Low molecular weight fucoidan ameliorates streptozotocin-induced hyper-responsiveness of aortic smooth muscles in type 1 diabetes rats.
ETHNOPHARMACOLOGICAL RELEVANCE
Low molecular weight fucoidan (LMWF) was prepared from Laminaria japonica Areschoug, a popular seafood and medicinal plant consumed in Asia. Chinese have long been using it as a traditional medicine for curing hypertension and edema.


AIM OF THE STUDY
This study was intent to investigate the possible beneficial effect of LMWF on hyper-responsiveness of aortic smooth muscles instreptozotocin (STZ)-induced type 1 diabetic rats.


MATERIALS AND METHODS
Sprague-Dawley rats were made diabetic by injection of STZ, followed by the administration of LMWF (50 or 100mg/kg/day) or probucol (100mg/kg/day) for 12 weeks. Body weight, blood glucose level, basal blood pressure, serum lipid profiles, oxidative stress, prostanoids production, and vasoconstriction response of endothelium-denuded aorta rings to phenylephrine were measured by Real time-PCR, Western blots, ELISA assay, and force myograph, respectively.


RESULTS
LMWF (100mg/kg/day)-treated group showed robust improvements on STZ-induced body weight-loss, hypertension, and hyperlipidaemia as indicated by decreased serum level of total cholesterol, triglyceride, and low density lipoprotein cholesterol; while probucol, a lipid-modifying drug with antioxidant properties, displayed mild effects. In addition, LMWF appreciably ameliorated STZ-elicited hyper-responsiveness and oxidative stress in aortic smooth muscles as indicated by decreased superoxide level, increased glutathione content and higher superoxide dismutase activity. Furthermore, administration with LMWF dramatically prevented cyclooxygenase-2 stimulation and restored the up-regulation of thromboxane synthase and down-regulation of 6-keto-PGF1α (a stable metabolic product of prostaglandin I2) in the STZ-administered rats.


CONCLUSION
This study demonstrates for the first time that LMWF can protect against hyperlipidaemia, hypertension, and hyper-responsiveness of aortic smooth muscles in type 1 diabetic rat via, at least in part, amelioration of oxidative stress and restoration of prostanoids levels in aortic smooth muscles. Therefore, LMWF can be a potential adjuvant treatment against cardiovascular complications in type 1 diabetes.
['Liang|Zhengyang|Z|', 'Zheng|Yuanyuan|Y|', 'Wang|Jing|J|', 'Zhang|Quanbin|Q|', 'Ren|Shuang|S|', 'Liu|Tiantian|T|', 'Wang|Zhiqiang|Z|', 'Luo|Dali|D|']
D000818:Animals D000959:Antihypertensive Agents D001013:Aorta, Thoracic D015415:Biomarkers D001786:Blood Glucose D003921:Diabetes Mellitus, Experimental D003922:Diabetes Mellitus, Type 1 D003925:Diabetic Angiopathies D004305:Dose-Response Relationship, Drug D005978:Glutathione D006949:Hyperlipidemias D006973:Hypertension D000960:Hypolipidemic Agents D008055:Lipids D008297:Male D008970:Molecular Weight D009131:Muscle, Smooth, Vascular D018384:Oxidative Stress D011134:Polysaccharides D011453:Prostaglandins D017207:Rats, Sprague-Dawley D015398:Signal Transduction D013311:Streptozocin D013482:Superoxide Dismutase D013481:Superoxides D014664:Vasodilation D015430:Weight Gain
Fucoidan Diabetes Hypertension Aorta Vascular smooth muscles