A comparative study of apigenin content and antioxidant potential of Cosmos bipinnatus transgenic root culture

Flavonoid derived components have been studied for their therapeutic properties. Apigenin has shown remarkable anti-oxidant and anti-inflammatory features; however having a reliable source of apigenin is necessary. In this study the amount of apigenin in flowers, roots, leaf and stems of three varieties of Cosmos bipinnatus: Dazzler, Xanthos and Sensation pinkie and also in transgenic root culture of C. bipinnatus Dazzler was compared by HPLC method. In addition the antioxidant activity of C. bipinnatus Dazzler transgenic root culture was evaluated using FRAP assay. Dazzler variety flowers showed the highest recovery of apigenin with 0.799 mg/g DW; however the sensation pinkie variety leafs had the lowest recovery with 0.089 mg/g. Apigenin content in transformed roots (0.797 mg/g DW) of C. bipinnatus Dazzler was significantly higher than non-transformed roots (0.42 mg/g DW). The ethanolic extract of hairy root showed the FRAP value of 668.1 µM Fe2+/mg that was comparatively more than wild root FRAP value (426.2 µM Fe2+/mg). In conclusion the presence of apigenin in high amounts in hairy root cultures of C. bipinnatus Dazzler indicates its great potential for future pharmaceutical industry.