Volume 77, Issue 3-4

During our exploring the anticancer activity of some medicinal plants and their major metabolites, the aerial parts of the Egyptian Matricaria chamomilla (flowers and stems) were studied. GC–MS analysis of the organic soluble extracts of the flowers and stems fractions revealed the presence of 43 and 45 compounds, respectively. Individual chromatographic purification of the flowers and stems’ extracts afforded three major compounds. Structures of these compounds were identified by 1D- and 2D-NMR and HRESI-MS spectroscopic data as bisabolol oxide A ( 1 ) and ( E )-tonghaosu ( 2 ) (as mixture of ratio 2:1) from the flowers extract, meanwhile apigenin-7- β - d -glucoside (3) from the stems fraction. Biologically, the chamomile extracts announced significant antiproliferative activities exceeded in potency by ∼1.5 fold in case of the stem, recording GI 50 13.16 and 17.04 μg/mL against Caco-2 and MCF-7, respectively. Both fractions were approximately equipotent against the migration of the same cell type down to 10 μg/mL together, compounds 1 , 2 but not 3 , showed considerable growth inhibition of the same cells at GI 50 13.36 and 11.83 μg/mL, respectively. Interestingly, they were able to suppress Caco-2 colon cancer cells migration at 5.8 μg/mL and potently inactivate the VEGFR2 angiogenic enzyme (1.5-fold relative to sorafenib. The obtained compounds and corresponding chamomile extracts were evaluated against Adeno-7 virus, revealing that both chamomiles’ extracts (flowers and stems) and their corresponding obtained compounds ( 1–3 ) were potent in their depletion to the Adeno 7 infectivity titer, however, the flower extract and compounds 1–2 were more effective than those of the stem extract and its end-product ( 3 ).

Rosemary officinalis L., Pelargonium graveolens L., and Mentha piperita L., essential oils are used by complementary medicine specialists simultaneously with traditional antibiotics for treatment purposes. The chemical composition of essential oils was analyzed by the gas chromatography-mass spectrometry method. In vitro antibacterial and antibiofilm activities of the essential oils were tested against extreme drug-resistant (XDR) colistin-resistant and colistin susceptible Acinetobacter baumannii clinical strains. The synergistic activities between essential oils and colistin antibiotics were investigated by the checkerboard method. The highest antibacterial effect was detected in mint essential oil (2.5–5 μl/ml), followed by pelargonium essential oil (5–20 μl/ml) and rosemary essential oil (5–20 μl/ml). The combination of rosemary essential oil or pelargonium essential oil with colistin showed strong synergistic activity in most of the bacterial strains tested (fractional inhibitory concentration index ≤ 0.5; synergy). As a result of the combination of mint essential oil and colistin, an indifferent effect was observed in only two bacterial strains, and other strains could not be evaluated. No antagonistic effects were observed in any of the tested essential oils. As a result of the effectiveness of the combination, the minimum inhibitory concentration (MIC) values of colistin in XDR- A. baumannii clinical isolates decreased 2–32 fold. Additionally, the sub-MIC concentration of essential oils exhibited an inhibitory effect (48–90%) against the biofilm layer of tested A. baumannii strains.

This study aims to investigate the chemical composition, antioxidant, and antimicrobial activity of two essential oils (EOs) from Algerian propolis. The volatile constituents were analyzed by gas chromatography-mass spectrometry. Fifty components were identified from the oils. The major components were found to be: cedrol (17.0%), β -eudesmol (7.7%), and α -eudesmol (6.7%) in EO of propolis from Oum El Bouaghi (EOPO) whilst α -pinene (56.1%), cis -verbenol (6.0%), and cyclohexene,3-acetoxy-4-(1-hydroxy-1-methylethyl)-1-methyl (4.4%) in EO of propolis from Batna (EOPB). The antioxidant properties of EOPO and EOPB were determined using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS•+) and cupric reducing antioxidant capacity (CUPRAC assays), respectively. Both EOs had more cupric ion reducing ability than scavenging ABTS•+ radicals. The antimicrobial potential of the two EOs against eight pathogens was assayed by the agar diffusion method and the mode of action was determined by microdilution assay. The results revealed that EOPB was bactericidal for all tested pathogenic bacteria and fungicidal for Candida albicans ATCC 10231, whereas, EOPO showed bacteriostatic effect against Escherichia coli O157:H7 and Pseudomonas aeruginosa ATCC27853 and fungistatic effect against C. albicans ATCC 10231. Thus, the obtained results suggest the important use of propolis EOs as preservative agents.

The protein stability of the initiation factors Orc2, Orc3, Orc4, and Cdc6 was analyzed after UV light exposure in two human cell lines. In the cell line with higher repair capacity, HEK 293, no changes in the cell cycle distribution or in the protein levels of the investigated factors were detected. In HeLa cells that are characterized by lower repair capacity, UV irradiation caused a reduction of the levels of Cdc6, Orc2 and Orc3, but not of Orc4 or triggered apoptosis. The appearance of the truncated 49 kDa form of Cdc6 suggested the involvement of the caspase pathway in the degradation of the proteins. Reduced protein levels of Cdc6 were detected in UV damaged HeLa cells in which the apoptotic process was blocked with the caspase inhibitor Z-VAD-fmk, indicating that the degradation of Cdc6 is mediated by the proteasome pathway instead. In the presence of caffeine, an inhibitor of the cell cycle checkpoint kinases, Cdc6 was stabilized, demonstrating that its degradation is controlled by the DNA damage cell cycle checkpoint. We conclude that in response to DNA damage, the activation of origins of replication can be prevented by the degradation of Cdc6, most likely through the proteasome pathway.

