Kadriye Sorkun

Protective effects of Turkish propolis on alcohol-induced serum lipid changes and liver injury in male rats

Abstract The chemical content of Turkish Castanea sativa propolis is investigated, along with its protective effect against alcohol-induced oxidative stress. The ethanol-propolis extract, at dose of 200 mg/kg body weight/day, was given, by gavage, to male rats for 15 days. At the end of the treatment, serum lipid levels, activities of liver enzymes and other biochemical parameters were measured. HDL level decreased and LDL level increased in the alcohol group, while HDL level increased and LDL level decreased in the alcohol+propolis group. There were decreases in cholesterol and triglyceride levels in the alcohol+propolis group. Also, there were decreases in ALP and AST enzyme activities, but LDH enzyme activity increased in the propolis treatment group compared to the alcohol group. No toxic effects of Turkish C. sativa propolis were found, while it caused an increase in HDL level and a decrease in LDL level. We suggest that these effects are protective against degenerative diseases and against alcohol-induced oxidative stress via free radicals.

Propolis from the Mediterranean Region: Chemical Composition and Antimicrobial Activity

Abstract The chemical composition of propolis from Bulgaria, Turkey, Greece and Algeria was investigated by GC-MS. All of them contained mainly flavonoids and esters of caffeic and ferulic acids, which indicated that their main source are buds of poplars of the taxonomic section Aegieros. Some Turkish samples contained a low percent of diterpenic acids, while in Algerian samples significant amounts of a hydroxyditerpenic acid (M=322, its structure not determined by its MS) were found. All samples showed significant antibacterial and weak to moderate antifungal activity.

Antibacterial Activity of Propolis versus Conventional Endodontic Disinfectants against Enterococcus faecalis in Infected Dentinal Tubules

INTRODUCTION The antibacterial activity against Enterococcus faecalis of 2 propolis samples was investigated in a dentin block model, and their effectiveness was compared with that of established endodontic disinfectants, chlorhexidine (CHX) and calcium hydroxide [Ca(OH)(2)]. METHODS Standardized dentin blocks were infected with E. faecalis ATCC 29212. The root canal space was filled with one of the ethanolic extracts of propolis (Artvin or Tekirdağ mix [TM]), CHX 2%, Ca(OH)(2), or ethanol or phosphate-buffered saline for control. Canal dentin was sampled after 1 or 7 days by using a standard-size bur. The dentinal shavings were vortexed vigorously in phosphate-buffered saline, and aliquots were cultured on tryptone soy agar plates. Colonies were counted after 2 days of incubation. Statistical significance was set to 5%. RESULTS All experimental agents significantly reduced the number of the cultivable bacteria. CHX was the most potent disinfectant at both times. Compared with the ethanol control, no significant reduction in the number of colonies was found for the propolis extracts at day 1; however, significant reduction was found at day 7. The 2 propolis samples were statistically similar to each other and to Ca(OH)(2), but the TM sample was also similar to CHX at day 7. This has been linked to the greater concentration of flavonoids, a group of antibacterially active compounds, in the TM sample as determined by gas chromatography-mass spectrometry analysis. CONCLUSIONS The antimicrobial activity of the propolis samples tested in this study was between Ca(OH)(2) and CHX. Both propolis samples were antimicrobially effective; however, their activity did not exceed CHX.

Propolis from Turkey induces apoptosis through activating caspases in human breast carcinoma cell lines

