María Eva González-Trujano

Sedative and anxiolytic efficacy of Tilia americana var. mexicana inflorescences used traditionally by communities of State of Michoacan, Mexico

AIM OF THE STUDY Increasing demand of herbal products acquired in stores and markets, as well as medicinal plants collected for personal consume are a known modern tendency. In this study, the ethnomedicinal use of Tilia americana var. mexicana inflorescences as sedative and anxiolytic is reinforced by examinating inflorescences used by communities of the State of Michoacan, Mexico. MATERIALS AND METHODS Experimental mouse models were used to evaluate the sodium pentobarbital (SP)-induced hypnosis potentiation, ambulatory activity, as well as sedative and anti-anxiety responses via oral administration of the aqueous extracts (10, 30 and/or 100 and 300mg/kg). RESULTS All samples tested produced a lengthening in the time of SP. Moreover, a significant attenuation in the anxiety-response in the plus-maze test and a diminution in both the head dipping response and ambulatory activity were observed resembling the response to diazepam (0.3mg/kg, i.p.). TLC profiles of the samples showed similar pattern of flavonoids; HPLC-DAD exhibited peaks identified as derived of quercetin and kaempferol that may be responsible for the plant activity. CONCLUSIONS Our results demonstrate that inflorescences of stored specimens obtained from popular local markets show the same effectiveness with regard to sedative and anxiolytic-like actions than freshly collected samples. Since no toxicity was observed through this route of administration (up to 5000mg/kg); therefore, it suggests that this plant is secure when used as tranquilizer in folk medicine.

Antinociceptive effect and GC/MS analysis of Rosmarinus officinalis L. essential oil from its aerial parts

The rationale of this investigation was to examine the antinociceptive properties of the essential oil obtained from Rosmarinus officinalis aerial parts, using a rat model of arthritic pain. The essential oil (100, 300 and 600 mg/kg, I. P.) produced a dose-dependent antinociceptive effect, manifested as a significant reduction in the dysfunction in the pain-induced functional impairment model in the rat (PIFIR model), mainly at high doses. Chemical constituents of the essential oil were further analyzed by gas chromatography-mass spectrometry (GC/MS). The major compounds in the essential oil were alpha-pinene (14.10 %), camphene (11.47 %), beta-pinene (12.02 %), myrcene (3.31 %), alpha-phellandrene (7.87 %), eucalyptol (8.58 %), 2-bornanone (3.42 %), camphor (8.75 %), isoborneol (3.48 %), borneol (4.85 %) and borneol acetate (6.49 %). The antinociceptive effects of R. officinalis essential oil were tested in combination with 0.12 mg/kg WAY100635, s. c. (an antagonist of 5-HT(1A) receptors) or 1 mg/kg naloxone, i. p. (an antagonist of endogenous opioids receptors), demonstrating in both cases an inhibition of the antinociceptive response. This study suggests an involvement, at least in part, of the serotonergic system via 5-HT(1A) receptors and endogenous opioids in the antinociceptive effect of R. officinalis essential oil in the PIFIR model.

Some pharmacological effects of the ethanol extract of leaves of Annona diversifolia on the central nervous system in mice

In the present study we investigated some neuropharmacological effects of the ethanol extract of the leaves of Annona diversifolia (Annonaceae). Intraperitoneal administration of the extract delayed the onset of clonic seizures induced by pentylenetetrazole and delayed the time in the ‘rota‐rod’ and ‘swimming’ test. In addition, the extract augmented the duration of sleeping time induced by sodium pentobarbital. These results indicate that the ethanol extract of the leaves of A. diversifolia has depressant activity on the central nervous system. Copyright

Spasmolytic activity of Rosmarinus officinalis L. involves calcium channels in the guinea pig ileum.

ETHNOPHARMACOLOGICAL RELEVANCE Rosmarinus officinalis L. is a plant used around the world for its properties to cure pain in several conditions, such as arthritic and abdominal pain or as an antispasmodic; however, there are no scientific studies demonstrating its spasmolytic activity. Therefore, the aim of the present study was to investigate the effect of an ethanol extract from Rosmarinus officinalis aerial parts and the possible mechanism involved by using rings from the isolated guinea pig ileum (IGPI). MATERIALS AND METHODS The IGPI rings were pre-contracted with potassium chloride (KCl; 60 mM), acetylcholine (ACh; 1 × 10(-9) to 1 × 10(-5)M) or electrical field stimulation (EFS; 0.3 Hz of frequency, 3.0 ms of duration and 14 V intensity) and tested in the presence of the Rosmarinus officinalis ethanol extract (150, 300, 600 and 1 200 μg/mL) or a referenced smooth muscle relaxant (papaverine, 30 μM). In addition, the possible mechanism of action was analyzed in the presence of hexametonium (a ganglionic blocker), indomethacine (an inhibitor of prostaglandins), l-NAME (a selective inhibitor of the nitric oxide synthase) and nifedipine (a calcium channel blocker). RESULTS Rosmarinus officinalis ethanol extract exhibited a significant and concentration-dependent spasmolytic activity on the contractions induced by KCl (CI(50) = 661.06 ± 155.91 μg/mL); ACh (CI(50) = 464.05 ± 16.85 μg/mL) and EFS (CI(50) = 513.72 ± 34.13 μg/mL). Spasmolytic response of Rosmarinus officinalis (600 μg/mL) was reverted in the presence of nifedipine 1 μM, but not in the presence of hexamethonium 0.5mM, indomethacine 1 μM or L-NAME 100 μM. CONCLUSION The present results reinforce the use of Rosmarinus officinalis as antispasmodic in folk medicine. Moreover, it is demonstrated the involvement of calcium channels in this activity, but not the participation of nicotinic receptors, prostaglandins or nitric oxide.

