Evaluation of the toxicity and antimicrobial activity of hydroethanolic extract of Arrabidaea chica (Humb. & Bonpl.) B. Verl.
BACKGROUND
Arrabidaea chica (Bignoniaceae) is a vine native to the Amazon Rainforest, popularly known as "crajiru" and whose infusion and decoction of the leaves are used to treat diseases such as gastric ulcers, inflammations, infections, anemia, herpes, jaundice among others. It is also used as a natural dye. This work aimed to evaluate the in vitro and in vivo toxicity, antimicrobial activity including analysis of chemical constitution of the hydroethanolic extract of the leaves of Arrabidaea chica (HEAc).


METHODS
Acute and subchronic toxicity of HEAc was evaluated in mice and rats, respectively, and by Alamar blue (cytotoxicity assay) using CHO-K1 cells. Antimicrobial activity of HEAc was tested by broth microdilution method using a panel of bacteria and yeast of clinical interest. The preliminary phytochemical analysis of HEAc was performed by electrospray ionization mass spectrometry [ESI(+)-MS]. Secondary metabolites were quantified by colorimetric methods.


RESULTS
When administered in vivo at doses up to 3000 mg/kg v.o., HEAc did not cause any signs and symptoms of acute toxicity in mice and no cytotoxicity in CHO-K1 cells. Administration for 30 days caused leukocytosis (200 mg/kg) and reversible reductions in non-dose dependent of body weight, total weight gain and feed intake in rats given 200mg/kg and 500 mg/kg of HEAc, but were not accompanied by behavioral and clinical changes (laboratory and histopathological) that may have demonstrated evidences of subchronic toxicity HEAc demonstrated a pronounced activity against Helicobacter pylori (MIC=12.5 μg/mL) and moderate activity against Enterococcus faecalis (MIC=100 μg/mL) in broth microdilution. Preliminary phytochemical analysis of HEAc by colorimetric methods revealed that mainly the presence of phenolic compounds (16.6%), especially flavones and flavonols (4.02%). [ESI(+)-MS] fingerprint analyses of HEAc revealed the presence of 3-deoxyanthocyanidins and kaempferol.


CONCLUSIONS
Our data provide evidence that HEAc is safe and can be useful in infections related to Helicobacter pylori and Enterococcus faecalis. Phytochemical analysis revealed the predominant presence of flavones and flavonols, possibly involved in the antimicrobial action of HEAc.
Department of Basic Sciences in Health, Faculty of Medicine, Federal University of Mato Grosso (UFMT), Av. Fernando Correa da Costa, no 2367, Boa Esperança, Cuiabá, Mato Grosso 78060-900, Brazil.
Luciano
L
Mafioleti
Iberê Ferreira
IF
da Silva Junior
Edson Moleta
EM
Colodel
Adriana
A
Flach
Domingos Tabajara de Oliveira
DT
Martins
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects; D029402:Bignoniaceae; D016466:CHO Cells; D003412:Cricetulus; D013293:Enterococcus faecalis / Q000187:drug effects; D000431:Ethanol / Q000737:chemistry; D005260:Female; D016480:Helicobacter pylori / Q000187:drug effects; D008297:Male; D051379:Mice; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology* / Q000633:toxicity; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D012997:Solvents; D014867:Water; D000431:Ethanol
Amazonian forest; Antimicrobial; Arrabidaea chica; Medicinal plants; Phenolics