Evaluation of the synergistic antimicrobial effect of folk medicinal plants with clindamycin against methicillin-resistant Staphylococcus aureus strains

Antibiotic resistance has become a major worldwide priority, and identifying natural antimicrobial compounds may help overcome this problem. In this study, ethanolic extracts of 12 plants commonly used in traditional medicine were tested against two strains of methicillin-resistant Staphylococcus aureus (ATCC 33591 and ATCC 43300) in terms of minimum inhibitory concentrations (MICs). Furthermore, the effect of combining plant extracts with clindamycin antibiotic was also investigated using the checkerboard method. Among the tested plants, Camellia sinensis, Thymus vulgaris, Rosmarinus officinalis and Salvia officinalis exhibited potent inhibitory activity against both strains with MICs ranges (125-500 µg ml^-1 ). Synergistic activity was confirmed for the four plants combined with clindamycin with fractional inhibitory concentration index <0·5. However, no antagonistic activity was found for these combinations. Our findings suggest that using an antibiotics-plants combination might be a successful technique to reduce antibiotic consumption, which would overcome the antibiotics resistance or delay its onset.

Neurocognitive dysfunction in children with β thalassemia major: psychometric, neurophysiologic and radiologic evaluation

OBJECTIVE

To evaluate the impact of iron chelating drugs and serum ferritin on the neurocognitive functions of patients with β thalassemia major (β-TM), using psychometric, neurophysiologic and radiologic tests.

METHODS

Eighty children with β-TM were enrolled into the study and were compared to 40 healthy controls. All participants were evaluated by measuring serum ferritin, neurocognitive assessment by Benton Visual Retention Test, Wechsler Intelligence Scale for Children, Wisconsin Card Sort Test, P300 and magnetic resonance spectroscopy (MRS).

RESULTS

WISC in our study showed that 40% of cases were borderline mental function as regards total IQ. Neurophysiologic tests were significantly impaired in patients compared to control group, with significant impairment in those receiving desferrioxamine (DFO). P300 amplitude was significantly lower in cases compared to controls (2.24 and 4.66 uv, respectively), recording the shortest amplitude in patients receiving DFO. Altered metabolic markers in the brain were detected by MRS in the form of reduced N-acetylaspartate to creatine ratio in 78.3% of our cases. There were significant correlations between psychometric tests and both neurophysiologic (P300) and radiologic (MRS) tests.

CONCLUSION

β-TM is associated with neurocognitive impairment that can be assessed by psychometric, neurophysiologic and radiologic tests. The role of hemosiderosis and iron chelation therapy on cognitive functioning still need more research.

ABBREVIATIONS

β-TM: beta thalassemia major; DFO: Dysferal; DFP: Deferiprone; DFX: Deferasirox; WISC: Wechsler Intelligence Scale for Children; VIQ: verbal IQ; PIQ: performance IQ; TIQ: total IQ; BVRT: Benton Visual Retention Test; WCST: Wisconsin Card Sort Test; MRS: Magnetic resonant spectroscopy; NAA/Cr ratio: N-acetylaspartate to creatine ratio.

Preparation, characterization and antiproliferative activity of thymoquinone-beta-cyclodextrin self assembling nanoparticles

Thymoquinone (TQ) was complexed with beta-cyclodextrin (CD) to form nanosized aggregates. Various TQ:CD ratios were tested and it was found that the ratio of (1:0.25) TQ:CD formed distinguishable nanoparticles with minimum toxicity towards normal cells. These nanoparticles had an average size of 445 +/- 100 nm with a charge 21.8 mV using Zeta-sizer. Particle size measurement using scanning electron microscopy (SEM) showed an average size of 400 nm and it also revealed the presence of smaller structures, with an average size of 50 nm. The in vitro antiproliferative activity on MCF7 cells was determined using MTT assay and an IC50 of 4.70 +/- 0.60 microM for TQ-CD nanoparticles in comparison to 24.09 +/- 2.35 microM of free TQ solution after 72 h of incubation. Simultaneously, TQ-CD nanoparticles showed lesser toxicity than TQ solution using human periodontal fibroblasts as a model for normal cells. It could be concluded from the results that TQ loaded cyclodextrin nanoparticles might serve as a potential nanocarrier to improve TQ solubility as well as its antiproliferative activity with little toxicity to normal tissues.

A comparative immunohistochemical study of MART-1 expression in Spitz nevi, ordinary melanocytic nevi, and malignant melanomas

BACKGROUND

The histopathologic differential diagnosis of Spitz nevus (SN) from malignant melanoma (MM) may be difficult.

OBJECTIVE

We attempted to elucidate the pattern of expression of a newly recognized melanocyte-specific melanosomal protein MART-1 in routinely processed specimens of SNs, MMs, and ordinary melanocytic nevi (MNs) and to see whether it can help to differentiate between them.

METHODS

Twenty SN, 22 MM, and 27 ordinary MN were immunostained with anti-MART-1 monoclonal antibody (clone A103).

RESULTS

All SNs, MNs, and MMs demonstrated cytoplasmic staining for MART-1 in some of their tumor cells, of which 17 of 20 (85%) and 24 of 27 (89%) of SN and MN, respectively, demonstrated positive stainings in more than half of their tumor cells, as compared with only 10 of 22 (45%) of the MM (P <.05). The majority of lesions in all 3 types of tumors showed a homogeneous mode of staining, although MM tended to show a more heterogeneous pattern. A consistent pattern of stratification of staining with progressive descent into the dermis was not demonstrated in these tumors.

CONCLUSION

MART-1 does not differentiate between SN, MM, and ordinary MN in a consistent pattern, but it may be used as a marker for these tumors.

Molecular and cellular analysis of basement membrane invasion by human breast cancer cells in Matrigel-based in vitro assays

In vitro analyses of basement membrane invasiveness employing Matrigel (a murine tumor extract rich in basement membrane components) have been performed on human breast cancer model systems. Constitutive invasiveness of different human breast cancer (HBC) cell lines has been examined as well as regulation by steroid hormones, growth factors, and oncogenes. Carcinoma cells exhibiting a mesenchymal-like phenotype (vimentin expression, lack of cell border associated uvomorulin) show dramatically increased motility, invasiveness, and metastatic potential in nude mice. These findings support the hypothesis that epithelial to mesenchymal transition (EMT)-like events may be instrumental in the metastatic progression of human breast cancer. The MCF-7 subline MCF-7ADR appears to have undergone such a transition. The importance of such a transition may be reflected in the emergence of vimentin expression as an indicator of poor prognosis in HBC. Matrix degradation and laminin recognition are highlighted as potential targets for antimetastatic therapy, and analyses of laminin attachment and the matrix metalloproteinase (MMP) family in HBC cell lines are summarized. Matrigel-based assays have proved useful in the study of the molecular mechanisms of basement membrane invasiveness, their regulation in HBC cells, and their potential as targets for antimetastatic therapy.