Comparative Phytochemical and Antioxidant Properties of Costus pictus and C. speciosus
Introduction: C. pictus, known as spiral ginger, an ornamental plant which has its origin in Mexico, but cultivated in Indian state of Kerala. C. speciosus could be collected from its natural habitat, but due to ruthless and indiscriminate collection it is endangered. These species are used in many of the indigenous preparation, mainly known for anti-diabetic and anti-hyperlipidaemic properties. The current study is an attempt to compare the phytochemical and antioxidant potential of the two species. Methods: Phytochemical test was carried out in order to figure out the constituents present in the two species of Costus. Further antioxidant activity was carried out in ethanolic extracts by DPPH radical scavenging assay and reducing power assay in vitro by standardised chemical methods using ascorbic acid as standard. Preliminary phytochemical tests and WHO recommended parameters of standardisation were performed. HPTLC fingerprinting profile of the leaf was also been carried out. Results: Antioxidant potential of C. speciosus and C. pictus is attributed to mainly phytoconstituents such as tannins, phenols, flavonoids. Both the species showed equally good antioxidant potential, C. speciosus was better radical scavenger in DPPH assay while C. pictus had a better reducing power. Conclusion: The study has provided evidence of good antioxidant in the species of Costus investigated.