Dietary intervention with purple passion fruit peel in asthma: insights into Th2-mediated responses in an ovalbumin-induced murine model.

Asthma is a chronic inflammatory airway disease in which Th2-driven immune responses and oxidative stress play key roles in its pathophysiology and are increasingly recognized as being modulated by diet. Purple passion fruit peel (PPFP), an agro-industrial by-product rich in dietary fiber and containing a diverse profile of bioactive compounds, including anthocyanins, represents a promising food-derived ingredient. However, most evidence on its effects in asthma relies on isolated extracts, and the mechanistic interplay of whole-food matrices remains poorly understood. In this study, female BALB/c mice were randomized into five groups: healthy control (CT), ovalbumin-induced asthma control (CA), positive control (dexamethasone), and asthma groups supplemented with 0.3% (PPFP-L) or 3.0% (PPFP-H) PPFP. Following intraperitoneal sensitization and intranasal OVA challenge, the effects of dietary supplementation on inflammatory mediators, oxidative stress markers, hepatic safety, and lung morphology were evaluated. Dietary inclusion of PPFP at 0.3% and 3.0% (non-cytotoxic in Aliivibrio fischeri) did not affect feeding behaviour, body weight, or hepatic toxicity markers. Supplementation at 3.0% significantly increased total reduced glutathione (41.7%) and the activities of catalase (19.8%) and superoxide dismutase (45.7%). Concurrently, systemic immunoglobulin E (15.9%) and pulmonary interleukin-4 (29.8%) and interleukin-5 (29.1%) levels were reduced, which was corroborated by decreased inflammatory cell infiltration in lung tissue. Conversely, lipid peroxidation and interleukin-13 production remained unaffected. These results indicate that PPFP mitigates oxidative stress primarily through the enhancement of antioxidant enzymatic homeostasis and modulation of Th2-driven systemic inflammation. Overall, PPFP emerges as a safe, minimally processed nutritional coadjuvant, supporting diet-based strategies to modulate chronic inflammation while promoting sustainable valorisation of food industry by-products.