Abstract
Callistemon citrinus has shown antioxidant and anti-inflammatory properties in certain tissues. However, its impact on the brain remains unproven. This study investigates the effect of C. citrinus extract and phytosomes on the oxidative status of the brains of rats fed a high-fat-fructose diet (HFD). Fifty-four male Wistar rats were randomly divided into nine groups (n = 6). Groups 1, 2, and 3 received a standard chow diet; Group 2 also received the vehicle, and Group 3 was supplemented with C. citrinus extract (200 mg/kg). Groups 4, 5, 6, 7, 8, and 9 received a high-fat diet (HFD). Additionally, groups 5, 6, 7, 8, and 9 were supplemented with orlistat at 5 mg/kg, C. citrinus extract at 200 mg/kg, and phytosomes loaded with C. citrinus at doses of 50, 100, and 200 mg/kg, respectively. Administration was oral for 16 weeks. Antioxidant enzymes, biomarkers of oxidative stress, and fatty acid content in the brain were determined. A parallel artificial membrane permeability assay (PAMPA) was employed to identify compounds that can cross the intestinal and blood-brain barriers. The HFD group (group 4) increased body weight and adipose tissue, unlike the other groups. The brain fatty acid profile showed slight variations in all of the groups. On the other hand, group 4 showed a decrease in the activities of antioxidant enzymes SOD, CAT, and PON. It reduced GSH level, while increasing GPx activity as well as MDA, 4-HNE, and AOPP levels. C. citrinus extract and phytosomes restore the antioxidant enzyme activities and mitigate oxidative stress in the brain. C. citrinus modulates oxidative stress in brain tissue through 1.8-cineole and α-terpineol, which possess antioxidant and anti-inflammatory properties.