ObjectivesThe present study aimed at determining the antioxidant activity, total phenols and flavonoids and to evaluate the antiproliferative activity of ethanolic extract of Matricaria recutita L. (chamomile). The antioxidant activities were measured using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The total phenolic content was measured by the Folin–Ciocalteu assay. The flavonoid content was determined using the aluminum chloride method. The MTT assay was used to estimate the antiproliferative activities against human hepatoma (HepG2) cancer cell line. We assessed the mode of action of the extract as a cancer preventive agent and reported its ability to regulate tumor angiogenesis by down regulating in a dose dependent manner the expression of some proteins involved in the process.ResultsThe percentage inhibition of DPPH scavenging activity was dose-dependent ranging between (94.8% ± 0.03) at 1.50 mg/mL and (84.2% ± 0.86) at 0.15 mg/mL. It showed high polyphenols (21.4 ± 0.327 mg GAE/g) and high flavonoids content (157.9 ± 2.22 mg QE/g). Effect of extract was investigated against HepG2 cells. A dose-dependent reduction in cell viability was recorded in cells treated with the extract. The IC50 was ~ 300 µg/mL. It significantly inhibited the level of important prerequisite angiogenesis markers both in HepG2 cells and ex vivo.Electronic supplementary materialThe online version of this article (10.1186/s13104-018-3960-y) contains supplementary material, which is available to authorized users.

BackgroundHere, we determined in vitro antioxidant activity, total phenols and flavonoids and evaluated antiproliferative activity of three medicinal plant extracts: Trigonella foenum-graecum (Fenugreek), Cassia acutifolia (Senna) and Rhazya stricta (Harmal).MethodsThe leaves of the three medicinal plants were extracted with 70% ethanol. Antioxidant activities of the extracts were determined by using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Total flavonoid and phenolic contents were determined using colorimetric assays. MTT assay was used to estimate the antiproliferative activities of the extracts against human hepatoma (HepG2) cancer cell line. In addition, the effects of R. stricta extract on cell cycle, colony formation, and wound healing of HepG2 cells and tube formation of HUVEC cells were assessed.ResultsPercentage inhibition of DPPH scavenging activity were dose-dependent and ranged between (89.9% ± 0.51) and (28.6% ± 2.07). Phenolic contents ranged between (11.5 ± 0.013) and (9.7 ± 0.008) mg GAE/g while flavonoid content ranged between (20.8 ± 0.40) and (0.12 ± 0.0.01) mg QE/g. Antiproliferative results of the extracts were found to be consistent with their antioxidant activity. Among the extracts evaluated, that of R. stricta showed the best antioxidant, antiproliferative and antimetastatic activities at low concentration. It also inhibited the colony-formation capacity of HepG2 cells and exhibited antiangiogenic activity. Cell cycle analysis showed significant arrest of cells at G2/M phase 12 and 48 h after treatment and significant arrest at G1/S phase after 24 h of treatment. Consistent data were observed in western blot analysis of protein levels of Cdc2 and its cyclin partners.ConclusionsThese findings introduce R. stricta as a potentially useful anti-metastatic agent and a novel potential anti-tumour agent for hepatocellular carcinoma (HCC) treatment.Electronic supplementary materialThe online version of this article (10.1186/s12906-018-2285-7) contains supplementary material, which is available to authorized users.

Concentrations of nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), ozone (O 3 ), and ammonia (NH 3 ) were determined in the ambient air of Al-Ain city over a year using the passive sampling method associated with ion chromatographic and potentiometric detections. IVL samplers were used for collecting nitrogen and sulfur dioxides whereas Ogawa samplers were used for collecting ozone and ammonia. Five sites representing the industrial, traffic, commercial, residential, and background regions of the city were monitored in the course of this investigation. Year average concentrations of ≤59.26, 15.15, 17.03, and 11.88 μg/m 3 were obtained for NO 2 , SO 2 , O 3 , and NH 3 , respectively. These values are lower than the maxima recommended for ambient air quality standards by the local environmental agency and the world health organization. Results obtained were correlated with the three meteorological parameters: humidity, wind speed, and temperature recorded during the same period of time using the paired t test, probability p values, and correlation coefficients. Humidity and wind speed showed insignificant effects on NO 2 , SO 2 , O 3 , and NH 3 concentrations at 95% confidence level. Temperature showed insignificant effects on the concentrations of NO 2 and NH 3 while significant effects on SO 2 and O 3 were observed. Nonlinear correlations (R 2 ≤ 0.722) were obtained for the changes in measured concentrations with changes in the three meteorological parameters. Passive samplers were shown to be not only precise (RSD≤13.57) but also of low cost, low technical demand, and expediency in monitoring different locations.

