Recent advances and new concepts for the synthesis of axially stereoenriched biaryls

Over the past decade the field of the synthesis of axially chiral compounds has been rapidly expanding. Not only key advances have been achieved concerning the already established strategies but also new synthetic routes have been devised. This review showcases the recent developments in this domain.

Management of pancreatic neuroendocrine tumors

Neuroendocrine tumors are a heterogeneous group of rare tumors originating from neuroendocrine cells with secretory characteristics, and are primarily located in gastric, duodenal, pancreatic, and small and large bowel mucosa. Due to their extremely variable biologic and clinical behaviour, diagnosis is often delayed after a prolonged workup. Many advances have been made in recent years in the diagnosis, characterization, and treatment of neuroendocrine tumors. This review focuses on pancreatic neuroendocrine tumors, discussing the relatively new, multidisciplinary approach to their management. A Pubmed search was performed, limited to papers published within the last five years, using the key words NETs, pancreatic NETs, pancreatic tumors, diagnosis, imaging, nuclear imaging, endoscopy, endoscopic ultrasound, and biochemical markers.

Clinical trial of Rhodiola rosea L. extract SHR-5 in the treatment of mild to moderate depression

The objective of this study was to assess the efficacy and safety of standardized extract SHR-5 of rhizomes of Rhodiola rosea L. in patients suffering from a current episode of mild/moderate depression. The phase III clinical trial was carried out as a randomized double-blind placebo-controlled study with parallel groups over 6 weeks. Participants, males and females aged 18-70 years, were selected according to DSM-IV diagnostic criteria for depression, the severity of which was determined by scores gained in Beck Depression Inventory and Hamilton Rating Scale for Depression (HAMD) questionnaires. Patients with initial HAMD scores between 21 and 31 were randomized into three groups, one of which (group A: 31 patients) received two tablets daily of SHR-5 (340 mg/day), a second (group B: 29 patients) received two tablets twice per day of SHR-5 (680 mg/day), and a third (group C: 29 patients) received two placebo tablets daily. The efficacy of SHR-5 extract with respect to depressive complaints was assessed on days 0 and 42 of the study period from total and specific subgroup HAMD scores. For individuals in groups A and B, overall depression, together with insomnia, emotional instability and somatization, but not self-esteem, improved significantly following medication, whilst the placebo group did not show such improvements. No serious side-effects were reported in any of the groups A-C. It is concluded that the standardized extract SHR-5 shows anti-depressive potency in patients with mild to moderate depression when administered in dosages of either 340 or 680 mg/day over a 6-week period.

Stimulating effect of adaptogens: an overview with particular reference to their efficacy following single dose administration

Plant adaptogens are compounds that increase the ability of an organism to adapt to environmental factors and to avoid damage from such factors. The beneficial effects of multi-dose administration of adaptogens are mainly associated with the hypothalamic-pituitary-adrenal (HPA) axis, a part of the stress-system that is believed to play a primary role in the reactions of the body to repeated stress and adaptation. In contrast, the single dose application of adaptogens is important in situations that require a rapid response to tension or to a stressful situation. In this case, the effects of the adaptogens are associated with another part of the stress-system, namely, the sympatho-adrenal-system (SAS), that provides a rapid response mechanism mainly to control the acute reaction of the organism to a stressor. This review focuses primarily on the SAS-mediated stimulating effects of single doses of adaptogens derived from Rhodiola rosea, Schizandra chinensis and Eleutherococcus senticosus. The use of these drugs typically generates no side effects, unlike traditional stimulants that possess addiction, tolerance and abuse potential, produce a negative effect on sleep structure, and cause rebound hypersomnolence or 'come down' effects. Furthermore, single administration of these adaptogens effectively increases mental performance and physical working capacity in humans. R. rosea is the most active of the three plant adaptogens producing, within 30 min of administration, a stimulating effect that continues for at least 4-6 h. The active principles of the three plants that exhibit single dose stimulating effects are glycosides of phenylpropane- and phenylethane-based phenolic compounds such as salidroside, rosavin, syringin and triandrin, the latter being the most active.

