This report describes the effect of triacontanol on shoot multiplication and production of antioxidant compounds (carnosic acid, carnosol and rosmarinic acid) in S. officinalis cultures grown on MS basal medium (agar solidified medium supplemented with 0.1 mg l-1 IAA, 0.45 mg l-1 BAP). It was found that shoot proliferation significantly increased when triacontanol at concentrations of 5, 10 or 20 µg l-1 was added to the medium. HPLC analysis of acetone and methanolic extracts of sage shoots showed that the production of diterpenoids, carnosic acid/carnosol ratio, as well as, contents of rosmarinic acid were also affected by the treatment with triacontanol. The highest stimulation effect of triacontanol was observed on the production of carnosol, where the treatment with 20 µg l l-1 increased the content of this diterpenoid 4.5-fold compared to that in the control (sage shoots growing on MS basal medium, only).
A series of new benzimidazole derivatives were synthesized and tested in vitro for possible anticancer activity. Their effect of proliferation into selected tumor cell lines at normoxia and hypoxia conditions was determined by WST-1 test. Additionally, apoptosis test (caspase 3/7 assay) was used to check the mode caused by the agents of cell death. Four of the examined compounds (7, 8, 13, 11) showed a very good antiproliferative effect and three of them were specific for hypoxia conditions (8, 14, 11). Compound 8 was the most cytotoxic against human lung adenocarcinoma A549 cells at hypoxic conditions. Hypoxia/ normoxia cytotoxic coefficient of compound 14 (4.75) is close to hypoxia/normoxia cytotoxic coefficient of tirapazamine (5.59) - a reference compound in our experiments and this parameter locates it between mitomycin C and 2-nitroimidazole (misonidazole). Screening test of caspase-dependent apoptosis proved that exposure to A549 cells of compounds 7-8 and 13-14 for 48 h promote apoptotic cell death. These results supplement our earlier study of the activity of new potentialy cytotoxic heterocyclic compounds against selected tumor cells.
The concentrations of carnosic acid, carnosol and rosmarinic acid in different materials from differentiated (multiple shoot cultures and regenerated plants) and undifferentiated (callus and cell suspension) in vitro cultures of Salvia officinalis were determined by HPLC. The results suggested that diterpenoid (carnosic acid and carnosol) production is closely related to shoot differentiation. The highest diterpenoid yield (11.4 mg g-1 for carnosic acid and 1.1 mg g-1 for carnosol) was achieved in shoots of 10-week-old micropropagated plants. The levels were comparable to those found in shoots of naturally growing plants. Undifferentiated callus and cell suspension cultures produced only very low amounts of carnosol (ca. 0.05 mg g-1 of dry weight). In contrast, content of rosmarinic acid in callus and suspension cultures as well as shoots growing in vitro and in vivo was similar and ranged between 11.2 and 18.6 mg g-1 of dry weight.
Obtained benzimidazole derivatives, our next synthesized heterocyclic compounds, belong to a new group of chemical bondings with potential anticancer properties (Błaszczak-Świątkiewicz & Mikiciuk-Olasik, 2006, J Liguid Chrom Rel Tech 29: 2367-2385; Błaszczak-Świątkiewicz & Mikiciuk-Olasik, 2008, Wiad Chem 62: 11-12, in Polish; Błaszczak-Świątkiewicz & Mikiciuk-Olasik, 2011, J Liguid Chrom Rel Tech 34: 1901-1912). We used HPLC analysis to determine stability of these compounds in 0.2% DMSO (dimethyl sulfoxide). Optimisation of the chromatographic system and validation of the established analytical method were performed. Reversed phases (RP-18) and a 1:1 mixture of acetate buffer (pH 4.5) and acetonitrile as a mobile phase were used for all the analysed compounds at a flow rate 1.0 mL/min. The eluted compounds were monitored using a UV detector, the wavelength was specific for compounds 6 and 9 and compounds 7 and 10. The retention time was specific for all four compounds. The used method was found to have linearity in the concentration range of (0.1 mg/mL-0.1 μg/mL) with a correlation coefficient not less than r2=0.9995. Statistical validation of the method proved it to be a simple, highly precise and accurate way to determine the stability of benzimidazole derivatives in 0.2% DMSO. The recoveries of all four compounds examined were in the range 99.24-100.00%. The developed HPLC analysis revealed that the compounds studied remain homogeneous in 0.2% DMSO for up to 96 h and that the analysed N-oxide benzimidazole derivatives do not disintegrate into their analogues - benzimidazole derivatives. Compounds 8, 6 and 9 exhibit the best cytotoxic properties under normoxic conditions when tested against cells of human malignant melanoma WM 115.