17 research outputs found
Insecticidal effect of anisaldehyde against Acanthoscelides obtectus and Callosobruchus maculatus (Coleoptera: Bruchidae)
In the present study, anisaldehyde, a compound found in the essential oil of Clausena anisum-olens, was tested for its insecticidal activities against Acanthoscelides obtectus and Callosobruchus maculatus. The amounts of anisaldehyde applied were 0, 0.5, 1, 2 and 4 μL diluted in 1mL of acetone and applied to 40 g of either beans or cowpeas corresponding to the doses of 0, 0.008, 0.016, 0.033 and 0.066 μL/g of seed. Additionally, adsorbent clay was used as a carrier of this product in order to increase the persistence of its insecticidal activity over time. This clay was mixed with the aforementioned volumes of anisaldehyde to form a powder formulation. Furthermore, to assess the insecticidal effect over time, the F1 progeny production was also evaluated. These two products caused significant mortality in the two tested insects. Nevertheless, C. maculatus was more susceptible than A. obtectus at tested doses. The progeny production decreased with the increasing doses of anisaldehyde and ACP with 0 % at the highest dose (0.066 μL/g). According to the LD50, LD95 and their confidence intervals, the toxicity of ACP was significantly different (P < 0.05) to anisaldehyde at the tested doses towards A. obtectus adults. However, there was no significant difference observed between the effects of these two products towards C. maculatus. These preliminary results suggest that anisaldehyde and ACP could be used in stored-product protection, but this needs further research. Research is also needed to determine its toxicity on rats in order to assess its potential hazards for workers and consumers.Keywords: Anisaldehyde, Clay, Contact toxicity, Bruchid
Anticancer and antibacterial secondary metabolites from the endophytic fungus Penicillium sp. CAM64 against multi-drug resistant Gram-negative bacteria.
Background: The emergence of multiple-drug resistance bacteria has
become a major threat and thus calls for an urgent need to search for
new effective and safe anti-bacterial agents. Objectives: This study
aims to evaluate the anticancer and antibacterial activities of
secondary metabolites from Penicillium sp. , an endophytic fungus
associated with leaves of Garcinia nobilis . Methods: The culture
filtrate from the fermentation of Penicillium sp. was extracted and
analyzed by liquid chromatography\u2013 mass spectrometry, and the
major metabolites were isolated and identified by spectroscopic
analyses and by comparison with published data. The antibacterial
activity of the compounds was assessed by broth microdilution method
while the anticancer activity was determined by the
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.
Results: The fractionation of the crude extract afforded penialidin A-C
(1-3), citromycetin (4), p-hydroxyphenylglyoxalaldoxime (5) and
brefelfin A (6). All of the compounds tested here showed antibacterial
activity (MIC = 0.50 \u2013 128 \u3bcg/mL) against Gramnegative
multi-drug resistance bacteria, Vibrio cholerae (causative agent of
dreadful disease cholera) and Shigella flexneri (causative agent of
shigellosis), as well as the significant anticancer activity (LC50 =
0.88 \u2013 9.21 \u3bcg/mL) against HeLa cells. Conclusion: The
results obtained indicate that compounds 1-6 showed good antibacterial
and anticancer activities with no toxicity to human red blood cells and
normal Vero cells
Antimicrobial activity of extracts and a germacranolidetype sesquiterpene lactone from Tithonia diversifolia leaf extract
The in vitro antimicrobial activity of the hexane, ethyl acetate and methanol extracts of the leaf of Tithonia diversifolia, and one sesquiterpene lactone 1 isolated from the ethyl acetate extract wasstudied. Of the fourteen strains of bacteria used, the ethyl acetate extract was the most active, showing inhibitory activity against five Gram +ve and two Gram –ve organisms. This was followed by the hexane extract and then methanol. The ethyl acetate fractions (TDE 2 – TDE 5, TDE 7, TDE 8 and TDE 10) showed varying degrees of inhibitory activity. The sesquiterpene lactone 1 showed activity against all the tested microorganisms, except Staphylococcus aureus and Bacillus cereus (MICs = 15.6 – 62.5mg/ml for most stains). All the extracts, fractions and compound 1 showed activity against the fungusCandida albicans. The results of the present study indicate that the non-polar leaf extract of T.diversifolia could be useful in the treatment of some disease conditions and the sesquiterpene lactone 1 could be a good candidate as a phytotherapeutic agent against some bacterial infection
