1,8-cineole (eucalyptol): A versatile phytochemical with therapeutic applications across multiple diseases

1,8-cineole (Eucalyptol), a naturally occurring compound derived from botanical sources such as eucalyptus, rosemary, and camphor laurel, has a long history of use in traditional medicine and exhibits an array of biological properties, including anti-inflammatory, antioxidant, antimicrobial, bronchodilatory, analgesic, and pro-apoptotic effects. Recent evidence has also indicated its potential role in managing conditions such as Alzheimer's disease, neuropathic pain, and cancer. This review spotlights the health advantages of 1,8-cineole, as demonstrated in clinical trials involving patients with respiratory disorders, including chronic obstructive pulmonary disease, asthma, bronchitis, and rhinosinusitis. In addition, we shed light on potential therapeutic applications of 1,8-cineole in various conditions, such as depression, epilepsy, peptic ulcer disease, diarrhea, cardiac-related heart diseases, and diabetes mellitus. A comprehensive understanding of 1,8-cineole's pharmacodynamics and safety aspects as well as developing effective formulations, might help to leverage its therapeutic value. This thorough review sets the stage for future research on diverse health benefits and potential uses of 1,8-cineole in tackling complex medical conditions.

Determination of orally administered 1,8-Cineol in nasal polyp tissues from chronic rhinosinusitis patients using gas chromatography: mass spectrometry

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disease causing considerable disease burden. The anti-inflammatory monoterpene 1,8-Cineol is a natural plant-based therapeutic agent that is well established to treat chronic and acute airway diseases. Aim of this study was to investigate whether the herbal drug 1,8-Cineol reaches the nasal tissue via the gut and the blood stream upon its oral administration. A highly sensitive gas chromatography mass spectrometry-based method with stir bar sorptive extraction (SBSE) for sample preparation has been developed and validated for the extraction, detection and quantification of 1,8-Cineol in tissue samples of nasal polyps from 30 CRSwNP patients. Data revealed a highly sensitive detection of 1,8-Cineol in nasal tissue samples after 14 days of oral administration of 1,8-Cineol prior to surgical treatment. There was no significant correlation between the measured 1,8-Cineol concentrations and bodyweight or BMI values of the analyzed patients, respectively. Our data indicate a systemic distribution of 1,8-Cineol in the human body after its oral administration. Individual differences in terms of metabolic characteristics and have to be further investigated. The study increases our understanding of the systemic effects of 1,8-Cineol upon its therapeutic application and benefit in patients with CRSwNP.

St. John's wort extract LI160 for the treatment of depression with atypical features - a double-blind, randomized, and placebo-controlled trial

Preliminary data suggest that hypericum extract LI160 is effective in atypical depression. Reported is the outcome of an 8-week double-blind, placebo-controlled, randomized trial of 600 mg LI160 vs. placebo in patients with vegetative features of atypical depression, i.e. hyperphagia or hypersomnia. One-hundred (100) patients with mild and 100 patients with moderate severity of a major depression according to ICD-10 were randomized. Patients needed to meet a score of 2 in at least one of the items 22-26 of the Hamilton-Depression-Rating-Scale (HAM-D) 28-item version and episode duration of at least 3 months. The primary outcome variable was the relative change of the HAM-D(17) from Baseline. Secondary outcome variables were the depression sub-score of the Patient Health Questionnaire (PHQ-9), the Clinical Global Impression (CGI), a patient's satisfaction scale, the Hamilton-Anxiety-Scale (HAM-A) and the sum score of atypical vegetative symptoms of the HAM-D(28). The percentage reduction of the HAM-D(17) for LI160 compared to placebo approached statistical significance (p=0.051) in the Full Analysis Set (FAS)-population. Using the conventional criterion of the absolute reduction of the HAM-D(17) significance was achieved (p<0.05). No significant benefit could be observed for the sum score of the atypical vegetative items of the HAM-D(28;) however, the sum score of the hypersomnia items (items 22-24) showed a significant superiority for LI160. The HAM-A, PHQ-9, and CGI-I scales demonstrated superiority of LI160 (p<0.01). Confining the analysis to moderately depressed patients, a highly significant benefit for the primary outcome variable was revealed. The study supports the beneficial effect of LI160 in depression with atypical features and the validity of the definition of atypical depression on the basis of reversed vegetative signs. Further, it identifies the PHQ-9 as a useful outcome variable in this population.

