Antiedematogenic and Analgesic Activities of Abietic Acid in Mice.

Exacerbated inflammatory responses to harmful stimuli can lead to significant pain, edema, and other complications that require pharmacological intervention. Abietic acid (AA) is a diterpene found as a significant constituent in pine species, and evidence has identified its biological potential. The present study aimed to evaluate abietic acid's antiedematogenic and anti-inflammatory activity in mice. Swiss mice (Mus musculus) weighing 20-30 g were treated with AA at 50, 100, and 200 mg/kg. The central nervous system (CNS) effects were evaluated using open-field and rotarod assays. The antinociceptive and anti-inflammatory screening was assessed by the acetic acid and formalin tests. The antiedematogenic activity was investigated by measuring paw edema induced by carrageenan, dextran, histamine, arachidonic acid, and prostaglandin, in addition to using a granuloma model. The oral administration of abietic acid (200 mg/Kg) showed no evidence of CNS effects. The compound also exhibited significant antiedematogenic and anti-inflammatory activities in the carrageenan and dextran models, mostly related to the inhibition of myeloperoxidase (MOP) activity and histamine action and, to a lesser extent, the inhibition of eicosanoid-dependent pathways. In the granuloma model, abietic acid's effect was less expressive than in the acute models investigated in this study. In conclusion, abietic acid has analgesic and antiedematogenic activities related to anti-inflammatory mechanisms.

Antibacterial activity and anxiolytic-like effect of Ziziphus joazeiro Mart. leaves in adult zebrafish (Danio rerio).

Ziziphus joazeiro Mart. is an endemic plant of the Caatinga that presents a great socioeconomic importance for the Northeast and Semiarid Region of Brazil. In view of this, this study aimed to evaluate the antibacterial activity and anxiolytic-like effects of Ziziphus joazeiro Mart leaves in adult zebrafish (Danio rerio). The characterization of the main classes of metabolites was performed through chemical reactions. The antibacterial and antibiotic potentiating activity was evaluated by broth microdilution assays. The 96 h acute toxicity, open field test and anxiety models test was evaluated in vivo on adult zebrafish. The results obtained in the phytochemical prospection evidenced the presence of flobabenic tannins, leucoanthocyanidins, flavonois, flavonones, catechins, alkaloids, steroids, and triterpenoids. EEFZJ did not show antibacterial activity for all microorganism tested (MIC ≥ 1024 µg/mL), but reduced the concentration required for bacterial growth inhibition in combination with gentamicin and norfloxacin against multidrug-resistant strains of S. aureus (SA10) and E. coli (EC06), exhibiting synergistic effect with these antibiotics (p<0.0001). In the tests in vivo, EEFZJ was found to be nontoxic, performing reduced locomotor activity and demonstrated an anxiolytic-like effect in adult zebrafish via GABAergic and Serotoninergic systems (5-HT1, 5-HT2A/2C and 5-HT3A/3B).

Mechanisms of Actions Involved in The Antinociceptive Effect of Estragole and its ß-Cyclodextrin Inclusion Complex in Animal Models.

(1) Background: estragole is a monoterpene found in the essential oils of several aromatic plants, which can be used for several pharmacological activities. The aim of this study was to evaluate the antinociceptive effect of estragole (Es) and its ß-cyclodextrins inclusion complex (Es/ß-CD). (2) Methods: the effects of Es and Es/ß-CD on the central nervous system (CNS) were evaluated through open field and rota-rod assays, and the antinociceptive effect in formalin models, abdominal writhing induced by acetic acid, hot plate, tail flick test and plantar mechanical hyperalgesia. (3) Results: Es and Es/ß-CD showed no alterations on the CNS evaluated parameters and the results suggested there was an antinociceptive action in the formalin, abdominal writhing, hot plate, tail flick tests and plantar mechanical hyperalgesia, proposing the involvement of the nitric oxide, glutamatergic signaling pathways, cyclic guanosine monophosphate and vanilloid pathways. (4) Conclusion: the results suggest that Es and Es/ß-CD have a promising antinociceptive potential as a possible alternative for the pharmacological treatment of pain, also showing that the encapsulation of Es in ß-cyclodextrins probably improves its pharmacological properties, since the complexation process involves much lower amounts of the compound, contributing to better bioavailability and a lower probability of adverse effect development.

