Chemical composition of Hyptis suaveolens and Ocimum gratissimum hybrids from Nigeria

Four medicinal plants belonging to the family Lamiaceae were chemically screened for their chemical constituents including alkaloids, tannins, saponins, flavonoids and phenols. The medicinal plants investigated were Hyptis suaveloens and three putative hybrids of Ocimum gratissimum (Hybrid A, B and C). All the plants contains high percentage yield of crude alkaloids and flavonoids ranging from 10.44 to 14.32% and 9.28 to 12.54%, respectively. Only H. suaveloens is devoid of saponins. Tanninsand phenols were present in all plants. The nutritional values of the phytochemicals were also assessed with a view of establishing and understanding their nutritional uses. The plants contained crude protein(9.19 to 17.94%), crude fibre (4.88 to 9.04%), ash (5.68 to 6.88%), carbohydrate (66.24 to 75.87%), crude lipid (3.48 to 4.90%) and food energy (357.68 to 373.26 mg/cal). The significance of the plants in traditional medicine and the importance of the chemical constituents in the pharmaceutical industries were discusse

Evaluation of antibody response to Plasmodium falciparum in children according to exposure of Anopheles gambiae s.l or Anopheles funestus vectors

<p>Abstract</p> <p>Background</p> <p>In sub-Saharan areas, malaria transmission was mainly ensured by <it>Anopheles. gambiae </it>s.l. and <it>Anopheles. funestus </it>vectors. The immune response status to <it>Plasmodium falciparum </it>was evaluated in children living in two villages where malaria transmission was ensured by dissimilar species of <it>Anopheles </it>vectors (<it>An. funestus vs An. gambiae </it>s.l.).</p> <p>Methods</p> <p>A multi-disciplinary study was performed in villages located in Northern Senegal. Two villages were selected: Mboula village where transmission is strictly ensured by <it>An. gambiae </it>s.l. and Gankette Balla village which is exposed to several <it>Anopheles </it>species but where <it>An. funestus </it>is the only infected vector found. In each village, a cohort of 150 children aged from one to nine years was followed during one year and IgG response directed to schizont extract was determined by ELISA.</p> <p>Results</p> <p>Similar results of specific IgG responses according to age and <it>P. falciparum </it>infection were observed in both villages. Specific IgG response increased progressively from one-year to 5-year old children and then stayed high in children from five to nine years old. The children with <it>P. falciparum </it>infection had higher specific antibody responses compared to negative infection children, suggesting a strong relationship between production of specific antibodies and malaria transmission, rather than protective immunity. In contrast, higher variation of antibody levels according to malaria transmission periods were found in Mboula compared to Gankette Balla. In Mboula, the peak of malaria transmission was followed by a considerable increase in antibody levels, whereas low and constant anti-malaria IgG response was observed throughout the year in Gankette Balla.</p> <p>Conclusion</p> <p>This study shows that the development of anti-malaria antibody response was profoundly different according to areas where malaria exposure is dependent with different <it>Anopheles </it>species. These results are discussed according to i) the use of immunological tool for the evaluation of malaria transmission and ii) the influence of <it>Anopheles </it>vectors species on the regulation of antibody responses to <it>P. falciparum</it>.</p

Antibody-Mediated Growth Inhibition of Plasmodium falciparum: Relationship to Age and Protection from Parasitemia in Kenyan Children and Adults

BACKGROUND: Antibodies that impair Plasmodium falciparum merozoite invasion and intraerythrocytic development are one of several mechanisms that mediate naturally acquired immunity to malaria. Attempts to correlate anti-malaria antibodies with risk of infection and morbidity have yielded inconsistent results. Growth inhibition assays (GIA) offer a convenient method to quantify functional antibody activity against blood stage malaria. METHODS: A treatment-time-to-infection study was conducted over 12-weeks in a malaria holoendemic area of Kenya. Plasma collected from healthy individuals (98 children and 99 adults) before artemether-lumefantrine treatment was tested by GIA in three separate laboratories. RESULTS: Median GIA levels varied with P. falciparum line (D10, 8.8%; 3D7, 34.9%; FVO, 51.4% inhibition). The magnitude of growth inhibition decreased with age in all P. falciparum lines tested with the highest median levels among children \u3c4 years compared to adults (e.g. 3D7, 45.4% vs. 30.0% respectively, p = 0.0003). Time-to-infection measured by weekly blood smears was significantly associated with level of GIA controlling for age. Upper quartile inhibition activity was associated with less risk of infection compared to individuals with lower levels (e.g. 3D7, hazard ratio = 1.535, 95% CI = 1.012-2.329; p = 0.0438). Various GIA methodologies had little effect on measured parasite growth inhibition. CONCLUSION: Plasma antibody-mediated growth inhibition of blood stage P. falciparum decreases with age in residents of a malaria holoendemic area. Growth inhibition assay may be a useful surrogate of protection against infection when outcome is controlled for age

