Anticancers from selected endophytic fungi from Ratchadat Brucea javanica (L.) Merr.

Abstract

The purpose of this research was to isolate the secondary metabolites produced by the endophytic fungi from the leaves and barks of Brucea javanica (L.) Merr. and to study on their anticancer activity. Thirty-four fungal isolates were obtained from plant samples. After cultivation in five different media; potato dextrose broth (PDB), malt extract broth (MEB), malt czapek broth (MCzB), sabouraud’s dextrose broth (SDB) and glucose yeast extract broth (GYB), crude extracts were investigated their cytotoxicity against five human cancer cell lines; hepato carcinoma (Hep-G2), colon carcinoma (SW-620), lung carcinoma (CHAGO), gastric carcinoma (KATO-3) and breast carcinoma (BT-474). Based on the results of cytotoxicity and 1H NMR spectral data of crude extracts, RB-20/2A, RB-20c and RL-K3 grown in MEB, were selected to further cultivate for isolating cytotoxic compounds. The fractionation of their extracts led to the isolation of eight known compounds, which were identified as macrosporin (1), alternariol monomethyl ether (2), alternariol (3), integric acid (4), cytochalasins D (5), C (6) and Q (7), and cyclo(D-tyrosyl-D-proline) (8). Pure isolated compounds were also evaluated for their cytotoxic effects. Compound 1 showed strongly and selectively cytotoxic activity against BT-474 and KATO-3 cell lines with IC50 values of 1.69 and 8.69 μM, respectively. Compound 2 displayed toxicity on SW- 620, KATO-3 and BT-474 cell lines (IC50: 3.01, 2.17 and 12.19 μM, respectively), while compound 3 showed selectively activity against SW-620 and CHAGO (IC50: 9.33 and 18.67 μM, respectively). Compound 4 was active to all cell lines tested. Cytochalasins Q (7) and D (5) gave the similar results and they showed to be cytotoxic against only Hep-G2, KATO-3 and BT-474 cell lines.