Extraction of essential oil from Nigella sativa using supercritical carbon dioxide : study of antibacterial activity.

The antimicrobial activity of N. sativa essential oil obtained by supercritical fluid extraction by carbon dioxide was investigated against Gram Positive and Gram negative strains, isolated from clinical specimens. Best conditions for Black cumin oil extraction are obtained at 400 bar, 40°C and a solvent flow rate of 25 g min-1. The seed extracts were prepared by supercritical fluid extraction method. Filter paper discs impregnated with varying concentrations of N. sativa extract were tested by the disk diffusion method. Methicillin Resistant Staphylococcus Aureus (MRSA) ATCC strain (700968), E. coli ATCC strain (25922), E. coli 0157 ATCC strain (12799), Extended-Spectrum Beta-Lactamase (ESBL) Klebsiella pneumoniae ATCC strain (700603), Carbapenam Resistant acenitobacter Baumanii (CRAB) clinical strain and Vibrio cholerae 01 Ogawa and 0139 Bengal clinical strains were investigated. The inhibition zones of the Mueller Hinton agar in different extract concentrate ion showed that at 25 mg 20 μL-1, 50 mg 20 μL-1 and 100 mg 20 μL-1, the inhibition zones increased accordingly in S. aureu. However, N. sativa was found to be inactive against ESBL producers (E. coli and K. pneumoniae)

Characterization of Nigella sativa L. essential oil-loaded solid lipid nanoparticles

Problem statement: Seeds of Nigella sativa L., commonly known as black seed, have been used in traditional medicine by many Asian, Middle Eastern and Far Eastern Countries to treat headache, coughs, abdominal pain, diarrhea, asthma, rheumatism and other diseases. The seeds of this plant are the most extensively studied, both phytochemically and pharmacologically. The aqueous and oil extracts of the seeds have been shown to possess especially nowadays in pharmaceutical antioxidant, anti-inflammatory, anticancer, analgesic, antimicrobial activities and medicinal and cosmetic applications, sanitary, cosmetic, agricultural and food industries. Approach: The aim of this study was to formulate a new delivery system for dermal and cosmetic application by the incorporation of Nigella sativa essential oil into solid lipid nanoparticles SLN. SLN formulations were prepared following the high-pressure homogenization after starring and ultra-trax homognization techniques using hydrogenated palm oil Softisan 154 and N. sativa essential oil as lipid matrix, sorbitol and water as surfactants. The SLN formulation particle size was determined using Photon Correlation System (PCS). Results: The change of particle charge was studied by Zeta Potential (ZP) measurements, while the melting and re-crystallization behavior was studied using Differential Scanning Calorimetry (DSC). Data showed a high physical stability for both formulations at various storage temperatures during 3 months of storage. In particular, average diameter of N. sativa essential oil-loaded SLN did not vary during storage and increased slightly after freeze-drying the SLN dispersions. Conclusion: Therefore, obtained results showed that the studied SLN formulations are suitable carriers in pharmaceutical and cosmetic fields

Cloning and Immunological Characterization of Recombinant Vibrio Cholerae O-Antigen Transport Protein Expressed in Lactococcus Lactis

The food grade Lactococcus lactis is a potential vehicle for protein delivery via the oral route. This study used lactococcal strains as models for producing the wzm gene that codes for the porin protein involved in transport of Vibrio cholerae lipopolysaccharide O-antigen. The 750 bp gene fragment was PCR-amplified from Vibrio cholerae O1 clinical isolates and cloned into the L. lactis nisin-controlled gene expression vector pNZ8048. The constructs were electrotransformed into L. lactis NZ9000 host strains where transcription of the gene on the RNA level was confirmed by reverse transcriptase PCR. Sequence comparison and multiple alignment of the translated cDNA nucleotides with that of known proteins reveal the presence of conserved structural domains of the ABC-2 membrane superfamily integral membrane protein component. Due to its hydrophobic nature, whole cell L. lactis protein extract was subjected to solubilisation with the detergents sodium dodecyl sulfate (SDS) and Triton X-100 before being separated on SDS-PAGE and analysed on Western blot. In the case of the current study, solubilisation using SDS was found to be more efficient when compared to Triton X-100 in retrieving the expressed ≈ 34 kDa wzm porin as observed upon western blot analysis. ELISA readings showed that oral administration of recombinant L. lactis into New Zealand White rabbits elicited a statistically significant increase of both IgG and IgA levels (P < 0·05) when compared to the control group given only the preparation buffer. Challenge study with virulent V. cholerae O1 strains via the oral route evoked watery diarrhoea in rabbits given only the buffer throughout the immunization period, but fecal passing of both the recombinant and non-recombinant L. lactis groups were normal. This indicates a positive effect of the Lactococcal cells itself, probably towards the intestinal microbiota, in protecting against the adverse effects of V. cholerae and in evading diarrhoea. The diarrhoea lasted approximately two days in the control group, while the others were observed to be diarrhoea-free until the end of the study. Bioinformatics and molecular methods have enabled prediction and detection of the wzm protein product which, as shown in this study, possesses the potential to elicit antibody production and enhance immunity. Administration of the L. lactis bacterium through the oral route was shown to increase mucosal immunity and assist in conferring protection against the diarrhoeal-causing disease cholera. These results provide more insight into the relatively unknown product of V. cholerae wzm, while providing a potential alternative for health improvement against cholera that could be further developed for a safer, convenient, and effective method in protection and prevention of this disease

Distribution, Prevalence, and Antibiotic Susceptibility Profiles of Infectious Noncholera Vibrio Species in Malaysia

Background. The noncholera Vibrio spp. which cause vibriosis are abundantly found in our water ecosystem. These bacteria could negatively affect both humans and animals. To date, there is a paucity of information available on the existence and pathogenicity of this particular noncholera Vibrio spp. in Malaysia in comparison to their counterpart, Vibrio cholera. Methods. In this study, we extracted retrospective data from Malaysian surveillance database. Analysis was carried out using WHONET software focusing noncholera Vibrio spp. including Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio fluvialis, Vibrio alginolyticus, Vibrio hollisae (Grimontia hollisae), Vibrio mimicus, Vibrio metschnikovii, and Vibrio furnissii. Results. Here, we report the first distribution and prevalence of these species isolated in Malaysia together with the antibiotic sensitivity profile based on the species. We found that V. parahaemolyticus is the predominant species isolated in Malaysia. Noticeably, across the study period, V. fluvialis is becoming more prevalent, as compared to V. parahaemolyticus. In addition, this study also reports the first isolation of pathogenic V. furnissii from stool in Malaysia. Conclusion. These data represent an important step toward understanding the potential emergence of noncholera Vibrio spp. outbreaks