[Herbal medicines alternative to synthetical medicines]. / Phytopharmaka als Alternative zu Synthetika.

Herbal pharmaceuticals in medical practice are similarly used as chemically well defined drugs. Like other synthetical drugs, they are subject to pharmaceutical legislature (AMG) and EU directives. It is to differentiate between phytopharmaceuticals with effectiveness of proven indications and traditional registered herbal medicine. Through the Health Reform Act January 2004 and the policy of the Common Federal Committee (G-BA)on the contractual medical care from March 2009--with four exceptions--Non-prescription Phytopharmaka of the legal Health insurance is no longer (SHI) refundable and must be paid by the patients. The result is that more and more well-established preparations disappear from the market. This article gives an overview of practical relevant indications for herbal medicines, which according to its licensing status, the scientific assessment by the Cochrane Collaboration and the Institute for Quality and Efficiency in Health Care (IQWiG) and evidence-based Medicine (EBM)/ meta-analyzes as an alternative to synthetics can be used.

Downregulation of iNOS expression in rat mesangial cells by special extracts of Harpagophytum procumbens derives from harpagoside-dependent and independent effects.

Special extracts from the roots of Harpagophytum procumbens (Devil's Claw) are used in the supportive treatment of inflammatory diseases, and the iridoid derivative harpagoside is thought to be the active principle. To investigate, whether Harpagophytum extracts may also be useful therapeutics in the treatment of inflammatory kidney diseases, we studied the effects of two different extracts containing 8.9% (extract 1) and 27% harpagoside (extract 2), respectively, on IL-1beta-induced nitric oxide (NO) formation as well as transcriptional regulation of inducible NO synthase (iNOS) in rat renal mesangial cells. We observed a concentration-dependent suppression of nitrite formation by about 80%, which was due to an inhibition of iNOS expression. Moreover, a reduction of iNOS promoter activity and nuclear NF-kappaB translocation was observed, indicating that the extracts interfere with the transcriptional activation of iNOS. Three further Harpagophytum extracts containing about 2% harpagoside did not inhibit NO formation suggesting, that only extracts with a high harpagoside content elicit iNOS inhibition. However, pure harpagoside was only inhibitory at concentrations between 0.3 and 1 mg/ml, which is much higher than the harpagoside content present in an effective concentration of the total extracts. Moreover, a harpagoside-free extract 1 also markedly inhibited iNOS expression, indicating that other extract constituents are involved in this effect. Extract 1 exerted a strong antioxidative effect, whereas no such effect could be demonstrated for harpagoside. Together, these data show that special Harpagophytum extracts may represent potential antiinflammatory drugs in the treatment of glomerular inflammatory diseases.

Quality aspects of traditional and industrial Kava-extracts.

An aqueous decoction of Piper methysticum has been used since centuries of Pacific Island at social religious-ceremonial and social events without hepatotoxic side effects in contrast to the speculation on industrial Kava preparations. It was assumed that the traditional non-alcoholic drink contains a spectrum of other constituents compared to the acetonic and ethanolic extracts. The TLC-analysis demonstrates, however, that under qualitative aspects there is no difference between aqueous and acetonic and ethanolic extracts respectively.

Kava extracts: safety and risks including rare hepatotoxicity.

Kava is a perennial shrub native to some islands of the South Pacific and has been cultivated for centuries to prepare a psychoactive beverage from its rhizoma by means of extraction. Subsequently, kava extracts are commonly used as herbal anxiolytic drugs also in many other countries all over the world including European ones and the USA. Toxicological and clinical studies have shown that kava extracts are virtually devoid of toxic effects with the exception of rare hepatotoxic side effects reported in few patients. When assessed primarily by the British regulatory authority MCA but also by us, a critical analysis of the suspected cases (n = 19) in Germany reveals that only in 1 single patient a very probable causal relationship could be established between kava treatment and the development of toxic liver disease due to a positive result of an unscheduled reexposure test, whereas in another patient there might be a possible association. Out of the remaining 17 cases 12 patients were not yet assessable due to insufficient data and in 5 other cases a causal relationship was unlikely or could be excluded. The German regulatory authority might therefore well be advised to provide now additional information for those 12 patients with so far unsatisfactory data, facilitating a more appropriate assessment of causality. Nevertheless, in the meantime physicians and patients should continue to keep an eye on possible hepatotoxic side effects in the course of kava treatment, to stop the treatment alredy at first suspicion and to start with a careful diagnostic work up ruling out all other causes.

Differential therapy of constipation--a review.