Evaluation of the antifungal activity of α, ß, and δ-damascone and inclusion complexes in ß-cyclodextrin against Candida spp.

Due to the increase in fungal resistance to existing drugs, a need exists to search for new antifungals. This study aimed to evaluate the antifungal activity of α, ß, and δ-damascone and inclusion complexes with ß-cyclodextrin against different Candida spp. The inclusion complex of ß-damascone was prepared by the co-evaporation method using three molar proportions (1:1; 2:1; 3:1 (ßDA-ßCD)) and analyzed using Fourier transform infrared spectroscopy (FTIR). Standard Candida albicans (CA INCQS 40,006), Candida krusei (CK INCQS 40,095), and Candida tropicalis (CT INCQS 40,042) strains were used to evaluate antifungal activity. The substances were tested individually or in association with fluconazole (FCZ). The IC50 and cell viability curve constructions were performed using the microdilution method. The minimum fungicidal concentration (MFC) was determined by the subculture method in a solid medium. The α, ß, and δ-DA isolated or in combination with fluconazole (FCZ) showed significant antifungal activity. ß-damascone showed effective complexation in the three molar proportions assayed; however, none of the inclusion complexes was demonstrated clinically significant effects against the fungal tested. Then, all compounds have shown promising antifungal activities; however, in vivo assays are necessary to have therapeutical application in the future.

UPLC-MS-ESI-QTOF Analysis and Antifungal Activity of Aqueous Extracts of Spondias tuberosa.

This study aimed to identify the chemical composition of the Spondias tuberosa aqueous leaf and root extracts (EALST and EARST) and to evaluate their effect, comparatively, against opportunistic pathogenic fungi. Ultra-Performance Liquid Chromatography Coupled to a Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF) was employed for chemical analysis. Candida albicans and C. tropicalis standard strains and clinical isolates were used (CA INCQS 40006, CT INCQS 40042, CA URM 5974, and CT URM 4262). The 50% Inhibitory Concentration for the fungal population (IC50) was determined for both the intrinsic action of the extracts and the extract/fluconazole (FCZ) associations. The determination of the Minimum Fungicidal Concentration (MFC) and the verification of effects over fungal morphological transitions were performed by subculture in Petri dishes and humid chambers, respectively, both based on micro-dilution. UPLC-MS-ESI-QTOF analysis revealed the presence of phenolic and flavonoid compounds. The association of the extracts with fluconazole, resulted in IC50 values from 2.62 µg/mL to 308.96 µg/mL. The MFC of the extracts was ≥16,384 µg/mL for all tested strains, while fluconazole obtained an MFC of 8192 µg/mL against C. albicans strains. A reduction in MFC against CA URM 5974 (EALST: 2048 µg/mL and EARST: 1024 µg/mL) occurred in the extract/fluconazole association.

Chemical Constituents and Biological Activities of Croton heliotropiifolius Kunth.

Croton heliotropiifolius Kunth (Euphorbiaceae), whose occurrence has already been registered in the most varied Brazilian biomes, is commonly found in the Chapada do Araripe, Ceará. The species is traditionally used to treat fungal, parasitic, and degenerative diseases. This study investigated the chemical composition and pharmacological potential (antioxidant, antifungal, antiparasitic, and cytotoxic) of an aqueous extract obtained from the roots of C. heliotropiifolius. Following a qualitative phytochemical screening, the chemical constituents were identified by ultra-efficiency liquid chromatography coupled witha quadrupole/time-of-flight system (UPLC-QTOF). The antioxidant potential was verified by thin-layer chromatography (TLC). The direct and combined antifungal activity of the extract against opportunistic Candida strains was investigated using the microdilution method. The minimal fungicidal concentration (MFC) was determined by subculture, while the modulation of the morphological transition (fungal virulence) was evaluated by light microscopy. The in vitro antiparasitic activity was analyzed using epimastigotes of Trypanosoma cruzi and promastigotes of Leishmania braziliensis and Leishmania infantum, while cytotoxicity was determined in cultures of mouse fibroblasts. The phytochemical analysis identified the presence of acids, terpenes, flavonoids, lignans, and alkaloids. Among these constituents, the presence of polar and non-polar phenolic compounds with known antioxidant action was highlighted. While the extract showed clinically ineffective antifungal effects, it could enhance the effectiveness of fluconazole, in addition to inhibiting the morphological transition associated with increased virulence in Candida strains. Although the extract showed low cytotoxicity against fibroblasts, it also had weak antiparasitic effects. In conclusion, Croton heliotropiifolius is a source of natural products with antifungal and antioxidant potential.

