Effects of UV-B and DMSO Treatments on the Production of Artemisinin in Low-Artemisinin Producing Artemisia annua Cell Cultures

Artemisinin is a sesquiterpene lactone derived from Artemisia annua L., and has a variety of biological properties, such as immunoregulatory and anticancer effects, and therapeutic applications. As a result of its naturally low production and compartmentalised synthesis, the irregular agricultural supply often leads to price fluctuations and reduction of the artemisinin inventory. In this study, elicitation efficiencies of ultraviolet B (UV-B) and dimethyl sulfoxide (DMSO) on a low-artemisinin producing (LAP) chemotype of the species A. annua were investigated. Exposure of cell suspension cultures to short-term UV-B radiation and DMSO treatment did not result in significant changes in artemisinin yield. The lack of stimulation could be associated with the growth condition such as the incubation duration after treatment, the physiological state of suspension-cultured cells, and the regulation of cellular metabolic homeostasis. Further molecular analysis with RT-PCR revealed the absence of mRNA transcripts of key genes ADS, DBR2, and ALDH1 which might affect artemisinin synthesis. This study demonstrated the complexity of stress-induced responses of cell suspension cultures in relation to metabolic processes which are important for artemisinin formation.