Turmeric (Curcuma longa) has been shown to possess anti-inflammatory, antioxidant and antitumor properties.
Extraction, partition and column chromatography of the dry powder of C. longa rhizomes showed presence of biological
activity only in ethyl acetate eluted fraction in clonogenic assays using highly metastatic PC-3M prostate cancer cell line.
HPLC, UV-Vis and Mass spectra studies showed presence of three curcuminoids in this fraction. Accordingly, we have
made an attempt to identify the proteins modulated by purified turmeric fraction in PC-3M human prostate cancer cell line
using high-resolution two-dimensional gel electrophoresis (2-DE). Isoelectric focusing and 2-DE analysis showed a total
of 29 proteins altered by treatment with ethyl acetate fraction (EAF) of C. longa. Out of 29 differentially expressed proteins,
15 were identified by peptide mass fingerprinting through LC/MS/MS sequencing. From these, a total of 7 were
down-regulated and 8 were up-regulated spots. The down-regulated proteins identified by Peptide Mass Fingerprinting are
Elongation Factor 2 (eEF2), Stress-induced phosphoprotein 1, Glutathione S-transferase (GST) Omega-1, Parvalbumin
alpha, Succinyl-CoA: ketoacid, Lamin-A/C and Annexin A2. The up-regulated proteins identified by Peptide Mass Fingerprinting
include 78 kDa Glucose-regulated protein precursor (GRP78), Protein disulfide isomerase (PDI) precursor,
Actin cytoplasmic 2, protein SET, Calreticulin precursor, Nucleophosmin, Vimentin, and Aortic alpha-actin (ACTA2).
The identified proteins have diverse cellular functions such as ER stress, Unfolded Protein Response (UPR), cytoskeletal,
structural, regulatory, and apoptotic proteins that will require further in-depth studies to understand the biological significance.