Abstract:

Objective: To extract and purify water-soluble polysaccharide from fresh litchi flesh (WSPLF), and then to
observe blood glucose-lowering effect of WSPLF in alloxan-induced diabetic mice. Methods: Water-soluble polysaccharide
was extracted by water extraction method from litchi flesh, and subjected to protein removal, deionization, and freeze drying.
In SPE level NIH mice, alloxan was intraperitoneally injected at a dose of 200 mg/kg to establish diabetic model. Control
group (fed distilled water), glibenclamide group (15 mg/(kg·d)), low-dose WSPLF group (200 mg/(kg·d)), middle-dose
WSPLF group (400 mg/(kg·d)) and high-dose WSPLF group (800 mg/(kg·d)) were set up. Fasting body weight, blood
glucose, liver glycogen, hemoglobin and other indicators were measured at different time points during the administration
of WSPFL. Results: Three days after the injection of alloxan, the body weight of NIH mice revealed an obvious decrease
when compared with glibenclamide group. Meanwhile, the blood glucose was significantly reduced after the administration
of high-dose WSPLF for 3 weeks (P ＜ 0.05) when compared with glibenclamide group. Moreover, the liver glycogen of
mice was significantly reduced after 3-week administration of WSPLF, and did not reach the normal level (P ＜ 0.01) when
compared with glibenclamide group. Glycosylated hemoglobin in mice fed WSPLF at the middle or high dose also revealed
a significant difference compared with glibenclamide group (P ＜ 0.05). Conclusion: WSPLF has blood glucose-lowering
effect in diabetic mice.

Key words: litchi flesh water-soluble polysaccharide, diabetes, blood glucose, liver glycogen, glycosylated hemoglobin