Gamze Yildiz

Anti-hyperglycemic and antigenotoxic potential of Ulva rigida ethanolic extract in the experimental diabetes mellitus

An increased reactive oxygen species (ROS) and insufficient antioxidant activity is known in diabetes mellitus (DM). Antioxidant compounds in the human foods or supplementary diets can be used to counteract several diseases. The analysis of micronuclei (MN) is a cytogenetic technique used to show chromosomal damage caused by clastogenic affects. The present study was designed to evaluate: (i) the effects of diabetes mellitus on bone marrow MN frequency, (ii) the effect of oral administration of Ulva rigida ethanolic extract (URE) on MN frequency produced by DM, and (iii) some hematological values in normal and streptozotocin-induced diabetic rats. Daily fluid and food consumptions, weekly body weights, blood glucose concentrations and serum insulin levels were also examined in the study groups during the two different administration periods. The blood glucose concentration and MN frequency have been significantly increased in diabetic rats compared with the normal rats (p<0.0001). Especially, URE-30d group treatment in diabetic rats was significantly decreased blood glucose concentrations and MN frequency. This is the first report on the anti-hyperglycemic, anti-oxidative and genotoxic/antigenotoxic capacity of U. rigida in vivo. Our results suggest that URE shows strong anti-hyperglycemic and antigenotoxic effect on the genotoxicity produced by DM in rats.

Evaluation of anti-oxidative, genotoxic and antigenotoxic potency of Codium tomentosum Stackhouse ethanolic extract in human lymphocytes in vitro.

The genome is constantly exposed to agents, both exogenous and endogenous, that damage DNA. Consequently, it is very important that determination of this agents and the protective agents. In this work, we evaluated the antigenotoxic/antimutagenic activity of the crude ethanolic extracts of Codium tomentosum Stackhouse (Chlorophyceae) (CTE), collected from The Coast of South East Marmara Sea, in human lymphocytes culture in vitro against genotoxic/mutagenic agents MMC, EMS and H(2)O(2) by using chromosome aberration (CA), sister chromatid exchange (SCE) and micronuclei (MN) assays as experimental endpoints. Also, in the present study, we determined total phenolic content and total antioxidant capacity (in soluble lipid and water). In addition, total protein, total carbohydrate, vitamins (A, C and E) and pigments (chlorophyll a, chlorophyll b and carotene) contents were also determined. Results of CA, SCE and MN tests show that CTEs have not shown genotoxic effect. In CTE plus MMC-, EMS- or H(2)O(2)- treated cultures, CA, SCE and MN frequency which induced by MMC, EMS or H(2)O(2) has been decreased significantly (p<0.05-0.001). This is the first report on genotoxicity/antigenotoxicity and anti-oxidative capacity of Codium tomentosum. Our results have clearly shown that CTE has strong anti-oxidative and antigenotoxic effect.

In vitro antigenotoxicity of Ulva rigida C. Agardh (Chlorophyceae) extract against induction of chromosome aberration, sister chromatid exchange and micronuclei by mutagenic agent MMC.

OBJECTIVE To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C (MMC). METHODS Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro. RESULTS The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 microg/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC (P < 0.0001). CONCLUSION Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.

Determination of the Anti-Oxidative Capacity and Bioactive Compounds in Green Seaweed Ulva rigida C. Agardh

There is an increasing demand for natural antioxidant molecules in order to replace the synthetic additives in the food industry. Therefore, Ulva rigida C. Agardh was analyzed to determine its bioactive components, including the total phenolic content, antioxidant capacity (lipid and water-soluble), vitamins (A, E, and C), protein, carbohydrate, and pigments. As a result, Ulva rigida showed a high total phenolic, vitamin E, and total carotene content. Hence, U. rigida could be considered as a plant possessing natural antioxidant molecules and might be useful for the food industry. U. rigida can also be used for curing diseases arising from oxidative deterioration.

