Neurochemical Research

, Volume 32, Issue 12, pp 2103–2113 | Cite as

Curcumin Suppressed Anti-apoptotic Signals and Activated Cysteine Proteases for Apoptosis in Human Malignant Glioblastoma U87MG Cells

  • Surajit Karmakar
  • Naren L. Banik
  • Swapan K. RayEmail author
Original Paper


Glioblastoma is the most malignant human brain tumor that shows poor response to existing therapeutic agents. Search continues for an effective therapy for controlling this deadliest brain tumor. Curcumin (CCM), a polyphenolic compound from Curcuma longa, possesses anti-cancer properties in both in vitro and in vivo. In the present investigation, we evaluated the therapeutic efficacy of CCM against human malignant glioblastoma U87MG cells. Trypan blue dye exclusion test showed decreased viability of U87MG cells with increasing dose of CCM. Wright staining and ApopTag assay, respectively, showed the morphological and biochemical features of apoptosis in U87MG cells treated with 25 μM and 50 μM of CCM for 24 h. Western blotting showed activation of caspase-8, cleavage of Bid to tBid, increase in Bax:Bcl-2 ratio, and release of cytochrome c from mitochondria followed by activation of caspase-9 and caspase-3 for apoptosis. Also, CCM treatments increased cytosolic level of Smac/Diablo to suppress the inhibitor-of-apoptosis proteins and down regulated anti-apoptotic nuclear factor kappa B (NFκB), favoring the apoptosis. Increased activities of calpain and caspase-3 cleaved 270 kDa α-spectrin at specific sites generating 145 kDa spectrin break down product (SBDP) and 120 kDa SBDP, respectively, leading to apoptosis in U87MG cells. Results show that CCM is an effective therapeutic agent for suppression of anti-apoptotic factors and activation of calpain and caspase proteolytic cascades for apoptosis in human malignant glioblastoma cells.


Apoptosis Bcl-2 proteins Caspases Curcumin Glioblastoma 



This work was supported in part by the R01 grants (CA-91460 and NS-57811) from the National Institutes of Health (Bethesda, MD, USA) and by the Spinal Cord Injury Research Fund (SCIRF-0803) from the State of South Carolina to S.K.R.


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Surajit Karmakar
    • 1
  • Naren L. Banik
    • 1
  • Swapan K. Ray
    • 1
    Email author
  1. 1.Department of NeurosciencesMedical University of South CarolinaCharlestonUSA

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