Catharanthus roseus is the source of important anti-cancer drugs, vincristine and vinblastine, which are produced in very low yields requiring huge quantities of the whole plant and extensive chromatographic processing for their isolation. Root suspension cell cultures of C. roseus produced alkaloids when the media concentration of growth hormone 2,4-D was reduced. Several workers have reported the influence of relative hormonal content of the medium upon secondary metabolite production.

In general, an increase in auxin level, such as 2,4-D, stimulates cell proliferation and reduces secondary metabolite production. Cytokinins reportedly enhance secondary metabolite accumulation and gibberellins in general inhibit it.

Thalictrum minus cell cultures showed good cell growth in the presence of 2,4-D and showed enhanced berberine production with ethylene or NAA and BAP or a cytokinin. On the other hand, cardenolide content in D. lanata cultures decreased with ethylene.