Modulation of intracellular expression of IFNγ and IL-2 in culture of splenic T lymphocytes by some flavonoid glycosides of Alchornea floribunda.

Context Alchornea floribunda Müll. Arg. (Euphorbiaceae) leaves are widely used in ethnomedicine for the management of rheumatism, arthritis and toothache. Objective In this study, flavonoid glycosides isolated from Alchornea floribunda were screened for their effect on the intracellular expression of interferon-gamma (IFNγ) and interleukin-2 (IL-2) type-1 cytokines. Materials and methods Chromatographic purification of the ethyl acetate fraction of the methanol leaf extract led to the isolation of seven flavonoid glycosides (1-7). Their structures were elucidated by 1D and 2D nuclear magnetic resonance and mass spectrometry. Splenocytes were treated with graded concentrations of the compounds (6.25-25 µg/mL) and incubated for 24 h. Thereafter, their effect on the expression of IFNγ and IL-2 by CD4(+ )and CD8(+ )T-lymphocytes was evaluated using intracellular cytokine staining and FACS analysis. Results Compounds 1-7 (6.25-25 µg/mL) caused the up-regulation of activated CD8(+ )(57.85-72.45% versus 57.85% for untreated control) and, to a lesser extent, activated CD4(+ )(3.21-7.21% versus 2.75% for the untreated control) T-lymphocytes that were both largely interferon-gamma-releasing in treated mouse T lymphocytes relative to untreated control. FACS data analysis showed that stimulation with all the compounds increased the proportion of CD8(+)/IFNγ(+ )and CD4(+)/IFNγ(+ )T lymphocytes up to two-fold when compared with the cells in untreated control wells. Intracellular IL-2 secretion by treated T cells was not detected. Conclusion This recorded T-lymphocyte-specific immune-modulatory property may contribute to explain in part the dynamics associated with the ethnomedicine of Alchornea floribunda, and may find relevance as a necessary cellular immune response precursor to infection-associated disease management.

Efficacy of Plectranthus glandulosus (Lamiaceae) and Callistemon rigidus (Myrtaceae) Leaf Extract Fractions to Callosobruchus maculatus (Coleoptera: Bruchidae).

As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, methanol crude extracts of Plectranthus glandulosus and Callistemon rigidus leaves were sequentially fractionated in hexane, chloroform, ethyl acetate, and methanol to establish the most active fraction(s) against Callosobruchus maculatus in cowpea. Cowpea seeds (25 g) were treated with 0.5, 1, 2, and 4 g/kg of extract to evaluate the contact toxicity and F1 progeny production of the beetles in the laboratory. Mortality was recorded 1, 3, and 7 d postexposure. P. glandulosus hexane fraction was more toxic than the other fractions recording 100% mortality at 4 g/kg, within 7 d with LC50 of 0.39 g/kg. Hexane fraction of C. rigidus showed superior toxicity, causing 100% mortality at 4 g/kg within only 1 d of exposure with LC50 of 1.02 g/kg. All the fractions greatly reduced progeny emergence, with C. rigidus hexane fraction being the best progeny inhibitor. Fractions of P. glandulosus and C. rigidus leaves had sufficient efficacy to be a component of storage pest management package for C. maculatus.

Creams formulated with Ocimum gratissimum L. and Lantana camara L. crude extracts and fractions as mosquito repellents against Aedes aegypti L. (Diptera: Culicidae).

Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined actions against female Aedes aegypti. Evaluation was carried out in the net cages (30 by 30 by 30 cm) containing 60 blood-starved female mosquitoes each and were assayed in the laboratory condition following World Health Organization 2009 protocol. All formulations (single and mixture) were applied at 2, 4, 6, and 8 mg/cm(2) in the exposed area of human hands. Only acetone + white soft paraffin served as negative control and odomos (12% DEET) as positive control. All the formulations presented good protection against mosquito bites without any allergic reaction by the human volunteers. The repellent activity was dependent on the strength of the extracts and fractions. Among the tested formulations, the maximum protection time was observed in MCE (120 min) and EAF (150 min) of O. gratissimum; MCE:MCE (150 min) and HF:HF (120 min) mixtures of both plants. In addition, MCE:MCE and HF:HF mixtures from both plants showed possible synergistic effect. From the results, the combination of O. gratissimum and L. camara to formulate natural mosquito repellent using small amount of extracts can be encouraging to be an alternative to conventional DEET.

