The effect of leaves extracts of Clitoria ternatea Linn against the fish pathogens

Cationic Clitoria ternatea Seed Peptide as a Potential Novel Bioactive Molecule

BACKGROUND

While several biologics have been reported from different parts of Clitoria ternatea, a herbaceous climber of the family Fabaceae, specific production of cationic peptides other than cyclotides (<3.7 kDa) has barely been investigated or their bioactive potential looked into.

OBJECTIVE

To uncover potential bioactivities and characteristics of novel cationic peptides from C. ternatea seeds.

METHODS

C. ternatea seed cationic peptide purified by simple and cost-effective procedures was analyzed by electrophoresis and mass spectrometry. Antimicrobial efficacy was evaluated against bacterial and fungal pathogens. Antioxidant potential was quantified by in vitro antioxidant assays. Physicochemical characterization and Tandem mass spectrometry were performed.

RESULTS

An 8.5 kDa cationic peptide purified from C. ternatea seeds was active against Candida albicans, Staphylococcus aureus, Aeromonas hydrophila and Escherichia coli at a minimum inhibitory concentration in the range of 8-32 μg/ml. This activity was totally uncompromised at pH 5-8 or after 1 h of heat treatment at 70-80 ºC, but was sensitive to protease treatment. Concentration-dependent free-radical scavenging activity and ferric-reducing capacity demonstrated the antioxidant potential of the peptide. Tandem MS analysis of trypsin-digested peptide based on shotgun proteomics detected matching peptide sequences with one or two cysteine residues but had low sequence coverage (≤17%) to known sequences in the C. ternatea protein database. Taken together, the distinct characteristics of this novel 8.5 kDa peptide clearly distinguishes it from known cyclotides of C. ternatea.

CONCLUSIONS

Insights have been obtained into the functional characteristics of what appears to be a novel cationic peptide from C. ternatea seeds, exhibiting significant antimicrobial and antioxidant activities.

Biosynthesized Fe- and Ag-doped ZnO nanoparticles using aqueous extract of Clitoria ternatea Linn for enhancement of sonocatalytic degradation of Congo red

Nowadays, the current synthesis techniques used in industrial production of nanoparticles have been generally regarded as nonenvironmentally friendly. Consequently, the biosynthesis approach has been proposed as an alternative to reduce the usage of hazardous chemical compounds and harsh reaction conditions in the production of nanoparticles. In this work, pure, iron (Fe)-doped and silver (Ag)-doped zinc oxide (ZnO) nanoparticles were successfully synthesized through the green route using Clitoria ternatea Linn. The optical, chemical, and physical properties of the biosynthesized ZnO nanoparticles were then analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), UV-Vis diffuse reflectance spectroscopy (DRS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and surface analysis. The biosynthesized ZnO nanoparticles were crystallized with a hexagonal wurtzite structure and possessed smaller particle sizes than those of commercially or chemically produced samples. The existence of biomolecules to act as reducing and stabilizing agents from C. ternatea Linn aqueous extract was confirmed using FTIR analysis. The biosynthesized ZnO nanoparticles mainly comprised of negatively charged groups and responsible for moderately stable dispersion of the nanoparticles. All these properties were favorable for the sonocatalytic degradation of Congo red. Sonocatalytic activity of ZnO nanoparticles was studied through the degradation of 10 mg/L Congo red using ultrasonic irradiation at 45 kHz and 80 W. The results showed that the sonocatalytic degradation efficiency of Congo red in the presence of biosynthesized ZnO nanoparticles prepared at 50 °C for 1 h could achieve 88.76% after 1 h. The sonocatalytic degradation efficiency of Congo red in the presence of Ag-doped ZnO was accelerated to 94.42% after 10 min which might be related to the smallest band gap energy (3.02 eV) and the highest specific surface area (10.31 m²/g) as well as pore volume (0.0781 cm³/g). Lastly, the biosynthesized ZnO nanoparticles especially Ag-doped ZnO offered significant antibacterial potential against Escherichia coli which indicated its ability to inhibit the normal growth and replication of bacterial cells. These results affirmed that the biosynthesized ZnO nanoparticles could be used as an alternative to the current chemical compounds and showed a superior sonocatalytic activity toward degradation of Congo red.

