Paulo César Ghedini

Plurality of anxiety and depression alteration mechanism by oleanolic acid.

Our study sought to evaluate the anxiolytic and antidepressant activities of oleanolic acid as well as the neural mechanisms involved. Animal models such as barbiturate sleep-induction, light–dark box, elevated plus maze, forced swimming test, tail suspension test and open field test were conducted. Male Albino Swiss mice were treated orally with vehicle 10 mL/kg, fluoxetine 20 mg/kg, imipramine 15 mg/kg, diazepam 1 mg/kg or oleanolic acid 5–40 mg/kg. Pretreatment (intraperitoneal) of animals with pentylenetetrazole (PTZ) 20 mg/kg, 1-(2-methoxyphenyl)-4-[4- (2-phthalimido) butyl]piperazine hydrobromide (NAN-190) 0.5 mg/kg, p-chlorophenylalanine methyl ester (PCPA) 100 mg/kg or α-methyl-p-tyrosine (AMPT) 100 mg/kg, WAY100635 (WAY) 0.3 mg/kg, prazosin (PRAZ) 1 mg/kg, yohimbine 2 mg/kg as well as monoamine oxidase assay and hippocampal brain-derived neurotrophic factor (BDNF) quantification were carried out. Oleanolic acid potentiated the hypnotic effect of barbiturate and demonstrated an anxiolytic effect in both the light–dark box and elevated plus maze. This effect was not reversed by PTZ. Acute and/or chronic oral treatment of mice with oleanolic acid (5−20 mg/kg) elicited an antidepressant effect in the forced swimming test and the tail suspension test without interfering with the locomotor activity. The antidepressant effect of oleanolic acid was attenuated by NAN-190, AMPT, PCPA, WAY and PRAZ. Although monoamine oxidase activity remained unaltered by oleanolic acid, chronic administration of oleanolic acid augmented hippocampal BDNF level. These findings demonstrate multiple mechanisms of the anxiolytic and antidepressant effect of oleanolic acid.

Mechanisms involved in the gastroprotective activity of Celtis iguanaea (Jacq.) Sargent on gastric lesions in mice.

ETHNOPHARMACOLOGICAL RELEVANCE Celtis iguanaea (Canabaceae) is popularly known as esporão-de-galo, stands out among the medicinal plants used for treatment of gastric ulcers. In Brazil, the leaves they are used traditionally in infusion forms as an analgesic, antiasthmatic, digestive and diuretic. AIM OF THE STUDY The present study was aimed to investigate the antiulcer mechanisms of hexane extract Celtis iguanaea leaves (HE) in several induced-gastric ulcer and characterize its chemical composition. MATERIALS AND METHODS The HE was obtained by exhaustive extraction in Soxhlet apparatus. The chemical characterization of HE was performed by Electrospray Fourier transform ion cyclotron mass spectrometry (ESI FT-ICR MS) analysis. Mice were used for the evaluation of the gastroprotective activity. HE was analyzed in the HCl/ethanol, hypothermic restraint stress ulcer and acetic acid. In the investigation of the gastroprotective mechanisms of HE, were performed the amount of adhered gastric mucus, participation of the α2-adrenoceptor, nitric oxide (NO) and prostaglandins (PGs) using the HCl/ethanol-induced gastric mucosa lesion model. RESULTS ESI FT-ICR MS analysis of HE suggest the presence of compounds as lipids, sterol lipids, steroids glycosides and polyphenol glycosides. The oral administration of HE at doses of 100 mg/kg or 200 mg/kg was able to protect the gastric mucosa against HCl/ethanol (10 mL/kg p.o.), and HE at dose of 100mg/kg protected against hypothermic-restraint stress and acetic -induced gastric lesions. The pretreatment with Yoimbine (2mg/kg, s.c.), an antagonist α2-adrenergic, L-NAME (20mg/kg, s.c.), an inhibitor of nitric oxide synthesis or indomethacin (10mg/kg, s.c.), an inhibitor of prostaglandin production, reversed the gastroprotective activity of HE (100mg/kg, p.o.). CONCLUSIONS Our results suggest that the Celtis iguanaea HE exhibits gastroprotective activity in different gastric ulcer models. The mechanism of gastroprotective effect of Celtis iguanaea HE suggests the participation of mucus as well as the involvement of α2-adrenergic receptors, NO and prostaglandins. The hydroxyl-linolenic acid, linoleic acids and conjugated oxo-linoleic acids are among the phytoconstituents that were identified in the Celtis iguanaea HE.

