Flavonoid-rich sesame leaf extract-mediated synthesis of nanozymes: Extraction optimization, chemical composition identification and bioactivity evaluation

Sesame leaves contain rich phenolic acids and flavonoids. However, their potential in nanozyme synthesis has not been investigated yet. Herein, we report the preparation of flavonoid-rich sesame leaf extract (SLE), composition identification, and its use in the construction of iron (Fe)-based nanozymes (Fe-SLE CPNs). SLE was obtained with an extraction yield of ∼14.5% with a total flavonoid content (TFC) of ∼850.85 mg RE/g. There were 83 flavonoid compounds in SLE, primarily including scutellarin, apigenin-7-glucuronid, narcissin, and hyperoside. Fe-SLE CPNs exhibited nanodot morphology with a hydrodynamic size of 79.34 nm and good stability in various physiological solutions, pH levels, and temperatures. The Fe-SLE CPNs were more efficient in the scavenging ability of reactive oxygen species (ROS) than SLE alone. Furthermore, a stronger anti-inflammatory effect of the Fe-SLE CPNs was shown by modulating the MyD88-NF-κB-MAPK signaling pathways. These findings imply that SLE-based nanozymes hold great potential for diverse applications.