Azadirachta indica extract-artesunic acid combination produces an increased cure rate of Plasmodium berghei-infected mice.

CONTEXT: Available artemisinin-combination therapies (ACTs) are expensive. Various traditional herbal remedies for malaria involve plants, proven scientifically to have antiplasmodial effects, e.g., Azadirachta indica A. Juss. (Meliaceae). OBJECTIVE: Combination of an artemisinin-based compound and a medicinal herb extract will provide an indigenous alternative/herb-based ACT. MATERIALS AND METHODS: The in vivo schizontocidal activity of the crude aqueous extract of 100, 500, and 1000 mg/kg of A. indica fresh leaves (NCE) and 6, 15, and 20 mg/kg of artesunic acid were determined, alone and in combination, while keeping the dose of artesunic acid constant at 15 mg/kg, using the Peter's 4-day suppressive test and Swiss albino mice. The ED50 was calculated from the dose-response relationships. Percentage survival and cure were also determined. RESULTS: The average yield of two extractions of NCE was 8.33 ± 1.67%. Combination of 1000 mg/kg of NCE and 15 mg/kg of artesunic acid, produced a significant reduction of parasitemia (96.87%), compared to 20 mg/kg of artesunic acid alone (68.14%). The combination had an ED50 of 0.58 mg/kg while that of artesunic acid alone was 8.814 mg/kg. The combinations of NCE with artesunic acid produced a cure, although the artesunic acid did not produce a cure in 30 d. DISCUSSION: NCE increased the activity of artesunic acid in terms of reduction in parasitemia, and increased survival time and cure rate. CONCLUSION: The combination of an artemisinin and aqueous extract of neem leaf is possible, providing a potentiated reduction of parasitemia, and increased cure rate.

In vitro antiplasmodial and anticancer analyses of endophytic fungal extracts isolated from selected Nigerian medicinal plants.

Ethnomedicinal plants are thought to have better prospects of harboring endophytes that produce natural products with pharmacological activities. This study aimed to investigate the antiplasmodial and anticancer properties of secondary metabolites of endophytic fungi from three medicinal plants. The endophytic fungi included Lasiodiplodia theobromae isolated from Cola acuminata, Curvularia lunata Bv4 isolated from Bambusa vulgaris, and Curvularia lunata Eg7 isolated from Elaeis guineensis. The identification of the fungi was based on the internal transcribed spacer (ITS-rDNA) sequence. The fungi were subjected to solid-state fermentation and the secondary metabolites were extracted with ethyl acetate. In vitro antiplasmodial screening of extracts was performed using the SYBR green I-based fluorescence assay on the chloroquine-resistant Plasmodium falciparum strain DD2. The cytotoxicity of the extracts on human red blood cells and Jurkat (leukemia) cells was assessed using the tetrazolium-based colorimetric MTT assay. Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the constituents of the fungal extracts. The extract of L. theobromae showed the best antiplasmodial activity against chloroquine-resistant P. falciparum (IC50 = 5.4 µg/mL) and was not harmful to erythrocytes (CC50 > 100 µg/mL). All three fungal extracts showed a weak cytotoxic effect against Jukart cell lines (CC50 > 100 µg/mL). GC-MS analysis of the three endophytic fungal extracts revealed the presence of forty major bioactive compounds, including: oxalic acid, isobutyl nonyl ester, 2,4-di-tert-butylphenol, and hexadecanoic acid, among others. The endophytic fungi from the medicinal plants in this study were promising sources of bioactive compounds that could be further evaluated as novel drugs for the treatment of malaria caused by P. falciparum-resistant strains.

Antibiotypes and high frequency of toxin genes in methicillin-resistant Staphylococcus pseudintermedius from nares of dogs and dog guardians in Nigeria.

