Investigation of the anti-inflammatory effects of stigmasterol in mice: insight into its mechanism of action.

Stigmasterol is a phytosterol that presents pharmacologic properties. However, its anti-inflammatory mechanism and antinociceptive effect are not yet elucidated. Thus, the present study aimed to investigate the anti-inflammatory and antinociceptive activities of stigmasterol and its mechanism of action in mice. The antinociceptive activity was assessed by the acetic acid-induced writhing test, formalin test, and hot plate test. The anti-inflammatory activity was investigated by carrageenan-induced peritonitis and paw edema induced by arachidonic acid. The involvement of glucocorticoid receptors in the mechanism of stigmasterol anti-inflammatory action was investigated by molecular docking, also by pretreating mice with RU-486 (glucocorticoid receptor antagonist) in the acetic acid-induced writhing test. Mice motor coordination was evaluated by the rota-rod test and the locomotor activity by the open field test. The lowest effective dose of stigmasterol was standardized at 10 mg/kg (p.o.). It prevented abdominal writhes and paw licking, but it did not increase the latency time in the hot plate test, suggesting that stigmasterol does not show an antinociceptive effect in response to a thermal stimulus. Stigmasterol decreased leukocyte infiltration in peritonitis assay and reduced paw edema elicited by arachidonic acid. Molecular docking suggested that stigmasterol interacts with the glucocorticoid receptor. Also, RU-486 prevented the effect of stigmasterol in the acetic-acid abdominal writhing test, which might indicate the contribution of glucocorticoid receptors in the mechanism of stigmasterol action. Stigmasterol reduced the number of crossings but did not impair mice's motor coordination. Our results show that stigmasterol presents anti-inflammatory effects probably mediated by glucocorticoid receptors.

Fatty acid profile of pecan nut oils obtained from pressurized n-butane and cold pressing compared with commercial oils.

This short note compares the chemical profile of pecan nut oil samples obtained from pressurized n-butane and cold pressing with two commercial oils. The conventional cold pressing technique yielded 58.9 wt%, while pressurized n-butane yielded from 53 to 65 wt%, being the highest yield at 55 °C, and pressure of 40 bar. The n-butane behaves nearly like a piston fluid within the experimental conditions used. The results showed that the extraction variables had a slight influence on the fatty acid composition of the samples. Extraction with n-butane thus showed to be a promising alternative technique to conventional extraction methods, as very mild operating conditions and eco-friendly solvent can be used to provide good results without any residues in the final product.

Phytochemical profile, antioxidant and antimicrobial activity of extracts obtained from erva-mate (Ilex paraguariensis) fruit using compressed propane and supercritical CO2.

Traditionally, Ilex paraguariensis leaves are consumed in tea form or as typical drinks like mate and terere, while the fruits are discarded processing and has no commercial value. The aim of this work to evaluate phytochemical properties, total phenolic compounds, antioxidant and antimicrobial activity of extracts of Ilex paraguariensis fruits obtained from supercritical CO2 and compressed propane extraction. The extraction with compressed propane yielded 2.72 wt%, whereas with supercritical CO2 1.51 wt% was obtained. The compound extracted in larger amount by the two extraction solvents was caffeine, 163.28 and 54.17 mg/g by supercritical CO2 and pressurized propane, respectively. The antioxidant activity was more pronounced for the supercritical CO2 extract, with no difference found in terms of minimum inhibitory concentration for Staphylococcus aureus for the two extracts and better results observed for Escherichia coli when using supercritical CO2.

Extraction, chemical characterization and antioxidant activity of Litchi chinensis Sonn. and Avena sativa L. seeds extracts obtained from pressurized n-butane.

The extraction of litchi (Litchi chinensis Sonn.) and oat (Avena sativa L.) seeds were investigated using n-butane as pressurized solvent by evaluating the effect of pressure in the range of 7-100 bar and temperature from 25 to 70 °C on the extract yield and chemical composition together with the antioxidant activity of the extracts obtained. It was experimentally observed extraction yields for both seeds up to ~3.5 wt%, with a total phenolic content around 126.4 mg GAE/100 g of extract, and an antioxidant activity up to 78.36%. Oat seeds extract presented higher values of these parameters evaluated compared to litchi extract. Based on the results found, it seems that n-butane may be a promising solvent to conventional extraction methods, as mild operating conditions and eco-friendly solvent can be used to provide good results without any residues in the final product.

