Neuropharmacological effects of the aqueous extract of Nauclea latifolia root bark in rats and mice

Neuropharmacological and antiproliferative activity of Tetrastigma leucostaphyllum (Dennst.) Alston: Evidence from in-vivo, in-vitro and in-silico approaches

As the incidence of neurodegeneration and cancer fatalities remains high, researchers are focusing their efforts on discovering and developing effective medications, especially plant-based drugs, against these diseases. Hence, this research aimed to investigate the neuropharmacological potentials of aerial parts of Tetrastigma leucostaphyllum, employing some behavioral models, while the antiproliferative effect was explored against a panel of cancer cell lines (MGC-803, A549, U-251, HeLa and MCF-7) using a colorimetric assay. In addition, active extracts were analyzed by GC-MS technique to identify the active compounds, where some selective compounds were docked with the particular pure proteins to check their binding affinity. Results from neuropharmacological research indicated that the total extract and its fractions may be effective (p = 0.05, 0.01, and 0.001, respectively) at doses of 100, 200, and 400 mg/kg of animal body weight. The greatest antidepressant and anxiolytic effects were found in the n-hexane fraction. The n-haxane fraction also exhibited the highest cytotoxicity against the U-251 cell line (IC5014.3 μg/mL), followed by the A549, MG-803, HeLa, and MCF-7 cell lines, respectively. From the n-hexane fraction, ten chemicals were detected using the GC-MS method. Additionally, the in-silico research revealed interactions between the n-hexane fractions' identified compounds and the antidepressant, anxiolytic, and cytotoxic receptors. The molecules showed binding affinities that ranged from 4.6 kcal/mol to 6.8 kcal/mol, which indicates the likelihood that they would make good drug candidates. This study highlighted the plant's neuropharmacological and cytotoxic properties, however, more research is needed to determine the etymological origin of these effects.

Effect of Nauclea subdita (Korth.) Steud. leaf extract on hematological and histopathological changes in liver and kidney of striped catfish infected by Aeromonas hydrophila

Aim

The present study was conducted to investigate the efficacy of different doses of Bangkal (Nauclea subdita) leaf extract on hematological and histological changes in kidney and liver of catfish (Pangasius hypophthalmus) infected by Aeromonas hydrophila.

Materials and Methods

Catfish were experimentally infected with A. hydrophila at a dose of 10⁸ cells/mL through intraperitoneal injection, and the hematological and histological changes in the kidney and liver of catfish against the pathogen were observed.

Results

Not all concentrations of N. subdita caused a toxic effect in striped catfish. The clinical symptoms of catfish after infection with A. hydrophila and treatment with N. subdita leaf extract included morphological and behavioral changes. N. subdita leaf extract reduced mortality caused by A. hydrophila. Treatment with N. subdita leaf extract was effective in reducing the inflammation by decreasing the activity of neutrophils, monocytes, and lymphocytes. The Hb and Ht levels of catfish significantly decreased after exposure to 10⁸ cells/mL of A. hydrophila and increased significantly after N. subdita treatment. Necrosis percentages in the kidney and liver also decrease after N. subdita treatment.

Conclusion

The results indicate that N. subdita leaf extract stimulates the immunity and increases the resistance of catfish to A. hydrophila. N. subdita leaf extract may be used as a potential source for future drug development and food applications.

Anxiolytic Action of Taurine via Intranasal Administration in Mice

Taurine has a number of beneficial pharmacological actions in the brain such as anxiolytic and neuroprotective actions. We explored to test whether taurine could be transported to the central nervous system through the intranasal route. Following intranasal administration of taurine in mice, elevated plus maze test, activity cage test and rota rod test were carried out to verify taurine's effect on anxiety. For the characterization of potential mechanism of taurine's anti-anxiety action, mouse convulsion tests with strychnine, picrotoxin, yohimbine, and isoniazid were employed. A significant increase in the time spent in the open arms was observed when taurine was administered through the nasal route in the elevated plus maze test. In addition, vertical and horizontal activities of mice treated with taurine via intranasal route were considerably diminished. These results support the hypothesis that taurine can be transported to the brain through intranasal route, thereby inducing anti-anxiety activity. Taurine's anti-anxiety action may be mediated by the strychnine-sensitive glycine receptor as evidenced by the inhibition of strychnine-induced convulsion.

