Antiproliferative and Cytotoxic Properties of Propynoyl Betulin Derivatives against Human Ovarian Cancer Cells: In Vitro Studies

Due to the incidence of ovarian cancer (OC) and the limitations of available therapeutic strategies, it is necessary to search for novel therapeutic solutions. The aim of this study was to evaluate the cytotoxic effect of betulin 1 and its propynoyl derivatives 2–6 against ovarian cancer cells (SK-OV-3, OVCAR-3) and normal myofibroblasts (18Co). Paclitaxel was used as the reference compound. The propynoyl derivatives 2–6 exhibited stronger antiproliferative and cytotoxic activities compared to betulin 1. In both ovarian cancer cell lines, the most potent compound was 28-propynoylbetulin 2. In the case of compound 2, the calculated IC50 values were 0.2 µM for the SK-OV-3 cells and 0.19 µM for the OVCAR-3 cells. Under the same culture conditions, the calculated IC50 values for compound 6 were 0.26 µM and 0.59 µM, respectively. It was observed that cells treated with compounds 2 and 6 caused a decrease in the potential of the mitochondrial membrane and a significant change in cell morphology. Betulin 1, a diol from the group of pentacyclic triterpenes, has a confirmed wide spectrum of biological effects, including a significant anticancer effect. It is characterized by low bioavailability, which can be improved by introducing changes to its structure. The results showed that chemical modifications of betulin 1 only at position C-28 with the propynoyl group (compound 2) and additionally at position C-3 with the phosphate group (compound 3) or at C-29 with the phosphonate group (compound 6) allowed us to obtain compounds with greater cytotoxic activity than their parent compounds, which could be used to develop novel therapeutic systems effective in the treatment of ovarian cancer

Anticancer Activity of the Acetylenic Derivative of Betulin Phosphate Involves Induction of Necrotic-Like Death in Breast Cancer Cells In Vitro

Betulin (BT) is a natural pentacyclic lupane-type triterpene exhibiting anticancer activity. Betulin derivatives bearing propynoyloxy and phosphate groups were prepared in an effort to improve the availability and efficacy of the drug. In this study, a comparative assessment of the in vitro anticancer activity of betulin and its four derivatives was carried out using two human breast cancer cell lines: SK-BR-3 and MCF-7. In both studied cell lines, 30-diethoxyphosphoryl-28-propynoylbetulin (compound 4) turned out to be the most powerful inhibitor of growth and inducer of cellular death. Detailed examination of that derivative pertained to the mechanisms underlying its anticancer action. Treatment with compound 4 decreased DNA synthesis and up-regulated p21WAF1/Cip1 mRNA and protein levels in both cell lines. On the other hand, that derivative caused a significant increase in cell death, as evidenced by increased lactate dehydrogenase (LDH) release and ethidium homodimer uptake. Shortly after the compound addition, an increased generation of reactive oxygen species and loss of mitochondrial membrane potential were detected. The activation of caspase-3 and fragmentation of genomic DNA suggested an apoptotic type of cell death. However, analysis of cellular morphology did not reveal any nuclear features typical of apoptosis. Despite necrosis-like morphology, dead cells exhibited activation of the cascade of caspases. These observations have led to the conclusion that compound 4 pushed cells to undergo a form of necrotic-like regulated cell demise

Anticancer Activity of the Acetylenic Derivative of Betulin Phosphate Involves Induction of Necrotic-Like Death in Breast Cancer Cells In Vitro

Betulin (BT) is a natural pentacyclic lupane-type triterpene exhibiting anticancer activity. Betulin derivatives bearing propynoyloxy and phosphate groups were prepared in an effort to improve the availability and efficacy of the drug. In this study, a comparative assessment of the in vitro anticancer activity of betulin and its four derivatives was carried out using two human breast cancer cell lines: SK-BR-3 and MCF-7. In both studied cell lines, 30-diethoxyphosphoryl-28-propynoylbetulin (compound 4) turned out to be the most powerful inhibitor of growth and inducer of cellular death. Detailed examination of that derivative pertained to the mechanisms underlying its anticancer action. Treatment with compound 4 decreased DNA synthesis and up-regulated p21WAF1/Cip1 mRNA and protein levels in both cell lines. On the other hand, that derivative caused a significant increase in cell death, as evidenced by increased lactate dehydrogenase (LDH) release and ethidium homodimer uptake. Shortly after the compound addition, an increased generation of reactive oxygen species and loss of mitochondrial membrane potential were detected. The activation of caspase-3 and fragmentation of genomic DNA suggested an apoptotic type of cell death. However, analysis of cellular morphology did not reveal any nuclear features typical of apoptosis. Despite necrosis-like morphology, dead cells exhibited activation of the cascade of caspases. These observations have led to the conclusion that compound 4 pushed cells to undergo a form of necrotic-like regulated cell demise

Bioresorbable filomicelles for targeted delivery of betulin derivative – In vitro study

International audienceFilomicelles (worm-like micelles) possess high drug loading capacity and long circulation time in the bloodstream. A novel approach can be filomicelles with folic acid (FA) as a targeting moiety. Folate-drug delivery systems can target FA receptors (FAR) that are overexpressed in several human carcinomas, which can potentially maximize therapeutic efficacy while minimizing side effects. The aim of this study was to develop filomicelles from combination of poly(L-lactide)-Jeffamine-folic acid and poly(L-lactide)-poly(ethylene glycol) for delivery of betulin derivative. Phosphate derivative of betulin reveals high cytotoxicity against cancer cells, however its application is restricted due to poor solubility in water. Incorporation into hydrophobic core of micelles can effectively solubilize the drug. Three kinds of micelles were obtained with high drug loading capacity. Based on TEM analysis, the copolymers formed exclusively filomicelles or mixture of filomicelles and spherical micelles. All kinds of micelles provided release of betulin derivative for over 9 days and apart the very initial phase displayed similar release profile. The influence of PLA block on initial burst effect was revealed. The in vitro cytotoxicity of betulin derivative loaded micelles against FAR-positive HeLa cells was confirmed, which proves their usefulness for targeted delivery of cytostatic drug