Curcumin, an ingredient of turmeric, exhibits a variety of
biological activities such as anti-inflammatory, anti-atherosclerotic, anti-proliferative,
anti-oxidant, anti-
cancer and anti-metastatic. It is a highly pleiotropic molecule that inhibits cell proliferation and induces apoptosis in
cancer cells. Despite its imperative
biological activities, chemical instability, photo-instability and poor bioavailability limits its utilization as an effective therapeutic agent. Therefore, enhancing the bioavailability of
curcumin may improve its therapeutic index for clinical setting. In the present study, we have conjugated
curcumin with a biodegradable
polymer Poly (D, L-lactic-co-glycolic acid) and evaluated its apoptotic potential in human colon
carcinoma cells (HCT 116). The results show that
curcumin-PLGA conjugate efficiently inhibits cell proliferation and cell survival in human colon
carcinoma cells as compared to native
curcumin. Additionally,
curcumin conjugated with PLGA shows improved cellular uptake and exhibits controlled release at physiological pH as compared to native
curcumin. The
curcumin-PLGA conjugate efficiently activates the cascade of
caspases and promotes intrinsic apoptotic signaling. Thus, the results suggest that conjugation potentiates the sustainability, anti-proliferative and apoptotic activity of
curcumin. This approach could be a promising strategy to improve the therapeutic index of
cancer therapy.