Novel Anti-tumor Strategy for Breast Cancer: Synergistic Role of Oleuropein with Paclitaxel Therapeutic in MCF-7 Cells

BACKGROUND

The side effects of conventional therapeutics pose a problem for cancer treatment. Recently, combination treatments with natural compounds have attracted attention regarding limiting the side effects of treatment. Oleuropein is a natural polyphenol in olives that has antioxidant and anticancer effects.

OBJECTIVES

This study aimed to investigate the oxidative stress effect of a combination of Paclitaxel, a chemotherapeutic agent, and Oleuropein in the MCF-7 cell line.

METHODS

The xCELLigence RTCA method was used to determine the cytotoxic effects of Oleuropein and Paclitaxel in the MCF-7 cell line. The Total Oxidant and Total Antioxidant Status were analyzed using a kit. The Oxidative Stress Index was calculated by measuring Total Oxidant and Total Antioxidant states. The levels of superoxide dismutase, reduced glutathione and malondialdehyde, which are oxidative stress markers, were also measured by ELISA assay kit.

RESULTS

As a result of the measurement, IC50 doses of Oleuropein and Paclitaxel were determined as 230 μM and 7.5 μM, respectively. Different percentages of combination ratios were generated from the obtained IC50 values. The effect of oxidative stress was investigated at the combination rates of 10%, 20%, 30%, and 40% which were determined to be synergistic. In terms of the combined use of Oleuropein and Paclitaxel on oxidative stress, antioxidant defense increased, and Oxidative Stress Index levels decreased.

CONCLUSION

These findings demonstrate that the doses administered to the Oleuropein+Paclitaxel combination group were lower than those administered to groups using one agent alone (e.g. Paclitaxel), the results of which reduce the possibility of administering toxic doses.

Day and Night Fluctuations in GABA Biosynthesis Contribute to Drought Responses in Nicotiana tabacum L

When synchronized with the light/dark cycle the circadian rhythm is termed a diurnal rhythm and this organizes an organism's daily life cycle in relation to the metabolic shifts during the day/night cycles. This is a complex task, particularly under stress conditions. Accurate maintenance of the diurnal rhythm becomes an issue under environmental extremes, such as drought due to the impairment of metabolism, redox balance, and structural integrity. In plants, the non-proteinogenic amino acid GABA accumulates to high levels in response to several stress factors but this is not always dependent on the activation of its biosynthesis. Here we propose a regulatory role to GABA during the diurnal rhythm in plants which is similar to its function in animals where it adjusts the circadian rhythm. Here we investigated whether GABA-biosynthesis was affected by drought stress during the diurnal cycle. For this, we took samples from leaves of N. tabacum plants subjected to PEG-mediated drought stress (-0.73 MPa) during the day and night cycle during a 24 hour period. Glutamate, GABA, and proline contents, along with GDH, GAD enzyme activities and transcript profiles were analyzed. Overall, we conclude that the oscillations in GABA biosynthesis during day and night cycle have an impact on drought stress responses which needs to be elucidated by further analysis.

Biofilm formation, icaABCD genes and agr genotyping of Staphylococcus aureus from fish and ground beef

A total of 46 Staphylococcus aureus isolates from fish and ground beef were tested for the agr types, icaABCD genes, and biofilm formation at 12, 25 and 37 °C by the microtiter plate and the MTT assays. All isolates were positive for the icaABD genes, while 97.8% were positive for the icaC. All isolates produced biofilms at 37 and 25 °C, but 93.5% of them were also biofilm producers at 12 °C. There was no significant difference in biofilm formation between 25 and 37 °C using the crystal violet assay (P > 0.05). However, statistically significant differences were detected between 12 and 25 °C as well as 12 and 37 °C (P < 0.05). All isolates were significantly different in biofilm production by the MTT assay at all tested temperatures. Furthermore, a relationship between the presence of the icaABCD genes and biofilm formation was observed. The agr type I was the most prevalent (54.4%) among the isolates, followed by agr type II (41.3%) and agr type III (9.6%). In this study, the S. aureus isolates exhibited biofilm formation ability responsible for persistence of bacteria in foods, which may lead to food spoilage and human health problems.

