A new and relatively simple method for purification of betulin from birch bark extract was developed in this study. Its five purification steps are based on the differential solubility of extract components in various solvents and their crystallization and/or precipitation, on their affinity for Ca(OH)2 in ethanol, and on the affinity of some impurities for silica gel in chloroform. In addition, all used solvents can be simply recycled. Betulin of more than 99% purity can be prepared by this method with minimal costs. Various observations including crystallization of betulin, changes in crystals during heating, and attempt of localization of betulin in outer birch bark are also described in this work. The original extract, fraction without betulinic acid and lupeol, amorphous fraction of pure betulin, final crystalline fraction of pure betulin and commercial betulin as a standard were employed to determine the antiproliferative/cytotoxic effect. We used WST-1 tetrazolium-based assays with triple negative breast cancer cell line BT-549. The decrease in cell survival showed clear relationship with the purity of the samples, being most pronounced using our final product of pure crystalline betulin. WST-1 proliferation/cytotoxicity test using triple negative breast cancer cell line BT-549 clearly showed the importance of purity of betulin for biological experiments and, apparently, for its medicinal use.

It is documented that deficient fucosylation may play an important role in the pathogenesis of cancer. Since the supplementation ofL-fucosecouldrestorefucosylationinbothin vitro and in vivoconditions,ourintentwastoexaminetheeffectofintraperitoneal administration of L-fucose and L-rhamnose (a similar deoxysaccharide) on tumour growth, mitotic activity and metastatic setting ofasolidformofEhrlichcarcinomaaswellasonthesurvivalrateoftumourbearingmice.BothL-fucoseandL-rhamnoseexerted a significant suppressive effect on tumour growth (P<0.05). After 10 days of therapy, the greatest inhibition of tumour growth expressedasapercentageofcontrolswasobservedinL-rhamnoseatadoseof3g/kg/day(by62%)andL-fucoseatadoseof 5g/kg/day(by47%).Moreover,themitoticindexdecreasedwithincreasingdosesofL-fucoseandL-rhamnose.Prolongedsurvivalof tumourbearingmicewasobservedafter14consecutivedaysofdailyadministeringL-rhamnose.Itsoptimaldosewasestimatedto be3.64g/kg/day.L-Fucose,however,displayedonlyaslighteffectonthesurvivalofthemice.OurresultssuggestthatL-fucoseand especiallyL-rhamnosehaveanticancerpotential.Thisstudyisthefirsttodemonstratethetumour-inhibitoryeffectofL-rhamnose.

Aim. To evaluate the anticancer effect of alpha-tomatine (i.p.) either alone or in combination with doxorubicin (i.v.) in a mouse tumour model. Methods. We studied the effect of repeated alpha-tomatine (0.1 -9 mg/kg) and/or doxorubicin (2 mg/kg) on the growth and mitotic activity of the solid Ehrlich tumour in vivo, as well as on the survival of the tumour-bearing mice. Results. Monotherapy with alpha-tomatine had a significant dose-dependent anticancer effect which peaked at 1 mg/kg. This was shown by both slowed tumour growth and reduced tumour cell proliferation. We also provide the first evidence that the combination alpha-tomatine (1 mg/kg) and doxorubicin (2 mg/kg) had a synergistic effect and significantly prolonged the survival of the mice. Neither alpha-tomatine nor doxorubicin influenced the infiltration of tumours with CD3+ lymphocytes; nor were we able to find an in vivo modulation of the key molecules of two regulatory pathways reported in vitro as the principal anti-cancer mechanisms of alpha-tomatine, i.e. iNOS and phosphorylated ERK2. However, alpha-tomatine still led to intracellular DNA inhibition and protein synthesis in Ehrlich tumour cells in a short-term culture ex vivo with IC 50 values of 8.7 and 6.6 µM. Conclusions.The results suggest that ΤΟΜ, especially in combination with doxorubicin, may be a promising agent for the treatment of malignant solid tumours. Despite growing knowledge of the mechanisms of ΤΟΜ action in cancer cells, most aspects remain unclear. Parallel organ toxicity, especially potential liver effects, requires careful attention when performing in vivo studies in the future.

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The present study is the first to describe in detail pharmacokinetic parameters and the biliary excretion of melibiose and rhamnose in healthy and cholestatic rats. The altered melibiose/rhamnose biliary excretion ratio in BDO rats indicates that the test is able to detect the impairment of the blood-biliary barrier in acute extrahepatic cholestasis.