Promising Algerian essential oils as natural acaricides against the honey bee mite Varroa destructor (Acari: Varroidae).

Varroosis induced by Varroa destructor Anderson and Trueman represents the most pathogenic and destructive disease affecting the western honey bee, Apis mellifera. In this study, we investigated the acaricidal activity against the Varroa mite using essential oils (EOs) from the aerial parts of four autochthonous Algerian herbal species, namely Artemisia herba alba, Artemisia campestris, Artemisia judaica and Ruta montana. EOs were obtained by means of hydrodistillation and their composition was characterized by gas chromatography-mass spectrometry. The toxicity of the selected EOs toward V. destructor and A. mellifera adult honey bees was evaluated using the complete exposure method. The results indicate the predominance of davanone (66.9%) in A. herba alba, ß-pinene (19.5%) in A. campestris, piperitone (68.7%) in A. judaica and 2-undecanone (70.1%) in R. montana EOs. Interestingly, the LC50 values coupled to bee mortality rates revealed that all tested oils exhibited significant acaricidal efficiency with selectivity ratio (SR) values of 10.77, 8.78, 5.62 and 3.73 for A. campestris, A. judaica, A. herba alba, and R. montana, respectively. These values were better than that of thymol (SR = 3.65), the positive control. These findings suggest that these EOs could be used as plant-derived veterinary acaricides to control varroosis in field conditions.

Selective Induction of DNA Damage and Cell Cycle Arrest Mediated by Chromone-Triazole Dyads Derivatives: Effects on Breast and Prostate Cancer Cells.

Chromones and triazoles are groups of heterocyclic compounds widely known to exhibit a broad spectrum of biological activities. The combination of these two pharmacophores could result in multiple mechanisms of action to increase the potency of anticancer drugs and reduce their side effects. The in vitro antitumor effect of eight chromone-based compounds was evaluated in breast (T-47D and MDA-MB-231) and prostate (PC3) cancer cell lines, and in non-cancerous human mammary epithelial cells (HuMEC) using a resazurin-based method. Flow cytometry was used to evaluate the cell cycle and cell death, and É£-H2AX detection to identify DNA damage. The compounds showed selective cytotoxicity against cancer cell lines, with (E)-2-(2-(5-(4-methoxyphenyl)-2H-1,2,3-triazol-4-yl)vinyl)-4H-chromen-4-one (compound 2 a) being more potent in non-metastatic T-47D cells (IC50 0.65 µM). Replacing the hydrogen by a methyl group on the triazole ring in compound 2 b enhanced the cytotoxic activity up to IC50 0.24 µM in PC3, 0.32 µM in MDA-MB-231 and 0.52 µM in T-47D. Compound 2 b was 3-fold more potent than doxorubicin in PC3 (IC50 0.73 µM) and 4-fold in MDA-MB-231 (IC50 1.51 µM). The addition of tetrahydroisoindole-1,3-dione moiety in compound 5 did not improve its effectiveness in any of the cell lines but it exerted the lowest cytotoxic effect in HuMEC (IC50 221.35 µM). The compounds revealed different cytotoxic mechanisms: 2 a and 2 b induced G2/M arrest, and compound 5 did not affect the cell cycle.

Facile green in situ hemisynthesis of new chiral chromeno-pyrimidine derivatives: antibacterial, antioxidant activities and molecular docking study.

A hemisynthesis 'in situ' reaction of (thio)barbituric acids with an α,ß-unsaturated aldehyde using perillaldehyde from Ammodaucus leucotrichus essential oil, afforded chromeno-pyrimidine derivatives B-1 and B-2. The reaction was carried out in water and water/ethanol medium without a catalyst. The obtained pyrimidines were identified by their spectral 1H,13C, Dept-135, HMBC, HSQC, COSY, and NOESY 2D. The antioxidant activity of both compounds was evaluated using different in vitro methods (DPPH, ABTS, and CUPRAC). The hemisynthesized molecules exhibited a bacteriostatic effect against ten tested gram (+) and gram (-) strains. According to the molecular docking analysis, B-1 showed lower binding energies compared to B-2 against (PDB: 1HD2) and (PDB: 1KZN) targets, which is in agreement with the ABTS and E. Coli assays. Furthermore, a probable promising anti-HIV activity was noticed against reverse transcriptase (PDB: 2RKI), a key enzyme for HIV replication. The ADME properties calculations showed no Lipinski's rule violation for both compounds.