Sedative, hypnotic and anticonvulsant activities of the ethanol fraction from Rhizoma Pinelliae Praeparatum

Ethnopharmacological relevance

Rhizoma Pinelliae Praeparatum is the product of raw Rhizoma Pinellia processed with alkaline solution and Licorice, which had been widely used for treatment of insomnia in traditional Chinese medicine. The present study aimed to investigate the sedative, hypnotic and anticonvulsant activities of ethanol fraction from Rhizoma Pinelliae Praeparatum (EFRP) and to determine whether these effects were related to GABAergic mechanism.

Materials and methods

The sedative, hypnotic and anticonvulsant activities of EFRP were investigated with locomotion activity, pentobarbital-induced sleeping and nikethamide (NKTM)-induced convulsion tests, respectively. Additionally, the effects of flumazenil (an antagonist of GABA_A receptor) and l-malic acid (blocker of synthetic enzyme for GABA) on the hypnotic activity of EFRP were evaluated.

Results

EFRP at dose of 12 g/kg significantly inhibited the locomotion activity of mice. EFRP showed synergic effect on pentobarbital-induced sleeping by increased numbers of mice falling asleep, reduced the sleep latency and prolonged the sleeping time. l-malic acid and flumazenil inhibited the augment effects of EFRP on pentobarbital-induced sleeping. EFRP promoted a significant protection to NKTM-induced convulsion, by prolonged the death latency and decreased mortality.

Conclusion

EFRP possessed sedative, hypnotic and anticonvulsant activities and these activities may be related to the GABAergic system.     

Anti-inflammatory and antinociceptive properties of the leaves of Eriobotrya japonica

Aim of the study

The leaves of Eriobotrya japonica Lindl. have been widely used as a traditional medicine for the treatment of many diseases including coughs and asthma. The present study was designed to validate the anti-inflammatory and antinociceptive properties of the n-BuOH fraction of E. japonica (LEJ) leaves.

Materials and methods

The anti-inflammatory properties of LEJ were studied using IFN-γ/LPS activated murine peritoneal macrophage model. The antinociceptive effects of LEJ were assessed using experimental models of pain, including thermal nociception methods, such as the tail immersion test and the hotplate test, and chemical nociception induced by intraperitoneal acetic acid and subplantar formalin in mice. To examine the possible connection of the opioid receptor to the antinociceptive activity of LEJ, we performed a combination test with naloxone, a nonselective opioid receptor antagonist.

Results

In the IFN-γ and LPS-activated murine peritoneal macrophage model, LEJ suppressed NO production and iNOS expression via down-regulation of NF-κB activation. It also attenuated the expression of COX-2 and the secretion of pro-inflammatory cytokines like TNF-α and IL-6. Moreover, LEJ also demonstrated strong and dose-dependent antinociceptive activity compared to tramadol and indomethacin in various experimental pain models. In a combination test using naloxone, diminished analgesic activities of LEJ were observed, indicating that the antinociceptive activity of LEJ is connected with the opioid receptor.

Conclusions

The results indicate that LEJ had potent inhibitory effects on the inflammatory mediators including nitric oxide, iNOS, COX-2, TNF-α and IL-6 via the attenuation of NF-κB translocation to the nucleus. LEJ also showed excellent antinociceptive activity in both central and peripheral mechanism as a weak opioid agonist. Based on these results, LEJ may possibly be used as an anti-inflammatory and an analgesic agent for the treatment of pains and inflammatory diseases.     

Antinociceptive effect of extracts and compounds from Hofmeisteria schaffneri

Ethnopharmacological relevance

Hofmeisteria schaffneri (Asteraceae) is a medicinal plant widely commercialized in the most important Markets of Mexico City for the treatment of gastro-intestinal complaints and skin afflictions.

Aim of the study

The main goals of this study were to establish the potential acute toxicity and the antinociceptive activity in animal models of several preparations and compounds from Hofmeisteria schaffneri.

