Total phenolic content and antioxidant capacity of hydromethanolic extracts of in vitro and ex vitro plantlets of Drosera spp

Abstract

Drosera, is one of the most numerous genera of carnivorous plants. It has been reported to have pharmacological activities such as anticancer, antibacterial and anti-inflammatory. However, total phenolic content and antioxidant capacity have been poorly studied. Five specimens were in vitro propagated (D. binata, D. capensis Alba, D. capensis All Red, D. spatulata and D. spatulata x nidiformis) and acclimatized for three months. Total phenolic content (TPC) was quantified by the Folin-Ciocalteu test and the antioxidant capacity of the hydromethanolic extracts against the free radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH) was determined. In vitro plantlets of D. capensis All Red showed the highest TPC (3.32 ± 0.07 mg GAE/g) determined in dry weight. While, the highest antioxidant capacity determined in fresh weight, was obtained in D. capensis All Red and D. spatulata with 692.36 ± 66.91 and 665.14 ± 41.82 TE/g, respectively. The acclimatized plantlets of D. spatulata x nidiformis showed the highest TPC and the highest antioxidant capacity (both evaluated in fresh weight), with 6.13 ± 0.07 mg GAE/g and 1027.91 ± 4.56 TE/g, respectively. The specimen and the origin of the extracts influence the response of total phenolic content and antioxidant capacity.