Importance Of Antioxidant Enzymes Research Articles

The Importance of Antioxidant Enzymes and Oxidative Stress in Human Fascioliasis

The aim of this study was to determine the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and malondialdehyde (MDA) in the patients infected with Fasciola hepatica and establish whether these parameters differ among the patients with fascioliasis. The patient group consisted of 140 individuals with F. hepatica seropositive; the control group consisted of 140 healthy individuals who tested negative for this parasite and had no other diseases. The patient group consisted of individuals with no chronic diseases other than fascioliasis; in both the patient and the control groups, the subjects had no unhealthy habits such as smoking and alcohol consumption, etc. The blood samples taken to diagnose fascioliasis were evaluated by the ELISA method. The samples were studied according to the kit procedures for SOD, CAT, GPx and MDA markers. In this study, 43.6% of 140 individuals in the patient group infected with F. hepatica had CAT (p=0.001), 35% had GPx (p=0.001), 12.9% had SOD (p=0.002), 90.7% had MDA (p=0.001). There was found a statistically significant difference between the patient and the control group in terms of the positivity of these four parameters. As a result, a statistically significant relationship was found between the increase in the SOD, GPx, CAT, and MDA levels and fascioliasis. The high rate of MDA revealed that oxidative stress occurred in patients with fascioliasis, resulting in an increased activity of SOD, GPx, and CAT. Bu çalışmanın amacı, Fasciola hepatica ile enfekte hastalarda süperoksit dismutaz (SOD), glutatyon peroksidaz (GPx), katalaz (CAT) ve malondialdehit (MDA) düzeylerini belirlemek ve fascioliasisli hastalarda bu parametrelerde farklılık meydana gelip gelmediğini ortaya koymaktır. Hasta grubu, F. hepatica pozitif olan 140 hastadan; kontrol grubu ise bu parazit yönünden negatif bulunan ve başka herhangi bir hastalığı bulunmayan 140 sağlıklı kişiden oluşturuldu. Hasta grubuna fascioliasis dışında herhangi bir kronik hastalığı olmayan ve hem hasta hem de kontrol grubuna sigara, alkol kullanımı olmayan kişiler dahil edildi. Hastalarda fascioliasis pozitifliğini belirlemek için alınan kan örnekleri ELISA yöntemi ile çalışıldı. Serum SOD, CAT, GPx ve MDA düzeyleri ELISA yöntemi ile değerlendirildi. Bu çalışmada F. hepatica ile enfekte hasta grubundaki 140 kişinin %43,6’sında CAT (p=0,001), %35’inde GPx (p=0,001), %12,9’unda SOD (p=0,002) ve %90,7 MDA pozitifliği saptandı. Bu dört parametrenin pozitifliği açısından hasta ve kontrol grubu arasında istatistiksel olarak anlamlı fark bulundu (p=0,001). Sonuç olarak SOD, GPx, CAT ve MDA düzeyindeki artış ile fascioliasis arasında istatistik olarak anlamlı bir ilişki saptanmıştır. Çalışmamızda MDA’nın yüksek oranda saptanmış olması fascioliasisli hastalarda oksidatif stres oluştuğunu ve SOD, GPx ve CAT aktivitelerinde artış olduğunu ortaya koymuştur.

Experimental Evaluation of the Wound-healing and Antioxidant Activities of Tamarind (Tamarindus indica) Pulp and Leaf Meal in the African Catfish (Clarias gariepinus)

DOI : 10.26650/actavet.2018.011 The fruits and leaves of Tamarindus indica have been widely used in traditional medicine for treating wounds and other diseases in Africa. The aim of this study was to investigate the wound-healing property of T. indica pulp (TP) and leaf (TL) meal and the importance of antioxidant enzymes in the wound-healing process in the African catfish, Clarias gariepinus. Surgical incisions of 10 mm2 were made aseptically on the lateral part of the catfish, above the pelvic fin and toward the caudal region. The fish were fed experimental diets composed of basal diet fortified with each of TP or TL at concentrations of 0.5%, 1.0%, 1.5%, 2.0%, and 0.0% (untreated) and 0.2% oxytetracycline (treated) as controls in triplicate groups. Changes occurring in the wound area (mm2) were measured at 3-day-intervals for 15 days. The healing rates and the relative percentage of healing were calculated. Sera collected from the experimental fish were analyzed for oxidative stress biomarkers and antioxidant enzymes. The results showed that fish fed diets treated with TP or TL had significantly faster (p<0.05) daily healing rates at the lateral and caudal regions from the 6th to the 12th day compared with those in the control groups. Percentage wound-healing (PWH) at the lateral and caudal regions was significantly enhanced (p<0.05) from the 6th day in the tamarind-treated groups. The PWH reached the peak (100%) at the lateral region on the 12th day in fish fed 0.5–2.0% of TL and 1.5%–2.0% of TP diets. Dietary treatment with TP and TL resulted in a lower production of serum malondialdehyde and hydrogen peroxide levels, whereas the reduced glutathione, superoxide dismutase, and glutathione peroxidase levels increased. Fortifying diets of C. gariepinus with 1.0%–2.0% of TP and TL meal enhanced wound-healing significantly compared to that of natural healing and with oxytetracycline-fortified diet. The faster wound-healing rate might be a consequence of elevated levels of serum antioxidants in the fish fed tamarind-fortified diets.

