Production of dihydroxylated betalains and dopamine in cell suspension cultures of Celosia argentea var. plumosa

Abstract

Betalains are plant pigments of hydrophilic nature with demonstrated chemopreventive potential in cancer celllines and animal models. Among the betalains, those containing an aromatic moiety with two free hydroxyl groups possess thestrongest antioxidant and free radical scavenging activities. The betaxanthins dopaxanthin and miraxanthin V and the betacyaninsbetanidin and decarboxy-betanidin are the only natural betalains with catecholic substructures. These four pigments have beenproduced in cell cultures established from hypocotyls of the plant Celosia argentea. Two stable and differentially colored cell lines,yellow and red, were maintained on Murashige and Skoog medium supplemented with the plant growth regulators 6-benzylaminopurine (6.66 μM) and 2,4-dichlorophenoxyacetic acid (6.79 μM). Derived suspension cultures showed increasedproduction of dihydroxylated betalains in the cells and secreted to the medium with a maximum reached after 8 days of culture.In addition, precursor molecules betalamic acid and dopamine, with content up to 42.08 mg/g dry weight, were also obtained.The joint presence of the bioactive betalains together with the production of dopamine and betalamic acid show the ability of cellcultures of C. argentea to become a stable source of valuable phytochemicals