Evaluation of antibacterial activity and reversal of the NorA and MepA efflux pump of estragole against Staphylococcus aureus bacteria.

The antibacterial activity of the monoterpene estragole was evaluated against two strains of bacteria with an efflux pump mechanism, which are Staphylococcus aureus 1199B and S. aureus K2068, which have a NorA and MepA pump, respectively. For that, the methodology proposed by CLSI with modifications was followed, and to evaluate the reversal of the efflux pump, subinhibitory concentrations (MIC/8) of estragole and standard pump inhibitors, CCCP and Chlorpromazine were used and it was verified whether they managed to modulate the action of Norfloxacin, Ciprofloxacin and Ethidium Bromide, an indicator of an efflux pump. It was observed that estragole positively modulated norfloxacin and ethidium bromide against the strain of S. aureus 1199B and that it also managed to reduce the MIC of ethidium bromide against the strain of S. aureus K2068. In the non-clinical acute toxicity tests with estragole, the animals treated with the dose of 625 mg/kg/v.o. showed no clinical signs of toxicity, according to the parameters evaluated. These results are promising, since it places estragole as a possible inhibitor of the efflux pump, thus managing to inhibit this mechanism of action in the strains tested.

Graviola Fruit Bar Added Acerola By-Product Extract Protects Against Inflammation and Nociception in Adult Zebrafish (Danio rerio).

Studies involving foods associated with pain reversal and anti-inflammatory effects using zebrafish are rarely reported in the literature. This study aimed to evaluate the effect of graviola (Annona muricata L.) fruit bar (GFB) and GFB added with acerola (Malpighia glabra L) seed extract (ASE) on acute nociception and abdominal inflammation in adult zebrafish (Danio rerio). Acute nociception was induced by formalin, capsaicin, cinnamaldehyde, acidic saline, glutamate (cutaneous models), and hypertonic saline (corneal model), and inflammation was induced by carrageenan. Both GFB and ASE exhibited antinociceptive effect modulated by the nitrergic system, guanylate cyclase, and transient receptor potential ankyrin 1 and acid-sensing ion channels. The antinociceptive effect of GFB also appears to be modulated by the opioid system and glutamatergic receptors (N-methyl-D-aspartate receptor). Only ASE presented corneal antinociceptive effect. Both samples showed anti-inflammatory effect, being more significant the effect of GFB. The addition of acerola by-product extract in GFB results in a product with greater biological potential.

Orofacial antinociceptive effect of sulphated polysaccharide from the marine algae Hypnea pseudomusciformis in rodents.

This study aimed to evaluate the antinociceptive effect of sulphated polysaccharide from the marine algae Hypnea pseudomusciformis (PLS) using rodent models of orofacial pain. Acute pain was induced by formalin, capsaicin, cinnamaldehyde, acidified saline or glutamate (cutaneous modes) and hypertonic saline (corneal model). In one experiment, animals were pretreated with ruthenium red, glibenclamide, naloxone, L-NAME, methylene blue or ketamine to investigate the mechanism of antinociception. In another experiment, animals pretreated with PLS or saline were submitted to the temporomandibular joint formalin test. In yet another, animals were submitted to craniofacial pain induced by mustard oil. Motor activity was evaluated with the open-field test. Cytotoxicity and antioxidant activities were also assessed. Pre-treatment with PLS significantly reduced nociceptive behavior associated with acute pain. Antinociception was effectively reduced, but not inhibited, by ruthenium red and ketamine. L-NAME and glibenclamide enhanced the PLS effect. PLS antinociception was resistant to methylene blue, naloxone and heating. PLS presented no cytotoxicity or antioxidant properties. Our results confirm the potential pharmacological relevance of PLS as an inhibitor of orofacial nociception in acute pain probably mediated by glutamatergic, nitrergic, TRPs and K + ATP pathways.

