eda çandöken - Academia.edu (original) (raw)

Papers by eda çandöken

Journal of Faculty Pharmacy of Istanbul University, 2012

SUMMARY A new and rapid affinity chromatography method based on cyanogen bromide (CNBr)-activated... more SUMMARY A new and rapid affinity chromatography method based on cyanogen bromide (CNBr)-activated Sepharose 4B bound-ovalbumin is presented for the purification of the main lectin present in Aloe vera (L.) Burm. fil. The lectin was purified 60 fold to apparent homogeneity in native polyacrylamide disc gel electrophoresis (PAGE) showing an apparent molecular weight of 45000 kDa. The fact that sodium dodecyl sulfate (SDS)-PAGE gave a subunit molecular weight of 14 400 kDa tends to propose that the lectin is composed of three subunits and thus is in agreement with Aloctin I previously partially purified and characterized by us. The lectin did not exhibit antioxidant effect as assessed by the DPPH· radical-scavenging assay. OZET Aloe vera (L.) Burm. fil. lektinin saflastirilmasi icin, yeni ve hizli bir kromatografi yontemi olan, ovalbumin bagli-siyanojen bromur (CNBr) ile aktive edilmis Sefaroz 4B, afinite kromatografisi tanitilmaktadir. Lektin, kromatografi sonucunda 60 kez saflastiril...

Background: The present study was designed to evaluate the mechanism of cytotoxic effects of AE r... more Background: The present study was designed to evaluate the mechanism of cytotoxic effects of AE relative to Aloe vera gel extract (AVG) on chronic myelogenous leukemia K562 and Burkitt’s lymphoma P3HR-1 cell lines. Methods: Cytotoxicity tests were assessed by tetrazolium bromide (MTT) assay. Annexin V-FITC/PI labelling was used for apoptosis/necrosis evaluation and western blotting for apoptotic molecules measurement. Results: It was shown that, AE has cytotoxic activity againts K562 and P3HR-1 cells with an IC50 value of 60.9 µM and 28 µM, respectively. AVG was found cytotoxic on K562 cells with an IC50 value of 243.2 µg/ml and ineffective on P3HR-1 cells. The ratio of apoptotic cells (46.7%) was high in only K562 cells after AVG treatment. The percentage of apoptotic cells (K562=34.1, P3HR-1=38.8) was higher than necrotic cells (K562=11.9, P3HR-1=16.6) after AE treatment. The main apoptosis pathway in both cell lines was found to be through caspase-3 and caspase-9 activations afte...

Journal of Faculty Pharmacy of Istanbul University, 2016

Abstract: Aloe vera, sometimes referred as a “miraculous” or “wonder” plant, has been used by man... more Abstract: Aloe vera, sometimes referred as a “miraculous” or “wonder” plant, has been used by mankind for centuries for the treatment of different disorders due to the inner gel of its succulent leaves. Medical usage and applications of the main species, namely Aloe vera (L.) Burm. f. are mainly attributed to immunomodulatory or antioxidant activities. Our work on A. vera has begun with the separation of anthraquinones and continued with the purification and characterization of the lectins. In another study, hypoglycemic effect of A. vera leaf extracts was assayed in vivo, followed by the effect of the extracts on several tissues in diabetic rats. A. vera has shown a significant prophylactic effect on Ehrlich ascites tumour cells when given before tumour inoculation in mice. This effect was also seen with the purified lectin and attributed to the immunomodulatory effect of the plant. Assuming that its benefit could also be attributed to the antioxidant activity, the antioxidant pote...

Istanbul Journal of Pharmacy, 2018

Known for centuries as a "wonder" plant, Aloe vera (L.) Burm. f. has many biological and pharmaco... more Known for centuries as a "wonder" plant, Aloe vera (L.) Burm. f. has many biological and pharmacological activities. These effects are due to the variety of the chemical compounds including anthraquinones, glycoproteins, polysaccharides, vitamins and enzymes contained (Choi and Chung 2003; Du Plessis and Hamman 2014; Akev et al. 2015; Shrestha et al. 2015). Many of the medicinal effects have also been attributed to the immunomodulatory properties of the inner gel (Im et al. 2010), but it is also believed that synergistic action of the compounds contained in the whole leaf extracts is responsible for the multiple and diverse beneficial properties of the plant (Eshun and He 2004). The mucilageneous gel part of A. vera is used commercially as a softener in various cosmetic preparations, soaps and shampoos due to its glycoprotein content. The first known effects of A. vera after its cathartic activity, is the wound and burn healing effect of the leaves gel portion, widely supported in scientific literature (Capasso et al. 1998; Chithra et al. 1998; Heggers et al. 1995). Because of this effect, the gel is also added to many preparations used for skin treatment. Antitumor and cytotoxic potential of A. vera extracts continues to be the interest of scientific research from 1980's (Winters et al. 1981; Tsuda et al. 1993; Corsi et al. 1998) until recent years (Naveena Bharath and Selvasubramanian 2011; Du Plessis and Hamman 2014). In a research undertaken in our laboratory, A. vera leaf skin aqueous extract was proved to be effective as prophylactic against Ehrlich ascites tumours in vivo (Akev et al. 2007). The Food and Drug Administration of the USA has approved the developmental study of A. vera for the treatment of cancer and AIDS (Nandal and Bhardwaj 2012). Antitumor effect of aloe emodin (AE), the major anthraquinone derivative of A. vera, was reported in recent years (Cárdenas et al. 2006; Lee et al. 2006; Lin et al. 2006) and attention has been given recently to the possibility of utilizing AE as a chemothera