Determination of the Phenolic Compounds and Antioxidative Capacity in Red Algae Gracilaria bursa-pastoris

There is an increasing demand for natural antioxidant molecules in order to replace the synthetic additives in the food industry. Gracilaria bursa-pastoris (Gmelin) Silva was analyzed to determine its bioactive components including; the total phenolic content, total antioxidant capacity (lipid and water-soluble), vitamins (A, E and C), total protein and total carbohydrate content. In addition, the bioactive components of Gracilaria bursa-pastoris were compared with some plants and seaweeds having antioxidant capacity. This study showed that Gracilaria bursa-pastoris contained a high total phenolic content, vitamin E, vitamin C and the antioxidant capacity. Gracilaria bursa-pastoris can be utilized as a source of natural antioxidant molecules and could be useful for food industry.

Ultraviolet radiation modulates the physiological responses of the calcified rhodophyte Corallina officinalis to elevated CO2

Abstract Ocean acidification reduces the concentration of carbonate ions and increases those of bicarbonate ions in seawater compared with the present oceanic conditions. This altered composition of inorganic carbon species may, by interacting with ultraviolet radiation (UVR), affect the physiology of macroalgal species. However, very little is known about how calcareous algae respond to UVR and ocean acidification. Therefore, we conducted an experiment to determine the effects of UVR and ocean acidification on the calcified rhodophyte Corallina officinalis using CO2-enriched cultures with and without UVR exposure. Low pH increased the relative electron transport rates (rETR) but decreased the CaCO3 content and had a miniscule effect on growth. However, UVA (4.25 W m-2) and a moderate level of UVB (0.5 W m-2) increased the rETR and growth rates in C. officinalis, and there was a significant interactive effect of pH and UVR on UVR-absorbing compound concentrations. Thus, at low irradiance, pH and UVR interact in a way that affects the multiple physiological responses of C. officinalis differently. In particular, changes in the skeletal content induced by low pH may affect how C. officinalis absorbs and uses light. Therefore, the light quality used in ocean acidification experiments will affect the predictions of how calcified macroalgae will respond to elevated CO2.

The effects of elevated-CO2 on physiological performance of Bryopsis plumosa

An increase in the level of atmospheric carbon dioxide (CO2) and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower pH in seawater and may affect the physiology of seaweed species. Accordingly, the main goal of the current study was to determine the physiological responses of Bryopsis plumosa to elevated-CO2. The results indicated that photosynthesis of B. plumosa was insignificantly affected to elevated-CO2, but photosynthetic pigment contents and phenolics were significantly decreased. The results obtained from the research reveal that B. plumosa may become physiologically advanced when exposed to CO2-induced ocean acidification. In particular, B. plumosa may be more able to compete with calcifying algae when it will become future predicted CO2 scenario.

Protective and antigenotoxic effect of Ulva rigida C. Agardh in experimental hypothyroid

The presence of chromosomal damage in bone marrow cells affected by several diseases such as thyroid, cancer etc., was detected by the micronucleus (MN) assay. The present study was designed to evaluate: i) volatile components of Ulva rigida, ii) effects of hypothyroidism on bone marrow MN frequency, iii) effects of oral administration of Ulva rigida ethanolic extract (URE) on MN frequency produced by hypothyroidism, and iv) thyroid hormone levels in normal and 6-n-Propylthiouracil (PTU)-induced hypothyroid rats. The volatile components of Ulva rigida was studied using a direct thermal desorption (DTD) technique with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOF/MS). URE administration was of no significant impact on thyroid hormone levels in control group, while PTU administration decreased thyroid hormone levels compared to control group (p < 0.001). Moreover, URE supplementation resulted in a significant decrease in MN frequency in each thyroid group (p < 0.0001). This is the first in vivo study that shows the strong antigenotoxic and protective effect of URE against the genotoxicity produced by hypothyroidism.

Physiological Responses of the Mediterranean Subtidal Alga Peyssonnelia squamaria to Elevated CO2

The ecological consequences of ocean acidification are unclear due to varying physiological properties of macroalgae and species-specific responses. Therefore, in the present study, we used a laboratory culture experiment to analyse the eco-physiological responses of the Mediterranean subtidal red alga Peyssonnelia squamaria to CO2-induced lower pH. Our results showed an increase in the photosynthetic performance and growth rate of P. squamaria, despite the reduction in CaCO3 content in the low pH treatment. According to our results, we believe that samples exposed to elevated CO2 could be regulated own nitrogen metabolism to support increased growth rate and it may be down-regulated nitrate uptake. As a result, we hypothesize that P. squamaria may benefit from ocean acidification.