Propolis is a sticky substance that is collected from plants by honeybees that has anti-mutagenic and anti-carcinogenic properties with biological and therapeutic effects. The target of this study was to investigate the anti-apoptotic effect of propolis extracts (PE) on the caspase pathway in the human breast cell line MCF-7 in culture. Seven different propolis extracts, numbered PE 1-7, produced in their natural ecological environment, were collected from the Hacettepe University Beytepe Campus area in Ankara, Turkey. Individual extracts at 0.5, 0.25, 0.125 and 0.063mg/ml were incubated with MCF-7 cells during 2 days culture. Cell growth and cytotoxicity were measured colorimetrically by MTT assay. Apoptotic cell death was determined by the TUNEL method (terminal deoxynucleotidyltransferase-biotin nick end-labelling) and caspase activity was investigated by immunocytochemistry using antibodies directed against caspase 6, caspase 8 and caspase 9. The results showed that the PE 5 and 6 extracts at 0.125mg/ml dilution induced apoptosis in association with increased number of TUNEL positive cells. MTT results showed that cultures exposed to the same extracts and at the same dilution experienced better cell growth compared to those cultures exposed to the other extracts. Immunpositivity for all caspases was detected after treatment with all the extracts and at all dilutions, with stronger immunoreactivity for caspase 6 than caspases 8 and 9. Caspase 6 labelling was especially strong in PE 5 and PE 6. We conclude that propolis may have anti-tumour effects by increasing apoptosis through the caspase pathway. Such propolis extracts may be important economically and allow development of a relatively inexpensive cancer treatment.

Determination of Chemical Composition of Turkish Propolis

The aim of the present work is to study the chemical composition of Turkish propolis. Propolis samples were collected from different regions of Turkey (Bursa, Erzurum-Askale, Gumushane-Sogutagil and Trabzon-Caglayan) in 1999. Ethanol extracts of propolis (EEP) were prepared for chemical analysis, using gas chromatograph coupled with mass spectrometry (GC-MS). Our findings show that propolis samples from Trabzon and Gumushane region have a similar chemical composition. In both samples aromatic acids, aliphatic acids and their esters, and also ketone derivatives are the main compound groups. The chemical composition of the single sample that was collected from Erzurum region shows a very different pattern than the other two samples. In this propolis, the main compounds are aromatic acid esters and alcohols. However, it contains a high amount of amino acids compared to the other samples. The other samples collected from three different region of Bursa City are rich with flavavones, aromatic acids and their esters, terpenoids, flavones and ketones

The scolicidal effects of honey

Echinococcosis is a zoonosis that is caused by adult or larval tapeworms belonging to the genusEchinococcus. Until now, no studies have sought to determine the scolicidal effects of honey. Therefore, the present study was undertaken to explore the scolicidal effects of honey in different concentrations for various exposure times. Tubes that contained at least 500 protoscolices were supplemented with 1 %, 5%, 10%, 25%, and 50% concentrations of honey. Tubes were maintained at room temperature for 0.5, 1, 2, 3, 4, 5, and 10 min. At the end of the incubation times, the viability of protoscolices was assessed through a trypan blue exclusion test. The effective dose of honey was applied intraperitoneally to determine whether it caused an anaphylactic reaction or hyperglycemia. Honey concentrations of 10% or greater killed all protoscolices. The scolicidal effects of honey began at the end of the third minute. Honey did not cause adverse effects when applied intraperitoneally. In this study, an investigation of the scolicidal effects of honey showed that it is highly effective at a 10% concentration. On the basis of in vivo study results, the investigators concluded that honey is a potent scolicidal agent.

Immunomodulatory effects of Turkish propolis: changes in neopterin release and tryptophan degradation.

In most of the diseases which are considered to benefit from propolis, cellular immune reaction is activated, neopterin levels in body fluids are increased and enhanced tryptophan degradation is observed. In this study, the immunomodulatory effects of six Turkish propolis samples were evaluated by using the in vitro model of peripheral blood mononuclear cells (PBMC). Concentrations of neopterin, tryptophan, kynurenine and pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were determined and also the viability of the cells was checked with trypan blue and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test. In PBMC treated with mitogen phytohaemagglutinin, neopterin production and tryptophan degradation by enzyme indoleamine 2,3-dioxygenase (IDO) as well as release of cytokines was significantly enhanced and upon treatment with propolis extracts all these effects were dose-dependently suppressed. Results show an immunomodulatory effect of propolis extracts which includes down-regulation of IDO activity. IDO enzyme is considered to play an important role in the development of immunodeficiency and neuropsychiatric symptoms in patient with chronic inflammation. The suppression of tryptophan degradation by propolis extracts may therefore be related with some of its beneficial health properties in humans.

