"Antiviral activity of fractions of aqueous extract obtained from Achyrocline satureioides (Lam.) D.C. against Western Equine Encephalitis virus”.

SABINI MARÍA CAROLA; ESCOBAR FRANCO MATÍAS; CARIDDI LAURA NOELIA; SUTIL SONIA BEATRIZ; ZANON SILVIA MATILDE; SABINI LILIANA INÉS

Bento Gonçalves

Simposio; “XXII Simposio de plantas Medicinais do Brasil”; 2012

Universidade Federal do Rio Grande do Sul-Curso de Farmácia da UFCSPA

Introduction: Achyrocline satureioides (Lam.) D.C. (Asteraceae) is a medicinal plant traditionally used in South America for treat intestinal infections and digestive disorders. Its infusion is utilized for respiratory problems and viral infections. Viruses cause important diseases in humans and animals. Outbreaks of viral encephalitis are a health issue of increasing importance. Western equine encephalitis virus (WEEV) (Togaviridae) is an important pathological agent and there is no effective antiviral drug available for the treatment of this illness. Thus, it is necessary to develop new and efficient drugs. In previous studies we reported that cold aqueous extract (CAE) of A. satureoides has strong antiviral activity against WEEV. Therefore, this study was conducted to evaluate the cytotoxicity and antiviral activities of fractions of CAE of A. satureioides against WEEV. Experimental: Aerial vegetal parts were submitted to extraction with cold water (4ºC) for 48 hs. The suspensions were filtered and lyophilized. Dried extract (1 g) was eluted with MeOH (100%) to MeOH: H2O (9:1) in Sephadex LH20 column (2.5 x 20 cm). Fractions were collected and subjected to dryness. Cytotoxicity of fractions was determinate by Neutral Red Uptake on Vero cells. Then, antiviral activity against WEEV was tested at non-cytotoxic concentrations. The fraction active was submitted to HPLC/DAD analysis. Results: Fractions F1, F3, F4 and F5, showed non-cytotoxic effects at all concentrations tested (0-100 μg/ml). Contrary, F2 was more toxic with CC50 of 42 μg/ml. It was possible to determine that F3 was the active fraction against WEEV with 82% of inhibition. The HPLC–DAD chromatogram of F3 revealed the presence of two compounds. None of them coincided with chlorogenic, caffeic acid, rutin or quercetin. Conclusion: Fraction F3 of A. satureioides exerts high antiviral activity against WEEV. So, this plant is a promising natural antiviral for the treatment of alphavirus infection.