Apoptotic effects of ε-viniferin in combination with cis-platin in C6 cells

Glioblastoma (GBM) is one of the most common and lethal forms of primary brain tumors in human adults. Treatment options are limited, and in most cases ineffective. Natural products are sources of novel compounds endowed with therapeutic properties in many human diseases like cancer. ε-viniferin is a resveratrol dimer and well known for having antiproliferative and apoptotic effects on cancer cells. Cisplatin is a platinum containing anti-cancer drug. In this study, we aimed to investigate antiproliferative and apoptotic effects of using cis-platin and ε-viniferin alone or in combined treatment of C6 cells. Cell proliferation was detected by WST-1. Mitochondrial membrane potential changes in the cells (ΔΨm) were evaluated using cationic dye JC1. Apoptotic index which is a hallmark of late apoptosis was detected by using Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method and apoptotic alterations were observed by transmission electron microscope (TEM). Activation of caspase-8, -9, -3 in C6 cells at various incubation periods was measured by flow cytometer. Apoptotic index increased at highest level in only combined treatment cells (91.6%) after 48 h incubation. These results were supported by TEM images. Caspase-8 activation in C6 cells increased to a maximum (12.5%) after 6 h by using combined cis-platin/ε-viniferin treatment (13.25/95 μM). Caspase-9 was activated at 44.5% after combined treatment for 24 h. This rate is higher than using cis-platin (14.2%) or ε-viniferin (43.3%) alone. The combined 13.25 μM/cisplatin and 95 μM ε-viniferin treatment caused maximum caspase-3 activation in C6 cells (15.5%) at the end of the 72 h incubation. In conclusion, it was observed that caspase-8, -9, -3 activation which was determined in vitro, trigerred apoptotic mechanism in C6 cells by using low concentrations of combined cis-platin and ε-viniferin.

Clinical features of patients diagnosed with degenerative rotator cuff tendon disease: a 6-month prospective-definitive clinical study from turkey

[Purpose] In rotator cuff tendon disease (RCTD), anamnesis is as important as clinical findings and anatomic/radio diagnostic examination. This study aimed to investigate the clinical features of patients diagnosed with RCTD using clinical and radiological methods between March 2015 and August 2015 at Malatya Research and Training Hospital Physical Medicine and Rehabilitation department. [Subjects and Methods] The study included 178 patients who were diagnosed with RCTD (128 females and 50 males). A questionnaire comprising 33 questions was given to each patient. [Results] Eighty-eight of the patients (49.9%) had an involvement on their right side, eighty-four (47.1%) had an involvement on their left side, and 6 had bilateral involvement. Mean visual analog scale (VAS) score was found to be statistically significant in favor of female patients. A statistically significant correlation was found between educational status and VAS. The body mass index (BMI) of the female patients was found to be higher than that of the male patients. Statistically significant correlation between doing risky work and gender showed that males were at a higher risk. [Conclusion] RCDT is more seen in people who have high BMI and are at their 50s. Pain complaint and BMI were found higher in female patients. DM, thyroid and cardiac diseases were seen more in the patients who are diagnosed with RCTD relative to the healthy population.

Association between radionuclides (210Po and 210Pb) and antioxidant enzymes in oak (Quercus coccifera) and mastic tree (Pistacia lentiscus)