In vitro antiviral activity of twenty-seven medicinal plant extracts from Southwest Nigeria against three serotypes of echoviruses

BACKGROUND

Echoviruses, a serotype of enteroviruses, infect millions of people globally and there is no specific drug treatment or vaccine available for its management. The screening of medicinal plants used locally for the treatment of infectious diseases, can provide a reliable option in the discovery of potent therapeutic compounds. This study was carried out to investigate the antiviral activities of 27 medicinal plant extracts, belonging to 26 different plant species, selected from Nigerian ethnobotany, against echovirus 7, 13 and 19 serotypes (E7, E13 and E19, respectively).

METHODS

The plants were macerated in methanol and the cytotoxicities of the crude extracts were evaluated on the rhabdomyosarcoma cell line using the MTT assay. The antiviral activity of the plant extracts and fractions against echoviruses (E7, E13, and E19) was determined using the neutralisation assay, an assay that measures the inhibition of cytopathic effect on cell culture.

RESULTS

The crude extract of Macaranga barteri leaves had the highest cytotoxicity with CC50 value of 0.27 μg/mL. This was followed by Crinum jagus (9.88 μg/mL) and Terminalia ivorensis (12.14 μg/mL). The antiviral screening showed that ten out of the 27 crude plant extracts tested were active on E7 and E19, inhibiting the cytopathic effect of the virus in tissue culture. None of the extracts inhibited the cytopathic effect caused by E13 serotype. Amongst the active plant extracts, the methanol extract of M. barteri leaves had the highest antiviral activity on both E7 and E9 with IC50 values of 0.028 and 0.0017 ng/mL, respectively, followed by the Ageratum conyzoides extract (0.208 μg/mL, E7; 0.006 μg/mL, E19) and Mondia whitei extract (0.038 μg/mL, E7; 0.005 μg/mL, E19). Amongst the fractions of M. barteri, the DCM fraction was most the active and selective on E7 (IC50 = 0.0075 ng/mL; SI = 19,896.54) and E19 (IC50 = 0.0175 ng/mL; SI = 8581.24).

CONCLUSION

Our research has demonstrated that Macaranga barteri extracts has potent antiviral activity against echoviruses E7 and E19, and our findings suggest that this extract may have potential as a therapeutic agent in the treatment of enteroviral infections.

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.

Extract of Synedrella nodiflora (L) Gaertn exhibits antipsychotic properties in murine models of psychosis

BACKGROUND

The hydro-ethanolic whole plant extract of Synedrella nodiflora (SNE) has demonstrated anticonvulsant, sedative and analgesic effects. Preliminary studies conducted in animals, SNE significantly decreased stereotypic behaviours suggesting antipsychotic potential. Coupled with the central nervous system depressant effects of SNE, we hypothesized that it may have utility in the management of psychosis. The present study therefore investigated the antipsychotic potential of the SNE in several murine models of psychosis.

METHOD

The primary central nervous system activities of SNE (30-3000 mg/kg, p.o) were investigated using the Irwin's test. The novelty-induced rearing, locomotion and stereotypy counts provoked by SNE (100-1000 mg/kg, p.o) were conducted using the open-field paradigm. The antipsychotic test models used in the screening of SNE (100-1000 mg/kg, p.o) included apomorphine-induced stereotypy, rearing, locomotion and cage climbing activities. The combined effects of a low dose of SNE (100 mg/kg) with various doses of haloperidol and chlorpromazine were analysed using the apomorphine-induced cage climbing and stereotypy, respectively. The ability of SNE to cause catalepsy in naïve mice as well as its effect on haloperidol-induced catalepsy was assessed.

RESULTS

SNE showed acetylcholine-like and serotonin-like activities in the Irwin test, with sedation occurring at high doses. SNE significantly reduced the frequencies of novelty- and apomorphine-induced rearing and locomotion; stereotypy behaviour and the frequency and duration of apomorphine-induced cage climbing in mice. In all the tests performed, SNE was less potent than the reference drugs used (chlorpromazine and haloperidol). In addition, SNE potentiated the effects of haloperidol and chlorpromazine on apomorphine-induced cage climbing and stereotypy activities in mice.

CONCLUSION

SNE, while exhibiting antipsychotic properties itself, can also potentiate the antipsychotic effects of chlorpromazine and haloperidol.

