Effect of green tea extracts on liver functions in Wistar rats.

An herbal medicinal product (Exolise) containing as active ingredient an hydro-alcoholic extract of green tea named AR25 (standardized to 25% catechins) has been implicated in hepatic failures, leading to the withdrawal of the marketing authorization. The active ingredient of Exolise being manufactured with 80% ethanol, the question to know whether the extraction solvent could introduce some toxic components was hypothesized. Two investigations were conducted in Wistar rats to determine if repeated oral administration of different green tea extracts could corroborate the reported hepatotoxicity in humans. In a preliminary 6 week-study, experimental groups (n=9/group) received either the vehicle or a methylene chloride extract (2500 mg/kg body weight) where potential non-polar hepatotoxin(s) could be concentrated. In a second experiment (12 week-study), rats were divided in three groups (n=10/group) and treated with either the vehicle, or an aqueous extract (1400 mg/kg) or AR25 green tea extract (2000 mg/kg). Rat liver functions were assessed by serum biochemistry of hepatotoxicity markers. No sign of evidence of characteristic hepatotoxicity was found in rats treated with very high amount of different green tea extracts in these two experiments (respectively a daily dosage, which was about 900 and 80 times higher to the therapeutic daily dosage of Exolise.

Toxicity of green tea extracts and their constituents in rat hepatocytes in primary culture.

Recent reports on sporadic cases of liver disorders (acute hepatitis, icterus, hepatocellular necrosis) after ingestion of dietary supplements based on hydro-alcoholic extracts from green tea leaves led to restrictions of the marketing of such products in certain countries of the EU. Since green tea is considered to exert a number of beneficial health effects, and, therefore, green tea products are widely used as dietary supplements, we were interested in the possible mechanism of hepatotoxicity of green tea extracts and in the components involved in such effects. Seven hours after seeding on collagen, rat hepatocytes in primary culture were treated with various hydro-alcoholic green tea extracts (two different native 80% ethanolic dry extracts and an 80% ethanolic dry extract cleared from lipophilic compounds). Cells were washed, and reduction of resazurin, used as a viability parameter monitoring intact mitochondrial function, was determined. It was found that all seven green tea extracts examined enhanced resazurin reduction significantly at a concentration range of 100-500 microg/ml medium, while a significant decrease was observed at 1-3mg/ml medium. Decreased levels were concomitant with abundant necrosis as observed by microscopic inspection of the cultures and with increased leakage of lactate dehydrogenase activity from the cells. In a separate series of experiments, the green tea constituents (-)-epicatechin, (-)-epigallocatechin-3-gallate, caffeine and theanine were tested at concentrations reflecting their levels in a typical green tea extract. Synthetic (+)-epigallocatechin (200 microM) was used for comparison. Cytotoxicity was found with (-)-epigallocatechin-3-gallate only. The concomitant addition of 0.25 mM ascorbate/0.05 mM alpha-tocopherol had no influence on cytotoxicity. In conclusion, our results suggest that high concentrations of green tea extract can exert acute toxicity in rat liver cells. (-)-Epigallocatechin-3-gallate seems to be a key constituent responsible for this effect. The relatively low bioavailability of catechins reported after oral exposure to green tea argues, however, against a causal role of these constituents in the reported liver disorders.

[Hydroxycinnamic acid levels of various batches from mugwort flowering tops]. / Teneur en acides hydroxycinnamiques de différents lots de sommités fleuries d'armoise.

Dried flowering tops of 24 harvested batches (Artemisia vulgaris: 13; Artemisia verlotiorum: 11) and 12 batches of mugwort from commercial origin were examined. The levels of principal compounds averaged respectively: total hydroxycinnamic acids 6.09; 10.29 and 9.13%, chlorogenic acid 0.79; 2.05 and 1.35%, 1,5-dicaffeoylquinic acid 0.51; 4.01 and 1.25%, 3,5-dicaffeoylquinic acid 2.21; 1.25 and 2.60%. Specifications were discussed for an European Pharmacopoeial monography.

Four steroidal alkaloids from the leaves of Buxus sempervirens.

