Antimycobacterial activity of some medicinal plants in Niger state, Nigeria

Ten Nigerian medicinal plants Abrus precatorius, Annona senegalensis, Anogeissus leiocarpus, Crateva adansonii, Detarium microcarpum, Faba spp, Neocarya macrophylla, Ocimum gratissimum, Securidacalongpenduculata and Terminalia avicennioides used by traditional medicine practitioners for the management of infectious and chronic diseases such as tuberculosis and whooping cough were investigated for in vitro antimycobacterial activity against attenuated strains of Mycobacterium bovis (BCG). Hexane and methanol extracts of the plant materials were obtained by maceration. The antimycobacterial activity was determined by the broth microdilution method. The hexane extracts of Anogeissus leiocarpus and Terminalia avicennioides showed stronginhibitory activity at 312μg/ml. Eight of the ten plant extracts showed moderate inhibitory activity in either hexane or methanol extract at 1250μg/ml. While the hexane and methanol extracts of Detarium microcarpum and Neocarya macrophylla did not exhibit any significant activity. These observed activities could be associated with secondarymetabolites in these plants. This study demonstrates the efficacy of Nigerian medicinal plants as potential agents in the management of the tuberculosis disease.Key words: Antimycobacterial activity, Nigeria, Medicinal plants, Secondary metabolites, Tuberculosi

The Prevalence of Malaria Parasitic Infections in Cord Blood: Association with Some Socio Demographic Profile

This study aimed at investigating the relationship between some selected socio demographic profile and malaria parasitic infections in cord blood. It involved 100 cord blood samples of newly delivered babies at the Irrua Specialist Teaching Hospital, Irrua, Edo State. Samples were subjected to microscopic examinations following standard protocols and the prevalence of malaria parasitic infections in cord blood were identified using thick and thin blood films. Plasmodium species and packed cell volume were identified and determined using rapid antigen techniques and microhaematocrit respectively. Results showed that malaria parasite was present in 9.0% of samples and was higher in babies with weights ≤1.0kg (66.70%) and PCV of 25.50% (15.40%). As regards species distribution, Plasmodium falciparum had the highest prevalence (6%). Based on the methods used, microscopic method had higher prevalence (9%) over rapid detection technique (6%). On the methods used, malaria parasitic infections was also higher among the age 36-40 years (12.5%), primigravidae (15.6%), rural dwellers (16.1%), unskilled labour (22.2%), educational status ≤SSCE (12.5%) and mothers that do not use prophylaxis (45.5%). Overall, the prevalence of malaria parasites in cord blood is low in the studied area, yet the associated consequence of mother-to-child transmission can not be ignored.Keywords: Babies, Cord blood, Demographic profile, Malaria parasites, Relationship

The contribution of nitrogen by promiscuous soybeans to maize based cropping the moist savanna of Nigeria