Materials and methods

The aqueous and organic extracts as well as the essential oil of Hofmeisteria schaffneri were prepared by infusion, maceration and hydrodistillation, respectively. Investigation of the acute toxicity was accomplished by the Lorke method. The antinociceptive effect was assessed using the writhing and the hot plate tests. Natural compounds were isolated by standard phytochemical procedures. In addition, a few thymol esters were prepared by chemical synthesis. The stability of natural and synthetic esters was qualitatively analyzed by measuring their susceptibility to hydrolysis by pig liver estearase and mouse plasma at 37 °C.

Results

The LD₅₀ for each preparation tested was higher than 5000 mg/kg revealing that they were not toxic to mice after exposure for short space of time. On the other hand, the extracts showed significant antinociceptive effect when tested in the hot plate model. The most active natural product as antinociceptive agent was hofmeisterin III (1) which also was the most stable in the stability study. Its pharmacological effect seems to be partially mediated by an opioid mechanism since naloxone inhibits its action. Using compound 1 as a lead molecule, several synthetic thymol esters were prepared and only compounds 13, 15 and 17 were antinoceptive at the dose of 1 mg/kg.

Conclusions

The present investigation provided evidence of the efficacy of several preparations of Hofmeisteria schaffneri as antinociceptive agents. The most active preparation was the essential oil which contained large amount of hofmeisterin III (1) and other thymol derivatives. Some novel synthetic analogs of hofmeisterin III with antinociceptive properties were discovered. The nature of the ester chain of these analogs did not have a clear impact on the antinociceptive activity. The phyto-preparations analyzed in this study were not toxic to mice according to the Lorke's test; therefore considering their long term use of the plant they might be secure for human consumption.     

Characterisation of the anti-inflammatory and antinociceptive activities of the Hyptis pectinata (L.) Poit essential oil

Aim of the study

Hyptis pectinata Poit (Lamiaceae) is grown in the northeastern regions of Brazil and is popularly known as “sambacaitá” or “canudinho”. It is extensively used in folk medicine to treat inflammatory conditions, bacterial infections, pain, and cancer.

Materials and methods

Hyptis pectinata essential oil (EO, 10, 30, and 100 mg/kg, p.o.) and the reference drugs morphine (5 mg/kg, p.o.) and acetylsalicylic acid (ASA, 200 mg/kg, p.o.) were evaluated using models for analgesia (acetic acid-induced contortions and hot plate) or inflammation (formalin-induced licking response and the subcutaneous air-pouch model). To elucidate the EO's mechanism of action, animals were pre-treated with the opioid receptor antagonist naloxone (1 mg/kg, i.p.), the cholinergic antagonist atropine (1 mg/kg, i.p.), or l-nitro arginine methyl ester (l-NAME, 3 mg/kg, i.p.) 30 min prior to the oral administration of the EO.

Results

The EO significantly inhibited the number of writhings and the time the animals spent licking their formalin-injected paws (second phase). The EO, at doses of 30 and 100 mg/kg, increased baseline measurements and area under the curve measurements in the hot plate model, respectively. The administration of naloxone reversed the antinociceptive effect of the EO in the hot plate model. l-NAME significantly reversed the effects of the EO in the contortions and hot plate models. Atropine completely reversed the antinociceptive activity of the EO in all models. Additionally, the EO inhibited the inflammatory process induced by subcutaneous carrageenan injection by reducing cell migration, exudate volume, protein concentration, and inflammatory mediators (nitric oxide, prostaglandin E2, IL-6, and TNF-α) produced in the pouch.

Conclusions

Our results indicate that the Hyptis pectinata essential oil exhibits antinociceptive effects, likely mediated by opioid and cholinergic receptors, and anti-inflammatory activity through the inhibition of nitric oxide and PGE2 production.     

Antinociceptive activity of methanolic extract of Acmella uliginosa (Sw.) Cass

Ethnopharmacological relevance

Acmella uliginosa (Sw.) Cass. is a medicinal herbaceous plant that is commonly used by the Malay community in Malaysia to relieve pain often associated with mouth ulcers, toothache, sore throat, and stomach ache.

