Antipyretic and antinociceptive effects of Nauclea latifolia root decoction and possible mechanisms of action

Polyphenols and extracts from Zingiber roseum (Roxb.) Roscoe leaf mitigate pain, inflammation and pyrexia by inhibiting cyclooxygenase-2: an in vivo and in silico studies

Zingiber roseum (Roxb.) Roscoe, a perennial herb from the Zingiberaceae family, has a long history of traditional use in the treatment of several ailments including pain, inflammation, fever, cough, arthritis, skin diseases, and liver infections. This study sought to confirm the efficacy of Zingiber roseum (Roxb.) Roscoe leaves methanol extract (ZrlME) as reported in traditional usage by evaluating its analgesic, anti-inflammatory, and antipyretic capabilities. In addition, in silico molecular docking of the metabolites identified in ZrlME was studied to verify the experimental outcomes. ZrlME demonstrated strong dose-dependent analgesic efficacy against all analgesic tests. ZrlME (400 mg/kg) showed higher anti-inflammatory activity than the standard in the carrageenan-induced paw edema test model. A significant reduction of rectal temperature (3.97°F↓) was also recorded at the same dose of ZrLME after 24 h of treatment. Seven polyphenolic metabolites were identified and quantified by HPLC-DAD analysis, including 3, 4- dihydroxy benzoic acid, (-) epicatechin, rutin hydrate, p-coumaric acid, trans-ferulic acid, rosmarinic acid, and myricetin. Strong binding affinities (ranges from -5.8 to -8.5 Kcal/mol) between the aforesaid polyphenols and cyclooxygenase-2 were discovered. Moreover, molecular dynamics simulations (MDS) demonstrated that these polyphenols exhibit significant COX-2 inhibitory activity due to their high stability in the COX-2 active site. In computational prediction, the polyphenols were also found to be nontoxic, and a variety of biological activities, such as antioxidant, analgesic, anti-inflammatory, antipyretic, and hepatoprotective, were observed. The results of this study revealed that ZrlME possesses notable analgesic, anti-inflammatory, and antipyretic properties.

N-type calcium channel blockers: a new approach towards the treatment of chronic neuropathic pain

Neuropathic pain (NP) remains maltreated for a wide number of patients by the currently available treatments and little research has been done in finding new drugs for treating NP. Ziconotide (PrialtTM) had been developed as the new drug, which belongs to the class of ω-conotoxin MVIIA. It inhibits N-type calcium channels. Ziconotide is under the last phase of the clinical trial, a new non-narcotic drug for the management of NP. Synthetically it has shown the similarities with ω-conotoxin MVIIA, a constituent of poison found in fish hunting snails (Conus magus). Ziconotide acts by selectively blocking neural N-type voltage-sensitized Ca2+ channels (NVSCCs). Certain herbal drugs also have been studied but no clinical result is there and the study is only limited to preclinical data. This review emphasizes the N-type calcium channel inhibitors, and their mechanisms for blocking calcium channels with their remedial prospects for treating chronic NP.

Antipyretic Potential of 80% Methanol Extract and Solvent Fractions of Bersama abyssinica Fresen. (Melianthaceae) Leaves Against Yeast-Induced Pyrexia in Mice

Introduction

Since fever is a complicated physiological reaction to an infection or aseptic stimulus, finding safer solutions that are more potent and derived from plants is essential to resolving this issue. Bersama abyssinica (Melianthaceae) is traditionally used to treat fever, though this has yet to be proven scientifically.

Objective

The present study aimed to assess the antipyretic potential of leaf extract and solvent fractions of B. abyssinica.

Methods

The antipyretic activities of crude extract and solvent fractions of B. abyssinica leaves were evaluated using a yeast-induced pyrexia model at three different dose ranges (100mg/kg, 200mg/kg, and 400mg/kg) methanol extract as well as chloroform, ethyl acetate, and aqueous fractions to mice showing an increase in temperature of ≥0.5 °C. The rectal temperature of each mouse was recorded using a digital thermometer. To analyze the data, SPSS version 20 and one-way ANOVA followed by Tukey's HSD post hoc test to compare results between groups were utilized.

Results

The crude extract demonstrated significant antipyretic potential (P<0.05 by 100 mg/kg and 200 mg/kg as well as P<0.01 by 400 mg/kg), with a maximum of 95.06% reduction in rectal temperature at 400 mg/kg, comparable to 98.37% at 2.5 hours by the standard drug. Similarly, all doses of the aqueous fraction, as well as 200 mg/kg and 400 mg/kg doses of the ethyl acetate fractions, resulted in a significant (P<0.05) reduction in rectal temperature when compared to the corresponding value of the negative control group.

Conclusion

Extracts of B. abyssinica leaves were found to have a significant antipyretic effect. Thus, the use of the plant for pyrexia in traditional settings has scientific ground.

Succinimido–Ferrocidiphenol Complexed with Cyclodextrins Inhibits Glioblastoma Tumor Growth In Vitro and In Vivo without Noticeable Adverse Toxicity

SuccFerr (N-[4-ferrocenyl,5-5-bis (4-hydroxyphenyl)-pent-4-enyl]-succinimide) has remarkable antiproliferative effects in vitro, attributed to the formation of a stabilized quinone methide. The present article reports in vivo results for a possible preclinical study. SuccFerr is lipophilic and insoluble in water, so the development of a formulation to obviate this inconvenience was necessary. This was achieved by complexation with randomly methylated cyclodextrins (RAMEßCDs). This supramolecular water-soluble system allowed the in vivo experiments below to proceed. Application of SuccFerr on the glioblastoma cancer cell line U87 indicates that it affects the cellular cycle by inducing a blockade at G0/G1 phase, linked to apoptosis, and another one at the S phase, associated with senescence. Using healthy Fischer rats, we show that both intravenous and subcutaneous SuccFerr: RAMEßCD administration at 5 mg/kg lacks toxic effects on several organs. To reach lethality, doses higher than 200 mg/kg need to be administered. These results prompted us to perform an ectopic in vivo study at 1 mg/kg i.v. ferrocidiphenol SuccFerr using F98 cells xenografted in rats. Halting of cancer progression was observed after six days of injection, associated with an immunological defense response linked to the active principle. These results demonstrate that the properties of the selected ferrocidiphenol SuccFerr transfer successfully to in vivo conditions, leading to interesting therapeutic perspectives based on this chemistry.

