Larvicidal activity of essential oil from citrus sinensis and Citrus paradisi against Anopheles gambiae

Malaria is a major health challenge in the developing world causing millions of death annually. Synthetic pesticides used in the vectors control are not environmentally safe and are expensive. We screened the essential oils of Citrus sinensis and Citrus paradisi peels at concentrations ranging between 40 and 400 ppm against late 3rd instar of Anopheles gambiae larvae. The effects of ethanol and methanol on the larvicidal activity of these oils were examined. The effects of combined oils formulations on larvicidal activity were also determined. The larvicidal concentration (LC50) of the orange and grape oil was 73ppm and 76 ppm, respectively in methanol, and 121 ppm and 82 ppm in ethanol solution. The LC50 of the combined oil formulations ranged between 54 and 99ppm. The different oil combinations showed synergism except when combined at equal proportion in ethanol. Conclusively, orange and grape oils could be used as biopesticides against A. gambiae larvae.Keywords: Anopheles gambiae; Citrus paradisi; Citrus sinensis; essential oils; Mosquito larvaeBiokemistri 28(1): 16–2

Targeting IgE and Th2-Cytokines in Allergy: Brief Updates on Monoclonal Antibodies and Antibody Gene Therapy

The search for an effective treatment of allergic conditions is an ongoing global health challenge due to the high prevalence of allergies. Epinephrine and glucocorticosteroids remain the oldest and most widely used treatment regimen for allergy, and these medications are for short relief. In extreme allergy manifestations, the current treatment options aim to use monoclonal antibody (mAb) to target pathological pathways of inflammation involving mast cells, eosinophils, and basophils. These cells have the propensity to induce an allergic-inflammatory response. Studies have shown that they are responsible for several allergic diseases, such as allergic asthma, atopic dermatitis, rhinitis, and conjunctivitis. Studies evaluating monoclonal antibodies against serum IgE (Omalizumab), Th-2 cytokines, such as IL-4, IL-13 (dupilumab), and IL-5 suggest an attenuation of allergic symptoms and improvement in patients’ overall well-being. However, several factors such as cost of production (i.e., antibody purification), host immunogenicity, safety, and efficacy have hindered the availability of purified mAb in developing countries. Gene therapy is a promising tool for treating allergy, and emerging studies have suggested that antibody gene therapy may be the future for treating extreme cases of allergy manifestations. This paper describes the use of purified monoclonal antibodies for treating severe allergic responses and the associated limitations. It explores the prospects of antibody gene therapy for modulating allergy episodes

Ameliorative effect of the hydroethanolic whole plant extract of Digitaria horizontalis (Poaceae) against haloperidol-induced catalepsy in mice

Background: Digitaria horizontalis is used in Traditional African Medicine in the management of nervous disorders.Objective: This study was carried out to investigate the protective effect of hydroethanolic whole plant extract of D. horizontalis 1 against haloperidol-induced catalepsy in mice.Methods: Male albino mice (17-21 g) randomly divided into six groups (n=6); (1) normal saline, vehicle control (10 ml/kg), (2) vehicle positive control, (3) trihexylphenidyl (0.5 mg/kg, i.p.), (4-6) DH (12.5, 50 or 100 mg/kg), 1 h posttreatment haloperidol (1 mg/kg, i.p.) for 14 consecutive days. The neurobehavioral effect of the extract was evaluated using the bar, open field, elevated plus maze, forced swim and climbing tests. At the end of the study, biochemical markers of nitrosative and oxidative stress status were determined.Results: DH (12.5, 50 and 100 mg/kg) significantly ameliorated haloperidol-induced catalepsy (bar test), spontaneous motor and working memory deficits (open field and elevated plus maze tests, respectively), depressive-like behavior and motor coordination deficits (forced swim and climbing tests, respectively) compared to vehicle-treated control. Haloperidol injection increased level of lipid peroxidation and deficits in the level of antioxidant enzymes which was attenuated by pretreatment of mice with DH. To corroborate these findings, DH scavenged 1-1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide and ferric ion induced free radicals in vitro.Conclusion: Findings from this study suggests that the hydroethanolic whole plant extract of D. horizontalis possesses antioxidant, neuroprotective, nootropic andantidepressant-like properties. Thus, could be a potential phytotherapeutic in the management of drug-induced Parkinsonism.Keywords: Digitaria horizontalis; neuroprotective; haloperidol; nootropic; catalepsy; antioxidant

Pigment Produced by Glycine-Stimulated <i>Macrophomina Phaseolina</i> Is a (−)-Botryodiplodin Reaction Product and the Basis for an In-Culture Assay for (−)-Botryodiplodin Production

An isolate of Macrophomina phaseolina from muskmelons (Cucumis melo) was reported by Dunlap and Bruton to produce red pigment(s) in melons and in culture in the presence of added glycine, alanine, leucine, or asparagine in the medium, but not with some other amino acids and nitrogen-containing compounds. We explored the generality and mechanism of this pigment production response using pathogenic M. phaseolina isolates from soybean plants expressing symptoms of charcoal rot disease. A survey of 42 M. phaseolina isolates growing on Czapek-Dox agar medium supplemented with glycine confirmed pigment production by 71% of isolates at the optimal glycine concentration (10 g/L). Studies in this laboratory have demonstrated that some pathogenic isolates of M. phaseolina produce the mycotoxin (−)-botryodiplodin, which has been reported to react with amino acids, proteins, and other amines to produce red pigments. Time course studies showed a significant positive correlation between pigment and (−)-botryodiplodin production by selected M. phaseolina isolates with maximum production at seven to eight days. Pigments produced in agar culture medium supplemented with glycine, beta-alanine, or other amines exhibited similar UV-vis adsorption spectra as did pigments produced by (±)-botryodiplodin reacting in the same agar medium. In a separate study of 39 M. phaseolina isolates, red pigment production (OD520) on 10 g/L glycine-supplemented Czapek-Dox agar medium correlated significantly with (−)-botryodiplodin production (LC/MS analysis of culture filtrates) in parallel cultures on un-supplemented medium. These results support pigment production on glycine-supplemented agar medium as a simple and inexpensive in-culture method for detecting (−)-botryodiplodin production by M. phaseolina isolates