Effect of two artichoke extracts (36_U and 36_EB) on rat ileum (with respect to bowel syndrome) and the peristaltic threshold

The diagnosis and treatment of irritable bowel syndrome (IBS) are complicated. Artichoke extracts are well known to be helpful in various gastrointestinal disorders. A hydrophilic extract 36_U mainly containing luteolin-7-glycoside, luteolin-7-O-glucoside, small amounts of cynarin and luteolin increased contraction of rat ileum. This is mainly mediated by 5-HT(3) - and 5-HT(2) receptors but not 5-HT(4) receptors as can be derived by using specific antagonists such as tropisetrone, GR113806 and ketanserine. Additional mechanisms (receptors) are involved since the combination of these three antagonists was not able to fully prevent the contractive effect of extract 36_U. The lipophilic extract 36_EB mainly containing cynarin, luteolin including its glycosides, and cholorogenic acid in contrast to extract 36_U had a relaxing effect which could hardly be washed out. It was diminishing a serotonin effect and was not modified by ACh or substance P. The peristaltic threshold, i.e. the distension necessary for inducing a pathophysiologically relevant propulsion activity, is one of the important features being correlated with IBS. The peristaltic threshold was decreased by both serotonin and extract U_36. From the data it can be derived that the extract 36_U may be useful in IBS combined with obstipation when gastrointestinal contraction is necessary, whereas 36_EB may be useful in IBS combined with diarrhea when gastrointestinal relaxation is desired. Especially interesting are the influence on the threshold. It would be interesting to know which effects are mediated via cynarin and luteolin or its glycosides.

Skin tolerance of a new bath oil containing St. John's wort extract

BACKGROUND

Dry and atopic skin requires skin care with lipid-rich emollients and moisturizing bath or shower oils. However, it has been shown recently that some bath oils may even impair the skin barrier.

OBJECTIVE

To investigate the skin-irritating potential of a new bath oil containing a lipophilic St. John's wort (Hypericum perforatum) extract.

METHODS

In this single-center, randomized, double-blind, prospective study, 3 bath oils together with positive and negative controls were applied under occlusion on test areas on the volar forearms of 18 volunteers (visit 1). After 24 h, the tapes were removed, and the test areas were evaluated by a visual score and the instrumental measurement of skin erythema and transepidermal water loss (TEWL) using a Mexameter and a Tewameter (visit 2). The test substances were applied a second time, and the measurements were performed after another 24 h (visit 3).

RESULTS

The positive control, 1% vol/vol sodium lauryl sulfate (SLS), caused a significant increase in skin erythema and TEWL. In contrast, distilled water as a negative control did not influence these parameters. The new bath oil containing St. John's wort extract and 1 of the other 2 commercial products were not different from the water control. The third bath oil displayed a skin-irritating effect similar to SLS.

CONCLUSION

The results of this study confirm the different skin-irritating potential of bath oils and demonstrate good skin tolerance of the new bath oil containing St. John's wort extract.

Self medication with St. John's wort in depressive disorders: an observational study in community pharmacies

BACKGROUND

Depressive disorders are frequent. They are frequently unrecognised or sufferers use self help or self medication, e.g. with St. John's wort (SJW), instead of seeking professional help. The purpose of this study is to examine patients who buy SJW for the treatment of depression.

METHODS

In pharmacies from all over Germany customers who bought SJW and the pharmacists were asked to fill in a questionnaire on the cause for buying SJW, their health status and the type of counselling they received.

RESULTS

588 individuals were included, 293 purchased SJW as an OTC preparation, 230 had a prescription (65 missing answers). The majority in both groups were women (78.8% in OTC group, 74.3% in prescription group. Self medication patients were significantly younger. Subjects with a prescription took SJW longer (26.99+/-26.84 vs. 15.25+/-20.84 months). Both groups did not differ in self rated symptoms of depression (severity of depression, anxiety, endurance).

LIMITATIONS

No standardized interviews were used to establish the diagnosis of depression.

CONCLUSIONS

Patients who buy SJW for self medication report pronounced and persistent depressive symptoms. As this is a large group of patients they should get more attention in research. Pharmacists are the only professionals who come in contact with these patients and should therefore be considered as an important group of carers.