Suppressive, curative, and prophylactic potentials of an antimalarial polyherbal mixture and its individual components in Plasmodium berghei-Infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria remains one of the most prevalent infectious diseases in tropical regions of the world, particularly in sub-Saharan Africa, where it remains epidemiologically holoendemic. The absence of effective vaccines and Plasmodium resistance to antimalarial drugs have been the major challenges to malaria control measures. An alternative strategy could be the application of validated and standardized herbal formulations.

AIM OF THE STUDY

To evaluate the antimalarial activity of a polyherbal mixture (APM) and compare it to those of its individual constituent plants.

METHODS

APM consisted of stem barks of Mangifera indica (MI), Azadirachta indica (AI), Nauclea latifolia (and roots, NL) and roots of Morinda lucida (ML). Dihydroartemisinin-piperaquine (DHP) and pyronaridine-artesunate (PA) served as positive controls. Antimalarial activity was evaluated using suppressive, curative and prophylactic assays in mice infected with Plasmodium berghei.

RESULTS

All the herbal mixtures, individually and in combination, showed significant (p < 0.05) antiplasmodial activities in the various assays. They produced considerable parasite suppression (>50%), substantial clearance (>70%), and notable prophylaxis (>60%, except for NL: 35%). APM (95.4-98.7%) and AI (92%), respectively, elicited greater and comparable suppression relative to DHP (88%) and PA (87.3%). However, all the herbal decoctions, individually (72-93.6%) and in combination (82.5-91%), showed lower parasite clearance than DHP (100%) and PA (99.5%). Meanwhile, APM showed relatively greater suppression and prophylaxis than its constituent plants, suggesting that the combination produced synergistic or additive effects.

CONCLUSION

These findings could substantiate the use of these plants, singly or in combination, as traditional remedies for malaria. Further studies are recommended to evaluate their clinical usefulness.

Protective Effects of Anthocleista djalonensis Extracts against Pentylenetetrazole-Induced Epileptic Seizures and Neuronal Cell Loss: Role of Antioxidant Defense System

Oxidative stress and neurodegeneration are involved in the initiation of epileptogenesis and progression of epileptic seizures. This study was aimed at investigating the anticonvulsant, antioxidant, and neuroprotective properties of active fractions isolated from Anthocleista djalonensis root barks in pentylenetetrazole mouse models of epileptic seizures. Bioactive-guided fractionation of Anthocleista djalonensis (AFAD) extracts using acute pentylenetetrazole (90 mg/kg) induced generalised tonic-clonic seizures, which afforded a potent anticonvulsant fraction (FPool 5). Further fractionation of AFAD was performed by high-performance liquid chromatography, which yielded fifteen subfractions, which were chemically characterised. In addition, AFAD was tested against convulsions or spontaneous kindled seizures induced, respectively, by acute (50 mg/kg) or subchronic (30 mg/kg) injection of pentylenetetrazole. Finally, oxidative stress markers, brain GABA content, and neuronal cell loss were evaluated in AFAD-treated pentylenetetrazole-kindled mice. Administration of AFAD significantly protected mice against acute pentylenetetrazole (90 mg/kg)-induced convulsions. In acute pentylenetetrazole (50 mg/kg)-induced hippocampal and cortical paroxysmal discharges, AFAD significantly decreased the number of crisis, the cumulative duration of crisis, and the mean duration of crisis. Additionally, AFAD significantly decreased the number of myoclonic jerks and improved the seizure score in subchronic pentylenetetrazole-induced kindled seizures. The pentylenetetrazole-induced alteration of oxidant-antioxidant balance, GABA concentration, and neuronal cells in the brain were attenuated by AFAD treatment. This study showed that AFAD protected mice against pentylenetetrazole-induced epileptic seizures possibly through the enhancement of antioxidant defence and GABAergic signalling. These events might be correlated with the amelioration of neuronal cell loss; hence, AFAD could be a potential candidate for the treatment of epilepsy.

Black-box modelling, bi-objective optimization and ASPEN batch simulation of phenolic compound extraction from Nauclea latifolia root

Nauclea latifolia root (NLR) extract is one of phytochemicals used to treat various ailments in most of developing countries. This investigation focuses on modelling, optimization and computer-aided simulation of phenolic solid-liquid extraction from NLR. The extraction experiments were conducted at extraction temperature (ET: 33.79–76.21 °C), process time (PT: 2.79–4.21 h) and solid-liquid ratio (SLC: 0.007929–0.018355 g/ml). Regression models (RM) were developed, using Response Surface Methodology (RSM) in Design Expert software, for predicting and optimizing total phenolic content (TPC) and total flavonoid content (TFC) and also compared with adaptive neuro-fuzzy inference system (ANFIS) modelling in Matlab environment. Aspen Batch Process Developer (ABPD) V10 was used to simulate phenolic extract production and perform material balance of the process. Both Coefficients of determination (R²) of RSM (TFC: 0.9996, TPC: 0.9932) and ANFIS models (TFC: 0.99998, TPC: 0.9982) were compared and predicted satisfactorily. Optimization results show: ET (2.79 h), PT (38.8 °C), SLC (0.0198 g/ml), TFC (25.92 25.92 μg RE/g) and TPC (8.47 mg GAE/g). The phenolic extraction base case simulation results gave batch throughput, annual throughput, number of batches per year 0.0089 g/batch, 0.139 g/year and 1019 batches, respectively. The ABPD predicted TPC and experimental TPC results were compared and gave mean relative deviation error of 3.75%. Thus, ABPD simulation model is reasonably reliable for the scale-up design engineering of the phenolic extract production from NLR.

Therapeutic Uses of Red Macroalgae

Red Seaweed “Rhodophyta” are an important group of macroalgae that include approximately 7000 species. They are a rich source of structurally diverse bioactive constituents, including protein, sulfated polysaccharides, pigments, polyunsaturated fatty acids, vitamins, minerals, and phenolic compounds with nutritional, medical, and industrial importance. Polysaccharides are the main components in the cell wall of red algae and represent about 40–50% of the dry weight, which are extensively utilized in industry and pharmaceutical compounds, due to their thickening and gelling properties. The hydrocolloids galactans carrageenans and agars are the main red seaweed cell wall polysaccharides, which had broad-spectrum therapeutic characters. Generally, the chemical contents of seaweed are different according to the algal species, growth stage, environment, and external conditions, e.g., the temperature of the water, light intensity, nutrient concentrations in the ecosystem. Economically, they can be recommended as a substitute source for natural ingredients that contribute to a broad range of bioactivities like cancer therapy, anti-inflammatory agents, and acetylcholinesterase inhibitory. This review touches on the main points of the pharmaceutical applications of red seaweed, as well as the exploitation of their specific compounds and secondary metabolites with vital roles.