ANTIMOTILITY AND ANTISECRETORY RELATED ANTIDIARRHOEAL ACTIVITY OF THE ABELMOSCHUS MOSCHATUS MEDIK IN EXPERIMENTAL ANIMAL MODELS
Objective: This study was intended to evaluate the anti-diarrhoeal potential of Abelmoschus moschatus Medik (A. moschatus Medik) seeds and the possible mechanism therein involved by using different experimental models in albino Wistar rats.Methods: The hydroalcoholic seed extract of A. moschatus Medik. (HEAM) was orally administered at the doses of 150, 300 and 500 mg/kg respectively to the different groups in order to assess the effect of extract in castor oil induced diarrhea model in rats. In order to comprehend the mechanism involved in its anti-diarrhoeal potential, the extract was further investigated for its effect on gastrointestinal motility using charcoal meal test and antisecretory action by castor oil induced intestinal enter pooling where, atropine sulphate (5 mg/kg) and loperamide (2 mg/kg) were used as reference standards respectively.Results: The HEAM exhibited significant (p<0.05, p<0.001) and dose-dependent anti-diarrhoeal effect by decreasing the mean number of fecal droppings produced upon castor oil administration as compared to the normal control. The effect of the extract at 500 mg/kg was near to that of loperamide (2 mg/kg). The extract (300 mg/kg) showed antimotility action by significantly (p<0.05, p<0.001) attenuating the charcoal meal transit in the intestine as compared to negative control animals. Further, the extract showed significant (p<0.05, p<0.001) inhibition in the accumulation of intestinal fluid due to castor oil.Conclusion: The HEAM exhibited significant anti-diarrhoeal action that could be presumably related to its observed antimotility and antisecretory activities. This study justifies the usage of A. moschatus Medik. as an anti-diarrhoeal agent in traditional practices of medicine
Synergistic effects of Persicaria odorata (Daun Kesom) leaf extracts with standard antibiotics on pathogenic bacteria
Antibacterial activity of different types of P. odorata leaf extracts was evaluated in combination with standard antibiotics. Persicaria. odorata leaves were extracted with n-hexane (n-hex), dichloromethane (DCM) and methanol (MeOH). Each extract was applied on vancomycin (30μg), erythromycin (15μg) and gentamicin (10μg) discs, respectively. Disk diffusion method was used to evaluate the synergistic activity of each combination on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli. Minimum inhibitory concentration (MIC) and gas chromatography mass spectrometry (GCMS) analysis was performed on the active extract. Synergistic effects seen were mainly from the n-hex+antibiotics combinations, mainly on the Gram-positive bacteria (7 additive, 5 antagonistic), with MIC range from 50 μg/ml to 100 μg/ml, as well as Gram-negative bacteria (2 additive, 2 indifferent, 5 antagonistic). In particular, synergism showed by the combination of n-hex+van were all additive against the susceptible bacteria. DCM extract combination showed synergistic effects on three Gram-positive species (S. aureus, S. epidermidis, S. pyogenes). Meanwhile, MeOH+antibiotics combination showed significant additive synergistic effects (p<0.05) on S. aureus and S. epidermidis. The major compounds of leaves extract were decanal and β-citral. n-Hex extract superiorly inhibited Gram-positive bacteria growth as compared to DCM and MeOH extracts. The additive synergistic property of the n-hex P. odorata extract could be further studied for possible use as an antibacterial agent
Anti-vibrio potentials of acetone and aqueous leaf extracts of Ocimum gratissimum (Linn)
