Nadia Taibi

Bio: Nadia Taibi is an academic researcher from University of Science and Technology Houari Boumediene. The author has contributed to research in topics: One-pot synthesis & Apoptosis. The author has an hindex of 4, co-authored 12 publications receiving 34 citations.

Effects of Spiro-bisheterocycles on Proliferation and Apoptosis in Human Breast Cancer Cell Lines.

Abstract: Breast cancer is the leading cause of cancer-related death in women worldwide and a critical public health concern. Here we investigated the anticancer potential and effects of low-molecular-weight bridgehead oxygen and nitrogen-containing spiro-bisheterocycles on proliferation and apoptosis of the human breast cancer cell lines MCF-7 and MDA-MB-231. The compounds feature a hydantoin moiety attached to either diazole, isoxazole, diazepine, oxazepine or benzodiazepine via the privileged tetrahedral spiro-linkage. Treatment with compounds spiro [hydantoin-isoxazole] and spiro [hydantoin-oxazepine] resulted in a dose-dependent decrease of cell proliferation and induction of apoptosis in both breast cancer cell lines, whereas spiro [hydantoin-diazepine] was only active against MDA-MB 231. Quantitative reverse transcription polymerase chain reaction analysis showed up-regulation of murine double minute 2 (MDM2), strictly p53-dependent, and detected an increase in expression of pro-apoptotic caspase 3 and BCL2-associated X (BAX) genes in both breast cancer cell lines expressing wild-type and mutant p53. In summary, the results suggest that our compounds promote apoptosis of breast cancer cell lines via p53-dependent and -independent pathways.

Physicochemical characterization and determination of chloramphenicol residues and heavy metals in Algerian honeys

Abstract: The concentration of certain heavy metals in various foods (fruits, cereals, legumes, and bee products) produced in industrial and urban cities is increasing each year following industrial development. Quality of honey and its contamination by different polluting agents are related essentially to its production environment, or it can arise from beekeeping practices. In the present study, the determination of physicochemical properties: moisture, pH, total acidity, electric conductivity, hydroxymethylfurfural (HMF), sugars, and chloramphenicol (CAP) residues; the metal content by determination of two toxic metals levels: lead (Pb) and cadmium (Cd); and other trace elements: magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and nickel (Ni) in 23 different honey samples collected from North regions of Algeria were investigated. The physicochemical properties and the metal contents were found within the ranges established by the international standards. For the antibiotic residues, only four honey samples are contaminated by CAP. Metals were found in non-significant values and are in safety baseline levels for human consumption except Mg which exceed the limits. These results suggested that honey could be used as an indicator to detect contaminating agents from the environment since bees are excellent sentinels for assessing environmental contamination because of their physiological and biological characteristics.

Actions of Bisnucleophiles on (E)-3-[3-(2-Hydroxyaryl)-3-oxoprop-1-en-1-yl]chromones: Versatile Transformations into Oxygen- and Nitrogen-Containing Heterocycles

Abstract: The transformations of ( E )-3-[3-(2-hydroxyaryl)-3-oxoprop-1-en-1-yl]chromones in the presence of methylhydrazine and aromatic bisnucleophiles are described. The reactions generally lead to chromone ring transformation via pyrone ring-opening and heterocyclization to give novel diazoles and ( Z )-3-aminomethylenechromanones, respectively. Piperazine catalyzes chromanone ring closure of the starting substrate to afford chromone–chromanone dyads.

Anti-proliferative, Cytotoxic and NF-ĸB Inhibitory Properties of Spiro(Lactone-Cyclohexanone) Compounds in Human Leukemia.

