Background: The extent of morphological and ultrastructural changes in HeLa cells was assessed by optical, fluorescence and electron microscopy after exposure to various concentrations of physcion, taking into account the biological properties of the test compound. Methods: Cell viability was assessed by MTT assay, while the cell cycle, LC3 expression, apoptosis, change of mitochondrial potential, Bcl-2 protein expression level and the level of reactive oxygen species were analyzed by flow cytometry. Results: As a result of physcion encumbrance, concentration-dependent inhibition of HeLa cell viability and the G0/G1 phase of the cell cycle was observed. Activation of the lysosomal system was also revealed, which was expressed by an increased number of lysosomes, autophage vacuoles and increased expression of the LC3 protein, a marker of the autophagy process. Transmission electron microscopy and fluorescence microscopy showed that physcion induced clear changes in cervical cancer cells, especially in the structure of the nucleus and mitochondria, which correlated with the production of reactive oxygen species by the test compound and indicated the induction of the oxidative process. At the same time, the pro-apoptotic effect of physcion was demonstrated, and this mechanism was dependent on the activation of caspases 3/7 and the reduction in Bcl-2 protein expression. Conclusion: The obtained results indicate an antitumor mechanism of action of physcion, based on the induction of oxidative stress, autophagy and apoptosis.

Background: Anthraquinones, including emodin, are compounds with numerous pharmacological properties, including anticancer properties. The aim of this study experiment was to examine the effect of emodin, a natural compound present in the roots and rhizomes of Rheum palmatum, on the induction of mitotic catastrophe in cervical cancer cells. Material and Methods: HeLa celIs were treated with different emodin concentrations for 48 h, and cell growth was measured with 3-(4-,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolyl. The cell-cycle distribution and the level of apoptosis were determined by means of flow cytometry, using annexin V-fluorescein isothiocyanate staining and propidium iodide. Morphological changes in the mitotic apparatus were evaluated using optical and confocal microscopy techniques. Results: Emodin induced an increase in the number of polymorphonuclear cells, giant cells, cells with micronuclei, cells with abnormal mitosis and damaged spindle. The reorganization of F-actin depended on the concentration of emodin. With the increase in emodin concentration, inhibition of mitotic activity was demonstrated, which was manifested by a decrease in the mitotic index, mainly in metaphase of the mitotic process and an increase in the number of cells inhibited in the G 2 /M phase. At the same time, an increase in the number of apoptotic cells was found. Conclusion: Emodin leads to death of cervical cancer cells by induction of a mitotic catastrophe.

Chrysophanol is an anthraquinone with proven antitumor activity against several tumor cell lines. However, its effect on cervical cancer cells is still unknown. Therefore, HeLa cells were exposed to various concentrations of chrysophanol and then subjected to biochemical, ultrastructural, and morphological analysis. It has been shown using flow cytometry and MTT reduction assay that chrysophanol has been shown to inhibit cell viability and arrest cells in the G2/M phase of the cell cycle. Using Annexin V/propidium iodide staining, a significant increase in apoptosis was found after chrysophanol treatment on HeLa cells, and this process was mediated by caspases 3/7 with a clear inactivation of the antiapoptotic Bcl‐2 family protein. However, the demonstrated increased number of cells with double‐stranded DNA breaks suggests that chrysophanol also causes DNA damage. By means of electron and fluorescence microscopy, a clear effect of chrysophanol on the intensification of degradation processes, on changes in the structure of the nucleus, endoplasmic reticulum and mitochondria was demonstrated. The changes visible in the mitochondria may be related to the increase in the level of free radicals induced by chrysophanol, which induces apoptosis, inter alia, by increasing the permeability of mitochondrial membranes. The range of observed changes depended on the concentration of anthraquinone was tested.

Emodin induces degradation processes and promotes the death of tumor cells through a mechanism that occurs with clear involvement of the lysosomal compartment.

Aloe-emodin induces mitotic catastrophe in cervical cancer cells.