Asian Pacific Journal of Cancer Prevention, 2020

The multiple biological effects of the "wonder plant" Aloe vera (L.) Burm. f. (Xanthorraceae, for... more The multiple biological effects of the "wonder plant" Aloe vera (L.) Burm. f. (Xanthorraceae, formerly Aloaceae and Liliaceae) were proved and reviewed by scientific research (Akev et al., 2015). Several in vivo studies were conducted from 1980's to date with A. vera leaf extracts regarding their antitumour effects (Winters et al., 1981; Gribel and Pashinskiĭ, 1986; Akev et al., 2007a). Aloe emodin (AE) is an anthraquinone glycoside purified from A. vera. In addition to its well established laxative effect, AE have been reported to exhibit antiviral, antimicrobial, hepatoprotective and anticancer properties. Considerable attention has been given recently to the possibility of utilizing AE as a chemotherapeutic drug for the treatment of various types of cancers (Yordanova and Koprinarova, 2014). Lectins are proteins or glycoproteins that bind to specific sugar residues on cell surfaces (Sharon and Lis, 1972). Lectins play multiple roles in inter-and intra-cellular

Balkan Medical Journal, 2018

Background: Flavonoids are natural compounds with antioxidant, anticarcinogenic, and anti-inflamm... more Background: Flavonoids are natural compounds with antioxidant, anticarcinogenic, and anti-inflammatory effects. Aim: This study aimed to determine the cytotoxic effects of flavonoids and drug resistance related to P-gp on K562 human chronic myeloid leukemia cells. We also aimed to evaluate the therapeutic potential of imatinib and flavonoid combinations. Study Design: Cell culture study. Materials and Methods: In this study, K562 cells were treated with apigenin, luteolin, 5-desmethyl sinensetin and the anticancer drug imatinib mesylate. The effect of flavonoids on K562 cell proliferation was detected using the MTT assay. Concentrations of apigenin, luteolin, and 5-desmethyl sinensetin ranging from 25 to 200 µM and of imatinib from 5 to 50 µM administered for 72 h were studied. Apoptosis/necrosis and P-gp activity were measured using flow cytometry. The combined effects of different concentrations of flavonoids with imatinib were evaluated according to combination index values calculated using CompuSyn software. Results: In our study, the IC50 values for apigenin, luteolin, and 5-desmethyl sinensetin were found to be 140 μM, 100 μM, and >200 μM, respectively. Luteolin (100 μM) had the highest cytotoxic activity of these flavonoids. These results were statistically significant (p < 0.05). Among the flavonoids studied, the combination of luteolin and imatinib was the most effective and is therefore recommended for its cytotoxic activity in the K562 cell line. After 72 h of incubation at their respective IC50 concentrations, all flavonoids were associated with an apoptosis rate of approximately 50%. P-gp activity was increased in all groups. Combination treatment may provide better outcomes in terms of cytotoxicity and thus reduce the dosages of imatinib used. Conclusion: Although imatinib and other tyrosine kinase inhibitors are used widely in the treatment of chronic myeloid leukemia, the search continues for newer, more effective drugs. An advantage of using drug combinations is that it would allow patients to be given lower doses of anticancer drugs, because each drug can act through different mechanisms. Finally, the combination of these flavonoids and imatinib mesylate was able to enhance the cytotoxic effect; however, the antagonistic effect should be considered in their combined use on K562 cells.

Oxidative Medicine and Cellular Longevity, 2009

In order to demonstrate whether the known biological effects ofAloe vera(L.) Burm. fil. could cor... more In order to demonstrate whether the known biological effects ofAloe vera(L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract fromA. veraleaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, β-carotene and α-tocopherol. The extract exhibited inhibitory capacity against Fe3+/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH•, ABTS•+and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects ofAloe veracould be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.

