Soleiman Hisaindee

Mitotic Arrest and Apoptosis in Breast Cancer Cells Induced by Origanum majorana Extract: Upregulation of TNF-α and Downregulation of Survivin and Mutant p53

Background In the present study, we investigated the effect of Origanum majorana ethanolic extract on the survival of the highly proliferative and invasive triple-negative p53 mutant breast cancer cell line MDA-MB-231. Results We found that O. majorana extract (OME) was able to inhibit the viability of the MDA-MB-231 cells in a time- and concentration-dependent manner. The effect of OME on cellular viability was further confirmed by the inhibition of colony growth. We showed, depending on the concentration used, that OME elicited different effects on the MDA-MB 231 cells. Concentrations of 150 and 300 µg/mL induced an accumulation of apoptotic–resistant population of cells arrested in mitotis and overexpressing the cyclin-dependent kinase inhibitor, p21 and the inhibitor of apoptosis, survivin. On the other hand, higher concentrations of OME (450 and 600 µg/mL) triggered a massive apoptosis through the extrinsic pathway, including the activation of tumor necrosis factor-α (TNF-α), caspase 8, caspase 3, and cleavage of PARP, downregulation of survivin as well as depletion of the mutant p53 in MDA-MB-231 cells. Furthermore, OME induced an upregulation of γ-H2AX, a marker of double strand DNA breaks and an overall histone H3 and H4 hyperacetylation. Conclusion Our findings provide strong evidence that O. majorana may be a promising chemopreventive and therapeutic candidate against cancer especially for highly invasive triple negative p53 mutant breast cancer; thus validating its complementary and alternative medicinal use.

Rhus coriaria induces senescence and autophagic cell death in breast cancer cells through a mechanism involving p38 and ERK1/2 activation

Here, we investigated the anticancer effect of Rhus coriaria on three breast cancer cell lines. We demonstrated that Rhus coriaria ethanolic extract (RCE) inhibits the proliferation of these cell lines in a time- and concentration-dependent manner. RCE induced senescence and cell cycle arrest at G1 phase. These changes were concomitant with upregulation of p21, downregulation of cyclin D1, p27, PCNA, c-myc, phospho-RB and expression of senescence-associated β-galactosidase activity. No proliferative recovery was detected after RCE removal. Annexin V staining and PARP cleavage analysis revealed a minimal induction of apoptosis in MDA-MB-231 cells. Electron microscopy revealed the presence of autophagic vacuoles in RCE-treated cells. Interestingly, blocking autophagy by 3-methyladenine (3-MA) or chloroquine (CQ) reduced RCE-induced cell death and senescence. RCE was also found to activate p38 and ERK1/2 signaling pathways which coincided with induction of autophagy. Furthermore, we found that while both autophagy inhibitors abolished p38 phosphorylation, only CQ led to significant decrease in pERK1/2. Finally, RCE induced DNA damage and reduced mutant p53, two events that preceded autophagy. Our findings provide strong evidence that R. coriaria possesses strong anti-breast cancer activity through induction of senescence and autophagic cell death, making it a promising alternative or adjunct therapeutic candidate against breast cancer.

Spectroscopic studies of keto–enol tautomeric equilibrium of azo dyes

Azo dyes account for 60–70% of all dyes known to date. Understanding the factors that affect the direction of keto–enol tautomerism in azo dyes through spectral measurements is crucial to their potential applications. This review encompasses the most important spectroscopic studies of different azo dyes categorized by their structures within the last few years (2010–2014). It is concluded that the stability of the keto and enol forms largely arises from the ability to establish intra-molecular and inter-molecular hydrogen bonding, respectively. There are many factors that affect the keto or enol form, for example, polar solvent, high temperature, neutral pH and electron withdrawing substituents favor the keto form through intramolecular hydrogen bonding, whereas, nonpolar solvent, low temperature, high pH and electron donating groups favor the enol form through intermolecular hydrogen bonding. Encapsulation inside nanocaged microheterogenous systems creates a rigid environment that stabilizes the enol form mostly, while in the solid state, most of the tautomeric equilibrium lies in favor of the keto form. Understanding of keto–enol tautomerism in azo dyes helps to probe solvation dynamics, to tune the pKa values in chemical sensing, and to explain proton transfer in the excited state.

Liquid chromatography tandem mass spectrometry analysis of photodegradation of a diazo compound: A mechanistic study

The photolytic degradation of the diazo dye, Amido Black, using UV/H(2)O(2) has been carried out experimentally and parameters for most efficient dye degradation have been determined. The degradation of the dye was followed by UV-Vis spectroscopy, HPLC, and LC-MS and is proposed to be initiated by ()OH radicals formed by the photolysis of H(2)O(2). A detailed study was also carried out using LC-MS and LC-MS/MS to determine the degradation pathway of the dye as well as to identify some of the intermediate products formed. Our results suggest that Amido Black degradation occurs preferentially by ()OH radical attack at the more electron rich diazo functionality of the molecule. Furthermore, evidence is presented that subsequent steps in this diazo dye degradation pathway include radical denitration, radical desulfonation and radical diazotization. This report is one of the very few studies that have proposed possible mechanistic pathways for the degradation pathways of a diazo compound.

