Análise do extrato e constituintes químicos de Erythrina verna vell. sobre o crescimento, in vitro, de estreptococos do grupo mutans e toxicidade aguda em modelo experimental murino

Abstract

Erythrina verna Vell. (EV) is a native Brazilian plant commonly used in folk medicine, mainly as a tranquilizer and also in the treatment of infections. Although herbal compositions are commercialized with this species, few studies on the chemical and toxicological profile have been reported. The aim of the study was to evaluate the biological and toxicological activity of the bark extract of Erythrina verna Vell.. The phytochemical profile of the E. verna extract (EVE) was determined by gas chromatography coupled to mass spectrometry, and the Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of the butanoic extract of EV bark and chemical constituents were identified against isolates from mutans group streptococci (MGS). In addition, we analyzed the synergistic effect of the active compounds in the extract. Acute toxicity was assessed according to the Organization for Economic Co-operation and Development protocol (OECD 423). A single dose of the extract at concentrations of 5, 50, 300 and 2000 mgKg-1 (n=3/group) was orally administered to Swiss mice. The animals were monitored for 14 days along with the evaluation of clinical, biochemical and histopathological signs, as well as the presence of mortality. EVE showed secondary metabolites and substances with antimicrobial activity, benzoic acid and azelaic acid. Of the three compounds isolated from EVE, stearic acid showed the highest bactericidal activity against the microorganisms tested. However, comparing the bactericidal activity of the crude extract and the isolated chemical constituent, EVE showed more effective antibacterial activity, while those from the oral cavity (C17VA, C12VA and C04PD) showed greater resistance to the extract and to stearic acid compared to the standard strains (ATCC 25175 and ATCC 27392). EVE demonstrated a synergistic effect when associated with chlorhexidine, with a reduction of about 98% of the bacterial population in all tested microorganisms. On the other hand, acute toxicity did not produce mortality or behavioral and hematological changes, however, there were changes in HDL levels significantly elevated when compared to animals in the control group. The histological examination of the spleen, heart and kidney showed changes in tissue architecture with foci of inflammatory infiltrates from a concentration of 50 mgKg-1 . E. verna bark extract can be an alternative in the treatment of diseases caused by mutans group streptococci, especially if associated with chlorhexidine. However, the oral use of E. verna bark extract should be performed with caution and in low doses.