Aim

The study was carried out to investigate the antinociceptive effect of the methanolic extract of A. uliginosa (Sw.) Cass. flowers (MEAU) using murine models of chemicals and thermal nociception.

Materials and methods

Chemicals (acetic acid-induced abdominal constriction and formalin-, capsaicin-, glutamate-induced paw licking test) and thermal models (hot plate test) of nociception in mice were employed to evaluate the MEAU analgesic effect. The extract was given via oral administration at doses of 3, 10, 30 and 100 mg/kg.

Results

It was demonstrated that MEAU produced significant antinociceptive response in all the chemical- and thermal-induced nociception models, which indicates the presence of both centrally and peripherally mediated activities. Furthermore, the reversal of antinociception of MEAU by naloxone suggests the involvement of opioid system in its centrally mediated analgesic activity. Moreover, MEAU-treated mice did not show any significant motor performance alterations. No mortality and signs of toxicity were recorded following treatment of the MEAU.

Conclusion

The results from the present study appear to support the folkloric belief in the medicinal properties of A. uliginosa (Sw.) Cass. which against pain at both central and peripheral levels, in which the central antinociception is probably due to the participation of the opioid receptors.     

Anti-inflammatory and antinociceptive effects of the stem bark of Byrsonima intermedia A. Juss

Ethnopharmacological relevance

Byrsonima intermedia A. Juss. is popularly known as “murici pequeno” and is native to the Brazilian Cerrado. This species has been used as an antimicrobial, anti-hemorrhagic, anti-diarrheal and anti-inflammatory. Nevertheless, scientific information regarding Byrsonima intermedia is limited; there are no reports related to its possible anti inflammatory and antinociceptive effects. This study employed in vivo inflammatory and nociceptive models to evaluate the scientific basis for the traditional use of Byrsonima intermedia.

Materials and methods

Carrageenan-induced paw edema, peritonitis and fibrovascular tissue growth induced by s.c. cotton pellet implantation tests were used to investigate the anti-inflammatory activity of Byrsonima intermedia aqueous extract (BiAE) in rats. Mechanical nociceptive paw, formalin and hot plate tests were used to evaluate the antinociceptive activity in mice. High-performance liquid chromatography (HPLC), phytochemistry screening and determination of total phenolics and flavonoids were used to determine the chemical profile of the BiAE.

Results

BiAE at test doses of 30-300 mg/kg p.o. clearly demonstrated anti-inflammatory effects by reduced carrageenan-induced paw edema, by inhibited leukocyte recruitment into the peritoneal cavity and, in the model of chronic inflammation, by using the cotton pellet-induced fibrovascular tissue growth in rats. The extracts at test doses of 30-300 mg/kg p.o. clearly demonstrated antinociceptive activity in all tests. Administration of the opioid receptor antagonist naloxone completely inhibited the antinociceptive effect induced by BiAE (100 mg/kg).

Conclusion

BiAE markedly exhibits anti-inflammatory action in rats and antinociceptive activity in mice. Thus, it may be useful in the treatment of inflammatory hyperalgesic disorders, which supports previous claims of its traditional use.     

Sedative, vasorelaxant, and cytotoxic effects of convolvulin from Ipomoea tyrianthina

Aim of the study

Ipomoea tyrianthina has been used in Mexican traditional medicine as a mild purgative, for the treatment of nervous disorders, and against tumors. In this study, the effect of convolvulin (an ether-insoluble resin glycoside) from the root of Ipomoea tyrianthina on: Central Nervous System; as spasmolytic and vasodilator; cytotoxic against cancer cell lines is evaluated.

Materials and methods

Convolvulin isolated from the root of Ipomoea tyrianthina (IT-EM) was tested on pentylentetrazole induced seizures, pentobarbital-induced hypnosis, release of GABA and glutamic acid, isolated rat aorta and ileum rings, and against Caco-2 and KB cell lines.