Antioxidant activity, acetylcholinesterase inhibitory potential and phytochemical analysis of Sarcocephalus latifolius Sm. bark used in traditional medicine in Sudan

BACKGROUND

Sarcocephalus latifolius is used as a traditional medicine for curing many diseases in Sudan. The main objective of the current study was to determine the antioxidant activity and acetylcholinesterase inhibition (AChEI) of S. latifolius, and to estimate its total phenolic and flavonoid contents.

METHODS

Antioxidant activity of the tested plant extracts was carried out by determining their ability to scavenge the 2,2-diphenyl-1-picryl hydrazyl (DPPH) free radical. On the other hand, AChE inhibitory activity was determined spectrophotometrically using the Ellman's colorimetric method. The levels of total phenols and flavonoids were determined quantitatively using spectrophotometric methods. MTT assay was consumed to assess the cytotoxic effect of the most active fractions. These fractions were subjected to phytochemical analysis using GC-MS techniques to determine thier chemical composition.

RESULTS

Hexane and chloroform fractions exhibited the highest antioxidant activity with IC50 values of (0.098 ± 0.08 and 0.099 ± 0.029 mg/ml) respectively. Standard propyl gallate had the lowest IC50 value of 0.0414 ± 0.11 mg/ml. The ethanolic crude extract showed low AChEI activity with 40.2 ± 0.10%. High concentrations of phenolic and flavonoid contents were observed. GCMS revealed the presence of well-known antioxidants compounds e.g. Vitamin E and caffeic acid.

CONCLUSION

The ethanolic extract of bark of S. latifolius showed potent antioxidant effects and low AChEI activity, high phenolic and flavonoid contents and presence of pharmacologically active compounds. These findings explain its wide usages in traditional medicine.

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.

An ethnobotanical survey of medicinal plants used by communities of Northern Kordofan region, Sudan

ETHNOPHARMACOLOGICAL RELEVANCE

The present study provides significant ethnopharmacological information on plant species used in North Kordofan region, western Sudan. The study was undertaken with an aim to document the medicinal uses of the species known to some Northern Kordofan communities.

MATERIAL AND METHODS

The study was conducted between 2012 and 2013. The plants were identified and voucher specimens prepared. Information was collected by means of semi-structured interviews with 258 informants (195 men and 63 women). In addition, the use value (UV) of the species was determined and the informant consensus factor (ICF) was calculated for the medicinal plants researched in the study. Further analysis was carried out to compare results with previous studies from the study area and other regions of Sudan.

RESULTS

A total of 44 plant species representing 24 families were found to be commonly used in the treatment of 73 different human health problems. The families most represented were Leguminosae (18%), Caesalpiniaceae (9%), Malvaceae (9%), Asclepiadaceae (6.8%) and Combretaceae (6.8%). The highest number of plant species are used against digestive system disorders (23 species) followed by microbial infections (21 species) and dermatology (19 species). Among all the plant parts leaves (20%), roots (19%), fruits and bark (14% each) were the most preferred plant parts used by the informants. There was strong agreement among the informants as to the usages of the plants (informant consensus factor 0.63-0.93). The most important plants on the basis of use-value were Acacia nilotica, Acacia seyal, Balanites aegyptiaca, Cassia occidentalis, Cassia senna, Guiera senegalensis and Tamarindus indica.

CONCLUSION

This study has helped to document information that may otherwise be lost to future generations. This is the first ethnobotanical study in which statistical calculations about plants are carried out by means of the ICF and UV methods in the study area. Plants with high ICF and UV values should be subjected for further phytochemical and pharmacological investigation for scientific validation.

