Composición química y actividad biológica de los extractos de las partes aéreas de Leonurus japonicus (Houtt.).

Leonurus japonicus Houtt. (Lamiaceae), is a specie that has been studied in the last three decades, many researchers have focused on determining their chemical composition, pharmacological activities and their applications, managing to isolate more than 280 chemical compounds of this. The objective of this research was to study the chemical composition and biological activity of the extracts obtained from the aerial parts of L. japonicus, collected in Merida, Venezuela. Preliminary phytochemical studies showed the presence of sterols in hexanoic and dichloromethane extracts, and alkaloids, phenols compounds, flavonoids and sterols in the ethanolic extract. In present investigation, the ethanolic extract had a total phenolic content of 0.89 µg AG/mg extract. The antioxidant activity was determined using the DPPH method (2.2-diphenyl-1-picrylhydrazyl) using spectrophotometry UV-visible at a wavelength of 517 nm. The ethanolic extract showed an IC50 of 0.457 mg/mL, at the concentration of 0.5 mg/mL, inhibition percentages of these radicals was 57.7% compared to 96.1% of the ascorbic acid, used as a positive control, at the concentration of 0.176 mg /mL. In addition, this extract proved to be relatively harmless on Artemia salina nauplii, with a lethality percentage of 8.3 to 2500 ppm, and the LD50 of 2913.55 ppm. It should be noted that this is the first report of antioxidant activity, quantification of total phenols and toxicity on A. salina from the extracts of L. japonicus, collected in Venezuela.