Remziye Aysun Kepekci

Protective effect of Spirulina platensis enriched in phenolic compounds against hepatotoxicity induced by CCl4

Phenolic compounds make up the major secondary metabolites with high pharmaceutical potential. Microalgae were reported to contain low amounts of phenolic compounds. The present study aimed to investigate the hepatoprotective potential of biomass of Spirulina platensis enriched in phenolic compounds. The protective effects of the biomass of S. platensis with low amounts of phenolics (SP1) and with high amounts of phenolics (SP2) against CCl4-induced acute hepatotoxicity were evaluated in rats. The increased levels of ALT, AST and MDA along with decreased activities of SOD and CAT were significantly (p<0.01) ameliorated by SP2. Histological examinations revealed that SP2 was more potent than SP1 in protecting the liver from toxic injury of CCl4 and preserving the hepatocyte ultrastructure. The lesions including necrosis, lymphocyte infiltration, ballooning degeneration and hepatocyte injury as irregular lamellar organisation, dilations in endoplasmic reticulums and the presence of great number of cytoplasmic vacuolization were healed by SP2.

Histopathological, Ultrastructural and Apoptotic Changes in Diabetic Rat Placenta

BACKGROUND The exchange of substances between mother and fetus via the placenta plays a vital role during development. A number of developmental disorders in the fetus and placenta are observed during diabetic pregnancies. Diabetes, together with placental apoptosis, can lead to developmental and functional disorders. AIMS Histological, ultrastructural and apoptotic changes were investigated in the placenta of streptozotocin (STZ) induced diabetic rats. STUDY DESIGN Animal experimentation. METHODS In this study, a total of 12 female Wistar Albino rats (control (n=6) and diabetic (n=6)) were used. Rats in the diabetic group, following the administration of a single dose of STZ, showed blood glucose levels higher than 200 mg/dL after 72 hours. When pregnancy was detected after the rats were bred, two pieces of placenta and the fetuses were collected on the 20(th) day of pregnancy by cesarean incision under ketamine/ xylazine anesthesia from in four rats from the control and diabetic groups. Placenta tissues were processed for light microscopy and transmission electron microscopy (TEM). Hematoxylin-eosin (HE) and periodic acid Schiff-diastase (PAS-D) staining for light microscopic and caspase-3 staining for immunohistochemical investigations were performed for each placenta. Electron microscopy was performed on thin sections contrasted with uranyl acetate and lead nitrate. RESULTS Weight gain in the placenta and fetuses of diabetic rats and thinning of the decidual layer, thickening of the hemal membrane, apoptotic bodies, congestion in intervillous spaces, increased PAS-D staining in decidual cells and caspase-3 immunoreactivity were observed in the diabetic group. After the ultrastructural examination, the apoptotic appearance of the nuclei of trophoblastic cells, edema and intracytoplasmic vacuolization, glycogen accumulation, dilation of the endoplasmic reticulum and myelin figures were observed. In addition, capillary basement membrane thickening, capillary endothelial cells chromatin condensation in the nucleus and corrugation of the nucleus were found. CONCLUSION Diabetes causes histomorphometric, ultrastructural and apoptotic changes in rat placenta.

Biosorption of Food Green 3 by a novel green generation composite biosorbent from aqueous environment

ABSTRACT A green type composite biosorbent composed of pine, oak, hornbeam, and fir sawdust biomasses modified with cetyltrimethylammonium bromide (CTAB) was first used for biosorption of an unsafe synthetic food dye, Food Green 3 from liquid medium in this study. Batch studies were carried by observing the effects of pH, dye concentration, biosorbent amount, and contact time. The equilibrium data were analyzed using Freundlich, Langmuir, and Dubinin–Radushkevich equations. Freundlich model gave a better conformity than other equations. The maximum dye removal potential of biosorbent was found to be 36.6 mg/g based on Langmuir isotherm. The pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models were applied to clarify the process kinetics of biosorption. The mechanism studies suggested the biosorption process obeying Elovich kinetics and involving pore diffusion. The estimated values of biosorption free energy from Dubinin–Radushkevich isotherm (E value <8 kJ/mol) and thermodynamic studies (0 < ΔG° < −20 kJ/mol) implied a spontaneous, feasible, and physical process. Hence, this investigation suggested that the CTAB modified mix sawdust biomass could be a promising biosorbent for biosorption of such problematic dyes from impacted media.

Exploration of biosorption potential of forest industry by-product for removal of reactive dye from aqueous solution

Natural sawdust of Calabrian pine was explored as low-cost industrial by-product for a hetero-bireactive dye removal from aqueous solution in this study. Batch experiments were carried out to investigate the effects of contact time and dye concentration on biosorption efficiency. Maximum biosorption amounts were achieved almost in the 20-30 min of contact for the studied dye range (50-200 mg l-1). An increase in the dye concentration resulted in decrease in the percent dye removal and increase in the biosorption capacity of biosorbent. Different kinetic and isotherm models were used to examine the biosorption experimental data for elucidating the dye removal mechanism. The equilibrium data were best represented by Freundlich isotherm model confirming multilayer coverage. The kinetics of dye biosorption best obeyed the pseudo-secondorder equation. The negative value of standard Gibbs free energy change (-3.61 kJ mol-1) indicated that physical forces were involved in the spontaneous dye biosorption. Thus, the sawdust as a possible non-conventional biosorbent presented an interesting option for bioremediation of contaminated environments by such unsafe dyes.

Assessment of antioxidant activity and phycocyanin release of Spirulina loaded poly(ε-caprolactone) electrospun nanofibers

Abstract PCL with biodegradable property and Spirulina with various biological activities offer good alternative ingredients for the fabrication of functional nanofibers in tissue engineering. The aim of the study is to obtain PCL/Spirulina nanofibers with low diameters and to determine their wettability, antioxidant activity, and phycocyanin release to evaluate their potential as bioactive scaffolds in different applications. PCL/acetic acid/pyridine solutions with three different Spirulina concentrations were electrospun and the obtained nanofibers were investigated. The thinnest PCL/Spirulina nanofibers (117.20 nm) were obtained at 1.5% Spirulina concentration. Although PCL nanofibers with 6% Spirulina concentration showed the highest antioxidant activity and amount of phycocyanin released, PCL nanofibers with 3% Spirulina concentration having similar in vitro results showed superiority when considering the diameter and uniformity of the nanofibers and the cost of the material. The PCL/Spirulina nanofibers with small diameters and antioxidant activity could be regarded as potential extracellular matrix material for tissue engineering.

A promising biosorbent for biosorption of a model hetero-bireactive dye from aqueous medium

In this study, residual shell biomass of Corylus avellana L. was used as potential biosorbent for biosorption of a model industrial hetero-bireactive dye. The biosorbent was characterized by FTIR and SEM. The batch biosorption studies were performed as a function of dye concentration and contact time. The biosorption of dye was found to be very quick. Various kinetic and isotherm models were used to evaluate the obtained experimental data. The biosorption kinetic was best represented by the pseudo-second-order model while the biosorption equilibrium was best described by Langmuir model. The maximum dye biosorption capacity of biosorbent based on Langmuir isotherm was obtained as 74.527 mg g-1. These results showed that the use of such plant waste biomass in biosorption system could be a feasible method for the removal of such recalcitrant dye from industrial effluents to reduce operating costs.