Potencial antioxidante, neuroprotetor e antiacetilcolinesterásico da casca e caroço de Persea americana.

Abstract

The avocado, Persea americana, belongs to the Lauraceae family, and was originated in Central America. The fruit is very consumed in Brazil. During the production chain many foods are not used in their integrality, such as avocado, whose barks and seeds are discarded, not being used as food. It is estimated that approximately 30% of avocato fruit are discarded into the trash. Like avocado, other foods are not fully used, generating waste. This has attracted the attention of international entities such as the United Nations, which proposed 17 Sustainable Development Goals (SDGs) to end hunger and develop sustainable growth. In addition, various agri-food residues have biological activity, and can be used to improve people's quality of life. This study aims to analyze residues from P. americana (barks and seeds), in the form of hexane and ethanol extracts. The extracts were evaluated for antioxidant capacity, lipid profile, phytoconstituents, evaluation of antiacetylcolinesterase activity and neuroprotective capacity through the negative geotaxia assay, using Drosophila melanogaster model. The yields of the hexane extracts of barks and seeds were 1.32 and 0.911% respectively, and 15.98% for barks peels and 27.75% for seeds ethanol extracts. Some minerals were quantified by atomic absorption, with 26.78±2.06 Ca, 23.87±3.09 Mg, 0.20±0.74 Cu, 0.72±2.06 Fe, 4.23±10.34 and 0.67±7.02 Zn in the barks. In the lumps, 41.14±8.5 Ca, 31.41±1.82 Mg, 0.48±0.01 Cu, 1.04±7.4 Fe, 1.8±6.48 Mn and 1.11±0.57 Zn were quantified in the seeds. Analysis of the lipid profile of hexane and ethanol extracts by gas chromatography showed linoleic acid as the main constituent. Infrared spectra showed similarity between the extracts, indicating the presence of functional groups belonging to fatty acids. The 1H NMR spectra were also similar for all extracts with signs that corroborate the presence of fatty acids. The metabolic profile by HPLC of the ethanol extract from barks (CSC-ET) was more complex than the ethanol extract of the seeds (CRÇ-ET), the latter presenting an intense peak in retention time 16 min. Ethanol extracts were shown to possess alkaloids, as visualized with Dragendorff reagent. CSC-ET extract showed presence of flavonoids according to NP/PEG reaction. Ethanol extracts (CSC-ET and CRÇ-ET) showed indicative of the presence of condensed tannins. In total antioxidant assay (mmol/g of ascorbic acid) CRÇ-H extract presented 770 ± 0.024, CRÇ-ET extract 697 ± 0.072, CSC-H extract 669 ± 0.086 and 630 ± 0.039 for CSC-ET extract. CSC-ET extract showed the higher total phenolic content (35,404 ± 0.599) statistically significant. In ferric reducing power assay, CRÇ-H extract presented an average percentage of 4.065 ± 1.213 and CRÇET extract 2.383 ± 0.242; extracts from the barks exhibited 4.812 ± 1.376 (CSC-H) and 1.113 ± 0.252 (CSC-ET). The contents of total flavonoids of hexane extracts (CSC-H and CRÇ-H) were higher than those of ethanol extracts (CRÇ-ET and CSC-ET). The extracts also presented antifungal activity against Aspergillus niger (DL100 = 25 μg/mL). For antiacetylcolinesterase activity all extracts presented an average inhibition above 50%, CSC-ET being the most active one (85.6±11.053). Ethanol extract from the seeds (CRÇ-ET) presented the best performance in neuroprotection assays. The results showed that avocado peels and seeds contain bioactive compounds that can be reused, adding value to the production chain of avocado, making it more sustainable.