Hypericum extract reverses S-ketamine-induced changes in auditory evoked potentials in humans - possible implications for the treatment of schizophrenia

BACKGROUND

Auditory evoked potentials (AEP) provide a correlate of cognitive dysfunction in schizophrenia. Both cognitive dysfunction and AEP-characteristics might be related to reduced glutamatergic neurotransmission as induced by glutamate-antagonist like ketamine. Hypericum extract LI160 has demonstrated a ketamine-antagonising effect. We examined whether LI160 reverses changes of a low dose ketamine on AEP in healthy subjects.

METHODS

We performed a double-blind randomized treatment with either 2 x 750 mg LI 160 or placebo given one week, using a crossover design, in 16 health subjects. A test-battery including AEPs, the oculodynamic test (ODT) and a cognitive test were performed before and after an infusion with 4 mg of S-ketamine over a period of 1 hour.

RESULTS

S-ketamine lead to a significant decrease in the N100-P200 peak to peak (ptp) amplitude after the placebo treatment, whereas ptp was significantly increased by S-ketamine infusion in the LI160 treated subjects. The ODT and the cognitive testing revealed no significant effect of ketamine-infusion and therefore no interaction between treatment groups.

CONCLUSIONS

AEP measures are sensitive means to assess the effect of low dose ketamine. Provided that ketamine mimics cognitive deficits in schizophrenia, LI160 might be effective to treat these symptoms.

Mode of action of gingerols and shogaols on 5-HT3 receptors: binding studies, cation uptake by the receptor channel and contraction of isolated guinea-pig ileum

Ginger (rhizomes of Zingiber officinale) has been shown to exert potent anti-emetic properties, but its mode of action has not yet been elucidated. Among its active constituents, [6]-, [8]- and [10]-gingerol as well as [6]-shogaol were shown in different in vivo studies to be at least partly responsible for the drug's anti-emetic properties. In an attempt to gain more insight into the mode of action of these compounds, three different in vitro models were used to investigate their effects on 5-HT(3) receptors (serotonin receptor subtype) in more detail: [(14)C]guanidinium influx into N1E-115 cells which express 5-HT(3) receptors, isotonic contractions of the isolated guinea-pig ileum and equilibrium competition binding studies using a radioactively labeled 5-HT(3) receptor antagonist ([(3)H]GR65630) (3-(5-methyl-1H-imidazol-4-yl)-1-(1-methyl-1H-indol-3-yl)-1-propanone). All four compounds inhibited the [(14)C]guanidinium influx through 5-HT(3) receptor channels as well as contractions of the guinea-pig ileum induced by SR57227A ((4-amino)-(6-chloro-2-pyridyl)l-piperidine hydrochloride), a highly selective 5-HT(3) receptor agonist. Both effects were concentration-dependent, with the following order of potency for both models: [6]-shogaol> or =[8]-gingerol>[10]-gingerol> or =[6]-gingerol. All compounds showed also weak anticholinergic and antineurokininergic activities in the guinea-pig ileum (acetylcholine and substance P are mediators of the 5-HT(3) receptor effect). The vanilloid receptor did not seem to be involved derived from experiments using capsazepine. None of the tested ginger substances, however, was able to displace [(3)H]GR65630 from its binding site (5-HT(3) receptor) neither on intact N1E-115 cells nor on the purified membranes of HEK-293 cells over-expressing the h5-HT(3) receptor. It may be concluded that [6]-, [8]-, [10]-gingerol and [6]-shogaol exert their anti-emetic effect at least partly by acting on the 5-HT(3) receptor ion-channel complex, probably by binding to a modulatory site distinct from the serotonin binding site. This may include indirect effects via receptors in the signal cascade behind the 5-HT(3) receptor channel complex such as substance P receptors and muscarinic receptors; this needs further investigation since ginger is effective against motion sickness which is cured by some vanilloids and by anticholinergics such as scopolamine.