Results

IT-EM increased the hypnotic effect induced by pentobarbital and the release of GABA in brain cortex of mice, but did not protect mice against pentylenetetrazole-induced convulsions. IT-EM produced a significant vasodilator effect in concentration- and endothelium-dependent manners on isolated rat aorta, but did not inhibit significantly contractions on rat ileum, colon, and jejune rings. IT-EM showed cytotoxic activity against nasopharyngeal carcinoma KB cell line.

Conclusions

Convolvulin (IT-EM) from Ipomoea tyrianthina has sedative effect, vasorelaxant effect in concentration- and endothelium-dependent manners, and cytotoxic activity against nasopharyngeal carcinoma KB cell line.     

Anti-inflammatory and antinociceptive effects of Arrabidaea brachypoda (DC.) Bureau roots

Aim of the study

Arrabidaea brachypoda (DC.) Bureau has been used to relieve general pain, painful joints and kidney stones in Brazilian folk medicine. Nevertheless, scientific information regarding this species is scarce; there are no reports related to its possible analgesic and anti-inflammatory effects. This study was aimed at evaluating the traditional use of Arrabidaea brachypoda root using in vivo inflammatory and nociceptive models.

Materials and methods

Carrageenan-induced paw edema, peritonitis and fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the anti-inflammatory activity of Arrabidaea brachypoda roots ethanolic extract (AbEE) in rats. Formalin and acetic acid-induced writhing tests were used to investigate the antinociceptive activity in mice. High-performance liquid chromatography (HPLC) was used to determine the fingerprint chromatogram of AbEE.

Results

The AbEE at test doses of 30-300 mg/kg p.o. demonstrated anti-inflammatory effects. AbEE reduced paw edema induced by carrageenan, inhibited leukocyte recruitment into the peritoneal cavity and, in the model of chronic inflammation using the cotton pellet-induced fibrovascular tissue growth in rats, significantly inhibited the formation of granulomatous tissue. The extracts at test doses of 30-300 mg/kg p.o. clearly demonstrated antinociceptive activity, except during the first phase of the formalin test. The presence of quercetin and phenolic compounds in the extract Arrabidaea brachypoda was confirmed using HPLC.

Conclusion

Arrabidaea brachypoda ethanol extract markedly demonstrated anti-inflammatory action in rats and antinociceptive activity in mice, which supports the previous claims of traditional use.     

Growth inhibitory and apoptosis inducing by effects of total flavonoids from Lysimachia clethroides Duby in human chronic myeloid leukemia K562 cells

Ethnopharmacological relevance

Lysimachia clethroides Duby is a traditional Chinese medicinal herb has been used in China to treat edema, jaundice diseases, hepatitis, tumor and inflammations, but the anti-tumor mechanisms are unclear.

Aim of the study

The present study was undertaken to investigate if total flavonoids from Lysimachia clethroides Duby (ZE4) possesses anti-cancer effects through apoptotic pathways in human chronic myeloid leukemia K562 cells.

Materials and methods

K562 cells were treated with different concentrations of ZE4 at different time intervals. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was assessed by flow cytometry, Hoechst 33258 staining and COMET assay. Western blot analysis was used to detect Bcl-2, Trail and DR5 expressions.

Results

15 flavonoids were isolated and identified from ZE4. ZE4 could inhibit the growth of K562 cells significantly by induction of apoptosis. Marked morphological changes of apoptosis, DNA fragmentation and single DNA strand breakages were observed clearly after treatment of ZE4. Bcl-2 expression was down-regulated remarkably while Fas, Trail and DR5 up-regulated when apoptosis occurred.

Conclusions

This result suggests that total flavonoids of Lysimachia clethroides Duby exert potential anti-cancer activity through growth inhibition and apoptosis in K562 cells.     

Identification of a new antinociceptive alkaloid isopropyl N-methylanthranilate from the essential oil of Choisya ternata Kunth

Ethnopharmacological relevance

Mexican people employed infusion of leaves of Choisya ternata Kunth for their antispasmodic and “simulative properties”.

