Synthesis and investigation of anti-Toxoplasma gondii activity of novel thiazoles containing benzo [b]thiophene moiety are presented. Among the derivatives, compound 3k with adamantyl group shows exceptionally high potency against Me49 strain with IC50 (8.74 μM) value which is significantly lower than the activity of trimethoprim (IC50 39.23 μM). In addition, compounds 3a, 3b and 3k showed significant activity against RH strain (IC50 51.88-83.49 μM). The results of the cytotoxicity evaluation showed that Toxoplasma gondii growth was inhibited at non-cytotoxic concentrations for the mammalian L929 fibroblast (CC30 ∼ 880 μM). The most active compound 3k showed tyrosinase inhibition effect, with IC50 value of 328.5 μM. The binding energies calculated for compounds 3a-3e, 3k are strongly correlated with the experimentally determined values of tyrosinase inhibition activity. Moreover, the binding energies corresponding to the same ligands and calculated for both tyrosinase and tyrosine hydroxylase are also correlated with each other, suggesting that tyrosinase inhibitors may also have an inhibitory effect on tyrosine hydroxylase. Compounds 3j and 3k have also very strong antioxidant activity (IC50 15.9 and 15.5 μM), respectively, which is ten times higher than well-known antioxidant BHT.

Chitosan, a polyaminosaccharide with high medical and cosmetic potential, can be combined with the beneficial properties of glycolic acid to form a gel that not only moisturizes the skin, but also has a regenerative effect. Its involvement in the activation of biochemical processes may be associated with the activity of skin ion channels. Therefore, the aim of the research was to evaluate the immediate (15 s) and long-term (24 h) effect of chitosan–glycolic acid gel (CGG) on the transepithelial electric potential and the transepithelial electric resistance (R) of skin specimens tested in vitro. Stimulation during immediate and prolonged application of CGG to skin specimens resulted in a significant decrease in the measured minimal transepithelial electric potential (PDmin). The absence of any change in the R after the CGG application indicates that it does not affect the skin transmission, or cause distortion, microdamage or changes in ion permeability. However, the reduction in potential may be due to the increased transport of chloride ions, and thus water, from outside the cell into the cell interior. Increased secretion of chloride ions is achieved by stimulating the action of the CFTR (cystic fibrosis transmembrane conductance). It can be assumed that chitosan gently stimulates the secretion of chlorides, while maintaining a tendency to reduce the transport of sodium ions, without causing deformation or tissue damage.

Due to the lack of skin donors, the short time frame for conducting the procedure, and the increasing demand for tissue specimens, the proper storage conditions for skin fragments have gained critical importance. Therefore, the search for methods for storing skin tissue long-term, ensuring its physiological functions, is a matter of considerable interest. Freezing skin fragments in a cryoprotectant solution, such as dimethylsulfoxide (DMSO), can be a valuable complement to tissues for transplantation and for supplying difficult-to-heal wounds. This study aimed to assess the effect of deep freezing rabbit skin fragments immersed in a 5% DMSO solution on their electrophysiological parameters. Control (n = 23) and defrosted skin specimens were incubated in Ringer (n = 21), amiloride (n = 26), and bumetanide (n = 24) solutions. Then, resistance (R), potential difference (PD), and minimal and maximal PD were measured. The specimens did not show differences in R values compared to controls, which means that the skin subjected to freezing was compact and durable. However, the tissue subjected to freezing in DMSO solution presented increased transport of sodium and chloride ions, which may translate into a change in pain perception, the development of hypersensitivity and/or allergy, and the initiation of repair and regeneration processes.

Collagen is widely used in the cosmetics industry as an active ingredient in skin-care formulations due to its biocompatibility, biodegradability, low antigenicity, and high biological activity. As a natural humectant, collagen binds water molecules within the skin, reduces transepidermal water loss, and helps maintain skin elasticity and hydration. Despite its broad application, the influence of collagen on epithelial ion transport remains insufficiently understood. This study evaluated the effect of a gel containing triple-helical collagen on sodium and chloride ion transport in the isolated rabbit skin. The collagen gel was applied to 25 skin specimens for 24 h and compared with 30 untreated control specimens. Electrophysiological analyses included measurements of transepithelial electrical potential (PD), electrical resistance (R), and potential changes during stimulation (PDmin and PDmax). Collagen gel significantly decreased R compared with control tissues, indicating altered tissue permeability. Collagen gel-treated tissues also exhibited a significantly more electropositive PDmin than controls, whereas PDmax values remained comparable between groups, suggesting that electrophysiological responsiveness was maintained under the experimental conditions. The observed electropositive shift in PDmin may reflect altered sodium ion transport. Whether these electrophysiological changes are associated with changes in tissue hydration requires direct investigation.