Clove oil prevents glycyrrhizin gel formation in aqueous solution.
One persistent problem with using therapeutic concentrations of glycyrrhizin (GZ) is that, at these high concentrations, it forms a gel in an aqueous solution. We previously solved this problem by dissolving GZ in a highly concentrated phosphate buffer. Unfortunately, the resulting GZ solution has a hyperosmotic pressure that renders it unsuitable for use in patients. The aim of this study was to prepare a highly concentrated GZ solution having an osmotic pressure ratio of 1 and a pH of 7.4. By adding small amounts of oil and using a 100 mM phosphate buffer, we achieved an emulsified GZ solution that is stable at room temperature and has a physiological osmotic pressure and pH. When clove oil was used as an emulsifier, the gel formation temperature of GZ solution decreased appreciably compared to that of GZ solution without clove oil. Using scanning electron microscopy (SEM), we examined the detailed characteristics of GZ gels prepared from solutions with or without clove oil. SEM of cross sections of GZ gels revealed an irregular structure in gels prepared with clove oil, indicating that clove oil prevented the formation of the intermolecular GZ networks typically characterized by gels derived from pure GZ solutions. (+info)
Essential oils against foodborne pathogens and spoilage bacteria in minced meat.
Techniques of celloidin removal from temporal bone sections.
OBJECTIVES: We sought to determine whether the technique of celloidin removal influences the results of immunostaining in celloidin-embedded cochleae. METHODS: We compared four protocols of celloidin removal, including those using clove oil, acetone, ether-alcohol, and methanol saturated with sodium hydroxide. By optimally fixing our tissue (perfused mice), and keeping constant the fixative type (formalin plus acetic acid), fixation time (25 hours), and decalcification time (ethylenediaminetetraacetic acid for 7 days), we determined whether the technique of celloidin removal influenced the immunostaining results. Six antibodies were used with each removal method: prostaglandin D synthase, sodium, potassium adenosine triphosphatase (Na+,K(+)-ATPase), aquaporin 1, connective tissue growth factor, tubulin, and 200 kd neurofilament. RESULTS: Clove oil, acetone, and ether-alcohol resulted in incomplete removal of the celloidin, thereby negatively affecting the results of immunostaining. The methanol-sodium hydroxide method was effective in completely removing the celloidin; it produced the cleanest and most reproducible immunostaining for all six antibodies. CONCLUSIONS: Freshly prepared methanol saturated with sodium hydroxide and diluted 1:2 with methanol was the best solvent for removing celloidin from mouse temporal bone sections, resulting in consistent and reproducible immunostaining with the six antibodies tested. (+info)
Protective effect of clove oil-supplemented fish diets on experimental Lactococcus garvieae infection in tilapia.
The essential oils extracted from the four herbs, cinnamon (Cinnamomum verum), clove (Syzygium aromaticum), ginger (Zingiber officinale) and holy basil (Ocimum sanctum), were investigated for their antimicrobial activity and mode of action against Lactococcus garvieae, a fish pathogenic bacteria causing lactococcosis. Of all the tested oils, clove oil had the strongest inhibitory effect and exhibited a bactericidal mode of action against the pathogenic bacterium. When an intraperitoneal infection of tilapia (Oreochromis niloticus) with L. garvieae was performed, the median lethal dose (LD(50)) was determined to be 1.78x10(2) CFU/fish. For an in vivo trial, no mortality was apparent in fish fed on the fish diets supplemented with 3% (w/w) of clove oil and with 0.5% (w/w) of oxytetracycline 5 d prior to the infection with L. garvieae. These results indicate that clove oil had a protective effect on experimental L. garvieae infection in tilapia and the potential to replace antibiotics for controlling the disease. (+info)
Comparative anticancer potential of clove (Syzygium aromaticum)--an Indian spice--against cancer cell lines of various anatomical origin.
Spices, active ingredients of Indian cooking, may play important roles in prevention and treatment of various cancers. The objective of the present study is to compare the in vitro anticancer activities of three different extracts of Clove (Syzygium aromaticum L), a commonly used spice and food flavouring agent, against different kinds of cancer cell lines of various anatomical derivations. Water, ethanol and oil extracts were screened for anti proliferative activity against HeLa (cervical cancer), MCF-7 (ER + ve) and MDA-MB-231 (ER - ve) breast cancer, DU-145 prostate cancer and TE-13 esophageal cancer cell lines, along with normal human peripheral blood lymphocytes. Inhibition of cell proliferation was assessed using MTT assay as a vital stain. In the examined five cancer cell lines, the extracts showed different patterns of cell growth inhibition activity, with the oil extract having maximal cytotoxic activity. Morphological analysis and DAPI staining showed cytotoxicity to be a result of cell disruption with subsequent membrane rupture. Maximum cell death and apoptotic cell demise occurred in TE-13 cells within 24 hours by clove oil at 300 mul/ml with 80% cell death whereas DU-145 cells showed minimal cell death. At the same time, no significant cytotoxicity was found in human PBMC's at the same dose. (+info)
Influence of clove oil on certain quorum-sensing-regulated functions and biofilm of Pseudomonas aeruginosa and Aeromonas hydrophila.
Quorum sensing (QS) plays an important role in virulence, biofilm formation and survival of many pathogenic bacteria including Pseudomonas aeruginosa. This signalling pathway is considered as novel and promising target for anti-infective agents. In the present investigation, effect of the Sub-MICs of clove oil on QS regulated virulence factors and biofilm formation was evaluated against P. aeruginosa PAO1 and Aeromonas hydrophila WAF-38 strain. Sub-inhibitory concentrations of the clove oil demonstrated statistically significant reduction of las- and rhl-regulated virulence factors such as LasB, total protease, chitinase and pyocyanin production, swimming motility and exopolysaccharide production. The biofilm forming capability of PAO1 and A. hydrophila WAF-38 was also reduced in a concentration-dependent manner at all tested sub-MIC values. Further, the PAO1-preinfected Caenorhabditis elegans displayed an enhanced survival when treated with 1.6 percent v/v of clove oil. The above findings highlight the promising anti-QS-dependent therapeutic function of clove oil against P. aeruginosa. (+info)
A preliminary study of the acaricidal activity of clove oil, Eugenia caryophyllus.