Search results for "betulinic acid"
showing 10 items of 25 documents
Betulinic Acid Exerts Cytotoxic Activity Against Multidrug-Resistant Tumor Cells via Targeting Autocrine Motility Factor Receptor (AMFR).
2018
Betulinic acid (BetA) is a naturally occurring pentacyclic triterpene isolated from the outer bark of white-barked birch trees and many other medicinal plants. Here, we studied betulinic acid's cytotoxic activity against drug-resistant tumor cell lines. P-glycoprotein (MDR1/ABCB1) and BCRP (ABCG2) are known ATP-binding cassette (ABC) drug transporters that mediating MDR. ABCB5 is a close relative to ABCB1, which also mediates MDR. Constitutive activation of the EGF receptor is tightly linked to the development of chemotherapeutic resistance. BetA inhibited P-gp, BCRP, ABCB5 and mutation activated EGFR overexpressing cells with similar efficacy as their drug-sensitive parental counterparts. …
New Pharmacological Opportunities for Betulinic Acid
2017
AbstractBetulinic acid is a naturally occurring pentacyclic lupane-type triterpenoid usually isolated from birch trees, but present in many other botanical sources. It is found in different plant organs, both as a free aglycon and as glycosyl derivatives. A wide range of pharmacological activities has been described for this triterpenoid, including antiviral and antitumor effects. In addition, several other interesting properties have been identified in the fields of immunity and metabolism, namely antidiabetic, antihyperlipidemic, and anti-inflammatory activities. Taken together, these latter three properties make betulinic acid a highly interesting prospect for treating metabolic syndrome…
Betulinic acid induces a novel cell death pathway that depends on cardiolipin modification
2016
Cancer is associated with strong changes in lipid metabolism. For instance, normal cells take up fatty acids (FAs) from the circulation, while tumour cells generate their own and become dependent on de novo FA synthesis, which could provide a vulnerability to target tumour cells. Betulinic acid (BetA) is a natural compound that selectively kills tumour cells through an ill-defined mechanism that is independent of BAX and BAK, but depends on mitochondrial permeability transition-pore opening. Here we unravel this pathway and show that BetA inhibits the activity of steroyl-CoA-desaturase (SCD-1). This enzyme is overexpressed in tumour cells and critically important for cells that utilize de n…
Estrogen Receptor Signaling and the PI3K/Akt Pathway Are Involved in Betulinic Acid-Induced eNOS Activation
2016
Betulinic acid (BA) is a naturally occurring pentacyclic triterpenoid with anti-inflammatory, antiviral and anti-cancer properties. Beneficial cardiovascular effects such as increased nitric oxide (NO) production through enhancement of endothelial NO synthase (eNOS) activity and upregulation of eNOS expression have been demonstrated for this compound. In the present study, immortalized human EA.hy 926 endothelial cells were incubated for up to 1 h with 1–100 µM BA and with the phosphatidylinositol-3-kinase (PI3K) inhibitors LY294002 and wortmannin, or the estrogen receptor (ER) antagonist ICI 182,780. Phosphorylation status of eNOS and total eNOS protein were analyzed by Western blotting us…
Pharmacological research on natural substances in Latvia: Focus on lunasin, betulin, polyprenol and phlorizin
2016
In this concise review the current research in plant bioactive compound studies in Latvia is described. The paper summarizes recent studies on substances from edible plants (e.g., cereals and apples) or their synthetic analogues, such as peptide lunasin, as well as substances isolated from inedible plants (e.g., birch and conifer), such as pentacyclic triterpenes (e.g., betulin, betulinic acid, and lupeol) and polyprenols. Latvian researchers have been first to demonstrate the presence of lunasin in triticale and oats. Additionally, the impact of genotype on the levels of lunasin in cereals was shown. Pharmacological studies have revealed effects of lunasin and synthetic triterpenes on the …
Betulinic Acid Kills Colon Cancer Stem Cells
2016
Cancer stem cells (CSCs) are considered to be the origin of cancer and it is suggested that they are resistant to chemotherapy. Current therapies fail to eradicate CSCs and therefore selecting a resistant cell subset that is able to facilitate tumor recurrences. Betulinic acid (BetA) is a broad acting natural compound, shown to induce cell death via the inhibition of the stearoyl-CoA- desaturase (SCD- 1). This enzyme converts saturated fatty acids into unsaturated fatty acids and is over-expressed in tumor cells. Here we show that BetA induces rapid cell death in all colon CSCs tested and is able to affect the CSCs directly as shown, via the loss of clonogenic capacity. Similar results were…
Triterpene saponins from the roots ofAmpelozizyphus amazonicus
1992
A new triterpene saponin was isolated from the roots of Ampelozizyphus amazonicus together with the known 3-O-beta-D-glucopyranosyl-20-O-alpha-L-rhamnopyranosyljujubogenin and the known triterpenes melaleucic acid, 3 beta,27 alpha-dihydroxylup-20(29)-en-28 beta-oic acid, betulinic acid, betulin, lupeol. The structure of this saponin was elucidated as 3-O-[beta-D-glucopyranosyl(1----2)alpha-L-arabinopyranosyl]- 20-O-alpha-L-rhamnopyranosyljujubogenin by spectral analysis and chemical transformations.
Effect of selected triterpenoids on chronic dermal inflammation.
1997
The activity of four natural triterpenoids on a 12-O-tetradecanoylphorbol-13-acetate multiple-dose model of skin chronic inflammation was studied. Erythrodiol and ursolic acid were significantly effective. The most important features concerning structure-activity relationship and previous data on the effect of these triterpenoids on other inflammatory conditions are discussed.
Betulin binds to melanocortin receptors and antagonizes alpha-melanocyte stimulating hormone induced cAMP generation in mouse melanoma cells.
2007
Betulin is a principal component of birch bark and is known to possess a broad range of biological activities, including antiinflammatory, antiviral and anticancer actions. The present study was carried out in vitro to clarify the influence of betulin on melanocortin (MC) receptor-ergic signalling by using COS-7 cells transfected with corresponding human MC receptor DNA. The results showed that betulin binds to the human melanocortin MC1, three to five receptors with selectivity to the MC1 subtype (K(i) value 1.022 +/- 0.115 microM). Betulin binds to the MC receptors with the following potency order-MC > MC3 > MC5 > MC4. Betulin itself does not stimulate cAMP generation, however, it slightl…
Selected Secondary Plant Metabolites for Cancer Therapy
2015
Secondary plant metabolites reveal numerous biological activities making them attractive as resource for drug development of human diseases. As the majority of cancer drugs clinically established during the past half century is derived from nature, cancer researchers worldwide try to identify novel natural products as lead compounds for cancer therapy. Natural products are considered as promising cancer therapeutics, either as single agents or in combination protocols, to enhance the antitumor activity of additional therapeutic modalities. Most natural compounds exert pleotrophic effects and modulate various signal transduction pathways. A better understanding of the complex mechanisms of a…