Pharmacological evaluation of analgesic, anti-inflammatory and antipyretic activities of ethanolic extract of Indigofera argentea Burm. f

ETHNOPHARMACOLOGICAL RELEVANCE

Indigofera argentea Burm. f.; commonly known as neel, jantari, hathio; is traditionally used for the treatment of headache, fever, inflammation and body pain. Local communities also used this plant for the treatment of malaria, jaundice, vertigo and gastric disorders.

AIM OF THE STUDY

This study is aimed to evaluate the toxicity and possible analgesic, anti-inflammatory and antipyretic activities of the ethanolic crude extract of Indigofera argentea (IaCr) to support its use in folk medicine and to screen the phytochemical constituents and antioxidant activity.

MATERIALS AND METHODS

Aqueous ethanolic (30:70) extract of whole plant of Indigofera argentea (IaCr) was prepared and phytochemical study was performed by preliminary methods followed by HPLC and DPPH method. In vivo experiments were performed in Wistar albino rats including hot plate, tail immersion, formalin and capsaicin-induced pain tests in rats and acetic acid-induced writhing test in mice. Anti-inflammatory activity was assessed by using in vitro human red blood cell (HRBC) membrane stabilization and carrageenan-induced rat paw edema test, while antipyretic activity was evaluated by Brewer's yeast-induced pyrexia test.

RESULTS

The crude extract of Indigofera argentea confirmed the presence of flavonoids, glycosides, alkaloids, saponins and tannins as soluble ethanolic constituents in preliminary study. The maximum quantity of gallic acid equivalent (GAE) phenolics, and quercetin equivalent (QE) flavonoid content found was 81 ± 2 mg GAE/g and 56 ± 1.4 mg QE/g of extract respectively. Quantification based on HPLC exposed the presence of phenols and flavonoids, quercetin, gallic acid, caffeic acid, chlorogenic acid, benzoic acid, ferulic acid and coumaric acid. In vivo experiments revealed significant P < 0.05) dose-dependent inhibition in hot plate, tail immersion and capsaicin-induced pain test. IaCr showed significant inhibition of pain latency against both phases in formalin test and considerably decreased the number of writhes caused by acetic acid at the doses of 30, 100 and 300 mg/kg. In the in vitro anti-inflammatory (HRBC) assay, IaCr showed good membrane stability with maximum percentage hemolysis inhibition of 49.29% while in carrageenan-induced paw edema test in rats the IaCr showed significant anti-inflammatory action in a dose-dependent fashion. Statistical significant reduction in rectal temperature was observed at the doses of 100 and 300 mg/kg in yeast-induced pyrexia test in rats.

CONCLUSION

The results of the experimental studies proved the analgesic, anti-inflammatory and antipyretic activities of Indigofera argentea and supported the traditional use of this plant.

Effects of Treatment with Nauclea latifolia Root Decoction on Sexual Behavior and Reproductive Functions in Male Rabbits

Nauclea latifolia is used in traditional medicine for the treatment of male reproductive diseases. Despite its vast uses, its effects on the male reproductive system have not been scientifically proven. This study aimed to investigate the effects of Nauclea latifolia root decoction on sexual behavior and functions in male rabbits. Twenty-four male rabbits were divided into four groups: The first group received daily distilled water orally. The second, third, and fourth groups were orally treated with 100, 200, and 400 mg/kg body weight of Nuclea latifolia root, respectively. Sexual behavior parameters were carried out on weeks 1, 2, and 3 of the study. Testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured from the serum, while the testes tissue samples were used for antioxidant and histopathological examinations. Treatment with 200 and 400 mg/kg body weight resulted in significantly (p < .05) increased frequencies of mounting and intromission. In addition, the ejaculation latency was significantly prolonged (p < .05). The latencies of mounting and intromission were significantly decreased (p < .05), whereas ejaculation frequency increased. Serum testosterone, FSH, and LH increased significantly (p < .05) after treatment with Nuclea latifolia. There was an increase in epididymal sperm counts at 200 and 400 mg/kg body weight doses compared to the control. The extract also increased sperm motility and viability and improved testicular oxidative status. Histological examination revealed an increase in germinal layer thickness. The present study suggests that treatment with N. latifolia improves male sexual function and fertility and protects the testes from oxidative damage.

Analgesic, anti-inflammatory and anti-arthritic properties of aqueous and methanolic stem bark extracts from Nauclea pobeguinii (Rubiacee) in rats

Background Nauclea pobeguinii is a plant species found in the centre region of Cameroon. The stem bark of this plant is traditionally used to ease pain and cure inflammation. Method This study was undertaken to evaluate the effects of doses 150 and 300 mg/kg of the aqueous and methanolic stem bark extracts from Nauclea pobeguinii on acute pain, acute and chronic inflammation induced by formalin and arthritis induced by zymosan A in rats. Oxidative stress parameters such as catalase, malondialdehyde and nitric oxide were measured in rats subjected to chronic inflammation. The standard used was diclofenac at 5 mg/kg. Results Aqueous extract as well as methanolic extract of Nauclea pobeguinii led to a significant reduction in the second phase of formalin induced pain with 54.22 and 48.02% of inhibition percentage, respectively. The formalin-induced inflammatory oedema was reduced by both extracts, and this effect remains significant until the tenth day of treatment. Equally, extracts significantly increased the catalase activity and inhibited the production of malondialdehyde (MDA) in serum, brain and spinal cord and NO reduction only in serum. Both extracts significantly reduced the articular oedema induced by zymosan A for 6 h and for 5 days. Furthermore, the histological study of the articulations shows a non-altered synovial membrane and a small cartilage in all treated animals versus negative control group. Conclusions From these results, it can be concluded that pain, inflammation and arthritic healing activities of both stem bark extracts were expressed in rats and could conciliate the use of this vegetable by traditional African healers.

