Pharmacokinetic Study of Anti-osteoarthritic Compounds of a Standardized Fraction from Sphaeralcea Angustifolia.

Sphaeralcea angustifolia has been widely used in inflammatory conditions such as blows, bruises, fractures, and wounds. The compounds identified as active in plants and suspension cell culture of S. angustifolia were tomentin, scopoletin, and sphaeralcic acid. To consolidate the integral use of knowledge about the S. angunstifolia and strengthen its pharmacological use in patients with knee osteoarthritis, the pharmacokinetic behavior of the active compounds was characterized. The SaTSS (S. angustifoloia standardized in Tomentin, Scopoletin, and Sphaeralcic acid) anti-ostearthritic fraction was obtained from cell suspension. The analytical method of High-Performance Liquid Chromatography (HPLC) for tomentin, scopoletin, and sphaeralcic acid were validated determining the accuracy, precision linearity, sensibility, specificity, detection limits, and quantification time-range parameters, as well as extraction efficiency and stability of compounds. The pharmacokinetic assay was performed with ICR mice strain, in which the mice were administrated with a single oral or intravenous dose (400 mg/kg with 7.1 mg/kg of scopoletin and tomentin in mixture and 34.6 mg/kg of sphaeralcic acid) of the SaTSS standardized active fraction. The results of the validated analytical methods allowed establishing, in a validated manner, that a coumarin mixture and sphaeralcic acid present in the SaTES fraction were detected in plasma. According to the values of Akaike Information Criteria (AIC), Sum of Squares (SS), Schwarz Criteria (SC), and by the determination coefficient (R2), the compounds follow a two-compartment model.

Elimination pharmacokinetics of sphaeralcic acid, tomentin and scopoletin mixture from a standardized fraction of Sphaeralcea angustifolia (Cav.) G. Don orally administered.

Sphaeralcea angustifolia (Cav.) G. Don (Malvaceae) is a plant used in inflammatory illnesses. The scopoletin was the main responsible compound for the anti-arthritic effect in this species. The therapeutic effectiveness of a S. angustifolia dichloromethane extract gel standardized in scopoletin was confirmed in patients with osteoarthritis. Cells in suspension cultures from S. angustifolia were established for scopoletin production; in addition, tomentin, and sphaeralcic acid compounds were isolated from this culture. Tomentin and sphaeralcic acid showed also anti-inflammatory and immunomodulatory effects. Validation of HPLC quantification methods for sphaeralcic acid, and scopoletin and tomentin was performed in addition to extraction efficiency and stability of the active compounds. The pharmacokinetic parameters of scopoletin and tomentine in mixture, and sphaeralcic acid after oral administration of standardized active fraction indicated that these compounds followed a two-compartment model; they were bioavailable in plasma (absorbed) and distributed to blank organs. No products derived from their biotransformation were detected. The objective of this work was to determine the pharmacokinetic constants of urinary and fecal elimination in mice of the anti-arthritic compounds, after oral administration (400 mg / kg) of a standardized active fraction (SaTES) of S. angustifolia. It was established that the coumarin mixture (scopoletin and tomentin) were eliminated by the urine; while, sphaeralcic acid was mainly eliminated by fecal path, following both a non-compartmental behavior. No products derived from their biotransformation were detected.

Two-component system CbrA/CbrB controls alginate production in Azotobacter vinelandii.

Azotobacter vinelandii, belonging to the Pseudomonadaceae family, is a free-living bacterium that has been considered to be a good source for the production of bacterial polymers such as alginate. In A. vinelandii the synthesis of this polymer is regulated by the Gac/Rsm post-transcriptional regulatory system, in which the RsmA protein binds to the mRNA of the biosynthetic algD gene, inhibiting translation. In several Pseudomonas spp. the two-component system CbrA/CbrB has been described to control a variety of metabolic and behavioural traits needed for adaptation to changing environmental conditions. In this work, we show that the A. vinelandii CbrA/CbrB two-component system negatively affects alginate synthesis, a function that has not been described in Pseudomonas aeruginosa or any other Pseudomonas species. CbrA/CbrB was found to control the expression of some alginate biosynthetic genes, mainly algD translation. In agreement with this result, the CbrA/CbrB system was necessary for optimal rsmA expression levels. CbrA/CbrB was also required for maximum accumulation of the sigma factor RpoS. This last effect could explain the positive effect of CbrA/CbrB on rsmA expression, as we also showed that one of the promoters driving rsmA transcription was RpoS-dependent. However, although inactivation of rpoS increased alginate production by almost 100 %, a cbrA mutation increased the synthesis of this polymer by up to 500 %, implying the existence of additional CbrA/CbrB regulatory pathways for the control of alginate production. The control exerted by CbrA/CbrB on the expression of the RsmA protein indicates the central role of this system in regulating carbon metabolism in A. vinelandii.