Combined UV-C irradiation and precursor feeding enhances mulberroside A production in Morus alba L. cell suspension cultures

Mulberroside A is a major bioactive compound produced by Morus alba L., a medicinal plant of the family Moraceae that is used in traditional medicines and supplementary health products for various indications. In this study, cell suspension cultures of M. alba that produced mulberroside A and other phytochemicals were treated with 20 min UV-C irradiation to investigate the effect of time after UV-C treatment on levels of mulberroside A, oxyresveratrol, resveratrol, and rutin. The amount of mulberroside A produced from cell suspension cultures of M. alba that were treated with UV-C was significantly higher than the control. However, there were no significant differences in the levels of oxyresveratrol, resveratrol, and rutin. The effect of UV-C in combination with precursor feeding on phytochemical production of cell suspension cultures of M. alba was investigated. L-phenylalanine and L-tyrosine were used as precursors. The addition of 0.05 mM L-phenylalanine 5 d prior to UV-C irradiation doubled the content of mulberroside A in cell suspension cultures of M. alba as compared to the non-irradiated and untreated cells. The use of precursor feeding in combination with UV-C irradiation could be an alternative method for the production of mulberroside A in M. alba.