Regulatory Role of UV-B in Modulating Antioxidant Defence System of Plants

Author(s):  
Abreeq Fatima ◽  
Madhulika Singh ◽  
Sheo Mohan Prasad
Author(s):  
Augustine Apiamu ◽  
Samuel Ogheneovo Asagba ◽  
Nyerhovwo J. Tonukari

Abstract Background Cadmium (Cd) toxicity, which runs across the food chain, is chiefly regulated by in vivo antioxidant defence system or through antioxidant supplementation of biological systems predisposed to this environmental stressor. The present study was designed to examine the role of Anthocleista vogelii leaves in Cd-induced oxidative stress in the serum of Wistar rats through the application of response surface methodology (RSM) and biomonitoring of selective responses: malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione-s-transferase (GST) and peroxidase (POD) activities, respectively. The cold macerated plant leaves were subjected to fractionation process using methanol-hexane-chloroform (3:2:1 v/v) solvent system such that n-hexane fraction with ample antioxidant levels in terms of total phenolic content (TPC) and total flavonoid content (TFC) among others at p <  0.05 was selected for the study. The study employed central composite design (CCD) with twenty experimental “runs” of male Wistar rats for twenty-eight days, following a week of acclimatization, where n-hexane fraction of A. vogelii (NFAV), cadmium chloride (CdCl2) and body weights of rats were considered input factors in the study. Results The study generated five quadratic models, which differed significantly at p <  0.05 for MDA levels as well as CAT, SOD, GST and POD activities in the sera of Wistar rats. The study revealed that exposure to Cd toxicity caused a marked increase (p <  0.05) in serum MDA levels, but a significant inhibition (p <  0.05) of serum SOD, CAT, GST and POD activities. However, Cd interaction with NFAV showed marked amelioration of Cd-induced oxidative stress, which was confirmed by significant decrease in serum MDA levels, but significant increase in serum SOD, CAT, GST and POD activities at p <  0.05 via the response surface plots. The study also confirmed the reliability and adequacy of the models for accurate prediction of the responses since R-squared (R2) values obtained were greater than 90%. Conclusion It was inferred from the present study that the adequacy of the models validated the potency of A. vogelii leaves graphically in the amelioration of Cd-induced oxidative stress in the serum of Wistar rats. Hence, the plant was considered a rich source of bioactive compounds with significant antioxidant properties.


1996 ◽  
Vol 28 (6) ◽  
pp. 336-342 ◽  
Author(s):  
Yoshiji Ohta ◽  
Takashi Yamasaki ◽  
Takafumi Niwa ◽  
Katsuhiko Niimi ◽  
Yoshinao Majima ◽  
...  

Parasitology ◽  
2007 ◽  
Vol 134 (7) ◽  
pp. 959-965 ◽  
Author(s):  
A. CICCARELLI ◽  
L. ARAUJO ◽  
A. BATLLE ◽  
E. LOMBARDO

SUMMARYA nutritional characteristic of trypanosomatid protozoa is that in vitro they need a haem-compound as a growth factor, which is supplied as haemoglobin, haematin or haemin. Because haemin and related porphyrins are an important source of oxidative stress in biological systems, the effect of haemin on growth, protein content and the antioxidant defence system in Trypanosoma cruzi was evaluated. We have observed that, in epimastigotes grown under different haemin concentrations in the culture medium (0–30 mg/l), 5 mg/l was the haemin concentration yielding optimum growth. Above 15 mg/l there was a clear decrease in growth rate, producing the epimastigote to amastigote transformation. Such morphological change was observed together with a marked injury of the enzymatic machinery of the parasite, leading to diminished protein synthesis as well as lower activity of the antioxidant enzymes (superoxide dismutase, ascorbate peroxidase and trypanothione reductase), reduced total thiol content and a marked increase in the HaemOx-1 activity and expression. The current work demonstrates that there is a correlation between higher haemin concentrations in the culture medium and oxidative damage in the cells. Under these conditions induction of HaemOx-1 would indicate the important role of this enzyme as an antioxidant defence response in Trypanosoma cruzi.


Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 267 ◽  
Author(s):  
Vishnu D. Rajput ◽  
Harish ◽  
Rupesh Kumar Singh ◽  
Krishan K. Verma ◽  
Lav Sharma ◽  
...  

The stationary life of plants has led to the evolution of a complex gridded antioxidant defence system constituting numerous enzymatic components, playing a crucial role in overcoming various stress conditions. Mainly, these plant enzymes are superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferases (GST), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR), which work as part of the antioxidant defence system. These enzymes together form a complex set of mechanisms to minimise, buffer, and scavenge the reactive oxygen species (ROS) efficiently. The present review is aimed at articulating the current understanding of each of these enzymatic components, with special attention on the role of each enzyme in response to the various environmental, especially abiotic stresses, their molecular characterisation, and reaction mechanisms. The role of the enzymatic defence system for plant health and development, their significance, and cross-talk mechanisms are discussed in detail. Additionally, the application of antioxidant enzymes in developing stress-tolerant transgenic plants are also discussed.


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