Development of a colloidal gold immunochromatographic strip for rapid detection of Streptococcus agalactiae in tilapia

A colloidal gold immunochromatographic strip was developed for rapid detection of Streptococcus agalactiae (S. agalactiae) infection in tilapia. The monoclonal antibodies (mAb) 4C12 and 3A9 were used to target S. agalactiae as colloidal gold-mAb conjugate and captured antibody, respectively. The colloidal gold immunochromatographic strip was assembled via routine procedures. Optimal pH and minimum antibody levels in the reaction system for gold colloidal-mAb 4C12 conjugation were pH 7.4 and 18μg/mL, respectively. Optimal concentrations of the captured antibody 3A9 and goat anti-mouse antibody were 0.6mg/mL and 2mg/mL, respectively. The sensitivity of the strip for detecting S. agalactiae was 1.5×10⁵ colony forming units (CFU). No cross-reaction was observed with other commonly encountered bacteria, including Pseudomonas fluorescens, Aeromonas hydrophila, Vibrio anguillarum and Streptococcus iniae. The assay time for S. agalactiae was less than 15min. Tilapia samples artificially infected with S. agalactiae were tested using the newly developed strip. The results indicated that blood, brain, kidney, spleen, metanephros and intestine specimens of infected fish can be used for S. agalactiae detection. The validity of the strip was maintained for 6 months at 4°C. These findings suggested that the immunochromatographic strip was effective for spot and rapid detection of S. agalactiae infected tilapia.

Antifungal activity of Aegle marmelos (L.) Correa (Rutaceae) leaf extract on dermatophytes

OBJECTIVE

To evaluate the in vitro antifungal activity of Aegle marmelos leaf extracts and fractions on the clinical isolates of dermatophytic fungi like Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis, Microsporum gypseum and Epidermophyton floccosum.

METHODS

The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of various extracts and fractions of the leaves of Aegle marmelos were measured using method of National Committee for Clinical Laboratory Standards (NCCLS).

RESULTS

Aegle marmelos leaf extracts and fractions were found to have fungicidal activity against various clinical isolates of dermatophytic fungi. The MIC and MFC was found to be high in water and ethyl alcohol extracts and methanol fractions (200µg/mL) against dermatophytic fungi studied.

CONCLUSIONS

Aegle marmelos leaf extracts significantly inhibites the growth of all dermatophytic fungi studied. If this activity is confirmed by in vivo studies and if the compound is isolated and identified, it could be a remedy for dermatophytosis.

Antibacterial activity of leaves and inter-nodal callus extracts of Mentha arvensis L

OBJECTIVE

To determine the anti-bacterial efficacy of chloroform, ethanol, ethyl acetate and water extracts of inter-nodal and leaves derived calli extracts from Mentha arvensis (M. arvensis) against Salmonella typhi(S. typhi), Streptococcus pyogenes(S. pyogenes), Proteus vulgaris(P. vulgaris) and Bacillus subtilis(B. subtilis).

METHODS

The inter-nodal and leaves segments of M. arvensis were cut into 0.5-0.7 cm in length and cultured on Murashige and Skoog solid medium supplemented with 3% sucrose, gelled with 0.7% agar and different concentration of 2, 4-Dichlorophenoxyacetie acid (2,4-D) either alone or in combinations. The preliminary phytochemical screening was performed by Brindha et al method. Antibacterial efficacy was performed by disc diffusion method and incubated for 24 h at 37 °C.

RESULTS

Maximum percentage of callus formation (inter-nodal segments 84.3 ± 0.78; leaves segments 93.8 ± 1.27) was obtained on Murashige and Skoog's basal medium supplemented with 3% sucrose and 1.5 mg/L of 2, 4-D. The ethanol extracts of leaves derived calli showed the maximum bio-efficacy than other solvents. The leaves and stem derived calli extracts on Proteus sp. showed that the plants can be used in the treatment of urinary tract infection associated with Proteus sp. Through the bacterial efficacy studies, it is confirmed that the in vitro raised calli tissue was more effective compared to in vivo tissue.

CONCLUSIONS

The bio-efficacy study confirmed that the calli mediated tissues showed the maximum zone of inhibition. The present study paved a protocol to establish high potential cell lines by in vitro culture.