Antinociceptive effectiveness of triterpenes from rosemary in visceral nociception

ETHNOPHARMACOLOGICAL RELEVANCE Rosemary is a species used worldwide as a common spice, but also in folk medicine for their therapeutic properties against abdominal pain. The rationale of this study was to examine the involvement of triterpenes and to compare their effectiveness in the antinociceptive effect of an ethanol extract of Rosmarinus officinalis L. (Lamiaceae). MATERIAL AND METHODS Fractionation and HPLC analyses allowed the identification of a mixture of micromeric (121 mg/g), oleanolic (64 mg/g) and ursolic (83 mg/g) acids as partial antinociceptive responsible in an ethyl acetate fraction of R. officinalis by using the acetic acid-induced abdominal constrictions model in mice. RESULTS These triterpenes individually evaluated produced a significant and dose-dependent antinociceptive response with similar potency as follows: ED₅₀=1.1 mg/kg (0.9-1.3 mg/kg), 2.1 mg/kg (1.6-2.6 mg/kg) and 1.6 mg/kg (1.1-2.1 mg/kg), respectively, by using the intraperitoneal (i.p.) route of administration in mice. Their maximal antinociceptive efficacy resembled that produced by ketorolac (10 mg/kg, i.p.), a common clinic analgesic. CONCLUSION Our results provide evidence that these triterpenes participate in the antinociceptive activity of R. officinalis. In addition, each individual triterpene showed a similar potency to that observed with ketorolac, a non-steroidal anti-inflammatory drug, in this experimental model.

Antinociceptive and anti-inflammatory activities of a pomegranate (Punica granatum L.) extract rich in ellagitannins

Abstract Pomegranate (Punica granatum L.) has been used for centuries for the treatment of inflammatory diseases. However, there is a lack of comprehensive information focused on the properties of a certain pomegranate (poly)phenolic profile to cure pain and gastric injury induced by anti-inflammatory drugs. This study investigated the systemic effects of different doses of a HPLC-characterized pomegranate extract on the formalin-induced nociceptive behavior in mice. The effect of the extract against gastric injury caused by non-steroidal anti-inflammatory drugs and ethanol was also assessed. Pomegranate reduced nociception in both phases of the formalin test, suggesting central and peripheral activities to inhibit nociception. Indomethacin-induced gastric injury was not produced in the presence of pomegranate, which also protected against ethanol-induced gastric lesions. The present results reinforce the benefits of pomegranate (poly)phenolics in the treatment of pain as well as their anti-inflammatory properties.

Depressant effects of Agastache mexicana methanol extract and one of major metabolites tilianin.

OBJECTIVE To determine the depressant-like effects and the possible mechanism of action of tilianin isolated from active methanol extract of Agastache mexicana (A. mexicana). Also, to establish the pharmacophoric requirements of tilianin, as a possible ligand of GABAA/BZD receptor, by the alignment of diazepam, CGS-9896 and diindole, using a previously described pharmacophoric model. METHODS Tilianin (30 to 300 mg/kg, ip. and 300 mg/kg, po.) and methanol crude extract (10 to 300 mg/kg, ip. and 300 mg/kg po.) from A. mexicana were evaluated for potential sedative and anxiolytic-like response drugs by using open-field, hole-board, cylinder of exploration, plus-maze and sodium pentobarbital-induced hypnosis mice methods. RESULTS Methanol extract and tilianin showed anxiolytic-like activity from a dosage of 30 mg/kg, ip. or 300 mg/kg, po. and were less potent than diazepam 0.1 mg/kg, a reference anxiolytic drug used. Moreover, depressant activity of both potentiates sodium pentobarbital (SP)-induced sleeping time. The anxiolytic-like effect of 30 mg/kg ip. observed for the extract and tilianin, by using the plus-maze model, was partially prevented in the presence of flumazenil (a GABAA/BZD antagonist, 5 mg/kg ip.) but not in the presence of WAY 100635 (a selective 5-HT1A receptor antagonist, 0.32 mg/kg, ip.). Pharmacophoric modeling alignments of three agonist of GABAA/BZD allow identify seven chemical features. Tilianin contains six of the seven features previously determined. CONCLUSIONS Results indicate that tilianin is one of the bioactive metabolites in the anxiolytic-like activity of A. mexicana, reinforcing its central nervous system uses, where GABAA/BZD, but not 5-HT1A, receptors are partially involved.

