ABSTRACT
American foulbrood (AFB) is a serious worldwide spreading disease in bees caused by Paenibacillus larvae. Plants extracts are known to decrease or inhibit the growth of these bacteria. The purpose of this study was to evaluate the antimicrobial activity of Calendula. officinalis, Cariniana domestica, and Nasturtium officinale extracts against the P. larvae and to evaluate the toxicity of the extracts in bees. In vitro activity against P. larvae of the extracts was evaluated by micro dilution method and the minimal inhibitory concentrations (MICs) were also determined. The concentrations used in the toxicity test were established based on the MIC values and by the spraying application method. The P. larvae was susceptible to the evaluated crude extract of C. officinalis and N. officinale. To C. domestica, only the ethyl acetate (EtAc) fraction and n-butanol (BuOH) fractions had activity against P. larvae. Toxicity analysis in bees showed no toxicity for N. officinale crude extract and for C. domestica BuOH fraction during 15 days of treatment, however, some deaths of bees occurred during the first three days of treatment with C. officinalis and C. domestica EtAc fraction. The results with these species were firstly described and showed that N. officinale crude extract and C. domestica BuOH fraction both presented not toxic effects in the concentration tested by the spraying application method, and can be a useful alternative for treatment or prevention of AFB.
Subject(s)
Bees/drug effects , Calendula/chemistry , Lecythidaceae/chemistry , Nasturtium/chemistry , Paenibacillus/drug effects , Plant Extracts/pharmacology , Animals , Chromatography, High Pressure Liquid , Dose-Response Relationship, Drug , Gas Chromatography-Mass Spectrometry , Larva/drug effects , Microbial Sensitivity Tests , Plant Extracts/toxicity , Toxicity TestsABSTRACT
The antioxidant capacity of the crude extract and fractions of Tabernaemontana catharinensis fruits and branches, was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and the content of polyphenols, flavonoids, alkaloids and condensed tannins were determined by the spectrophotometric method. The ethyl acetate fraction of the fruits and the n-butanol fraction of the branches showed IC50 of 181.82 µg/mL and 78.19 µg/mL, respectively. All fractions were analyzed by high performance liquid chromatography (HPLC), in the branches were quantified chlorogenic acid in the chloroform (8.96 mg/g), ethyl acetate (4.31 mg/g) and n-butanol (3.33 mg/g) fractions; caffeic acid in the ethyl acetate (5.24 mg/g) and n-butanol (1.81 mg/g); gallic acid (0.52 mg/g) in the n-butanol. In the fruits, chlorogenic acid in the chloroform (1.67 mg/g); rutin in the ethyl acetate (3.45 mg/g) and n-butanol (8.98 mg/g) fractions. The present study showed that these quantified compounds can contribute to antioxidant capacity which was higher in the branches than in the fruits.
