Effect of Laurus nobilis on bacteria and human transforming growth factor-β1

SUMMARY OBJECTIVE: In this study, we aimed to determine the phenolic compounds, the antibacterial activity of extract from Laurus nobilis leaves, and its possible effect on transforming growth factor-β1 expression level in peripheral blood mononuclear cells. METHODS: The phenolic components of Laurus nobilis were identified by the high-performance liquid chromatography method. The antibacterial activity of this extract was determined by disk diffusion and broth microdilution methods. The transforming growth factor-β1 expression was analyzed using the RT-qPCR method. RESULTS: Epicatechin was found in the highest amount and o-coumaric acid in the lowest amount. The half-maximal inhibitory concentration (IC50) was determined to be 55.17 μg/mL. The zones of inhibition and minimum inhibitory concentration for Staphylococcus aureus, Enterococcus faecalis, and Klebsiella pneumoniae were 15, 14, and 8 mm and 125, 250, and 1000 μg/mL, respectively. The change in transforming growth factor-β1 expression levels was found to be statistically significant compared with the control groups (p<0.0001). CONCLUSION: Laurus nobilis extract was found to be effective against bacteria and altered the expression level of transforming growth factor-β1 in peripheral blood mononuclear cells.

Laurus nobilis L.: assessment of the cytotoxic and genotoxic potential of aqueous extracts by micronucleus and Allium cepa assays

Laurus nobilis L. is a large shrub belonging to the Lauracea family. Its leaves are widely used for food seasoning as well as in folk medicine. Various studies have demonstrated the antiproliferative, antifungal and antibacterial effects of Laurus nobilis, but no studies have investigated the genotoxic effect of the aqueous extract of the plant. The objective of this study was to analyze the genotoxic potential of an aqueous extract of leaves, using the Allium cepa assay and mouse peripheral blood cell micronucleus test. The results showed that the extract did not have any genotoxic activity, but cytotoxic activity was observed in the two experimental models used. The extract had an antiproliferative effect, detected through the reduction of the mitotic index and the polychromatic/normochromatic erythrocyte (PCE/NCE) ratio. The tests also demonstrated a large number of cells undergoing apoptosis and with nuclear abnormalities related to cell death processes. These results can be explained by the presence of phenolic compounds, saponins, flavonoids and alkaloids, detected in the phytochemical analysis of the extract. Therefore, the extract from L. nobilis in the form generally used by the population does not pose risks related to its genotoxic potential, and also contains components with apoptotic and antigenotoxic potential.

Complete essential oils of Laurus nobilisinducing antinociceptiveaction by opioid mechanism in C-Reflex and spinal Wind-Up model in rat / Aceites esenciales totales de Laurus nobilis inducen acción antinociceptivamediante mecanismo opioide en el modelode Reflejo-C y Wind-Up espinal en ratas

The essential oil of Laurus nobilis L. was used to test their antinociceptive efficacy. It was applied intraperitoneally (i.p.) to rats subjected to a nociception test (C reflex and spinal wind-up). The results showed that the essential oil applied at higher doses (0.06 mg/Kg) causes a complete abolition of the spinal wind-up, while the C reflex was unchanged, indicating a clear antinociceptive effect. At lower concentrations (0.012 mg/Kg), there was a lowering in the wind-up by 85% within ten minutes of the essential i.p. oil application. Interestingly, there was an effect of naloxone (0.08 mg/Kg i.p.) When applied, a change occurs that almost entirely reversed the antinociception caused by the essential oil from Laurus nobilis. We conclude that there is a significant antinociceptive effect of the essential oil of Laurus nobilis subjected to electric nociception. In addition, it was observed that naloxone reversed the antinociceptive effect (wind-up) produced by Laurus nobilis.

