摘要
Objective:To investigate the antioxidant and cytotoxic properties of the most active extracts from Ulva lactuca and Laurencia obtusa against colon and cervical cancer cell lines.Methods:The antioxidant radical scavenging activity of the algal extracts was estimated using the 2,2-diphenyl-1-picrylhydrazyl colorimetric assay.Moreover,the cytotoxic potential of these bioactive extracts was studied against HCT-116 and HeLa cells by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay.Wound healing analysis was adopted to evaluate the antimetastatic effects of protein extracts from both algae.Cell cycle analysis was performed by flow cytometry,and apoptotic bodies were detected using 4′,6-diamidino-2-phenylindole fluorescent staining.Amino acids of hydrolyzed protein extract were separated and identified chromatographically by high performance liquid chromatography.Results:The green algae Ulva lactuca had higher lipid content than Laurencia obtusa,whereas the latter had higher protein content with high antioxidant capacity.Protein extracts had significant dose-and time-dependent cytotoxicity and anti-metastatic activity against HCT-116 cells.Protein b extracts of both algae obtained from the chloroform:hexane solvent lipid-free residue caused morphological changes and induced apoptosis of HCT-116 cells.Further analysis revealed that apoptosis induced upon Laurencia obtusa protein b treatment was triggered via the ROS pathway,causing a significant increase in the sub-G_(1) population.Glycine and arginine(5.94 and 5.47μM,respectively)were the most common amino acids in Laurencia obtusa protein b extract.Conclusions:Proteins of Laurencia obtusa and Ulva lactuca could be considered as an adjuvant nutraceutical source of pro-apoptotic and anti-metastatic biomolecules against colon cancer.