To determine the antibiotypes and frequency of toxin genes in methicillin-resistant Staphylococcus pseudintermedius (MRSP), 281 nasal swab samples were collected from dogs and dog guardians in Abakaliki, Southeastern Nigeria. Antimicrobial susceptibility testing was determined by disc diffusion technique while detection of toxin genes was carried out by PCR. Exactly 41 (28.7 %) and 6 (4.3 %) MRSP were obtained from dogs and dog guardians respectively. Isolates exhibited resistance (100-16.7 %) to amoxicillin-clavulanic acid, cephalosporins, fluoroquinolones, and carbapenems. Seccanine, lukD, siet, and exi toxin genes were harboured by 42 (89.4 %), 47 (100 %), 37 (78.7 %), and 2 (4.3 %) MRSP isolates respectively. This study has shown that dogs and dog guardians in Abakaliki, Southeastern Nigeria are colonized by multiple drug-resistant MRSP which harbour toxin genes. This represents a significant public health problem in veterinary and human medicine.

A novel sesquiterpene acid and an alkaloid from leaves of the Eastern Nigeria mistletoe, Loranthus micranthus with potent immunostimulatory activity on C57BL6 mice splenocytes and CD69 molecule.

CONTEXT: The Eastern Nigeria mistletoe, Loranthus micranthus Linn. (Loranthaceae), is used in the treatment of several diseases including immune-modifying diseases and thus there is a need to identify the immunoactive constituents. OBJECTIVE: This research isolated and characterized the immunoactive constituents in the Eastern Nigeria mistletoe. MATERIALS AND METHODS: Bioassay-guided fractionation was employed in the isolation and purification of the constituents. The characterized compounds were screened for immunostimulatory activities on isolated C57BL/6 mice splenocytes and early activation marker, CD69 at concentrations of 10, 25, and 100 µg/mL using flow cytometry techniques and compared to lipopolysaccharide (LPS; 10 µg/mL) and concanavalin A (ConA; 2 µg/mL) as standards. RESULTS: Two compounds, a novel sesquiterpene, 2, 3-dimethoxy-benzo [a, b] cyclopentenyl-3',3',5'-trimethyl pyran-4-carboxylic acid, and a known alkaloid, lupinine were isolated and characterized. The compounds (25 µg/mL) showed statistically significantly (p < 0.05) stimulatory activity on the splenocytes with values of 56.34 ± 0.26% and 69.84 ± 0.19%, respectively, compared to 7.58 ± 0.42% recorded for the unstimulated control. Similarly, the CD69 expression assay showed immunostimulation with statistically significant values (p < 0.05) of 2.31 ± 0.07% and 2.71 ± 0.03%, respectively, compared to 1.69 ± 0.05% recorded for the nonstimulated control. DISCUSSION: These data suggest that the isolated compounds possess immunomodifying abilities. In addition, the activation of the CD69 molecule is possibly one of its mechanisms of action. CONCLUSION: These compounds may be responsible in part, for the immunostimulatory activities already established for the Eastern Nigeria mistletoes.

COVID-19 vaccine hesitancy among staff and students in a Nigerian tertiary educational institution.

BACKGROUND: COVID-19 was first reported on 31 December 2019 and has so far claimed over 2,000 lives in Nigeria. Through global and national efforts, about 4 million doses of the AstraZeneca vaccine was distributed and used in Nigeria from March 2021. Vaccine hesitancy could pose a serious problem for COVID-19 prevention and control. OBJECTIVES: To estimate the proportion of the Nnamdi Azikiwe University community that is willing to be vaccinated against COVID-19; level of hesitancy and its associated factors. METHODS: A cross-sectional survey was conducted using online Google form distributed to staff and students of the university via different WhatsApp groups. The outcome measures were the proportion of persons willing to be vaccinated, vaccine hesitancy rates and reasons for this hesitancy. Data were analyzed using SPSS version 23 and Minitab version 19. Bivariate analysis was performed by the chi-square test, Odds Ratios (ORs) and statistical significance was accepted when p-value is < 0.05. RESULTS: Only 349 of the survey responses were analyzed in the survey. Results show that 34.70 ± 5.00% of the university community were willing to receive the COVID-19 vaccine when it is offered to them. The COVID-19 hesitancy rate among staff and students was 65.04 ± 5.00%. It was discovered that marital status (OR = 2.06), age (OR = 0.802) and christian denominational affiliation (OR = 0.366) influenced respondents' perception of COVID-19 vaccination. Gender, occupation, previous vaccination experience, awareness of COVID-19 and previous symptoms of COVID-19 did not significantly (p = 0.05) influence respondents' willingness to be vaccinated. CONCLUSION: COVID-19 vaccine hesitancy is high among staff and students in a Nigerian university and is significantly influenced by marital status, respondents' age and christian denominational affiliation.

