Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression
Yuan WQ, Zhang RR, Wang J and others. Oncotarget, May 2016.
Read the paper Free to read · doi:10.18632/oncotarget.8965
What this paper is about
Cancer cells resist chemotherapy partly by pumping the drug back out with P-glycoprotein. This study isolated a new steroidal glycoside from tropical milkweed that reduces how much of that pump the cell makes.
Resistant breast and liver cancer cell lines became responsive to paclitaxel and doxorubicin again when the compound was added.
Summarised here from the abstract below. Not the authors’ words.
Abstract
Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants.
Abstract reproduced from the published paper, which is licensed CC BY. Copyright remains with the authors.
Key terms
Milkweeds in this paper
- Tropical Milkweed Asclepias curassavica
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"Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression (listing)." Milkweed USA, 2026, https://milkweedusa.com/research/asclepiasterol-a-novel-c21-steroidal-glycoside-derived-from-asclepias-2016/. Accessed DATE.
Milkweed USA. "Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression (listing)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/research/asclepiasterol-a-novel-c21-steroidal-glycoside-derived-from-asclepias-2016/.
@misc{milkweedusa_researchasclepiasterolanovel,
title = {Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression (listing)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/research/asclepiasterol-a-novel-c21-steroidal-glycoside-derived-from-asclepias-2016/},
note = {Accessed DATE}
}