Agronomic results indicate that maize grain yields generally are higher when the crop is planted following soybean than in continuous maize cultivation in the moist savanna agroecological zones of West Africa. Many factors have been hypothesized to explain this phenomenon, including enhanced N availability and the so-called `rotational effect'. There is, however, hardly any quantitative information on the residual N benefits of promiscuous soybeans to subsequent cereal crops grown in rotation with soybean. Three IITA promiscuous soybean breeding lines and two Brazilian soybean lines were grown in 1994 and 1995 at Mokwa in the southern Guinea savanna, Nigeria, to quantify the nitrogen contribution by soybeans to a succeeding crop of maize grown in rotation with soybean for two consecutive years, 1996 and 1997 using two methods of introducing 15N into soil (fresh 15N labelling and its residual 15N) and three maize cultivars (including one cultivar with high N use efficiency) used as reference plants. The nodulating soybeans fixed between 44 and 103 kg N ha−1 of their total N and had an estimated net N balance input from fixation following grain harvest ranging from −8 to 43 kg N ha−1. Results in 1996 and in 1997 showed that maize growing after soybean had significantly higher grain yield (1.2 – 2.3-fold increase compared to maize control) except for maize cultivar Oba super 2 (8644-27) (a N-efficient hybrid). The 15N isotope dilution method was able to estimate N contribution by promiscuous soybeans to maize only in the first succeeding maize crop grown in 1996 but not in the second maize crop in 1997. The first crop of maize grown after soybean accumulated an average between 10 and 22 kg N ha−1 from soybean residue, representing 17–33% of the soybean total N ha−1. The percentage 15N derived from residue recovery in maize grown after maize was influenced by the maize cultivars. Maize crop grown after the N-efficient hybrid cultivar Oba Super 2 (844-27) had similar 15N values similar to maize grown after soybeans, confirming the ability of this cultivar to use N efficiently in low N soil due to an efficient N translocation ability. The maize crop in 1997 grown after maize had lower 15N enrichment than that grown in soybean plots, suggesting that soybean residues contributed a little to soil available N and to crop N uptake by the second maize crop. The differential mineralization and immobilization turnover of maize and soybean residues in these soils may be important and N contribution estimates in longer term rotation involving legumes and cereals may be difficult to quantify using the 15N labelling approaches. Therefore alternative methods are required to measure N release from organic residues in these cropping systems

ANTIMYCOBACTERIAL ACTIVITY OF SOME MEDICINAL PLANTS IN NIGER STATE, NIGERIA

Ten Nigerian medicinal plants Abrus precatorius, Annona senegalensis, Anogeissus leiocarpus, Crateva adansonii, Detarium microcarpum, Faba spp, Neocarya macrophylla, Ocimum gratissimum, Securidaca longpenduculata and Terminalia avicennioides used by traditional medicine practitioners for the management of infectious and chronic diseases such as tuberculosis and whooping cough were investigated for in vitro antimycobacterial activity against attenuated strains of Mycobacterium bovis (BCG). Hexane and methanol extracts of the plant materials were obtained by maceration. The antimycobacterial activity was determined by the broth microdilution method. The hexane extracts of Anogeissus leiocarpus and Terminalia avicennioides showed strong inhibitory activity at 312µg/ml. Eight of the ten plant extracts showed moderate inhibitory activity in either hexane or methanol extract at 1250µg/ml. While the hexane and methanol extracts of Detarium microcarpum and Neocarya macrophylla did not exhibit any significant activity. These observed activities could be associated with secondary metabolites in these plants. This study demonstrates the efficacy of Nigerian medicinal plants as potential agents in the management of the tuberculosis disease

Unexpected High Losses of Anopheles gambiae Larvae Due to Rainfall

Background - Immature stages of the malaria mosquito Anopheles gambiae experience high mortality, but its cause is poorly understood. Here we study the impact of rainfall, one of the abiotic factors to which the immatures are frequently exposed, on their mortality. Methodology/Principal Findings - We show that rainfall significantly affected larval mosquitoes by flushing them out of their aquatic habitat and killing them. Outdoor experiments under natural conditions in Kenya revealed that the additional nightly loss of larvae caused by rainfall was on average 17.5% for the youngest (L1) larvae and 4.8% for the oldest (L4) larvae; an additional 10.5% (increase from 0.9 to 11.4%) of the L1 larvae and 3.3% (from 0.1 to 3.4%) of the L4 larvae were flushed away and larval mortality increased by 6.9% (from 4.6 to 11.5%) and 1.5% (from 4.1 to 5.6%) for L1 and L4 larvae, respectively, compared to nights without rain. On rainy nights, 1.3% and 0.7% of L1 and L4 larvae, respectively, were lost due to ejection from the breeding site. Conclusions/Significance - This study demonstrates that immature populations of malaria mosquitoes suffer high losses during rainfall events. As these populations are likely to experience several rain showers during their lifespan, rainfall will have a profound effect on the productivity of mosquito breeding sites and, as a result, on the transmission of malaria. These findings are discussed in the light of malaria risk and changing rainfall patterns in response to climate chang