Biosurfactant Production Using Mutant Strains of Pseudomonas aeruginosa and Bacillus subtilis from Agro-industrial Wastes.

Purpose: Biosurfactants are applied in drug formulations to improve drug solubility and in some cases, treat diseases. This study is focused on generating, extracting, purifying and then characterizing biosurfactants from bacterial isolates of palm oil wastes and abattoir soil origins. Methods: Eight bacteria were isolated from the soil and sludge samples, out of which four (50%) were found to produce biosurfactants. Bacillus subtilis (37.5%) and Pseudomonas aeruginosa (50%) were isolated and identified from these samples using mineral salt medium, nutrient agar and Cetrimide agar. Mutant isolates of B. subtilis BS3 and P. aeruginosa PS2 were used to produce biosurfactants using mineral salt medium as enrichment medium and extraction was done using membrane filter. Results: The mutant strains B. subtilis BS3 and P. aeruginosa PS2 generated biosurfactants that displayed significant solubility and dissolution properties by enhancing the percentage solubility of piroxicam to 62.86 and 54.29% respectively, and achieved 51.71 and 48.71% dissolution of the drug in 0.1N HCl. Conclusion: From the results obtained, the produced biosurfactants could serve as a better alternative to conventional surfactants. Notably, the study indicated that the biosurfactant produced by mutant strain of B. subtilis produced more potent activities (surface tension reduction ability, high emulsification) than those of P. aeruginosa.

The Activating Receptors of Natural Killer Cells and Their Inter-Switching Potentials.

The global incidence of cancer is on the increase and researchers are prospecting for specific and non-selective therapies derived from the immune system. The killer activating receptors of NK cells are known to be involved in immunosurveillance against tumor and virally-infected cells. These receptors belong to two main categories, namely the immunoglobulin like and C-lectin like families. Though they have different signal pathways, all the killer activating receptors have similar effector functions which include direct cytotoxicity and the release of inflammatory cytokines such as IFN-gamma and TNF-alpha. To transduce signals that exceed the activation threshold for cytotoxicity, most of these receptors require synergistic effort. This review profiles 21 receptors: 13 immunoglobulin-like, 5 lectin-like, and 3 others. It critically explores their structural uniqueness, role in disease, respective transduction signal pathways and their status as current and prospective targets for cancer immunotherapy. While the native ligands of most of these receptors are known, much work is required to prospect for specific antibodies, peptides and multi-target small molecules with high binding affinities.

Efficacy and safety of Syferol-IHP for the treatment of peptic ulcer disease: a pilot, double-blind randomized trial.

BACKGROUND: To our knowledge, there is no prior randomized study on the utility of Syferol-IHP (blend of virgin coconut oil and Ocimum sanctum oil) when coadministered with a triple therapy schedule. AIM: This study determined the efficacy and safety of Syferol-IHP as adjunct to conventional triple therapy for the treatment of peptic ulcer disease (PUD). METHODS: A pilot double-blind randomized trial was conducted in patients with confirmed diagnosis (endoscopy-guided biopsy) of PUD. Eligible patients were randomized to Pylorest (a three-in-one tablet containing rabeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg) and Syferol-IHP for 2 weeks, followed by rabeprazole and Syferol-IHP for 2 weeks or Pylorest and placebo for 2 weeks, followed by rabeprazole and placebo for 2 weeks. Repeat endoscopy-guided biopsy and histology were done 4 weeks posttherapy. Primary outcome measures were the healing of ulcer and eradication of Helicobacter pylori. Secondary outcome measures were the disappearance of epigastric pain, gastritis, and duodenitis. Analysis was by intention-to-treat. RESULTS: Of the 63 patients enrolled, 60 patients had complete evaluation, with 37 patients receiving Pylorest and Syferol-IHP and 23 patients receiving Pylorest and Placebo. Healing of the PUD in favor of Pylorest and Syferol-IHP was significantly higher for gastric ulcer (RR=0.000, 95% CI=undefined, P=0.048) but not for duodenal ulcer (RR=0.400, 95% CI=0.07-2.37, P=0.241). H. pylori eradication was 100% with Syferol-IHP vs 50% with placebo (P=0.066). Epigastric pain (reduction to 16.2% vs 43.5%; P=0.021), gastritis (reduction to 13.5% vs 39.1%; P = 0.024), and duodenitis (reduction to 0% vs 8.7%; P=0.327) were observed in the Syferol-IHP and Pylorest vs placebo and Pylorest groups, respectively. Adverse events (RR=0.971, 95% CI=0.46-2.04, P=0.937) and laboratory parameters were not significantly different pre- and posttherapies (P>0.05, for both groups). CONCLUSION: Although both treatment arms were equally safe, co-administration of Syferol-IHP and triple therapy is more efficacious than triple therapy alone for treating PUD. Pan African Clinical trial registry identifier number is PACTR201606001665364.

