Fifty‐one essential oils extracted from plants of known origin were tested for their antimicrobial activity against three bacteria, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and ...four yeasts, Torulopsis utilis, Schizosaccharomyces pombe, Candida albicans and Saccharomyces cerevisiae using the drop diffusion method. All showed antimicrobial activity against at least one of the micro‐organisms. Following this preliminary screening, 13 essential oils showing antimicrobial activity against at least five of the micro‐organisms were tested in the range 50 μg ml−1 to 500 μg ml−1 using broth micro dilution techniques with dimethylsulphoxide (DMSO) as a dispersing solvent. The concentration of most of the oils required for total inhibition of growth was >500 μg ml−1. Further studies on the antimicrobial action of cinnamon oil in the range 10–150 μg ml−1 showed that 50‐fold higher activity was found when no dispersing solvent was used.
The essential oil extracted from palmarosa (
Cymbopogon martinii) has proven anti-microbial properties against cells of
Saccharomyces cerevisiae. Low concentrations of the oil (0.1%) inhibited the ...growth of
S. cerevisiae cells completely. The composition of the sample of palmarosa oil was determined as 65% geraniol and 20% geranyl acetate as confirmed by GC–FTIR. The effect of palmarosa oil in causing K
+ leakage from yeast cells was attributed mainly to geraniol. Some leakage of magnesium ions was also observed. Blocking potassium membrane channels with caesium ions before addition of palmarosa oil did not change the extent of K
+ ion leakage, which was equal to the total sequestered K
+ in the cells. Palmarosa oil led to changes in the composition of the yeast cell membrane, with more saturated and less unsaturated fatty acids in the membrane after exposure of
S. cerevisiae cells to the oil. Some of the palmarosa oil was lost by volatilization during incubation of the oil with the yeast cells. The actual concentration of the oil components affecting the yeast cells could not therefore be accurately determined.
Geraniol in palmarosa oil led to changes in composition of the yeast cell membrane, with leakage of K
+ and Mg
2+ ions from cells.
We have developed a method for the T4 DNA ligase-catalyzed DNA-templated polymerization of 5′-phosphorylated pentanucleotides containing peptide fragments. The polymerization proceeds ...sequence-specifically to generate DNA-scaffolded peptides in excellent yields. The method has been shown to tolerate peptides ranging from two to eight amino acids in length with a wide variety of functionality. We validated the capabilities of this system in a mock selection for the enrichment of a His-tagged DNA-scaffolded peptide phenotype from a library, which exhibited a 190-fold enrichment after one round of selection. This strategy demonstrates a promising new approach to allowing the generation and in vitro selection of high-affinity reagents based upon single-stranded DNA scaffolding of peptide fragments.
Numerous reports have identified therapeutic roles for plants and their extracts and constituents. The aim of this study was to assess the efficacies of three plant extracts for their potential ...antioxidant and anti-inflammatory activity in primary human skin fibroblasts.
Aqueous extracts and formulations of white tea, witch hazel and rose were subjected to assays to measure anti-collagenase, anti-elastase, trolox equivalent and catalase activities. Skin fibroblast cells were employed to determine the effect of each extract/formulation on IL-8 release induced by the addition of hydrogen peroxide. Microscopic examination along with Neutral Red viability testing was employed to ascertain the effects of hydrogen peroxide directly on cell viability.
Considerable anti-collagenase, anti-elastase, and antioxidant activities were measured for all extracts apart from the witch hazel distillate which showed no activity in the collagenase assay or in the trolox equivalence assay. All of the extracts and products tested elicited a significant decrease in the amount of IL-8 produced by fibroblast cells compared to the control (p < 0.05). None of the test samples exhibited catalase activity or had a significant effect on the spontaneous secretion of IL-8 in the control cells which was further corroborated with the microscopy results and the Neutral Red viability test.
These data show that the extracts and products tested have a protective effect on fibroblast cells against hydrogen peroxide induced damage. This approach provides a potential method to evaluate the claims made for plant extracts and the products in which these extracts are found.
Owing to their roles in tissue remodelling in health and disease, several studies have reported investigations on plant extracts as inhibitors of proteinases and as anti-oxidants.
The anti-ageing and ...anti-oxidant properties of 23 plant extracts (from 21 plant species) were assessed as anti-elastase and anti-collagenase activities and in selected anti-oxidant assays along with phenolic content.