Impact of Chisan (ADAPT-232) on the quality-of-life and its efficacy as an adjuvant in the treatment of acute non-specific pneumonia

A double-blind, placebo-controlled, randomized (simple randomisation), pilot (phase III) study of Chisan, (ADAPT-232; a standardised fixed combination of extracts of Rhodiola rosea L., Schisandra chinensis Turcz. Baill., and Eleutherococcus senticosus Maxim) was carried out on two parallel groups of patients suffering from acute nonspecific pneumonia. Sixty patients (males and females; 18-65 years old) received a standard treatment with cephazoline, bromhexine, and theophylline: in addition, one group of 30 patients was given Chisan mixture, whilst the second group of 30 patients received a placebo, each medication being taken twice daily from the beginning of the study for 10-15 days. The primary outcome measurements were the duration of antibiotic therapy associated with the clinical manifestations of the acute phase of the disease, together with an evaluation of mental performance in a psychometric test and the self-evaluation of quality-of-life (QOL) (WHOQOL-Bref questionnaires) before treatment and on the first and fifth days after clinical convalescence. The mean duration of treatment with antibiotics required to bring about recovery from the acute phase of the disease was 2 days shorter in patients treated with Chisan compared with those in the placebo group. With respect to all QOL domains (physical, psychological, social and ecological), patients in the Chisan group scored higher at the beginning of the rehabilitation period, and significantly higher on the fifth day after clinical convalescence, than patients in the control group. Clearly, adjuvant therapy with ADAPT-232 has a positive effect on the recovery of patients by decreasing the duration of the acute phase of the illness, by increasing mental performance of patients in the rehabilitation period, and by improving their QOL. Both the clinical and laboratory results of the present study suggest that Chisan (ADAPT-232) can be recommended in the standard treatment of patients with acute non-specific pneumonia as an adjuvant to increase the QOL and to expedite the recovery of patients.

Randomized trial of a fixed combination (KanJang) of herbal extracts containing Adhatoda vasica, Echinacea purpurea and Eleutherococcus senticosus in patients with upper respiratory tract infections

The clinical efficacy of KanJang oral solution, a fixed combination of standardised extracts of Echinacea purpurea, Adhatoda vasica and Eleutherococcus senticosus, was compared with the combined extracts of Echinacea purpurea and Eleutherococcus senticosus alone (Echinacea mixture) in a controlled, double blind, randomized trial, and with Bromhexine (a standard treatment) in a controlled, open, randomized clinical trial on patients with non-complicated acute respiratory tract infections. Many of the parameters evaluated, such as severity of coughing, frequency of coughing, efficacy of mucus discharge in the respiratory tract, nasal congestion and a general feeling of sickness, showed significantly greater improvement in patients treated with KanJang compared with those receiving the standard treatment. However, no significant differences in the improvement of these symptoms (except in a reduced frequency of coughing) were observed between patients treated with the Echinacea mixture and those receiving the standard treatment. The only explanation is that the lack of extract of A. vasica in the Echinacea mixture reduces its efficacy compared with the complete KanJang oral solution even though direct double-blind comparison yielded no significant differences between these two groups of patients. The recovery time of patients being treated with KanJang or Echinacea mixture was 2 days shorter than that of patients receiving the standard treatment. None of the patients completing the study reported adverse reactions to the medication taken. The significance of the results obtained in this study is discussed with respect to the efficacy of KanJang in the treatment of acute respiratory infection and to the concept that multi-drug therapy offers higher efficacy compared with mono-drug treatment of such infections.

A phase I clinical study of Andrographis paniculata fixed combination Kan Jang versus ginseng and valerian on the semen quality of healthy male subjects

The safety of different doses of Kan Jang--a fixed combination of Andrographis paniculata special extract (SHA-10) and Acanthopanax senticosus--compared to two extensively used medicinal plants, Valeriana officinalis and Panax ginseng in the form of standardized extracts, has been examined. A phase I clinical study was designed to evaluate the effect on semen quality of healthy males in terms of spermatogenesis and quality of semen. The results of the study revealed no significant negative effect of Kan Jang on male semen quality and fertility, but rather a positive trend with respect to the number of spermatozoids in the whole ejaculate, the percentage of active (normokinetic) forms of spermatozoids, and fertility indexes, together with a decrease in the percentage of inactive (diskinetic) forms of spermatozoids. In the group receiving ginseng, no significant negative effects on the fertility parameters were revealed and there was a clear decrease in the percentage of diskinetic forms of spermatozoids. Subjects receiving valerian showed a temporary increase in the percentage of normokinetic spermatozoids and a decrease in diskinetic forms, but these changes had no effect on fertility indices. The results indicate that Kan Jang, ginseng and valerian are safe with respect to effects on human male sterility when administered at dose levels corresponding to approximately 3 times the human daily dose.

