Production of free and glycosylated isoflavones in in vitro soybean (Glycine max L.) hypocotyl cell suspensions and comparison with industrial seed extracts

Abstract

Glycine max is one of the major sources of phytochemicals, in particular of isoflavones, a class of phytoestrogens with ascertained beneficial effects on human health. In the present study, in vitro callus production from soybean hypocotyl seedling explants and cell suspensions were optimized. Time-courses having 20, 40 and 60 g/L of initial cell inoculum were performed to determine the concentration most suitable for isoflavone production. The amount of total polyphenols and total flavonoids as well as the antioxidant capacity of both cell and culture media fractions were measured by means of spectrophotometric methods. The levels of aglycone and glycosylated isoflavones (didzein, genistein, glycitein, didzin, genistin, glycitin), as well as of ferulic acid, vanillic acid and vanillin, were determined by HPLC-DAD. On average, 93.5 % of the total (cells plus media) isoflavones in soybean cell suspensions were detected as aglycones. Concentrated cell cultures as well as industrial soybean seed extracts were enzymatically hydrolyzed to release the aglycones and their metabolic profiles were analysed by HPLC-DAD. In contrast to cell suspensions, in undigested seed extract the aglycon form represented only 16.8 % of the total isoflavones amount. After enzymatic treatment, the antioxidant capacity increased by 30 and 33 %, respectively, in concentrated cell and seed extracts, demonstrating the presence of a larger amount of bioactive metabolites after digestion. At the present extraction conditions, soybean concentrated cell suspensions yielded 5.8fold more total isoflavones (mostly in the free form) than seed extracts, leading to hypothesise their possible use as ingredients for cosmetic and nutraceutical applications.

Methyl Jasmonate Increases Isoflavone Production in Soybean Cell Cultures by Activating Structural Genes Involved in Isoflavonoid Biosynthesis

“…Quantification of Total Flavonoid Contents. Total flavonoid contents in methanolic extracts of soybean suspension cells were quantified as described by Sansanelli et al 27 A suitable volume of methanolic extract was diluted to 400 μL with water and combined with 30 μL of 5% (w/v) NaNO 2 solution. After 5 min of incubation, 30 μL of 10% (w/v) AlCl 3 was added to the mixture.…”

Inhibitory Activity of Soy Cell Culture Extract on Tyrosinase Activity and Melanin Formation in ⍺ -MSH Induced B16-F10 Melanoma Cells

“…In the current study, the total phenolic content of soy cell extract was determined as 275 ± 13.3 µM GAE/g extract. In a similar research, Sansanelli et al [27] investigated the effect of cell inoculation rate of soy suspensions on the total amount of phenolic compounds. They reported that the highest total phenolic amount was obtained as 36.2 mg GA equivalent /L in 40 grams/L inoculated suspension.…”

Transformation and isoflavonoid analyses of suspension-cultured cells of soybean [<i>Glycine max</i> (L.) Merr. cv. Enrei]

“…Many suspension-cultured cell lines of soybean have been derived from different cultivars (Gamborg et al 1968), and their isoflavonoid contents have been analyzed (Ames and Worden 1997;Federici et al 2003;Ikeda et al 1979;Sansanelli et al 2014). Moreover, several studies have focused on the effects of biotic and abiotic stresses on isoflavonoid biosynthesis in soybean suspension-cultured cells (Akashi et al 2009;Fett and Zacharius 1982;Hille et al 1982;Kochs et al 1987;Zacharius and Kalan 1990).…”