Involvement of 5-HT1A in the anxiolytic-like effect of dichloromethane fraction of Pimenta pseudocaryophyllus

ETHNOPHARMACOLOGICAL RELEVANCE Medicinal applications of Pimenta pseudocaryophyllus infusion as a diuretic and aphrodisiac agent as well as tranquilizer in the form of tea for the treatment of emotional tension in Brazilian folk medicine has been in practice since time immemorial. Despite its popular therapeutic acceptance and claims, there are scanty scientific reports to corroborate its central biological activities. AIM To characterize anxiolytic-like effect of the dichloromethane fraction (DF) obtained from ethanolic leaf extract of the Pimenta pseudocaryophyllus and identify mechanisms of action involved while seeking to support its popular use as a soothing agent. MATERIAL AND METHODS Mice (25-35 g) were treated orally with DF obtained from ethanolic leaf extract of Pimenta pseudocaryophyllus and were submitted to light-dark box (LDB) and elevated plus maze (EPM) tests. Different groups of mice were treated with flumazenil and NAN-190 to identify mechanisms of action involved in the anxiolytic-like effect of DF. RESULTS Treatment with DF increased number of transitions and time spent in the light compartment of the LDB while the time spent and numbers of entries in the open arm of the LCE were significantly increased. Pre-treatment of the animal with flumazenil (2 mg/kg, i.p.--competitive antagonist of benzodiazepine site of GABA(A) receptor) did not block this effect, thereby excluding participation of benzodiazepine site of the GABA(A) receptor. However, anxiolytic-like effect of DF was reversed by pre-treatment with NAN-190 (0.5 mg/kg, i.p.--an antagonist of the 5-HT(1A) receptor) thereby suggesting involvement of 5-HT(1A) receptor. The thin layer chromatography and high-performance liquid chromatography analysis indicated the predominance of (E)-methyl isoeugenol and oleanolic acid in DF. CONCLUSION These results support the popular use of Pimenta pseudocaryophyllus as a calming agent and suggest the involvement of 5-HT(1A) receptor.

Electroanalytical tools for antioxidant evaluation of red fruits dry extracts

Red fruits are rich sources of antioxidant compounds with recognized health benefits. Since they are perishable, dried extracts emerge as more durable products and their quality control must include antioxidant capacity assays. In this study, the redox behavior of commercial dried products obtained from camu-camu, açai, acerola and cranberry red fruits was evaluated by electroanalytical approaches. The antioxidant potential was determined by 2,2-diphenyl-1-picrylhydrazyl free radical assay and the electrochemical index concept. The total phenol content was estimated by using a laccase based biosensor. A significant correlation was found between all methods and literature data. The voltammetric profile (cyclic, differential and square wave) obtained for each type of dried extract showed distinguishable features that were correlated with their main major markers, being also useful for identification purposes. The electrochemical methods were cheaper and more practical for evaluation of antioxidant properties and total phenol content in dried powders obtained from different red fruits.

Preliminary studies of gastroprotective effect of Celtis iguanaea (Jacq.) Sargent leaves (Ulmaceae)

Antiulcerogenic activity of crude ethanolic extract of Celtis iguanaea leaves (CEE) was observed with experimental models such as ethanol, indomethacin, stress and pyloric ligation-induced gastric ulcers. Results obtained from indomethacin-induced ulcer showed the hexane fraction (HF) as the active fraction of CEE. This fraction inhibits the gastric acid secretion, increasing the gastric pH, decreasing the gastric acidity and total gastric contents. Neither the CEE nor the HF alters intestinal motility, thereby excluding a cholinergic antagonist mechanism. Further studies need to be conducted with HF in order to elucidate the active principle and the pharmacological mechanism involved.

Antidepressive-Like Property of Dichloromethane Fraction of Pimenta pseudocaryophyllus and Relevance of Monoamine Metabolic Enzymes

Pimenta pseudocaryophyllus popularly referred to as craveiro is considered as a calming agent in different local preparations. The present study attempted to examine antidepressant-like effect of dichloromethane fraction (DF) and role of monoamine oxidase (MAO), tryptophan, and tyrosine hydroxylase. Based on the research focus, tail suspension (TS), forced swimming (FS), and open field (OF) tests were conducted after oral administration of DF (125, 250, or 500 mg/Kg). Ex vivo assay of MAO was also conducted to evaluate inhibitory effect of DF (250 mg/Kg). Administration of DF elicits antidepressant-like response in the TS and FS. However, DF 500 mg/Kg did not alter mice performance in these models. The data obtained in the OF showed a reduction in total crossing and rearing activity; these effects suggest motor interference in TS and FS performance. Mice pretreatment with p-chlorophenylalanine methyl ester (PCPA) (100 mg/kg, i.p.—serotonin biosynthesis inhibitor) for 4 consecutive days or acute administration of α-methyl-p-tyrosine (AMPT) (100 mg/kg, i.p.—catecholamine synthesis inhibitor) blocked anti-immobility effect of DF in the FS. In ex vivo assay of MAO, DF did not inhibit catabolic activity of MAO. Our findings support antidepressant-like activity of DF and suggest an effect that depends on monoamine biosynthesis.

