Azulene is an aromatic hydrocarbon that possesses a unique chemical structure and interesting biological properties. Azulene derivatives, including guaiazulene or chamazulene, occur in nature as components of many plants and mushrooms, such as Matricaria chamomilla, Artemisia absinthium, Achillea millefolium, and Lactarius indigo. Due to physicochemical properties, azulene and its derivatives have found many potential applications in technology, especially in optoelectronic devices. In medicine, the ingredients of these plants have been widely used for hundreds of years in antiallergic, antibacterial, and anti-inflammatory therapies. Herein, the applications of azulene, its derivatives and their conjugates with biologically active compounds are presented. The potential use of these compounds concerns various areas of medicine, including anti-inflammatory with peptic ulcers, antineoplastic with leukemia, antidiabetes, antiretroviral with HIV-1, antimicrobial, including antimicrobial photodynamic therapy, and antifungal.

Contamination of the environment has been a growing problem in recent years. Due to the rapid growth in human population, the expansion of cities, along with the development of industry, more and more dangerous chemicals end up in the environment, especially in soil and water. For the most part, it is not possible to effectively remove chemicals through traditional remediation techniques, because those used in treatment plants are not specifically designed for this purpose. Therefore, new approaches for water remediation are in great demand. Many efforts have been focused on applications of photocatalysis for the remediation of chemical pollutants including drugs. Titanium(IV) oxide nanoparticles have particularly been considered as potential photocatalysts due to their favorable properties. In this article, we present the problem of emerging contaminants including drugs and discuss the use of photocatalysts based on titanium(IV) oxide nanoparticles for their degradation. A wide selection of materials, starting from bare TiO₂, via its hybrid and composite materials, are discussed including those based on carbonaceous materials or connections with macrocyclic structures. Examples of photodegradation experiments on TiO₂-based materials including those performed with various active pharmaceutical ingredients are also included.

Epigallocatechin gallate (EGCG) is a polyphenol present in green tea (Camellia sinensis), which has revealed anti-cancer effects toward a variety of cancer cells in vitro and protective potential against neurodegenerative diseases such as Alzheimer's and Parkinson's. Unfortunately, EGCG presents disappointing bioavailability after oral administration, primarily due to its chemical instability and poor absorption. Due to these limitations, EGCG is currently not used in medication, but only as a dietary supplement in the form of green tea extract. Therefore, it needs further modifications before being considered suitable for extensive medical applications. In this article, we review the scientific literature about EGCG derivatives focusing on their biological properties and potential medical applications. The most common chemical modifications of epigallocatechin gallate rely on introducing fatty acid chains or sugar molecules to its chemical structure to modify solubility. Another frequently employed procedure is based on blocking EGCG's hydroxyl groups with various substituents. Novel derivatives reveal interesting properties, of which, antioxidant, anti-inflammatory, antitumor and antimicrobial, are especially important. It is worth noting that the most promising EGCG derivatives present higher stability and activity than base EGCG.

Curcumin, a naturally occurring compound found in the rhizome of Curcuma plants, particularly in turmeric (Curcuma longa L.), exhibits a broad range of biological activities, including anti-inflammatory, antioxidant, and anticancer properties. Curcumin has demonstrated effectiveness in inhibiting tumor growth, arousing interest for its potential in treating various cancers, such as breast, lung, prostate, and brain cancers. However, the clinical application of curcumin is limited due to its low chemical stability, poor water solubility, and low bioavailability. In response to these challenges, structural modifications of curcumin have been explored to improve its pharmacological properties, including enhanced anticancer selectivity index and bioavailability. This review highlights promising chemical modifications of curcumin that could lead to the development of more effective anticancer therapies. By functionalizing the parent curcumin molecule, researchers aim to create more stable and bioavailable compounds with enhanced therapeutic potential, making curcumin derivatives promising candidates for medical applications.

Green tea extract (GTE) is one of the most popular beverages globally, traditionally prepared from Camelia sinensis leaves. Therefore, it is beneficial to define the impact of GTE and its ingredients on the human organism. Epigallocatechin-3-O-gallate (EGCG) is the most abundant catechin in green tea leaves, belonging to the group of tannins and flavonoids, demonstrating pharmacological activity, but so far, it has not been applied as a drug. This is because EGCG does not present sufficient stability and quickly decomposes through epimerization or autooxidation mechanisms under the influence of light, temperature, changes in pH, or the presence of oxygen. Another limiting factor is EGCG’s low bioavailability after oral administration. Nevertheless, the growing market of dietary supplements together with increasing growing consumption of green tea extracts should prompt us to pay more attention to the safety of both EGCG itself, as well as its influence on other simultaneously used drugs. Previously published data confirm the relationship between healthcare professionals’ access to professional knowledge and their willingness to engage in patient education. For this reason, in this review article, we report the formulations of EGCG and GTE, discuss the data on the safety of EGCG and its possible interactions with drugs, as well as gather various recommendations from medical specialists. Particular attention should be paid to the consumption of green tea during pregnancy and breastfeeding, as well as in the elderly. Patients taking clozapine, digoxin, and warfarin should avoid consuming GTE extracts and dietary supplements containing EGCG. Professional consultation seems especially important for patients treated with statins, calcium channel blockers, or sildenafil.

Gold nanoparticles (AuNPs), as an agent enhancing radiosensitivity, play a key role in the potential treatment of breast cancer (BC). Assessing and understanding the kinetics of modern drug delivery systems is a crucial element that allows the implementation of AuNPs in clinical treatment. The main objective of the study was to assess the role of the properties of gold nanoparticles in the response of BC cells to ionizing radiation by comparing 2D and 3D models. In this research, four kinds of AuNPs, different in size and PEG length, were used to sensitize cells to ionizing radiation. The in vitro viability, uptake, and reactive oxygen species generation in cells were investigated in a time- and concentration-dependent manner using 2D and 3D models. Next, after the previous incubation with AuNPs, cells were irradiated with 2 Gy. The assessment of the radiation effect in combination with AuNPs was analyzed using the clonogenic assay and γH2AX level. The study highlights the role of the PEG chain in the efficiency of AuNPs in the process of sensitizing cells to ionizing radiation. The results obtained imply that AuNPs are a promising solution for combined treatment with radiotherapy.