Optimisation of Croton gratissimus Oil Extraction by n-Hexane and Ethyl Acetate Using Response Surface Methodology.

The extraction of oil from Croton gratissimus seeds was studied using the three-factor five-level full-factorial central composite rotatable design (CCRD) of the response surface methodology (RSM). The effect of the three factors selected, viz., extraction time, extraction temperature and solvent-to-feed ratio on the extraction oil yield was investigated when n-hexane and ethyl acetate were used as extraction solvents. The coefficients of determination (R2) of the models developed were 0.98 for n-hexane extraction and 0.97 for ethyl acetate extraction. These results demonstrated that the models developed adequately represented the processes they described. From the optimized model, maximum extraction yield obtained from n-hexane and ethyl acetate extraction were 23.88% and 23.25%, respectively. In both cases the extraction temperature and solvent-to-feed ratio were 35°C and 5 mL/g, respectively. In n-hexane extraction the maximum conditions were reached only after 6 min whereas in ethyl acetate extraction it took 20 min to get the maximum extraction oil yield. Oil extraction of Croton gratissimus seeds, in this work, favoured the use of n-hexane as an extraction solvent as it offered higher oil yields at low temperatures and reduced residence times.

Anti-edematogenic and anti-inflammatory activity of the essential oil from Croton rhamnifolioides leaves and its major constituent 1,8-cineole (eucalyptol).

The species Croton rhamnifolioides, belonging to the Croton genus, is known in ethnomedicine as "quebra faca" and is used in the treatment of stomach pain, vomiting and fever. This study aims to evaluate the anti-edematogenic and anti-inflammatory effect of Croton rhamnifolioides leaf essential oil (OEFC) and its major constituent: 1,8-cineole (eucalyptol). The essential oil was extracted from fresh leaves through a hydrodistillation system. The chemical analysis was determined by gas chromatography-mass spectrometry (GC-MS). The acute anti-inflammatory activity was determined from the models of: ear edema by the single application of croton oil, paw edema induced by: carrageenan, dextran, histamine and arachidonic acid, while vascular permeability was determined by Evans blue extravasation and chronic anti-inflammatory activity by granuloma induction using the implantation of cotton pellets. The GC-MS results identified and quantified 11 constituents, with the major component being 1,8-cineole (41.33%). The OEFC (20mg/mL) and 1,8-cineole (8.26mg/mL) significantly reduced the edema induced by croton oil by 42.1 and 34.9%, respectively. The OEFC (25, 50, 100 and 200mg/kg) and 1,8-cineole (10.33, 20.66, 41.33 and 82.66mg/kg) statistically reduced paw edema induced by carrageenan, dextran as well as vascular permeability (protein extravasation). The OEFC (25mg/kg) and 1,8-cineole (10.33mg/kg) demonstrated efficacy in reducing edema induced by histamine and arachidonic acid and granuloma. In conclusion, the OEFC and 1,8-cineole have anti-inflammatory activity in the acute and chronic phase, suggesting therapeutic potential as a source for the development of new anti-inflammatory agents.

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

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.

The sensitivity of bacterial foodborne pathogens to Croton blanchetianus Baill essential oil

The aim of this study was to assess the activity of essential oil extracted from the leaves of C. blanchetianus Baill, popularly known as "marmeleiro", in inhibiting the growth and survival of pathogenic microorganisms in food by determining their survival in vitro and by observing the behaviour of Listeria monocytogenes inoculated into a food model (meat cubes) that was stored at refrigeration temperature (7 ± 1 ºC) for 4 days. The results indicated a bactericidal effect against Aeromonas hydrophila and Listeria monocytogenes and bacteriostatic action against Salmonella Enteritidis. A bacteriostatic effect on meat contaminated with L. monocytogenes was found for all concentrations of essential oils tested. These results showed that essential oil from the leaves of C. blanchetianus Baill represents an alternative source of potentially natural antimicrobial agents that may be used as a food preservative.

The sensitivity of bacterial foodborne pathogens to Croton blanchetianus Baill essential oil.

The aim of this study was to assess the activity of essential oil extracted from the leaves of C. blanchetianus Baill, popularly known as "marmeleiro", in inhibiting the growth and survival of pathogenic microorganisms in food by determining their survival in vitro and by observing the behaviour of Listeria monocytogenes inoculated into a food model (meat cubes) that was stored at refrigeration temperature (7 ± 1 °C) for 4 days. The results indicated a bactericidal effect against Aeromonas hydrophila and Listeria monocytogenes and bacteriostatic action against Salmonella Enteritidis. A bacteriostatic effect on meat contaminated with L. monocytogenes was found for all concentrations of essential oils tested. These results showed that essential oil from the leaves of C. blanchetianus Baill represents an alternative source of potentially natural antimicrobial agents that may be used as a food preservative.

[GC-MS analysis of chemical components in seeds oil from Croton tiglium].

OBJECTIVE: To identify the chemical components and their relative content in seeds oil from Croton tiglium. METHODS: The oil obtained by extracting of the seeds of Croton tiglium with petroleum ether was subjected to methyl-esterification or dilution with ethylether. GC-MS were used to identify the components in croton oil,peak area normalization method was used to determine the relative content of these substances in the sample. RESULTS: Seventeen fat acid components were identified from croton oil. The main components were linoleic acid, oleic acid, and eicosenoic acid in methyl-esterified sample, whose quantities accouted for 77.33%. In addition, five aromatic compounds were also found in the sample diluted with ethylether, such as isoborneol, fenchyl alcohol, etc. Phorbol esters, having carcinogenesis and anti-HIV-1 effects, were not been identified. CONCLUSION: There are abundant of linoleic acid, oleic acid and eicosenoic acid in the seeds oil extracted from Chinese Croton tiglium. In contrast, the active component with carcinogenesis and anti-HIV-1 might be very rare in the samples and difficult to be obtained by ordinary separating and extracting methods.