Constipation is a common condition occurring with increasing frequency in advanced age. As a symptom, it is not always dealt with directly by the physician, but is often left to the care of nurses. Many patients rely on self-medication. Constipation not only interferes with the quality of life, but often has the rank of a syndrome requiring competent medical intervention. This is of clinical importance, because a thorough understanding of the pathophysiology of constipation enables the clinician to identify the potential causes and, if necessary, initiate a differentiated therapy with the aid of only simple additional investigations. This review outlines a clinical approach including medical history, spectrum of causes, radiopaque pellets method to differentiate between slow transit constipation and defecation disturbances for the differential diagnosis of constipation. The mechanisms of action of laxatives (anti-absorptive, secretagogue, osmotic, filling and swelling agents) are further components and important for the individual therapy. Based on this fundamental information, a differentiated therapy is possible in each specific case such as coprostasis. Chronic symptomatic constipation reduces the quality of life and should be evaluated by physicians. If situations such as drug-induced constipation or hypothyroidism which have to be treated causally can be ruled out, laxative treatment according to the clinical picture, mode of action of drug used and side effects of the laxative can be initiated. Laxative abuse due to chronic constipation is rare and almost always associated with psychosomatic-psychiatric disorders.

Camphor-Crataegus berry extract combination dose-dependently reduces tilt induced fall in blood pressure in orthostatic hypotension.

In order to test the efficacy of a combination of natural D-camphor and an extract of fresh crataegus berries (Korodin Herz-Kreislauf-Tropfen) on orthostatic hypotension, two similar, controlled, randomized studies were carried out in a balanced crossover design in 24 patients each with orthostatic dysregulation. The camphor-crataegus berry combination (CCC) was orally administered as a single regimen in 3 different dosages of 5 drops, 20 drops and 80 drops; a placebo with 20 drops of a 60% alcoholic solution served as control. Orthostatic hypotension was assessed with the tilt table test before and after medication. Source data of both studies were pooled and meta-analytically evaluated for all 48 patients. CCC drops decreased the orthostatic fall in blood pressure versus placebo, as almost uniformly established at all times by mean arterial pressure and diastolic blood pressure. Mean arterial pressure demonstrated the very fast onset of action by a clearly dose-dependent statistically significant effect even after 1-minute orthostasis. Increase of mean arterial pressure as compared to the orthostasis test before medication was on average 4.5 mmHg. CCC affected diastolic blood pressure after 1 minute of orthostasis in all dosages as compared to placebo. A statistically significant effect of the highest dose of 80 drops on diastolic blood pressure could be demonstrated after 1-, 3-, and 5-minute orthostasis. The hemodynamic findings of a stabilizing effect on arterial pressure in orthostasis corroborate the long-term medical experience with CCC and justify the indication orthostatic hypotension.

Approaching the problem of bioequivalence of herbal medicinal products.

Herbal medicinal products (HMP) contain exclusively herbal drugs or herbal drug preparations (HDP) and are a complex mixture of different compounds, which may act in an agonistic, synergistic, complementary, antagonistic or toxic way. A specific scientific challenge is for methods to prone the bioequivalence of herbal drug preparations (HDP). Depending on the type of herbal drug preparations, different approaches are possible. If the constituents responsible for therapeutic activity are known, the concept of essential similarity used with chemically defined substances can be fully applied. For extracts with unknown active markers, data on defined chemical constituents are useful for control purposes (charge conformity), but not sufficient to prove bioequivalence. In this case bioassays or pharmacological studies, which measure therapeutically relevant activity, should be used. A phytogeneric is only comparable to the innovator preparation under the following conditions: (i) pharmaceutical equivalence (standardization), (ii) biopharmaceutical equivalence (in vitro dissolution), (iii) bioequivalence with different endpoints (in vitro model, animal model) or (iv) clinical study. An uncritical substitution of herbal drug preparations without considering these scientific criteria should be avoided.

[Value of Ginkgo biloba in treatment of Alzheimer dementia]. / Stellenwert von Ginkgo biloba in der Behandlung der Alzheimer-Demenz.

