Biomedical subjects

N N Ntonifor

Publications and source records attributed to N N Ntonifor.

4 recordsLinked to original sources

PubMed2006

Molluscicidal activity of some Cameroonian plants on Bulinus species.

OBJECTIVE: To evaluate some locally available plants for their molluscicidal activity on Bulinus camerunensis and B. truncatus (slender form). DESIGN: Experimental studies. SETTING: Ndongo stream near the University of Buea and the University of Buea Life Sciences Laboratory. SUBJECTS: Evaluation of molluscicidal activity on snails of Bulinus camerunensis and B. truncatus (slender form). MAIN OUTCOME MEASURES: Plant extracts with molluscicidal activity determined. Determination of LC50, LC90 and LC100 of the potent plant extracts. Application of the extracts on aquaria-reared snails. Semi-field application of extracts. RESULTS: A preliminary screening test using 10,000 ppm solution of the water extracts of thirteen plants revealed that 61.5% (8/13) of the plants investigated had molluscicidal properties, with snail mortality rates above 90%. Extracts of Nicotiana tabacum, Aframomum citratum, A. melegueta, Curcuma domestica and Solanum scabrum killed 100% of the snails after twenty four hours exposure. B. camerunensis was more susceptible to the water extracts than B. truncatus. The LC50, LC90 and LC100 of the different plant extracts against B. camerunensis were generally lower than those against B. truncatus. The concentrations that produced 50%, 90% and 100% snail mortalities were lower with the methanol extracts than with water extracts, indicating that the methanol extracts were more toxic. to the snails than the water extracts. Generally, the eggs were more susceptible to the extracts than the young and adult snails. Application of the water extracts at LC 100 on snails reared in aquaria and under semi-field conditions revealed that N. tabacum could kill up to 100% of the snails in aquaria and 61.25% under semi-field conditions. CONCLUSION: Eight plant species with molluscicidal activity were identified, among which Nicotiana tabacum, Aframomum citratum, A. melegueta, Solanum scabrum and Curcuma domestica presented the highest activity. B. camerunensis was more susceptible to all the plant extracts tested than B. truncatus, and the methanol extracts proved more toxic than the water extracts. Semi-field testing of potent extracts showed promise, with N. tabacum having the highest effects on the snails.

Animals↗

PubMed2005

Evaluating a malaria intervention strategy using knowledge, practices and coverage surveys in rural Bolifamba, southwest Cameroon.

We evaluated the impact of a malaria intervention in Bolifamba in rural Cameroon. The intervention consisted of educating the community on management of malaria and provision of a dispensary for early diagnosis and treatment. In July 2001, prior to the intervention, a questionnaire was used to obtain information on knowledge of and practices toward childhood malaria of 185 mothers of children aged 0-5 years. The same questionnaire was administered to 120 of the 185 mothers, one-year post-intervention. Clinical and laboratory investigations were carried out on children whose mothers were interviewed. A comparison of pre- and post-intervention data indicated significant changes in (i) the use of appropriate malaria treatment (from 50% to 81.7%); (ii) recognition of splenomegaly as a feature of malaria (from 18.4% to 80.8%); (iii) prevalence of splenomegaly (from 26.5% to 13.3%); (iv) prevalence of fever (from 27.8% to 13.3%); (v) parasite prevalence (from 60.5% to 44.2%) and (vi) severe malaria anaemia (from 2.6% to 0.0%). These findings revealed that proper education of villagers, particularly mothers, on malaria and the presence of health facilities, where treatment is readily available at affordable cost, close to villages, are important strategies that would reduce malaria morbidity and mortality significantly.

Adolescent↗

PubMed2005

The epidemiology of malaria in Bolifamba, a rural community on the eastern slopes of Mount Cameroon: seasonal variation in the parasitological indices of transmission.

The prevalences of malarial parasitaemia, fever, splenomegaly and anaemia and the levels of parasitaemia were investigated, through part of one wet season (in 2001) and the following dry season (in 2002), in 2157 subjects in the village of Bolifamba, in south-western Cameroon. Overall, 55.9% of the villagers checked in the wet season but only 49.5% of those examined in the dry season were found smear-positive for malaria (P<0.0001). Rainfall was found to be significantly associated with the mean level of parasitaemia (P=0.001). The prevalences of fever (40.3% v. 19.6%), splenomegaly (37.4% v. 4.0%) and marked splenomegaly (i.e. a Hackett's score of 2 or higher; 25.8% v. 2.4%) were all significantly higher in the wet season than in the dry (P<0.0001 for each). No seasonal difference was observed, however, in the prevalence of anaemia. Parasitaemia, fever, splenomegaly and anaemia were all significantly more common in the young children investigated (i.e. those aged < 5 years) than in the older subjects. When the data were subjected to a multiple logistic regression, age-group, anaemia, fever, and month of examination were all found to be significantly associated with the presence of malarial parasitaemia. The results of this large-scale study, the first of its kind in the Buea district of Cameroon, indicate the intense transmission of malarial parasites in rural Bolifamba, with young children at greatest risk. The data collected provide a useful 'base line' for an ongoing study to assess the immune status of the residents of Bolifamba.

Adolescent↗

PubMed2002

Advantages of soxflo extractions for phytochemical analysis and bioassay screening. 1. Terpenoids.

The Soxflo technique was evaluated for the rapid extraction of plant materials (<90 min) at room temperature. Qualitatively similar chromatograms were obtained by gas chromatography and thin layer chromatography (TLC) with Soxflo (SoF) and Soxhlet (SoL) extracts. Sequential solvent extractions by SoF gave slightly higher yields (132%) of five major sesquiterpenoids. TLC revealed that SoF extractions at room temperature were more selective as extracts contained compounds with a narrower range of R(f)() values. This means that the SoF technique offers the potential for one-step extractions and partial fractionation. This study also showed that there were large differences in the volatile composition of dried and fresh Piper fruits: dried fruits had predominantly sesquiterpenoids while fresh fruits had considerable quantities of both mono- and sesquiterpenoids. This is the first report of alpha-guaiene and alpha- and beta-selinene in Piper guineense fruits. It is suggested that the SoF technique can be useful for the screening of large numbers of plants for phytochemicals or for the preparation of plant extracts for subsequent bioassay studies.

Chromatography, Thin Layer↗