ABSTRACT
OBJECTIVE：To study the anti-inflammatory effects of Yuyang capsule on bacterial dermatitis model rats and its effect on TLR/NF-κ B pathway. METHODS：Minimum inhibition concentration （MIC）and minimal bactericidal concentration （MBC）of Yuyang capsule against Staphylococcus aureus were determined by microdilution test. Totally 50 SD rats were randomly divided into model group ，positive control group （amoxicillin and clavulanate potassium ，120 mg/kg as amoxicillin ），Yuyang capsules high-dose ，medium-dose and low-dose groups （according to MIC ），with 10 rats in each group. The model of bacterial dermatitis was established by using the burned skin of rats infected with S. aureus . 24 h after modeling ，administration groups were intragastrically given the corresponding drug ，and model group was intragastrically given the same amount of normal saline ，once a day，for consecutive 7 days. The skin healing rate was calculated on the 1st，3rd，5th and 7th day of administration ，and the scab formation，decrustation and healing were recorded. The contents of IL- 1β，IL-6，IL-10，TNF-α，hydroxyproline（HYP），collagen Ⅰ（Col Ⅰ）and Col Ⅲ in skin tissue were detected by ELISA. Morphology changes of skin tissues were observed by HE staining. The ultrastructure was observed by transmission electron microscope. Protein expression of TLR 2，TLR4 and p-NF-κB p65 were detected by Western blotting assay. RESULTS ：MIC and MBC of Yuyang capsule were 25 mg/mL and 50 mg/mL，respectively. Dose of Yuyang capsules high-dose ，medium-dose and low-dose groups were set at 600，300，150 mg/kg. Compared with model group，scab appeared on the injured skin 3 days after administration in Yuyang capsule high-dose and medium-dose groups ，and decrustation appeared on the injured skin of part mice 5-7 days after administration ；the skin healing rate of the positive control group，Yuyang capsule high-dose and medium-dose groups were all significantly increased at each time point. The contents of IL- 1 β，IL-6，IL-10 and TNF-α，pathological score ，protein expression of TLR 2，TLR4 and p-NF-κB p65 were decreased significantly （P＜0.05 or P＜0.01）；the pathological changes such as inflammatory cell infiltration in skin tissue were improved. The contents of HYP，Col Ⅰ and Col Ⅲ were increased significantly in positive control group and Yuyang capsule high-dose group （P＜0.05 or P＜0.01）. There was no statistical significance in most above indexes in positive control group ，Yuyang capsule high-dose and medium-dose groups （P＞0.05）. CONCLUSIONS ：Yuyang capsule can promote skin healing of bacterial dermatitis model rats and shows certain anti-inflammatory effects ；the mechanism may be related to inhibiting TLR/NF-κB signaling pathway and reducing inflammatory response.
ABSTRACT
The antibacterial and antibiofilm activities of crude extract of Lasiodiplodia pseudotheobromaeIBRL OS-64 was studied and tested against a foodborne pathogenic bacterium, Yersinia enterocolitica. The ethylacetate extract exhibited favorable antibacterial activity with the zone of inhibition was 20.3±0.6 mm compared to dichloromethane (15.0±0.3 mm) and butanol (9.0±0.3 mm) extracts. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of the extract were 125 and 250 μg/mL, respectively. Structural degeneration studies through scanning electron microscopy (SEM) and transmission electron microscope (TEM) micrographs exhibited major abnormalities that occurred on thebacterial cells after exposureto the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The findings showed that the extract possesses antibiofilm activity against the initial and preformed biofilm of Y. enterocoliticawith the highest inhibition value of 69.12% and 58.70%, respectively The results also revealed the initial biofilm was more susceptible to the extract as compared to pre-formed biofilm. The light microscopy (LM) and SEM photomicrographs proved that thefungal extract significantly eliminates extracellular polysaccharide (EPS) matrices and hinder the attachment of the bacterial cells for biofilm formation. Therefore, the current study suggested the ethyl acetate crude extract from an endophytic fungus, L. pseudotheobromae IBRL OS-64 may be an effective antibacterial and anti-biofilm agent to treat foodborne pathogens
ABSTRACT
