An Overview of the Synthesis and Antimicrobial, Antiprotozoal, and Antitumor Activity of Thiazole and Bisthiazole Derivatives.

Thiazole, a five-membered heteroaromatic ring, is an important scaffold of a large number of synthetic compounds. Its diverse pharmacological activity is reflected in many clinically approved thiazole-containing molecules, with an extensive range of biological activities, such as antibacterial, antifungal, antiviral, antihelmintic, antitumor, and anti-inflammatory effects. Due to its significance in the field of medicinal chemistry, numerous biologically active thiazole and bisthiazole derivatives have been reported in the scientific literature. The current review provides an overview of different methods for the synthesis of thiazole and bisthiazole derivatives and describes various compounds bearing a thiazole and bisthiazole moiety possessing antibacterial, antifungal, antiprotozoal, and antitumor activity, encouraging further research on the discovery of thiazole-containing drugs.

Phytochemical Analysis, Antioxidant and Antimicrobial Activities of Helichrysum arenarium (L.) Moench. and Antennaria dioica (L.) Gaertn. Flowers.

Antennaria dioica (L.) Gaertn. and Helichrysum arenarium (L.) Moench. are two species of the Asteraceae family, known in Romanian traditional medicine for their diuretic, choleretic, and anti-inflammatory properties. The aim of the present study was to evaluate the phenolic and sterolic composition of flowers from the two species and to assess their antioxidant, antibacterial and antifungal properties. LC-MS analyses were performed on methanolic, ethanolic and 70% v/v ethanolic extracts, before and after acid hydrolysis, and revealed high amounts of polyphenols. Chlorogenic acid was found as the main compound for the flowers of A. dioica (502.70 ± 25.11 mg/100 g d.w.), while quercitrin was dominant in H. arenarium (424.28 ± 21.21 mg/100 g d.w.) in 70% v/v ethanolic extracts before hydrolysis. Antioxidant capacity assays showed an important antioxidant potential, which can be correlated with the determined polyphenolic compounds, showing the 70% v/v ethanolic extracts of the two species as being the most effective antioxidant samples for the DPPH assay. Antibacterial and antifungal assays confirm a modest biological potential for the same extract of both species. Results obtained in the present study bring important data and offer scientific evidence on the chemical composition and on the biological activities of the flowers belonging to the two species.

Evaluation of Polyphenolic Content, Antioxidant and Diuretic Activities of Six Fumaria Species.

Romanian traditional medicine describes the use of aerial parts of Fumaria species to treat hepatobiliary diseases as well as diuretic agents. The present study aims to investigate the chemical composition, antioxidant properties, and diuretic effects of several Fumaria species. LC/MS analysis revealed that Fumaria species contain phenolic acids and high amounts of flavonoids with rutin and isoquercitrin as main compounds. Concerning antioxidant capacity, the most significant results were obtained for F. capreolata and F. vailantii. Both species showed a good correlation between the antioxidant capacity and a high amount of flavonoids. Furthermore, the extracts of F. officinalis and F. schleicheri produced a strong increase in urinary volumetric excretion of saline-loaded rats, 24 h after the oral administration of a single dose of 250 mg/kg bw. Moreover, both extracts of F. officinalis and F. schleicheri increased the urinary excretion of Na⁺ and K⁺. Results from the present study offer a new perspective concerning the chemical composition and bioactivities of traditionally used fumitory species.

Phytochemical Characterization of Veronica officinalis L., V. teucrium L. and V. orchidea Crantz from Romania and Their Antioxidant and Antimicrobial Properties.

Aerial parts of Veronica species are used in Romanian traditional medicine for the treatment of various conditions like kidney diseases, cough, and catarrh, and are known for their wound-healing properties. In the present study, the phenolic and sterolic content and the antioxidant and antimicrobial activities of three Veronica species (Plantaginaceae), V. officinalis L., V. teucrium L. and V. orchidea Crantz, were studied. The identification and quantification of several phenolic compounds and phytosterols were performed using LC/MS techniques and the main components were p-coumaric acid, ferulic acid, luteoline, hispidulin and ß-sitosterol. More than that, hispidulin, eupatorin and eupatilin were detected for the first time in the Veronica genus. Nevertheless, representatives of the Veronica genus were never investigated in terms of their phytosterol content. The antioxidant potential investigated by Trolox equivelents antioxidant capacity (TEAC) and EPR spectroscopy revealed that V. officinalis and V. orchidea extracts presented similar antioxidant capacities, whilst the values registered for V. teucrium extract are lower. Regarding the antimicrobial activity of the investigated species, Staphylococcus aureus, Listeria monocytogenes and Listeria ivanovii were the most sensitive strains with MIC values between 3.9 and 15.62 mg/mL. The results obtained by this study may serve to promote better use of representatives from the genus Veronica as antioxidant and antimicrobial agents.

Comparative studies on polyphenolic composition, antioxidant and antimicrobial activities of Schisandra chinensis leaves and fruits.

