Bioactivity of extracts from Baccharis crispa Spreng. (Asteraceae) against Chikungunya and Herpes simplex type I

LINGUA, G.; AGUILAR, J.J.; TORRES, L.E.; KONIGHEIM, B.S.

Cordoba

Jornada; Jornadas de Investigación Científica XIX; 2018

Viral infections recognized long ago in the old world begin to be a health problem for America (Chikungunya, Zika, etc.), for which there are no antivirals available. In addition to the emergence of resistant strains of other viral pathologies such as Herpes simplex type 1 (HSV-I). The search for new antivirals is a constant and current need. For this reason, we initially proposed to evaluate in vitro the cytotoxicity and the direct effect on the virus (virucidal capacity) of extracts of Baccharis crispa (carqueja), against Chikungunya (CHIKV) and HSV-1 viruses. Aqueous (EAc) and organic (chloroform, ECHCl3 and ethanolic, EEtOH) extracts were obtained from two wild carqueja populations from the province of Córdoba: Puesto Pedernera (PP) and Tala Cañada (TC). The Vero cell line was used for the in vitro tests. The cytotoxic concentration 50 (CC50) of each extract was obtained with the neutral red uptake method. The evaluation of the virucidal capacity, by the titration of the residual virus (the one that remains viable after been in direct contact with the extracts), using the reduction method of plaque forming units (PFU). The CC50 values obtained for the PP extracts were 92.96; 570.99 and 501.59 μg/mL for ECHCl3, EEtOH and EAc, respectively. While for TC the values were 104.44; 256.22 and 617.83 μg/mL, respectively. The population of PP, presented the best activity on both viruses, particularly EEtOH decreased in 5 logarithms the formation of PFU compared to its control; while ECHCl3 and EAc, achieved a decrease of 3 (CHIKV) and 4 (HSV-1) logarithms respectively. In general, TC was less effective, highlighting ECHCl3 without activity on the evaluated viruses; while EEtOH and EAc decreased the formation of PFU for both viruses by 2 and 3 logarithms.The results allow to conclude that there are differential cytotoxicity and virucidal activity among populations, with the PP population being the least cytotoxic and most active. Considering these results and the need to find new antivirals; it is promising to evaluate the antiviral capacity and the identification of the metabolites responsible for the observed activities.