Tagetes lucida Cav.: Ethnobotany, phytochemistry and pharmacology of its tranquilizing properties

ETHNOPHARMACOLOGICAL RELEVANCE Morelos State is one of the most important regions of Mexico where several plant species are used in traditional medicine to influence central nervous system (CNS) activity; for example Tagetes lucida Cav. AIM OF THE STUDY To investigate the ethnobotany, phytochemistry and pharmacology of the tranquilizing properties of T. lucida aerial parts. MATERIAL AND METHODS Data on the medicinal uses of T. lucida were explored by interviewing healers and merchants of local markets in different regions of Morelos State by using a questionnaire. Anxiolytic and/or sedative-like responses of the T. lucida were investigated in experimental models in mice such as: open-field, exploration cylinder, hole-board, plus-maze, and the barbituric-induced hypnosis potentiation. The possible mechanism of action was explored in the presence of WAY100635 (0.32mg/kg, i.p.) and flumazenil (10mg/kg, i.p.) antagonists. A feasible active compound was isolated and identified by using conventional chromatography, including UHPLC and MS (DART) [M+H]+ techniques. RESULTS Interviews of healers and merchants from ten local regions of Morelos State showed that they recommended T. lucida as infusion and as tincture for several culture-bound syndromes associated with the CNS. Anxiolytic and sedative-like activities of polar extracts were corroborated in the experimental models; these effects were inhibited in the presence of 5-HT1A and GABA/BDZ receptor antagonists. Dimethylfraxetin was identified as one possible active compound. CONCLUSIONS The results support the anxiolytic and sedative-like properties of T. lucida in traditional medicine by involving serotonergic and GABAergic neurotransmission and coumarinic constituents.

Alterations on the morphology, nitric oxide synthesis and activity of platelets reproduced in rats as possible biomarkers for depression are reversed by fluoxetine.

Biochemical markers associated with the prognosis of depression in humans are being described in the literature, whereas experimental studies in animal models in search for antidepressant strategies are lacking. The aim of this study was to evaluate platelet morphology, platelet activity and nitric oxide (NO) synthesis as possible biomarkers of depressive-like behavior by using FST alone and in the presence of fluoxetine. Naïve rats were compared to those receiving vehicle or fluoxetine at 10mg/kg i.p. in acute, subchronic and chronic administration in the FST. After behavioral assessment, platelets were isolated from blood samples and analyzed by flow cytometry to determine the platelet mitochondrial membrane potential and NO synthesis. In addition, HPLC and electron microscopy were used to examine 5-HT and tryptophan levels and morphology of platelets, respectively. Rats receiving vehicle and exposed to FST showed depressive-like behavior at all the times tested; after chronic FST rats showed a similar pattern of alteration in platelet morphology and in the studied as possible biochemical markers as those previously recognized in depressive humans. Depressive-like behavior in rats exposed to FST was prevented in the presence of fluoxetine administration at all the times tested and associated with the prevention of alterations in platelet morphology, platelet activity and NO synthesis, and/or in 5-HT concentrations. The results of the present study suggest that platelet function and morphology might be relevant markers for the prognosis of depression and the search for functional treatments. Besides, the relevance of FST as model to study this psychiatric illness is reinforced.

Nerol alleviates pathologic markers in the oxazolone-induced colitis model.

Nerol is a natural monoterpene with antinociceptive and anti-inflammatory properties. Its possible beneficial effects in ulcerative colitis and its corresponding mechanism of action have not been determined to date. The aim of this study was to investigate whether nerol prevents the appearance of pathological markers and hyperalgesia in oxazolone-induced colitis, and protects against gastric damage produced by ethanol. The experimental design included groups of oxazolone-treated mice receiving nerol at 10-300 mg/kg, p.o., or a reference drug (sulfasalazine, 100 mg/kg, p.o.) compared to sham and untreated groups. Gastric damage was evaluated in the absolute ethanol-induced ulcer model in rats. Variables measured in animals with oxazolone-induced colitis included weight loss, stool consistency and macroscopic colon damage; mechanical nociception was determined by the use of von Frey filaments, whereas levels of inflammatory cytokines were assessed by enzyme-linked immunosorbent assay. Nerol (30-300 mg/kg, p.o.) prevented or significantly decreased the pathological alterations observed in the oxazolone- induced colitis model. It also showed antinociceptive effects and reduced the increased levels of inflammatory cytokines (IL-13 and TNF-α). Gastric damage was also prevented starting at 10 mg/kg, p.o. In conclusion, our results provide evidence for a beneficial effect of nerol after colitis induction involving tissue protection, antinociception and modulation of the immunological system, suggesting the therapeutic potential of this monoterpene as a novel alternative in controlling ulcerative colitis.