Effects of UV B and UV C radiation on viability, growth, and major natural compounds of Malve neglecta L. cells

Callus cultures were established in vitro from leaf explants of Malva neglecta and were sub-cultured several times until a rapid-growing cell line was obtained. The calluses were exposed to different doses of ultraviolet (UV) radiation as follows: 0, 432, 864, and 1296 J/m2 for UV B and 0, 612, 1284, and 1836 J/m2 for UV C, corresponding to 0, 30, 60, and 90 min radiations, in tandem. Exposure to UV, in particular for longer periods, reduced the viability and membrane integrity of Malva cells. This however, increased total contents of flavonoids, anthocyanins, and wall-bound phenolic acids. Among different pharmaceutical compounds of Malva cells increase of malvidin, catchin, cinnamic acid, and tannic acid was remarkable in UV-treated cells, compared to those of the control cells. According to the results, treatment of Malva cells with UV provides an attractive alternative to whole plants for effective production of specific phenolic compounds.