Antibacterial and Antioxidant Properties of the Methanolic Extract of the Stem Bark of Pteleopsis hylodendron (Combretaceae)

Pteleopsis hylodendron (Combretaceae) is used in Cameroon and West Africa folk medicine for the treatment of various microbial infections (measles, chickenpox, and sexually transmitted diseases). The antibacterial properties of the methanolic extract and fractions from stem bark of Pteleopsis hylodendron were tested against three Gram-positive bacteria and eight Gram-negative bacteria using Agar-well diffusion and Broth microdilution methods. Antioxidant activities of the crude extract and fractions were investigated by DPPH radical scavenging activity and β-carotene-linoleic acid assays. The methanolic extract and some fractions exhibited antibacterial activities that varied between the bacterial species (ID = 0.00–25.00 mm; MIC = 781–12500 μg/mL and 0.24–1000 μg/mL). The activity of the crude extract is, however, very weak compared to the reference antibiotics (MIC = 0.125–128 μg/mL). Two fractions (FE and FF) showed significant activity (MIC = 0.97 μg/mL) while S. aureus ATCC 25922 was almost resistant to all the tested fractions. In addition, the crude extract and some fractions showed good antioxidant potential with inhibition values ranging from 17.53 to 98.79%. These results provide promising baseline information for the potential use of this plant as well as some of the fractions in the treatment of infectious diseases and oxidative stress

Evaluation of Hybridization in Two African Catfishes (Siluriformes, Clariidae): Exotic (Clarias gariepinus Burchell, 1822) and Native (Clarias jaensis Boulenger, 1909) Species under Controlled Hatchery Conditions in Cameroon

The study was conducted to evaluate reciprocal hybridizations in the African catfishes Clarias gariepinus and Clarias jaensis using artificial reproduction under controlled hatchery conditions. The results revealed that the highest fertilization (82.77%) and hatching (67.77%) rates were achieved in the hybrid cross female C. jaensis × male C. gariepinus (Fcj × Mcg). Deformed larvae rates ranged from 9.01 to 16.33%; the hybrid Fcj × Mcg recorded the lowest rate. Survival rates in the larval stage were higher than 80% whatever crossing considered. However, it was higher in the hybrid Fcj × Mcg unlike its homologous female C. gariepinus × male C. jaensis (Fcg × Mcj) which recorded the lowest value (81.70%). In the fry stages D32, survival rates were low than 65%. They were higher and comparable in parental cross Fcg × Mcg (57%) and hybrid cross Fcj × Mcg (61.67%). The lowest survival rate (41.16%) was recorded in parental cross Fcj × Mcj. The hybrid cross Fcj × Mcg expressed the highest growth performances close to those of parental cross Fcg × Mcg, unlike parental cross Fcj × Mcj. Size heterogeneity was greater in hybrids. In all crosses, the condition factor K was low (0.58 to 0.85%), the length-weight relationship was significant with determination coefficient R2 greater than 0.9. The growth was of the negative allometric type (with b less than 3). Positive heterosis has been recorded for both survival and growth at all stages of development. It was concluded that C. jaensis × C. gariepinus hybridizations are indeed possible and would contribute to improve Clarias fry production in captivity. However, the pure strains of Clariidae remain endangered in the natural environment

Influence of Processing Methods on Proximate Composition and Dieting of Two Amaranthus Species from West Cameroon

The effects of various processing methods on the proximate composition and dieting of Amaranthus hybridus and Amaranthus cruentus from West Cameroon were investigated in this study. Both amaranths leaves were subjected to same treatments (sun-dried and unsliced, sliced and cooked), milled, and analysed for their mineral and proximate composition. Thirty-Six Wistar albino rats of 21 to 24 days old were distributed in six groups and fed for 14 days with 10% protein based diets named D0 (protein-free diet), DI (egg white as reference protein), DII (sun-dried and unsliced A. hybridus), DIII (cooked and sliced A. hybridus), DIV (sun-dried and unsliced A. cruentus), and DV (cooked and sliced A. cruentus). The protein bioavailability and haematological and biochemical parameters were assessed in rats. The results showed that K, P, Mg, Zn, and Fe had the higher content in both samples regardless of processing method. The sun-dried and unsliced A. cruentus contained the highest value of crude protein 32.22 g/100 g DM (dry matter) while the highest crude lipid, 3.80 and 2.58%, was observed, respectively, in sun-dried and unsliced A. hybridus and cooked and sliced A. cruentus. Cooked and sliced A. hybridus and A. cruentus contained high crude fiber of 14 and 12.18%, respectively. Rats fed with diet DIII revealed the best protein bioavailability and haematological parameters whereas 100% mortality rate was recorded with group fed with diet DIV. From this study, it is evident that cooked and sliced A. hybridus and A. cruentus could play a role in weight reduction regimes

Antidiabetic potential of methanol extracts from leaves of Piper umbellatum L. and Persea americana Mill.

Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana) (traditionally used in Cameroon against diabetes) on α -glucosidase, β -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from (1.07 ± 0.03) to (31.77 ± 1.17) μg/mL. Among the tested extracts, P. americana was the most active against sensitive enzymes (IC50 of 1.07 ± 0.03 to 15.63 ± 1.23). But, none of the extracts showed interesting inhibitory effect against β -glucosidase as their percentage inhibitions were less than 16%. From gas chromatography-mass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P. americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes

Effect of Fractioning on Antibacterial Activity of Enantia chlorantha

Infectious diseases caused by bacteria constitute the main cause of morbidity and mortality throughout the world and mainly in developing countries. In this work, the influence of fractioning and the mode of action of stem barks methanol extract of Enantia chlorantha were investigated. The aim was to optimize the antibacterial activity of the methanol extract. The extract was prepared by maceration of barks powder in methanol. Fractioning was done using increasing solvents polarity. Standard phytochemical methods were used for phytochemical screening. Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) of the methanol extract and fractions were determined using broth microdilution method. The studied mode of action of both methanol extract and n-butanol fraction included antibiofilm activity, H+-ATPase-mediated proton pumping assay, salt tolerance, and cells cycle. The methanol extract of E. chlorantha stem barks was found to be active on all the bacteria tested (32 ≤ MIC ≤ 512 μg/mL), its activity being significant (MIC < 100 μg/ml) out of 5 of the 28 clinical isolates used. Salmonella enterica serovar paratyphi A was the most sensitive (32 μg/mL). Compared to the extract and other fractions, the n-butanol fraction was found to be more active (32 ≤ MIC ≤ 256). Significant antibacterial activity of this fraction was observed out of 10 of the 28 bacterial isolates and 3 out of 7 bacterial strains. Lowest MIC values (32 μg/ml) of this fraction were obtained with Escherichia coli (136), Pseudomonas aeruginosa (CIP 76110), and Salmonella enterica serovar typhi 9. The methanol extract of E. chlorantha and its n-butanol fraction revealed several modes of action including the prolongation of the latency phase of the bacterial growth, the inhibition of the pump with protons H+ - ATPases bacterial, the loss of the salt tolerance of the Staphylococcus aureus, and inhibition of the formation of the bacterial biofilm. The present results showed that the n-butanol fraction of the methanol stem barks extract of E. chlorantha possess the essential antibacterial components and could best be used to fight against bacterial infections as compared to methanol extract

Effect of fractioning on antibacterial activity of n-butanol fraction from Enantia chlorantha stem bark methanol extract

Abstract Background Enantia chlorantha is a plant belonging to Annonaceae Family. The Barks and leaves are used traditionally to treat infectious diseases. Earlier studies highlighted the antibacterial activity of stem barks methanol extract. This study is thus aimed at investigating the effect of fractionation on antibacterial activity of its n-butanol fraction. Methods The extract of E. chlorantha stem barks was obtained by maceration in methanol and then subjected to a liquid/liquid partition by successive depletion with solvents of increasing polarity. The n-butanol fraction was fractionated by adsorption chromatography on silica gel. A product was isolated from the dichloromethane/methanol (2%) fraction and the structure was determined on the basis of spectroscopic data; Proton Nuclear Magnetic Resonance (1H NMR), Carbon-13 Nuclear Magnetic Resonance (13C NMR), Heteronuclear Multiple Bond Correlation (HMBC), H-correlation spectroscopy (H-COSY), attached proton test (APT), heteronuclear multiple quantum coherence (HSQC). The antibacterial activity was evaluated by broth microdilution method against six reference strains and eight clinical bacterial strains. Results The n-butanol fraction was found to be active with MIC values ranging from 32 to 256 μg/mL. The FA sub-fraction was more efficient among the eight sub-fractions, the n-butanol fraction and comparable to Chloramphenicol used as reference antibiotic. The product obtained was elucidated as palmitin. The antibacterial activity of the latter was comparable to that of Chloramphenicol on one reference strain and 4 of the 6 clinical strains. Conclusion The FA sub-fraction had better antibacterial activity than the n-butanol fraction and other sub-fractions, and possibly palmitin was the active substance responsible for the antibacterial activity of E. chlorantha