Effect of pH extraction buffer on antioxidant enzymes activities in water lily’s leaves and petioles

Water lily (Nymphaea antares) is one of the most valuable aquatic ornamental plants which has bright potential in the floriculture industry. It may be useful as an urban ecosystem and as a source of medicinal compounds. Due to its potential to become a new value-added product in the food industry, water lily (N. antares) was investigated in this study. Therefore, the goal of this study was to determine the nutritional content and antioxidant activity in water lily leaves and petioles with different pH extraction buffers. Water lily extract was obtained using three different pH extraction buffers, Tris buffer at pH 6.8, pH 7.1 and pH 7.8. The heat capacity of the extract was analysed using differential scanning calorimetry (DSC) and different functional groups were identified using Fourier transform infrared spectroscopy (FTIR). Thermal denaturation of the leaves sample was detected at 81.84°C. The antioxidant enzymes activities including catalase (CAT), peroxidase (POX), polyphenol oxidase (PPO), and superoxide dismutase (SOD) were determined in the leaves and petioles of water lily. In leaves, PPO activity was found to be higher in samples with pH 7.1 of the extraction buffer while there were no significant differences for activities of CAT, POX and SOD in all samples. In petioles, PPO and POX activity were found to be higher in samples with pH 7.8 and 7.1 of extraction buffer, respectively. Thus, the study found that a pH range of 7 to 9 extraction buffers did not greatly affect most of the analysis performed.

Effects of the Combination of High-intensity Interval Training and Ecdysterone on Learning and Memory Abilities, Antioxidant Enzymes Activities, and Neuronal Population in an Amyloid-beta-induced Rat Model of Alzheimer’s Disease

Aims: Oxidative stress and neuronal death are the primary reasons for the progression of amyloid-beta (Aβ) deposition and cognitive deficits in Alzheimer’s disease (AD). Ecdysterone (Ecdy), a common derivative of ecdysteroids, possesses free radical scavenging and cognitive-improving effects. High-intensity interval training (HIIT) may be a therapeutic strategy for improving cognitive decline and oxidative stress. The present study was aimed to evaluate the effect of HIIT alone and its combination with Ecdysterone on the changes in learning and memory functions, hippocampal antioxidant enzymes activities, and neuronal population after AD induced by Aβ in male rats.Materials and methods: Following ten days of Aβ-injection, HIIT exercise and Ecdysterone treatment (10 mg/kg/day; P.O.) were initiated and continued for eight consecutive weeks in rats. At the end of the treatment period, rat’s learning and memory functions were assessed using water-maze and passive-avoidance tests. Moreover, the activity of superoxide dismutase (SOD), catalase (CAT), Glutathione Peroxidase (GPx), Glutathione Reductase (GRx) and neuronal population were evaluated in rat’s brains.Results: The results indicated that Aβ injection disrupted spatial/passive avoidance learning and memory in both water-maze and passive-avoidance paradigms, accompanied by a decrease in the superoxide dismutase and catalase (as endogenous antioxidants) in rat hippocampus. Additionally, Aβ injection resulted in neuronal loss in the cerebral cortex and hippocampus. Although consumption of Ecdysterone separately improved spatial/passive avoidance learning and memory impairments, recovered hippocampal activity of SOD, CAT, GRx, GRx and prevented the hippocampal neuronal loss, its combination with HIIT resulted in a more powerful and effective amelioration in all the above-mentioned Aβ-neuropathological changes.Conclusion: The current work's data confirms that a combination of HIIT exercise and Ecdysterone treatment could be a promising potential therapeutic agent against AD-associated cognitive decline, owing to their free radical scavenging and neuroprotective properties.

Effects of short- and long-term treatments of sardine (Sardina pilchardus) protein hydrolysates on blood lipid concentrations and antioxidant status, in rats fed cholesterol-enriched diets

Hypercholesterolemia is a major risk factor of cardiovascular diseases (CVD). A limited number of experimental studies have shown that sardine protein hydrolysates (SPH) could be a very useful natural compound to prevent hy-percholesterolemia by both improving the lipoprotein profile and modula-ting oxidative stress. In the present study, the effect of short and long term treatments with SPH were examined on serum lipid contents, lipid peroxida-tion and antioxidant enzymes activities in rats fed cholesterol-enriched diet. At day 0, rats were divided into five groups. The group of day 0 was the stan-dard group, and the four remaining groups were divided into two parts of two groups each consuming for 14 or 28 days an hypercholesterolemic diet, and treated (HC-SPH) or not (HC) by gavage with SPH. Compared with day 0, serum TC contents were increased at day 14 and remained unchanged at day 28 in HC-SPH group. These values were decreased in HC-SPH versus HC. Liver and heart TBARS concentrations were increased at day 14 then diminished at day 28 in HC-SPH group. Liver and heart SOD and CAT activities were decrea-sed at short term then remained unchanged at long term in HC-SPH group. In addition, these activities were enhanced in HC-SPH versus HC. In conclusion, these results indicate the potential effects of short and long term treatments of SPH to improved cholesterolemia and reduced radical attack in rats fed high-cholesterol diets.