5-HT3 receptor blocking activity of arylalkanes isolated from the rhizome of Zingiber officinale

Different extracts (ethanolic, hexane, aqueous) of ginger (rhizomes of Zingiber officinale) and the essential oil were tested using [14C]guanidinium influx into N1E-115 cells and the isolated rat ileum in order to identify their activity in inhibiting 5-HT3 receptor function. The hexane extract proved to be the most active and yielded upon bioassay-guided fractionation nine constituents: [6]-, [8]-, [10]-gingerols, [6]- and [8]-shogaols which were previously shown as active in vivo against cytotoxic drug-induced emesis; [4]-gingerol, [6]-gingerdiol, diacetyl-[6]-gingerdiol and [6]-dehydrogingerdione have not been previously tested for anti-emetic or 5-HT3 receptor antagonistic effects. Even though the latter four compounds are only minor constituents, their identification contributed towards the characterisation of a structure-activity relationship of this class of compounds. The order of potency for the nine constituents in the N1E-115 cell system was [6]-gingerdiol approximately diacetyl-[6]-gingerdiol approximately [6]-dehydrogingerdione approximately [6]-shogaol > or = [8]-shogaol approximately [8]-gingerol > [10]-gingerol > or = [6]-gingerol > [4]-gingerol.

[Inhibition of arteriosclerotic plaque development by garlic]

OBJECTIVE

In an in vitro biosensor model (PCT/EP 97/05212), the interplay between different lipoproteins in arteriosclerotic nanoplaque formation, as well as aqueous garlic extract (0.2-5.0 g/l from LI 111 powder) as a possible candidate drug against arterio/atherosclerosis were tested within the frame of a high throughput screening.

METHODS

The processes described below were studied by ellipsometric techniques quantifying the adsorbed amount (nanoplaque formation) and layer thickness (nanoplaque size). A thorough description of the experimental setup has been given previously.

RESULTS

Proteoheparan sulfate (HS-PG) adsorption to hydrophobic silica was monoexponential and after approximately 30 min constant. The LDL plasma fraction (100 mg/dl) from a healthy probationer showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. Aqueous garlic extract (GE), preferably in a concentration of 1 g/l, applied acutely in the experiment, markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. In a normal blood Ca2+ concentration of 2.52 mmol/l, the garlic induced reduction of nanoplaque formation and molecular size amounted to 14.8 % and 3.9%, respectively, as compared to the controls. Furthermore, after ternary complex build-up, GE similar to HDL, was able to reduce nanoplaque formation and size. The incubation time for HDL and garlic was only 30 min each in these experiments. Nevertheless, after this short time the deposition of the ternary complex decreased by 6.2% resp. 16.5%, i.e. the complex aggregates were basically resolvable.

CONCLUSIONS

These experiments clearly proved that garlic extract strongly inhibits Ca2+ binding to HS-PG. In consequence, the formation of the ternary HS-PG/LDL/Ca2+ complex, initially responsible for the 'nanoplaque' composition and ultimately for the arteriosclerotic plaque generation, is decisively blunted.

Bioavailability and pharmacokinetics of caffeoylquinic acids and flavonoids after oral administration of Artichoke leaf extracts in humans

Extracts from artichoke leaves are traditionally used in the treatment of dyspeptic and hepatic disorders. Various potential pharmacodynamic effects have been observed in vitro for mono- and dicaffeoylquinic acids (e.g. chlorogenic acid, cynarin), caffeic acid and flavonoids (e.g. luteolin-7-O-glucoside) which are the main phenolic constituents of artichoke leaf extract (ALE). However, in vivo not only the genuine extract constituents but also their metabolites may contribute to efficacy. Therefore, the evaluation of systemic availability of potential bioactive plant constituents is a major prerequisite for the interpretation of in vitro pharmacological testing. In order to get more detailed information about absorption, metabolism and disposition of ALE, two different extracts were administered to 14 healthy volunteers in a crossover study. Each subject received doses of both extracts. Extract A administered dose: caffeoylquinic acids equivalent to 107.0 mg caffeic acid and luteolin glycosides equivalent to 14.4 mg luteolin. Extract B administered dose: caffeoylquinic acids equivalent to 153.8 mg caffeic acid and luteolin glycosides equivalent to 35.2 mg luteolin. Urine and plasma analysis were performed by a validated HPLC method using 12-channel coulometric array detection. In human plasma or urine none of the genuine target extract constituents could be detected. However, caffeic acid (CA), its methylated derivates ferulic acid (FA) and isoferulic acid (IFA) and the hydrogenation products dihydrocaffeic acid (DHCA) and dihydroferulic acid (DHFA) were identified as metabolites derived from caffeoylquinic acids. Except of DHFA all of these compounds were present as sulfates or glucuronides. Peak plasma concentrations of total CA, FA and IFA were reached within 1 h and declined over 24 h showing almost biphasic profiles. In contrast maximum concentrations for total DHCA and DHFA were observed only after 6-7 h, indicating two different metabolic pathways for caffeoylquinic acids. Luteolin administered as glucoside was recovered from plasma and urine only as sulfate or glucuronide but neither in form of genuine glucosides nor as free luteolin. Peak plasma concentrations were reached rapidly within 0.5 h. The elimination showed a biphasic profile.