A novel triterpenoid 16-hydroxy betulinic acid isolated from Mikania cordata attributes multi-faced pharmacological activities

The aerial parts of extensively used ethnomedicinal plant Mikania cordata (Burm. f.) Robinson growing wild in Bangladesh were investigated to isolate and characterize compounds responsible for the bioactivities of the plant. In the present study, a new derivatives of betulinic acid, 16-hydroxy betulinic acid [3β,16-dihydroxy-lup-20(29)-en-28-oic] was isolated and the structure of the compound was determined by NMR spectroscopic means and comparing with available literature data. The isolated compound was then investigated for different pharmacological activities including antibacterial, antifungal, analgesic, anti-inflammatory and antipyretic potential employing different methods. The compound showed potent antibacterial activity with inhibition zone of diameter ranging from 12.0 to 17.5 mm and antifungal activity with mycelial growth inhibition ranging from 37.6 to 54.5%. The MIC values for antibacterial and antifungal activities ranged from 31.5–125 and 250–1000 μg/mL respectively. The compound (50 and 100 mg/kg body weight) showed potent peripheral and central analgesic activity with 55.19% and 41% of writhing inhibition at 90 min after administration of the compound and the highest 55.98%, 79.18% elongation of reaction time, respectively. In anti-inflammatory activity screening, the compound (100 mg/kg b.w.) revealed the highest 77.08% edema inhibition at 4 h after administration of carrageenan. In antipyretic assay, 16-hydroxy betulinic acid displayed a strong antipyretic effect in yeast-induced rats. From the present study it is apparent that 16-hydroxy betulinic acid might play vital role to establish M. cordata as ethnomedicinal plant to treat wound, cuts and fever.

Investigation of nepetolide as a novel lead compound: Antioxidant, antimicrobial, cytotoxic, anticancer, anti-inflammatory, analgesic activities and molecular docking evaluation

In the present study, we describe various pharmacological effects and computational analysis of nepetolide, a tricyclic clerodane-type diterpene, isolated from Nepeta suavis. Nepetolide concentration-dependently (1.0-1000 µg/mL) exhibited 1,1-diphenyl,2-picrylhydrazyl free radical scavenging activity with maximum effect of 87.01 ± 1.85%, indicating its antioxidant potential, as shown by standard drug, ascorbic acid. It was moderately active against bacterial strain of Staphylococcus aureus. In brine shrimp's lethality model, nepetolide potently showed cytotoxic effect, with LC50 value of 8.7 µg/mL. When evaluated for antitumor activity in potato disc tumor assay, nepetolide exerted tumor inhibitory effect of 56.5 ± 1.5% at maximum tested concentration of 1000 µg/mL. Nepetolide at 20 mg/kg reduced carrageenan-induced inflammation (P < .001 vs. saline group) in rat paw. Nepetolide dose-dependently (100-500 mg/kg) decreased acetic acid evoked writhes, as exhibited by diclofenac sodium. In-silico investigation of nepetolide was carried out against cyclooxygenase-2, epidermal growth factor receptor and lipoxygenase-2 targets. Virtual screening through Patchdock online docking server identified primarily hydrophobic interactions between ligand nepetolide and receptors proteins. Enhanced hydrogen bonding was predicted with Autodock showing 6-8 hydrogen bonds per target. These results indicate that nepetolide exhibits antioxidant, antibacterial, cytotoxic, anticancer, anti-inflammatory and analgesic activities and should be considered as a lead compound for developing drugs for the remedy of oxidative stress-induced disorders, microbial infections, cancers, inflammations and pain.

Traditional uses, phytochemistry and pharmacological properties of African Nauclea species: A review

ETHNOPHARMACOALOGICAL RELEVANCE

The genus Nauclea in Africa comprises seven species. Among them, N. latifolia, N. diderrichii and N. pobeguinii are widely used by the local population in traditional remedies. Preparation from various parts of plants (e.g. roots, bark, leaves) are indicated by traditional healers for a wide range of diseases including malaria, pain, digestive ailments or metabolic diseases.

MATERIALS AND METHODS

A literature search was conducted on African species of the genus Nauclea using scientific databases such as Google Scholar, Pubmed or SciFinder. Every document of ethnopharmacological, phytochemical or pharmacological relevance and written in English or French were analyzed.

RESULTS AND DISCUSSION

The Nauclea genus is used as ethnomedicine all along sub-Saharan Africa. Several local populations consider Nauclea species as a major source of remedies for malaria. In this regard, two improved traditional medicines are currently under development using extracts from N. latifolia and N. pobeguinii. Concerning the chemical composition of the Nauclea genus, indoloquinolizidines alkaloids could be considered as the major class of compounds as they are reported in every analyzed Nauclea species, with numerous structures identified. Based on traditional indications a considerable amount of pharmacological studies were conducted to ensure activity and attempt to link them to the presence of particular compounds in plant extracts.

CONCLUSION

Many experimental studies using plant extracts of the African species of the genus Nauclea validate traditional indications (e.g. malaria and pain). However, bioactive compounds are rarely identified and therefore, there is a clear need for further evaluations as well as for toxicity experiments. The sustainability of these plants, especially of N. diderrichii, a threatened species, should be kept in mind to adapt local uses and preparation modes of traditional remedies.

Anticonvulsant activity of an active fraction extracted from Crinum jagus L. (Amaryllidaceae), and its possible effects on fully kindled seizures, depression-like behaviour and oxidative stress in experimental rodent models

ETHNOPHARMACOLOGICAL RELEVANCE

The leaf extract of Crinum jagus L. (Amaryllidaceae) is widely used in traditional Cameroonian medicine as antiepileptic remedy and for the treatment of convulsion, depression and mood disorders associated with epilepsy.

AIM OF THE STUDY

Hence, this study was conducted to evaluate the effects of an active fraction extracted from the leaves of Crinum jagus against seizures, depression-like behaviour and oxidative stress in pentylenetetrazole (PTZ)-induced kindling in mice.

MATERIALS AND METHODS

Bioactive-guided fractionation of the leaf extract of Crinum jagus by using 70mg/kg PTZ-induced convulsions in mice, afforded a potent anticonvulsant fraction (flavonol kaempferol; C4.4). The effects of C4.4 on 30mg/kg PTZ-induced kindling, kindling-induced depression like-behaviour and oxidative stress was evaluated. Mice were injected PTZ (30mg/kg, i.p.) once every alternate day (48±1h) until the development of kindling. Depression was assessed using tail suspension test and forced swim test while the oxidative stress parameters were estimated in the whole brain at the end of experiments. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of C4.4. Acute toxicity of C4.4 was also assessed in mice.

RESULTS

Convulsions-induced by 70mg/kg PTZ were strongly antagonized by C4.4. Oral administration of C4.4 significantly increased the latency to myoclonic jerks, clonic seizures as well as generalized tonic-clonic seizures, improved the seizure mean stage and decreased the number of myoclonic jerks in PTZ-kindled mice. The data indicated also that C4.4 significantly reduced the immobility times in the tail suspension test and the forced swim test. This active fraction has also antioxidant properties by decreasing the lipid peroxidation, and augmenting endogenous antioxidant enzymes in brain. C4.4 administered (12.5-50mg/kg) did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to C4.4 at the therapeutic doses.