Genotoxicity of structurally related copper and zinc containing Schiff base complexes.

Abstract The utilization of Schiff bases in the industrial and pharmaceutical fields has led to an increase in their syntheses and evaluation of their biological activities. In this study, we described the synthesis and genotoxicity of two Schiff bases that share common platform in their construction, namely, naphthalene, and are complexed to either Cu(II) or Zn(II). The genotoxicity of these complexes was evaluated in cultured lymphocytes using sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs), and in rats using the urine 8-OH-2-deoxyguanosine (8-OH-dG) assay. The results showed that the examined complexes are genotoxic, but with different degrees. The order of genotoxicity of the complexes at 10 µg/mL was: Cu(L3)(NCS)(H2O) > Zn(L3)(NCS)(H2O) > Cu(L2)(NCS) > Zn(L2)(NCS), where L2 and L3 are the conjugate bases of N-(8-quinolyl)napthaldimine and N-(anilinyl)napthaldimine, respectively. However, at the 1-µg/mL concentration, only the Cu(L3)(NCS)(H2O) complex induced significant CAs, whereas at the 0.1-µg/mL concentration, only Cu(L3)(NCS)(H2O) and Zn(L2)(NCS) complexes induced significant SCEs, compared to controls. In the urine 8-OH-dG assay, all complexes at 10 mg/100 g body weight (b.w.) were found to cause DNA damage with the following order: Cu(L3)(NCS)(H2O) > Zn(L2)(NCS) > Zn(L3)(NCS)(H2O) > Cu(L2)(NCS), whereas no significant DNA damage was observed in animals exposed to 1 and 0.1 mg/100 g b.w. (p > 0.05). In conclusion, the two examined Schiff base complexes are found to induce DNA damage, but with different degrees.

Enzymatic pre-treatment of microalgae cells for enhanced extraction of proteins

Crude proteins and pigments were extracted from different microalgae strains, both marine and freshwater. The effectiveness of enzymatic pre‐treatment prior to protein extraction was evaluated and compared to conventional techniques, including ultrasonication and high‐pressure water extraction. Enzymatic pre‐treatment was chosen as it could be carried out at mild shear conditions and does not subject the proteins to high temperatures, as with the ultrasonication approach. Using enzymatic pre‐treatment, the extracted proteins yields of all tested microalgae strains were approximately 0.7 mg per mg of dry cell weight. These values were comparable to those achieved using a commercial lytic kit. Ultrasonication was not very effective for proteins extraction from Chlorella sp., and the extracted proteins yields did not exceed 0.4 mg per mg of dry cell weight. For other strains, similar yields were achieved by both treatment methods. The time‐course effect of enzymatic incubation on the proteins extraction efficiency was more evident using laccase compared to lysozyme, which suggested that the former enzyme has a slower rate of cell disruption. The crude extracted proteins were fractionated using an ion exchange resin and were analyzed by the electrophoresis technique. They were further tested for their antioxidant activity, the highest of which was about 60% from Nannochloropsis sp. The total phenolic contents in the selected strains were also determined, with Chlorella sp. showing the highest content reaching 17 mg/g. Lysozyme was also found to enhance the extraction of pigments, with Chlorella sp. showing the highest pigments contents of 16.02, 4.59 and 5.22 mg/g of chlorophyll a, chlorophyll b and total carotenoids, respectively.

Clinical diagnostic tools for vitamin D assessment

Vitamin D deficiency has been implicated in a plethora of diseases including rheumatoid arthritis, Parkinsons disease, Alzheimers disease, and osteoporosis. Deficiency of this vitamin is a global epidemic affecting both developing and developed nations. Within a clinical context, the qualitative and quantitative analysis of vitamin D is therefore vital. The main metabolic markers for assessing vitamin D status in humans are the hydroxylated forms of vitamin D, 25OHD3 and 25OHD2 on account of their long half-lives within the body and excellent stability. An adequate level for healthy individuals of these hydroxylated forms is estimated to be around 20-40ng/ml of blood. There are three main analytical techniques for determining the levels of 25OHD3 and 25OHD2. The first technique is immunoassay-based and can be performed in a rapid, high throughput, automated manner, allowing as many as 240 tests per hour with the duration of each assay as little as 18min. Furthermore, it offers excellent sensitivity with a detection range of 3.4-156ng/ml. A major downside of immunoassays is that they are unable to distinguish between the various forms of vitamin D. While HPLC is a highthroughput low cost instrument it is not a very sensitive technique and cannot quantify the down stream metabolites of vitamin D. The third technique, namely liquid chromatography-mass spectrometry (LC-MS/), provides excellent sensitivity with a wide dynamic range from 0.068pg/ml to 100ng/ml. Additionally, it offers a high level of separation and permits identification of vitamin D-related metabolites. However, a huge limitation with LC/MS/MS is their poor throughput for sample analyses. As yet, there is no analytical technique which combines the fine detection capabilities of LC/MS/MS and the rapid, automated format of immunoassay, for vitamin D analyses. Future attention therefore needs to be given to this area if the current clinical diagnostic tools for vitamin D analysis are to be further improved.