Purpose: To evaluate the anti-vibrio potentials of acetone and aqueous leaf extracts of Ocimum gratissimum and determine its relevance in the treatment of vibrios infection.Methods: The agar-well diffusion method was used for screening the extracts for their anti-vibrio activity. Broth micro-dilution assay was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts. Time-kill assay was used to assess bactericidal and/or bacteriostatic activity.Results: The acetone extract showed activity against 47.5 % (19/40) of the test bacteria, while the aqueous extract had activity against 30 % (12/40). MIC and MBC values range for the acetone extract were 0.625 – 5.0 mg/mL and 2.5 – 10 mg/mL respectively. The range of MIC exhibited by the antibiotic (gentamicin) against the vibrios is 0.002 mg/mL and >0.256 mg/mL. Significant reduction in the bacterial density was at 2 × MIC after a 4 h interaction period, while bacterial density after 6 and 8 h interactions with extract was highly bactericidal. Growth inhibition and efficacy of the crude acetone extract were observed to be both concentration- and time-dependent.Conclusion: The bacteriostatic and bactericidal activities observed for Ocimum gratissimum leaf suggest that the plant is a potential source of bioactive components that may be effective in the treatment of vibrios infections.Keywords: Ocimum gratissimum, Vibrios infection, Antibiotics, Multi-drug resistance, Minimum inhibitory concentration, Minimum bactericidal concentration, Time kill assa
Effect of Hours of Priming in Coconut Water and Seed Weight on the Juvenile Growth Phase of Soursop (Annona Muricata) in the Nursery
Priming in coconut water and seed weight are important nursery techniques for seedling emergence and vigorous juvenile growth phase in the nursery. Two hundred and ten (210) observational stands of soursop seedlings were gotten from five (5) seeds of 0.6 - 0.8 g and 0.3 - 0.5 g weights which were primed in coconut water at 0, 12, 24, 36, 48, 60 and 72 hours and replicated three times. Findings showed that heavy seed had higher percentage emergence (92.90 %) than light seed (78.60 %). Priming in coconut water at 60 hours (83.30 %) increased percentage emergence while unprimed seed had low percentage emergence (75.00 %). Juvenile growth phase showed a linear increase as hours of priming in coconut water increased, peaked at 60 hours of priming and dropped at 72 hours of priming. Dry matter content of heavy seed primed at 60 hours (4.20 g) was higher than dry matter content of light seed primed at 72 hours (1.55 g). Dry matter content correlates positively (p < 0.05) with growth parameters measured. These results showed that hours of priming in coconut water and seed weight played crucial roles in juvenile growth phase of soursop in the nursery
Launch of the Laboratory for Major Tropical Epidemics (LAGET) in Chad: Strengthening the capacity for epidemiological surveillance, monitoring and diagnosis of endemic or emerging infectious diseases in Central Africa
In an increasingly interconnected world, with the devastating effects of climate changes and humanitarian crises, pandemics and emerging infectious diseases are more likely to become our daily reality. When it comes to health care, sub-Saharan Africa faces more challenges than most other regions of the world, including lack of funds, precarity and poor infrastructures. Yet, these areas are most often on the front lines of infectious threats
Antioxidant and Antimalarial Activities of Methanol Extract of Picralima nitida Root Bark
Ethnomedically, the root, stem bark, seed or leaves of Picralima nitida are relevant in local preparations as antimalaria, antipyretic, antihypertensive and gastrointestinal agents. This study was therefore designed to determine the antimalarial and antioxidant effects of the methanol extract of the root bark of Picralima nitida using standard procedures. The antioxidant activity of the methanol root bark extract was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method and ferric reducing antioxidant power (FRAP) assay. The antimalarial activity of the methanol root bark extract was investigated using the 4-day suppressive test in mice infected with Plasmodium berghei. The extract showed a concentration-dependent antioxidant activity with 50% inhibitory concentration (IC50) for free radical scavenging activity of 10.19 µg/mL, while the FRAP value was 0.17 ± 0.00 mM FSE/g Extract. The extract demonstrated significant antimalarial activity with 68.33% and 67.27% parasitaemia suppression at doses of 400 mg/kg and 800 mg/kg, respectively. The present study has shown that the root bark extract of P. nitida has antioxidant and antimalarial activities. This study does not only validate the claimed ethnomedicinal use of the plant as antimalaria but also has shown the plant as a potential source of active antimalarial agent