Evaluation of the Anti-microbial Activities of the Extracts of the Leaf and Stem Bark of Alstonia congensis on Some Human Pathogenic Bacteria

Author(s):  
ANNAMALAI MADURAM ◽  
RAJU KAMARAJ

Objectives: The objectives of the study were to study the antibacterial activity for the various extracts of Clausena dentata against human pathogens. Clausena (Rutaceae) is a genus of about 23 species of unarmed trees and shrubs. The stem bark of C. dentata is used in veterinary medicine for the treatment of wounds and sprains. Even though C. dentata has a lot of potential medical uses, the study of microbiological properties is very scarce. Methods: The plant C. dentata was collected from Kadagaman, near Tiruvannamalai, Tamil Nadu, India, and authenticated by Centre for Advanced Study in Botany, University of Madras, Chennai. The dry powder of stem bark was extracted with hexane, chloroform, and methanol. The extracts were subjected to qualitative phytochemical screening and antibacterial activity against human pathogenic bacteria such as Escherichia coli, Salmonella Typhi, Klebsiella pneumonia, Vibrio cholerae, and Staphylococcus aureus and compared with ciprofloxacin. Results: Qualitative chemical tests revealed the presence of various phytochemicals such as alkaloids, glycosides, carbohydrate, proteins and amino acids, phytosterols, and volatile oil. The antibacterial activity result reveals that all the extracts were are more active against V. cholerae. The activity against Pseudomonas aeruginosa was mild. Conclusion: The activity against V. cholerae was comparable with that of 5 μg/mL ciprofloxacin at the concentration of C. dentata 40 μg/mL. The orders of antibacterial activity against human pathogenic bacteria are hexane, methanol, and chloroform extract of C. dentata.


Apmis ◽  
2012 ◽  
Vol 121 (9) ◽  
pp. 827-834 ◽  
Author(s):  
Sanna Huttunen ◽  
Kaisu Riihinen ◽  
Jussi Kauhanen ◽  
Carina Tikkanen‐Kaukanen

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 299
Author(s):  
Reetika Singh ◽  
Christophe Hano ◽  
Gopal Nath ◽  
Bechan Sharma

Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxidant phytochemicals. Here, we expand this traditional usage with the green biosynthesis of silver nanoparticles (AgNPs) achieved using a Carissa carandas L. leaf extract as a reducing and capping agent. The green synthesis of AgNPs reaction was carried out using 1mM silver nitrate and leaf extract. The effect of temperature on the synthesis of AgNPs was examined using room temperature (25 °C) and 60 °C. The silver nanoparticles were formed in one hour by stirring at room temperature. In this case, a yellowish brown colour was developed. The successful formation of silver nanoparticles was confirmed by UV–Vis, Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The characteristic peaks of the UV-vis spectrum and XRD confirmed the synthesis of AgNPs. The biosynthesised AgNPs showed potential antioxidant activity through DPPH assay. These AgNPs also exhibited potential antibacterial activity against human pathogenic bacteria. The results were compared with the antioxidant and antibacterial activities of the plant extract, and clearly suggest that the green biosynthesized AgNPs can constitute an effective antioxidant and antibacterial agent.


2009 ◽  
Vol 4 (1) ◽  
pp. 50-51 ◽  
Author(s):  
Debmalya Barh ◽  
Anil Kumar ◽  
Amarendra Narayana Misra

2019 ◽  
Vol 57 (1) ◽  
pp. 7
Author(s):  
Duc Long Le ◽  
Huu Tung Nguyen ◽  
Thi Thom Nguyen ◽  
Gyung Ja Choi ◽  
Dinh Hoang Vu ◽  
...  

Abstract-HCTN_16Methanol extract of the roots of Scutellaria baicalensis effectively inhibited the bacterial growth of human pathogenic bacteria Staphylococcus aureus ATCC 6538, Bacillus cereus ATCC 21768 and Bacillus subtilis ATCC 6633 at MICs of 2,000 µg/mL. n-Hexane, ethyl acetate and aqueous residues were prepared by successively partitioning the methanol extract with n-hexane and ethyl acetate. Among them, only ethyl acetate layer showed antibiotic effect; whereas n-hexane and aqueous layers were inactive against tested bacteria. The ethyl acetate residue was fractionated by silica gel column chromatography to afford three flavonoids and an oligosaccharide. Their chemical structures were elucidated as wogonin (SB1), baicalein (SB4), baicalin (SB5) and tetrasaccharide (SB10) on the basis of the analysis of NMR and MS spectroscopic data. The isolates were evaluated for in vitro inhibitory effect against human pathogenic bacteria using micro dilution bioassay method. Baicalein (SB4) showed a broad-spectrum inhibition against various human pathogenic bacteria. In particular, it was found to potently inhibit S. aureus ATCC 6538 and B. cereus ATCC 21768 with MICs of 9.5 and 38 µg/mL, respectively. The study results demonstrated antibiotic effect of the extracts from the roots of S. baicalensis and characterization of compounds isolated from the plant materials.


Author(s):  
ARPITHA SHIVAMALLU ◽  
SHAILASREE SEKHAR

Objectives: The aim of this study was to evaluate the antioxidant, anti-inflammatory, and anti-cancer potencies of the Delonix regia bark, a first of its kind. Methods: The bark was extracted sequentially in Soxhlet apparatus with hexane, chloroform, and methanol in the increasing order of polarity. These extracts were subjected to find its antioxidant activity and total phenol content. Antibacterial activity against human pathogenic bacteria was tested. The anti-inflammatory properties were elucidated by its capacity to inhibit 15-lipoxygenase (LOX) and human cyclooxygenase (COX)-2. Cell cytotoxic capacity was evaluated against MCF-7 cells breast cancer cell lines. Results: Liquid chromatography (LC)-Mass Spectroscopy (MS) fingerprint of the methanol extract identified a total of 14 polyphenols, of which five were structurally characterized based on their mass-charge ratio [M-H]− peak, UV-vis absorption in comparison to published data. Antibacterial activity by disk diffusion inhibited human pathogenic bacteria. Bacterial biofilm inhibition capacity of extract (750 mg) imaged by confocal laser scanning microscopy revealed loss of microcolonies. Extract when tested for 15-LOX inhibition exhibited IC50 values of 94.5 ± 1.23 mg.mL−1 by enzyme kinetics studies using spectrophotometric techniques. Similarly, it could inhibit COX-2 enzyme at relatively lower concentrations (32.18 ± 1.91 mg.mL−1). Further, it quenched free radicals produced by Fentons’ reagent studied by DNS-nicking assay indicating its strong antioxidant property with the capacity to protect DNA. In vitro cytotoxicity was evaluated by 3-(4,5-dimethylthylthiazol-2-yl)-2,5-diphynyl tetrazolium bromide assay and apoptosis induced in MCF-7 cells was assessed morphologically. Conclusion: Our data suggest that D. regia bark methanol extract exerts its therapeutic activity for further pharmaceutical evaluations. Further studies are necessary to determine the mechanisms of these pharmacological properties.


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