CONCLUSION

These results suggest that pretreatment with C4.4 ameliorates convulsions-induced by PTZ, protects mice against kindling development, depression-like behaviour and oxidative stress in PTZ-kindled mice. These finding provides scientific rationale for the use of Crinum jagus extracts for the amelioration of epilepsy observed in traditional medicine in Cameroon.

Anticonvulsant effects of iridoid glycosides fraction purified from Feretia apodanthera Del. (Rubiaceae) in experimental mice models of generalized tonic-clonic seizures

Background

Despite the increasing number and variety of antiepileptic drugs, nearly 30 % of epileptic patients who receive appropriate medical attention have persisting seizures. Anticonvulsant activity has been demonstrated for different iridoid glycoside-rich plant extracts. This study was designed to investigate the anticonvulsant effects of iridoid glycosides purified from Feretia apodanthera and to explore the possible mechanisms involved in antiepileptic activity.

Methods

The anticonvulsant effects of iridoid glycosides extracts were investigated against 2.7 mg/kg bicuculline- and 70 mg/kg pentylenetetrazole-induced convulsions. The behavioural and electroencephalographic manifestations of 50 mg/kg pentylenetetrazole-induced seizures in mice as a model of generalized tonic-clonic seizures were also evaluated. Finally, the extracts were tested on the course of kindling development, kindled-seizures and oxidative stress markers in 30 mg/kg pentylenetetrazole-kindled mice. Their effects on brain GABA content were also determined.

Results

The iridoid glycosides (30–90 mg/kg) protected mice against bicuculline-induced motor seizures in all pre-treated animals. Behavioural seizures- and mortality-induced by 70 mg/kg pentylenetetrazole were strongly antagonized by the extracts (60–90 mg/kg). The number of crisis (n/20 min), the cumulative duration of crisis (sec/20 min), and the mean duration of crisis (sec) recorded in 50 mg/kg pentylenetetrazole-treated mice were significantly decreased in all pre-treated mice with the extracts (60–90 mg/kg). Administration of the extracts (30–90 mg/kg) significantly increased the latency to myoclonic jerks, clonic seizures as well as generalized tonic-clonic seizures, improved the seizure mean stage and decreased the number of myoclonic jerks in 30 mg/kg pentylenetetrazole-kindled mice. Pentylenetetrazole kindling induced significant oxidative stress and brain GABA content alteration that was reversed by pretreatment with the extracts in a dose-dependent manner.

Conclusions

The results indicate that pretreatment with the iridoid glycosides extracts of Feretia apodenthera improves generalized tonic-clonic seizures-induced by chemo-convulsants, protects mice against kindling development and oxidative stress, and improves brain GABA content in pentylenetetrazole-kindled mice.

Nauclea latifolia: biological activity and alkaloid phytochemistry of a West African tree

Covering up to 2016Nauclea latifolia (syn. Sarcocephalus latifolius, Rubiaceae), commonly called the African pincushion tree, is a plant widely used in folk medicine in different regions of Africa for treating a variety of illnesses, including malaria, epilepsy and pain. N. latifolia has not only drawn the interest of traditional healers but also of phytochemists, who have identified a range of bioactive indole alkaloids in its tissue. More recently, following up on the traditional use of extracts in pain management, a bio-guided purification from the roots of the tree led to the identification of the active ingredient as tramadol, available as a synthetic analgesic since the 1970s. The discovery of this compound as a natural phytochemical was highlighted worldwide. This review focuses on the correlation between extracted compounds and pharmacological activities, paying special attention to infectious diseases and neurologically-related disorders. A critical analysis of the data reported so far on the natural origin of tramadol and its proposed biosynthesis is also presented.

Acute and sub-chronic toxicity studies of three plants used in Cameroonian ethnoveterinary medicine: Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) leaves, Carica papaya L. (Caricaceae) seeds or leaves, and Mimosa pudica L. (Fabaceae) leaves in Kabir chicks

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm. f. (Xanthorrhoeaceae), Carica papaya L. (Caricaceae) and Mimosa pudica L. (Fabaceae) are widely used in the Cameroonian ethnoveterinary medicine as a panacea, and specifically for gastrointestinal disorders as well as an anthelmintic and antibacterial.

AIM OF THE STUDY

The present study evaluated the potential toxicity of the hydroalcoholic extracts of Aloe vera leaves, Carica papaya leaves or seeds, and Mimosa pudica leaves after acute and sub-chronic administration in chicks.

MATERIALS AND METHODS

For the acute toxicity test a single administration of each of the four hydroalcoholic extracts was given orally at doses ranging from 40 to 5120 mg/kg (n=5/group/sex). In the sub-chronic study, these extracts were given orally as a single administration to chicks at doses of 80, 160, 320 and 640 mg/kg/day for 42 days. The anti-angiogenic properties of these extracts (5-320 µg/mg) were investigated in the chick chorioallantoic membrane in vivo.

RESULTS

In the acute toxicity test, none of the four studied hydroalcoholic extracts induced mortality or significant behavioural changes. The sub-acute treatment with the four plant extracts did not alter either the body weight gain or the food and water consumption. However, the results indicated that Aloe vera leaf extract acute treatment by oral route at doses up to 2560 mg/kg did not produce death in 50% (5/10) of chicks during 24h or 14 days of observation, but 20% (2/10) chicks died. The haematological and biochemical analyses did not show significant differences in any of the parameters examined in female or male groups, with the exception of a transient rise in white blood cell counts at high doses (640 mg/kg). Additionally, these extracts did not have the potential for anti-angiogenic effects through the inhibition of neo-angiogenesis in the chick chorioallantoic membrane in vivo.

CONCLUSION

The results showed that the therapeutic use of the hydroalcoholic extracts of Aloe vera leaves, Carica papaya leaves or seeds and Mimosa pudica leaves had very low toxicity in oral acute high dose administration and no toxicity in oral sub-chronic low dose administration and indicate that the plants could be considered safe for oral medication in chicks.

