Selenium (Se) is a widely distributed trace element with dual (beneficial or toxic) effects for humans, animals, and plants. The availability of Se in the soil is reliant on the structure of the parental material and the procedures succeeding to soil formation. Anthropogenic activities affect the content of Se in the environment. Although plants are the core source of Se in animal and human diet, the role of Se in plants is still debatable. A low concentration of Se can be beneficial for plant growth, development, and ecophysiology both under optimum and unfavorable environmental conditions. However, excess Se results in toxic effects, especially in Se sensitive plants, due to changing structure and function of proteins and induce oxidative/nitrosative stress, which disrupts several metabolic processes. Contrary, Se hyperaccumulators absorb and tolerate exceedingly large amounts of Se, could be potentially used to remediate, i.e., remove, transfer, stabilize, and/or detoxify Se-contaminants in the soil and groundwater. Thereby, Se-hyperaccumulators can play a dynamic role in overcoming global problem Se-inadequacy and toxicity. However, the knowledge of Se uptake and metabolism is essential for the effective phytoremediation to remove this element. Moreover, selecting the most efficient species accumulating Se is crucial for successful phytoremediation of a particular Se-contaminated area. This review emphasizes Se toxicity in plants and the environment with regards to Se biogeochemistry and phytoremediation aspects. This review follows a critical approach and stimulates thought for future research avenues.

Herbal therapy is a potential alternative applied to pharmacological alleviation of depression symptoms and treatment of this disorder, which is predicted by the World Health Organization (WHO) to be the most serious health problem worldwide over the next several years. It has been well documented that many herbs with psychotropic effects have far fewer side effects than a variety of pharmaceutical agents used by psychiatrists for the treatment of depression. This systematic review presents literature data on the antidepressant activity of representatives of the genera Hemerocallis (H. fulva and H. citrina Baroni, family Xanthorrhoeaceae) and Gladiolus (G. dalenii, family Iridaceae) and on biologically active compounds and their mechanisms of action to consider the application of herbal preparations supporting the treatment of depression.

In nature, plants usually produce secondary metabolites as a defense mechanism against environmental stresses. Different stresses determine the chemical diversity of plant-specialized metabolism products. In this study, we applied an abiotic elicitor, i.e., NaCl, to enhance the biosynthesis and accumulation of phenolic secondary metabolites in Melissa officinalis L. Plants were subjected to salt stress treatment by application of NaCl solutions (0, 50, or 100 mM) to the pots. Generally, the NaCl treatments were found to inhibit the growth of plants, simultaneously enhancing the accumulation of phenolic compounds (total phenolics, soluble flavonols, anthocyanins, phenolic acids), especially at 100 mM NaCl. However, the salt stress did not disturb the accumulation of photosynthetic pigments and proper functioning of the PS II photosystem. Therefore, the proposed method of elicitation represents a convenient alternative to cell suspension or hydroponic techniques as it is easier and cheaper with simple application in lemon balm pot cultivation. The improvement of lemon balm quality by NaCl elicitation can potentially increase the level of health-promoting phytochemicals and the bioactivity of low-processed herbal products.

Psychotropic effect of Crocus sativus L. (family Iridaceae) biologically active chemical compounds are quite well documented and they can therefore be used in addition to the conventional pharmacological treatment of depression. This systematic review on antidepressant compounds in saffron crocus and their mechanisms of action and side effects is based on publications released between 1995–2022 and data indexed in 15 databases under the following search terms: antidepressant effect, central nervous system, Crocus sativus, cognitive impairement, crocin, crocetin, depression, dopamine, dopaminergic and serotonergic systems, picrocrocin, phytotherapy, neurotransmitters, safranal, saffron, serotonin, and biologically active compounds. The comparative analysis of the publications was based on 414 original research papers. The investigated literature indicates the effectiveness and safety of aqueous and alcoholic extracts and biologically active chemical compounds (alkaloids, anthocyanins, carotenoids, flavonoid, phenolic, saponins, and terpenoids) isolated from various organs (corms, leaves, flower petal, and stigmas) in adjuvant treatment of depression and anxiety. Monoamine reuptake inhibition, N-methyl-d-aspartate (NMDA) receptor antagonism, and gamma-aminobutyric acid (GABA)-α agonism are the main proposed mechanism of the antidepressant action. The antidepressant and neuroprotective effect of extract components is associated with their anti-inflammatory and antioxidant activity. The mechanism of their action, interactions with conventional drugs and other herbal preparations and the safety of use are not fully understood; therefore, further detailed research in this field is necessary. The presented results regarding the application of C. sativus in phytotherapy are promising in terms of the use of herbal preparations to support the treatment of depression. This is particularly important given the steady increase in the incidence of this disease worldwide and social effects.

The effect of different sulfate(VI) sulfur (2, 6, and 9 mM S) levels and nickel(II) chloride (0, 0.0004, 0.04 and 0.08 mM Ni) in the nutrient solution on productivity and macronutrient (N, P, K, Ca, Mg, S) status and accumulation in spring wheat (Triticum aestivum L.) Zebra cv. was studied. Ni treatment reduced the biomass and disturbed the balance and accumulation of macronutrients in wheat. Intensive S nutrition, especially with 6 mM S, at least partially increased the biomass, improved ionic equilibrium, and enhanced nutrient accumulation in Ni-exposed plants in spite of increased Ni accumulation. Admittedly, the dose 9 mM S reduced Ni accumulation in shoots but increased accumulation thereof in roots. Compared to 6 mM, the dose 9 mM was less effective in improving the mineral status of Ni-treated wheat.