Effect of alpha lipoic acid on oxidative stress and vascular wall of diabetic rats.
PREMISES AND OBJECTIVES: Antioxidant plays an important role in preventing the progression of diabetes mellitus (DM) complications. The aim of the present study was to investigate the effect of alpha lipoic acid (ALA) supplementation on plasma lipid, oxidative stress and vascular changes in diabetic rats.


METHODS
Diabetes was induced by a single intravenous injection of streptozotocin (STZ) (50 mg/kg). The diabetic rats were divided into two groups: (i) supplemented group with ALA (100 mg/kg/day) and (ii) non-supplemented group without ALA. Non-diabetic rats (NDM) formed the control group, which received saline injection.


RESULTS
Following eight weeks of supplementation, fasting blood glucose (FBG) and glycosylated hemoglobin (HBA1c) in ALA-supplemented rats was found to be significantly lower than the non-supplemented group. ALA-supplementation also improved dyslipidemia that occurred in diabetic rats. ALA-supplementation also significantly increased plasma superoxide dismutase (SOD) activity and vitamin C level as compared to the No Suppl group. The increase in plasma and aorta malondealdehyde + 4-hydroxynonenal (MDA + 4-HNE) levels were also inhibited and the levels of oxidative DNA damage of peripheral lymphocytes were significantly reduced. Electron microscopic examination of thoracic aorta revealed that normal tissue organization was disrupted in STZ-diabetic rats with ALA-supplementation reducing the changes in the vascular morphology.


CONCLUSIONS
It is concluded that ALA has the potential in preventing the alteration of vascular morphology in diabetic rats probably through the improvement of glycemic status and dyslipidemia as well as its antioxidant activities.
Balkis Budin
Siti
S
Biomedical Department, Faculty of Allied Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia. amira@medic.ukm.my
Othman
Faizah
F
Louis
S R
SR
Abu Bakar
M
M
Radzi
M
M
Osman
K
K
Das
S
S
Mohamed
J
J
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology* / Q000648:ultrastructure; D001205:Ascorbic Acid / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D006442:Glycated Hemoglobin / Q000378:metabolism; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology* / Q000648:ultrastructure; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D008063:Thioctic Acid / Q000494:pharmacology*; D017540:Tunica Media / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology / Q000648:ultrastructure
D001205:Ascorbic Acid; D001786:Blood Glucose; D002784:Cholesterol; D006442:Glycated Hemoglobin; D008063:Thioctic Acid