Antinociceptive activity of Euadenia trifoliolata (Schum. & Thonn.) Oliv. leaves and roots in mice

The leaves and roots of Euadenia trifoliolata are used in Nigeria traditional medicine for the treatment of ear ache, head ache and inflammation. The aim of the study was to evaluate the antinociceptive activity of ethanolic extract of the leaves (EL) and roots (ER) of E. trifoliolata in mice. Oral toxicity testing was performed using OECD guidelines. Antinociceptive effect was studied in mice using acetic acid-induced writhing, formalin, tail immersion and hot plate tests. Total polyphenolic contents were determined using standard methods. No mortality was recorded 24 h after oral administration of both EL and ER up to 5000 mg/kg. At the dose of 50, 100 and 200 mg/kg, administration of EL and ER resulted in significant reduction in the number of writhes compared to control. The percentage inhibition of writhings was calculated as 35.67%, 46.71% and 67.94% (EL) and 55.41%, 57.32% and 72.61% (ER), respectively. In hot plate test, EL and ER showed statistically significant antinociceptive effect, although low percentage inhibition (<50%) was recorded for ER at all the doses tested. Only EL (100 and 200 mg/kg) significantly (p < 0.001) increased the reaction time in tail immersion test. Both extracts significantly (p < 0.001) reduced the licking time in both phases of formalin test compared to control. The content of total phenolic, flavonoid and proanthocyanidin varies between the two extracts and may be the basis of the observed antinociceptive effect. The results indicate antinociceptive activity for the leaves and roots of E. trifoliolata, with the extract of the leaves showing better activity.

Qualitative phytochemical screening and evaluation of anti-inflammatory, analgesic and antipyretic activities of Microcos paniculata barks and fruits

OBJECTIVE

The main objectives of this study were to qualitatively evaluate the profile of phytochemical constituents present in methanolic extract of Microcos paniculata bark (BME) and fruit (FME), as well as to evaluate their anti-inflammatory, analgesic and antipyretic activities.

METHODS

Phytochemical constituents of BME and FME were determined by different qualitative tests such as Molisch's test, Fehling's test, alkaloid test, frothing test, FeCl3 test, alkali test, Salkowski's test and Baljet test. The anti-inflammatory, analgesic and antipyretic activities of the extracts were evaluated through proteinase-inhibitory assay, xylene-induced ear edema test, cotton pellet-induced granuloma formation in mice, formalin test, acetic acid-induced writhing test, tail immersion test and Brewer's yeast-induced pyrexia in mice.

RESULTS

M. paniculata extracts revealed the presence of carbohydrates, alkaloids, saponins, tannins, flavonoids and triterpenoids. All of the extracts showed significant (P<0.05, vs aspirin group) proteinase-inhibitory activity, whereas the highest effect elicited by plant extracts was exhibited by the BME (75.94% proteinase inhibition activity) with a half-maximal inhibitory concentration (IC50) of 61.31 μg/mL. Each extract at the doses of 200 and 400 mg/kg body weight showed significant (P<0.05, vs control) percentage inhibition of ear edema and granuloma formation. These extracts significantly (P<0.05, vs control) reduced the paw licking and abdominal writhing of mice. In addition, BME 400 mg/kg, and FME at 200 and 400 mg/kg showed significant (P<0.05, vs control) analgesic activities at 60 min in the tail immersion test. Again, the significant (P<0.05, vs control) post-treatment antipyretic activities were found by BME 200 and 400 mg/kg and FME 400 mg/kg respectively.

CONCLUSION

Study results indicate that M. paniculata may provide a source of plant compounds with anti-inflammatory, analgesic and antipyretic activities.

Quali-quantitative analysis of best selling drugs from pharmacy, street market and traditional herbal medicine: a pilot study of market surveillance in Senegal

A pilot study of market surveillance in Senegal has been performed analyzing best selling drugs from an official pharmacy and a street market in two principal cities of Senegal and some traditional preparations from herbal medicine from the same market. A simple and rapid gas chromatography method with mass spectrometry detection has been applied after a liquid-liquid extraction of pharmaceutical products and traditional preparations at acidic, neutral and basic pH with chloroform-isopropanol (9:1, v/v). The assay was validated in the range from 10mg to 250 mg/g powder preparations with good determination coefficients (r(2)≥ 0.99) for the calibration curves. At three concentrations spanning the linear dynamic ranges of the calibration curves, mean recoveries of substances under investigation were always higher than 90% and intra-assay and inter-assay precision and accuracy were always better than 15%. The four best selling drugs purchased from a Dakar local pharmacy exactly contained the amount of active principles reported in the respective labels while the best selling drugs freely purchased from Kaolack market contained an amount of active ingredients lower than that declared on the label. No pharmacological active compound, but salicylic acid was found in one of the traditional herbal preparations. This pilot study showed that whereas official drugs sold in pharmacies at prices accessible for a very few portion of the population contained the amount of active principles as reported in the labels, those from street market bought by the majority of population contained an amount of active ingredients lower than that declared on the label and finally traditional herbal preparations seldom contain pharmacological active principles.

In vitro study on the antioxidant potentials of the leaves and fruits of Nauclea latifolia

This study was carried out to investigate the in vitro antioxidant potentials of the leaves and fruits of Nauclea latifolia, a straggling shrub or small tree, native to tropical Africa and Asia. Hot water extracts of the leaves and fruits of Nauclea latifolia were assessed for their total polyphenolic, flavanol, and flavonol contents as well as 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, ferric reducing antioxidant power (FRAP), Trolox equivalence antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays. The aqueous extract of the leaves was found to contain higher level of total polyphenols (11.63 ± 0.023 mg GAE/g), flavanol (1.45 ± 0.10 mg CE/g), and flavonol (2.22 ± 0.37 mg QE/g) than the extract of the fruits with values of 1.75 ± 0.02 mg GAE/g (total polyphenol), 0.15 ± 0.01 mg CE/g (flavanol), and 1.00 ± 0.13 mg QE/g (flavonol). Similarly, the aqueous extract of the leaves also exhibited higher DPPH (IC50 20.64 mg/mL), FRAP (86.10 ± 3.46 μmol AAE/g), TEAC (94.83 ± 3.57 μmol TE/g), and ORAC (196.55 ± 0.073 μmol TE/g) than the extract of the fruits with DPPH (IC50 120.33 mg/mL), FRAP (12.23 ± 0.40 μmol AAE/g), TEAC (12.48 ± 0.21 μmol TE/g), and ORAC (58.88 ± 0.073 μmol TE/g). The present study showed that Nauclea latifolia has strong antioxidant potentials with the leaves demonstrating higher in vitro antioxidant activities than the fruits.