Aim of the study

In the present study the detailed GC and GC-MS analyses of the essential oil of Choisya ternata Kunth (Rutaceae) were performed. The presence of a minor constituent isopropyl N-methylanthranilate (1) was revealed among other identified volatiles. A synthesis of 1 was undertaken in order to corroborate this find and obtain gram quantities that would allow the testing of its biological activity (peripheral and central antinociceptive activity).

Materials and methods

The oils were investigated by GC and GC-MS. Synthesized compounds were spectrally characterized (UV-Vis, IR, 1D and 2D NMR, MS). The obtained synthetic samples of compounds were assayed for peripheral and central antinociceptive activity in two models (effects on acetic acid induced writhing in mice and the hot plate test for nociception).

Results

Detailed GC and GC-MS analyses of the essential oil of Choisya ternata Kunth (Rutaceae) among 157 other identified volatiles revealed the presence of a minor constituent isopropyl N-methylanthranilate (1). Compound 1, named ternanthranin, is therefore detected as a natural product for the first time with a very restricted occurrence (samples of several citrus oils were screened for the presence of 1). The antinociceptive activities were assayed for ternanthranin, the two other synthetic analogs, methyl and propyl N-methylanthranilate, as well as the essential oil and the crude ethanol extract of the leaves. The results clearly demonstrate a very high (even significant at 0.3 mg/kg) dose dependent activity for the anthranilates (and the extracts). Isopropyl N-methylanthranilate showed the highest, while methyl N-methylanthranilate showed the lowest activity (with the methyl ester at 3 mg/kg still better than acetylsalicylic acid, at 200 mg/kg, in the first, or comparable with morphine, at 5 mg/kg, in the second test).

Conclusion

This study once again revealed that detailed investigations of plant species with ethnopharmacologically documented activity may yield new natural compounds—a new alkaloid (ternanthranin), a volatile simple anthranilate that can be considered responsible for the antinociceptive activity of the crude plant extracts.     

Antinociceptive and antiinflammatory activities of Adiantum latifolium Lam.: Evidence for a role of IL-1β inhibition

Aim of study

Adiantum, one of the most widely distributed genera of the family Pteridaceae, is employed in folk medicine worldwide. Adiantum latifolium Lam. has been used in Latin American traditional medicine as anxiolytic, analgesic and antiinflammatory. The present study investigates the antinociceptive and antiinflammatory properties of the methanolic extract of Adiantum latifolium (MEA) in animal models of pain and inflammation to confirm its medicinal use.

Material and methods

The antinociceptive and antiinflammatory activities of MEA were evaluated using the writhing, formalin, and tail-flick tests, carrageenan-induced paw edema and arachidonic acid-induced ear edema. Mice motor performance was evaluated in the rota rod test and the acute toxicity evaluated over 14 days.

Results

Intraperitoneal (1-100 mg/kg) or oral (100-400 mg/kg) administration of MEA produced a dose-related inhibition of acetic acid-induced writhing in mouse. Furthermore, treatment with MEA (100 mg/kg) inhibited both the early and late phases of formalin-induced hypernociception. In contrast, MEA (100 mg/kg/IP) did not prevent the thermal nociception in the tail-flick test. In addition, MEA (100 and 200 mg/kg/IP) inhibited important events related to the inflammatory response induced by carrageenan or arachidonic acid, namely local edema and increase in tissue interleukin-1β levels. MEA (300 mg/kg/IP)-treated mice did not show any motor performance alterations. Over the study period of 14 days, there were no deaths or toxic signs recorded in the group of mice given 1000 mg/kg of MEA.

Conclusion

The results demonstrate that Adiantum latifolium has antinociceptive and antiinflammatory activities, acting through the inhibition of IL-1β production.     

Neuropharmacological study of Dracocephalum moldavica L. (Lamiaceae) in mice: sedative effect and chemical analysis of an aqueous extract

Ethnopharmacological relevance

Dracocephalum moldavica is used as a tranquilizer and as remedy for nervous conditions relief in the Mexican traditional medicine. Despite its intensive use no literature reported neuropharmacological studies on Dracocephalum moldavica as yet.

