Anti-diabetic effects of chondroitin sulfate on normal and type 2 diabetic mice

We evaluated the inhibitory effects of CS with different molecular weights from 170,000 to 10,000 Da on a-glucosidase activity in vitro. Low-molecular-weight CS (< 16,000 Da) showed a higher inhibition of a-glucosidase activity than high-molecular-weight CS. In addition, we examined the effects of a single administration of low-molecular-weight CS on postprandial blood glucose in ICR mice. Low-molecular-weight CS inhibited the elevation of postprandial blood glucose in mice loaded with sucrose or starch as the source of carbohydrates. Finally, we investigated the anti-diabetic effects of daily administration of low-molecular-weight CS using type 2 diabetes model KK-Ay mice. The elevation of fasting blood glucose was inhibited in the CS group. These results suggest that the administration of low-molecular-weight CS prevents the elevation in the postprandial blood glucose level by reducing the digestion of carbohydrates in the gastrointestinal tract, leading to reductions of hyperglycemia in KK-Ay mice.