The use of plants to improve dental health and to promote oral hygiene has been practiced for centuries and persists in several communities throughout the world. Salvadora persica (Miswak) has a wide geographic distribution. The ancient Arabs had the habit of using it to whiten and polish the teeth. Here, we determined in vitro antioxidant activity, total phenols and flavonoids and evaluated antiproliferative activity of the extract of S. persica (Miswak). The MTT assay was used to estimate the antiproliferative activities of the extract against human hepatoma (HepG2) cancer cell line. Inhibition percentage of DPPH scavenging activity was dose-dependent and ranged from (30.7% ± 0.62) to (5.89% ± 0.98). The phenolic content was (2.7 ± 0.11) mg GAE/g while the flavonoid content was (2.70 ± 0.45) mg QE/g. Antiproliferative results of the extracts were found to be consistent with their antioxidant activity. Our extract also exhibited clear antiangiogenic activity. These findings introduce S. persica as the useful and novel potential anti-tumor agent for hepatocellular carcinoma (HCC) treatment.

This research includes the design and synthesis of new derivatives for rhodanine azo compounds (4a–c) containing a naphthalene ring. Physiochemical properties of the synthesized compounds were determined by their melting points, FTIR, 1H-NMR, 13C-NMR, and elemental analysis spectroscopic techniques. The biological activities of the newly prepared azo rhodanine compounds were evaluated against some pathogenic bacteria using three different bacterial species including (Escherichia coli., Pseudomonas aeruginosa, Staphylococcus aureus) and compared with amoxicillin as a reference drug. The results showed that our compounds have moderate-to-good vital activity against the mentioned pathogenic bacteria. The selectivity and sensitivity of the newly prepared rhodanine azo compounds with transition metals Co2+, Cu2+, Zn2+, Ni2+, and Fe3+ were studied using UV–vis and fluorescence spectroscopy techniques. Among the synthesized azos, azo 4c showed affinity toward Fe3+ ions with an association constant of 4.63 × 108 M−1. Furthermore, this azo showed high sensitivity toward Fe3+ ions with detection limits of 5.14 µM. The molar ratio and Benesi–Hildebrand methods confirmed the formation of complexes between azo 4c and Fe3+ with 1:2 binding stoichiometry. Therefore, azo 4c showed excellent potential for developing efficient Fe3+ chemosensors.

We describe here the synthesis, antioxidant capacity, and biological activities on MAO, ChE, and selected GPCRs, of novel 1‐(2,5‐dimethoxybenzyl)‐4‐arylpiperazines 1–10, as well as known N‐(2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl))‐2‐(4‐arylpiperazin‐1‐yl) 11–20 and N‐(5‐nitrothiazol‐2‐yl)‐2‐(4‐arylpiperazin‐1‐yl) 21–29. Some of the new 4‐arylpiperazines were found to have low‐micromolar affinities for the proteins tested. The most potent MAO inhibitor identified was compound 2‐(4‐(3‐fluorophenyl)‐yl)‐N‐(5‐nitrothiazol‐2‐yl)(27), with an IC50 value of 4.14 ± 0.5 μM, whereas the most potent interaction with a GPCR was 1‐(2,5‐dimethoxybenzyl)‐4‐(4‐trifluoromethylphenyl) (5) for the 5‐HT6 serotonin receptor, with a Ki value of 0.7 μM. Interestingly, some of the compounds described here showed impressive antioxidant potential. Of mention, compounds 1, 6, 7, and 23 had trolox/equivalent ORAC values of 9.10, 8.80, 8.82, and 9.42, respectively, all of them being significantly higher than the TE determined for ferulic acid (3.74), a standard antioxidant. Among all molecules synthesized and tested, compound 23 can be regarded as an interesting low‐micromolar MAO−B/5‐HT6 dual inhibitor lead with potent antioxidant properties.

The vision of 6G communications is an improved performance of the data rate and latency limitations and permit ubiquitous connectivity. In addition, 6G communications will adopt a novel strategy. Terahertz (THz) waves will characterize 6G networks, due to 6G will integrate terrestrial wireless mobile communication, geostationary and medium and low orbit satellite communication and short distance direct communication technologies, as well as integrate communication, computing, and navigation. This study discusses the key challenges of THz waves, including path losses which is considered the main challenge; transceiver architectures and THz signal generators; environment of THz with network architecture and 3D communications; finally, Safety and health issues.

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