Antioxidant, Anti-inflammatory, Analgesic Properties, and Phytochemical Characterization of Stem Bark Extract and Fractions of Anthocleista nobilis.

BACKGROUND: Anthocleista nobilis (Loganiaceae) is used by Mbano people of Imo State, Nigeria, for the treatment of various ailments. OBJECTIVE: The aim of this study is to evaluate the antioxidant, anti-inflammatory, and analgesic properties of the methanol extract, fractions, and subfractions of A. nobilis. MATERIALS AND METHODS: The powdered stem bark was extracted with methanol and sequentially fractionated into n-hexane, ethyl acetate, and butanol fractions. The constituents of the fractions were analyzed using high-pressure liquid chromatography (HPLC), and the components were identified by dereplication. Antioxidant potential of the extracts and fractions was investigated using 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging method. Anti-inflammatory and analgesic activities of the extract and fractions were also investigated using xylene-induced inflammation and acetic acid-induced writhing models, respectively. RESULTS: A total of five compounds isovitexin (Rt = 18.77 min), isovitexin-2''-O-xyl (Rt = 19.68 min), p-Hydroxybenzoic acid (Rt = 11.88 min), Sarasinoside L (Rt = 19.64 min), isovitexin (Rt = 18.77), and apigenin monoglycoside (Rt = 19.64 min) were identified by HPLC analysis and dereplication. The ethyl acetate fraction and subfraction elicited the best anti-inflammatory activity. The ethyl acetate subfraction also inhibited acetic acid-induced pain by 79% and 85.0% at the doses of 100 mg/kg and 200 mg/kg, respectively, which was better than 71.1% and 81.3% observed for diclofenac at similar doses. CONCLUSION: A. nobilis could be a potential source of anti-inflammatory and analgesic lead compounds. SUMMARY: The extract, fractions and subfractions of Anthocleista nobilis were screened or antioxidant, anti-inflammatory and Analgesic properties in vitro and in mice models. Some of the components were identified by dereplication after HPLC analysis. The results demonstrated potent anti-inflammatory and analgesic property of the extracts and fractions. The dereplication analysis also identified vitexin and related compounds. Abbreviation used: HPLC: High performance Liquid Chromatography; VLC: Vacuum Liquid Chromatography; DPPH: 2,2-Diphenyl-1-pycrylhydrazine; SPSS: Statistical Package for the Social Sciences; ROS: Reactive Oxygen Species.

An evaluation of the cold chain technology in South-East, Nigeria using Immunogenicity study on the measles vaccines.

