The Juice of Asparagus By-Product Exerts Hypoglycemic Activity in Streptozotocin-Induced Diabetic Rats

Abstract

The woody ends of asparagus (Asparagus officinalis L.) spears contain various bioactive substances. However, they are often discarded as by-products. We extracted juice from recycled woody stems of asparagus (AJ) to investigate its hypoglycemic effect in a streptozotocin-induced diabetic rat model. The diabetic rats showed significant decreased fasting serum glucose, glycosylated serum protein and malondialdehyde levels after 21 days of AJ treatment. Moreover, the oral glucose tolerance test revealed that AJ treatment can significantly reduce rat blood glucose level at 30, 60 and 120 min after glucose loading. These results demonstrated the hypoglycemic activity of AJ and its potential therapeutic use in preventing diabetic complications associated with hyperglycemia and oxidative stress. Practical Applications Asparagus, a healthy and nutritious vegetable, is commonly consumed in many regions of the world. In addition to its edible value, this plant has been reported to possess various biological activities. During harvest, the woody ends of asparagus, around 30–40% of each spear, are usually discarded as by-product. In fact, this by-product has been reported to be rich in many bioactive phytochemicals. In the current study, we identified that juice from woody stems of asparagus (AJ) exerted potential hypoglycemic activity in streptozotocin-induced diabetic rats. We found that oral administration of AJ significantly decreased the elevated levels of fasting serum glucose, glycosylated serum protein and serum malondialdehyde in diabetic rats. Moreover, we found AJ could improve the impaired glucose tolerance in diabetic rats. Overall, our findings suggest that AJ might have potential usage in food supplements for its therapeutic effects.