Investigation of Bioactivities and Physicochemical Properties of Four Different Curcuma Species Available in Sri Lanka

To enhance the value of the unexplored medicinal herbs in Sri Lanka, this study was focused on the physicochemical analysis and investigation of biological activities of four different Curcuma species abundantly dispersed in Sri Lanka namely, Curcuma albiflora Thwaites, Curcuma aromatica Salisb., Curcuma longa L. and Curcuma zedoaria Roxb. Many species in genus Curcuma were rich with phenolic compounds. The total phenolic content (TPC) of dried rhizomes of Curcuma longa was the highest of all (5.530 g of GA equivalents/1 g of dried rhizome). The average antioxidant properties in the DPPH test was reported in MeOH extracts of the rhizome and leaf samples of four species. Further the MeOH extracts exhibited the inhibitory activities toward α-amylase enzyme with IC50 values ranging from 6.455 μg/ml to 307.475 μg/ml. The present study shows that Sri Lankan Curcuma species have a potency to be used as antioxidant and antidiabetic agents. This information particularly physicochemical constants such as moisture content, total ash, acid insoluble ash and water-soluble ash values will be helpful in standardization of quality, purity and authentication of these medicinal plants for preventing its raw materials adulteration.