Croton megalocarpus oil: a feasible non-edible oil source for biodiesel production.

This study presents the feasibility of converting a non-edible oil source native to the Africa region -croton megalocarpus oil to methyl esters (biodiesel) using sulfated tin oxide enhanced with SiO(2) (SO(4)(2-)/SnO(2)-SiO(2)) as super acid solid catalyst. This study was conducted using design of experiment (DoE), specifically, response surface methodology based on three-variable central composite design (CCD) with alpha (alpha)=2. The reaction parameters studied are: reaction temperature (60-180 degrees C), reaction period (1-3h) and methanol to oil ratio (1:6-1:24). Although the oil was found to contain high free fatty acid, however, yield up to 95% was obtained without any pre-treatment step with the following reaction conditions: 180 degrees C, 2h and 15:1 methanol to oil molar ratio, while keeping constant catalyst concentration and stirring speed at 3 wt.% and 350-360 rpm, respectively.

M3 muscarinic receptor- and Ca2+ influx-mediated muscle contractions induced by croton oil in isolated rabbit jejunum.

AIM OF STUDY: Croton oil is the fruit oil of Croton tiglium L., which is well known in folk medicine for the treatment of gastrointestinal (GI) diseases, including constipation, abdominal pain, peptic ulcer, and intestinal inflammation for a long period. This study was to investigate the pharmacological effect of croton oil on GI tract. MATERIALS AND METHODS: The effect of croton oil on the smooth muscle contractions was investigated in vitro using the isolated rabbit jejunum model. RESULTS: Croton oil has a biphasic action contracting and relaxing intestinal tissue. At the concentrations of 20-80 microg/mL, croton oil produced a concentration-dependent increase in the amplitude and tension of muscle contractions, whereas at high concentrations (>200 microg/mL) it decreased the contractile amplitude and had no impact on the tension. Moreover, croton oil was less effective in increasing muscle amplitude and tension than Ach, confirming that the effect of croton oil on muscle contractions is not a simply stimulatory or inhibitory action, but a unique modulatory process depending on the concentration of croton oil. In addition, croton oil concentration-dependently suppressed the frequency of muscle contractions. On the other hand, atropine (10 microM) and 4-DAMP (10 microM) produced a significant inhibition of contractions caused by croton oil, while either hexamethonium (10 microM) or methoctramine (10 microM) was inactive, implying that the regulatory effects of croton oil on GI motility are mediated via the activation of M3 muscarinic receptor. Furthermore, muscle contractions induced by croton oil were dramatically reduced by verapamil (0.1 microM) but not by NE (1 microM), suggesting that the action of croton oil on GI motility is also mediated by Ca(2+) influx through L-type Ca(2+) channel. CONCLUSIONS: The results suggest that croton oil possesses spasmogenic and spasmolytic properties and the regulatory effects of croton oil on GI motility are mediated via the activation of M3 muscarinic receptor and Ca(2+) influx through L-type Ca(2+) channel.

Synergy effects of the antibiotics gentamicin and the essential oil of Croton zehntneri.

The leaves of Croton zehntneri Pax et Hoffm (Euphorbiaceae) were subjected to hydrodistillation, and the essential oil extracted was examined with respect to antibacterial and antibiotic modifying activity by gaseous contact. The gaseous component of the oil inhibited the bacterial growth of Staphylococcus aureus and Pseudomonas aeruginosa with a MID of 0.5 and<1mg/l air, respectively. The activity of the antibiotic gentamicin was increased by 42,8% against P. aeruginosa after contact with the gaseous component, showing that this oil influences the activity of the antibiotic and may be used as an adjuvant in the antibiotic therapy of respiratory tract bacterial pathogens.

Larvicidal and nematicidal activities of the leaf essential oil of Croton regelianus.

The chemical composition of the leaf essential oil of Croton regelianus collected from wild plants growing in two different sites at Ceará State (Brazil) was analyzed by GC/MS and GC-FID. Twenty monoterpenoids, representing more than 96% of the chemical composition of the oils, were identified and quantified. The oils showed similar chemical composition but considerable variation in the levels of each constituent. Ascaridole (33.9-17.0%), p-cymene (22.3-21.6%), and camphor (13.0-3.1%) were the predominant constituents. The monoterpene ascaridole was isolated and characterized by spectroscopic data. The essential oils and the isolated compounds were tested against Aedes aegypti and Artemia sp. larvae, and the root knot nematode Meloidogyne incognita. The bioassay results show that the essential oil of C. regelianus and ascaridole were moderately active against the M. incognita, but strongly effective against both A. aegypti and Artemia sp. larvae.

The extraction, isolation and identification of the purgative component of Croton penduliflorus seed oil.

The purgative principles in Croton penduliflorus seed oil were isolated as white crystals by a bioassay-guided chromatographic separation process. The crystals were recovered in 7% w/w yield and identified (IR, 1H-NMR, GC-MS) as a mixture of palmitic, stearic and arachidic acids in approximately equimolar concentration.