Nanoparticle Encapsulation of the Hexane Fraction of Cyperus Rotundus Extract for Enhanced Antioxidant and Anti-Inflammatory Activities in vitro

Aim: Cyperus rotundus L. (CR) is traditionally used in medicine for its anti-inflammatory properties. In particular, alpha-cyperone, which is isolated from the essential oil and found primarily in the n-hexane fraction of the ethanolic extract, is known to inhibit NO production in LPS-stimulated RAW 264.7 cells. However, high concentrations of alpha-cyperone are required for sufficient antiinflammatory activity. Even, essential oil obtained from C. rotundus has the disadvantage of low solubility and stability in aqueous environment, which makes it difficult to be applied in various fields and easily loses its activity. Therefore, in this study, we aimed to increase the extraction yield of C. rotundus by microbubble extraction and prepare nanoparticles (NPs) that can preserve its activity in a stable and bioavailable manner by utilizing nanoprecipitation. Methods: C. rotundus rhizomes were extracted in 50% ethanol using microbubbles and then fractionated with n-hexane to obtain alpha cyperone-rich C. rotundus n-hexane fraction (CRHF). The biodegradable plant extract, alpha-cyperone, was prepared as green nanoparticles (CR@NPs) by nanoprecipitation technique under mild reaction conditions. The physicochemical properties of CR@NPs, including size, polydispersity index, and surface charge, were determined using dynamic light scattering. The extraction yield and encapsulation efficiency of alpha-cyperone were quantified by high-performance liquid chromatography. Antioxidant and antiinflammatory activities were evaluated by DPPH assay and in vitro ROS and NO assays, and biocompatibility was assessed by MTT assay. Results: C. rotundus loaded nanoparticles demonstrated overcoming the limitation of alpha-cyperone solubility and stability in CRHF and also the antioxidant, anti-inflammatory properties as evidenced by in vitro assays in cellular models. Conclusion: The versatility of green chemistry, such as alpha-cyperone, enables the production of nanoparticles with promising biomedical applications such as cosmetics, pharmaceuticals, and food products.