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 LD₅₀.

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.     

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.     

Undifferentiated intratubular germ cell tumor of the testis: light and electron microscopic study of a unique case.

A 34-year-old white man was found to have a nodule on the surface of right testis which turned out to be metastatic embryonal carcinoma within the tunica albuginea. Examination of the orchiectomy specimen revealed extensive undifferentiated intratubular germ cell tumor (carcinoma in situ) with foci of intratubular embryonal carcinoma and seminoma. Ultrastructure of the cells comprising the carcinoma in situ was similar to that of undifferentiated germ cells. The development of intratubular embryonal carcinoma and seminoma in a testis with extensive carcinoma in situ lends further support to the concept that carcinoma in situ or the testis represents an undifferentiated germ cell tumor from which other types of germ cell tumors of the testis may evolve.     

Emergence of Schistosoma mansoni in the Niger River valley, Niger

Urinary and intestinal schistosomiasis are both endemic in Niger with a dominance of Schistosoma haematobium. This study pointed out the appearance of the infection to S. mansoni in the Niger River valley, where it was until then unknown in Niger. In one year the prevalence increased from 5.9 to 19.5%.     

Early intervention for the ocular and neurodevelopmental sequelae of Fetal Valproate Syndrome

The established teratogenicity of antiepileptic drugs raises important issues in women of child-bearing age. While the association between neural tube defects and antiepileptic drugs is well recognised, other congenital malformations are known to occur. We report two siblings with characteristic craniofacial features of Fetal Valproate Syndrome who also had associated ocular and neurodevelopmental problems which would benefit from early recognition and intervention.     

Heterogeneity of Schistosoma haematobium transmission in irrigated fields

Heterogeneity of Schistosoma haematobium transmission in irrigated fields. Although irrigated areas exist since a long time in the Niger Valley the distribution of the urinary schistosomiasis does not appear homogeneous, testifying to the existence of limiting or favourable factors. The identification of these factors could lead to a better definition of the distribution of the schistosomiasis risks and to optimise control programmes. The population of five villages about 1,900 inhabitants living in the same irrigated area (Sébéri) was examined at the end of 1999 before treatment and surveyed two and ten months after treatment by praziquantel in order to investigate re-infections. In parallel, the transmission sites were subject to a semi-monthly malacological follow-up from 1998 to 2001 and the water contacts were quantified in the sites of the main village during 2000. Before treatment, schistosomiasis risks appeared related to the proximity between habitat and lateral canals: the infections concerning youngers were all the more intense that the dwellings were close to the canal. The parasitological indices were the highest in the village lacking of other water sources. The morbidity indices followed a similar distribution with maximum values in the children of the 3 villages located to less than 1 km from the canal; however, morbidity was mainly observed in the adult population, in particular male, of the 2 villages which were the most distant from the canal. After treatment, the incidence of the re-infection between 2 and 10 months was comparable in the 3 villages close to the canal (28%) but was significantly weaker in the 2 villages far from the transmission sites (5%). In the villages bordering the canal, the incidence in the children was all the more high since the habitat was close to the canal. Between 1999 and 2000, the collected number of Bulinus truncatus decreased from 1.4 to 0.6 individuals per survey; moreover, no mollusc harbouring parasites was found, representing the decrease of the parasite burden. The abnormal weakness of re-infection, regarding this type of focus, could be explained by the repeated stop of water supply inducing a complete drying out of the canal for 2 months during the year preceding the study. These repeated drying out also resulted in a reduction of the exposure. Whereas the average frequentation of the sites of the canal remained rather comparable between January (cold dry season) and May (dry hot season), it decreased dramatically in September (rainy season but canals were not irrigated this year) from 99 to 11 daily contacts. The use of the lateral canal when filled represented 80% of the contacts. In the event of drying out, 80% of the contacts were transferred in the ponds but not in the river (5% of the contacts whatever the season). These results confirmed (1) that the presence of canals reduced the use of natural sites and (2) that the drying out of the canals induced a total reduction of the contacts.     

Efficacity of praziquantel in school-aged children in a hyperendemic zone for Schistoma haematobium (Niger, 1999)

Urinary schistosomiasis is endemic in the Niger river valley. The aim of the present study was to assess the efficacy and side effects of a single oral dose of praziquantel at 40 mg/kg in the treatment of schistosomiasis. The investigation took place between April 5, 1999 and May 25, 1999. A total of 318 primary school children, aged from 6 to 16 years, of a Schistosoma haematobium endemic area were included in the survey. They underwent a macroscopic and parasitological examinations of the urine before treatment and two and six weeks after treatment. Treatment with praziquantel was given at 40 mg/kg of body weight in a single dose. Side effects due to praziquantel were assessed within the first 4 hours, and 24 hours after. Side effects were frequent (53.7%), especially occurring in the first four hours. Their expression was not associated with the sex of the child nor the intensity of the infestation. We noted that elder children expressed more complaints. The most frequent symptoms were abdominal pains, headaches and pruritus. All these signs were without gravity and resolved within the first twenty-four hours. Before treatment, the prevalence of infestation was 98%. Six weeks after treatment, 32% of children remained positive despite a marked reduction of egg excretion. In this survey, the side effects of the treatment were very frequent but without gravity. Using praziquantel, 68% of the subjects were cured completely. Urinary schistosomiasis control programs can continue to use it for mass treatment without risk.     

Continued ultrasonic follow-up of children infected with Schistosoma haematobium after treatment with praziquantel

During a Schistosoma haematobium morbidity control program in Niger, we conducted a survey to describe rhe resolution of lesions after treatment with praziquantel. to determine reinfection rates and to define retreatment schedules. 114 schoolchildren (7-15 years old) living in an hyperendemic village underwent 10 successive examinations over 34 months following an initial evaluation and the administration of 40 mg/kg of praziquantel. All children, whether apparently infected with S. haematobium or not, were treated. Egg output, microhaematuria, visual aspect of urine and abnormalities of the urinary tract by ultrasound were assessed. The initial prevalence tif infection was 74.5%. Reinfection began 5 months after treatment and the final prevalence was 47.1%. Bladder abnormalities decreased rapidly, but incompletely, probably due to reinfestation: initial prevalence: 89.5%). Their prevalence increased 8 months after treatment to 72.4% at month 34. Dilatations of the upper urinary tract regressed more slowly but constantly until the end of the study (initial prevalence: 43%; 4.6% at month 34), Three years after treatment, despite reinfection, the general morbidity level (prevalence and severity of lesions) was lower than at baseline in our cohort, which would suggest the advantage of a long interval between mass treatments in the epidemiological context of our survey.