“Hairy” root culture of medicinal plants as a source of biologically active compounds: from laboratory to pharmacy

Abstract

Plant-mediated “green” synthesis of compounds with medicinal properties attracts great interest for many years. “Hairy” root cultures can synthesize numerous compounds including phenols, flavonoids, essential oils, sugars etc. The possibility to increase the amount of these compounds due to transfer of rol genes from Agrobacterium rhizogenes was confirmed. In this work we compared the effect of rol genes transfer on the flavonoids accumulation and spectrum, antioxidant activity of the extracts from the root cultures of Artemisia spp, Bidens pilosa, Cichorium intybus medicinal plants. “Hairy” root cultures were obtained after A. rhisogenes A4 wild strain transformation and were subcultured in in vitro conditions. HPLC method to identify and quantify flavonoids in plant-derived extracts was used. Antioxidant activity was measured by the scavenging of DPPH* radical. Expression of pal and chs genes coding biosynthesis of flavonoids was studied by Real-Time PCR. Increase of the total flavonoid content up to 140 mg/g DW as well as the increase of antioxidant activity were found in the “hairy” root cultures for all plants studied. The increase of flavonoids content correlated with the expression of pal and chs genes. Kaempherol, rhamnetin, silibinin, luteolin, epicatechin, casticin, apigenin known by their anticancer activity were identified in the ethanolic extracts. Propagation of “hairy” root cultures in a liquid bioreactor allowed us to enlarge root biomass without addition of growth regulators. So, we selected “hairy” root cultures of medicinal plants which can be cultivated in bioreactors and used for production of the compounds with antioxidant and anticancer activity.