Aim of the study

The sedative, anxiolytic-like and antidepressant-like effects of the aqueous extract of aerial parts of Dracocephalum moldavica (Lamiaceae) (DM) were evaluated in behavioral models in mice. The general toxic effects of DM were evaluated as well as their chemical analysis was performed.

Materials and methods

DM effects were evaluated on pentobarbital-induced sleeping time (SPT), the hole-board (HBT), and the avoidance exploratory behavior (AEBT) tests and on the forced swimming test (FST). General activity and motor coordination were evaluated in the open field (OFT) and Rota-rod tests, respectively. The acute toxicity of DM was determinate by its LD₅₀ dose. The chemical analyses DM were performed by chromatographic and HPLC–ESI-MS techniques.

Results

DM prolonged the pentobarbital-induced sleeping time, induced sedation in the HBT, decreased spontaneous activity and produced motor coordination impairment in mice. However, DM did not show anxiolytic effects in the AEBT or HBT and it was not effective in FST. The DM-treatment produced mortalities with LD₅₀ = 470 mg/kg body weight.The HPLC–ESI-MS analysis of DM revealed that (acacetin, apigenin and luteolin)-7-O-β-d-(6″-O-malonyl)-glucoside derivates are the main compounds of DM.

Conclusions

DM induced sedative actions and a general inhibition of CNS activity observed by the decrease of animals’ general activity, motor coordination and exploration.     

Antinociceptive activity of methanol extract of fruits of Capparis ovata in mice

Ethnopharmacological relevance

Capparis ovata Desf. and Capparis spinosa L. have wide natural distribution in Turkey and they are consumed in pickled form. Flower buds, root bark, and fruits of the plant are used in folk medicine due to their analgesic, wound healing, cell regeneration, tonic, and diuretic effects.

Aim of the study

In this study, we attempted to identify the possible antinociceptive action of methanol extract prepared from fruits of Capparis ovata.

Materials and methods

Using tail immersion, hot plate and writhing tests, the antinociceptive effect of the methanol extract of Capparis ovata (MEC) fruits was assessed after intraperitoneal administration into mice. Morphine sulfate (5 mg/kg; i.p.) and diclofenac (10 mg/kg; i.p.) were used as reference analgesic agents. Naloxone (5 mg/kg; i.p.) was also tested.

Results

MEC was studied at the doses of 50, 100, and 200 mg/kg (i.p.) and exhibited significant antinociceptive activities in all tests used. The above-mentioned doses of the extract reduced the writhing responses by 32.21, 55.70, and 68.36%, respectively. MPE% were increased by 7.27, 12.07, 14.60% in the tail immersion, and 7.88, 11.71, 16.73% in the hot plate test at the tested doses, respectively. Naloxone antagonized antinociceptive effect at the doses of 100 and 200 mg/kg whereas partially antagonized the effect of MEC at the dose of 50 mg/kg.

Conclusions

Based on the results obtained, it can be concluded that MEC has antinociceptive effects both at the peripheral and central levels.     

Antinociceptive and anti-inflammatory potential of extract and isolated compounds from the leaves of Salvia officinalis in mice

Ethnopharmacological relevance

Salvia officinalis L. has been used as a traditional herbal medicine for gastric disturbances and inflammatory processes. This study investigated the toxicological, antinociceptive and anti-inflammatory effects of the hydroalcoholic extract (HE) from leaves of Salvia officinalis and its isolated compounds in mice.

Materials and methods

Mice were treated with HE before the induction of nociceptive response by chemical agents (acetic-acid, formalin, glutamate, capsaicin and cinnamaldehyde). Total leukocytes and plasma extravasation induced by acetic acid and paw oedema induced by glutamate, capsaicin and cinnamaldehyde were also measured. The antinociceptive effect of carnosol and ursolic acid/oleanolic acid were evaluated on formalin and cinnamaldehyde models.

