Antioxidant is a basic requirement for maintaining good health and antidiabetic is very important for maintaining blood glucose level of diabetes mellitus patients. In this research, natural compounds were extracted from Curcuma xanthorrhiza (Javanese turmeric). The compounds were extracted using ultrasonic assisted extraction (UAE) for in-vitro antidiabetic and antioxidant studies. The extracts were analysed using amylase inhibitory assay and DPPH radical scavenging assay. Finally, the alpha amylase inhibitor of the extracts was studied to identify the mode of inhibition. From the result obtained, the rhizome extract of C. xanthorrhiza showed the higher antioxidant activity in comparison to the leaves extract of the plant. As for antidiabetic activity, maximum of 70% was observed at 100μg/ml which was compared with that of the standard, Acarbose that indicated 72% inhibition. The IC50 (Half-Maximal Inhibitory Concentration) of the rhizome extract was found to be 0.4417 and for Acarbose 0.9256. The mode of amylase inhibition exhibited a pattern of competitive inhibition. These results have proven that C. xanthorrhiza is a potentially useful herbal candidate for treatment of diabetic and other diseases related to free radicals.