Development of a therapeutic model of precancerous liver using crocin-coated magnetite nanoparticles

Despite considerable advances in understanding hepatocellular carcinoma, it is one of the common and deadliest cancers worldwide. Hence, increasing efforts are needed for early diagnosis and effective treatments. Saffron has been recently found to inhibit growth of liver cancer in rats. The aim of this study was to develop an effective method for treatment of liver cancer using magnetite nanoparticles (MNPs) coated with crocin, the main active component of saffron. MNPs were prepared and initially coated with dextran and a cross-linker to enhance conjugation of crocin using a modified coprecipitation method. Cultured HepG2 cells and diethylnitrosamine-injected mice were treated with corcin-coated MNPs and analyzed using cell proliferation assay and immunohistochemical analysis, respectively. Treatment of HepG2 cells with crocin-coated MNPs led to a significant inhibition of their growth as compared to control or those treated with free crocin or uncoated MNPs. Histological examinations of the livers of diethylnitrosamine-injected mice revealed several precancerous changes: multiple proliferative hepatic foci, hyper- or dysplastic transformations of bile ducts/ductules, and nuclear atypia associated with polyploidy, karyomegaly, and vacuolation. Immunohistochemistry using antibodies specific for cell proliferation (Ki-67) and apoptosis (M30-CytoDEATH and Bcl-2) revealed their upregulation during development of precancerous lesions. Using antibodies specific for inflammation (cyclooxygenase-2), oxidative stress (glutathione) and angiogenesis (vascular endothelial growth factor) indicated the involvement of multiple signaling pathways in the development of precancerous lesions. Treatment with crocin-coated MNPs was associated with regression of precancerous lesions, significant upregulation of apoptotic cells and downregulation of Bcl-2 labeling and markers of cell proliferation, inflammation, oxidative stress and angiogenesis. In conclusion, crocin-coated MNPs are more effective than free corcin for treatment of liver precancerous lesions in mice. These findings will help to develop new modalities for early detection and treatment of liver precancerous lesions.

Synthesis, characterization, anti-bacterial, anti-fungal and nematicidal activities of 2-amino-3-cyanochromenes

Soil-borne plant pathogens such as nematodes, fungi and some bacteria not only affect the plant cultures but also economy and environmental implications. As a result of these pathogens attacks, the yield and quality of crops is affected. Therefore, synthesis of new compounds to control these pathogens is very important and need of time. Chromenes are considered important group of heterocyclic compounds and exhibited significant biological activities. 2-amino-3-cyano chromenes are considered important medicinal scaffolds among the chromenes. We describe three component microwave assisted synthesis of 2-amino-3-cyano chromenes. The versatility of the reaction was examined by varying the aldehydes in the reaction mixture which lead to the synthesis of series of 2-amino-3-cyanochromenes (1-9). The structural elucidations of the compounds were studied by 1H NMR, 13C NMR, HRMS and FTIR spectrometer and results were well correlated. The synthesized compounds were evaluated for their anti-bacterial, anti-fungal and nematicidal activities. Among the synthesized compounds, compound 6 showed good anti-bacterial activity while compound 9 exhibited high anti-fungal activity. In case of nematicidal activity, compound 8 indicated high activity as compare with other compounds followed by compound 9. Results indicate that these synthesized compounds could be used as effective control for soil-borne plant pathogens such as nematodes, fungi and bacteria and can help to improve the plant production.

Comparative Degradation of a Thiazole Pollutant by an Advanced Oxidation Process and an Enzymatic Approach

Organic pollutants, especially those found in water bodies, pose a direct threat to various aquatic organisms as well as humans. A variety of different remediation approaches, including chemical and biological methods, have been developed for the degradation of various organic pollutants. However, comparative mechanistic studies of pollutant degradation by these different systems are almost non-existent. In this study, the degradation of a model thiazole pollutant, thioflavin T (ThT), was carried out in the presence of either an advanced oxidation process (ultraviolet (UV) + H2O2) or a chloroperoxidase enzyme system (CPO + H2O2). The degradation was followed both spectrophotometrically and using liquid chromatography-mass spectroscopy (LC-MS), and the products formed were identified using tandem liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS). The results show that the two remediation approaches produced different sets of intermediates, with only one common species (a demethylated form of ThT). This suggests that different degradation schemes were operating in the two systems. Interestingly, one of the major intermediates produced by the CPO + H2O2 system was a chlorinated form of thioflavin. Phytotoxicity studies showed that the CPO + H2O2-treated ThT solution was significantly (p < 0.05) less toxic than the UV + H2O2-treated ThT solution. This is the first time that a comparative mechanistic study showing in detail the intermediates generated in chemical and biological remediation methods has been presented. Furthermore, the results show that different remediation systems have very different degradation schemes and result in products having different toxicities.