Antidepressant-like effect of Campomanesia xanthocarpa seeds in mice: Involvement of the monoaminergic system.

Background and aim: Campomanesia xanthocarpa Berg. (Myrtaceae) present several pharmacological actions, but there are no reports on its antidepressant-like potential. This study investigated the antidepressant-like effect and mechanism of action of Campomanesia xanthocarpa seeds extract obtained from supercritical CO2 (40 °C, 250 bar). Experimental procedure: Mice were orally treated with the extract 1 h before the TST. To investigate the involvement of the monoaminergic system in the antidepressant-like activity of the extract, pharmacological antagonists were administered prior to the acute oral administration of the extract (60 mg/kg). Also, the interaction of the extract with antidepressants was assessed in the tail suspension test (TST). The in vitro inhibitory potential of C. xanthocarpa seeds extract towards MAO A and MAO B enzymes was tested in vitro. Results and conclusion: Animals treated with Campomanesia xanthocarpa seeds extract showed a significant reduction in the immobility time in the TST. Mice pretreatment with SCH23390, sulpiride, prazosin, yohimbine, and p-chlorophenylalanine prevented the anti-immobility effect of the extract in the TST. The combined administration of sub-effective doses of the extract with imipramine, bupropion and fluoxetine significantly reduced mice immobility time in the TST. The extract showed MAO A inhibitory activity (IC50 = 151.10 ± 5.75 µg/mL), which was greater than that toward MAO B (IC50 > 400 µg/mL).The extract of Campomanesia xanthocarpa seeds obtained by supercritical CO2 shows antidepressant-like activity, which relies on the activation of the monoaminergic neurotransmission (serotoninergic, dopaminergic and noradrenergic), suggesting that this species might represent a resource for developing new antidepressants.

Antinociceptive effect and mechanism of supercritical carbon dioxide extract of Aloysia gratissima leaves in mice.

BACKGROUND: A. gratissima is a shrub used in folk medicine as analgesic and sedative. However, studies on its antinociceptive activity are scarce. This research aimed to evaluate the antinociceptive effect of a supercritical carbon dioxide (SCCO2) extract of A. gratissima leaves (EAG) in mice. METHODS: A. gratissima leaves were subjected to extraction with supercritical CO2 (60 °C, 200 bar). The chemical composition of EAG was determined by gas chromatography-mass spectrometry (GC-MS). The antinociceptive profile of the extract (1, 10 and 30 mg/kg, p.o.) was established using acetic acid-induced abdominal contraction tests and formalin-induced paw-licking tests. The open field and rota-rod tests were used to evaluate a possible interference of EAG on mice motor performance. The contribution of the opioid system and adenosine triphosphate (ATP) sensitive K+ channels in the mechanism(s) of EAG action was evaluated by specific receptor blockers. EAG's acute toxicity was investigated using OECD 423 guideline. RESULTS: The GC-MS revealed the presence of sesquiterpenes (guaiol and pinocamphone) in the EAG. Doses of 10 mg/kg and 30 mg/kg significantly reduced the number of abdominal writhes and paw licking time in mice in the formalin test. The EAG did not affect the locomotor activity and motor coordination of the mice. The antinociceptive effect of the EAG was prevented by glibenclamide in the mice formalin test, unlike naloxone pre-treatment. The acute administration of EAG caused no mortality. CONCLUSION: A. gratissima leaves possess antinociceptive effect, mediated by K+ channels sensitive to ATP.

Anti-Inflammatory Effects of Campomanesia xanthocarpa Seed Extract Obtained from Supercritical CO2.

Campomanesia xanthocarpa is a plant species traditionally used in the treatment of diabetes, fever, hypercholesterolemia, obesity, and urinary tract diseases. The anti-inflammatory effects of C. xanthocarpa leaves in mice were already known. Nevertheless, studies on the anti-inflammatory activity of its seeds are still lacking. The aim of this study was to investigate the anti-inflammatory activity and acute toxicity of C. xanthocarpa seed extract, obtained from supercritical CO2 extraction (SCCO2) at 40°C and 250 bar, in mice. GC/MS analysis revealed that ß-caryophyllene is the major compound present in the C. xanthocarpa SCCO2 extract. The extract (60 mg/kg, p.o.) significantly reduced the nociceptive behavior in the second phase of the formalin test and prevented the paw oedema induced by carrageenan up to 6 h after carrageenan injection. The extract (0.1-1 µg/mL) inhibited neutrophils migration induced by LPS from E. coli in vitro. This antichemostatic effect was comparable to the effect of indomethacin. Acute administration (2000 mg/kg, p.o.) of C. xanthocarpa SCCO2 extract caused no mice mortality, demonstrating that the extract is devoid of acute toxicity. These data suggest that C. xanthocarpa seeds present anti-inflammatory activity and represent a source of anti-inflammatory compounds.