El aceite esencial de Laurus nobilis L. se usó para probar su eficacia antinociceptiva. Se aplicó por vía intraperitoneal (i.p.) a ratas sometidas a una prueba de nocicepción (reflejo-C y wind-up espinal). Los resultados mostraron que el aceite esencial aplicado a dosis más altas (0.06 mg/Kg) abolió completamente el wind-up espinal, mientras que el reflejo-C no cambió, lo que indica un claro efecto antinociceptivo. A concentraciones más bajas (0.012 mg/Kg), hubo una disminución en el wind-up en un 85% dentro de los diez minutos del i.p. la aplicación del aceite esencial. Curiosamente, hubo un efecto de la naloxona (0.08 mg/Kg i.p.) la cual revierte casi por completo la antinocicepción causada por el aceite esencial de Laurus nobilis. Concluimos que existe un efecto antinociceptivo significativo del aceite esencial de Laurus nobilis sometido a nocicepción eléctrica. Además, se observó que la naloxona revirtió el efecto antinociceptivo (wind-up) producido por Laurus nobilis.

Antibacterial and antibiofilm activities of polysaccharides, essential oil, and fatty oil extracted from Laurus nobilis growing in Lebanon

OBJECTIVE@#To evaluate the antibacterial activity of the extracts of Laurus nobilis against three Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212 and Staphylococcus epidermidis CIP 444) and two Gram-negative bacteria (Escherichia coli ATCC 35218 and Pseudomonas aeruginosa ATCC 27853). Also, the antibiofilm activity has been investigated against the biofilm produced by Staphylococcus epidermidis CIP 444.@*MATERIALS@#The polysaccharides, essential oil, and fatty oils extracted from the plant were used in broth microdilution methods to study the minimal inhibitory concentration, and then the minimal bactericidal concentration was determined.@*RESULTS@#The results showed that alginate, fucoidan, fatty oils and essential oil have good antibacterial activities against the 5 bacterial strains, and a negligible biofilm eradication activity of fucoidan, laminaran, fatty oil, and essential oil was observed, but a promising biofilm eradication activity was obtained with alginate, which showed a reduced biofilm mass even at low concentration.@*CONCLUSIONS@#The extracts obtained have promising antibacterial capacities which need further investigation for them to be incorporated in medical or nutritional applications.

Antibacterial and antibiofilm activities of polysaccharides, essential oil, and fatty oil extracted from Laurus nobilis growing in Lebanon

Objective: To evaluate the antibacterial activity of the extracts of Laurus nobilis against three Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212 and Staphylococcus epidermidis CIP 444) and two Gram-negative bacteria (Escherichia coli ATCC 35218 and Pseudomonas aeruginosa ATCC 27853). Also, the antibiofilm activity has been investigated against the biofilm produced by Staphylococcus epidermidis CIP 444. Materials: The polysaccharides, essential oil, and fatty oils extracted from the plant were used in broth microdilution methods to study the minimal inhibitory concentration, and then the minimal bactericidal concentration was determined. Results: The results showed that alginate, fucoidan, fatty oils and essential oil have good antibacterial activities against the 5 bacterial strains, and a negligible biofilm eradication activity of fucoidan, laminaran, fatty oil, and essential oil was observed, but a promising biofilm eradication activity was obtained with alginate, which showed a reduced biofilm mass even at low concentration. Conclusions: The extracts obtained have promising antibacterial capacities which need further investigation for them to be incorporated in medical or nutritional applications.

Effective antibacterial and antioxidant properties of methanolic extract of Laurus nobilis seed oil.

This study was carried out to determine the in vitro antimicrobial and antioxidant activities of the essential oil, seed oil, and methanolic extract of seed oil obtained from Laurus nobilis L. (Lauraceae). The methanolic extract of seed oil exhibited more effective antibacterial activity comparing to essential oil and seed oil. GC-MS analyses of the essential oil resulted in the identification of 25 compounds. 1.8-Cineol (44.72%), a-Terpinyl acetate (12.95%), Sabinene (12.82%) were the main components. The fatty acid composition was characterized with the high content of linoleic acid (40.79%) and lauric acid (38.08%). The 50% (IC50) inhibition activity of the essential oil on the free radical DPPH was determined as 94.655 mgml-1, whereas IC50 value of methanolic extract of seed oil was found unstable. In the case of the linoleic acid system, oxidation of linoleic acid was inhibited by essential oil and methanolic extract of seed oil, which showed 64.28 and 88.76% inhibition, respectively. The inhibition value of the methanolic extract of seed oil was quite close to the synthetic antioxidant BHT, 92.46% inhibition.