The antiplasmodium assay-guided investigation of the roots, stem bark, and leaves of Persea americana Mill. led to the isolation of a new fatty alcohol, perseatriol ( 1 ), along with six known compounds ( 2–7 ). Their structures were elucidated based on the analysis of their NMR and MS data. All crude extracts and fractions exhibited good antiplasmodial activity on Plasmoduim falciparum 3D7 with IC 50 values ranging from 0.76 to 10.5 μg/mL; they also displayed cytotoxicity against HeLa cells with low selectivity indexes (SIs). A preliminary Plasmodium lactate dehydrogenase (pLDH) assay was also performed on the isolated compounds. 9,9′-Di- O -feruloyl-5,5′-dimethoxysecoisolariciresinol ( 4 ) turned out to be non-toxic and displayed the best activities on P. falciparum with an IC 50 value of 0.05 μM, comparable to the reference drug chloroquine with an IC 50 value of 0.03 μM. Furthermore, besides compound 4 , this work reports the first isolation of lutein ( 2 ) and scopoletin ( 3 ) from P. americana . The crude extracts of roots, stem bark, and leaves of P. americana , their fractions and compounds completely suppressed the growth of P. falciparum . The observed activity supports the use of P. americana in folk medicine for the treatment of malaria.

In this study, total phenolic, flavonoid and protein contents, antiradical capacities, antibacterial and cytotoxic properties of five different Salvia species ( Salvia macrochlamys Boiss., Salvia kronenburgii Rech.f., Salvia euphratica Montbret. ex Aucher var. euphratica , Salvia huberi Hedge and Salvia kurdica Benth) were investigated. The total phenolic content of the species was in the range of 59.6 ± 20 to 150.1 ± 1.1 mg/g, total flavonoid content in the range of 20.4 ± 2.2 to 38.9 ± 4.1 mg/g, and total protein content in the range of 14.0 ± 0.5 to 22.0 ± 1.1 mg/g. Radical scavenging capacities of the Salvia species were determined in the range of 84.1 ± 4.5 to 96.8 ± 0.1%. Moreover, Salvia extracts showed powerful antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. Cytotoxic effects of the samples on human lymphocytes were determined by MTS assay and S. kronenburgii and S. euphratica var. euphratica decreased the harmful effects of 2-hydroperoxy-2-methylpropane (tert-butyl hydroper-oxide, t-BOOH) at all time points tested. The highest amounts of rutin hydrate belong to S. kronenburgii and S. euphratica var. euphratica , and the highest amounts of luteolin-7-glucoside belong to S. huberi and S. kronenburgii . Vanillic acid was present only in S. huberi and S. kurdica .

The subject of this study is the composition of low-molecular-weight metabolites in downy birch ( Betula pubescens ) buds and their participation in protection from various kinds of stress. Using the GC-MS, 640 compounds were detected, of which 314 were identified in downy birch buds for the first time. The volatile components detected using the SPME technique mainly consisted (about 70% of the total ionic current of the chromatogram, TIC) of mixtures of sesquiterpenoids. The exudate covering the buds, along with sesquiterpenoids (approximately 60% of TIC), included flavonoids (25% of TIC). The main part of the material extracted by supercritical carbon dioxide from buds comprised sesquiterpenoids and triterpenoids (47 and 28% of TIC, respectively). Via column chromatography, 25 known compounds (mainly flavonoids and triterpenoids) were isolated, most of which were first discovered in the buds of downy birch. Many compounds of these classes have strong biological activity and probably either directly or indirectly perform a protective function in birch buds. An assumption is made about the biological role of a number of secondary metabolites (such as volatile isomeric megastigmatriens and triterpene seco -acids) as well as about these compounds’ possible means of biosynthesis, which were first discovered in the buds of downy birch.

Agelanthus brunneus (Loranthaceae) is a hemiparasitic plant growing on Senna siamea (Fabaceae). The chemical investigation of its leaves and flowers led to the isolation of one new phenolic compound namely (−)-brunneusine ( 1 ), together with 13 known compounds. The crude leaves and flowers extracts (CLE and CFLE) with their ethyl acetate fractions (EAFL and EAFFL) and some isolated compounds ( 1–3 ; 8–9 and 11–14 ) have been tested on four bacterial species of sanitary importance isolated in an aquatic environment. All the samples except compound 3 showed antibacterial activity with MICs ranging from 0.43 to 8.88.10 3  µg/mL and MBCs from 0.43 to 3.55.10 3  µg/mL. Compounds 9 and 14 showed better activity on all bacterial species tested with MICs ranging from 0.43 to 27.77 µg/mL. Only CLE, EAFL and compounds 14 , 2 , 8 and 9 showed bactericidal effects on all bacterial species tested.

MAO-A inhibitors are used in the treatment of depression. There are many studies showing that the thiazolyl-hydrazone structure is a pharmacophore structure for the MAO enzyme. In previous studies by our team, activity studies were carried out with thiazolyl-hydrazone derivatives containing pyrrolidine, morpholine, and piperazine. All of them were displayed MAO-A selective inhibition profile. Additionally, derivatives containing piperazine ring were most active. For this purpose, thiazolyl-hydrazone derivatives containing piperazine were synthesized, but this time an active group, formyl group, was added to the piperazine ring as a substituent. Based on this view, new thiazolyl-hydrazone compounds were synthesized, characterized, and screened for their h MAO-A and h MAO-B inhibitory activity by an in vitro fluorometric method. The structure of the compound was tried to be fully elucidated using 2D NMR technique. The compound including 2,4-dimethyl substituent ( 3i ) were found to be the most effective agents in the series against MAO-A enzyme with the IC 50 value of 0.080 ± 0.003 µM. The docking study of compound 3i revealed that there is a strong interaction between the active sites of h MAO-A and analyzed compound.