Endothelium-Dependent Vasorelaxant Effect of Butanolic Fraction from Caryocar brasiliense Camb. Leaves in Rat Thoracic Aorta

Caryocar brasiliense Camb. “pequi” is a native plant from the Cerrado region of Brazil that contains bioactive components reported to be antioxidant agents. Previous work has demonstrated that dietary supplementation with pequi decreased the arterial pressure of volunteer athletes. We found that the crude hydroalcoholic extract (CHE) of C. brasiliense leaves relaxed, in a concentration-dependent manner, rat aortic rings precontracted with phenylephrine, and that the butanolic fraction (BF) produced an effect similar to that of the CHE. Aortic relaxation induced by BF was abolished by endothelium removal, by incubation of the nitric oxide synthase inhibitor L-NAME, or the soluble guanylatecyclase inhibitor ODQ. However, incubation with atropine and pyrilamine had no effect on the BF-induced vasorelaxation. Moreover, this effect was not inhibited by indomethacin and tetraethylammonium. The concentration-response curve to calcium in denuded-endothelium rings was not modified after incubation with BF, and the vasorelaxation by BF in endothelium-intact rings precontracted with KCl was abolished after incubation with L-NAME. In addition, administration of BF in anesthetized rats resulted in a reversible hypotension. The results reveal that C. brasiliense possesses both in vivo and in vitro activities and that the vascular effect of BF involves stimulation of the nitric oxide/cyclic GMP pathway.

The vasorelaxant effect of gallic acid involves endothelium-dependent and -independent mechanisms.

The mechanisms of action involved in the vasorelaxant effect of gallic acid (GA) were examined in the isolated rat thoracic aorta. GA exerted a relaxant effect in the highest concentrations (0.4-10mM) in both endothelium-intact and endothelium-denuded aortic rings. Pre-incubation with L-NAME, ODQ, calmidazolium, TEA, 4-aminopyridine, and barium chloride significantly reduced the pEC50 values. Moreover, this effect was not modified by indomethacin, wortmannin, PP2, glibenclamide, or paxillin. Pre-incubation of GA (1, 3, and 10mM) in a Ca(2+)-free Krebs solution attenuated CaCl2-induced contractions and blocked BAY K8644-induced vascular contractions, but it did not inhibit a contraction induced by the release of Ca(2+) from the sarcoplasmatic reticulum stores. In addition, a Western blot analysis showed that GA induces phosphorylation of eNOS in rat thoracic aorta. These results suggest that GA induces relaxation in rat aortic rings through an endothelium-dependent pathway, resulting in eNOS phosphorylation and opening potassium channels. Additionally, the relaxant effect by an endothelium-independent pathway involves the blockade of the Ca(2+) influx via L-type Ca(2+) channels.

Anti-ulcerogenic and antisecretory effects of Celtis iguanaea (Jacq.) Sargent hexane leaf extract

The Celtis iguanaea (Jacq.) Sargent (Cannabaceae) is one of the native species of the Cerrado region of Brazil widely used in folk medicine to treat dyspepsia. The objective of the present study was to evaluate the gastroprotective effect of the Celtis iguanaea (Jacq.) Sargent (HE) hexane leaf extract in the lesion and gastric secretion models.Antiulcerogenic activity of the Celtis iguanaea (HE) hexane leaf extract was observed with the experimental models, such as indomethacin and pyloric ligation-induced gastric ulcers. In order to evaluate the antisecretory activity of this extract, isolated Rana catesbeiana mucosa and pyloric ligation in mice were used. The HE treatment reduced the lesion index of indomethacin and pyloric ligation-induced ulcer. This extract also reduced the gastric acid secretion and total acidity (increasing the gastric pH) in mice. The secretion of H+ was reduced in the basal values (15.58 ± 1.99 µEq H+/g/15 min) when isolated Rana catesbeiana mucosa was incubated with HE. Intraduodenal administration of HE reduced the gastric secretion produced by bethanecol or histamine. The antiulcerogenic and antisecretory efficacy of HE in this study suggest anticholinergic and antihistaminergic mechanism or interruption of intracellular events that are linked to acid secretion.

Anxiolytic-like effect of 2-(4-((1-phenyl-1H -pyrazol-4-yl)methyl)piperazin-1-yl)ethan-1-ol is mediated through the benzodiazepine and nicotinic pathways

In this study, we proposed the design, synthesis of a new compound 2‐(4‐((1‐phenyl‐1H‐pyrazol‐4‐yl)methyl)piperazin‐1‐yl)ethan‐1‐ol (LQFM032), and pharmacological evaluation of its anxiolytic‐like effect. This new compound was subjected to pharmacological screening referred to as Irwin test, prior to sodium pentobarbital‐induced sleep, open‐field and wire tests. The anxiolytic‐like effect of this compound was evaluated using elevated plus maze and light–dark box tests. In addition, the mnemonic activity was evaluated through step‐down test. In sodium pentobarbital‐induced sleep test, LQFM032 decreased latency and increased duration of sleep. In the open‐field test, LQFM032 altered behavioral parameter, that suggested anxiolytic‐like activity, as increased in crossings and time spent at the center of open field. In the plus maze test and light–dark box test, the LQFM032 showed anxiolytic‐like activity, increased entries and time spent on open arms, and increased in number of transitions and time spent on light area, respectively. Those effects was antagonized by flumazenil but not with 1‐(2‐Methoxyphenyl)‐4‐(4‐phthalimidobutyl)piperazine (NAN‐190). The LQFM032 did not alter mnemonic activity. Moreover, the anxiolytic‐like activity of LQFM032 was antagonized by mecamylamine. In summary, LQFM032 showed benzodiazepine and nicotinic pathways mediated anxiolytic‐like activity without altering the mnemonic activity.