Zahide Esra Durak

Serum glutathione peroxidase, xanthine oxidase, and superoxide dismutase activities and malondialdehyde levels in patients with Parkinson's disease.

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Oxidative stress has been hypothesized to play a major role in the development of PD in various studies. This study assessed to investigate oxidative and anti-oxidative status in PD patients. We evaluated oxidant/antioxidant status by measuring serum malondialdehyde (MDA) levels, xanthine oxidase (XO) activities, and activities of antioxidant enzymes, namely, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). The study included 29 patients with PD and 32 healthy subjects as controls. Comparison of oxidative parameters in the patient and control groups revealed significantly higher GSH-Px and XO activities in the patient group. Serum MDA and SOD activities in PD patients were not significantly different from the controls. MDA was negatively correlated with duration of the PD and positively with age of onset. There was a negative correlation between SOD and Hoehn and Yahr (H&Y) stage. According to these results, we suggest that oxidative stress may contribute to the development of PD.

Serum oxidant and antioxidant status of patients with chronic tension-type headache: possible effects of medical treatment

Tension-type headache (TTH) is one of the most common and costly primary types of headache in clinical practice, with an unknown etiology. This study assessed to investigate oxidative and antioxidative status in patients with chronic tension-type headache (CTTH), and to evaluate possible effect of medical treatment. The study included 41 CTTH patients and 19 age- and sex-matched healthy subjects without headache as controls. The CTTH group comprised 20 patients receiving treatment and 21 untreated patients. We evaluated oxidant/antioxidant status by measuring serum malondialdehyde (MDA) levels and activities of antioxidant enzymes, namely glutathione peroxidase (GSH-Px) and catalase (CAT). Comparison of oxidative parameters in the patient and control groups revealed significantly lower CAT activities and higher MDA level and GSH-Px activities in the patient group. In the CTTH group, serum CAT activities were found to be significantly decreased in patient groups, while serum MDA levels and GSH-Px activities were found to be higher in the untreated CTTH patients. These findings suggest that oxidative stress is increased in the patients with CTTH, and medical treatment abolishes the stress in part. It has been concluded that antioxidant support might be helpful for the patients with CTTH to prevent oxidant stress and peroxidation damages further.

Oxidative and nitrosative stress in serum of patients with Parkinson’s disease

Parkinson’s disease (PD) is one of the common neurodegenerative disorders. Oxidative stress is considered as a contributing factor to the development of PD. The present study aims to investigate serum oxidative stress status in patients with PD. Oxidative stress was assessed by measuring serum nitric oxide levels, lipid hydroperoxide concentrations, and nitric oxide synthase activity. In addition, total serum antioxidant capacity (TAC) was evaluated using the serum 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) free-radical scavenging method in 32 patient with Parkinson’s disease and 32 control subjects. Our results indicated that serum nitric oxide and lipid hydroperoxide levels were significantly lower in patients with PD than controls. Moreover, nitric oxide levels were found to be negatively correlated with Unified Parkinson’s Disease Rating Scale (UPDRS). However, no statistical difference was observed in total serum antioxidant capacities and nitric oxide synthase activities between patients and controls. The present study indicates that although antioxidant capacity was not changed, lipid hydroperoxide (LPO) level was found decreased. This might show pre-oxidative process in these patients. In addition, decreased nitric oxide (NO) level and negative correlation observed between NO level and disease rating scale implicated a role for NO in the disease process.

Aqueous extract from taxus baccata inhibits adenosine deaminase activity significantly in cancerous and noncancerous human gastric and colon tissues

Objective: To investigate possible effects of aqueous taxus baccata extract on adenosine deaminase (ADA) activity in cancerous and noncancerous human tissues and to clarify mechanism(s) of its anticancer potential. Materials and Methods: Cancerous and noncancerous human gastric and colon tissues were used in the study. The extracts were prepared in distilled water. Before and after treatment with the extracts, ADA activities in the tissue homogenates were measured. Results: ADA activity was found to be higher in gastric tissue compared with colon tissue, but no differences were found between ADA activities of cancerous and noncancerous tissues for both as well. In the plant extract studies, it was found that taxus extract significantly inhibited ADA activity both in cancerous and noncancerous gastric and colon tissues. Conclusion: Our results suggest that aqueous extract from taxus baccata inhibits ADA activities in both gastric and colon tissues significantly. It is suggested that in addition to other proposed mechanisms, accumulated adenosine due to the inhibition of ADA enzyme might also play part in the anticancer properties of taxus species.

Effects of aqueous extract from Silybum marianum on adenosine deaminase activity in cancerous and noncancerous human gastric and colon tissues

Objective: Investigation of possible effects of Silybum marianum extract (SME) on adenosine deaminase (ADA) activity in cancerous and noncancerous human gastric and colon tissues to obtain information about possible mechanism of anticancer action of S. marianum. Materials and Methods: Cancerous and noncancerous human gastric and colon tissues removed from patients by surgical operations were used in the studies. The extract was prepared in distilled water. Before and after treatment with the extract, ADA activities in the samples were measured. Results: ADA activity was found to be lowered significantly in cancerous gastric tissues but not in noncancerous gastric tissues after treatment with the SME. In the colon tissues, ADA activities were however found to increase after the treatment of SME. Conclusion: Our results suggest that the aqueous extract from S. marianum inhibits ADA activity in cancerous gastric tissues significantly. It is suggested that in addition to other proposed mechanisms, accumulated adenosine due to the inhibition of ADA might also play a part in the anticancer properties of the S. marianum.