Results

In the acute toxicity test the value of estimated LD50 for HE was 44.7579 g/kg. Oral administration of HE (10, 30 and 100 mg/kg) inhibited the number of writhings, total leukocytes and plasma extravasation induced by acetic acid. In the formalin test, HE reduced both neurogenic and inflammatory phases, effect that was affected by naloxone. The glutamate-, capsaicin- and cinnamaldehyde-induced nociception and paw oedema were reduced by HE at doses that did not affect the locomotor activity of mice in the open field test. Carnosol (10 mg/kg) and ursolic acid/oleanolic acid (30 mg/kg) inhibited the inflammatory phase of formalin and the nociception and mechanical allodynia induced by cinnamaldehyde.

Conclusions

These results demonstrate that HE presents significant anti-inflammatory and also antinociceptive effects on chemical behavioral models of nociception that involves an opioid mechanism. In addition, carnosol and ursolic acid/oleanolic acid contained in this plant appears to contribute for the antinociceptive property of the extract, possibly through a modulatory influence on TRPA1-receptors. However, further studies regarding the precise site and the mechanism of action of HE and carnosol and ursolic acid/oleanolic acid merited exploring further.     

Xanthine oxidase inhibitory properties of Czech medicinal plants

Aim of the study

To investigate in vitro xanthine oxidase inhibitory properties of plants traditionally used in Czech Republic and Central-East Europe region for gout, arthritis or rheumatism treatment.

Materials and methods

Methylene chloride-methanolic and two ethanolic extracts of 27 plant species were screened for in vitro xanthine oxidase inhibitory activity using a spectrophotometric method.

Results

Around 50% of the species exhibited some degree of xanthine oxidase inhibitory properties at 200 μg/mL, showing a moderate correlation (r = 0.59) with total phenol content. The most active were methylene chloride-methanolic extracts of Populus nigra and Betula pendula, with IC₅₀ of 8.3 and 25.9 μg/mL, respectively, followed by 80% ethanolic extract of Caryophyllus aromaticus and Hypericum perforatum, both under 50 μg/mL.

Conclusions

Populus nigra and Betula pendula were identified as species with the highest xanthine oxidase inhibitory potential in our study. This correlates with the ethnobotanical data on their use in Central European folklore and provides the basis for further investigation on these plants.     

Rosewood oil induces sedation and inhibits compound action potential in rodents

Aim of the study

Aniba rosaeodora is an aromatic plant which has been used in Brazil folk medicine due to its sedative effect. Therefore, the purpose of the present study was to evaluate the sedative effect of linalool-rich rosewood oil in mice. In addition we sought to investigate the linalool-rich oil effects on the isolated nerve using the single sucrose-gap technique.

Materials and methods

Sedative effect was determined by measuring the potentiation of the pentobarbital-induced sleeping time. The compound action potential amplitude was evaluated as a way to detect changes in excitability of the isolated nerve.

Results

The results showed that administration of rosewood oil at the doses of 200 and 300 mg/kg significantly decreased latency and increased the duration of sleeping time. On the other hand, the dose of 100 mg/kg potentiated significantly the pentobarbital action decreasing pentobarbital latency time and increasing pentobarbital sleeping time. In addition, the effect of linalool-rich rosewood oil on the isolated nerve of the rat was also investigated through the single sucrose-gap technique. The amplitude of the action potential decreased almost 100% when it was incubated for 30 min at 100 μg/ml.

Conclusions

From this study, it is suggested a sedative effect of linalool-rich rosewood oil that could, at least in part, be explained by the reduction in action potential amplitude that provokes a decrease in neuronal excitability.     

Anti-inflammatory and antinociceptive effects of Garcinia brasiliensis

Aim of the study

In Brazilian folk medicine, the leaves of Garcinia brasiliensis are used to treat tumors, inflammation of the urinary tract and arthritis as well as to relieve pain. Nevertheless, scientific information regarding Garcinia brasiliensis is limited; there are no reports related to its possible anti-inflammatory and antinociceptive effects. This study employed in vivo inflammatory and nociceptive models to evaluate the scientific basis for the traditional use of Garcinia brasiliensis.

