase (SOD) and malondialdehyde (MDA) were evaluated.ResultsDOT significantly reduced mean systolic and diastolic blood pressure after treatment. DOT also significantly increased plasma SOD activity but decreased plasma MDA concentration. Renal function was improved with captopril and DOT. DOT reduced plasma Ang-II activity and plasma ET concentration. They couldalso significantly reduce the left ventricular hypertrophy and cardiac mass index.ConclusionsOur results suggest that DOT may have an antihypertensive effect on hypertension by inhibit ET-converting enzyme and antioxidant activity, which warrant further exploration.

Biological & Pharmaceutical Bulletin

“…15,16) Besides, the D. opposita rhizomes contain diverse chemicals such as allantoin and batatasin, known to have antioxidant, anti-inflammatory, and glucose lowering activities. 17,18) However, there has not been any attempt to reveal the anti-adipogenic effect of D. opposita. Our recent research suggested that n-BuOH fraction of D. opposita (DOB) and its phenolic constituents possess inhibitory activities against pancreatic lipase in vitro.…”

mentioning

confidence: 97%

Anti-adipogenic Constituents from <i>Dioscorea opposita</i> in 3T3-L1 Cells

Yang

Chin

Chae

et al. 2014

We previously reported the lipase inhibitory activity of the n-BuOH fraction of Dioscorea opposita (DOB) and its isolates. This study sought to evaluate their anti-adipogenic activity in terms of their effects on the adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) as well as phosphorylated AMP-activated protein kinase (p-AMPK) and carnitine palmitoyl transferase-1 (CPT-1). DOB apparently attenuated 3T3-L1 adipocyte differentiation (33.6% decrease at 20 µg/mL). In addition, a marked decrease (90.4%) in the expression of PPARγ was observed in the DOB-treated 3T3-L1 cells. Four isolates from DOB: (4E,6E)-1,7-bis(4-hydroxyphenyl)-4,6-heptadien-3-one (1), (3R,5R)-1,7-bis(4-hydroxy-3-methoxyphenyl)-3,5-heptanediol (2), batatasin I (3), and (1E,4E,6E)-1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (4), suppressed adipocyte differentiation by inhibiting PPARγ at 20 µM (85.9%, 68.6%, 76.2%, and 90.2% decrease, respectively) and C/EBPα (51.7%, 3.1%, 20.9%, and 59.8% decrease, respectively). Batatasin I was found to increase p-AMPK and CPT-1 at a concentration of 20 µM in 3T3-L1 adipocytes, resulting in inhibiting adipogenesis. Taken together, batatasin I might be responsible for the anti-adipogenic effect of DOB via inhibition of PPARγ and C/EBPα and activation of p-AMPK and CPT-1.