Persea americana Mill. (Lauraceae): análise fitoquímica e potencial antinociceptivo e anti-inflamatório

Abstract

The use of plants in traditional medicine is an age-old practice based on secondary metabolites with therapeutic properties. This study investigated the pharmacological safety and efficacy of Persea americana Mill. (avocado), focusing on the seed of the fruit. The main objective was to evaluate the antinociceptive and anti-inflammatory potential of the ethanolic extract of P. americana seed (EEPa) on in vitro and in vivo models, in addition to performing liquid-liquid fractionation and phytochemical analysis of the extract and its fractions. EEPa was obtained by macerating the seeds in 96% ethanol for 15 days. Liquid-liquid partitioning of EEPa was performed, resulting in four fractions: aqueous (FrAq), chloroform (FrClo), dichloromethane (FrDcm), and hexane (FrHex). Phytochemical analyses included thin layer chromatography (TLC), which detected terpenes and flavonoids in EEPa and its fractions. Polar compounds were concentrated in FrAq, while apolar compounds predominated in FrHex and FrDcm fractions. High-performance liquid chromatography (HPLC-DAD) revealed the presence of phenolic compounds and flavonoids, such as catechin, epicatechin, orientin, rutin, vitexin/isovitexin, and coumarin. In vitro tests demonstrated that EEPa did not show significant cytotoxicity in Neuro-2A and RAW 264.7 cells and inhibited the production of nitric oxide (NO) in macrophages stimulated with LPS, with a more pronounced effect at doses of 50 to 100 µg/mL. In vivo models, chemical nociception tests (abdominal contortion induced by acetic acid), and thermal nociception (hot plate) confirmed the antinociceptive effect of EEPa. It significantly reduced abdominal contortions at all doses tested, with the 2 mg/kg dose being the most effective (89.7%). The hot plate test showed an increase in pain threshold, indicating action in the central nervous system. EEPa also demonstrated anti-inflammatory activity in the thioglycollate-induced peritonitis model, reducing leukocyte migration to the peritoneal cavity at all doses. Differential analysis indicated a reduction in mononuclear cell migration, protein concentration, and levels of chemoattractants such as MCP-1 and KC. Biomonitoring of the fractions was performed in the formalin model. FrDcm was the most effective in phase 1, neurogenic pain (46% inhibition), while FrClo stood out in phase 2, inflammatory pain (62% inhibition). These results suggest that EEPa and its fractions contain promising bioactive compounds for the development of new therapies against pain and inflammation. This study highlights the therapeutic potential of medicinal plants and the importance of phytochemical and pharmacological research in the creation of new therapeutic approaches, reinforcing the relevance of the safe and effective use of plants in modern medicine.