Hypoglycemic activity of polysaccharide, with antioxidation, isolated from cultured Cordyceps mycelia.
Cordyceps sinensis, a well-known traditional Chinese medicine, possesses anti-tumor, immunostimulant and antioxidant activities; however, the identities of active components have not been determined. In our previous study using antioxidant activity-guided fractionation [Li et al., 2003. A polysaccharide isolated from Cordyceps sinensis, a traditional Chinese medicine, protects PC12 cells against hydrogen peroxide-induced injury. Life Sci. 73, 2503-2513], a polysaccharide of molecular weight approximately 210kDa was isolated from cultured Cordyceps mycelia by ion-exchange and sizing chromatography. The isolated polysaccharide, named CSP-1, which has strong anti-oxidation activity, contains glucose, mannose and galactose in the ratio of 1:0.6:0.75. In the present study, we demonstrated the hypoglycemic effect of CSP-1 on normal and alloxan-diabetic mice and streptozotocin (STZ)-diabetic rats. The basal glucose level did not differ significantly among the normal mice. CSP-1 (at 200 and 400mg/kg body wt./day for 7 days, p.o.), however, significantly reduced the blood glucose level by 12.0+/-3.2% and 22.5+/-4.7% in normal mice, respectively (p<0.05). When administered at a dose of higher than 200mg/kg body wt. daily for 7 days, CSP-1 produced a significant drop in blood glucose level in both STZ-induced diabetic rats and alloxan-induced diabetic mice. The serum insulin levels in diabetic animals were also increased by administration of CSP-1 (p<0.05). CSP-1 with hypoglycemic properties increased circulating insulin level in diabetic animals, which suggests that CSP-1 may stimulate pancreatic release of insulin and/or reduce insulin metabolism.
Li
S P
SP
Institute of Chinese Medical Sciences, University of Macau, Taipa, China. spli@umac.mo
Zhang
G H
GH
Zeng
Q
Q
Huang
Z G
ZG
Wang
Y T
YT
Dong
T T X
TT
Tsim
K W K
KW
D000284:Administration, Oral; D000496:Alloxan; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use; D032661:Cordyceps; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000517:prevention & control*; D005947:Glucose / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008517:Phytotherapy; D011134:Polysaccharides / Q000008:administration & dosage / Q000627:therapeutic use; D051381:Rats; D013311:Streptozocin
D000975:Antioxidants; D007004:Hypoglycemic Agents; D007328:Insulin; D011134:Polysaccharides; D013311:Streptozocin; D000496:Alloxan; D005947:Glucose