Prevention of UVB radiation-induced oxidative stress in mice by topical administration of Azadirachta indica (neem) extract

  • Renata Micheli Martinez Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Clara Ruiza de Souza Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Cristina de Paula Barros de Melo Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Marcela Maria Baracat Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Nilton Syogo Arakawa Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • José Carlos Duarte Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Waldiceu Aparecido Verri Jr. Departamento de Patologia, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Rúbia Casagrande Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
  • Sandra Regina Georgetti Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina (UEL), Londrina, PR, Brasil
Keywords: antioxidant, neem, oxidative stress, UVB irradiation, topical formulation

Abstract

Neem tree (Azadirachta indica A. Juss. fam. Meliaceae) has been extensively employed to combat diverse pathologies. Moreover, it has been described that its leaf extract present anticarcinogenic action. Thus, the neem extract (NE) chemical and antioxidant properties was evaluated, and also, the capacity of two dermatological formulations incorporated with neem extract (F1 and F2) to avoid oxidative UVB-induced skin injury in hairless mice. NE constituents were investigated and free radical scavenging ability were determined by different methods in vitro. Skin from mice treated with F1 and F2 and submitted to UVB radiation were tested for different parameters of inflammation and oxidative injury. Results show that the NE polyphenol and flavonoid content were 135.30 and 37.12mg/g, respectively. High performance liquid chromatography (HPLC) results demonstrated the existence of azarachtin, rutin, ursolic acid and tannic acid. NE presented scavenging ability by ABTS radical, ferric-reducing antioxidant power (FRAP), inhibition of lipid peroxidation and iron chelation. In vivo, it was observed that mice treated with F1 and F2 showed amelioration of the inflammation by reducing UVB induced skin edema. However, only samples from animals treated with F1 had lower neutrophil recruitment (measured by myeloperoxidase activity), and returning the oxidative status to baseline levels in parameters such as reduced glutathione level, ferric reducing ability (FRAP), and scavenging of free radical (ABTS). Concluding, NE demonstrated a good antioxidant property in vitro, and the data suggest the use of NE added F1 to prevent skin damage caused by UVB irradiation.

Published
2020-08-17
Section
Research Article