Antidiabetic potential of phycocyanin: effects on KKAy mice.
BACKGROUND
Phycocyanin (PC) has been proven to have many therapeutic properties, but its effects on diabetes have not been investigated.


OBJECTIVE
Antidiabetic activity of PC isolated from Spirulina platensis was evaluated in this study.


METHODS
Oral administration of PC (100 mg/kg, once per day for 3 weeks) on KKAy mice were investigated by monitoring the changes in body weight, food intake, fasting plasma glucose level, 24 h random blood glucose levels, oral glucose tolerance tests (OGTTs), glycosylated serum protein (GSP), fasting serum insulin (FINS), glycogen, triglyceride (TG), total cholesterol (TC), total antioxidative capability (T-AOC) and malondialdehyde (MDA). Histopathological changes in the pancreas were also examined with hematoxylin-eosin staining.


RESULTS
Administration of PC significantly decreased the body weight, fasting plasma glucose, 24 h random blood glucose levels, FINS and GSP levels, TG and TC content in serum and livers, MDA content in livers (p < 0.05 or p < 0.01). On the other hand, glucose tolerance to glucose administration, T-AOC, and the content of glycogen in liver and muscle were enhanced following PC treatment (p < 0.05 or p < 0.01). Histopathological results showed that PC administration suppressed the abnormal enlargement of islets observed in the pancreas of KKAy mice.


CONCLUSIONS
The antidiabetic effect of PC on KKAy mice is most likely due to its ability to enhance insulin sensitivity, amelioration of insulin resistance of peripheral target tissues and regulation of glucolipide metabolism. Therefore, PC may have a potential clinical utility in combating type-2 diabetes.
School of Life Science and Technology, China Pharmaceutical University, Nanjing, China. ouyu2008@126.com
Yu
Y
Ou
Lin
L
Lin
Xuegan
X
Yang
Qin
Q
Pan
Xiaodong
X
Cheng
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D005951:Glucose Tolerance Test; D006003:Glycogen / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010798:Phycocyanin / Q000302:isolation & purification / Q000494:pharmacology*; D053545:Spirulina / Q000737:chemistry*
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D010798:Phycocyanin; D006003:Glycogen