Abstract: Background/aim NF-ĸB affects most aspects of cellular physiology. Deregulation of NF-ĸB signaling is associated with inflammatory diseases and cancer. In this study, we evaluated the cytotoxic and NF-ĸB inhibition potential of new spiro(lactone-cyclohexanone) compounds in two different human leukemia cell lines (U937 and K562). Materials and methods The anti-proliferative effects of the spiro(lactone-cyclohexanone) compounds on human K562 and U937 cell lines was evaluated by trypan blue staining, as well as their involvement in NF-kB regulation were analyzed by luciferase reporter gene assay, Caspase-3/7 activities were evaluated to analyze apoptosis induction. Results Both spiro(coumarin-cyclohexanone) 4 and spiro(6- methyllactone-cyclohexanone) 9 down-regulated cancer cell viability and proliferation. Compound 4 inhibited TNF-α-induced NF-ĸB activation in a dose-dependent manner and induced caspase-dependent apoptosis in both leukemia cell lines. Conclusion Results show that compound 4 and compound 9 have potential as anti-cancer agents. In addition, compound 4 exerted NF-kB inhibition activity in leukemia cancer cells.

AMPK Function in Mammalian Spermatozoa

Abstract: AMP-activated protein kinase AMPK regulates cellular energy by controlling metabolism through the inhibition of anabolic pathways and the simultaneous stimulation of catabolic pathways. Given its central regulator role in cell metabolism, AMPK activity and its regulation have been the focus of relevant investigations, although only a few studies have focused on the AMPK function in the control of spermatozoa’s ability to fertilize. This review summarizes the known cellular roles of AMPK that have been identified in mammalian spermatozoa. The involvement of AMPK activity is described in terms of the main physiological functions of mature spermatozoa, particularly in the regulation of suitable sperm motility adapted to the fluctuating extracellular medium, maintenance of the integrity of sperm membranes, and the mitochondrial membrane potential. In addition, the intracellular signaling pathways leading to AMPK activation in mammalian spermatozoa are reviewed. We also discuss the role of AMPK in assisted reproduction techniques, particularly during semen cryopreservation and preservation (at 17 °C). Finally, we reinforce the idea of AMPK as a key signaling kinase in spermatozoa that acts as an essential linker/bridge between metabolism energy and sperm’s ability to fertilize.

Synthesis of Chromone-Related Pyrazole Compounds.

Abstract: Chromones, six-membered oxygen heterocycles, and pyrazoles, five-membered two-adjacent-nitrogen-containing heterocycles, represent two important classes of biologically active compounds. Certain derivatives of these scaffolds play an important role in medicinal chemistry and have been extensively used as versatile building blocks in organic synthesis. In this context, we will discuss the most relevant advances on the chemistry that involves both chromone and pyrazole rings. The methods reviewed include the synthesis of chromone-pyrazole dyads, synthesis of chromone-pyrazole-fused compounds, and chromones as starting materials in the synthesis of 3(5)-(2-hydroxyaryl)pyrazoles, among others. This review will cover the literature on the chromone and pyrazole dual chemistry and their outcomes in the 21st century.

Spirocyclic derivatives as antioxidants: a review

Abstract: In recent years, spiro compounds have attracted significant interest in medicinal chemistry due to their numerous biological activities attributed primarily to their versatility and structural similarity to important pharmacophore centers. Currently, the development of drugs with potential antioxidant activities is of great importance since numerous investigations have shown that oxidative stress is involved in the development and progression of numerous diseases such as cancer, senile cataracts, kidney failure, diabetes, high blood pressure, cirrhosis, and neurodegenerative diseases, among others. This article provides an overview of the synthesis and various antioxidant activities found in naturally occurring and synthetic spiro compounds. Among the antioxidant activities reviewed are DPPH, ABTS, FRAP, anti-LPO, superoxide, xanthine oxidase, peroxide, hydroxyl, and nitric oxide tests, among others. Molecules that presented best results for these tests were spiro compounds G14, C12, D41, C18, C15, D5, D11, E1, and C14. In general, most active compounds are characterized for having at least one oxygen atom; an important number of them (around 35%) are phenolic compounds, and in molecules where this functional group was absent, aryl ethers and nitrogen-containing functional groups such as amine and amides could be found. Recent advances in the antioxidant activity profiles of spiro compounds have shown that they have a significant position in discovering drugs with potential antioxidant activities.