Recently, the demand for supplements based on natural products has grown and they are now part of the daily life of the general population. Studies suggest that supplements with high antioxidant activity have a vital role in the prevention of various diseases, such as hypercholesterolemia, a disease characterised by high blood cholesterol. Currently, the drugs available to treat hypercholesterolemia have some adverse side effects related to their chronic use. Therefore, food supplements are a viable alternative.

In this work, an aqueous avocado extract was studied to assess its potential in treating hypercholesterolaemia. Initially, the extract was characterised by HPLC-DAD and LC-HRMS/MS, where phenolic compounds such as chlorogenic acid, epicatechin and catechin were identified. Catechin was quantified as the major compound (12 mg catechin/100 mg dry extract). The antioxidant activity of the extract was also determined with an EC50 of 5.8 ± 0.2 µg/mL. To use this extract as a supplement, a delivery nanosystem was selected, namely albumin nanoparticles (NPs). NPs with 5, 10 and 15 mg of extract were formulated and characterised. NPs with 15 mg of extract were the largest (401 ± 4 nm). Whereas NPs with 5 mg of extract presented a higher encapsulation efficiency (81 ± 5 %). Finally, to assess the safety of the extract, toxicity tests were performed on an intestinal and hepatic cell line model, where the IC50 was 0.240 mg/mL and 0.165 mg/mL, respectively. The subsequent phase consists of evaluating the extract effect on the cholesterol permeability through a gastrointestinal barrier model.