Aims: This study was designed to evaluate the antimicrobial activity of five essential oils (EOs) extracted from the aerial parts (leaves and flowering tops) of three species growing in the north of Morocco: Origanum elongatum, Thymus capitatus and Mentha suaveolens. Study Design: Chemical analysis of EOs, antibacterial and antiviral activities of EOs. Place and Duration of Study: Department of Biology (Faculty of Sciences), Institute of Agrochemistry and Food Technology (IATA), between September 2009 and December 2009. Methodology: The EO constituents were extracted by hydrodistillation and analysed by GC-MS. The antibacterial activity of EOs was tested against three reference strains, Salmonella enterica subsp. enterica CECT 915T, Listeria monocytogenes CECT 4031T, and Escherichia coli O157:H7 CECT 4267, and two food isolated strains Salmonella sp. S64 and Listeria monocytogenes L23, using the diffusion method and the microtitration assays. The antiviral effect of EOs was evaluated for the inactivation of murine norovirus (MNV-1), a human norovirus surrogate. Results: GC and GC/MS analyses revealed that thyme EO predominantly contains carvacrol (58.77-68.63%), p-cymene (4.84-5.63%), γ-terpinene (2.78-3.75%) and β- caryophyllene (2.62-2.91%). Oregano EO was mainly constituted by carvacrol (19.21- 40.12%), thymol (3.57-14.24%), p-cymene (16.08-16.19%) and γ-terpinene (7.27- 13.48%). While, mint EO was characterized by piperitenone oxide (41.84%), (-)-isopulegol (11.95%) and limonene (7.35%). All extracts exhibited an antibacterial activity at different levels against strains reported as the causal agents of foodborne diseases, but a low antiviral activity (0.87-0.50 log10 TCID50/ml reduction) was observed. Conclusion: Results suggest the potential use of tested EOs as bio-preservatives in the food industry. However, their antiviral activity needs to be further investigated.
ABSTRACT
Spices and herbs have been used for many years by different cultures. The aim of the present study is (1) to investigate in-vitro antimicrobial effects of different spices and herbs (5 species: Rosmarinus officinalis (Rosemary), Coriandrum sativum (coriander), Micromeria fruticosa (L.) Druce subsp. Brachycalyx P.H. Davis (White micromeria), Cumium cyminum (cumin), Mentha piperita (Peppermint) against different bacteria and fungi species, and (2) to discuss the in-vitro possible effects between the plants and antibiotics. The microorganisms used were Micrococcus luteus LA 2971, Bacillus megaterium NRS, Bacillus brevis FMC 3, Enterococcus faecalis ATCC 15753, Pseudomonas pyocyaneus DC 127, Mycobacterium smegmatis CCM 2067, Escherichia coli DM, Aeromonas hydrophila ATCC 7966, Yersinia enterocolitica AU 19, Staphylococcus aureus Cowan 1, Streptococcus faecalis DC 74 bacteria, and Saccharomyces cerevisiae WET 136, Kluvyeromyces fragilis DC 98 fungi in this study. The results indicated that essential oils of Rosmarinus officinalis, Coriandrum sativum L., Micromeria fruticosa (L.) Druce subsp. brachycalyx P.H. Davis, Cumium cyminum L., Mentha piperita L. were shown antimicrobial activity in the range of 7-60 mm 2 Cl-1 inhibition zone to the microorganisms tested, using disc diffusion method. Standard antibiotic such as Gentamicin (10 Cg), Cephalothin (30 Cg), Ceftriaxone (10 Cg), Nystatin (10 U) discs were used for comparison with the antimicrobial activities of essential oils of these plants. In addition, antibacterial activity of essential oils of these plants was researched by effects when it was used together with these standard antibiotics in vitro. However, antibacterial activity changed also by in vitro interactions between these standard antibiotics and essential oils of these plants. Synergic, additive or antagonist effects were observed in antibacterial activity.
ABSTRACT
In the present study, a total of six extracts of two spices namely black pepper and turmeric in three solvents were evaluated for their antibacterial and antifungal activity. The antibacterial activity was measured by agar well diffusion method and antifungal activity by poisoned food technique. All the extracts showed antibacterial activity against all the test bacterial isolates. Aqueous extracts of black pepper did not exhibit antibacterial activity against B. subtilis. In aqueous extract, black pepper and turmeric showed good inhibitory activity against Staphylococcus aureus with zone of inhibition 25mm to 30mm and 26mm to 28mm respectively. In ethanolic extract, black pepper extract showed antibacterial activity against all test bacteria with zone of inhibition ranged between 15mm and 22mm while turmeric showed activity with zone of inhibition ranged between 13mm and 24mm. In methanolic extract, the diameter of zone of inhibition ranged between 12mm and 28mm in black pepper and 13mm and 22mm in turmeric. In case of antifungal activity, only turmeric ethanolic extract showed activity only against Rhizopus stolonifer and Mucor sp. with percent mycelial growth inhibition ranged between 25% and 30%. Based on this finding, these extracts may be an alternative to chemical preservatives and used as natural antimicrobial preservatives to reclaim the shelf-life of food.