Svetlana A. Ivanova

Antiallergic effects of pigments isolated from green sea urchin (Strongylocentrotus droebachiensis) shells.

This study was undertaken to evaluate possible antiallergic effects of an extract of pigments from green sea urchin (Strongylocentrotus droebachiensis) shells. Effects were studied on animal models - guinea pig ileum contraction, rabbit eyes allergic conjunctivitis, and rabbit local skin irritation. The extract significantly reduced, in a dose-dependent manner, the histamine-induced contractions of the isolated guinea pig ileum with ID50 =1.2 µg/mL (in equivalents of spinochrome B), had an inhibitory effect on the model of ocular allergic inflammation surpassing the reference drug olopatadine, and did not show any irritating effect in rabbits. The extract predominantly contained polyhydroxy-1,4-naphthoquinone which would be responsible for the pharmacological activity. The active compounds of the extract were evaluated in silico with molecular docking. Molecular docking into H1R receptor structures obtained from molecular dynamic simulations showed that all spinochrome derivatives bind to the receptor active site, but spinochrome monomers fit better to it. The results of the present study suggest possibilities for the development of new agents for treating allergic diseases on the base of pigments from sea urchins shells.

Improved and validated HPTLC method for quantification of oenothein B and its use for analysis of Epilobium angustifolium L.

A selective and simplest possible high-performance TLC (HPTLC) method for quantification of oenothein B on the basis of the free gallic acid and total gallic acid content after acid hydrolysis has been developed and used for analysis of cultivated Epilobium angustifolium. HPTLC of aqueous extracts of E. angustifolium was performed on silica gel with benzene-methanol-acetic acid 90:16:8 (v/v), as mobile phase. Quantitative evaluation of the plate was performed at 570 nm after derivatization with 1% ethanolic FeCl3 solution. The method was validated for precision, repeatability, and accuracy. Average recovery of the active ingredient from the samples was in the range 95.43–104.57%. The calibration plots were linear in the range 440–2200 ng per band. The technique was used, for the first time, for estimation of the oenothein B content of cultivated E. angustifolium, The oenothein B content was highest at budding time (18.4–20.2 mg g−1) and decreased dramatically to 1.0 mg g−1 after flowering.

Bioavailability of boswellic acids: in vitro/in vivo correlation

Extract of Boswellia sacra (incense tree), the main active components of which are boswellic acids, is used for the treatment of rheumatoid arthritis and gout. Boswellic acids suppress leukotriene biosynthesis in neutrophilic granulocytes by non-redox, noncompetitive inhibition of 5-lipoxygenase. Representing pentacyclic triterpenoids, boswellic acids are characterized by poor solubility in water and are highly lipophilic (1og P = 7–10.3). Bioavailability of the B. sacra (BS) extract has been studied using a new method developed for estimating and predicting the possible absorption of medicinal substances in vivo, which is based on the establishment of a correlation between the data obtained in vivo and in vitro. The validity and applicability of the proposed method is demonstrated. Release of four individual boswellic acids from BS extract has been studied in vitro using a nonconventional two-phase system simulating conditions in the gastrointestinal tract. Based on these data, the dissolution rate constants of boswellic acids have been calculated. In addition, the parameters of pharmacokinetics of ketoacids in vivo have been determined and a correlation between these parameters and the rate of release in vitro has been studied. It is established that there is a strong correlation between the results obtained in vivo and the dissolution of boswellic acids in the model two-phase medium in vitro, which makes possible prediction of the pharmacokinetic profiles of individual acids upon per os administration of BS extract.

Pharmacokinetics of curcuminoids contained in the phytopreparation arthroflex

Curcuminoids are the main active components in the extract of curcuma roots (Curcuma longa), which is widely used as an anti-inflammatory agent. We have studied the bioavailability and determined the pharmacokinetic parameters of curcuminoids contained in the complex phytopreparation Arthroflex studied experimentally in vitro and in vivo. The release of curcuminoids from Arthroflex into a nonconventional biphase system modeling conditions in the gastrointestinal tract was investigated in vitro and the dissolution rate constants were calculated. The pharmacokinetics of curcuminoids was investigated in vivo. It was established that curcumin in the initial form was missing from the blood plasma, and only two metabolites of curcuminoids were found by thin layer chromatography. The pharmacokinetic parameters of the major metabolite were determined.