Anti-elastase activities were observed for nine of the extracts with inhibitory activity in the following order: white tea (approximately 89%), cleavers (approximately 58%), burdock root (approximately 51%), bladderwrack (approximately 50%), anise and angelica (approximately 32%). Anti-collagenase activities were exhibited by sixteen plants of which the highest activity was seen in white tea (approximately 87%), green tea (approximately 47%), rose tincture (approximately 41%), and lavender (approximately 31%). Nine plant extracts had activities against both elastase (E) and collagenase (C) and were ranked in the order of white tea (E:89%, C:87%) > bladderwrack (E:50%, C:25%) > cleavers (E:58%, C:7%) > rose tincture (E:22%, C:41%) > green tea (E:10%: C:47%) > rose aqueous (E: 24%, C:26%) > angelica (E:32%, C:17%) > anise (E:32%, C:6%) > pomegranate (E:15%, C:11%).Total phenolic content varied between 0.05 and 0.26 mg gallic acid equivalents (GAE)/mL with the exception of white tea (0.77 mg GAE/mL). For anti-oxidant assessment, the Trolox equivalent anti-oxidant capacity (TEAC) assay revealed activity for all extracts. White tea had the highest activity equivalent to approximately 21 microM Trolox for a 6.25 microg aliquot. In addition, seven extracts exhibited activities = 10 microM Trolox with witch hazel (6.25 microg = 13 microM Trolox) and rose aqueous (6.25 microg = 10 microM Trolox) showing very high activities at low concentrations. A high activity for white tea was also found in the superoxide dismutase (SOD) assay in which it exhibited ~88% inhibition of reduction of nitroblue tetrazolium. High activities were also observed for green tea (86.41%), rose tincture (82.77%), witch hazel (82.05%) and rose aqueous (73.86%).
From a panel of twenty three plant extracts, some one dozen exhibit high or satisfactory anti-collagenase or anti-elastase activities, with nine having inhibitory activity against both enzymes. These included white tea which was found to have very high phenolic content, along with high TEAC and SOD activities.
Birth weight depends on the elaborate interaction between maternal and fetal genotypes, placental function, maternal nutrition and lifestyle and their effect on epigenetic regulators of gene ...activity. The maternal environment in which the fetus develops is a critical factor in determining birth weight. This review provides an overview of the effect of several genetic variants leading to intrauterine growth restriction and low birth weight. Irrespective of the exact cause of genetic variations of fetal genes, intrauterine growth restriction is most likely due to alteration in the growth hormone and insulin like growth factor axis with distinct changes in the growth factors and their interaction with corresponding receptors. Interactions also occur between the fetal genotype and the intrauterine environment, influencing expression certain genes required for fetal growth. Genomic imprinting is an important mechanism whereby the restraint of fetal growth could be determined through the maternal line. Furthermore, maternal cigarette smoking results in genetic variations in two specific genes, which interact synergistically, resulting in low birth weight. Confined placental mosaicism can also lead to clinically compelling intrauterine growth restriction or even intrauterine fetal death.
Single-agent chemotherapy is largely the treatment of choice for systemic therapy of metastatic melanoma, but survival rates are low, and novel adjuvant and systemic therapies are urgently required. ...Endoplasmic reticulum (ER) stress is a potential therapeutic target, and two relatively new drugs, fenretinide and bortezomib (Velcade), each acting via different cellular mechanisms, induce ER stress leading to apoptosis in melanoma cells. The aim of this study was to test the hypothesis that apoptosis of melanoma cells may be increased by combining clinically achievable concentrations of fenretinide and bortezomib.
Three human melanoma cell lines were used to assess changes in viability and the induction of apoptosis in response to fenretinide, bortezomib, or both drugs together. A s.c. xenograft model was used to test responses in vivo.
Fenretinide and bortezomib synergistically decreased viability and increased apoptosis in all three melanoma lines at clinically achievable concentrations. This was also reflected by increased expression of GADD153, a marker of ER stress-induced apoptosis. In vivo, fenretinide in combination with bortezomib gave a marked reduction in xenograft tumor volume and an increase in apoptosis compared with fenretinide or bortezomib alone. The cell cycle stage of tumor cells in vivo were similar to that predicted from the effects of each drug or the combination in vitro.
These results suggest that fenretinide and bortezomib, both of which are available in clinical formulation, warrant clinical evaluation as a combination therapy for metastatic melanoma.
PDF