Effect of Static Magnetic Field on Oxidant/Antioxidant Parameters in Cancerous and Noncancerous Human Gastric Tissues

Aim. To investigate the effects of static magnetic field (SMF) on oxidant and antioxidant parameters of the cancerous and noncancerous human gastric tissues. Materials and Methods. Gastric tissues obtained from patients with gastric cancer were used in the study. SMF was created by using two static magnets. Before and after treatment with SMF, oxidant and antioxidant parameters were measured in the tissue samples. Results. In the cancerous tissue, superoxide dismutase (SOD) activity was found higher and malondialdehyde (MDA) level was found lower as compared with noncancerous tissue. SMF affects oxidant/antioxidant parameters differently in the cancerous and noncancerous tissues. In this regard, SMF causes increase in SOD activity and decrease in MDA level in the noncancerous tissue. However, it decreases SOD and glutathione peroxidase (GSH-Px) activities and increases MDA level and catalase (CAT) activity in the cancerous tissue. There were no differences between nitric oxide (NO) and nitric oxide synthase (NOS) parameters in or among the cancerous and noncancerous tissues. Conclusions. SMF accelerates peroxidation reactions possibly by suppressing SOD and GSH-Px enzymes in the cancerous gastric tissue. This event caused by SMF might play part in the death of cancer cells, which may be a good supportive vehicle for the cancer therapy.

High cholesterol diet leads to oxidant load and peroxidation in the rabbit kidney tissue.

OBJECTIVES The aim of this study was to investigate possible effects of high cholesterol diet on oxidant/antioxidant status in rabbit kidney tissues. BACKGROUND Although a number of experimental animal models have suggested that hyperlipidemia is associated with progressive kidney failure data remain sparse on the role of dietary cholesterol intake on kidney disease. METHODS Twelve male New Zealand albino rabbits were randomly divided into two groups (control and cholesterol). Both groups were fed on a standard laboratory diet. Animals in the cholesterol group additionally received cholesterol (1 g/kg/day), orally. The study period was 12 weeks. Activities of catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), nitric oxide synthase (NOS), xanthine oxidase (XO), paraoxonase (PON), adenosine deaminase (ADA) enzymes and levels of malondialdehyde (MDA) and nitric oxide (NO) were measured in kidney tissue samples. Histological examination of the kidney tissue samples was also done. RESULTS SOD, GSH-Px and XO enzyme activities were found to be decreased and NOS and PON activities increased significantly in cholesterol group compared to controls. As an indication of oxidation, MDA levels were found to be increased in cholesterol group. Histological examination revealed some derangements in the kidney tissue. CONCLUSION High cholesterol diet creates oxidant load and causes peroxidation, which in turn, leads derangements in the rabbit kidney tissue (Tab. 2, Fig. 2, Ref. 69).

Echinacea Inhibits Adenosine Deaminase Enzyme in Cancerous Human Gastric Tissue

Aim: This study aims to investigate the possible effects of aqueous Echinacea (E. Purpurea, whole plant) extract on Adenosine deaminase (ADA) activity in cancerous and non-cancerous human gastric and colon tissues. Materials and Methods: Thirty three cancerous and 33 non-cancerous human gastric tissues, and 25 cancerous and non-cancerous human colon tissues removed by surgical operations were studied. In the samples, adenosine deaminase activities were measured with and without extract incubation. Results: It has been observed that Echinacea extract inhibits ADA enzyme in cancerous gastric tissues significantly. It exerts however no inhibitory effects on the ADA activities in the other tissues. Conclusion: It is proposed that inhibition of ADA enzyme by the Echinacea extract might play part in anti-cancer mechanism of Echinacea in some cancers like gastric cancer.

Aqueous extracts of Rosmarinus officinalis, Urtica diocia, and soybean exert different effects on adenosine deaminase activity in cancerous and noncancerous human gastric and colon tissues

Objective: This study aimed to investigate effects of aqueous extracts of Rosmarinus officinalis, Urtica diocia, and soybean on adenosine deaminase (ADA) activity in cancerous and noncancerous gastric and colon tissues since it is key enzyme participating in DNA turn-over. Materials and Methods: In method, cancerous and noncancerous human gastric and colon tissues removed by surgical operations were studied. In the samples, ADA activities were measured with and without plant extract incubated for 1 h. Results: As a result, it has been observed that rosemary extract inhibits ADA enzyme in cancerous (P = 0.031) and noncancerous gastric tissues (P = 0.048), but not in colon tissues, and Urtica extract inhibits the enzyme only in the cancerous gastric tissue (P = 0.039). On contrast, soybean extract activates ADA enzyme in colon tissues significantly (P = 0.012). Conclusion: Inhibition of ADA enzyme might play a part in the proposed anti-cancer properties of rosemary and U. diocia. However, the finding of ADA activation in colon tissues by soybean extract is a new one which needs further verification.

Static magnetic field inhibits 5′ nucleotidase activity in cancerous and non-cancerous human gastric tissues

Abstract The aim of the present study is to investigate possible effects of static magnetic field (SMF) on 5′ nucleotidase (5′NT-CD73) and xanthine oxidase (XO) activities in cancerous and non-cancerous human gastric tissues in order to contribute to the elucidation of the anticancer activity of SMF. Cancerous and non-cancerous human gastric tissues removed from patients by surgical operations were used in the studies. SMF was created using two static magnets. Before and after treatment with SMF, 5′NT and XO activities in the tissue samples were measured. 5′NT activity was found to be lowered, but no significant change was observed in XO activity in the gastric tissues treated with the SMF. Our results suggest that SMF inhibits 5′NT enzyme in gastric tissues significantly. It is supposed that in addition to other proposed mechanisms, inhibition of purine catabolic activity due to inhibition of some key enzymes in the DNA turn-over like 5′NT might also play part in the anticancer activity of SMF.