During the last decade, there has been an explosive growth of research concerning the extract of Ginkgo biloba termed Egb 761. In experimental studies, animal studies and clinical studies Ginkgo biloba has shown a similar pharmacological potency and clinical efficacy like synthetic defined drugs in the therapy of reduced cerebral performance. Ginkgo biloba special extract Egb 761 is a standardized and highly purified extract of Ginkgo leaves. Among the active constituents are the ginkgo-flavone glycosides and the terpene-lactones (ginkgolides, bilobalide). The multifactorial principle of action of Ginkgo biloba is characterized by rheological and blood-flow-promoting properties, protective effects against ischaemia and hypoxia, effects on nerve cell energy metabolism, antioedematous and myelin-protective effects, radical-scavenger activity, effects on various cerebral transmitter and receptor systems. These action principles constitute the rationale for clinical trials in vascular dementia and primary degenerative dementia of the Alzheimer type, and in mixed forms of both. The cerebral bioavailability of Ginkgo biloba extract has been demonstrated by electroencephalography. In clinical trials of different working-groups, effects of Ginkgo biloba on the cognitive performance, global function, and activities of the daily living have been found. Metaanalysis in the indication--demential disorders--comparing Ginkgo biloba versus acetylcholinesterase inhibitors have shown a similar clinical efficacy of both therapy regimens with an additional drug safety benefit for Ginkgo. Due to the clinical efficacy the WHO accepted Ginkgo biloba as an antidementiv drug and add it in January 2000 into the recent ATC-Classification Index. In future antidementive therapy drugs with an different mode of action should be given in combination. Furthermore clinical trials with fixed combinations of acetylcholinesterase inhibitors with Ginkgo biloba extracts in moderate or severe dementia would be necessary.

Investigations on the pharmacokinetic properties of Harpagophytum extracts and their effects on eicosanoid biosynthesis in vitro and ex vivo.

PURPOSE: Harpagophytum extract and its marker substance harpagoside were shown to exert anti- inflammatory effects by interacting with the eicosanoid biosynthesis. In this study, different Harphagophytum extracts were tested with respect to inhibition of leukotriene and thromboxane biosynthesis in vitro and ex vivo. In addition, pharmacokinetic parameters of Harpagophytum extracts were investigated in vivo. METHODS AND SUBJECTS: Different fractions of Harpagophytum extracts were tested in vitro in human whole blood samples for effects on basal and ionophore A23187-stimulated cysteinyl-leukotriene (Cys-LT) and thromboxane synthesis. Furthermore, in 3 independent studies with different numbers of human male volunteers, a Harpagophytum extract was administered orally and tested in whole blood samples for Cys-LT and thromboxane B2 (TXB2) biosynthesis and for the determination of pharmacokinetic parameters of harpagoside. RESULTS: The special Harpagophytum extract WS1531 had a stronger inhibitory effect on ionophore A23187-stimulated Cys-LT levels compared with pure harpagoside or other extract fractions. Fractions without harpagoside had no pronounced inhibitory effect. When Cys-LT levels were measured after oral intake of Harpagophytum extract, a biphasic but dose-independent decrease of 28% and 58%, respectively, in basal Cys-LT formation was observed. Pharmacokinetic studies with the Harpagophytum extract WS1531 showed that the maximum levels of plasma harpagoside were reached after 1.3 to 2.5 hours. A linear relationship between dose and the first maximal concentration (Cmax) or area under the curve (AUC) (0-1)/AUC(0-infinity) was observed. CONCLUSIONS: Our observations strongly indicate a close relation between serum harpagoside levels and the inhibition of leukotriene biosynthesis.

Measurement of the bioavailability of aescin-containing extracts.

OBJECTIVE: In horse chestnut seed extracts (HCSE), the triterpene saponin mixture aescin is considered the active principle. The bioavailability and pharmacokinetics of different HCSE preparations have been studied under single and repeated applications using a radioimmunological method (RIA) developed to identify beta-aescin, one of the pharmacologically active fractions of the saponin mixture. In this paper, the available pharmacokinetic data are reviewed and the observed heterogenicity between comparable studies is discussed. DATA SOURCES: Pharmacokinetic data from 5 single- and 4 multiple-dose bioequivalence studies with HCSE-containing products, were measured by the same analytical laboratory using the same RIA. EVALUATION: In studies where procedures were identical the pharmacokinetic data of beta-aescin show high variations. Even under steady-state conditions a considerable variability for the same HCSE product is obtained. CONCLUSION: Formal reasons like study design and medications can be ruled out as a source of pharmacokinetic variation. In extracts of herbal drugs like HCS, the relative concentration of the individual saponin fractions can considerably differ from batch to batch. For immunological methods, identification of such antigens with intermolecular variability, e.g., the structural aescin analogs, is of unknown validity. Therefore the shape of the concentration-time curve would only show an approximation of the time course but not for the absolute concentrations. A specific validation procedure for the RIA must be developed, otherwise a LC-MS/MS-method of sufficient sensitivity should be elaborated.

