In vitro cytotoxic and apoptotic activities of sulfated polysaccharide from Codium edule P.C. silva against breast cancer adenocarcinoma

Abstract

Objective: The primary purpose of this study is to characterize Codium edule crude sulfated polysaccharide (CSP) and its fractions and to determine its potential antiproliferative and apoptotic properties. Methods: The CSP was obtained through hot water extraction followed by precipitation with absolute ethanol. CSP was further purified using ion-exchange chromatography, Sepharose DEAE Fast Flow column and yielded three fractions (F1, F2, and F3). The CSP and fractions were characterized for their sulfate, protein, carbohydrate, and uronic acid content. Fourier-transformed infrared spectroscopy (FT-IR) was used to determine the functional groups present in CSP and SP fractions. Antiproliferative activity against human breast adenocarcinoma (MCF-7) was analyzed using MTT assay with doxorubicin as positive control. Apoptotic activity of C. edule was analyzed using caspase 3/7 and annexin V-FITC assay. Results: CSP afforded 6.3% sulfate, 4.1% protein, and 68.7% carbohydrate. F1 has the highest content of sulfate, protein, carbohydrate, and uronic acid among the fractions. FT-IR shows a broadband around 3400 cm−1 indicates the presence of hydroxyl stretching vibration of polysaccharide (-OH) and a band at 2922 cm−1 suggests a C-H stretch (alkane). 1658 cm−1 may be attributed to the C=O stretches of amide C=N group. Peak around 1259 cm−1 is a characteristic band for S=O sulfate ester. The antiproliferative activity of C. edule against MCF-7 showed significant difference in the mean percent inhibition between CSP and F3 (p=0.001), F1 and F3 (p≤0.001), F2 and doxorubicin (p=0.025), and F3 and doxorubicin (p≤0.000). F1 of C. edule has the lowest IC50 of 5.54 µg/ml and displayed apoptotic phase and caspase 3/7 activity. Conclusion: The investigation revealed that SP from green seaweed, C. edule, could be used as potential anticancer treatment against breast cancer adenocarcinoma.