| Plant estrogens have been associated with health benefits. Tissue cultures of mulberry species, Morus species, and Osage-orange, Maclura pomifera (Moraceae), species known to contain phytoestrogens, were established on plant-hormone supplemented Murashige and Skoog (MS) media. In vitro-obtained seedling tissues, such as epicotyl, hypocotyl and petiole and the stems and petioles from mature trees were the best explants for the initiation and proliferation of calli. Callus proliferation was obtained on MS medium containing NAA (1 mg/L) and BAP (0.5 mg/L) for mulberry and IBA (0.5 mg/L) and BAP (0.4 mg/L) for M. pomifera. The estrogenic activities of callus extracts were assayed in an estrogen-responsive yeast system expressing the human estrogen receptor alpha. Male M. alba and female M. rubra callus extracts showed the highest estrogenic activities. Isolation and characterization of phytoestrogens from the above callus extracts were carried out using SPE and HPLC chromatographic techniques. HPLC profiles of callus extracts were different from those of the mature tree extracts. This indicates that phytoestrogens in in vitro cultures are different chemicals than those isolated from the corresponding mature tissues. |