Journal of Faculty Pharmacy of Istanbul University, 2012

SUMMARY A new and rapid affinity chromatography method based on cyanogen bromide (CNBr)-activated... more SUMMARY A new and rapid affinity chromatography method based on cyanogen bromide (CNBr)-activated Sepharose 4B bound-ovalbumin is presented for the purification of the main lectin present in Aloe vera (L.) Burm. fil. The lectin was purified 60 fold to apparent homogeneity in native polyacrylamide disc gel electrophoresis (PAGE) showing an apparent molecular weight of 45000 kDa. The fact that sodium dodecyl sulfate (SDS)-PAGE gave a subunit molecular weight of 14 400 kDa tends to propose that the lectin is composed of three subunits and thus is in agreement with Aloctin I previously partially purified and characterized by us. The lectin did not exhibit antioxidant effect as assessed by the DPPH· radical-scavenging assay. OZET Aloe vera (L.) Burm. fil. lektinin saflastirilmasi icin, yeni ve hizli bir kromatografi yontemi olan, ovalbumin bagli-siyanojen bromur (CNBr) ile aktive edilmis Sefaroz 4B, afinite kromatografisi tanitilmaktadir. Lektin, kromatografi sonucunda 60 kez saflastiril...

Background: The present study was designed to evaluate the mechanism of cytotoxic effects of AE r... more Background: The present study was designed to evaluate the mechanism of cytotoxic effects of AE relative to Aloe vera gel extract (AVG) on chronic myelogenous leukemia K562 and Burkitt’s lymphoma P3HR-1 cell lines. Methods: Cytotoxicity tests were assessed by tetrazolium bromide (MTT) assay. Annexin V-FITC/PI labelling was used for apoptosis/necrosis evaluation and western blotting for apoptotic molecules measurement. Results: It was shown that, AE has cytotoxic activity againts K562 and P3HR-1 cells with an IC50 value of 60.9 µM and 28 µM, respectively. AVG was found cytotoxic on K562 cells with an IC50 value of 243.2 µg/ml and ineffective on P3HR-1 cells. The ratio of apoptotic cells (46.7%) was high in only K562 cells after AVG treatment. The percentage of apoptotic cells (K562=34.1, P3HR-1=38.8) was higher than necrotic cells (K562=11.9, P3HR-1=16.6) after AE treatment. The main apoptosis pathway in both cell lines was found to be through caspase-3 and caspase-9 activations afte...

Journal of Faculty Pharmacy of Istanbul University, 2016

Abstract: Aloe vera, sometimes referred as a “miraculous” or “wonder” plant, has been used by man... more Abstract: Aloe vera, sometimes referred as a “miraculous” or “wonder” plant, has been used by mankind for centuries for the treatment of different disorders due to the inner gel of its succulent leaves. Medical usage and applications of the main species, namely Aloe vera (L.) Burm. f. are mainly attributed to immunomodulatory or antioxidant activities. Our work on A. vera has begun with the separation of anthraquinones and continued with the purification and characterization of the lectins. In another study, hypoglycemic effect of A. vera leaf extracts was assayed in vivo, followed by the effect of the extracts on several tissues in diabetic rats. A. vera has shown a significant prophylactic effect on Ehrlich ascites tumour cells when given before tumour inoculation in mice. This effect was also seen with the purified lectin and attributed to the immunomodulatory effect of the plant. Assuming that its benefit could also be attributed to the antioxidant activity, the antioxidant pote...

Istanbul Journal of Pharmacy, 2018

Known for centuries as a "wonder" plant, Aloe vera (L.) Burm. f. has many biological and pharmaco... more Known for centuries as a "wonder" plant, Aloe vera (L.) Burm. f. has many biological and pharmacological activities. These effects are due to the variety of the chemical compounds including anthraquinones, glycoproteins, polysaccharides, vitamins and enzymes contained (Choi and Chung 2003; Du Plessis and Hamman 2014; Akev et al. 2015; Shrestha et al. 2015). Many of the medicinal effects have also been attributed to the immunomodulatory properties of the inner gel (Im et al. 2010), but it is also believed that synergistic action of the compounds contained in the whole leaf extracts is responsible for the multiple and diverse beneficial properties of the plant (Eshun and He 2004). The mucilageneous gel part of A. vera is used commercially as a softener in various cosmetic preparations, soaps and shampoos due to its glycoprotein content. The first known effects of A. vera after its cathartic activity, is the wound and burn healing effect of the leaves gel portion, widely supported in scientific literature (Capasso et al. 1998; Chithra et al. 1998; Heggers et al. 1995). Because of this effect, the gel is also added to many preparations used for skin treatment. Antitumor and cytotoxic potential of A. vera extracts continues to be the interest of scientific research from 1980's (Winters et al. 1981; Tsuda et al. 1993; Corsi et al. 1998) until recent years (Naveena Bharath and Selvasubramanian 2011; Du Plessis and Hamman 2014). In a research undertaken in our laboratory, A. vera leaf skin aqueous extract was proved to be effective as prophylactic against Ehrlich ascites tumours in vivo (Akev et al. 2007). The Food and Drug Administration of the USA has approved the developmental study of A. vera for the treatment of cancer and AIDS (Nandal and Bhardwaj 2012). Antitumor effect of aloe emodin (AE), the major anthraquinone derivative of A. vera, was reported in recent years (Cárdenas et al. 2006; Lee et al. 2006; Lin et al. 2006) and attention has been given recently to the possibility of utilizing AE as a chemothera

