Identification of TRPV1 ion channels agonists in Tropaeolum tuberosum

Abstract

Tropaeolum tuberosum, commonly known as Mashua, is an herbal remedy used in traditional Andean medicine (Peruvian-Bolivian) for the relief of kidney and bladder pain, as well as contusions. This study aims to assess the analgesic activity of Tropaeolum tuberosum fractions and isolated compounds mediated through the TRPV1 receptor. A bioguided phytochemical analysis was performed in order to identify both agonist and antagonist compounds by 1H- and 13C NMR of n-heptane fractions from samples of purple tubers. The study detected intracellular Ca2+ and the agonist or antagonist activity on TRPV1 in HEK001 cells. The chemical structure determination led to the identification of two alkamides: N-(2-Hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (1) and N-oleoyldopamine (2). Both compounds induced increased intracellular calcium flow with IC50 values of 2.97±0.13 nM and 1.70±0.10 nM, respectively, thus activating the TRPV1 receptor. This is the first evidence that N-(2-Hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (1) and N-oleoyldopamine (2) isolated from T. tuberosum act as agonists of the TRPV1 receptor, and, as a consequence, the study contributes to the literature by providing scientific basis for the traditional use of this species in pain relief