Materials and methods

Carrageenan-induced paw edema, peritonitis and fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the anti-inflammatory activity of Garcinia brasiliensis ethanolic extract (GbEE) in rats. Formalin and acetic acid-induced writhing tests were used to investigate the antinociceptive activity in mice.

Results

GbEE at test doses of 30-300 mg/kg p.o. clearly demonstrated anti-inflammatory effects by reduced paw edema induced by carrageenan, inhibited leukocyte recruitment into the peritoneal cavity, and in the model of chronic inflammation using the cotton pellet-induced fibrovascular tissue growth in rats, the GbEE significantly inhibited the formation of granulomatous tissue.The extracts at test doses of 30-300 mg/kg, p.o., clearly demonstrated antinociceptive activity, except for the first phase of the formalin test.

Conclusion

GbEE markedly demonstrated anti-inflammatory action in rats and antinociceptive activity in mice, which supports previous claims of the traditional use of species of the Garcinia genus for inflammation and pain.     

Hypotensive effect of aqueous extract of Averrhoa carambola L. (Oxalidaceae) in rats: an in vivo and in vitro approach

Aim of the study

Averrhoa carambola L. (Oxalidaceae) leaves are used in Brazilian traditional medicine to treat hypertension. This study was conducted to evaluate the hypotensive effect of the aqueous extract of Averrhoa carambola (AEAc) and its underlying mechanisms in the isolated rat aorta.

Materials and methods

The effect of AEAc on the mean arterial pressure (MAP) was determined in vivo in anesthetized rats. In vitro, thoracic aortic rings were isolated and suspended in organ baths, and the effects of AEAc were studied by means of isometric tension recording experiments. In HPLC analysis, the fingerprint chromatogram of AEAc was established.

Results

In normotensive rats, AEAc (12.5-50.0 mg/kg, i.v.) induced dose-dependent hypotension. In vitro, AEAc caused a depression in the E_max response to phenylephrine without a change in sensibility. Also, in a depolarized Ca²⁺-free medium, AEAc inhibited CaCl₂-induced contractions and caused a concentration-dependent rightward shift of the response curves, indicating that AEAc inhibited the contractile mechanisms involving extracellular Ca²⁺ influx.

Conclusions

These results demonstrate the hypotensive effects of AEAc, and these effects may, in part, be due to the inhibition of Ca²⁺, which supports previous claims of its traditional use.     

Hypnotic effects and binding studies for GABAA and 5-HT2C receptors of traditional medicinal plants used in Asia for insomnia

Aim of the study

Many medicinal plants have been used for treatment of insomnia in Asia. However, scientific evidence and precise mechanism for their sedative-hypnotic activity have not been fully investigated. Thus, we investigated the binding activity of the oriental plant extracts (mainly from Korea and Japan) to the well-known molecular targets for sleep regulation, GABA_A and 5-HT_2C receptors. Following the binding assay, sedative-hypnotic effects of the extracts with high affinity were examined in an animal model of sleep.

Materials and methods

Aqueous and ethanol extracts of 15 medicinal plants were tested for binding at the benzodiazepine site of GABA_A receptor and 5-HT site of 5-HT_2C receptor. The sedative-hypnotic effects of selected extracts were evaluated by measuring the sleep latency and sleep duration during pentobarbital-induced sleep in mice after oral administration of extracts.

Results

In the GABA_A assay, the ethanol extracts of licorice and danshen displayed concentration-dependent, high affinity binding, whereas in the 5-HT_2C assay, the ethanol extracts of ginseng and silk tree showed high affinity. Among these extracts we tested previously uncharacterized licorice and silk tree for hypnotic effects. We found the ethanol extracts of licorice and silk tree significantly decreased sleep latency and increased sleep duration in pentobarbital-induced sleep.

Conclusions

We demonstrate for the first time that licorice and silk tree have the sedative-hypnotic activity possibly by modulating GABA_A and 5-HT_2C receptors. We propose that licorice and silk tree might be effective candidates for treatment of insomnia.