Asian Pacific Journal of Cancer Prevention, 2020

The multiple biological effects of the "wonder plant" Aloe vera (L.) Burm. f. (Xanthorraceae, for... more The multiple biological effects of the "wonder plant" Aloe vera (L.) Burm. f. (Xanthorraceae, formerly Aloaceae and Liliaceae) were proved and reviewed by scientific research (Akev et al., 2015). Several in vivo studies were conducted from 1980's to date with A. vera leaf extracts regarding their antitumour effects (Winters et al., 1981; Gribel and Pashinskiĭ, 1986; Akev et al., 2007a). Aloe emodin (AE) is an anthraquinone glycoside purified from A. vera. In addition to its well established laxative effect, AE have been reported to exhibit antiviral, antimicrobial, hepatoprotective and anticancer properties. Considerable attention has been given recently to the possibility of utilizing AE as a chemotherapeutic drug for the treatment of various types of cancers (Yordanova and Koprinarova, 2014). Lectins are proteins or glycoproteins that bind to specific sugar residues on cell surfaces (Sharon and Lis, 1972). Lectins play multiple roles in inter-and intra-cellular

Balkan Medical Journal, 2018

Background: Flavonoids are natural compounds with antioxidant, anticarcinogenic, and anti-inflamm... more Background: Flavonoids are natural compounds with antioxidant, anticarcinogenic, and anti-inflammatory effects. Aim: This study aimed to determine the cytotoxic effects of flavonoids and drug resistance related to P-gp on K562 human chronic myeloid leukemia cells. We also aimed to evaluate the therapeutic potential of imatinib and flavonoid combinations. Study Design: Cell culture study. Materials and Methods: In this study, K562 cells were treated with apigenin, luteolin, 5-desmethyl sinensetin and the anticancer drug imatinib mesylate. The effect of flavonoids on K562 cell proliferation was detected using the MTT assay. Concentrations of apigenin, luteolin, and 5-desmethyl sinensetin ranging from 25 to 200 µM and of imatinib from 5 to 50 µM administered for 72 h were studied. Apoptosis/necrosis and P-gp activity were measured using flow cytometry. The combined effects of different concentrations of flavonoids with imatinib were evaluated according to combination index values calculated using CompuSyn software. Results: In our study, the IC50 values for apigenin, luteolin, and 5-desmethyl sinensetin were found to be 140 μM, 100 μM, and >200 μM, respectively. Luteolin (100 μM) had the highest cytotoxic activity of these flavonoids. These results were statistically significant (p < 0.05). Among the flavonoids studied, the combination of luteolin and imatinib was the most effective and is therefore recommended for its cytotoxic activity in the K562 cell line. After 72 h of incubation at their respective IC50 concentrations, all flavonoids were associated with an apoptosis rate of approximately 50%. P-gp activity was increased in all groups. Combination treatment may provide better outcomes in terms of cytotoxicity and thus reduce the dosages of imatinib used. Conclusion: Although imatinib and other tyrosine kinase inhibitors are used widely in the treatment of chronic myeloid leukemia, the search continues for newer, more effective drugs. An advantage of using drug combinations is that it would allow patients to be given lower doses of anticancer drugs, because each drug can act through different mechanisms. Finally, the combination of these flavonoids and imatinib mesylate was able to enhance the cytotoxic effect; however, the antagonistic effect should be considered in their combined use on K562 cells.

Oxidative Medicine and Cellular Longevity, 2009

In order to demonstrate whether the known biological effects ofAloe vera(L.) Burm. fil. could cor... more In order to demonstrate whether the known biological effects ofAloe vera(L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract fromA. veraleaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, β-carotene and α-tocopherol. The extract exhibited inhibitory capacity against Fe3+/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH•, ABTS•+and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects ofAloe veracould be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.