Sub-acute effects of ethanol extract of Sarcocephalus latifolius root on some physiologically important electrolytes in serum of normal Wistar albino rats

Sarcocephalus latifolius (Synonym, Nauclea latifolia) is a shrub commonly seen in the South East of Nigeria. It is widely applied as herbal remedy in the treatment of various illnesses. The effect of ethanol extract of the root of the plant on some serum electrolytes was studied. A total of thirty Wistar albino rats were used to determine serum concentrations of K+, Ca2+, Cl- and HCO3-. The animals were divided into six groups of five rats each. Five groups labeled A, B, C, D and E, were administered orally with graded doses of root extract of Sarcocephalus latifolius at concentration of 300, 350, 400, 450 and 500 mg kg(-1) body weight, respectively. The sixth group (Group F) was used as the control and its animals were simply sustained on normal diet and water. Administration of the extract lasted for twenty-one days after which the animals were sacrificed by cardiac puncture. K+, Ca2+, Cl- and HCO3- were determined from each sample and the mean concentration was calculated for each dose and the control. Potassium, calcium and chloride determination were done by colorimetric methods while determination of bicarbonate concentration was done by simple titration. Na+ was separately assayed, by flame photometer, from a set of 18 rats of six animals in each of three groups. For K+, non dose dependent increases were observed which was non-significant (p > 0.05), for A, D and E but significant (p < 0.05) for B and C. Ca2+ showed a dose dependent and significant (p < 0.05) decreases, except for A (p > 0.05). Decreases (p < 0.05) for C, D, E and (p > 0.05) for A and B were observed for Cl-. Serum bicarbonate appeared almost completely unaffected by the extract, showing no significant changes. Na+ levels were depressed for the two test groups, A and B compared with the control (group C), with test group B showing a significant decrease (p < 0.05). From the analysis, it could be concluded that Sarcocephalus latifolius has the capacity to influence various electrolytes to physiologically important degrees. Significant reductions in sodium and calcium levels indicate the usefulness of the plant in treatment of hypertension and pain/fever, respectively. However, significant reductions in chloride may negatively affect the normal balance of fluid in the body. Therefore, more scientific research is needed to establish the best approach to optimizing the numerous medicinal potentials of the plant.

Nauclea latifolia Smith (Rubiaceae) exerts antinociceptive effects in neuropathic pain induced by chronic constriction injury of the sciatic nerve

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Nauclea latifolia Smith (Rubiaceae) popularly known as "koumkouma" is used in traditional Cameroonian medicine as neuropathic pain remedy and for the treatment of headache, inflammatory pain and convulsion. This study was conducted to evaluate the antinociceptive effects of the alkaloid fraction isolated from Nauclea latifolia in neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in rat.

MATERIALS AND METHODS

Bioactive-guided fractionation of the root extracts of Nauclea latifolia using the Von Frey in a rat model of neuropathic pain (Benett model), afforded a potent anti-hyperalgesic fraction IV. Further fractionation of this fraction was performed by high-performance liquid chromatography (HPLC), yielded eight sub-fractions (F1-F8) which were tested for antinociceptive effects. The alkaloid fraction (F3) collected by HPLC, exhibited potent antinociceptive effects, and the anti-allodynic and anti-hyperalgesic effects of this fraction (8, 16, 40 and 80 mg/kg) were determined using the von Frey and acetone tests respectively in a rat model of neuropathic pain. Rota-rod performance and catalepsy tests were used for the assessment of motor coordination.

RESULTS

The alkaloid fraction (80 mg/kg) administered intraperitoneally induced a completely decreased hyperalgesia 90 min post-dosing. In the acetone test, the Nauclea latifolia fraction at 80mg/kg showed its maximal anti-allodynic effects 120 min post-injection. The areas under the curve (AUC) of the anti-allodynic or anti-hyperalgesic effects produced by the alkaloid fraction at 80 mg/kg were significantly (p<0.001) greater than the AUC of effects produced by vehicle in CCI rats. The alkaloid fraction did not exhibit any significant effects on the spontaneous locomotor activity of the mice in rota-rod performance and no sign of catalepsy was observed.

CONCLUSION

The analysis of the effects, expressed as the time course of AUC, supports the traditional use of Nauclea latifolia in neuropathic pain therapy. The pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for this anti-hyperalgesic and anti-allodynic action and also to identify the active substances present in the roots extracts of Nauclea latifolia.

In vitro anti-Herpes simplex virus activity of crude extract of the roots of Nauclea latifolia Smith (Rubiaceae)

Background

Nauclea latifolia Smith, a shrub belonging to the family Rubiaceae is a very popular medicinal plant in Cameroon and neighboring countries where it is used to treat jaundice, yellow fever, rheumatism, abdominal pains, hepatitis, diarrhea, dysentery, hypertension, as well as diabetes. The ethno-medicinal use against yellow fever, jaundice and diarrhea prompted us to investigate on the antiviral activity of the root bark of N. latifolia. In this study, HSV-2 was chosen as a viral model because of its strong impact on HIV transmission and acquisition.

Methods

The crude extract under study was prepared by maceration of air-dried and powdered roots barks of N. latifolia in CH₂Cl₂/MeOH (50:50) mixture for 48 hours, then it was subjected to filtration and evaporation under vacuum. A phytochemical analysis of the crude extract was performed by High Performance Liquid Chromatography coupled with a photodiode array and mass spectrometry (HPLC-PDA-ESI-qMS). The anti-HSV-2 activity was assayed in vitro by plaque reduction and virus yield assays and the major mechanism of action was investigated by virucidal and time of addition assays. Data values were compared using the Extra sum of squares F test of program GraphPad PRISM 4.

Results

The main components detected in the extract belong to the class of indole alkaloids characteristic of Nauclea genus. Strictosamide, vincosamide and pumiloside were tentatively identified together with quinovic acid glycoside. N. latifolia crude extract inhibited both acyclovir sensitive and acyclovir resistant HSV-2 strains, with IC₅₀ values of 5.38 μg/ml for the former and 7.17 μg/ml for the latter. The extract was found to be most active when added post-infection, with IC₅₀ of 3.63 μg/ml.

Conclusion

The results of this work partly justify the empirical use of N. latifolia in traditional medicine for the treatment of viral diseases. This extract could be a promising rough material for the development of a new and more effective modern anti-HSV-2 medication also active against acyclovir-resistant HSV-2 strains.

Anti-hyperglycemic effects of three medicinal plants in diabetic pregnancy: modulation of T cell proliferation

Background

Populations in Africa mostly rely on herbal concoctions for their primarily health care, but so far scientific studies supporting the use of plants in traditional medicine remain poor. The present study was undertaken to evaluate the anti-hyperglycemic effects of Picralima nitida (seeds), Nauclea latifolia (root and stem) and Oxytenanthera abyssinica (leaves) commonly used, in diabetic pregnancy.