Agomelatine Protection in an LPS-Induced Psychosis-Relevant Behavior Model

BACKGROUND The aim of this study was to investigate the effect of agomelatine in a psychosis-relevant behavior model. MATERIAL AND METHODS We used 18 adult male Wistar rats in this study. Twelve rats given LPS for endotoxemia were randomly divided into 2 groups (n=6). Group I was treated with 1 mL/kg 0.9% NaCl i.p. and Group II was treated with 40 mg/kg agomelatine. Six normal rats served as the control group and were not given LPS for endotoxemia. Cylindrical steel cages containing vertical and horizontal metal bars with top cover were used. Rats were put in these cages for the purpose of orientation for 10 min. Apomorphine was given to rats removed from cages, and then they were immediately put back in the cages for the purpose of observing stereotyped conduct. Brain HVA levels and plasma TNF-a levels were evaluated in tissue homogenates using ELISA. The proportion of malondialdehyde (MDA) was measured in samples taken from plasma for detection of lipid peroxidation similar to thiobarbituric acid reactive substances. RESULTS LPS induced-plasma TNF-α, brain TNF-α, and plasma MDA levels were significantly lower in the LPS+agomelatine group compared to the LPS+saline group (p<0.05). HVA levels and stereotype scores were significantly lower in the LPS+agomelatine group compared to the LPS+saline group (p <0.001). CONCLUSIONS Agomelatine reduced TNF-α, HVA, MDA levels, and the stereotype score in relevant models of psychosis. Our results suggest that the anti-inflammatory effect of agomelatine involved oxidant cleansing properties and that its effects on the metabolism of dopamine can play an important role in the model of psychosis.

The Antipsychotic Effects of Omega-3 Fatty Acids in Rats

BACKGROUND

In humans, omega-3 fatty acids are necessary for cell membranes, brain function and nerve transmission continuation. When animals are exposed to a new environment-or as a result of an apomorphine application that creates an agonistic effect on D1 and D2 receptors-they display behavioral reactions like rearing and stereotypy. This study aims to reveal the possible antipsychotic and oxidative effects of omega-3 fatty acids by comparing with chlorpromazine, a conventional antipsychotic drug, through evaluating the novelty-induced rearing and apomorphine-induced stereotypic behaviors, as well as malondialdehyde and glutathione levels in rats.

METHODS

Twenty-eight, adult, male, Wistar rats were used in the study. Briefly, 4 groups of rats (n = 7) were administered docosahexaenoic acid (DHA) + eicosapentaenoic acid (EPA) (300 mg/kg; DHA: 120 mg/kg + EPA: 180 mg/kg intraperitoneally [IP]), DHA + EPA (150 mg/kg; DHA: 60 mg/kg + EPA: 90 mg/kg IP), chlorpromazine (1 mg/kg, IP) and isotonic saline (1 mL/kg, IP). One hour later, apomorphine (2 mg/kg, subcutaneously) was administered to each rat. After the apomorphine administration, rats were observed for stereotypic behavior.

RESULTS

This study shows that omega-3 fatty acids, "similar to antipsychotics," reversed the psychotic like effects, increase of oxidants and decrease of antioxidants that are composed experimentally in rats.

CONCLUSIONS

The application of omega-3 fatty acids has antipsychotic effects and causes an oxidative imbalance. This study adds new evidence to the current literature regarding the possible antipsychotic effects of omega-3 fatty acids.

Botanicals for mood disorders with a focus on epilepsy

Mood disorders are among the major health problems that exist worldwide. They are highly prevalent in the general population and cause significant disturbance of life quality and social functioning of the affected persons. The two major classes of mood disorders are bipolar disorders and depression. The latter is assumed to be the most frequent psychiatric comorbidity in epilepsy. Studies published during the second half of the 20th century recognized that certain patients with epilepsy present a depressed mood. Synthesized pharmaceuticals have been in use for decades to treat both mood disorders and epilepsy, but despite their efficiency, their use is limited by numerous side effects. On the other hand, animal models have been developed to deeply study potential botanicals which have an effect on mood disorders. Studies to investigate the potential effects of medicinal plants acting on the nervous system and used to treat seizures and anxiety are increasingly growing. However, these studies discuss the two conditions separately without association. In this review, we present animal models of depression and investigative models (methods of assessing depression) of depression and anxiety in animals. Other classical test models for prediction of clinical antidepressant activity are presented. Finally, this review also highlights antidepressant activities of herbals focusing specially on depression-like behaviors associated with epilepsy. The pharmacological properties and active principles of cited medicinal plants are emphasized. This review, therefore, provides an overview of the work done on botanicals for mood disorders, potential mechanisms of action of botanicals, and the major compounds. This article is part of a Special Issue entitled "Botanicals for Epilepsy".

