In Vitro Antiproliferative Effect of Angiopteris evecta (G. Forst.) Hoffm. Extracts against Cultured HT-29 Colon Cancer Cells

Abstract

Angiopteris evecta (G. Forst.) Hoffm. belongs to the family Angiopteridaceae. It is commonly called giant or king fern. The plant is used as a traditional medicine and as diuretic, antipyretic, tonic, analgesic, antihelminthic, and antidiarrheal. The present study investigated the antiproliferative activity of A. evecta ethanolic extracts against malignant colon cancer cells (HT-29) and nonmalignant colon cancer cells (L929). The anticancer activity of A. evecta revealed that its extracts are effective against HT-29 colon cancer cells and they do not harm the L929 cells. Cytotoxicity against cell lines showed the great difference between malignant and nonmalignant cell lines, and they inhibit the cancer cells even at low concentration of 15.94 μg/ml. The inhibition concentration (IC50) value of the ethanolic extract of A. evecta (G. Forst.) Hoffm. treated HT-29 cancer cells at 24 h was 15.94 μg/ml and of L929 cells 81.69 μg/ml. Results showed apoptotic effect of A. evecta ethanolic extracts against HT-29 cancer cells in a dose-dependent manner. The apoptotic effect was confirmed by the double staining method and was observed under fluorescent spectroscopy, which revealed the apoptotic and viable cells by their fluorescence. Untreated control cells showed cells with Acridine orange stained green nucleus. In malignant cells, early and late apoptotic cells were observed in 9.5 μg/ml extract, and necrosis resulted in 21.5 μg/ml extract, and necrotic cells appeared as red stained nuclei, and thus necrosis increases as the concentration increases. DNA content and cell cycle was studied by flow cytometry. HT-29 cells treated with A. evecta. Showed the DNA damage or loss of DNA content in the sub G0/G1 phase, S-phase, and G2/M phase. From the results, it is very clear that maximum apoptosis took place in the G0/G1, and it is proven through the population profile index. The cell size of the treated and untreated HT-29 cells differs, and moreover untreated HT-29 cells showed less population in sub G0/G1 phase, whereas in treated HT-29 cells, the population was noticed high in the G0/G1 phase than the S-phase. Hence, the results indicated that the ethanol extract of A. evecta plant extract has the potential antiproliferative activity with low cytotoxicity to normal cells. Our results support the ethnomedicinal observations of these plants for the management of cancer. Future study is needed about the active elements in the extracts, to be isolated and purified to investigate the synergy and additive pharmacological effect in killing cancer cells.