The activity levels of naturally occurring radionuclides Polonium-210 and lead-210 in different subjects including plant species have direct or indirect impact on human beings. High levels of ionising radiation cause oxidative stress and the interaction between antioxidative defense and radionuclides is not well established in plant systems. In this study, we aimed to understand the impact of oxidative stress caused by ²¹⁰Po and ²¹⁰Pb in two Mediterranean plants; Quercus coccifera and Pistacia lentiscus. We analysed the constitutive and seasonal levels of ²¹⁰Po, ²¹⁰Pb, lipid peroxidation levels, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the field-collected samples. The highest activity concentrations of ²¹⁰Po and ²¹⁰Pb were detected in both plants in summer and Q. coccifera had higher levels than that of P. lentiscus. SOD and APX activity trends were different between oak and mastic; as compared to P. lentiscus, Q. coccifera efficiently used the two major components of antioxidative defense. Lipid peroxidation levels were low in both plants in all seasons except that of spring which were in good agreement with high antioxidant enzyme activities. In conclusion, we found that high ²¹⁰Po and ²¹⁰Pb activity concentrations in oak and mastic did not interfere with their growth and life cycles. The ability of both plants for survival and adaptation to Mediterranean environmental constraints provided an additional advantage for coping radionuclide induced oxidative stress as well.

Molecular characterization and detection of enterotoxins, methicillin resistance genes and antimicrobial resistance of Staphylococcus aureus from fish and ground beef

A total of 120 samples including 40 freshwaterfish(Oncorhynchus mykiss), 40 seawater fish (Sparus aurata) and 40 ground beef samples were examined for the presence of Staphylococcus aureus. The isolates were identified using biochemical tests and a PCR for the species-specific fragment (Sa442) and thermonuclease gene (nucA). The presence of staphylococcal enterotoxin genes (sea, seb, sec, sed and see), toxin genes (eta, etb, tsst), methicillin resistance gene (mecA) and some phenotypic virulence factors was also tested. Genotypic characterization of the isolates was analyzed by PCR-RFLP of the coa gene. Overall, 36 (30%) meat samples were contaminated with S. aureus. Of the 36 isolates, 3 (8.3%) were found to be positive for enterotoxin genes. Only 1 isolate (5.9%) from ground beef had the sea gene. In addition, 1 (12.5%) of the freshwater fish and 1 (9.1%) of the seawater fish carried both the sea and sed genes. The presence of seb, sec, see, eta, etb and tsst was not detected among the isolates of S. aureus. The amplified coa gene revealed five different clusters. Seven and six distinct RFLP patterns were obtained with AluI and HaeIII digestion, respectively. All isolates were found to be positive for slime, hemolytic and DNase activity while 41.7% of them were beta-lactamase positive. The presence of methicillin resistance was neither detected by PCR nor the disk diffusion method. A total of 94.4% of the isolates were resistant to at least one antimicrobial while 44.4% of them were resistant to at least two or more antimicrobials.

Oxidative stress and antioxidant responses to progressive resistance exercise intensity in trained and untrained males

The relationship between oxidative stress and some exercise components of resistance exercise (e.g. intensity, exercise volume) has not been clearly defined. Additionally, the oxidative stress markers may respond differently in various conditions. This study aims to determine the effects of progressive intensity of resistance exercise (RE) on oxidative stress and antioxidants in trained and untrained men, and also to investigate the possible threshold intensity required to evoke oxidative stress. RE trained (N=8) and untrained (N=8) men performed the leg extension RE at progressive intensities standardized for total volume: 1x17 reps at 50% of one-repetition maximum (1RM); 1x14 reps at 60% of 1RM; 1x12 reps at 70% of 1RM; 2x5 reps at 80% of 1RM; and 3x3 reps at 90% of 1RM. Blood samples were drawn before (PRE) and immediately after each intensity, and after 30 minutes, 60 minutes and 24 hours following the RE. Lipid-hydroperoxide (LHP) significantly increased during the test and then decreased during the recovery in both groups (p<0.05); the POST-24 h LHP level was lower than PRE-LHP. Protein carbonyl (PCO) and superoxide dismutase (SOD) significantly increased (p<0.05); however, 8-hydroxy-2’-deoxyguanosine (8-OHdG) and glutathione (GSH) were not affected by the RE (p > 0.05). The results indicated that there was no significant training status x intensity interaction for examined variables (p > 0.05). Standardized volume of RE increased oxidative stress responses. Our study suggests that lower intensity (50%) is enough to increase LHP, whereas higher intensity (more than 80%) is required to evoke protein oxidation.

