ABSTRACT
The present study aimed to determine the bioactive profile of various extracts of Cichorium intybus L. "hairy" roots. In particular, the total content of flavonoids as well as the reducing power, antioxidant and anti-inflammatory activity of the aqueous and ethanolic (70%) extracts were evaluated. The total content of flavonoids the ethanolic extract of the dry "hairy" root reached up to 121.3 mg (RE)/g, which was twofold greater than in the aqueous one. A total of 33 diverse polyphenols were identified by the LC-HRMS method. The experimental results showed a high amount of gallic (6.103 ± 0.008 mg/g) and caffeic (7.001 ± 0.068 mg/g) acids. In the "hairy" roots, the presence of rutin, apigenin, kaempferol, quercetin, and its derivatives was found in concentrations of 0.201±0.003 - 6.710±0.052 mg/g. The broad spectrum of pharmacological activities (antioxidant, anti-inflammatory, antimutagenic, anticarcinogenic, etc.) of the key flavonoids identified in the chicory "hairy" root extract was predicted by the General Unrestricted Structure-Activity Relationships algorithm based on in the substances detected in the extract. The evaluation of the antioxidant activity showed that the EC50 values of the ethanol and the aqueous extracts were 0.174 and 0.346 mg, respectively. Thus, the higher ability of the ethanol extract to scavenge the DPPH radical was observed. The calculated Michaelis and inhibition constants indicated that the ethanolic extract of C. intybus "hairy" roots is an efficient inhibitor of soybean 15-Lipoxygenase activity (IC50 = 84.13 ± 7.22 µM) in a mixed mechanism. Therefore, the obtained extracts could be the basis of herbal pharmaceuticals for the therapy of human diseases accompanied by oxidative stress and inflammation, including the pandemic coronavirus disease COVID-19.
ABSTRACT
The aim of the study was to evaluate the long-term effect of Agrobacterium rhizogenes genes transfer on plant antioxidant system by the study of superoxide dismutase (SOD) activity in "hairy" roots of Artemisia and Althaea spp plants. PCR analyses revealed stability of the transformation and presence of bacterial rol B and rol C genes in the "hairy" roots after 4-6 years from the transformation event. SOD activity in the roots of untransformed in vitro cultivated plants used for the initiation of "hairy" roots growth was in the range of 45.8 ± 8.7 U/µg (Althaea officinalis) and 275 ± 97.1 U/µg (Artemisia ludoviciana). After a long-term in vitro cultivation more than half of tested "hairy" root lines (54%) showed a significant increase in SOD activity values compared to untransformed roots. The highest SOD activity values of "hairy" root lines (24-fold increase) were founded in A. officinalis (1105 ± 174 U/µg) and A. dracunculus (1356 ± 402 U/µg). The increase of the activity was found also in "hairy" roots of A. vulgaris (up to 375 ± 28.2 U/µg, sevenfold increase), A. ludoviciana (1001 ± 191 U/µg, 3.6-fold increase), and A. tilesii (438 ± 104 U/µg, 1.6-fold increase). The results of our study indicate that transformation by wild-type A. rhizogenes not harboring any foreign genes implementing in SOD activity regulation can often stably activate plant antioxidant enzyme system. This effect, observed in the "hairy" roots of five plant species in 4-6 years of the transformation event, obviously, should be taken into account in works aimed at creating transgenic plants by Agrobacterium-mediated transformation.
