Cytotoxic activities of the dichloromethane extracts from Andrographis paniculata (Burm. f.) nees

Introduction: Although diterpenes from Andrographis paniculata Burm.f. Nees have been found to have chemotherapeutic activity, a thorough investigation on the cytotoxic and anti-proliferative analyses on different cancer cell lines using these isolated constituents has not been achieved. Objectives: The primary objective of this study was to probe the cytotoxic capacity of the labdane diterpenoids andrographolide (1), 14-deoxyandrographolide (2), 14-deoxy-12-hydroxyandrographolide (3), and neoandrographolide (4) on mutant and wild type immortalized cell lines. Methods: Breast adenocarcinoma (MCF-7), colon carcinomas (HCT-116 and HT-29), small cell lung carcinoma (H69PR), human acute monocytic leukemia (THP-1), and wild type primary normal human dermal fibroblasts - neonatal cells (HDFn) were incubated with 1-4 and the degree of cytotoxicity was analyzed by employing the in vitro PrestoBlue® cell viability assay. Working solutions of 1-4 were prepared in complete cell culture medium to a final non-toxic DMSO concentration of 0.2%. The plates were incubated at 37°C with 5% CO2 in a 98% humidified incubator throughout the assay. Nonlinear regression and statistical analyses were done to extrapolate the half maximal inhibitory concentration, IC50. One-way ANOVA (P 100 μg/mL). Conclusion: Diterpenoids 1-4 isolated from the dichloromethane extract of the leaves of A. paniculata exhibited different cytotoxic activities against MCF-7, HCT-116, HT-29, H69PR. All constituents had comparable action on HCT-116 cells but were not found to be cytotoxic to normal HDFn cells and mutant THP-1 cells.