The aim of this paper was to evaluate the antioxidant and antimicrobial activities and the polyphenolic content of Schisandra chinensis (Turcz.) Baill. leaves and fruits. The leaves are an important source of flavonoids (35.10 ± 1.23 mg RE/g plant material). Qualitative and quantitative analyses of the polyphenolic compounds were achieved using a HPLC-UV-MS method. The main flavonoid from the leaves was isoquercitrin (2486.18 ± 5.72 µg/g plant material), followed by quercitrin (1645.14 ± 2.12 µg/g plant material). Regarding the fruit composition, the dominant compound there was rutin (13.02 ± 0.21 µg/g plant material), but comparing with the leaves, fruits can be considered a poor source of phenolic compounds. The antioxidant activity was evaluated by DPPH, TEAC, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c and EPR spectroscopic assays, revealing a better antioxidant activity for the S. chinensis leaves extract. In the antimicrobial assay, S. chinensis leaves extract showed efficient activities against the targeted bacteria, being more active than the fruits extract. The results suggest the leaves of S. chinensis as a valuable source of antioxidant compounds with significant antioxidant activity.

Morphological and Functional Outcomes after Intravitreal Dexamethasone Injection for Macular Edema in Patients with Central Vein Occlusion at 48-Week Follow-Up.

PURPOSE: The purpose of the study was to assess the efficacy of intravitreal dexamethasone implant (IDI: Ozurdex®) injection in eyes with macular edema due to retinal vein occlusion. Material and Method. A retrospective, nonrandomized study was conducted in patients with macular edema (ME) due to retinal vein occlusion (RVO) who undertook intravitreal Ozurdex® as first-line treatment. We performed a complete ocular exam including macular OCT. RESULTS: The mean BCVA (logMar) improved from 0.420.42 ± 0.23 logMar at baseline to 0.21 ± 0.23 logMar at 48 weeks in the BRVO group and from 0.72 ± 0.16 logMar at baseline to 0.31 ± 0.23 logMar at 48 weeks in the CRVO group. In both groups, CFT values decreased significantly compared to baseline (p < 0.0001 at each timepoint). Reinjection for recurrent macular edema after 18 weeks was indicated in five eyes (41.67%) in the BRVO group and in six eyes (25%) in the CRVO group. Cataract developed in two eyes (16.67%) in the BRVO group and in one eye (4.17%) in the CRVO group. The IOP was higher than 25 mmHg in two cases in the BRVO group (16.66%) and in three cases (8.33%) in the CRVO group. CONCLUSION: Ozurdex® injected intravitreally significantly improved the mean CFT and BCVA in eyes with macular edema due to retinal vein occlusion.

Treatment beyond progression in metastatic colorectal cancer: to double or not to double the dose of bevacizumab?

PURPOSE: Bevacizumab or cetuximab represent the standard treatment in association with classical chemotherapy in confirmed metastatic colorectal cancer (mCRC). Bevacizumab could be continued after the first disease progression with an overall survival (OS) advantage, compared to chemotherapy alone, but the optimal dose remains a debatable issue. METHODS: In a retrospective analysis of mCRC patients treated with bevacizumab, we selected patients with administration beyond progression, and stratified them according to the dose received- same dose bevacizumab (SDB) as first-line chemotherapy or double dose bevacizumab (DDB). For each group we evaluated OS, time to treatment failure (TTF) and progression-free survival in the first-line (PFS1) and in the second-line (PFS2). RESULTS: In the first-line therapy, oxaliplatin backbone regimen was used in 73% SDB, compared with 22.5% DDB patients, while irinotecan was used in 75% DDB and 27% SDB patients. Second-line oxaliplatin was given to 50% DDB and 29.7% SDB patients, while irinotecan was administered to 47.5% DDB and 70.3% SDB patients. The median values were: OS - 41 months in the DDB group and 25 months in the SDB group (p = 0.01); TTF - 24 months in the DDB group and 19 months in the SDB group (p=0.009); PFS1 - 17 months in the DDB group and 12 months in the SDB group (p=0.008); PFS2 - 9 months in the DDB group and 5 months in the SDB group (p = 0.03). CONCLUSIONS: Doubling the dose of bevacizumab at progression seems to provide OS and PFS advantage for mCRC patients.

Biological and Chemical Insights of Beech (Fagus sylvatica L.) Bark: A Source of Bioactive Compounds with Functional Properties.

The present study aimed, on the one hand, to improve the yield of microwave assisted extraction (MAE) of polyphenols from beech bark by using a design of experiments (DoE) approach. On the other hand, beech bark extracts (BBE) were characterized in terms of their phytochemical profile and evaluated for biological potential (antioxidant, antibacterial, antifungal, antimutagen, anti-α-glucosidase, and anti-tyrosinase). The extraction time varies with the amount of extracted total phenolic content (TPC). The microwave power favors TPC extraction but in different proportions. The optimum conditions which gave the highest TPC (76.57 mg GAE/g dry plant material) were reached when the microwave power was 300 W, extraction time was 4 min, and the solvent was an ethanol-water (50:50) mixture. The practical value of TPC after a controlled experiment was 76.49 mg GAE/g plant material. The identified compounds were vanillic acid, gallic acid, epicatechin, catechin, protocatechuic acid, chlorogenic acid, ferulic acid, and isoquercitrin. The antioxidant potential of BBEs was demonstrated by in vitro experiments. The BBEs were active against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli, and Candida species. All extracts were antimutagenic and expressed an inhibition on α-glucosidase and tyrosinase activity. Regarding antimutagen activity, the assayed extracts may be considered to have low or no antimutagen effects.