Abscisic Acid Mediates Grafting-Induced Cold Tolerance of Watermelon via Interaction With Melatonin and Methyl Jasmonate

Grafting is widely used to increase plant defense responses to various stresses. Grafting-induced cold tolerance is associated with the increase of the antioxidant potential of plants; however, the underlying mechanisms remain unclear. Here, we found that pumpkin rootstocks promote antioxidant enzyme activities and alleviate cold-induced oxidative damage, accompanied by increased abscisic acid (ABA), melatonin, and methyl jasmonate (MeJA) levels in leaves. Increased ABA accumulation in leaves was attributed partly to the increased ABA levels in rootstocks. ABA induced antioxidant enzymes activities and the accumulation of melatonin and MeJA, while inhibition of ABA synthesis blocked the rootstock-induced antioxidant activity and the accumulation of melatonin and MeJA under cold stress. Melatonin and MeJA application also enhanced ABA accumulation in leaves after cold exposure, whereas inhibition of melatonin or MeJA synthesis attenuated the rootstock-induced increase of ABA. Moreover, melatonin and MeJA application alleviated cold-induced oxidative stress, but inhibition of melatonin or MeJA synthesis lowered the rootstock- or ABA-induced antioxidant potential and tolerance to cold. These findings indicate that ABA plays an important role in the grafting-induced cold tolerance by promoting the accumulation of melatonin and MeJA, which in turn, promote ABA accumulation, forming a positive feedback loop.

Amelioration of oxidative stress-mediated cytotoxicity and genotoxicity induced by copper and flubendiamide in-vivo and in- vitro by potent antioxidants

Present study was designed to assess the toxicity of copper @ 33 mg/kg and flubendiamide @ 200 mg/kg in vivo in male Wistar rats orally once daily for 90 days and protective effect of α-tocopherol, resveratrol, curcumin and catechin and in vitro cyto-genotoxicity in primary cell culture of thymocytes. In vivo study showed significant (p<0.05) increase in AST, total bilirubin and uric acid, creatinine and BUN levels while decrease in total proteins, GSH, SOD and GST levels and increased LPO and GPx with severe degenerative changes were observed in liver and kidney tissues in intoxicated groups. In vitro thymocytes were exposed to 40 µM concentration of flubendiamide and/or showed significant increase in TUNEL+ve cells, micronuclei, DNA shearing, and comet formation per 100 cells. Concurrent treatment with α-tocopherol in xenobiotics intoxicated groups showed almost normal values of the biochemical parameters and decreased LPO production and improved antioxidant enzymes activities and histoarchitecture of liver and kidney tissues suggest ameliorative potential of α-tocopherol whereas, resveratrol, curcumin, catechin or α-tocopherol in vitro decreased TUNEL+ve cells, micronuclei induction and comet formation and effect of antioxidants was concentration-dependent and their order of potency on equimolar concentration (10 µM) basis is: curcumin > resveratrol >catechin = α-tocopherol.

Response of enzymatic and non-enzymatic antioxidant systems in Excoecaria agallocha to salt stress

The effect of NaCl stress on antioxidant enzymes activities was investigated in the leaves of Excoecaria agallocha. Plants were subjected to different levels of NaCl. 100 to 1000 mM. Above 500 mM these mangrove seedlings did not survive. The leaves of 60 day old plants were used for the analysis of enzyme activities. Parameters of enzymatic and non enzymatic antioxidants such as catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), polyphenol oxidase (PPO), superoxide dismutase (SOD), ascorbic acid (ASA) and alpha tocopherol were determined. The highest CAT, POD, APX, PPO and SOD activities in the leaf and root enhanced gradually up to 300 mM of NaCl, the highest ASA and tocopherol activities in the leaf and root were observed at 500 mM of NaCl. These data suggest that the capacity to limit oxidative damage is important for the salt tolerance of E. agallocha.