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Six monocultivar virgin olive oils (VOOs) produced from five autochthonous (Buža, Buža Puntoža, Istarska Bjelica, Porečka Rosulja, and Rosinjola) and one referent cultivar (Leccino), were investigated. The mass fractions of orthodiphenols (ORT) and tocopherols (TOC) were analysed by VIS spectroscopy and HPLC. The radical-scavenging capacity was evaluated by electron spin resonance spectroscopy (ESR) using galvinoxyl free radical and the DPPH test. Results revealed a high level of total TOC in VOOs of Buža Puntoža (243 mg kg−1) and Porečka Rosulja (325 mg kg−1). VOOs contained in 100 g from 79% (Istarska Bjelica) to 261% (Porečka Rosulja) of recommended daily allowance of α-tocopherol. The mass fraction of ORT in Istarska Bjelica and Rosinjola was >250 mg kg−1 (on average 30–40% higher in comparison to other studied cultivars). Istarska Bjelica and Porečka Rosulja showed the highest antioxidant capacity in both methods of measurement. The highest capacity to inhibit protein carbonylation (PC) in response to oxidative stress (54–56%) was displayed by Buža Puntoža, Leccino, and Buža. High level of positive linear correlation between ORT mass fraction and radical-scavenging capacity measured by DPPH test (r=0.768), as well as strong negative correlation between PC inhibition and mass fraction of ORT (r= −0.697), were observed.
The chlorogenic acid and the total polyphenol content were analysed in two different potato varieties (Kennebec, Agria) grown under five different nitrogen fertiliser rates (0, 75, 150, 225, 300 kg ha-1). Chlorogenic acid content ranged between 6.0-22.3 mg kg-1 fresh weight and was not influenced by fertiliser levels. The chlorogenic acid in potato tubers accounted for almost 90% of the total polyphenols. Free radical scavenging and antioxidant activities of the tubers were also analysed. Ethanolic extracts if the tubers showed marked hydrogen-donating activity in the experiment using 1,1-diphenyl-2-picrylhydrazyl (DPPH), they had reducing power as measured by the Fe(III)?Fe(II) reaction, but did not exhibit H2O2 scavenging activity assessed with a chemiluminescence method. Potato extracts showed significant, although weak Cu(II)-chelating activity and inhibited the autoxidation of linolenic acid as measured by the thiocyanate method. Chlorogenic acid containing extract of potato, can act as primary and secondary antioxidant in prevention of oxidative stress. The strong correlation between the antioxidant activity and the level of total pholyphenols suggests that the phenolic compounds are important antioxidant components of whole potato tubers. Variety had minimal, while nitrogen fertiliser rate had no effects on the levels of the studied characteristics.
The use of melatonin as antioxidant has been extensively established. But what would the antioxidant function be if one were to go one step back in the anabolism of that amine, and orally administer its precursor — the amino acid tryptophan? Diurnal animals ( Streptopelia roseogrisea ) were administered orally capsules containing 125 or 300 mg L-tryptophan/kg b.w. for 7 days at the end of the light period (20 h ). A control group received capsules with methylcellulose. The antioxidant function was studied through the reduction of nitroblue tetrazolium (NBT) by superoxide anion, and through the levels of malonaldehyde (MDA) produced in the lipoperoxidation that occurs from the respiratory burst in response to the presence of a foreign particle in phagocytic cells (heterophils), which were extracted at 2 h — at the acrophase of melatonin in the blood stream. In the heterophils extracted from the group that received 125 mg kg −1 b.w. tryptophan, there was less oxidative stress as determined by the NBT reduction than in those from the 300 mg kg −1 b.w. group. In the study of the lipoperoxidation of the membranes as determined by the levels of MDA, however, no significant variations were observed between the different groups. The lower concentration (125 mg L-tryptophan/kg b.w.), administered orally, succeeded in diminishing the free radicals produced in the heterophils for the destruction of the ingested foreign agent, but not fully or maximally. The possible solution to this prooxidant/antioxidant imbalance would be to administer a lower concentration of tryptophan to attain the perfect balance for application in nutritional treatments.
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the levels of inflammatory mediators such as TNF-α and IL-1β ( Liu et al., 2017a ), aging-induced oxidative stress by inhibiting malondialdehyde production, and increasing antioxidant enzymes. It was found that senile plaques appeared in the cortex and
antioxidant status (TAS), the oxidative stress index (OSI) was obtained ( Sevindik, 2019 ). Plant extract stock solutions with concentrations of 0.25, 0.5, 1, and 2 mg mL −1 were prepared for the DPPH assay. DMSO was used to get the desired concentrations
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, neuroinflammation, neural network remodelling, and neuron functional reconfiguration ( Sacco et al., 2013 ; Feigin et al., 2021 ). The overall positive effects of prophylactic IF to protect brain tissue against excitotoxicity, oxidative stress, and inflammation in
ohamed , S.R. , E l -N ekeety , A.A. , H assan , N.S. , A ly , S.E. & A bdel -W ahhab , M.A. ( 2011 ): Ability of Lactobacillus casei and Lactobacillus reuteri to protect against oxidative stress in rats fed aflatoxins-contaminated diet
