Antimicrobial, modulatory and chemical analysis of the oil of Croton limae

Abstract

Context:Croton sp. are plants with a well-reported antimicrobial activity. Croton limae A.P. Gomes, M.F. Sales P.E. Berry (Euphorbiaceae), known as ‘marmeleiro-prateado’, is commonly used to manage abdominal pain in Brazil.Objective: This work evaluates the phytochemical composition, antimicrobial and modulatory activities of the essential oil of C. limae leaves (EOCL).Materials and methods: The minimum inhibitory concentration (MIC) and the modulation of the antibiotic activity were determined using a microdilution method. The concentration of EOCL ranged between 512 and 8 μg/mL. Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Candida tropicalis, C. krusei and C. albicans strains were used in the MIC and modulation assays. The antibiotics, amikacin, gentamicin and neomycin, and the antifungals, amphotericin B, benzoylmetronidazole and nystatin, were used in concentrations ranging between 2500 and 2.5 μg/mL. The phytochemical analysis of the EOCL was performed through gas chromatography coupled to a mass spectrometer (GC/MS).Results: Only Staphylococcus aureus was inhibited by a clinically relevant concentration of EOCL (MIC 512 μg/mL). Synergism between the EOCL and amikacin against S. aureus (9.76 μg/mL) and E. coli (39.062 μg/mL); neomycin against E. coli (2.44 μg/mL); and benzoylmetronidazole against C. krusei (256 μg/mL) were observed. The GC/MS analysis identified cedrol, eucalyptol and α-pinene as the main compounds of EOCL.Conclusion: EOCL inhibited the growth of S. aureus and potentiated the antibiotic and antifungal effects of drugs against all bacterial and Candida strains, respectively.

Chemical Constituents and Biological Activities of Croton heliotropiifolius Kunth

“…Accordingly, different classes of natural products have been shown to be able to modulate resistance to azoles [ 67 ]. The present study demonstrated the modulating effects of the ethanolic extract of C. heliotropiifolius roots, corroborating previous work that found similar effects for plants of the same genus against Candida strains [ 69 , 70 ].…”

“…Based on previous studies, it is reasonable to assume that this effect may be due to the presence of components such as carboxylic acids, terpenes [ 55 , 58 ], and phenolic compounds [ 69 ]. However, further research is required to investigate the action of isolated compounds.…”

Development and Evaluation of Antimicrobial and Modulatory Activity of Inclusion Complex of Euterpe oleracea Mart Oil and β-Cyclodextrin or HP-β-Cyclodextrin

“…Similarly to what observed by Pinheiro et al [2], HP-β-CD showed an endothermic peak ( Figure 6B) with Tonset = 37.25 °C (ΔH = 6.47 J/g and Tpeak = 37.05 °C) related to water release from its β-CD exhibited an endothermic peak ( Figure 6A) involving ∆H = 231.02 J/g with Tonset = 30.94 • C and Tpeak = 73.71 • C, likely due to water release from its cavity, and a second event occurred at Tonset = 223.50 • C (∆H = 0.75 J/g and Tpeak = 226.68 • C), similarly to the observations of Nascimento et al [3]. It was not possible to identify eventual endothermic events related to β-CD mass loss at high temperatures [2,40] because a maximum temperature of 300 • C was set in this study. β-CD complexes obtained by KND and SL showed similar behavior ( Figure 6A) with Tonset = 27.07 • C (∆H = 48.46 J/g and Tpeak = 42.72 • C) and 24.07 • C (∆H = 142.10 J/g and Tpeak = 48.86 • C), respectively, both related to dehydration, but occurring at lower temperatures when compared to β-CD.…”

Essential Oil of Croton ceanothifolius Baill. Potentiates the Effect of Antibiotics against Multiresistant Bacteria

“…Studies show that natural products without antibacterial activity can potentiate the effect of certain antibiotics, which is known as synergism [19]. The C. ceanothifolius essential oil is characterized by the presence of bicyclogermacrene, germacrene D and caryophyllene sesquiterpenes as major compounds (Table 1).…”