Enhanced Antioxidant and Cytotoxic Potential of Nanocurcumin: Extraction, Characterization, and Comparative Bioactivity Evaluation

Abstract

Curcumin, the major bioactive component of Curcuma longa, has wide-ranging pharmacological properties, such as anti-inflammatory, antioxidant, and anticancer effects. Its therapeutic potential is, however, hampered by poor aqueous solubility and poor systemic bioavailability. Nanocurcumin formulations provide a means of bypassing these constraints through enhanced solubility, absorption, and biological activity. In the present study, curcumin was isolated from C. longa rhizomes using Soxhlet extraction, column chromatography-purified, and characterized by thin-layer chromatography. Nanocurcumin was prepared by a top-down ultrasonication method with nanoparticles with a mean size of about 200 nm. UV–Visible spectroscopy characterization showed a significant blue shift (from 475 nm in bulk curcumin to 434 nm in nanocurcumin), indicating size-dependent optical behavior. Fourier transform infrared spectroscopy (FTIR) established structural integrity, whereas scanning electron microscopy (SEM) and X-ray diffraction (XRD) established nanoscale particle size and partial amorphization. Antioxidant activity, as defined by the Ferric Reduction Antioxidant Potential (FRAP) assay, showed enhanced radical scavenging capability of nanocurcumin compared to bulk curcumin. In vitro cytotoxicity in Dalton's lymphoma ascites (DLA) cells showed enhanced cell death with treatment with nanocurcumin, commensurate with enhanced bioavailability. Together, these data nominate nanocurcumin as a promising candidate for therapeutic development, meriting further in vivo and mechanistic studies.