Methods

Pregnant wistar rats, rendered diabetic by multiple low injections of streptozotocin, were treated with selected plant extracts based on their antioxidant activities. Vitamin C concentrations, fatty acid compositions and phytochemical analysis of plants extracts were determined. Effect of selected plant extracts on human T cell proliferation was also analysed.

Results

All analysed plant extracts exhibited substantial antioxidant activities probably related to their content in polyphenols. Picralima nitida exhibited the highest antioxidant capacity. Ethanolic and butanolic extracts of Picralima nitida, butanolic extract of Nauclea latifolia and ethanolic extract of Oxytenanthera abyssinica significantly decreased hyperglycemia in the diabetic pregnant rats. Butanolic extract of Picralima, also appeared to be the most potent immunosuppressor although all of the analysed extracts exerted an immunosuppressive effect on T cell proliferation probably due to their linolenic acid (C18:3n-3) and/or alkaloids content. Nevertheless, all analysed plants seemed to be good source of saturated and monounsaturated fatty acids.

Conclusion

By having antioxidant, anti-hyperglycemic and immunosuppressive activities, these plants could be good candidates in the treatment of diabetes and diabetic pregnancy.

Ethnopharmacological Survey of Plants Used in the Traditional Treatment of Gastrointestinal Pain, Inflammation and Diarrhea in Africa: Future Perspectives for Integration into Modern Medicine

There is a growing need to find the most appropriate and effective treatment options for a variety of painful syndromes, including conditions affecting the gastrointestinal tract, for treating both veterinary and human patients. The most successful regimen may come through integrated therapies including combining current and novel western drugs with acupuncture and botanical therapies or their derivatives. There is an extensive history and use of plants in African traditional medicine. In this review, we have highlighted botanical remedies used for treatment of pain, diarrheas and inflammation in traditional veterinary and human health care in Africa. These preparations are promising sources of new compounds comprised of flavonoids, bioflavanones, xanthones, terpenoids, sterols and glycosides as well as compound formulas and supplements for future use in multimodal treatment approaches to chronic pain, gastrointestinal disorders and inflammation. The advancement of plant therapies and their derivative compounds will require the identification and validation of compounds having specific anti-nociceptive neuromodulatory and/or anti-inflammatory effects. In particular, there is need for the identification of the presence of compounds that affect purinergic, GABA, glutamate, TRP, opioid and cannabinoid receptors, serotonergic and chloride channel systems through bioactivity-guided, high-throughput screening and biotesting. This will create new frontiers for obtaining novel compounds and herbal supplements to relieve pain and gastrointestinal disorders, and suppress inflammation.

Endogenous opiates and behavior: 2011

This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).

Antipsychotic and sedative effects of the leaf extract of Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae) in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae) has been used as a medicine for the treatment of epilepsy, insomnia, dementia and psychotic disorders in Cameroonian traditional medicine.

AIM OF THE STUDY

This study was designed to examine whether the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum bauchiense possess antipsychotic and sedative properties in rodents.

MATERIALS AND METHODS

The rectal temperature of mice was recorded with a probe thermometer at a constant depth. Novelty-induced rearing behavior is used to evaluate a central excitatory locomotor behavior in mice. The antipsychotic effects of the extracts were assessed using the apomorphine animal model of psychosis. The catalepsy test was tested based on the ability of the leaves extracts of Crassocephalum bauchiense to alter the duration of akinesia by placing the naive mice with both forelegs over a horizontal bar. The extracts of Crassocephalum bauchiense effects were evaluated on sodium pentobarbital-induced sleeping time. In addition, gamma-aminobutyric acid concentrations in the brain treated mice were also estimated.

RESULTS

The aqueous extract and the alkaloid fraction from Crassocephalum bauchiense caused dose-dependent inhibition of novelty-induced rearing behavior, decreased the apomorphine-induced stereotypy and fighting, and had significant fall of the body temperature. The aqueous extract prolonged the sodium pentobarbital sleeping time. This prolongation was not reversed by bicuculline, a light-sensitive competitive antagonist of GABA(A) receptors complex. However, the effect of the aqueous extract on sodium pentobarbital-induced sleeping time was blocked by N-methyl-β-carboline-3-carboxamide, a partial inverse agonist of the benzodiazepine site in the GABA(A) receptor complex and flumazenil, a specific antagonist of the benzodiazepine site in the GABAA receptor complex. In biochemical experiments, the concentration of the inhibitory amino acid, gamma-aminobutyric acid, was significantly increased in the brain of animals treated with the aqueous extract of Crassocephalum bauchiense and sodium valproate.

CONCLUSIONS

The results show that the antipsychotic and sedative properties of Crassocephalum bauchiense are possibly mediated via the blockade of dopamine D-2 receptors and GABAergic activation, respectively. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for these neuropharmacological actions and also to identify the active substances present in the extracts of Crassocephalum bauchiense.

Evaluation of antinociceptive effects of Crassocephalum bauchiense Hutch (Asteraceae) leaf extract in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Crassocephalum bauchiense have long been used in traditional Cameroonian medicine for the treatment of epilepsy, pain, inflammatory disorders, arthritis and intestinal pain.

AIM OF THE STUDY

In this study, we attempted to identify the possible antinociceptive action of the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum baucheiense.

MATERIALS AND METHODS

Using acetic acid induced abdominal constrictions, formalin-, capsaisin- and glutamate-induced nociception, and hot plate assay procedures, the antinociceptive effects of the aqueous extract and the alkaloid fraction was assessed after oral administration in mice. Morphine sulfate was used as reference analgesic agent. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of the extracts of Crassocephalum bauchiense. Male and female Swiss mice were used to assess acute toxicity of these extracts.

RESULTS

The aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced a significant antinociceptive effects in the acetic acid, formalin, glutamate, capsaicin and hot plate tests. These antinociceptive effects of Crassocephalum bauchiense were significantly attenuated by pretreatment with naloxone. The extracts of Crassocephalum bauchiense did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to the aqueous extract and the alkaloid fraction, so it was not possible to calculate the LD(50).

CONCLUSION

The results confirm the popular use of Crassocephalum bauchiense as an antinociceptive, and contribute to the pharmacological knowledge of this species because it was shown that the aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced dose related antinociception in models of chemical and thermal nociception through mechanisms that involve an interaction with opioidergic pathway.