Liquidambar orientalis Mill. gum extract induces autophagy via PI3K/Akt/mTOR signaling pathway in prostate cancer cells.

Liquidambar orientalis Mill (LOM), is an endemic species having a local distribution in the southwestern coastal district of Turkey. Styrax liquidus gum (SLG), is a gum-like resinous which exudates in response to injury of the trunk of LOM. The aim of the study was to investigate the cytotoxic effects and the molecular mechanisms of the ethanolic SLG extract in human prostate cancer cells. GC-MS analysis was performed to identify the volatile compound composition. Cytotoxicity was determined by XTT analysis. Apoptosis and necrosis were evaluated via ELISA assay. Autophagic cell death was detected via monodansylcadaverine (MDC) staining and by measuring the levels of LC3I and LC3II. The protein levels of p-PI3K, p-Akt and p-mTOR were evaluated by western blot analysis. In the present study, it is shown that the SLG extract containing a considerable amount of ravidomycin derivate induced autophagic cell death in prostate cancer cells via inhibiting the PI3K/Akt/mTOR pathway.

Development of a spiramycin sensor based on adsorptive stripping linear sweep voltammetry and its application for the determination of spiramycin in chicken egg samples.

Herein, an adsorptive stripping linear sweep voltammetric technique was described to determine spiramycin, a macrolide antibiotic, using a carboxylic multiwalled glassy carbon electrode modified with carbon nanotubes. The main principle of the analytical methodology proposed was based on the preconcentration of spiramycin by open-circuit accumulation of the macrolide onto the modified electrode surface. As a result of the adsorption affinity of spiramycin to the modified surface, the sensitivity of the glassy carbon electrode was significantly increased for the determination of spiramycin. The electrochemical behavior of spiramycin was evaluated by cyclic voltammetry and the irreversible anodic peak observed was measured as an analytical signal in the methodology. The proposed electrochemical sensing platform was quite linear in the range of 0.100-40.0 µM of spiramycin concentration with a correlation coefficient of 0.9993. The limit of detection and the limit of quantification were 0.028 and 0.094 µM, respectively. The intra- and interday repeatability of the proposed sensor was within acceptable limits. Finally, the applicability of the electrochemical methodology was examined by determining the drug content of chicken egg samples spiked with spiramycin standard. A rapid and easy extraction technique was performed to extract spiked spiramycin from the egg samples. The extraction technique followed had good recovery values between 85.3 ± 4.0% and 93.4 ± 1.9%.

Development and Validation of an Analytical Methodology Based on Liquid Chromatography-Electrospray Tandem Mass Spectrometry for the Simultaneous Determination of Phenolic Compounds in Olive Leaf Extract.

A simple method was validated for the analysis of 31 phenolic compounds using liquid chromatography-electrospray tandem mass spectrometry. Proposed method was successfully applied to the determination of phenolic compounds in an olive leaf extract and 24 compounds were analyzed quantitatively. Olive biophenols were extracted from olive leaves by using microwave-assisted extraction with acceptable recovery values between 78.1 and 108.7%. Good linearities were obtained with correlation coefficients over 0.9916 from calibration curves of the phenolic compounds. The limits of quantifications were from 0.14 to 3.2 µg g-1. Intra-day and inter-day precision studies indicated that the proposed method was repeatable. As a result, it was confirmed that the proposed method was highly reliable for determination of the phenolic species in olive leaf extracts.

Determination of oleuropein using multiwalled carbon nanotube modified glassy carbon electrode by adsorptive stripping square wave voltammetry.

A multi-walled carbon nanotube modified glassy carbon electrode was used to prepare an electrochemical sensing platform for the determination of oleuropein. Results showed that, the accumulation of oleuropein on the prepared electrode takes place with the adsorption process. Electrochemical behavior of oleuropein was studied by using cyclic voltammetry. Compared to the bare GCE, the oxidation peak current of oleuropein increased about 340 times at MWCNT/GCE. Voltammetric determination of oleuropein on the surface of prepared electrode was studied using square wave voltammetry where the oxidation peak current of oleuropein was measured as an analytical signal. A calibration curve of oleuropein was performed between 0.01 and 0.70µM and a good linearity was obtained with a correlation coefficient of 0.9984. Detection and quantification limits of the method were obtained as 2.73 and 9.09nM, respectively. In addition, intra-day and inter-day precision studies indicated that the voltammetric method was sufficiently repeatable. Finally, the proposed electrochemical sensor was successfully applied to the determination of oleuropein in an olive leaf extract. Microwave-assisted extraction of oleuropein had good recovery values between 92% and 98%. The results obtained with the proposed electrochemical sensor were compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis.

Effects of Galium aparine extract on the cell viability, cell cycle and cell death in breast cancer cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE: Galium species have been traditionally used for its anti-cancer, antioxidant, anti-inflammatory, antimicrobial and cardioprotective effects in the folk medicine. Galium aparine (GA) is a typical climbing plant growing widespread in Anatolia. AIM OF THE STUDY: To investigate the potential anti-proliferative and apoptotic effect of GA methanol (MeOH) extract on MCF-7 and MDA-MB-231 human breast cancer cells and MCF-10A untransformed breast epithelial cells. MATERIALS AND METHODS: First, the extract was characterized by both liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF/MS) and gas chromatography-mass spectrometry (GC-MS) analyses. Then, cell viability and cell cycle distribution were investigated by XTT assay and PI staining by flow cytometry, respectively. Cell death was determined by Annexin V FITC/7-AAD staining. RESULTS: A total of 14 major phytochemicals were identified by LC/Q-TOF/MS and 34 volatile compounds were determined by GC-MS. The extract was cytotoxic in both breast cancer cell lines in a concentration and time dependent manner and showed G1 block after 72h extract treatment. However, it was not cytotoxic to MCF-10A breast epithelial cells. Flow cytometry analyses revealed that apoptosis was induced in MDA-MB-231 cells; however, necrosis was induced in MCF-7 cells. CONCLUSION: Our study suggests that GA MeOH extract may have potential anti-cancer effects against breast cancer cells without impairing normal breast epithelial cells. Ability to induction of non-apoptotic cell death besides apoptotic cell death by this complex plant-derived mixture may enable the killing of apoptosis resistant breast cancer cells but further studies should be conducted to investigate the bioavailability and metabolism of it in vivo.