Antinociceptive and anti-inflammatory activities of Philodendron bipinnatifidum Schott ex Endl (Araceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Popular medicine use stems of Philodendron bipinnatifidum (Araceae) in inflammation cases, such as in erysipelas, as well as orchitis and rheumatism treatment. The present study, conducted for the first time in literature, investigate the antinociceptive and anti-inflammatory activities of P. bipinnatifidum stems ethyl acetate extract (EPB). MATERIALS AND METHODS: GC/MS and HPLC analysis were performed for EPB extract. We used EPB at 250, 375 and 500 mg/kg (oral route, p.o.) in male Swiss mice. The antinociceptive activity of the plant extract assessed by acetic acid induced writhing and formalin tests. To investigate the possible participation of opioid system in EPB-mediated effects, we previously administered naloxone to the mice. Anti-inflammatory activity was evaluated using carrageenan-induced paw oedema. The open-field test aimed to investigate the possible EPB effects on the locomotor and exploratory activities. To assess the protective role of EPB on carrageenan-induced oxidative stress, the levels of NPSH, TBARS, as well as SOD and CAT activities were evaluated in blood and paw tissue. The acute toxicity of the EPB was investigated using OECD 423 guideline. RESULTS: The EPB chemical analysis by GC/MS and HPLC revealed the presence of flavonoids (luteolin and quercetin) and phytosterols (ß-sitosterol and stigmasterol). The oral treatment with the EPB inhibited mice abdominal writhings (P < 0.01) at 375 and 500 mg/kg, and reduced the formalin effect at the first-phase (500 mg/kg, P < 0.05) and also at the second-phase (500 mg/kg, P < 0.001) of the test. EPB (375 and 500 mg/kg) did not alter spontaneous locomotion in open field test, however the number of fecal bolus was significantly lower for the EPB group at 500 mg/kg when compared to the vehicle group (P < 0.05). The pretreatment with naloxone caused significant inhibition of antinociceptive activity induced by EPB in the formalin test, revealing the possible involvement of opioid receptors. EPB extract administered at 500 mg/kg (p.o.) prevented carrageenan-induced paw oedema (P < 0.05 and 0.01) until 6 h after carragenan injection. Evaluation of TBARS and NPSH levels, SOD and CAT activities in the blood and paw tissue of animals submitted to the carrageenan assay suggested that the anti-inflammatory effect of EPB may be linked to oxidative stress inhibition. The acute administration of the EPB (2000 mg/kg, p.o.) caused no mortality, demonstrating low toxicity. CONCLUSIONS: The extract of P. bipinnatifidum displays antinociceptive and anti-inflammatory activities, causing no toxicological effects. The pharmacological activity of this vegetal species may be related to the presence of flavonoids and phytosterols. Our results support the ethnomedical use of this vegetal species as analgesic and anti-inflammatory agent.

Synthesis of Ag@Fe2O3 nanocomposite based on O-carboxymethylchitosan with antimicrobial activity.

In this paper, nano-hybrid particles of Ag@Fe2O3 based on O-carboxymethylchitosan were successfully synthesized using different reducing agents (NaBH4, sucrose) and without reducing agent. The smallest silver nanoparticles were those prepared without reducing agent (∼5±3nm). The average size of silver particles prepared with NaBH4 is around 5-15nm, and for samples prepared with sucrose, the average particle size is 10-25nm. The magnetization curves are roughly reversible, indicating that γ-Fe2O3 nanoparticles transit to a superparamagnetic state. Nanocomposites subjected to antimicrobial tests showed great antimicrobial activity against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, and good activity against the yeast Candida albicans and resistant strains of Staphylococcus aureus. The antibacterial behavior as a function of time was investigated in microbial growth kinetics, and the best nanocomposite was the one without reducing agent, which completely inhibited microbial growth for 48h.