Low-grade chronic inflammation induces behavioral stereotypy in rats

Schizophrenia is known to be associated with metabolic disturbances including diabetes mellitus, obesity and cardiovascular diseases. A growing body of evidence has suggested abnormal cytokine levels in schizophrenia. In the present study, we explored the effects of low-grade chronic inflammation on behavioral stereotypy in a rat model of non-alcoholic fatty liver disease (NAFLD). In order to induce NAFLD, rats were fed with either water enriched with 30 % fructose or plain tap water for 8 weeks. Following feeding period, behavioral stereotypy was evaluated with apomorphine-induced stereotypy test. Also, levels of tumor necrosis factor alpha (TNF-α), interleukin 2 (IL-2) and nuclear factor kappa B (NF-κB) in the liver and brain tissues were assessed biochemically. Brain homovanilic acid (HVA) was measured to evaluate the dopamine turnover. NAFLD rats showed significantly higher stereotypy score compared to controls (p = 0.016). TNF-α, IL-2, and NF-κB levels were significantly increased in NAFLD rats compared to control group. Brain HVA levels were elevated in NAFLD rats as well (p = 0.008). Moreover, NAFLD group prompted a considerable increase in brain IL-2 immunoexpression (p = 0.005). In conclusion, the present study demonstrates that low-grade chronic inflammation such as NAFLD may enhance apomorphine-induced stereotypic behavior via increasing dopaminergic activity in rats.

Does the description of a root system matter for sustainable use and conservation? A case study in Burkina Faso

Sarcocephalus latifolius (Sm.) E. A. Bruce is one of the most useful medicinal plants in many African countries. The root being the part generally used for this purpose. In the context of land degradation and overexploitation of biological resources in many parts of Burkina Faso, a good description of the root system is necessary to better plan for sustainable use and conservation. We aim to answer the following: i) What is the root system architecture of S. latifolius in the Sudanian zone of Burkina Faso? ii) What amount of root biomass is produced by the species? iii) Can we use a semi-destructive method to establish a model for root biomass prediction?

Forty plants were randomly selected and their dendrometric parameters were measured. For each sampled tree, the quarter of the roots were harvested and weighed. Results show the species has a superficial lateral root system. The roots grow towards other species, but do not form anatomical links with roots of other species. An allometric equation for root biomass prediction was developed through a multiple linear model. As a practical use of the present study, we propose, that people using this plant to treat illness should search for roots at approximately 10m between the trunk of mature individuals of S. latifolius and another species, instead of using roots near the trunk. Thus, only the ends of roots would be cut. Using this method could limit tree mortalities due to root harvesting and contribute to the preservation of this important species.

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.

Antipsychotic-like effect of trimetazidine in a rodent model

Trimetazidine (TMZ) has been used as an anti-ischemic agent for angina pectoris, chorioretinal disturbances, and vertigo. Also, it can induce extrapyramidal type adverse reaction such as parkinsonism, gait disorder, and tremor via blockade of D2 receptors. In the present study, we evaluated the effect of TMZ on novelty-induced rearing behavior and apomorphine-induced stereotypy behavior in male rats. Four groups of rat (n = 7) were administrated with TMZ (10 and 20 mg/kg, i.p.), chlorpromazine (1 mg/kg, i.p.), or isotonic saline. One hour later, apomorphine (2 mg/kg, s.c.) was administrated to each rat. Our results showed that both doses of TMZ significantly decreased the rearing behavior in rats, whereas the decrease with chlorpromazine was higher. TMZ also decreased the stereotypy scores in a dose-dependent manner. We concluded that TMZ has beneficial effects on rearing behavior and stereotypy, which are accepted to be indicators of antipsychotic effect. Taken together, with its antioxidative and cytoprotective properties, TMZ is worthy of being investigated for its anti-psychotic effects as a primary or an adjunctive drug.

