ABSTRACT
Objective: To study the effect of betulin derivatives combination with 5-fluorouracil or hydrazine sulfate on the ROS generation, the SOD and LDH activity using rat blood, as well as the effect of combination drugs on Ehrlich carcinoma in experiments on mice. Methods: We used a chemiluminescence technique to study the ROS generation, and spectrophotometry to determine the MDA level and the SOD and LDH activity. The model of transplanted Ehrlich ascites carcinoma was investigated on mice using a cytological analysis of ascitic fluid cells according to Pappenheim`s method. Results: In vitro experiments on rat blood at the doses of 2, 5 and 10 μg per ml revealed the dose-dependent effect of combination drugs on the antioxidant properties. In plasma, the ROS generation and the MDA level increased by 10-300% in comparison with control at the doses of 5 and 10 μg per ml only. Still, the SOD and LDH activity in general increased by 10-130% in comparison with control under the action of the studied combination drugs. The study on mice showed the effectiveness of a combination of triterpenoids and cytostatics in Ehrlich ascites carcinoma therapy. The state and behavior of the animals improved, the volume of ascites fluid decreased by 40-50% after treatment for 10 d. Conclusion: The combination of betulin derivatives with cytostatics can be used as antitumor drugs in Ehrlich ascites carcinoma therapy that is due to metabolic plasticity, increased ROS generation in enhanced antioxidant enzyme protection.
ABSTRACT
Objective: To study betulin-3,28-diphosphate (BDP) water solubility improved by forming salt complexes with hydrophilic amino alcohols: meglumine as acidosis corrector and xymedon as the water-soluble antioxidant. Methods: We used 13C-, 31P-NMR, UV-spectroscopy and potentiometric titration to study the BDP-amine salt complexes formation and their solubility using HPLC-analysis. Results: The participation of xymedon in the proton transfer reaction with BDP in aqueous solutions was confirmed by the bathochromic shift of the carbonyl band from 299.1 nm to 304.2 nm, and by a hyperchromic effect (molar extinction ε from 8508 to 10 441 l·mol-1·cm-1) in UV-spectra. BDP complexation with meglumine was estimated by UV-spectral molar ratio method at 256 nm. Molar ratio of BDP-amine complexes (1:4) was proved by 31P-NMR. The chemical shift of phosphorus at C-3 atom of BDP (δ =-0.58 ppm) changed to+3.39 ppm, and at C-28 atom (δ =+0.28 ppm)–to+4.60 ppm. BDP solubility increased 100-600 fold according to HPLC-analysis. Conclusion: BDP interaction with amine in an aqueous solution was shown to proceed via a proton transfer due to relatively weak forces such as London forces, hydrogen bonding, electrostatic and hydrophobic interactions. In general, the formation of BDP salt complexes with amines in solution determines BDP water solubility. Water-soluble BDP enables to develop hydrophilic dosage forms.