INTRODUCTION: Vaccines are biological products and their efficacy is affected by storage conditions. They are vital in promoting public health. Failures in immunization programmes often times are blamed on disruption in vaccine cold-chain. This study assessed the immunogenicity/potency of the measles vaccines utilized in childhood immunization in South-East, Nigeria and indirectly assessed the effectiveness of the cold-chain technology in the region. METHODS: This was an experimental study carried out between December 2011 and June 2013. Antibody induction method was used to evaluate the immunogenicity/potency of the measles vaccines sourced from the central cold chain facilities in South-east, Nigeria and indirectly, the effectiveness of the cold chain technology in the zone in maintaining vaccine potency. The neutralizing antibodies in a control group (administered with measles vaccines stored at 37°C for 12 months) and in immunized group were determined after 30 days of immunization using ELISA. RESULTS: The mean storage temperature of the vaccines at the states vaccines central cold chain facilities was -2.4°C and before storage at study site, it was 5.8°C but at the study site it was -4.54°C. Mean ±Standard Error in the Mean (SEM) IgG titers for the measles vaccines sourced from "Open Market", Ebonyi, Enugu, Imo, Anambra and Abia States were 0.793±0.051, 1.621±0.015, 1.621±0.015, 1.715±0.081, 1.793±0.051 and 1.683±0.078 respectively while the mean ±Standard Error in the Mean (SEM) IgM titres were 0.857±0.037, 1.400±0.030, 1.391±0.032, 1.339±0.037, 1.405±0.066 and 1.279±0.025 respectively. One way analysis of variance shows that there is statistical difference in the IgG and IgM antibodies titers produced by the control compared to the vaccines (P value < 0.0001). Also, Bartlett's test for equal variances showed that there was statistical difference (P value < 0.0001 for IgG and = 0.036 for IgM). The antibodies elicited by the vaccines from the states were enough to confer protection but the vaccine samples from "Open Market" (control) could not evoke enough antibodies. CONCLUSION: The cold-chain technology in the region was judged to be optimal as at the time of vaccine sampling since all the measles vaccines had good immunogenicity profile. However, efforts are still needed to maintain these facilities in good condition in order to ensure effective immunization program in the region.

Toxicity of Boswellia dalzielii (Burseraceae) Leaf Fractions Against Immature Stages of Anopheles gambiae (Giles) and Culex quinquefasciatus (Say) (Diptera: Culicidae).

Mosquitoes are vectors of several human pathogens, and great attention has recently been placed on insecticides from plant-derived products, in search for mosquito control agents. This study, thus, investigated the potency of Boswellia dalzielii methanol leaf extract and its four fractions as mosquito ovicide, larvicide, and pupicide against Anopheles gambiae and Culex quinquefasciatus. The plant products were tested at the following concentrations: 125, 250, 500, 1000, and 2000 ppm on eggs and 312.5, 625, 1250, and 2500 ppm on the larvae and pupae of the mosquitoes. For results, hatchability of A. gambiae eggs was reduced to 5% with n-hexane fraction at 2000 ppm. Among the plant products tested, n-hexane fraction was most toxic against A. gambiae (LC50 = 385.9 ppm) and C. quinquefasciatus (LC50 = 3394.9 ppm). The n-hexane fraction of B. dalzielii might be used as a mosquitocidal agent in the breeding sites of A. gambiae and C. quinquefasciatus.

Laboratory Evaluations of the Fractions Efficacy of Annona senegalensis (Annonaceae) Leaf Extract on Immature Stage Development of Malarial and Filarial Mosquito Vectors.

BACKGROUND: Within the framework to control mosquitoes, ovicidal, larvicidal and pupicidal activity of Annona senegalensis leaf extract and its 4 fractions against Anopheles gambiae and Culex quinquefasciatus were evaluated in the laboratory conditions. METHODS: Ovicidal test was performed by submitting at least 100 eggs of mosquitoes to 125, 250, 500, 1000 and 2000 ppm concentrations, while larvicidal and pupicidal effects were assessed by submitting 25 larvae or pupae to the concentrations of 2500, 1250, 625 and 312.5 ppm of plant extract or fractions of A. senegalensis. RESULTS: The eggs of An. gambiae were most affected by N-hexane (0.00% hatchability) and chloroform (03.67% hatchability) fractions compared to Cx. quinquefasciatus where at least 25 % hatchability were recorded at 2000 ppm. For larvicidal test, N-hexane (LC50= 298.8 ppm) and chloroform (LC50= 418.3 ppm) fractions were more effective than other fractions on An. gambiae larvae while, a moderate effectiveness was also observed with N-hexane (LC50= 2087.6 ppm), chloroform (LC50= 9010.1 ppm) fractions on Cx. quinquefasciatus larvae. The highest mortality percent of the pupae were also recorded with N-hexane and chloroform fractions on An. gambiae at 2500 ppm. As for Cx. quinquefasciatus only 50 % and 36 % mortality were recorded with N-hexane and chloroform fractions respectively. CONCLUSION: The extract of A. senegalensis was toxic on immature stage of mosquito species tested. By splitting methanolic crude extract, only N-hexane and chloroform fractions were revealed to possess a mosquitocidal effects and could be considered and utilized for future immature mosquito vectors control.

