Mechanism of the enhancing effect of glycyrrhizin on nifedipine penetration through a lipid membrane.

The saponin glycyrrhizin from liquorice root shows the ability to enhance the therapeutic activity of other drugs when used as a drug delivery system. Due to its amphiphilic properties, glycyrrhizin can form self-associates (dimers, micelles) and supramolecular complexes with a wide range of hydrophobic drugs, which leads to an increase in their solubility, stability and bioavailability. That is why the mechanism of the biological activity of glycyrrhizin is of considerable interest and has been the subject of intensive physical and chemical research in the last decade. Two mechanisms have been proposed to explain the effect of glycyrrhizin on drug bioavailability, namely, the increase in drug solubility in water and enhancement of the membrane permeability. Interest in the membrane-modifying ability of glycyrrhizic acid (GA) is also growing at present due to its recently discovered antiviral activity against SARS-CoV-2 Bailly and Vergoten (2020) [1]. In the present study, the passive permeability of the DOPC lipid membrane for the calcium channel blocker nifedipine was elucidated by parallel artificial membrane permeability assay (PAMPA) and full atomistic molecular dynamics (MD) simulation with free energy calculations. PAMPA experiments show a remarkable increase in the amount of nifedipine (NF) permeated with glycyrrhizin compared to free NF. In previous studies, we have shown using MD techniques that glycyrrhizin molecules can integrate into the lipid bilayer. In this study, MD simulation demonstrates a significant decrease in the energy barrier of NF penetration through the lipid bilayer in the presence of glycyrrhizin both in the pure DOPC membrane and in the membrane with cholesterol. This effect can be explained by the formation of hydrogen bonds between NF and GA in the middle of the bilayer.

Effectiveness of Repeated Administration of Praziquantel with Disodium Glycyrrhizinate and Two Enantiomers of Praziquantel on Opisthorchis felineus (Rivolta, 1884).

BACKGROUND: Nowadays, it is still important to develop effective anti-opisthorchiasis agents. In this work, we tested a complex of praziquantel (PZQ) with a plant origin compound-disodium glycyrrhizinate-in the ratio 1:10 PZQ:Na2GA, containing 11-fold less of the active ingredient. Our aim was to study various ways to treat trematode Opisthorchis felineus with this complex in vitro. Additionally, an in vitro comparison of the anthelmintic action was made among racemic-PZQ, (R)-PZQ, and (S)-PZQ on juvenile and adult maritae of O. felineus. METHODS: Worms extracted from the hamsters were subjected to various regimens of administration of the complex: once a day for 3 days or three times within 1 day. Moreover, mature maritae and juvenile worms of O. felineus were subjected to the comparison the anthelmintic effectiveness of racemic-PZQ, (R)-PZQ, and (S)-PZQ. RESULTS: The O. felineus maritae that received PZQ:Na2GA (1:10) thrice within 1 day were most strongly affected by the drug. Their motility substantially decreased already on the second day after the last dose, and the percentage of live worms by the end of the experimental period was the lowest. These results indicate a cumulative anthelmintic effect of this substance under the regimen "three times within 1 day." For the first time, we report that among the three substances (racemic-PZQ and two enantiomers), (R)-PZQ has the highest anthelmintic activity, toward both juvenile and sexually mature maritae of O. felineus. CONCLUSION: These findings suggest that the development of a supramolecular complex of (R)-PZQ with disodium glycyrrhizinate and administration of this complex three times within 1 day are promising approaches.

Physicochemical Properties and Anti-Opisthorchosis Effect of Mechanochemically Synthesized Solid Compositions of Praziquantel with Glycyrrhizic Acid Disodium Salt.

The mechanochemical preparation of solid compositions of praziquantel with plant saponin (glycyrrhizic acid disodium salt) is described. The study of a number of physicochemical parameters showed that dissolving solid compositions in water is accompanied by the inclusion of praziquantel molecules into micelles, which are formed in the solution of the glycyrrhizic acid disodium salt. Using the opisthorchiasis model caused by Opisthorchis felineus, we found a 4- to 11-fold increase in the anthelmintic activity of praziquantel in the composition as compared to the official praziquantel. According to the pharmacokinetic data, the use of the composition increased the bioavailability of praziquantel 3 times.

[CLINICAL EFFICACY OF TREATMENT OF STAPHYLOCOCCAL INFECTION BY COMPOSITION OF NANOSTRUCTURED SILICON DIOXIDE AND FOSFOMYCIN.]

Clinical efficacy of a composition of nanostructuared silicon dioxide and fosfomycin in treating the skin abscess induced by Staphylococcus aureus inoculation in rabbits has been studied. It is established that the proposed composition of silicon dioxide nanoparticles and fosfomycin exhibits higher therapeutic potential in treating local purulent-septic process in skin of test animals. The therapy with this composition reduced the number of abscesses in the skin by 50% after two days of application and by 80 - 90% after five days of therapy as compared to therapy with application of chloramphenicol liniment (15.0 vs. 4.0 and 7.0 vs. 2.0, respectively).

[Efficacy of a new fenbendazole formulation produced by nanotechnology-based drug delivery system against nematodosis].

The efficacy of a new fenbendazile formulation produced by nanotechnology-based drug delivery system was investigated in45 sheep naturally infected with gastrointestinal nematodes. The formulation showed 95.6% efficacy against Nematodes spp. at a dose of 1.0 mg/kg dw of its active ingredient and 100% efficacy against other species of gastrointestinal nematodes. Given at a dose of 10 mg/kg dw, the basic drug--fenbendazole (substance) displayed 96.39 and 100% efficacy, respectively.

[Improvement of the pharmacological activity of nifedipine by mechanochemical complexation with glycyrrhizic acid].

A new water-soluble form of the calcium blocker nifedipine (NF) with glycyrrhizic acid (GA) (with molecular ratio 1:4) has been obtained by mechanochemical synthesis. Its pharmacological advantages in comparison with nifedipine were determined. An effective dose of nifedipine in complex reduced to 10 times as compared to its therapeutic dose while high antihypertensive activity preservation and pleiotropic antiarhythmic activity enhancement. This new antihypertensive and antiarhythmic agent (complex of NF:GA = 1:4) is chemically stable and safe for parenteral administration.