Nutritional composition, [alpha]-glucosidase inhibitory and antioxidant activities of Ophiopogon japonicus tubers

Ophiopogon japonicus tubers have been widely used as food and traditional Chinese medicine in China. However, their nutritional composition has not been fully reported yet. This study aimed to analyze the nutritional composition of O. japonicus tubers. The [alpha]-glucosidase inhibitory and antioxidant activities of the extracts obtained from O. japonicus tubers were also evaluated by in vitro assays. The results indicated that O. japonicus tubers are rich in carbohydrates, proteins, minerals, and amino acids. Among four extracts, the n-butanol fraction (nBF) and chloroform/methanol extract (CME) of O. japonicus tubers had high amounts of total phenolic and flavonoid contents and exhibited good [alpha]-glucosidase inhibitory and antioxidant activities. The [alpha]-glucosidase inhibition of nBF was higher than acarbose. Overall, O. japonicus tubers are full of nutritional compounds and have good aglucosidase inhibitory and antioxidant activities.