New neolignan glycoside and an unusual benzoyl malic acid derivative from Maytenus senegalensis leaves.

Further investigation of the methanol leaf extract of Maytenus senegalensis led to the isolation of six compounds, including mayselignoside (1) and an unusual benzoyl malic acid derivative, benzoyl R-(+)-malic acid (2). Two known lignan derivatives (+)-lyoniresinol (3) and (-)-isolariciresinol (4), a known neolignan derivative dihydrodehydrodiconiferyl alcohol (5) and the triterpenoid, ß-amyrin (6) were also isolated. The structures of these compounds were elucidated by a combination of 1D and 2D NMR and mass spectroscopy. All compounds were tested for cytotoxicity against mouse lymphoma cell line (L5178Y) and for antimicrobial activity against strains of bacteria and fungi. None of the compounds showed promising cytotoxic and/or antimicrobial activities.

Hemozoin inhibition and control of clinical malaria.

Malaria has a negative impact on health and social and economic life of residents of endemic countries. The ultimate goals of designing new treatment for malaria are to prevent clinical infection, reduce morbidity, and decrease mortality. There are great advances in the understanding of the parasite-host interaction through studies by various scientists. In some of these studies, attempts were made to evaluate the roles of malaria pigment or toxins in the pathogenesis of malaria. Hemozoin is a key metabolite associated with severe malaria anemia (SMA), immunosuppression, and cytokine dysfunction. Targeting of this pigment may be necessary in the design of new therapeutic products against malaria. In this review, the roles of hemozoin in the morbidity and mortality of malaria are highlighted as an essential target in the quest for effective control of clinical malaria.

Phospholipon 90H (P90H)-based PEGylated microscopic lipospheres delivery system for gentamicin: an antibiotic evaluation.

OBJECTIVE: To formulate gentamicin liposphere by solvent-melting method using lipids and polyethylene glycol 4 000 (PEG-4 000) for oral administration. METHODS: Gentamicin lipospheres were prepared by melt-emulsification using 30% w/w Phospholipon® 90H in Beeswax as the lipid matrix containing PEG-4 000. These lipospheres were characterized by evaluating on encapsulation efficiency, loading capacity, change in pH and the release profile. Antimicrobial activities were evaluated against Escherichia coli, Pseudomonas aeruginosa, Salmonella paratyphii and Staphylococcus aureus using the agar diffusion method. RESULTS: Photomicrographs revealed spherical particles within a micrometer range with minimal growth after 1 month. The release of gentamicin in vitro varied widely with the PEG-4 000 contents. Moreover, significant (P>0.05) amount of gentamicin was released in vivo from the formulation. The encapsulation and loading capacity were all high, indicating the ability of the lipids to take up the drug. The antimicrobial activities were very high especially against Pseudomonas compare to other test organisms. This strongly suggested that the formulation retain its bioactive characteristics. CONCLUSIONS: This study strongly suggest that the issue of gentamicin stability and poor absorption in oral formulation could be adequately addressed by tactical engineering of lipid drug delivery systems such as lipospheres.

Three hydroxylated lupeol-based triterpenoid esters isolated from the Eastern Nigeria mistletoe parasitic on Kola acuminata.

Column fractionation and purification of an n-hexane fraction led to the isolation of three lupeol-based triterpenoid esters from the leaves of the Eastern Nigeria mistletoe, Loranthus micranthus Linn parasitic on a local kola nut tree, Kola acuminata. These three compounds were adequately characterised using a combination of UV/visible, IR, NMR (¹³C-NMR and ¹H-NMR), DEPT, MS and two-dimensional correlation (H-H COSY, Hetero-nuclear Single Quantum Correlation (HSQC), HMBC, NOE and NOESY) studies as 7ß,15α-dihydroxyl-lup-20(29)-ene-3ß-esters of palmitic (I), stearic (II) and eicosanoic acids (III). The characterisation of other isolated compounds is ongoing. Remarkably, this is the first report of the existence of fatty acid esters of an unusual 7ß,15α-dihydroxylated lupeol in the Eastern Nigeria mistletoe. These isolated compounds might contribute in part to the numerous established bio-activities of the Eastern Nigeria mistletoes.