Anti-inflammatory activity of orange peel aqueous extract and hesperidin: integrated evidence from neutrophil assays, in vivo models, and in silico analyses

Abstract

Citrus peels have traditionally been used for their anti-inflammatory properties. Their bioactive compounds can modulate neutrophil activation and reduce ROS production, both of which play key roles in the development of many chronic inflammatory diseases. The present study aimed to investigate the anti-inflammatory potential of an orange peel aqueous extract (OPE) and its major flavonoid, hesperidin (HSP), using integrated in vitro, in vivo, and in silico approaches. The anti-inflammatory activities of OPE and HSP were first assessed in isolated human neutrophils through degranulation and total ROS production assays. In vivo effects were evaluated in male Wistar rats using xylene-induced ear edema and λ-carrageenan-induced peritonitis models. In silico molecular docking analyses were performed to predict the interactions of hesperidin with key inflammatory targets. In vitro, OPE and HSP significantly inhibited ROS production in neutrophils stimulated with PMA and fMLF and markedly reduced neutrophil degranulation. In vivo, pretreatment with OPE or HSP resulted in a substantial decrease in ear edema and neutrophil infiltration in peritoneal exudates, with comparable effects to those of aspirin. Docking results showed strong predicted binding affinities of hesperidin for NADPH oxidase subunits, cyclooxygenases-1 and -2, p38 MAPK, and NF-κB. Collectively, these findings demonstrate that OPE and HSP exhibit potent anti-inflammatory effects via multiple complementary mechanisms, supporting the valorization of citrus by-products as nutritionally relevant functional ingredients with potential applications in the dietary management of inflammation-related disorders.