Topical Area: Dietary Bioactive Components
Human antigen R (HuR) is a homolog of Drosophila embryonic lethal abnormal vision (ELAV1). HuR binds to, stabilizes cytokine mRNAs, and plays an important role in tumorigenesis and inflammation. Plant extracts and compounds that can regulate HuR gene expression may have nutritional and therapeutic value, but no prior research was done. The objective of this study was to evaluate the effect of cottonseed extracts, anti-nutritional gossypol and endotoxin lipopolysaccharides (LPS) on the regulation of HuR gene expression in mouse macrophages.
Methods : Mouse RAW264.7 macrophages were treated with multiple concentrations of glanded and glandless cottonseed extracts, gossypol and LPS for 2, 8 and 24 h. qPCR and immunoblotting were used to detect the expression of HuR mRNA and protein.
qPCR assay showed that cottonseed extracts and LPS had minimal effect on HuR gene expression. However, gossypol increased HuR mRNA levels up to 16-fold in cells treated for 24 h. Immunoblotting confirmed that gossypol also increased HuR protein in macrophages.
These results show for the first time that gossypol is a strong stimulator of HuR gene expression and that cottonseed extracts essentially free of gossypol are probably safe to use as a reliable source of plant polyphenols.
Funding Sources : This work was supported by the USDA-ARS Quality and Utilization of Agricultural Products National Program 306 through CRIS 6054-41000-103-00-D. USDA is an equal opportunity provider and employer.