The effect of garlic on arteriosclerotic nanoplaque formation and size

OBJECTIVE

In an in vitro biosensor model (PCT/EP 97/05212), the interplay between different lipoproteins in arteriosclerotic nanoplaque formation, as well as aqueous garlic extract (0.2-5.0 g/l from LI 111 powder) as a possible candidate drug against arterio/atherosclerosis were tested within the frame of a high throughput screening.

METHODS

The processes described below were studied by ellipsometric techniques quantifying the adsorbed amount (nanoplaque formation) and layer thickness (nanoplaque size). A thorough description of the experimental setup has been given previously.

RESULTS

Proteoheparan sulfate (HS-PG) adsorption to hydrophobic silica was monoexponential and after approximately 30 min constant. The addition of 2.52 mmol/l Ca2+ led to a further increase in HS-PG adsorption because Ca2+ was bound to the polyanionic glycosaminoglycan (GAG) chains thus screening their negative fixed charges and turning the whole molecule more hydrophobic. Incubation with 0.2 g/l aqueous garlic extract (GE) for 30 min did not change the adsorption of HS-PG. However, the following addition of Ca2+ ions reduced the increase in adsorption by 50.8% within 40 min. The adsorption of a second Ca2+ step to 10.08 mmol/l was reduced by even 82.1% within the next 40 min. Having detected this inhibition of receptor calcification, it could be expected that the build-up of the ternary nanoplaque complex is also affected by garlic. The LDL plasma fraction (100 mg/dl) from a healthy probationer showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. GE, preferably in a concentration of 1 g/l, applied acutely in the experiment, markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. In a normal blood Ca2+ concentration of 2.52 mmol/l, the garlic induced reduction of nanoplaque formation and molecular size amounted to 14.8% and 3.9%, respectively, as compared to the controls. Furthermore, after ternary complex build-up, GE similar to HDL, was able to reduce nanoplaque formation and size. The incubation time for HDL and garlic was only 30 min each in these experiments. Nevertheless, after this short time the deposition of the ternary complex decreased by 6.2% resp. 16.5%, i.e. the complex aggregates were basically resolvable.

CONCLUSIONS

These experiments clearly proved that garlic extract strongly inhibits Ca2+ binding to HS-PG. In consequence, the formation of the ternary HS-PG/LDL/Ca2+ complex, initially responsible for the 'nanoplaque' composition and ultimately for the arteriosclerotic plaque generation, is decisively blunted.

Efficacy and tolerability of valerian extract LI 156 compared with oxazepam in the treatment of non-organic insomnia--a randomized, double-blind, comparative clinical study

Patients aged 18 to 73 years and diagnosed with non-organic insomnia according to ICD-10 (F 51.0) were treated in a multicentre, double-blind, randomised parallel group comparison with either 600 mg/die valerian extract LI 156 (Sedonium) or 10 mg/die oxazepam taken for 6 weeks. A total of 202 outpatients with a mean duration of insomnia of 3.5 months at baseline were included at 24 study centres (general practices) in Germany. - Sleep quality (SQ) after 6 weeks measured by the Sleep Questionnaire B (SF-B; CIPS 1996) showed that 600 mg/die valerian extract LI 156 was at least as efficacious as a treatment with 10 mg/die oxazepam. Both treatments markedly increased sleep quality compared with baseline (p <0.01). The other SF-B subscales, i.e. feeling of refreshment after sleep (GES), psychic stability in the evening (PSYA), psychic exhaustion in the evening (PSYE), psychosomatic symptoms in the sleep phase (PSS), dream recall (TRME), and duration of sleep confirmed similar effects of both treatments. Clinical Global Impressions scale (CGI) and Global Assessment of Efficacy by investigator and patient, again, showed similar effects of both treatments. Adverse events occurred in 29 patients (28.4%) receiving valerian extract LI 156 and 36 patients (36.0%) under oxazepam, and were all rated mild to moderate. No serious adverse drug reactions were reported in either group. Most patients assessed their respective treatment as very good (82.8% in the valerian group, 73.4% in the oxazepam group). During the 6 week treatment phase Valerian extract LI 156 (Sedonium) 600 mg/die showed a comparable efficacy to 10 mg/die oxazepam in the therapy of non-organic insomnia.