[Phytogenic drugs in heart diseases exemplified by Crataegus]. / Phytopharmaka bei Herzerkrankungen am Beispiel von Crataegus.

According to the results, standardized extracts differ from other inotropic drugs used for treatment of chronic heart insufficiency. Crataegus extracts have positive inotropic, positive chronotropic, positive dromotropic but negative bathmotropic effects, increase coronary and myocardial perfusion, lower periphere resistance and has anti-arrhythmic and economizing effects. In randomized double-blind clinical trials, key surrogates for efficacy in chronic heart insufficiency were improved. Standardized Crataegus-extracts represent an alternative to synthetic drugs in patients with NYHA II in chronic heart insufficiency.

Studies on vitamin B12 status in the elderly--prophylactic and therapeutic consequences.

Because of the large liver stores (about 5 mg), low turnover rate (0.143%) and small daily requirement (3 micrograms), vitamin B12 deficiency does not occur under normal circumstances. This is not the case in individuals with chronic inflammatory or trophic changes at vitamin B12 absorption sites. Without supplementation, vitamin B12 deficiency can be expected within 5 years of gastrectomy. Characteristic features of type A gastritis are hyposecretion and mucosal atrophy in the fundus and body of the stomach, with absent intrinsic factor. In the small intestine, active and/or passive absorption is impaired by extensive ileal resection, exocrine pancreatic insufficiency and chronic inflammatory disorders such as Crohn's disease. Definitive plasma concentrations cannot be quoted for vitamin B12 deficiency. Dietary habits, subjective symptoms, hematological laboratory results, function tests and gastrointestinal endoscopic and histological findings must all be taken into account in the diagnosis. Modern diagnostic parameters, such as methylmalonic acid and homocysteine serum assays, are useful for achieving early diagnosis and hence optimal treatment. With their assured availability, parenteral vitamin B12 preparations remain the treatment of choice. Results from vitamin B12 bioavailability studies in healthy subjects suggest that > 300 micrograms probably suffices as an oral maintenance dose after parenteral loading. Further well-documented cases are needed in order to establish whether these doses are adequate in malabsorption syndromes and gastrointestinal diseases. Various case reports indicate the value of prophylactic and therapeutic oral vitamin B12 administration, especially in disorders of homocysteine metabolism, a substance postulated as a further important risk factor for atherosclerosis.

[The validity of radioimmunologic determination of bioavailability of beta-escin in horse chestnut extracts]. / Zur Validität radioimmunologisch bestimmter Bioverfügbarkeitsdaten von beta-Aescin in Rosskastaniensamenextrakten.

The bioavailability under steady state conditions of a standard, slow-release horse chestnut seed extract (HCSE)-containing product was compared with that of an analogous, fast-release test preparation (Noricaven novo) in a prospective, randomised, double-blind study in a double cross-over design. The serum concentration of beta-escin (CAS 6805-41-0) was measured by radioimmunoassay. In addition, the biopharmaceutical properties of the HCSEs present in the products were investigated, the amount and composition of the active ingredient, escin, being analysed with a validated HPLC method. The pharmacokinetics of this study were compared with the corresponding data of a similar investigation carried out under analogous conditions concerning study design, analytical methods and reference preparation. Comparison of the similar studies revealed differences in characteristic pharmakokinetic values of beta-escin in terms of a shift of the concentration time curves as could be demonstrated for the reference product. The total amounts of escin in the two products investigated did not differ significantly. However, quantitative and qualitative differences were detected in the constituents of the two different extract preparations. It is concluded that the high specificity of the validated beta-escin radioimmunoassay leads to analytical imprecision due to the variable constituents of the extract preparations used. It is necessary to test whether this problem can be solved using an analytical approach, which is specific for each extract.

[Planning, realization and evaluation of post-marketing surveillance studies. Recommendations of the Society for Phytotherapy]. / Planung, Durchführung und Auswertung von Anwendungsbeobachtungen. Empfehlungen der Gesellschaft für Phytotherapie (GPHY).

Post-marketing-surveillance studies with herbal drugs usually are prospective prescription-epidemiological studies, which should allow statements on quality, efficacy and safety. Until now neither laws nor concrete normative guidelines for the methodology and the evaluation of post-marketing-surveillance studies are existing which could be used for pharmacovigilance. In the present paper guidelines for planning, realisation and evaluation are presented which should allow studies of high quality. The essential components required for the investigational plan are focussed. Also recommendations on the obligatory, optional and special components of the study protocols are made. Additionally statistical methods which allow the evaluation of the therapeutic efficacy are presented.

