Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.

This review examines the existing knowledge about Ru(II)/(III) ion complexes with a potential application in medicine or pharmacy, which may offer greater potential in cancer chemotherapy than Pt(II) complexes, which are known to cause many side effects. Hence, much attention has been paid to research on cancer cell lines and clinical trials have been undertaken on ruthenium complexes. In addition to their antitumor activity, ruthenium complexes are under evaluation for other diseases, such as type 2 diabetes, Alzheimer’s disease and HIV. Attempts are also being made to evaluate ruthenium complexes as potential photosensitizers with polypyridine ligands for use in cancer chemotherapy. The review also briefly examines theoretical approaches to studying the interactions of Ru(II)/Ru(III) complexes with biological receptors, which can facilitate the rational design of ruthenium-based drugs.

We present results on the potential protective antioxidant properties of indole-3-butyric acid. Indole-3-butyric acid is an indole derivative defined as an auxin and widely known as a plant growth regulator. It naturally occurs in Arabidopsis thaliana, which is applied as a model plant in genetic studies. Oxidative damage to membrane lipids (lipid peroxidation; LPO) in porcine thyroid homogenates was induced by Fenton reaction substrates (Fe²⁺ + H₂O₂). Iron (Fe²⁺) was used in very high concentrations of 1200, 600, 300, 150, 75, 37.5, 18.75, 9.375, 4.687, and 2.343 µM. Indole-3-butyric acid (10.0, 5.0, 2.5, 1.25, and 0.625 mM) was applied to check whether it prevents the above process. The LPO level, expressed as malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) concentration, was measured spectrophotometrically. Expectedly, Fenton reaction substrates, in a Fe²⁺ concentration-dependent manner, increased LPO level, with the lowest effective concentration of iron being 9.375 µM. In the case of almost all concentrations of indole-3-butyric acid, this auxin has exhibited very promising antioxidant protection, with the most effective concentrations being 10.0 and 5.0 mM; however, as low concentrations of indole-3-butyric acid at 1.25 mM was still effective. Indole-3-butyric acid used alone did not change the basal level of LPO, which is a favourable effect. To summarise, indole-3-butyric acid has protective antioxidant properties against experimentally induced oxidative damage to membrane lipids in the thyroid, and this is for the first time documented in the literature. This compound can be considered a natural protective agent present in plants, which can serve as a dietary nutrient.

Background: Indole-3-carbinol is an indole derivative which is commonly present in vegetables, which belong to Brassicaceae family and has many medicinal properties. This study aimed to investigate the antioxidant impact of indole-3-carbinol on damages caused by Fenton reaction substrates to lipid membranes (lipid peroxidation) of porcine kidneys and ovaries. Methods: Antioxidant effect of indole-3-carbinol was assessed using Lipid Peroxidation Assay. As damaging agents were used Fenton reaction substrates, i.e., FeSO₄ at 11 different concentrations and H₂O₂. The concentrations of indole-3-carbinol were 0.0, 20.0, 10.0, 5.0, 1.0 and 0.5 mM. Results: Comparative analysis showed higher lipid peroxidation levels in kidney than ovary homogenates at 600–18.75 μM FeSO₄. Indole-3-carbinol significantly reduced LPO in porcine ovary homogenates at higher FeSO₄ concentrations (1200–300 μM) in a concentration-dependent manner, while antioxidant effects in kidney homogenates were observed across a broader FeSO₄ range (1200–18.75 μM). Notably, at the lowest FeSO₄ concentrations (4.687–2.343 μM), high doses of indole-3-carbinol (20.0 and 10.0 mM) induced pro-oxidant effects in both tissues. Furthermore, indole-3-carbinol at these concentrations exhibited potential pro-oxidant activity even in samples without added Fenton reaction substrates. Conclusions: Indole-3-carbinol has dose-dependent antioxidant effects in porcine ovary and kidney homogenates under high oxidative stress, reducing Fenton reaction-induced lipid peroxidation. However, high doses of indole-3-carbinol exhibited pro-oxidant effects at lower prooxidant concentration and under basal conditions (i.e., without addition of prooxidant), highlighting the importance of dose and oxidative conditions in its potential therapeutic use.

Indoles are chemical compounds that naturally occur in Prokaryotes and Eukaryotes. For example, indole alkaloids mainly occur in plant families such as Nyssaceae, Rubiaceae, Apocynaceae, and Loganiaceae. The popularity of indoles has led to further research into their function and synthetic modification. Meanwhile, the Wnt (Wingless and Int-1) signaling pathway is responsible for cell regulatory processes, while its dysfunction often constitutes the molecular basis for the pathogenesis of neoplastic processes. Databases such as PubMed, Scopus, Google Scholar, and Science Direct were used to perform a literature search with keywords including “indoles” and those related to their biological activity, as well as “Wnt pathway” and “thyroid cancer (TC)”. We used ClinicalTrials.gov to search current clinical trials for selected indoles, such as melatonin, indole-3-propionic acid, and indole-3-carbinol. While indoles possess many therapeutic properties, we focused here on the following: antitumor, antiviral, anti-inflammatory, antidepressant, antimigraine, antiemetic, and antihypertensive activities. We analyzed the Wnt pathway and its disruptions in thyroid cancer. In this manuscript, seventy-six (76) indoles, which have natural and synthetic origins, are presented. In addition to all activities mentioned, we discuss the therapeutic goals of indole applications in anticancer research. The Wnt signaling pathway can be changed in tumor cells, and such disruptions can occur in thyroid cancers.