Affiliations: Department of Animal & Dairy Science,
University of Georgia, Athens, GA, USA | Department of Foods and Nutrition, University of
Georgia, Athens, GA, USA
Note: [] Address for correspondence: Clifton A. Baile, 444 Edgar L.
Rhodes Center for Animal and Dairy Science, University of Georgia, Athens, GA
30602-2771, USA. Tel.: +1 706 542 2771; Fax: +1 706 542 7925; E-mail:
cbaile@uga.edu
Abstract: Withaferin A (WA), a highly oxygenated steroidal lactone that is
found in the medicinal plant Withania somnifera (also called ashwagandha)
has been reported to have anti-tumor, anti-angiogenesis, and pro-apoptotic
activity. We investigated the effects of WA on viability, apoptosis and
adipogenesis in 3T3-L1 adipocytes. Pre- and post-confluent preadipocytes and
mature adipocytes were treated with WA (1–25 μM) up to
24~hrs. Viability and apoptosis were measured by
CellTiter-Blue® Cell Viability Assay and
single strand DNA ELISA Assay, respectively. WA decreased viability and induced
apoptosis in all stages of cells. Induction of apoptosis by WA in mature
adipocytes was mediated by increased ERK1/2 phosphorylation and altered Bax and
Bcl2 protein expression. The effect of WA on adipogenesis was examined by
AdipoRed™ Assay after treating with WA
(0.1–1 μM) during the differentiation period. WA
decreased lipid accumulation in a dose-dependent manner and decreased the
expression of peroxisome proliferator-activated receptor
γ, CCAAT/enhancer binding protein
α and adipocyte fatty acid binding protein. The effects
on apoptosis and lipid accumulation were also confirmed with Hoechst staining
and Oil Red O staining, respectively. These results show that WA acts on
adipocytes to reduce cell viability and adipogenesis and also induce
apoptosis.
