Chemical constituents of leaves of Persea americana (avocado) and their protective effects against neomycin-induced hair cell damage

Persea americana Mill., Lauraceae, commonly known as the avocado, is native to tropical and subtropical regions, including Brazil. From the leaves of P. americana, one previously undescribed flavonol glycoside (1) together with ten known flavonoids (2–11), four megastigmane glycosides (12–15) and two lignans (16–17) were isolated. Their structures were determined by extensive spectroscopic methods including 1D- and 2D-nuclear magnetic resonance and mass spectrometry data. This is the first investigation that reports megastigmane glycoside and lignan classes within the genus Persea. All the isolated compounds have been assessed through the cell survival of larval zebrafish following neomycin-induced damage and the cell viability of a House Ear Institute-Organ of Corti 1 mouse auditory cell line. Among the tested compounds, juglanin (2) and (+)-lyoniresinol (16) showed significant cell regeneration in neomycin-damaged hair cell without cellular toxicity.