Is the biopharmaceutical quality of extracts adequate for clinical pharmacology?

According to definition, an extract is a multi-substance mixture from a medicinal plant obtained by extraction of specific parts of the plant. Corresponding to the active ingredients in each case, each extract exhibits, qualitatively and quantitatively, a specific content spectrum, so that an extract is not just any extract. With an increasing demand for demonstrating the clinical efficacy of plant-based substances, extracts or extract fractions, we necessarily confront the problem of phytogenerics, i.e. extract-identical preparations for exchange versus the innovator. Up to now, pharmacognosic experts, phytochemists, and pharmacists have dealt with the problem as to the bioequivalence of phytopharmaceuticals within the context of pharmaceutical and biopharmaceutical/technological equivalence. In the meantime, however, from a number of plant extracts, the active ingredients determining their efficacy are known and analytical methods have been established, so that bioavailability/bioequivalence studies similar to those for chemical/synthetic substances are now possible.

Phytotherapy in heart failure.

According to the results of experimental investigations, standardized Crataegus extracts differ markedly from other inotropic drugs used for the treatment of heart failure. Crataegus has positive inotropic, positive chronotropic, positive dromotropic but negative bathmotropic effects, increases coronary and myocardial perfusion, lowers peripheral resistance and has antiarrhythmic and economising action with respect to oxygen and energy consumption. In randomised double-blind clinical trials, key surrogates required for demonstration of efficacy in heart failure were improved. Defined Crataegus extracts accordingly represent an alternative to synthetic drugs in patients with NYHA Grade II heart failure.

Pharmacokinetics of thiamine derivatives especially of benfotiamine.

Pharmacokinetic data of orally administered lipid-soluble thiamine analogues like benfotiamine are reviewed and assessed. It is quite clear that benfotiamine is absorbed much more better than water-soluble thiamine salts: maximum plasma levels of thiamine are about 5 times higher after benfotiamine, the bioavailability is at maximum about 3.6 times as high as that of thiamine hydrochloride and better than other lipophilic thiamine derivates. The physiological activity (alphaETK) increased only after benfotiamine was given. Due to its excellent pharmacokinetic profile benfotiamine should be preferred in treatment of relevant indications.

The effects of a special Agnus castus extract (BP1095E1) on prolactin secretion in healthy male subjects.

The effects of three doses of a special Agnus castus extract (BP1095E1)--extracts from 120 mg, 240 mg and 480 mg of drug per day--were examined within the framework of a placebo-controlled clinical study of tolerance and prolactin secretion in 20 healthy male subjects during a period of 14 days. There was good tolerance during the study as regards the following: adverse effects, the effects on blood pressure and heart rate, blood count, Quick's test, clinical chemistry as well as testosterone, FSH and LH values. During each study phase the 24-hour prolactin secretion profile was measured from the penultimate to the final day, and the amount of prolactin release was monitored an hour after TRH stimulation on the last day. A significant increase in the 24-hour profile was registered with the lowest dose in comparison to placebo, the opposite being the case with the higher doses, i.e. a slight reduction. In contrast to the administration of placebo, the 1-hour AUC after TRH stimulation resulted in a significant increase with the lowest dose and a significant reduction with the highest dose. The results suggest effects of the special Agnus castus extract which are dependent on the dose administered and the initial level of prolactin concentration.

Comparison of the effects of muzolimine and furosemide in patients with end-stage renal failure on chronic dialysis.

The pharmacodynamic effects of muzolimine and furosemide were compared in a single dose cross-over study in 8 patients on regular dialysis treatment, who had a residual diuresis of more than 300 ml/day. The study periods comprised two dialysis-free intervals of 3 days. On the second dialysis-free day either muzolimine 240 mg or furosemide 240 mg was administered orally. Urine was collected in 12-h periods on the pre-treatment, treatment and post-treatment days, and the excretion of sodium, potassium, urea and creatinine were measured. After administration of muzolimine 240 mg urine volume rose to twice that of the previous day, and sodium excretion increased approximately threefold. In contrast, the effect of furosemide 240 mg was not a pronounced; the diuresis was only 1.6 times that on the previous day and natriuresis was only 2.2 times as large. Excretion of potassium and creatinine was only slightly increased by either substance. The elimination of urea was increased by both substances to the same degree as the corresponding increase in diuresis.