Bee and bee products allergy in Turkish beekeepers: determination of risk factors for systemic reactions

BACKGROUND The prevalence of allergic reactions due to bee stings in beekeepers varies in different regions of the world. The aim of this study was to evaluate the characteristics of sting reactions and the risk factors for developing systemic reactions in Turkish beekeepers. METHODS A self-administered questionnaire was distributed to 1250 beekeepers to be completed in seven different cities of Turkey. A total of 494 (39.6 %) questionnaires were returned. RESULTS There were 444 subjects (89.9 %) with a history of sting exposure in the previous 12 months. Systemic reactions were present in 29 subjects (6.5 %) and nine (2 %) reactions were anaphylactic. Fifty-five percent of beekeepers reported more than 100 bee stings in the previous year. When systemic reactions were controlled by age and duration of beekeeping in a logistic regression model, seasonal rhinitis (OR: 4.4, 95 % CI: 1.2-11.5), perennial rhinitis (OR: 4.6, 95 % CI: 1.2-18.2), food allergy (OR:7.0, 95 % CI: 2.0-25.0), physician-diagnosed asthma (OR: 8.0, 95 % CI: 2.5-25.6), having an atopic disease of any type (OR: 3.3, 95 % CI: 1.2-8.7) and having two or more atopic diseases (OR: 10.9, 95 % CI: 3.5-33.8) were significantly associated with systemic reactions due to bee sting in the previous 12 months. CONCLUSION The incidence of systemic reactions in Turkish beekeepers is low, which might be due to the protective effect of a high frequency of bee stings. The risk of systemic reactions increases approximately three-fold when one atopic disease is present and eleven-fold when two or more concurrent atopic diseases are present with respect to no atopic disease.

Evaluation on scolicidal efficacy of propolis.

Background: Propolis is a resinous material collected by bees from various plants. It has antimicrobial, antioxidative, immunostimulative, and regenerative properties. We determined the scolicidal effect of propolis in different concentrations and various exposure times. Materials and Methods: Tubes containing Echinococcus granulosus protoscoleces were supplementedwith different concentrations of ethyl alcohol extract of propolis. At the end of the incubation times, viabilityof protoscoleces was assessed by trypan blue exclusion test. We also applied 5 ml of 1 µg/ml propolis intraperitoneally for determination of side effects and mortality rates. Results: We determined that 1 µg/ml concentration of propolis killed all of the protoscoleces at the end of the 3rd minute. In the in vivo part of the study, intraperitoneal application of propolis did not cause any side effects or mortality. Conclusion: We concluded that this natural agent can be used as a potent scolicidal agent after studies which will determine in vivo efficacy and the effects on liver and biliary tree when injected directly into the common bile duct.

Effects of Manisa propolis on telomerase activity in leukemia cells obtained from the bone marrow of leukemia patients

Propolis is a resinous material collected by honeybees and obtained from beehives that has anticancer effects by inducing apoptosis. The aim of this study is to investigate the effect of propolis on human telomerase reverse transcriptase (hTERT) in the leukemia cells obtained from leukemia patients. Four different bone marrow cell cultures from each of four leukemia cases were prepared. The 60 ng/ml, 30 ng/ml and 15 ng/ml working concentrations of propolis were administered to three cultures of each patient, while one culture contained only culture medium. hTERT mRNA expression levels of cells were detected at 24 h, 48 h and 72 h using the LightCycler 2.0 instrument. A significant decrease in hTERT expression levels was observed in the 60 ng/ml concentration of propolis. In conclusion,Manisa propolis may also have a potential effect on the expression of hTERT in leukemia—particularly owing to its constituent chrysin.