Canavanine Increases the Content of Phenolic 
Compounds in Tomato (Solanum lycopersicum L.) Roots

Canavanine (CAN) is a nonproteinogenic amino acid, and its toxicity comes from its utilization instead of arginine in many cellular processes. As presented in previous experiments, supplementation of tomato (Solanum lycopersicum L.) with CAN led to decreased nitric oxide (NO) level and induced secondary oxidative stress. CAN improved total antioxidant capacity in roots, with parallel inhibition of enzymatic antioxidants. The aim of this work was to determine how CAN-dependent limitation of NO emission and reactive oxygen species overproduction impact content, localization, and metabolism of phenolic compounds (PCs) in tomato roots. Tomato seedlings were fed with CAN (10 and 50 µM) for 24 or 72 h. Inhibition of root growth due to CAN supplementation correlated with increased concentration of total PCs; CAN (50 µM) led to the homogeneous accumulation of PCs all over the roots. CAN increased also flavonoids content in root tips. The activity of polyphenol oxidases and phenylalanine ammonia-lyase increased only after prolonged treatment with 50 µM CAN, while expressions of genes encoding these enzymes were modified variously, irrespectively of CAN dosage and duration of the culture. PCs act as the important elements of the cellular antioxidant system under oxidative stress induced by CAN.

Download Full-text

The Oxidative Stress in Knee Osteoarthritis Patients. An Attempt of Evaluation of Possible Compensatory Effects Occurring in the Disease Development

Medicina ◽

10.3390/medicina55050150 ◽

2019 ◽

Vol 55 (5) ◽

pp. 150 ◽

Cited By ~ 5

Author(s):

Marek Paździor ◽

Małgorzata Kiełczykowska ◽

Jacek Kurzepa ◽

Dorota Luchowska-Kocot ◽

Joanna Kocot ◽

...

Keyword(s):

Oxidative Stress ◽

Antioxidant Status ◽

Total Antioxidant Status ◽

Therapeutic Agents ◽

Disease Development ◽

Enzymatic Antioxidants ◽

Compensatory Mechanisms ◽

Knee Oa ◽

Total Antioxidant ◽

Antioxidant Supplements

Background and Objective: Osteoarthritis (OA) is a disorder of the musculoskeletal system resulting in worsening of life condition. The research revealed the involvement of oxidative stress into both OA pathogenesis and the effects of therapeutic agents applied in OA cases. The activities of the most important antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant status (TAS), in blood of the knee OA patients were studied, with the aim of clarifying which enzymatic antioxidants are involved into osteoarthritis (OA)-related oxidative stress and whether any compensatory effects occur. The results were additionally analyzed with regard to gender. Methods: Whole blood SOD (U/mL), plasma GPx (U/L) and CAT (U/mL) activities as well as plasma TAS (mmol/L)) in knee OA patients were investigated. Sixty-seven patients (49 females and 18 males) with primary knee OA were enrolled. The control comprised 21 subjects (10 females and 11 males) free of osteoarthritis or inflammation. Results: TAS was decreased in OA subjects (4.39 ± 0.53 vs. 4.70 ± 0.60), with this effect being more significant in OA females (4.31 ± 0.51 vs. 5.02 ± 0.54). GPx was depressed in all OA patients (518 ± 176 vs. 675 ± 149). In both genders, GPx was decreased, significantly in males (482 ± 185 vs. 715 ± 105). SOD was decreased in all OA patients (109 ± 32 vs. 127 ± 42). CAT showed no difference in all OA subjects vs. control, while in OA females it was depleted (20.2 (11.6–31.6) vs. 38.5 (27.9–46.6)) and in OA men it increased (26.9 (23.3–46.5) vs. 14.0 (7.0–18.6)). Conclusions: The obtained results suggest that in men some compensatory mechanisms towards OA-related oxidative stress occurred. Based on the obtained data, the introduction of antioxidant supplements into OA therapy could be suggested with further research concerning the choice of agents.

Download Full-text