The effects of the anthocyanin-rich extract from red cabbage leaves on Allium cepa L. root tip cell ultrastructure

Abstract

The effect of exogenously applied 250 μM anthocyanin-rich (ATH-rich) extract from red cabbage leaves on the ultrastructure of Allium cepa root meristematic cells was investigated. The tested extract slightly affected mitochondria, endoplasmic reticulum (ER), Golgi apparatus and vacuoles. In the presence of ATH, 62% of mitochondria converted to condensed type. In addition swollen, circular ER cisternae were sporadically observed. In the ATH-treated roots, one third of Golgi structures was characterized by the reduced number of vesicles. Moreover in 54% of vacuoles, the electron-dense granular and circular material appeared. Additionally, in the cytoplasm, the presence of numerous multivesicular bodies (MVB) was noticed. The observed ultrastructural modifications of mitochondria, and presumably also ER, probably resulted from the ability of an ATH to affect mitochondrial respiratory activity. The other changes in A. cepa root meristematic cell ultrastructure were connected with the transport of exogenously applied ATH into vacuoles. It seems that they are transported from the plasmolemma to the vacuole by multivesicular bodies (MVB), and there trapped by anthocyanic vacuolar inclusions (AVIs). However, none of the observed ultrastructural changes seemed to disturb cell functions, therefore the ATH-rich extract from red cabbage leaves may be regarded as cell-friendly and can be safely used as a detoxifying agent against heavy metal poisoning, as it is more and more often postulated.