Four new steroidal alkaloids, N20-formylbuxaminol E [(20S)-16alpha-hydroxy-20-(formylamino)-3beta-(dimethylamino)-9,10 -seco-buxa-9(11),10(19)-diene] (1), O16-syringylbuxaminol E [(20S)-16alpha-syringoyl-3beta-(dimethylamino)-20-(amino)-9, 10-seco-buxa-9(11),10(19)-diene] (2), N20-acetylbuxamine G [(20S)-20-(acetylamino)-3beta-(methylamino)-9,10-seco-buxa-9(11),1 0(19)-diene] (3) and N20-acetylbuxamine E [(20S)-20-(acetylamino)-3beta-(dimethylamino)-9,10-seco-buxa-9(11) ,10(19)-diene] (4) were isolated from the leaves of Buxus sempervirens. Their structures were determined mainly on the basis of 2D NMR studies.

Efficacy and tolerance of Harpagophytum procumbens versus diacerhein in treatment of osteoarthritis.

In a double-blind, randomized, multicentre clinical study, the efficacy and tolerance of a herbal medicine product, Harpadol (6 capsules/day, each containing 435 mg of powdered cryoground powder Harpagophytum procumbens), was compared with diacerhein 100 mg/day in the treatment, for 4 months, of 122 patients suffering from osteoarthritis of the knee and hip. Assessments of pain and functional disability were made on a 10 cm horizontal visual analogue scale; severity of osteoarthritis was evaluated by Lequesne's index. Spontaneous pain showed a significant improvement during the course of the study and there was no difference in the efficacy of the two treatments. Similarly, there was a progressive and significant reduction in the Lequesne functional index and no statistical difference was found between Harpadol and diacerhein. At completion of the study, patients taking Harpadol were using significantly less NSAIDs and antalgic drugs. The frequency of adverse events was significantly lower in the Harpadol group. The most frequent event reported was diarrhea, occurring in 8.1% and 26.7% of Harpadol and diacerhein patients respectively. The global tolerance assessment by patients at the end of treatment favoured Harpadol. The results of this study demonstrate that Harpadol is comparable in efficacy and superior in safety to diacerhein.

Efficacy and safety of Buxus sempervirens L. preparations (SPV(30)) in HIV-infected asymptomatic patients: a multicentre, randomized, double-blind, placebo-controlled trial.

The objective of the present study was to compare the efficacy and safety of two doses of SPV(30) in HIV asymptomatic patients. The study was designed as a randomized double-blind multicentre trial of two doses of SPV(30) (990 mg/d and 1980 mg/d) versus placebo. 145 previously untreated subjects with asymptomatic HIV infection (CDC group IV) and CD4 cell counts between 250 and 500 × 10(6)/1 were recruited. There was a statistically significant difference in therapeutic failures between groups in favor of SPV(30) 990 mg including decreases of CD4 cell count < 200 × 10(6)/1 and/or number of clinical aggravations (progression to AIDS or AIDS related complex). The treatment groups differed statistically in the rate of disease progression also in favor of SPV(30) 990 mg/d. Fewer patients receiving SPV(30) 990 mg/d had at the end an increase of viral load greater than 0.5 log (P = 0.029). No severe side-effects were reported in the 3 groups. From these results we conclude that SPV(30) 990 mg/d has beneficial effects in HIV asymptomatic patients and appears to delay the progression of HIV disease.

[Determination of saponosides from Panax ginseng C.A. Meyer. Comparison of official methods and HPLC]. / Dosage des saponosides de Panax ginseng C.A. Meyer. Comparison entre les méthodes officielles et la CLHP.

Official methods for determination of ginsenosides of the French and Helvetic Pharmacopoeias have been compared with HPLC method. Sample preparation schemes used are those of monographs with conventional solvent extraction and solid phase extraction with a polar and a non-polar sorbents, respectively kieselguhr and C 18 octadecyl. Liquid-solid sample clean-up with C 18 cartridge is the most effective procedure. Prior HPLC method, an hydrolysis step of malonylginsenosides is necessary. Very selective extraction resulting in highly purified solution authorizes reliable and rapid colorimetric determination from ginseng saponosides.