Characterization of Persea americana Mill. peels and leaves extracts and analysis of its potential in vitro anti-inflammatory properties

There is a worldwide trend of increasing prevalence of non-communicable diseases characterized by a chronic inflammatory state. Therefore, it is important to study the relationship between food and health. Avocado (Persea americana) stands out in food industry for its nutritional value. Industrials process of avocado generates a large number of by-products, which contain phytochemical compounds with antioxidant properties, such as polyphenols. The objective of the present research was to characterize four aqueous and hydroalcoholic extracts from avocado leaves and peels and analyze it possible anti-inflammatory properties in vitro. Total polyphenol content (with the Folin-Ciocalteau method) and antioxidant capacity (by FRAP and DPPH) were determined. Extracts inflammatory features were measured by NO and TNF-alpha release, and by TNF-alpha gene expression. Our results indicated that hydroalcoholic extracts present higher total polyphenol content (p<0.001) and antioxidant capacity (p<0.001, by FRAP) than the aqueous ones. Furthermore, we report that hydroalcoholic leaves extract presented greater in vitro anti-inflammatory effect, especially the leave hydroalcoholic regarding NO release (p<0.001, against LPS treatment), aqueous and hydroalcoholics regarding TNF-alpha release (p<0.05), and only the hydroalcoholic in the TNF-alpha gene expression (p<0.01). In conclusion, the avocado hydroalcoholic extracts, and especially from leaves, present in vitro anti-inflammatory features that might be considered for human health improvement applications.