Effects of Psidium guajava L. leaves extract on blood pressure control and IL-10 production in salt-dependent hypertensive rats
Daiane Cristina de Assis Braga, Paula Magalhães Gomes, Marcos Adriano Carlos Batista, Jaqueline Aparecida de Souza, Juliana Cristina Santos Almeida Bastos, Rosana Gonçalves Rodrigues-das-Dôres, Andréia Carvalho Alzamora, Gustavo Henrique Bianco de Souza, Sandra Aparecida Lima de Moura, André Talvani, Vagner Roberto Antunes, Leonardo Máximo Cardoso
Abstract
Psidium guajava (guava) leaves extract displays anti-hypertensive properties by mechanisms not yet fully understood. Here, we investigated whether sympathetic drive and immune signaling mechanisms are involved with the antihypertensive effect of the guava extract in a model of salt-dependent hypertension. Raw guava extract (r Ps E) was characterized by colorimetric and UPLC-MS techniques. Two doses of r Ps E (100 and 200 mg/kg) were evaluated for anti-hypertensive effect using a suspension system ( Ps E). Weaned male Wistar rats were put on a high-salt diet (HSD, 0.90 % Na + ) for 16 weeks and received gavages of Ps E for the last 4 weeks. Blood pressure (BP) was measured at the end of treatment in conscious rats. The neurogenic pressor effect was assessed by ganglionic blockade with hexamethonium . Autonomic modulation of heart rate was evaluated by spectral analysis . The effects of orally administered Ps E on lumbar sympathetic nerve activity (LSNA) were assessed in anesthetized rats. Blood IL-10, IL-17A, and TNF were measured. The increased neurogenic pressor effect of HSD rats was reduced by Ps E 100 mg/kg, but not by 200 mg/kg. Ps E (200 mg/kg) administration in anesthetized rats produced a greater fall in BP of HSD rats compared to standard salt diet (SSD) rats. Ps E hypotensive response elicited an unproportionable increase in LSNA of HSD rats compared to SSD rats. Ps E (200 mg/kg) increased plasma concentrations of IL-10 but had no effect on TNF or IL-17A. Our data indicate that the antihypertensive effects of Ps E may involve autonomic mechanisms and immunomodulation by overexpression of IL-10 in salt-dependent hypertensive rats.