Objective: Thymus transcaspicus (Lamiaceae) is an Iranian species of Thymus, and Ungernia trisphaera Bunge belongs to the family Amaryllidaceae. Cytotoxic properties of total ethanolic extract of T. transcaspicus and U. trisphaera were investigated against different cell lines including B16F10, PC3, U87, and MCF-7.
Methods: The proliferation, cell cycle, and migration of the cells were determined by thiazolyl blue tetrazolium bromide (MTT) test, propidium iodide (PI) staining, and scratch assay respectively. The effects of U. trisphaera extract (UTE) on the activity of matrix metalloproteinases (MMPs) and angiogenesis were evaluated by the gelatin zymography method and chicken chorioallantoic membrane model, respectively. The GSH, SOD, and MDA were evaluated by colorimetric method.
Results: The results showed that UTE could inhibit the development of malignant cells in a concentration- dependent manner, while the inhibitory effect of T. transcaspicus extract (TTE) was not significant compared to the control group. The UTE-induced sub-G1 peak apoptosis compared to the control group indicated that apoptotic cell death is involved in UTE-induced cytotoxicity. MMPs activity was significantly decreased 48 hours after treatment. Moreover, GSH level and SOD activity were significantly decreased while MDA and ROS levels were significantly increased after 24 hours treatment. In addition, combination of UTE (1.5-25 μg/mL) with doxorubicin (6 μg/mL) showed an additive cell growth inhibitory effect.
Conclusion: UTE demonstrated cytotoxic and apoptogenic effects in different cancer cell lines, and it was found that apoptosis plays a crucial role in the cytotoxicity of UTE. Thus, U. trisphaera can be considered a potential medicinal herb in cancer treatment after comprehensive pharmacological and toxicological studies.
Keywords: Thymus transcaspicus, ungernia trisphaera, cytotoxicity, apoptosis, apoptogenic.