Gynura bicolor is a medicinal plant recognized for its antioxidant potential and natural pigments. This study aimed to evaluate antioxidant activities and bioactive compounds’ contents of G. bicolor extracts and solvent fractions prepared using different drying methods and solvent partitioning. Ethanol extracts were obtained from freeze-dried (FD) and hot-air-dried (HD) samples, followed by sequential partitioning with n-hexane (n-Hex), methylene chloride (MC), ethyl acetate (EA), and n-butanol (n-BuOH). Total polyphenol (TP) and flavonoid (TF) contents were measured. Antioxidant activities were assessed via DPPH and ABTS radical scavenging assays. The FD-EtOH extract showed the highest TP (100.8±0.29 mg TAE/mL) and TF (4.72±0.03 mg QE/mL) contents. EA and n-BuOH fractions exhibited significantly higher antioxidant activity than other fractions, suggesting that bioactive compounds were effectively concentrated through selective solvent extraction. These findings indicate that drying and solvent fractionation can significantly affect antioxidant functionality and phytochemical yield. G. bicolor may serve as a promising natural antioxidant and pigment source for functional food and beverage development.

Oxidative stress caused by reactive oxygen species (ROS) is a key mechanism of skin aging, and the use of antioxidants is an effective strategy to prevent the symptoms associated with ROS-induced skin aging. The components rich in polyphenolic compounds with antioxidative activity were identified by fractionating an aqueous ethanolic extract of Gryllus bimaculatus (AE-GBE) using solvent using hexane, chloroform, ethyl acetate, butanol, and water. Their ability to migrate H2O2-induced oxidative stress in human dermal fibroblasts (HDFs) was then evaluated. The butanol fraction of AE-GBE had the highest polyphenol content and antioxidant effect, followed by the ethyl acetate and water fractions, suggesting that the likely antioxidant components are polar components. Furthermore, the butanol, ethyl acetate, and water fractions effectively reduced intracellular ROS production and DNA damage in HDF cells caused by H2O2. Overall, these findings suggest that the butanol fraction of AE-GBE shows promise as a natural insect-derived antioxidant material, capable of suppressing oxidative stress by showing a stronger antioxidant effect under H2O2 stimulation than the other fractions.