The evaluation of the anti-cancer drug elesclomol that forms a redox-active copper chelate as a potential anti-tubercular drug

The observations that the innate immune system employs copper to eliminate bacterial infection and that resistance to copper enhances virulence of Mycobacterium tuberculosis (Mtb) prompted us to examine the effects the anti-cancer agent elesclomol on Mtb. As a bis-thionohydrazide, elesclomol chelates with copper to form a copper complex in situ that via redox cycling of the metal ion greatly enhances oxidative stress in tumour cells. Here, we demonstrate that elesclomol is relatively potent against Mtb H37Rv with minimum inhibitory concentration of 10 μM (4 mg/L) and against multidrug resistant clinical isolates of Mtb, displays additive interactions with known tuberculosis drugs such as isoniazid and ethambutol, and a synergistic interaction with rifampicin. Controlled supplementation of elesclomol with copper in culture medium increased Mtb sensitivity by >65 fold. Overall, the activities of elesclomol in principle indicate the possibility of repurposing elesclomol or designing new thionohydrazides as potential drugs for use against Mtb. © 2019 IUBMB Life, 71(5):532-538, 2019.

Nanostructured lipid carriers (NLC) in cosmetic dermal products

The first generation of lipid nanoparticles was introduced as solid lipid nanoparticles (SLN), the second, improved generation as nanostructured lipid carriers (NLC). Identical to the liposomes, the lipid nanoparticles (NLC) appeared as products first on the cosmetic market. The article gives an overview of the cosmetic benefits of lipid nanoparticles, that means enhancement of chemical stability of actives, film formation, controlled occlusion, skin hydration, enhanced skin bioavailability and physical stability of the lipid nanoparticles as topical formulations. NLC are on the market as concentrates to be used as cosmetic excipients, special formulation challenges for these products are discussed. NLC appeared also in a number of finished cosmetic products world-wide. An overview of these products is provided including their special effects due to the lipid nanoparticles, lipids used for their production and incorporated cosmetic actives.

Modification of collagenase activity in the skin of young, adult and old rats by a plasma factor

After its stabilization during aging, collagen undergoes a certain degradation by collagenase action. Denatured collagen is degraded very fast, and that of old animals faster than that of young ones. The process is well regulated, the degradation emits signals to the cells for a new synthesis of collagen. In newly synthesized collagen the crosslinking has to begin again, therefore we may consider this collagen a "young" one. Influences upon the dermis collagen, for instance, can have an age-accelerating or-delaying effect. We put forward the question, if the possibility exists to induce the synthesis of new collagen by the action of collagenase. To do this it might be necessary to boost collagenase action using stimulators or activators, as there are for instance cytokines that are perhaps the most physiologically relevant mediators to simulate the production of collagenase. Other compounds possibly activate the already produced enzyme. We tested a bovine (calf) serum protein that is heat resistant (AB) for its activity to stimulate collagenase in vitro using the collagenase activity of homogenized skin to estimate the necessary concentrations for the stimulation in vivo. For that purpose we used H-3 labelled collagen in a system with and without the activator in various concentration.. After finding the appropriate concentration of the activator, tested with the dermis of rats aged 14 and 32 months, the shaved back skin of rats aged 9 and 21 months was treated with the activator during a time of four weeks using this concentration. As compared with the controls the dermis showed biochemical and rheological characteristics corresponding to the dermis of younger rats. We conclude that the bovine serum protein activates collagenase to such a degree that collagen turnover is vigorously accelerated. Furthermore it was also possible to cancel UV induced crosslinking of collagen in rats. Both effects might have a certain importance with respect to skin treatment.