Adult Zebrafish (Danio rerio) As a Model for the Study of Corneal Antinociceptive Compounds.

Zebrafish is an excellent model that can be utilized as an adjunct to current rodent models for studies of eye diseases because the anatomy and ultrastructural characterization of its cornea show much similarity with the human cornea. Therefore, we developed a behavioral model of corneal nociception using the adult zebrafish (Danio rerio). We analyzed the nociceptive effect of hypertonic saline (0.15-5.0 M sodium chloride [NaCl]) applied to the surface of the right or left cornea, on the animals' gender and locomotor activity through the open-field test. The behavioral model of corneal nociception was characterized by the antinociceptive effect of morphine (8.0 or 16 mg/kg; intraperitoneally [i.p.]), an opioid analgesic, and capsazepine, an antagonist of transient receptor potential vanilloid type 1 channels. We also tested whether the corneal antinociceptive effect of morphine could be modulated by naloxone, an opioid antagonist. Finally, we used the light and dark test to assess the anxiolytic effect of hypertonic saline (5.0 M NaCl; 5 µL) applied to the right or left cornea of the animals. As a result, hypertonic saline significantly increased (p < 0.01 vs. control) the corneal nociceptive behavior of adult zebrafish (D. rerio). Morphine significantly inhibited (p < 0.01 vs. 5.0 M NaCl) the hypertonic saline-induced corneal nociception and this effect was blocked by naloxone. Capsazepine (20 mg/kg; i.p.) significantly inhibited (p < 0.05 vs. control) the corneal nociception induced by hypertonic saline. Hypertonic saline, applied to the surface of the right or left cornea of the animals, induced nociception and did not cause a presumptive anxiolytic effect. Gender and site of application did not affect the profile of response to hypertonic saline. The results suggest that the adult zebrafish can also be used as a behavioral model of corneal nociception, with the advantages of significant homology with the human genome and low cost.

Adult Zebrafish (Danio rerio): An Alternative Behavioral Model of Formalin-Induced Nociception.

The zebrafish (Danio rerio) has been proposed as a low-cost and simple alternative to the use of higher vertebrates in laboratory research on novel compounds with antinociceptive potential. In this study, we tested adult zebrafish (Danio rerio) as an alternative behavioral model of formalin-induced nociception. We evaluated the nociceptive effect of 0.1% formalin (3 or 5 µL; intramuscularly [i.m.]), applied into the tail or lips, on locomotor activity, using as parameter the number of times the fish crossed the lines between the quadrants of a glass Petri dish during the neurogenic stage (0-5 min) and the inflammatory stage (15-30 min). The behavioral model was validated by testing the antinociceptive effect of morphine and indomethacin (standard analgesic drugs used in the formalin test of rodents). We also tested whether the effect of morphine could be modulated by naloxone, an opioid antagonist. The effect of morphine and indomethacin on zebrafish locomotor behavior was evaluated with the open field test. The white/black test was used to rule out the anxiolytic effect of 0.1% formalin injected into the tail on adult zebrafish. Formalin (0.1%; 3 and 5 µL injected into the tail) increased significantly the nociceptive behavior of the adult zebrafish in both stages (p < 0.001 vs. control). Morphine and indomethacin (both 0.2 mg/mL; 20 µL; intraperitoneally [i.p.]) significantly inhibited nociception induced with formalin (5 µL injected i.m. into the tail) in both stages (p < 0.001). Naloxone blocked the antinociceptive effect of morphine. No influence on locomotion was observed. Locally administered formalin (injected into the tail) induced nociception, but not anxiety. The results suggest that the adult zebrafish behavioral model is a feasible alternative to more conventional laboratory models used in research on novel compounds with antinociceptive potential.