Analysis of Antioxidant, Sunscreen, and Antibacterial Activity of Three Rhizome Extracts of Curcuma as Potential Natural Ingredient Cosmetic

Rhizomes of the genus Curcuma such as C. longa, C. xanthorrhiza, and C. zedoaria are widely known in traditional medicine for their bioactive potential. Despite the widespread recognition, there is limited integrated research on antioxidant, sunscreen, and antibacterial activities for developing natural cosmetic ingredients. Therefore, this research aimed to evaluate the potency of C. longa, C. xanthorrhiza, and C. zedoaria bioactivity as well as determine the relationship between parameters. Samples of Curcuma rhizomes were extracted using a 95% ethanol solvent. An analysis was carried out to determine the extract yield, flavonoid, phenolic levels, and antioxidant activity using the DPPH and ABTS methods. In vitro sunscreen tests with SPF value parameters and antibacterial activity against P. acnes, S. aureus, and S. epidermidis were also carried out. The results showed that the highest total flavonoid levels in C. longa were 665.44 ± 6.03 mg QE/g, and phenolic were 215.47 ± 0.38 mg GAE/g. The antioxidant activity of C. longa was the strongest, with IC50 values of DPPH (58.61 ± 4.87 μg/mL) and ABTS (3.48 ± 0.37 μg/mL). The sunscreen activity test of C. longa extract at a concentration of 1,000 μg/mL showed the highest SPF value of 38.14. Regarding antibacterial activity, C. longa showed the largest inhibitory zone diameter against S. aureus and P. acnes, but C. zedoaria also has the best ability to inhibit S. epidermidis. Furthermore, a correlation analysis between variables and the Spearman test was carried out. The results showed a strong relationship between flavonoid levels, phenolics, DPPH test, and SPF value variables.