The impact of GABA in harpin-elicited biotic stress responses in Nicotiana tabaccum

Harpin is a bacterial elicitor protein that was first isolated from Erwinia amylovora. Infiltration of this elicitor into the leaves of plants activates systemic acquired resistance against a variety of plant pathogens via the salicyclic acid defense pathway. The non-protein amino acid, neurotransmission inhibitor molecule of mammals-GABA- is found in all organisms and is known to be an important component of stress responses in plants. We hypothesized a possible interaction between harpin-induced defense responses and GABA shunt. Therefore, we conducted experiments on harpin-infiltrated tobacco and analyzed the components of GABA shunt in relation to growth, photosynthesis and H2O2 levels. RGR, RWC and photosynthetic efficiency were all affected in harpin-infiltrated tobacco leaves, but the rate of decline was more remarkable on RGR. H2O2 levels showed significant difference on 7 days after harpin infiltration when the necrotic lesions were also visible. GABA accumulation was increased and glutamate levels were decreased parallel to the differences in GDH and GAD enzyme activities, especially on days 5 and 7 of harpin infiltration. Transcript abundance of GDH and GAD encoding genes were differentially regulated in harpin-infiltrated leaves as compared to that of control and mock groups. In the present study, for the first time we showed a relationship between harpin-elicited responses and GABA in tobacco that was not mediated by H2O2 accumulation. Harpin infiltration significantly induced the first components of the GABA shunt such as GDH, GAD, glutamate and GABA in tobacco.

Direct and protective effects of single or combined addition of vincristine and ε-viniferin on human HepG2 cellular oxidative stress markers in vitro

The objective of this study is to examine the direct effects of low doses and high doses of ε-viniferin, a substance known to be an antioxidant, and vincristine sulphate, a chemotherapeutic agent, alone and in combination [ε-viniferin + vincristine] on HepG2 cell strain, as well as evaluate oxidative stress after incubation periods of 3, 6, and 24 h. Direct effect was determined right after the incubation period; however, for protective effect, antioxidant protection response was determined after the treatment for 1 h with 500 μM H2O2, which is an oxidative stressor. For this purpose, superoxide dismutase was determined for enzyme activity, and lipid hydroperoxide (LPO) and reduced glutathione concentrations were studied as indicators of oxidative stress. Results show that low [3.63 µM vincristine + 3.75 µM ε-viniferin] and high [11.25 µM vincristine + 15.8 µM ε-viniferin] doses of combination groups showed similar direct antioxidant effect on LPO levels as protective when compared to the H2O2 control group (p < 0.05). Superoxide dismutase enzyme showed a direct antioxidant effect in low and high dose combination groups. In addition, when the incubation period was increased to 24 h, a protective effect was observed in both dose groups (p < 0.05). Reduced glutathione activities showed a direct effect in the low dose combination group, and a protective effect in both the low and high doses in the 24 h. These results show that combined usage of drugs in HepG2 cell strain possesses a protective effect against exogenically produced oxidative stress conditions.

Glycine betaine protects tomato (Solanum lycopersicum) plants at low temperature by inducing fatty acid desaturase7 and lipoxygenase gene expression

Cold stress is among the environmental stressors limiting productivity, yield and quality of agricultural plants. Tolerance to cold stress is associated with the increased unsaturated fatty acids ratio in the plant membranes which are also known to be substrates of octadecanoid pathway for jasmonate and other oxylipins biosynthesis. Accumulation of osmoprotectant, glycine betaine (GB) is well known to be effective in the protecting membranes and mitigating cold stress effects but, the mode of action is poorly understood. We studied the role of GB in cold stress responses of two tomato cultivated varieties; Gerry (cold stress sensitive) and T47657 (moderately cold stress tolerant) and compared the differences in lypoxygenase-13 (TomLOXF) and fatty acid desaturase 7 (FAD7) gene expression profiles and physiological parameters including relative growth rates, relative water content, osmotic potential, photosynthetic efficiency, membrane leakage, lipid peroxidation levels. Our results indicated that GB might have a role in inducing FAD7 and LOX expressions for providing protection against cold stress in tomato plants which could be related to the desaturation process of lipids leading to increased membrane stability and/or induction of other genes related to stress defense mechanisms via octadecanoid pathway or lipid peroxidation products.

