Background and Objective: Colorectal cancer is the third most common cancer in men and the second most common in women. The use of parasites or parasite antigens is one of the newest therapeutic approaches for cancer, although it has not yet been used or approved in human trials. This study aimed to determine the cytotoxic effects of purified carbohydrates from the hyaline layer, fluid, and protoscolices of hydatid cysts on the human colorectal cancer cell line (LS174T).
Methods: This descriptive-analytical study was conducted on two sheep and two cow livers infected with hydatid cysts, and the human colorectal adenocarcinoma cell line (LS174T) purchased from the Pasteur Institute of Iran at the Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran during 2022. Cyst fluid, protoscolices, and the hyaline layer were isolated from the hydatid cyst-infected livers, and glycoproteins and glycolipids from different parts of the cyst were extracted using the chloroform-methanol method. Carbohydrates were purified using the beta-elimination method and their presence was confirmed using the phenol-sulfuric acid method. The cytotoxicity of purified carbohydrates on the LS174T cell line was evaluated using the methyl tetrazolium (MTT) assay for 24 hours.
Results: Concentrations of 0.5 and 0.25 of purified carbohydrates from glycoproteins and glycolipids of hydatid cysts significantly inhibited the growth of LS174T cells (P<0.05). Initial cytotoxicity evaluation showed that purified carbohydrates from glycoproteins of sheep cyst fluid (38.60±1.33%), glycoproteins of cow cyst hyaline layer (36.61±1.76%), glycolipids of cow cyst hyaline layer (38.94±2.99%), glycoproteins of cow cyst protoscolices (40.27±3.66%), and glycolipids of sheep cyst protoscolices (37.94±1.99%) had significantly more pronounced inhibitory effects (P<0.05). Subsequent screening with the MTT assay revealed that purified carbohydrates from glycoproteins isolated from sheep hydatid cyst fluid (52.35±10.24%), glycolipids isolated from cow hydatid cyst hyaline layer (53.40±7.88%), and glycolipids isolated from sheep hydatid cyst protoscolices (53.05±5.06%) had significantly more pronounced inhibitory effects on the growth of LS174T cancer cells (P<0.05).
Conclusion: Carbohydrates isolated from glycoproteins and glycolipids of the hyaline layer, fluid, and protoscolices of hydatid cysts have significant anticancer effects on the LS174T colorectal cancer cell line.