Anti-nociceptive effect of vitexin mediated by the opioid system in mice

In the present study, we determined the potential anti-nociceptive activity of vitexin, a C-glycosylated flavone, by conducting some acute nociceptive tests in mice. Centrally mediated anti-nociceptive effect was evaluated by hot-plate and tail-clip tests, whereas peripherally mediated anti-nociception was assessed by acetic acid-induced writhing tests. Rota-rod test was performed to evaluate the probable effect of vitexin on the motor coordination of mice. Vitexin administered orally at doses of 10, 20, and 30 mg/kg significantly increased the reaction times of animals in the hot-plate and tail-clip tests and reduced the number of acetic acid-induced writhes and stretches in writhing tests, which clearly indicated the presence of the anti-nociceptive effect. This effect disappeared by pretreatment with naloxone (a non-selective opioid receptor antagonist, 5.48 mg/kg, i.p.), which indicated the involvement of opioid mechanisms in anti-nociception. We evaluated the contribution of mu, delta, and kappa subtypes of opioid receptors to the anti-nociceptive activity by using naloxonazine (7 mg/kg, s.c.), naltrindole (0.99 mg/kg, i.p.), and nor-binaltorphimine (1.03 mg/kg, i.p.), respectively. Pretreatment using these antagonists reversed the anti-nociceptive effect of vitexin in all the nociceptive tests, which indicated that mu, delta, and kappa opioid receptors contributed to the anti-nociceptive effect of this flavonoid. Falling latencies of mice in the Rota-rod test did not change upon the administration of vitexin, which indicated that vitexin showed specific anti-nociceptive effect. To the best of our knowledge, this is the first study on centrally and peripherally mediated anti-nociceptive effect of vitexin via opioid-related mechanisms.

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.

Sub-Saharan Rubiaceae: a review of their traditional uses, phytochemistry and biological activities

Rubiaceae family is a large family of 630 genera and about 13000 species found worldwide, especially in tropical and warm regions. These plants are not only ornamental but they are also used in African folk medicine to treat several diseases. Based on online published data and library bibliographic research, we herein reported accumulated information related to their traditional usages in sub-Saharan traditional medicine, their chemical composition and the screened pharmacological activities. Indeed, more than 60 species are used for more than 70 medicinal indications including malaria, hepatitis, eczema, oedema, cough, hypertension, diabetes and sexual weakness. Through biological screening following leads supplied with traditional healers, many of these plants exhibited antimalarial, antimicrobial, antihypertension, antidiabetic, antioxidant and anti-inflammatory activities. Bioactive compounds including indole alkaloids, terpenoids and anthraquinones have been isolated from these bioguided fractionation studies. It is evidence that great attention has been paid to species such as Nauclea latifolia, Morinda lucida, Mitragyna inermis and Crossopteryx febrifuga; however, several compounds should be waiting to be discovered since none of these plants has been systematically investigated for its biochemical composition. According the current global health context with the recrudescence of HIV, much effort should be oriented towards this virus when screening Rubiaceae.

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

CONTEXT

 Nauclea latifolia Smith (Rubiaceae) is a small tree found in tropical areas in Africa. It is used in traditional medicine to treat malaria, epilepsy, anxiety, pain, fever, etc.

OBJECTIVE

 The aim of this study was to investigate the effects of Nauclea latifolia roots decoction on the peripheral and central nervous systems and its possible mechanisms of action.

MATERIALS AND METHODS

 The analgesic investigation was carried out against acetic acid-induced writhing, formalin-induced pain, hot-plate and tail immersion tests. The antipyretic activity was studied in Brewer's yeast-induced pyrexia in mice. Rota-rod test and bicuculline-induced hyperactivity were used for the assessment of locomotor activity.

RESULTS

 Nauclea latifolia induced hypothermia and had antipyretic effects in mice. The plant decoction produced significant antinociceptive activity in all analgesia animal models used. The antinociceptive effect exhibited by the decoction in the formalin test was reversed by the systemic administration of naloxone, N(ω)-L-nitro-arginine methyl ester or glibenclamide. In contrast, theophylline did not reverse this effect. Nauclea latifolia (antinociceptive doses) did not exhibit a significant effect on motor coordination of the mice in Rota-rod performance. Nauclea latifolia protected mice against bicuculline-induced behavioral excitation.

DISCUSSION AND CONCLUSION

 Overall, these results demonstrate that the central and peripheral effects of Nauclea latifolia root decoction might partially or wholly be due to the stimulation of peripheric opioid receptors through the action of the nitric oxide/cyclic monophosphate guanosin/triphosphate adenosine (NO/cGMP/ATP)-sensitive- K(+) channel pathway and/or facilitation of the GABAergic transmission.

Effects of hawthorn seed and pulp extracts on the central nervous system

CONTEXT

Investigating potential central nervous system (CNS) activities of Crataegus monogyna Jacq. (Rosaceae), hawthorn, fruit extracts.

OBJECTIVE

Evaluating CNS effects and analgesic activities of hawthorn fruit extracts based on the traditional uses of the plant for neurosedative and pain killer actions.

