Synthesis, Characterization, and Bioactivity of Nanocurcumin: Antioxidant and Antibacterial Properties

Curcumin is found naturally in a natural turmeric herb (Curcuma longa), and it is known to be a non-toxic bioactive compound. It has been recognized for centuries as a household remedy for various health-related conditions. In this study, sun-dried Turmeric rhizomes are ground and used to extract nanocurcumin via the Soxhlet extraction method, using ethanol as solvent. This study aims to decrease the size of nanocurcumin to enhance its bioavailability. The upsurge in bioavailability tends to increase antioxidant and antimicrobial activity. The size of the synthesized nanocurcumin nanoparticles was between 62 and 75 nm. Notably, the chemical structure of Nanocurcumin remained unchanged from natural curcumin while using ethanol as the solvent, with no modifications during nanoparticle preparation. All of the peaks in the nanocurcumin FTIR and XRD spectra are separated and correspond to those of curcumin. Results demonstrated that nanocurcumin exhibited a significant antioxidant potential with 92% of nitric oxide (NO) scavenging activity and a remarkable 98% of hydrogen peroxide (H2O2) scavenging activity. Moreover, the nanoparticles have high inhibitory concentration against bacterial strains. The antibacterial assay performed in vitro confirms the antibacterial activity of the synthesized Nanocurcumin against both Gram-positive and Gram-negative bacteria, with larger inhibition zones of 3.8 ± 0.12 cm for E. coli and 3.1 ± 0.13 cm for S. aureus. These findings demonstrate that reducing curcumin to the nano range via Soxhlet-extracted nanocurcumin is a promising candidate for antioxidant and antibacterial applications.