Use of metoprolol CR/XL to maintain sinus rhythm after conversion from persistent atrial fibrillation: a randomized, double-blind, placebo-controlled study

OBJECTIVES

The primary objective of the present study was to assess the efficacy of metoprolol CR/XL to reduce the risk of relapse after cardioversion of persistent atrial fibrillation to sinus rhythm.

BACKGROUND

Indirect data from studies with d,l sotalol provide evidence that the beta-blocking effects of the compound are important in maintaining sinus rhythm after cardioversion of atrial fibrillation.

METHODS

After successful conversion to sinus rhythm, 394 patients with a history of persistent atrial fibrillation were randomly assigned to treatment with metoprolol CR/XL or placebo. The two treatment groups were similar with respect to all pretreatment characteristics. Patients were seen on an outpatient basis for recording of resting electrocardiogram (ECG) after one week, one, three and six months of follow-up or whenever they felt that they had a relapse into atrial fibrillation or experienced an adverse event.

RESULTS

In the metoprolol CR/XL group, 96 patients (48.7%) had a relapse into atrial fibrillation compared with 118 patients (59.9%) in the placebo group (p = 0.005). Heart rate in patients after a relapse into atrial fibrillation was significantly lower in the metoprolol group (98 +/- 23 beats/min) than in the placebo group (107 +/- 27 beats/min). The rate of adverse events reported was similar in both groups when the difference in follow-up time was taken into account.

CONCLUSIONS

The results of this double-blind, placebo-controlled study in patients after cardioversion of persistent atrial fibrillation showed that metoprolol CR/XL was effective in preventing relapse into atrial fibrillation or flutter.

Single-dose and steady-state pharmacokinetics of hypericin and pseudohypericin

Single-dose and steady-state pharmacokinetics of antivirally acting hypericin (H) and pseudohypericin (PH) were studied in 13 healthy volunteers by administration of St. John's Wort extract LI 160, a plantal antidepressant. Oral administration of 250, 750, and 1,500 micrograms of H and 526, 1,578, and 3,156 micrograms of PH resulted in median peak levels in plasma (Cmax) of 1.3, 7.2, and 16.6 micrograms/liter for H and 3.4, 12.1, and 29.7 micrograms/liter for PH, respectively. The Cmax and the area under the curve values for the lowest dose were disproportionally lower than those for the higher doses. A lag time of 1.9 h for H was remarkably longer than the 0.4-h lag time for PH. Median half-lives for absorption, distribution, and elimination were 0.6, 6.0, and 43.1 h after 750 micrograms of H and 1.3, 1.4, and 24.8 h after 1,578 micrograms of PH, respectively. Fourteen-day treatment with 250 micrograms of H and 526 micrograms of PH three times a day resulted in median steady-state trough levels of 7.9 micrograms/liter for H and 4.8 micrograms/liter for PH after 7 and 4 days, respectively; the corresponding Cssmax levels were 8.8 and 8.5 micrograms/liter, respectively. Kinetic parameters after intravenous administration of Hypericum extract (115 and 38 micrograms for H and PH, respectively) in two subjects corresponded to those estimated after an oral dosage. Both H and PH were initially distributed into a central volume of 4.2 and 5.0 liter, respectively. The mean distribution volumes at steady state were 19.7 liters for H and 39.3 liters for PH, and the mean total clearance rates were 9.2 ml/min for H and 43.3 ml/min for PH. The systemic availability of H and PH from LI 160 was roughly estimated to be 14 and 21%, respectively. Treatment with Hypericum extract, even in high doses, was well tolerated.

