Adolf Kler

Pharmacokinetics of Anthocyanidin-3-Glycosides Following Consumption of Hibiscus sabdariffa L. Extract

Pharmacokinetic parameters of several dietary anthocyanins following consumption of Hibiscus sabdariffa L. extract were determined in 6 healthy volunteers. Subjects were given a single oral dose of 150 mL of Hibiscus sabdariffa L. extract yielding 62.6 mg of cyanidin‐3‐sambubioside, 81.6 mg of delphindin‐3‐sambubioside, and 147.4 mg of total anthocyanins (calculated as cyanidin equivalents). Within 7 hours, the urinary excretion of cyanidin‐3‐sambubioside, delphinidin‐3‐sambubioside, and total anthocyanins (ie, the sum of all quantifiable anthocyanidin glycosides) was 0.016%, 0.021%, and 0.018% of the administered doses, respectively. Maximum excretion rates were determined at 1.5 to 2.0 hours after intake. The dose‐normalized plasma area under the curve estimates were 0.076, 0.032, and 0.050 ng•h/mL/mg for cyanidin‐3‐sambubioside, delphinidin‐3‐sambubioside, and total anthocyanins, respectively. The dose‐normalized Cmax estimates were 0.036, 0.015, and 0.023 ng/mL/mg in the same sequence. They were reached each at 1.5 hours (median) after intake. The geometric means of t1/2 were 2.18, 3.34, and 2.63 hours for cyanidin‐3‐sambubioside, delphinidin‐3‐sambubioside, and total anthocyanins, respectively. The urinary excretion of intact anthocyanins was fast and appeared to be monoexponential. To evaluate the contribution of anthocyanins to the health‐protecting effects of Hibiscus sabdariffa L. extract, it will be necessary to perform further studies on both the intact glycosides and their in vivo metabolites or conjugates in human plasma and urine.

Theogallin and l-theanine as active ingredients in decaffeinated green tea extract: II. Characterization in the freely moving rat by means of quantitative field potential analysis

The model Tele‐Stereo‐EEG (continuous recording of intracerebral field potentials in the freely moving rat to produce an electropharmacogram) has been used to see if l‐theanine‐ and theogallin‐enriched decaffeinated green tea extract would change electrical brain activity after oral administration, to provide proof of access of active components to the brain via the blood‐brain barrier. Baseline recording (45 min) was followed by a 5‐h recording session after oral ingestion of the extract or single components: l‐theanine, theogallin and quinic acid, a suggested metabolite of theogallin. Power spectra from Fast Fourier Transformed (FFT) field potential changes were divided into six frequency bands (delta, theta, alpha1, alpha2, beta1 and beta2). No effects could be measured using a saline solution for control purposes. Oral administration of 75 mg kg−1 total extract led to power decreases mainly in delta and alpha2 frequencies during the first hour. This pattern has been observed in the presence of stimulatory synthetic compounds. Oral administration of 30 mg kg−1 l‐theanine led to power decreases of nearly all frequencies, being more pronounced during the second and following hours in comparison with the first hour. Ingestion of 20 mg kg−1 theogallin also showed a power decreasing effect on cortical activity. Its possible metabolite quinic acid (10 mg kg−1, p.o.) also produced decreases in delta, alpha2 and beta1 frequencies. Measurement of motion resulted in an increase during the first hour in the presence of theogallin and l‐theanine. A tendential decrease was observed in the presence of l‐theanine during the last hour at its presumably highest plasma levels. The results with the administration of the total extract provided evidence for the maior involvement of l‐theanine and theogallin (or its presumable metabolite quinic acid) in its action, since no other active compounds were present in the extract. These compounds could be classified by comparison with reference drugs using discriminant analysis as being antidepressive and cognition enhancing, respectively. The extract appeared among those drugs having stimulatory effects.

Theogallin and L-theanine as active ingredients in decaffeinated green tea extract: I. electrophysiological characterization in the rat hippocampus in-vitro

The in‐vitro hippocampus slice preparation was used to mimic a physiological situation where nervous tissue is exposed directly to the water soluble extract of green tea and some of its constituents. This investigation provides evidence that L‐theanine‐ and theogallin‐enriched decaffeinated green tea extract is able to change the physiological pattern of electrical hippocampus activity in a concentration dependent manner (EC50 3 mg L−1). Of the seven fractions or single components tested (fraction containing all amino acids without L‐theanine, fractions containing all amino acids plus L‐theanine, glutamic acid, theogallin, its metabolites quinic acid and gallic acid, and L‐theanine alone), glutamic acid produced the strongest changes in terms of increased population spike amplitude after single stimuli and increased long‐term potentiation, commonly taken as representative for enhancement of spatial and time dependent memory. The presence of theogallin alone shifted the activity in the same direction. Similar results as with theogallin were obtained in the presence of quinic acid. No effect was seen with gallic acid. Opposite changes (decrease of population spike amplitude and attenuated long‐term potentiation) were observed in the presence of L‐theanine alone. No effects were detected during the addition of the amino acid mixture unless L‐theanine was added, leading to a decrease of the responses as observed for the action of L‐theanine alone. The results provide evidence for the involvement of several active principles in the action of enriched green tea extract on electrical brain activity. The overall enhancement of hippocampal pyramidal cell responses as observed for the crude extract seems to be due to the combined action of glutamic acid and theogallin (or its presumable metabolite quinic acid), whereas L‐theanine seems to have an opposite effect. However, this action was not strong enough to antagonize the effects of glutamic acid and theogallin. The results are in line with the observation that the tested green tea extract improves cognition at concomitant mental relaxation in man.

Antioxidative and antiinflammatory potential of different functional drink concepts in vitro.

The present study was undertaken to investigate the antioxidative effects of three different functional drink concepts especially designed to improve the bodys performance and function and to possess high antioxidant activities. The concepts based on the mixture of various plant ingredients were: (1) eQ – equalize your nutrient balance, brain line [acerola‐dragon fruit], (2) eQ – equalize your nutrient balance, beauty line [honey‐pepper] and (3) Lets get red [intense]. By using a cell‐based test assay, the study investigated the potential of the functional drinks to inactivate reactive superoxide anion radicals generated by inflammation‐mediating cells as well as the effect on basal metabolism of these cells (antioxidant and antiinflammatory potential). In addition, by using a cell‐free test assay the potential of the drinks to inactivate free exogenous superoxide anion radicals (scavenger effect) was investigated. The data presented here demonstrate the different radical scavenging, antioxidant and anti‐inflammatory potential of the functional drink concepts. In particular Lets get red [intense] turned out to be the most potent drink in this respect and demonstrated marked efficacy in scavenging, antioxidant and antiinflammatory action. Copyright