Development of environmental tools for anopheline larval control

<p>Abstract</p> <p>Background</p> <p>Malaria mosquitoes spend a considerable part of their life in the aquatic stage, rendering them vulnerable to interventions directed to aquatic habitats. Recent successes of mosquito larval control have been reported using environmental and biological tools. Here, we report the effects of shading by plants and biological control agents on the development and survival of anopheline and culicine mosquito larvae in man-made natural habitats in western Kenya. Trials consisted of environmental manipulation using locally available plants, the introduction of predatory fish and/or the use of <it>Bacillus thuringiensis </it>var. <it>israelensis </it>(<it>Bti</it>) in various combinations.</p> <p>Results</p> <p>Man-made habitats provided with shade from different crop species produced significantly fewer larvae than those without shade especially for the malaria vector <it>Anopheles gambiae</it>. Larval control of the African malaria mosquito <it>An. gambiae </it>and other mosquito species was effective in habitats where both predatory fish and <it>Bti </it>were applied, than where the two biological control agents were administered independently.</p> <p>Conclusion</p> <p>We conclude that integration of environmental management techniques using shade-providing plants and predatory fish and/or <it>Bti </it>are effective and sustainable tools for the control of malaria and other mosquito-borne disease vectors.</p

Global Distribution of Outbreaks of Water-Associated Infectious Diseases

Water is essential for maintaining life on Earth but can also serve as a media for many pathogenic organisms, causing a high disease burden globally. However, how the global distribution of water-associated infectious pathogens/diseases looks like and how such distribution is related to possible social and environmental factors remain largely unknown. In this study, we compiled a database on distribution, biology, and epidemiology of water-associated infectious diseases and collected data on population density, annual accumulated temperature, surface water areas, average annual precipitation, and per capita GDP at the global scale. From the database we extracted reported outbreak events from 1991 to 2008 and developed models to explore the association between the distribution of these outbreaks and social and environmental factors. A total of1,428 outbreaks had been reported and this number only reflected ‘the tip of the iceberg’ of the much bigger problem. We found that the outbreaks of water-associated infectious diseases are significantly correlated with social and environmental factors and that all regions are affected disproportionately by different categories of diseases. Relative risk maps are generated to show ‘hotspots’ of risks for different diseases. Despite certain limitations, the findings may be instrumental for future studies and prioritizing health resources

Productivity of Malaria Vectors from Different Habitat Types in the Western Kenya Highlands

BACKGROUND: Mosquito Larval Source Management (LSM) could be a valuable additional tool for integrated malaria vector control especially in areas with focal transmission like the highlands of western Kenya if it were not for the need to target all potential habitats at frequent intervals. The ability to determine the productivity of malaria vectors from identified habitats might be used to target LSM only at productive ones. METHODS: Each aquatic habitat within three highland sites in western Kenya was classified as natural swamp, cultivated swamp, river fringe, puddle, open drain or burrow pit. Three habitats of each type were selected in each site in order to study the weekly productivity of adult malaria vectors from February to May 2009 using a sweep-net and their habitat characteristics recorded. RESULTS: All surveyed habitat types produced adult malaria vectors. Mean adult productivity of Anopheles gambiae sensu lato in puddles (1.8/m(2)) was 11-900 times higher than in the other habitat types. However, puddles were the most unstable habitats having water at 43% of all sampling occasions and accounted for 5% of all habitats mapped in the study areas whereas open drains accounted for 72%. Densities of anopheline late instars larvae significantly increased with the presence of a biofilm but decreased with increasing surface area or when water was flowing. Taking stability and frequency of the habitat into account, puddles were still the most productive habitat types for malaria vectors but closely followed by open drains. CONCLUSION: Even though productivity of An. gambiae s.l. was greatest in small and unstable habitats, estimation of their overall productivity in an area needs to consider the more stable habitats over time and their surface extension. Therefore, targeting only the highly productive habitats is unlikely to provide sufficient reduction in malaria vector densities