Variations in killer-cell immunoglobulin-like receptor and human leukocyte antigen genes and immunity to malaria

Malaria is one of the deadliest infectious diseases in the world. Immune responses to Plasmodium falciparum malaria vary among individuals and between populations. Human genetic variation in immune system genes is likely to play a role in this heterogeneity. Natural killer (NK) cells produce inflammatory cytokines in response to malaria infection, kill intraerythrocytic Plasmodium falciparum parasites by cytolysis, and participate in the initiation and development of adaptive immune responses to plasmodial infection. These functions are modulated by interactions between killer-cell immunoglobulin-like receptors (KIR) and human leukocyte antigens (HLA). Therefore, variations in KIR and HLA genes can have a direct impact on NK cell functions. Understanding the role of KIR and HLA in immunity to malaria can help to better characterize antimalarial immune responses. In this review, we summarize the different KIR and HLA so far associated with immunity to malaria.This work was supported through the DELTAS Africa Initiative (Grant no. 107743), that funded Stephen Tukwasibwe through PhD fellowship award, and Annettee Nakimuli through group leader award. The DELTAS Africa Initiative is an independent funding scheme of the African Academy of Science (AAS), Alliance for Accelerating Excellence in Science in Africa (AESA) and supported by the New Partnership for Africa’s Development Planning and Coordinating Agency (NEPAD Agency) with funding from the Wellcome Trust (Grant no. 107743) and the UK government. Francesco Colucci is funded by Wellcome Trust grant 200841/Z/16/Z. The project received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 695551) for James Traherne and John Trowsdale. Jyothi Jayaraman is a recipient of fellowship from the Centre for Trophoblast Research

Pharmaceutical and therapeutic potential of some wild Cucurbitaceae species from South East Nigeria

The phytochemical screening of some wild Cucurbitaceae species from South – East Nigeria, was investigated to determine their pharmaceutical and Therapeutic potential. The four plant species used for the study were Lagenaria vulgaris, Trichosanthes cucumerina, Momordica charantia and Luffa cylinderical. The leaves, pericarp and seeds of the plants were investigated. Alkaloids, flavonoids, phenols, saponin and tannins were found in all the plant parts analyzed and in all the plant species. Averagely, the phytochemical constituent of the plants are as follows: alkaloid (0.02- 0.07 mg ml-1), flavonoid (0.05- 0.12 mg ml-1), phenol (0.077- 0.978 mg ml-1), saponin (0.04- 0.08 mg ml-1) and tannin (0.283- 0.982 mg ml-1). The leaves of the plants have the highest amount of tannins and phenols, while the seeds contain the highest concentration of alkaloids and flavonoids. The least amount of saponin was found in the seeds of the plants. The results obtained were discussed in respect to the roles of the plants and their phytochemicals in maintenance of good health

Palynological analysis of Annona muricata, A. squomosa and A. senegalensis

Palynological analysis of Annona senegalensis Pers., Annona squamosa Linn. and Annona muricata Linn. was carried out to compare the pollen morphology of these species and to identify the differences, if any, that might warrant their re-classification. Fresh flowers of these plants were collected, dried and crushed to liberate the pollen grains. The liberated pollen grains were subjected to acetolysis treatment and then examined under the microscope. Photomicrograph of the pollen was taken using trinocular microscope fitted with a digital camera. Results showed that all the plants had tetrad, acalymate pollen that were inaperturate. Pollens of A. senegalensis and A. squamosa were tetragonal with a globose shape, rugulate exine ornamentation and an intectate exine inner structure. On the contrary, pollen of A. muricata was rhomboidal with an ellipsoidal shape, reticulate exine ornamentation and a semitectate exine inner structure. A. muricata had the highest pollen size with tetrad and monad diameter of 229 μm and 111 μm, respectively while A. squamosa had the least (tetrad diameter = 99 μm; monad diameter = 50 μm). Sexine was only present in A. muricata (5.5 μm). The observed differences in the pollen morphology of these three studied species do not warrant their re-classification

Uncovering supramolecular chirality codes for the design of tunable biomaterials

Abstract In neurodegenerative diseases, polymorphism and supramolecular assembly of β-sheet amyloids are implicated in many different etiologies and may adopt either a left- or right-handed supramolecular chirality. Yet, the underlying principles of how sequence regulates supramolecular chirality remains unknown. Here, we characterize the sequence specificity of the central core of amyloid-β 42 and design derivatives which enable chirality inversion at biologically relevant temperatures. We further find that C-terminal modifications can tune the energy barrier of a left-to-right chiral inversion. Leveraging this design principle, we demonstrate how temperature-triggered chiral inversion of peptides hosting therapeutic payloads modulates the dosed release of an anticancer drug. These results suggest a generalizable approach for fine-tuning supramolecular chirality that can be applied in developing treatments to regulate amyloid morphology in neurodegeneration as well as in other disease states