Nanoformulation, characterization, and biological activity assays of extracts of Derris trifoliata Lour, a rutin-rich mangrove plant

• The extract of Derris trifoliata Lour, a rutin-rich mangrove plant, was encapsulated in nanoemulsion to be used as a topical anti-inflammatory product for the first time. • The Derris trifoliata Lour extract-loaded nanoemulsion was highly stable and appeared to be safe to macrophage cells. • The Derris trifoliata Lour extract-loaded nanoemulsion demonstrated the superior antioxidant and anti-inflammatory activities over the Derris trifoliata Lour extract. Derris trifoliata Lour (DT) is a mangrove plant species with a promising anti-inflammatory effect. However, the application of DT as a topical anti-inflammatory agent is limited due to its poor bioavailability. Here, DT extract (DTE) from Kapoe District, Ranong Province, Thailand was selected due to its highest rutin over three investigated sources. The DTE was loaded into a nanoemulsion (NE), giving 74.33 ± 0.12 % and 75.29 ± 0.51 %, encapsulation efficiency of rutin and total phenolic content (TPC), respectively. The DTE-loaded NE (DTE-NE) exhibited a nano size (90.59 ± 1.27 nm) spherical, negative charge (-33.13 ± 0.12 mV), and narrow dispersity index (0.28 ± 0.01). The in vitro release profile of rutin and TPC from DTE-NE was slower compared to those from DTE. DTE-NE displayed a superior antioxidant capacity to DTE. Compared to DTE, DTE-NE treatment potentially lowered the inflammatory mediators (nitrite, interleukin-6, and tumor necrosis factor-alpha). Moreover, the physicochemical characteristics, antioxidant and anti-inflammatory activities remained unchanged after 1 month storage. In conclusion, the present study demonstrated the possible use of DTE-NE as a topical anti-inflammatory product.