Kiliçgün, Hasan; Arda, Nazli; Uçar, Evren

Background: Pomegranate (Punica granatum L.) is commonly consumed as fresh fruit and fruit juice. It is also used in the production of jam, wine, food coloring agent, and flavor enhancer. Objective: The aim of this study was to identify the possible longevity, fertility and growth promoting properties of different ethanolic extract concentrations of pomegranate in Caenorhabditis elegans, which is increasingly popular and has proven to be a very useful experimental model organism for aging studies as well as for testing antioxidants and other compounds for effects on longevity. Materials and Methods: In this study, five experimental groups (20, 10, 5, 2.5 and 1.25 mg pomegranate extract/mL and one control group) were used to determine the most effective dose of pomegranate in terms of longevity, fertility and growth parameters. Results: It was seen that, pomegranate extracts up to the concentration of 5 mg/mL, had the potential to promote for the longevity, formation of new generations, fertility of new generations and growth properties of C. elegans although higher concentrations significantly reduced these parameters. Conclusion: these findings indicated that pomegranate could be used as a supplement to enhance longevity, fertility and growth rate for the other living organisms and human beings, but the dose should be carefully adjusted to avoid adverse effects.

Kiliçgün, Hasan; Göksen, Gülden

Background: The beneficial effects of antioxidants in plants are mainly extrapolated from in vitro studies or short-term dietary supplementation studies. Due to cost and duration, relatively little is known about whether dietary antioxidants are beneficial in whole animals′ life span or not. Materials and Methods: To address this question, under heat stress (35°C), Hypericum perforatum was extracted with petroleum ether and the nematodes Caenorhabditis elegans exposed to three different extract concentrations (1mg/mL, 0.1mg/mL, 0.01mg/mL) of H. perforatum. Results: We report that Hypericum perforatum extracts did not increase life span and slow aging related increase in C. elegans. Moreover, one fraction (1mg/mL) increased declines of C. elegans life span and thermotolerance. Conclusion: Given this mounting evidence for life span role of H. perforatum in the presence of heat stress in vivo, the question whether H. perforatum acts as a prooxidant or an antioxidant in vivo under heat stress arises.

Kilicgun, Hasan; Altiner, Dehen

Rosa canina L. is a member of Rosaceae family, which is well-known for its high phenolic contents. These compounds are known to possess antioxidant, antimutagenic and anticarcinogenic effects. However, they have yet to pass controlled clinical trials for efficacy, and their potential for prooxidant activity is an understudied field of research. In order to estimate the correlations between phenolic contents and antioxidant/proxidant effect mechanisms, different concentrations of R. canina fruit extracts were examined in this study. R. canina showed antioxidant activities at all concentrations with respect to the reducing power, hydrogen peroxide scavenging activity and superoxide anion radical scavenging (O2-) activity assays, whereas a negative correlation was observed with the metal ion chelating activity and free radical scavenging activity [1,1-diphenyl-2-picryl-hydrazil (DPPH) % inhibition] assays at higher concentrations with the phenolic content of R. canina. These results suggest that R. canina may act not only as an antioxidant, but also as a prooxidant with the effects depending on its concentrations.

Hasan, Kiliçgün; Dehen, Altiner

In this study we aimed to determine the antioxidant effects of Cocoa (Theobroma cacao L.), which is commonly used in both chocolate and cocoa drinks all over the world, on lipid peroxidation, alanine transaminase (ALT), aspartate transaminase (AST), glutathione (GSH) and protein oxidation levels in carbon tetrachloride (CCl 4) treated for male Wistar rats. Two control groups and one treatment group of rats were formed. The control groups were nourished with a standard diet, while the Cocoa group was nourished with standard diet which was enriched with % 6 by weight dried Cocoa powder. After three months, a single dose of carbon tetrachloride (CCl 4) was performed in Control II (CCl 4) and Cocoa groups (1ml/kg, as 20% in olive oil) intraperitoneally and single dose of olive oil was administered (1ml/kg,i.p.) in the same way as rats in Control I group. They were sacrificed two hours later. Lipid peroxide levels in liver, protein oxidation in liver, glutathione levels in liver, ALT and AST in plasma were measured. Cocoa decreased liver lipid peroxide, liver glutathione levels and plasma ALT and AST activities previously increased by CCl 4 treatment, to the Control I levels The protein oxidation levels in the rats in the Cocoa group compared with the rats in CCl 4 treated control group were found to have significantly lessened. These findings suggest that cocoa has strong antioxidant activity because of the fact that cocoa inhibits liver injury.