MATERIALS AND METHODS

Effects of hawthorn pulp (HPE) and seed extracts (HSE) at the dose range of 1-1000 mg/kg were examined on anxiety level, spontaneous locomotor activity, motor coordination, and nociceptive perception of mice. Morphine was used as a reference drug.

RESULTS

HPE (100-1000 mg/kg) and HSE (10-1000 mg/kg) significantly decreased not only the exploratory behaviors in hole-board experiments, but also the spontaneous locomotor activities in activity cage tests. The same doses of extracts were found to be ineffective in Rota-Rod tests of mice. In tail-clip, hot-plate, and acetic acid-induced writhing tests, quite potent and dose-dependent analgesic activities were seen at 100-1000 mg/kg doses of HPE and 10-1000 mg/kg doses of HSE. Analgesic effects observed in all analgesia tests were antagonized by naloxone.

DISCUSSION

Significant and dose-dependent decreases in spontaneous locomotor activities and exploratory behaviors of animals suggested CNS depressant activities of both extracts. Complete naloxone antagonism in all applied analgesia tests indicated opioid-related analgesic activities of both extracts.

CONCLUSION

These findings seem to support the traditional use of this plant to treat stress, nervousness, sleep disorders, and pain control.

Pharmacological evidence favouring the use of Nauclea latifolia in malaria ethnopharmacy: effects against nociception, inflammation, and pyrexia in rats and mice

AIM OF THE STUDY

Nauclea latifolia Smith is used traditionally in the treatment of uncomplicated malaria and painful conditions among its several other applications. The objective of this study is to investigate the pharmacological activities of the plant relevant to the symptomatic treatment of malaria fever and other painful conditions as an initial step towards developing an effective therapy for the symptomatic management of malaria fever and relief of other painful conditions.

MATERIALS AND METHODS

Various concentrations of the aqueous extract of the root bark of this plant were evaluated for its anti-nociceptive, anti-inflammatory and anti-pyretic activities in mice and rats. Investigation of the anti-nociceptive activities was performed using the acetic acid-induced abdominal constriction and hot-plate tests in mice and formalin-induced pain test in rats, as models of nociception. The extract was also investigated for its effect against inflammation induced by egg-albumin and pyrexia induced by yeast in rats.

RESULTS

Our data showed that the aqueous extract of Nauclea latifolia root bark (50-200mg/kg p.o.) significantly (P<0.05) attenuated writhing episodes induced by acetic acid and increased the threshold for pain perception in the hot-plate test in mice, dose-dependently. The product also remarkably decreased both the acute and delayed phases of formalin-induced pain in rats and also caused a significant reduction in both yeast-induced pyrexia and egg-albumin-induced oedema in rats. These effects were produced in a dose-dependent manner.

CONCLUSION

The results suggest the presence of biologically active principles in the extract with anti-nociceptive, anti-inflammatory and anti-pyretic activities that justifies its use in malaria ethnopharmacy and subsequent development for clinical application.

Anticonvulsant, anxiolytic, and sedative properties of the roots of Nauclea latifolia Smith in mice

Root bark of Nauclea latifolia Smith (Rubiaceae) was evaluated for its anticonvulsant, anxiolytic, and sedative activity in mice. Animal models (maximal electroshock-, pentylenetetrazol-, and strychnine-induced convulsions; N-methyl-D-aspartate-induced turning behavior; elevated plus maze; stress-induced hyperthermia; open field; and diazepam-induced sleep) were used. The decoction from the bark of the roots of N. latifolia strongly increased the total sleep time induced by diazepam. It also protected mice against maximal electroshock-, pentylenetetrazol-, and strychnine-induced seizures. In addition, turning behavior induced by N-methyl-D-aspartate was inhibited. N. latifolia antagonized, in a dose-dependent manner, stress-induced hyperthermia and reduced body temperature. In the elevated plus maze, N. latifolia increased the number of entries into, percentage of entries into, and percentage of time in open arms, and reduced rearing, head dipping, and percentage of time in closed arms. In the open field test, N. latifolia increased crossing and reduced rearing and defecation. It could be concluded that the decoction of N. latifolia, used in traditional medicine in Cameroon in the treatment of fever, malaria, insomnia, anxiety and epilepsy seemed to possess, sedative, anticonvulsant, anxiolytic and antipyretic properties in mice.