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Urolithin A is a gut metabolite of ellagitannins and reported to confer health benefits, e.g., by increased clearance of damaged mitochondria by macroautophagy or curbed inflammation. One targeted cell type are macrophages, which are plastic and able to adopt pro- or anti-inflammatory polarization states, usually assigned as M1 and M2 macrophages, respectively. This flexibility is tightly coupled to characteristic shifts in metabolism, such as increased glycolysis in M1 macrophages, and protein expression upon appropriate stimulation. This study aimed at investigating whether the anti-inflammatory properties of U: rolithin A may be driven by metabolic alterations in cultivated murine M1(lipopolysaccharide) macrophages. Expression and extracellular flux analyses showed that urolithin A led to reduced il1β, il6 , and nos2 expression and boosted glycolytic activity in M1(lipopolysaccharide) macrophages. The pro-glycolytic feature of UROLITHIN A: occurred in order to causally contribute to its anti-inflammatory potential, based on experiments in cells with impeded glycolysis. Mdivi, an inhibitor of mitochondrial fission, blunted increased glycolytic activity and reduced M1 marker expression in M1(lipopolysaccharide/UROLITHIN A: ), indicating that segregation of mitochondria was a prerequisite for both actions of UROLITHIN A: . Overall, we uncovered a so far unappreciated metabolic facet within the anti-inflammatory activity of UROLITHIN A: and call for caution about the simplified notion of increased aerobic glycolysis as an inevitably proinflammatory feature in macrophages upon exposure to natural products., Competing Interests: The authors declare that they have no conflict of interest., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

The mucilage of RAMONDA MYCONI leaves is composed of several Polysaccharides differing in acidity due to the content of galacturonic acid. RMP-2 and RMP-4 are the most important fractions, where RMP-2 is an arabinogalactan containing galacturonic acid and rhamnose, probably connected to a protein moiety. RMP-4 is the major fraction, containing a Polysaccharide with 90% of galacturonic acid. It has a pectin-like structure and the neutral sugar enriched regions show a structure related to the rhamnogalacturonan II type.

The determination of the inhibition of PAF (platelet-activating factor)-induced platelet aggregation has been proposed as a biological standardization method for commercially available Ginkgo biloba extracts by measuring the characteristic pharmacological effect of ginkgolides in vitro. The determination is specific for ginkgolides A, B, C, and J and is not influenced by other constituents present in Ginkgo biloba extracts. IC50 values of ginkgolide B can be used to standardize various Ginkgo extracts produced by special extraction methods with respect to equi-effective ginkgolide B contents. In order to compare values obtained by a chemical-analytical procedure with those obtained by the biological assay, the equi-effective total ginkgolide content of each Ginkgo extract had to be calculated. Accordingly, the concentrations of the individual ginkgolides in the various Ginkgo extracts were determined chromatographically by assaying ginkgolides as trime-thylsilyl derivatives. Their individual contributions towards the measured in vitro effects were derived from their respective IC50 values. The calculated equi-effective total ginkgolide contents of the Ginkgo extracts were in good agreement with those obtained by gas chromatography. The results demonstrate that, in addition to a chemical standardization, the biological standardization of Ginkgo extract preparations is also feasible.

Three water-soluble polysaccharides have been isolated from flower buds of Hibiscus sabdariffa L. (HIB 1,2,3). The neutral polysaccharides (HIB 1 and 2) are composed of arabinans and arabinogalactans of low relative molecular mass. The major fraction was investigated by methylation analysis, pectinase-treatment, mild acid hydrolysis and NMR studies, and it was shown to be a pectin-like molecule (Mr = 10(5)d). The main chain is composed of alpha-1,4-linked GalA (24% methyl-esterified) and alpha-1,2-linked Rha. Side chains are built of Gal and Ara and are connected to the main chain via C-4 of every third Rha. Its structure seems to be different from polysaccharide structures described in other species of the Hibiscus genus and the Malvaceae family. All fractions were assayed for possible immune-modulating effects. All fractions showed some activity, but the main acidic fraction was contaminated with lipopolysaccharide, and therefore its shown activity has to be discussed carefully.

The procedure for allicin synthesis could be improved. The time for HPLC analysis of allicin was shortened by the application of different isocratic elution systems. Calibration was performed by use of an allicin/silica gel adsorbate as external standard and its allicin content could be confirmed by different methods. L-(+)-Alliin was synthesized and applied as external standard for the quantitative determination of alliin by HPLC. Diastereoisomers had been separated by repeated recrystallization. Fresh ALLIUM SATIVUM bulbs from different origins were analyzed with respect to allicin content after complete enzymatic conversion of alliin; allicin contents found were in the range of 0.4%. The corresponding alliin contents were in the range of 0.9%. For a comparative evaluation of the alliin- and the allicin-HPLC determination methods, commercially available garlic preparations were analyzed, demonstrating that both methods are appropriate. However, the application of the HPLC system for allicin determination, in addition to providing information on the alliin-dependent allicin-generating capacity, enables the simultaneous quantification of allicin transformation products, such as ajoenes, dithiins, and alkyl sulfides. It was found that, for quantitative GLC analysis of allicin, allicin has to be used as an external standard.

A purified alliin lyase (EC 4.4.1.4) from garlic ( ALLIUM SATIVUM L.) has been characterized by kinetic and spectral data under the addition of different substrates, inhibitors, and reducing agents. Hydroxylamine sulfate (50 microM) inhibited the alliinase activity by nearly 90%. Rotenone revealed a similar effect at a concentration of 10 nano-molar. Examination of L-cysteine, and a series of related compounds, on a competitive inhibitory effect on the alliinase-catalyzed alliin cleavage resulted in a list of essential functional groups for substances with this property. Spectral studies on the purified, yellow appearing alliinase enzyme confirmed the existance of an unknown flavinecoenzyme.

Allicin has been synthesized and was purified by liquid chromatography. HPLC chromatograms recorded at different wavelengths reveal pure allicin at similar retention times. The purity of the allicin peak could be confirmed by diode array detection. Pure synthetic allicin has been identified by infrared and mass spectrometry and its spectra were characterized. For the quantitative determination of allicin from different sources, an external standard method has been elaborated.

An alliin lyase (EC 4.4.1.4) preparation from garlic, ALLIUM SATIVUM L., has been purified to apparent homogeneity. The purification procedure involved liquid chromatography steps on hydroxylapatite, on an anion exchanger, and on a chromatofocussing medium. The enzyme protein was characterized by a relative molecular mass of 108,000, and was found to consist of two equal subunits. Its isoelectric point was determined to be 4.9. The enzyme appeared rather thermolabile. Simulated gastric-intestinal passage by a modified "half change test" revealed a high acid lability of the active alliinase protein. K (m)-values for different substrates were in the mM range, and activating energies for the cleavage of different substrates could be determined. A maximal specific activity for synthetic alliin in the range of 490 micromoles per min and mg protein could be achieved at 33 degrees C. There are some significant differences in the characterization of the purified protein compared to results previously reported by others on this enzyme.