Ilex paraguariensis is a native species to South America. Its economic importance is in the use of its leaves and twigs in the processing of a product popularly known as "chimarrão". The aim of this study was to evaluate the correlations between some physico-chemical process parameters in the oxidation of I. paraguariensis leaves oxidation. The leaves of Maté with age 1.0, 6.5 and 12.0 months were subjected to an oxidation process for 3 h under different relative humidity conditions (80, 90 and 99%) at 26°C. The extracts were evaluated using the experimental design techniques to maximize the oxidation conditions for the total polyphenols, antioxidant capacity, water activity and color. The condition of 90% humidity and leaf age 6.5 months resulted in lower lightness and yellow color of the product. Green color was not significantly influenced by the studied parameters. The highest levels of total phenols and antioxidant potential were found when the leaf age was one month and humidity was 90%. Thus, it could be concluded that the air humidity of the chamber and leaf age influenced the oxidation process of the leaves of Maté as well as the antioxidant capacity of the extract obtained.

Cultivation of plants in environments polluted by metals at toxic levels can affect the biosynthesis of secondary metabolites. Here, we analysed the effect caused by excess copper on the concentration of chlorophylls a and b and the profile of secondary metabolites of Lantana fucata leaves. Five copper (Cu) treatments (mg Cu kg−1 soil) were tested: T0, 0; T1, 210; T2, 420; T3, 630; and T4, 840. We found that the concentrations of chlorophylls in the plants decreased when compared to the control. However, this did not lead to a significant reduction in its growth, possibly due to the low translocation of the metal to shoots and the activation of plant defence systems to tolerate the environment in which they are exposed, increasing the emission of lateral roots and activating pathways for the production of secondary metabolites. Therefore, we found a decrease in the concentration of two key compounds in secondary metabolism, p-coumaric and cinnamic acids in treatments with higher copper concentrations. We also found an increase in phenolics. Decreases in p-coumaric and cinnamic acids may have occurred because these are precursors in the synthesis of phenolic compounds, which are increased in the high Cu treatments. Six secondary metabolites were characterised, described for the first time for this plant species. Thus, the presence of excess Cu in the soil may have triggered an increase in the amount of reactive oxygen species in the plants, which that led to the synthesis of antioxidant compounds, as a defence strategy.

Background: Levels of chronic inflammation, oxidative stress, and neurotransmitter availability are altered in depressed patients and can be used as biological markers. This study aimed to analyze these markers in female Wistar rats under chronic inflammation induced by E. coli lipopolysaccharide (LPS), treated with aqueous extract of A. gratissima and rutin, the major flavonoid of its extract. Methods: Thirty female Wistar rats under a chronic inflammatory regimen induced by 1 mg/kg i.p. of LPS were divided into six experimental groups: control (1), treated with fluoxetine 5 mg/kg (2), rutin at 50 mg/kg (3) or 100 mg/kg (4), aqueous extract of A. gratissima 100 mg/kg (5), and co-treatment with 50 mg/kg of extract and 10 mg/kg of rutin (6). Treatments were administered by gavage for 15 days. Results: Oxidative damage to proteins and lipids was lower in group 6 compared to group 2. Pro- and anti-inflammatory cytokines increased in group 1 but not in group 2, indicating a relationship with depression. Similar effects were observed in the treated groups, showing no significant differences from group 2. Neurotransmitter levels of dopamine and serotonin were low in group 1, and all treatments effectively increased them. Additionally, A. gratissima extract at 100 ppm increased locomotor activity in planarians. Conclusions: This study demonstrates the effectiveness of the LPS induction model in subacute experimental designs and the potential antidepressant effect of the treatments due to their antioxidant and anti-inflammatory properties, and ability to increase neurotransmitter levels.