Phenylalanine Increases the Production of Antioxidant Phenolic Acids in Ginkgo biloba Cell Cultures

Abstract

The aims of this study were to evaluate the antioxidant properties, to investigate the content of major secondary metabolites in Ginkgo biloba cell cultures, and to determine the change in the production of phenolic acids by adding phenylalanine to the culture medium. Three in vitro methods, which depend on different mechanisms, were used for assessing the antioxidant activity of the extract: 1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe2+ chelating activity assays. The extract showed moderate activity both in the DPPH and in the reducing power assays (IC50 = 1.966 ± 0.058 mg/mL; ASE/mL = 16.31 ± 1.20); instead, it was found to possess good chelating properties reaching approximately 70% activity at the highest tested dose. The total phenolic, total flavonoid, and condensed tannin content of G. biloba cell culture extract was spectrophotometrically determined. The phenolic acid content was investigated by RP-HPLC, and the major metabolites—protocatechuic and p-hydroxybenzoic acids—were isolated and investigated by 1H NMR. The results showed that phenylalanine added to G. biloba cell cultures at concentrations of 100, 150, and 200 mg/150 mL increased the production of phenolic acids. Cultures that were grown for 3 weeks and collected after 4 days of phenylalanine supplementation at high concentration showed maximal content of phenolic acids (73.76 mg/100 g DW).

Antioxidant Potential and Enhancement of Bioactive Metabolite Production in In Vitro Cultures of Scutellaria lateriflora L. by Biotechnological Methods

“…Phenylalanine concentration 0.75 g/L highly stimulated quercetin production in a callus culture of Abutilon indicum [ 43 ]. In cell cultures of Ginkgo biloba increased levels of gallic, protocatechuic and p-hydroxybenzoic acids were detected after administration of 0.66–1.33 g/L Phe [ 44 ]. Verbascoside biosynthesis, in contrast, was activated in cell suspension cultures of Buddleja cordata by the addition of 100 mg/L of Phe [ 45 ].…”

The Influence of Exogenous Phenylalanine on the Accumulation of Secondary Metabolites in Agitated Shoot Cultures of Ruta graveolens L.

“…In the study on the accumulation of bioactive metabolites in agitated cultures of Scutellaria lateriflora , authors used various concentrations of the precursor PheAla (1–2.5 g/L) and found that the optimal concentration of phenylalanine that did not cause inhibition of biomass growth was 1.5 g/L [ 15 ]. Skrzypczak-Pietraszek E. et al confirmed that a phenylalanine concentration of 1.6 g/L was the most advantageous in agitated cultures of Vitex agnus castus [ 16 ]. On the other hand, Szopa et al proved that, at concentrations in the range of 0.0165–0.165 g/L, phenylalanine did not inhibit the increase in the biomass of agitated cultures of two Aronia spp., while, at higher concentrations (0.825–1.65 g/L), it inhibited biomass growth [ 13 ].…”

“…In a study on Rhodiola imbricata cell suspension cultures, the addition of phenylalanine at different concentrations (0.5–3 mM) caused an increase in the production of rosavin, rosarin, and p -coumaric acid [ 38 ]. In a study on V. agnus castus shoot cultures, the addition of phenylalanine at a dose of 1.6 g/L led to increased production of phenolic acids and flavonoids [ 16 ]. In a study of S. lateriflora shoot cultures, feeding with phenylalanine at a concentration of 1.5 g/L was found to be the best strategy to increase the production of flavonoids and verbascoside [ 15 ].…”

“…Additionally, the study analyzed the effect of phenylalanine on the accumulation of other bioactive compounds, namely furanocoumarins and furoquinoline alkaloids. Feeding with phenylalanine in in vitro cultures has often resulted in high production of phenolic compounds [ 13 , 14 , 15 , 16 ]. Phenylalanine is a basic precursor of different phenolic metabolites in plants.…”

Using the Strategy of Inducing and Genetically Transforming Plant Suspension Cells to Produce High Value-Added Bioactive Substances

“…Besides, the monocotyledonous plant suspension cells reported include Veratrum california , Vanilla planifolia , Fritillaria cirrhosa , Dioscorea deltoidea , and Crocus sativus , etc. Gymnosperms are more difficult to induce than angiosperms because they are less sensitive to induction, and only few reports have been published so far, such as Taxus chinensis , Ginkgo biloba , Pinus pinaster . Taxus transgenic suspension cells have obtained a large amount of paclitaxel, a secondary metabolite with anticancer activity …”