Evaluation of the Biological Activity of Echinococcus granulosus Hydatid Cyst Antigens on HRT-18 Colorectal Cancer Cells: Cytotoxicity and DNA Damage

Abdalla, Mustafa Najim; Albayati, Nagham Y.; Mohammad, Maeda Hussain

doi:10.31557/APJCP.2026.27.8.2949

Evaluation of the Biological Activity of Echinococcus granulosus Hydatid Cyst Antigens on HRT-18 Colorectal Cancer Cells: Cytotoxicity and DNA Damage

Document Type : Research Articles

Authors

¹ Department of Biology, College of Education for Pure Sciences, University of Diyala, Diyala, Iraq.

² Experimental Therapy Department, Iraqi Center for Cancer and Medical Genetics Research, Mustansiriyah University, Baghdad, Iraq.

10.31557/APJCP.2026.27.8.2949

Abstract

Introduction: Cystic echinococcosis (CE) is a zoonotic infection caused by the larvae of Echinococcus granulosus. Studies have indicated an indirect relationship between infection with parasites and many types of cancer, especially digestive tumors. Aim: The following study aims to evaluate the anticancer activity of two antigens extracted from hydatid cyst antigens (extracted from cyst fluid and protoscoleces) of Echinococcus granulosus on the growth and proliferation of colorectal cancer cells compared to normal cells, and study their mechanism of action by DNA damage and protein expression of p53 and caspase-3. Methods: In this study, the MTT assay was used to study the anticancer effect by exposing each antigen to a range of concentrations (100, 50, 25, 12.5, 6.2, 3.1, or 0.0 µg/ml). Then, the IC₅₀ for each antigen on both the HRT-18 colorectal cancer cell line and the normal NHF cell line (normal fibroblasts derived from adipose tissue) was used to evaluate the mechanism of cell death by DNA damage and immunofluorescence staining for p53 and caspase-3 protein expression. Results: The results showed a significant decrease in the viability of colorectal cancer cells with increasing concentrations for all antigens used, with a higher effect on protoscoleces antigens (69.49%) and a slight effect on the normal cell line (21.13%). While the cyst fluid antigen showed a higher cytotoxicity (72.65%), it also showed an effect on the normal cell line (52.11%). Also, the IC₅₀ for protoscoleces and cyst fluid antigens on colorectal cancer cells were (29.93 and 24.09) µg/ml, respectively, compared with IC₅₀ for normal cells (119.4 and 25.95) µg/ml for protoscoleces and cyst fluid antigen, respectively. Therefore, treatment with the protoscoleces antigen gave the best cytotoxicity in the MTT test with more safety on the normal cell line. Also, the results showed the occurrence of programmed cell death induced by DNA damage and expression of both p53 and caspase-3 proteins in cultured cells after treatment. Conclusion: Antigens possess toxicity against cancer cells due to their ability to induce apoptosis and damage DNA; they can be considered promising sources for the development of natural antitumor agents, especially protoscoleces antigens.

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