Evaluating the cytotoxic effects of the treated leaves of Dracocephalum moldavica (L.) using different elicitors on four human cancer cell lines

Since products extracting from medicinal plants play an important role in the treatment of cancer, this study was performed to investigate the cytotoxicity effects of the total extracts obtained from the leaves of Dracocephalum moldavica (L.) treated with different elicitors on four human cancer cell lines.

Following cultivating the Dracocephalum moldavica in Kerman for two years, foliar spraying was carried out using salicylic acid and beta-aminobutyric acid at 0, 0.5 and 1 mM concentrations one month before harvesting. Then, the cytotoxic effect of each extract at two concentrations; 0.25 and 0.125 mg/ml was evaluated towards four human cancer cell lines at 5 replications using MTT assay. 3-5 × 103 number of the cells were seeded in 96-well plates and the percentage of cytotoxicity was determined after 72 h of incubation.

Among the four cancer cell lines, liver and breast cancer cells demonstrated the most sensitivity against the total extracts obtaining from the treated leaves of D.moldavica depending on the type treatment with different amounts of salicylic acid and beta-aminobutyric acid elicitors at two concentrations; 0.25 and 0.125 mg/ml after 72 hours of incubation. Results also showed that the lowest sensitivity to the extracts belonged to the colorectal carcinoma cells at two concentrations. Usage of both salicylic acid and beta-aminobutyric acid as elicitors in the process of plant growth increased the percentage of cytotoxicity on Hep-G2 cell line, while it had no remarkable effect on HT-29 cells.

Total extracts obtaining from the treated leaves of D. moldavica at a high concentration displayed a considerable cytotoxicity towards human breast and hepatocellular carcinomas. Indeed, further studies are needed to separate the constituents of the extracts and investigate their effects.