Modulation of cytokine expression by hypericum extract

The effect of hypericum extract LI 160 on the stimulated cytokine expression was investigated in vitro in a whole blood culture system. Blood samples were taken from five healthy volunteers and four depressive patients. The release of interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) was measured quantitatively after an incubation time of 24 hours on microtiter plates. A massive suppression of the interleukin-6 release was found for PHA-stimulated hypericum extract. Possible relations to the antidepressive effects of hypericum extract are discussed.

Multicenter double-blind study examining the antidepressant effectiveness of the hypericum extract LI 160

Seventy-two depressive patients of 11 physicians' practices were treated in a double-blind study for a period of 6 weeks either with hypericum extract LI 160 or with placebo. Inclusion criterion was a major depression in accordance with DSM-III-R. The changes were assessed using four psychometric scales (HAMD, D-S, BEB, CGI). After 4 weeks of therapy, the statistical evaluation revealed a significant improvement in all four psychometric tests in the active group as compared to the placebo group. After switching the placebo group to active treatment (5th to 6th week of therapy), significant improvements were found in the original placebo group. No serious side effects were observed.

Pharmacokinetics of hypericin and pseudohypericin after oral intake of the hypericum perforatum extract LI 160 in healthy volunteers

The single- and multiple-dose pharmacokinetics of the naphthodianthrones hypericin and pseudohypericin derived from St. John's wort (Hypericum perforatum, LI 160, Lichtwer Pharma GmbH, Berlin) were studied in 12 healthy male subjects. After a single oral dose of 300, 900, or 1800 mg of dried hypericum extract (250, 750, or 1500 micrograms hypericin and 526, 1578, or 3156 micrograms pseudohypericin), plasma levels were measured with a modified highly sensitive high-pressure liquid chromatography (HPLC) method (lower detection limit 0.1 ng/mL) up to 3 days. The median maximal plasma levels were 1.5, 4.1, and 14.2 ng/mL for hypericin and 2.7, 11.7, and 30.6 ng/mL for pseudohypericin, respectively, for the three doses given above (interim evaluation of four volunteers). The median elimination half-life times of hypericin were 24.8 to 26.5 hours, and varied for pseudohypericin from 16.3 to 36.0 hours. Ranging between 2.0 to 2.6 hours, the median lag-time of absorption was remarkably prolonged for hypericin when compared to pseudohypericin (0.3 to 1.1 hours). The areas under the curves (AUC) showed a nonlinear increase with raising dose; this effect was statistically significant for hypericin. During long-term dosing (3 x 300 mg/day), a steady-state was reached after 4 days. Mean maximal plasma level during the steady-state treatment was 8.5 ng/mL for hypericin and 5.8 ng/mL for pseudohypericin, while mean trough levels were 5.3 ng/mL for hypericin and 3.7 ng/mL for pseudohypericin. In spite of their structural similarities there are substantial pharmacokinetic differences between hypericin and pseudohypericin.

Endotheliitis in hepatic allografts

Endotheliitis (EN) is a feature of hepatic allograft rejection, characterized by the adherence of immunocytes to the endothelium of veins, often leading to endothelial damage, endophlebitis, and, sometimes, panphlebitis. We found EN at least once in 28 of 41 allografts (68%) that had survived 6 months or longer. In approximately half the affected cases, the condition recurred. The EN was mild in most instances; moderate or severe manifestations were found in only 13% of the cases. The histologic changes were present for about 1 week in approximately half the cases; a duration of more than 2 weeks was noted in 17%, and then EN usually persisted. After retransplantation, recurrence of EN was observed in all of nine cases. We were unable to establish specific clinicopathologic and laboratory correlations for EN. The immunocytes in EN consisted mainly of helper and suppressor/cytotoxic T cells as well as natural killer cells. Sometimes, the immunocytes assumed a blastlike appearance; in these instances, the condition was severe. Such blastlike changes may be specific for EN. The immunocytes were attached to the endothelium by pseudopodia, broad bases, or both; some also were interconnected by cytoplasmic bridges. Underlying endothelial cells often showed evidence of cytoplasmic damage. The pathogenesis of EN is not completely understood; the immunocytes probably attach themselves to antigenic epitopes. Their nature, however, has not been clearly identified; HLA-A, B, and C and HLA-DR were displayed in areas of EN, but the antigens also were found in vessels without EN.