Nucleoredoxin guards against oxidative stress by protecting antioxidant enzymes

Cellular accumulation of reactive oxygen species (ROS) is associated with a wide range of developmental and stress responses. Although cells have evolved to use ROS as signaling molecules, their chemically reactive nature also poses a threat. Antioxidant systems are required to detoxify ROS and prevent cellular damage, but little is known about how these systems manage to function in hostile, ROS-rich environments. Here we show that during oxidative stress in plant cells, the pathogen-inducible oxidoreductase Nucleoredoxin 1 (NRX1) targets enzymes of major hydrogen peroxide (H2O2)-scavenging pathways, including catalases. Mutant nrx1 plants displayed reduced catalase activity and were hypersensitive to oxidative stress. Remarkably, catalase was maintained in a reduced state by substrate-interaction with NRX1, a process necessary for its H2O2-scavenging activity. These data suggest that unexpectedly H2O2-scavenging enzymes experience oxidative distress in ROS-rich environments and require reductive protection from NRX1 for optimal activity.

Physical mapping of the human ATX1 homologue (HAH1) to the critical region of the 5q- syndrome within 5q32, and immediately adjacent to the SPARC gene.

The 5q- syndrome is a myelodysplastic syndrome with the 5q deletion as the sole karyotypic abnormality. The human ATX1 homologue (HAH1), encodes a copper-binding protein with a role in antioxidant defence. We have mapped this gene to the 3 Mb critical region of gene loss of the 5q- syndrome within 5q32, flanked by the genes for ADRB2 and IL12B, using gene dosage analysis. Fine physical mapping of the HAH1 gene within this genomic interval was then performed by screening YAC and BAC contigs spanning the critical region of the 5q- syndrome using PCR amplification. The HAH1 gene maps immediately adjacent to the SPARC gene at 5q32, and is flanked by the genetic markers D5S1838 and D5S1419. The HAH1 gene is expressed in haematological tissues and plays a role in antioxidant defence. Antioxidant levels are low in most cancers and the importance of antioxidant enzymes in cancer genesis is well recognised. Genomic localisation, function and expression would suggest that the HAH1 gene represents a candidate gene for the 5q-syndrome.

The importance of antioxidant enzymes in cellular aging and degeneration.

Aerobic cells contain various amounts of the three main antioxidant enzymes: superoxide dismutase (SOD), catalase and GSH peroxidase. These three enzymes are necessary for cell survival since inhibition of their activity leads to the arrest of cell mitosis and to cell death. Amongst them, GSH peroxidase was shown to be more efficient than catalase and much more than SOD. This result was obtained by comparing the cell protection against oxidative stress after their microinjection in the cytoplasm. With age, the level of these antioxidant enzymes does not change in several experimental models, so that it is not possible to explain the aging process by a lack of protection due to a decrease in the activity of these three enzymes. However, tissues and cells are more susceptible to free radical attacks with age. In order to understand the importance of free radicals in this process, we have to distinguish between their respective effects on cell mitosis, cell death and cell aging. The effects on mitosis and cell death are well described, and the results clearly show a threshold of response which is determined by the antioxidant content of the cell. There is now evidence that short free radical stresses can also speed up the aging of in vitro cultured human fibroblasts. However, such effects are not typical of free radicals but are also obtained with many other deleterious substances so that free radicals have to be considered as one amongst other factors responsible for influencing the evolution of a cell to an older stage or to cell death. The lowering of the general metabolism and of the free energy in old cells are probably the main factors responsible for the increased susceptibility of these cells to stresses such as oxidative stresses.