Cytotoxic activity screening of 19 Bangladeshi medicinal plants against healthy mouse fibroblast (NIH3T3), healthy monkey kidney (VERO), gastric cancer (AGS), colon cancer (HT-29), breast cancer (oestrogen-dependent, MCF-7; non-oestrogen-dependent, MDA-MB-231) cells are reported here for the first time to confirm the traditional use of some plants as anticancer agents and to additionally identify new plants with significant anticancer potential.
Extraction of plant materials The shade-dried, powered plant materials were extracted by soaking in methanol for 24 h. The extracts were then filtered and the solvent evaporated (rotary evaporator), followed by freeze drying.
Phytochemical profile The phytochemical profiles of the plant extracts were obtained by analytical HPLC (Luna C18, 250 9 4.6 mm column) using 10–90 % methanol in water as the mobile phase with UV detection at 210 and 280 nm (see supplementary data).
Cell culture Two normal cell lines, namely mouse fibroblast (NIH3T3, ATCC CRL-1658) and healthy monkey kidney cells (VERO, ATCC CCL-81), and four human cancer cell lines, namely gastric (AGS, ATCC CRL-1739), colon (HT-29, ATCC HTB-38), non-oestrogen-dependent breast (MDAMB-231, ATCC HTB-26) and oestrogen-dependent breast (MCF-7, ATCC: HTB-22) cancer cells, were used for cytotoxicity screening of the selected Bangladeshi medicinal plant extracts. All cell lines were purchased from ATCC, Manassas, VA 20108, USA. Cell lines were cultured in Advanced DMEM supplemented with 10 % inactivated NBCS and 5 mM L-glutamine, and grown at 37 C in a humidified atmosphere of 5 % CO2 in air.
MTT colorimetric assay The MTT colorimetric assay was performed to evaluate the cytotoxicity of the selected Bangladeshi plant extracts according to the method described and validated by Uddin et al. [8]. Briefly, the cells were seeded in 96-well plates at a density of 1.0 9 104 –2.0 9 104 cells/well. Following 24 h incubation and attachment, the cells were treated with different concentrations of plant extract for 48 h. Washing and incubation with MTT solution for 2 h was followed by cells being lysed with dimethyl sulfoxide (DMSO). The absorbance was measured after 45 min using a microplate reader (Wallac 1420 Multilabel counter, PerkinElmer) at a wavelength of 560 nm. DMSO (2 %), was used to dissolve the extracts. It showed less than 20 % cell growth inhibition and served as the negative control, whereas 20 % DMSO ([80 % cell growth inhibition) and cycloheximide served as positive controls. The results are generated from two independent experiments; each experiment was performed in triplicate. The IC50 values were calculated with Probit analysis software (LdP Line software, USA).