Mass production of coumestrol from soybean (Glycine max) adventitious roots through bioreactor: effect on collagen production

Coumestrol (CMS), one of the soybean isoflavonoids which contains several benefits for maintaining skin function including antiageing properties. In this study, we evaluated various explant sources and plant genotypes to determine competent soybean adventitious root materials for the mass production of CMS, and investigated their skin care efficacies to be used as a novel cosmetic ingredient. Adventitious roots were directly induced from in vitro seedling derived from the mature seeds, extracts were prepared and refluxed for enzymatic deglycosylation. In vitro cell cytotoxicity was evaluated using normal human dermal fibroblast and murine B16 melanoma cells after treatment with increasing concentrations of methanol soybean adventitious roots extracts for 72 h. Finally, in vitro cell assays on HDF cells were performed to evaluate the effect of the soybean adventitious roots extracts in collagen production. The root induction frequency and biomass productivity were significantly affected by plant genotypes, explant sources, the type of auxin used and its concentration. The total CMS production (per 1 L medium) after 4 weeks of culture in a bulb-type bubble bioreactor (3 L capacity) was the highest in the adventitious roots induced from the radicles of Glycine max, ‘Sinhwakong’. Different strengths of Murashige and Skoog (MS) medium were tested to develop culture protocols and the highest total CMS production (per 1 L medium) was observed at 1/2 MS. The content of coumestrin, the glycoside form of CMS, was higher than that of CMS in the roots cultured in 1/2 MS medium for 4 weeks in a bioreactor. The final content of CMS in the ethanol extract after enzymatic deglycosylation was 81.3-fold higher than non-enzymatic deglycosylation. Almost all the coumestrin in the roots were converted to CMS. Further, the enriched CMS root did not exhibit any cell cytotoxicity in normal human dermal fibroblast (HDF) and murine B16 melanoma cells (B16) for 72 h. In addition, in vitro collagen production assay on HDF cells showed that the enriched CMS root increased the collagen production compared to the coumestrol, daidzein, and non-enzyme-treated sample. Thus, enriched CMS root could be potential ingredient for the cosmetic applications