Bergamot by-product, a source of biogenic amines, reduces hypertension induced by high sugar-fat diet

Abstract

The high-sugar fat diet (HSF) generates hypertension. Bergamot by-product (BBP) is a source of hydrophilic bioactive compounds. The aim was to test BBP administration against hypertension induced by the HSF. The 48 male Wistar rats were equally divided into 4 groups: control diet (C), C+BBP, HSF, and HSF+BBP. The BBP (250 mg/Kg) was administrated by gavage for 20 weeks. The total phenolic compounds, carotenoids, and antioxidant capacity of BBP were evaluated by spectrophotometry, and HPLC was used to evaluate the biogenic amines (BAs) profile. The animals' body weight (BW), caloric intake, glucose levels, superoxide dismutase activity, and systolic blood pressure (SBP) were measured at the final of the experiment. Results showed that BBP is a good source of bioactive compounds, such as phenolic compounds (15 ± 2.1 µg Gallic Acid Equivalents/mg, w-w) and flavonoids (5.09 ± 0.22 µg Quercetin Equivalents/mg, w-w), and has a high antioxidant capacity (5.35 ± 0.06 µg Trolox Equivalents (TE)/mg, w-w; 1.30 ± 0.14 µg TE/mg, and 2.54 ± 0.31 mM FeSO/mg), by three different methods). BBP contains the BA histamine (28.4 ± 3.1 µg/g, w-w), tyramine (6.39 ± 0.39 µg/g, w-w), tryptamine (186 ± 11 µg/g, w-w), putrescine (29.0 ± 4.4 µg/g, w-w), cadaverine (10.6 ± 0.8 µg/g, w-w), spermidine (34.8 ± 4.3 µg/g, w-w), spermine (2.28 ± 0.25 µg/g, w-w), serotonin (4.46 ± 0.77 µg/g, w-w), dopamine (2.50 ± 0.29 µg/g, w-w), and agmatine (140 ± 10 µg/g, w-w). BBP has remarkable levels of antioxidant BAs, such as spermidine (34.8 ± 4.3 µg/g, w-w) and agmatine (140 ± 10 µg/g, w-w). HSF increased BW (532 ± 72 g VS 474 ± 36 g (C), p<0.001), glucose levels (91.4 ± 6.2 mg/dL VS 80.9 ± 7.1 mg/dL (C), p<0.001) and SBP (146 ± 9 mmHg VS 121 ± 5 mmHg (C), p<0.001). BBP reduced hypertension generated by HSF (133 ± 9 mmHg VS 146 ± 9 mmHg, p<0.001), suggesting a direct hypotensive action. The synergy between the bioactive compounds identified in BBP demonstrates great potential for use to prevent and treat hypertension.