Photodynamic Effect of Berberine Sulfate on the Growth Rate of Allium cepa Roots

Abstract

Summary Allium cepa roots were subjected to continuous treatment with different concentrations of berberine sulfate. At high dye concentrations (10 −5 and 10 −6 M), the root growth was completely inhibited, whereas at lower concentrations (10 −7 , 10 −8 and 10 −9 M), a variable degree of growth inhibition was observed. When roots treated with 10 −9 M berberine sulfate were subjected to irradiation with violet light (420 nm), the growth inhibition was complete, which points out a photodynamic activity for this drug.