Towards novel anti-tumor strategies for hepatic cancer: ɛ-viniferin in combination with vincristine displays pharmacodynamic synergy at lower doses in HepG2 cells

Hepatocellular carcinoma is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. The efficacy of novel combination treatments are increasingly evaluated with use of integrative biology research and development (R&D) strategies and methodological triangulation. We investigated the anti-tumor effect of ɛ-viniferin alone, and the putative synergy of ɛ-viniferin with vincristine on the growth of HepG2 cells in vitro. Growth inhibition and apoptosis induction were determined by MTT assay and annexin V/propidium iodide (PI), respectively. Morphological changes and DNA fragmentation were investigated under electron microscopy and by agarose gel electrophoresis, respectively. The results collectively showed that treating cells with ɛ-viniferin and vincristine significantly inhibited cell viability at lower doses as compared to each agent applied alone. IC(50) values for ɛ-viniferin and vincristine were determined as 98.3 and 52.5 μM at 24 h, respectively. IC(50) value of ɛ-viniferin in combination with vincristine was 15.8+11.25 μM (mean/SD) at 24 h. The viability of cells treated with 17.9 μM vincristine alone for 24 h was 79.62%; it reduced to 26.53% when 25 μM ɛ-viniferin was added in combination with vincristine (p<0.05). We found that combination of drugs promoted the sensitivity of cells against to vincristine treatment. The effect of combined use was in support of a synergistic pharmacodynamic effect. Moreover, low doses of the combination regimen induced phosphatidyl re-localization, morphological changes, and DNA fragmentation, and therefore caused apoptotic death. This study thus suggests that low concentrations of ɛ-viniferin and vincristine can enhance the anti-tumor effects efficiently by inducing HepG2 cell apoptosis. Further studies in other model systems are warranted with a view to potential future applications in the clinic of such combination regimens and their putative mechanism of action in the observed synergy reported here.

Spoilage potentials and antimicrobial resistance of Pseudomonas spp. isolated from cheeses

Pseudomonas spp. are aerobic, gram-negative bacteria that are recognized as major food spoilage microorganisms. A total of 32 (22.9%) Pseudomonas spp. from 140 homemade white cheese samples collected from the open-air public bazaar were isolated and characterized. The aim of the present study was to investigate the biochemical characteristics, the production of extracellular enzymes, slime and β-lactamase, and antimicrobial susceptibility of Pseudomonas spp. isolated from cheeses. The identified isolates including Pseudomonas pseudoalcaligenes, Pseudomonas alcaligenes, Pseudomonas aeruginosa, Pseudomonas fluorescens biovar V, and P. pseudoalcaligenes ssp. citrulli were found to produce extracellular enzymes, respectively: protease and lecithinase production (100%), and lipase activity (85.7, 42.9, 100, and 100%, and nonlipolytic, respectively). The isolates did not produce slime and had no detectable β-lactamase activity. The antimicrobial susceptibility of the isolates was tested using the disk diffusion method. Pseudomonas spp. had the highest resistance to penicillin G (100%), then sulphamethoxazole/trimethoprim (28.1%). However, all Pseudomonas spp. isolates were 100% susceptible to ceftazidime, ciprofloxacin, amikacin, gentamicin, and imipenem. Multidrug-resistance patterns were not observed among these isolates. In this study, Pseudomonas spp., exhibiting spoilage features, were isolated mainly from cheeses. Isolation of this organism from processed milk highlights the need to improve the hygienic practices. All of the stages in the milk processing chain during manufacturing have to be under control to achieve the quality and safety of dairy products.