In vitro bioactivities and preparation of nanoemulsion from coconut oil loaded Curcuma aromatica extracts for cosmeceutical delivery systems

Curcuma aromatica (CA) is a herbaceous plant in the Zingiberaceae family. It has antioxidative activity and anti-inflammatory properties. The purpose of this study was to investigate the effect of solvents and extraction methods on CA rhizomes. The crude extracts were tested for phenolic and flavonoid contents, antioxidative activity by DPPH and lipid peroxidation assay, and protein denaturation inhibition. The crude extracts with 95% ethanol by maceration technique showed good results. It had phenolic content at 99.28 ± 1.09 mg GAE/g extract, flavonoid content at 397.00 ± 27.54 mg QE/g extract, antioxidative activity by DPPH assay and lipid peroxidation assay at IC₅₀ value of 0.55 ± 0.02 mg/ml and 0.60 ± 0.10 mg/ml, respectively. The percentage of protein denaturation inhibition was 65.97 ± 4.68%. The crude extract with 95% ethanol by maceration technique was selected to formulate nanoemulsion. Nanoemulsion formulation consisted of DI water, Tween 80, CA extract, coconut oil and Span 80 at 72.50, 12.93, 7.07, 5.00 and 2.5%w/w, respectively. Its appearance was an opaque yellow liquid with no precipitation and no phase separation at room temperature. The particle size, pH, and viscosity were 70.20 ± 0.38 nm, 5.87 ± 0.01 and 3.56 ± 0.24 cP, respectively. Nanoemulsion loaded CA extract had bioactivities and highly stable characteristics after heating–cooling test for 6 cycles. This study has demonstrated the potential of nanoemulsion from coconut oil loaded CA extract for further development to novel cosmetic products.