Methods of phytochemical standardisation of rhizoma Cimicifugae racemosae

The methanolic extract of roots of Cimicifuga racemosa and its methanolysis products have been analysed by GC-MS. 2-Hexylcyclopropaneoctanoic acid (9,10-methylenehexadecanoic acid) was found to be the marker most specific for the identification for this herb. For the phytochemical standardisation of Rhizoma Cimicifugae racemosae, validated methods for the quantitative analysis of formononetin (by TLC-fluorometry), of isoferulic acid (by GC-MS of the methyl ester), and of total triterpene glycosides (transformed to coloured complexes and measured photometrically) in roots of C. racemosa have been developed. The contents of formononetin, isoferulic acid and total triterpene glycosides (measured as actein) in the herb ranged from 0.0031 to 0.0035, from 1.22 to 1.35 and from 20.09 to 22.06 mg/g dry weight, respectively.

Plasma nitric oxide level in familial Mediterranean fever and its modulations by Immuno-Guard

Familial Mediterranean fever (FMF) is a recessively inherited inflammatory disorder, characterised by recurrent attacks of fever and serositis. Since nitric oxide (NO) is an important mediator of inflammation, the production of NO (assessed as the accumulation of nitrate and nitrite and measured by capillary electrophoresis) in blood plasma of FMF patients during acute attacks (active) and attack-free periods (inactive) of the disease has been determined and compared with NO levels found in healthy volunteers (control group C). Thirty-six FMF patients were involved in a placebo-controlled double-blind study (group A received the drug, group B the placebo) of the effects of Immuno-Guard, a novel herbal preparation which relieves the severity and longevity of FMF attacks on NO blood levels. Thirty-two FMF patients (group D) being permanently treated with colchicine were also examined with respect to their NO blood level. No significant differences were found between the NO levels in blood of inactive FMF patients and those of control group C, or between inactive colchicine-treated group D patients and inactive patients of groups A and B, a finding which is atypical for chronic inflammatory disorders. Significantly lower plasma NO levels were found in active FMF patients in groups A and B compared with inactive patients in those groups (p=0.031 and 0.036, respectively) and with patients of group D and the control group C (p=0.0235 and 0.0453, respectively). The decrease of NO in blood of FMF patients may trigger the generation of fever by initiating the production of pro-inflammatory IL-6. Plasma NO levels in inactive FMF patients were significantly increased during attack-free periods following treatment with Immuno-Guard. The preparation has a normalising effect both on NO and IL-6 blood levels in FMF patients during attacks, demonstrating a relationship between the beneficial effect of Immuno-Guard in reducing the severity of inflammatory attacks in FMF patients and the increase in NO blood levels.

Double-blind, placebo-controlled, randomized, pilot clinical trial of ImmunoGuard--a standardized fixed combination of Andrographis paniculata Nees, with Eleutherococcus senticosus Maxim, Schizandra chinensis Bail. and Glycyrrhiza glabra L. extracts in patients with Familial Mediterranean Fever

Double blind, randomized, placebo controlled pilot study of ImmunoGuard--a standardized fixed combination of Andrographis paniculata Nees., Eleutherococcus senticosus Maxim., Schizandra chinensis Bail., and Glycyrrhiza glabra L. special extracts standardized for the content of Andrographolide (4 mg/tablet), Eleuteroside E, Schisandrins and Glycyrrhizin, was carried out in two parallel groups of patients. The study was conducted in 24 (3-15 years of both genders) patients with Familial Mediterranean Fever (FMF), 14 were treated with tablets of series A (verum) and 10 patients received series B product (placebo). The study medication was taken three times of four tablets daily for 1 month. Daily dose of the andrographolide--48 mg. The primary outcome measures in physician's evaluation were related to duration, frequency and severity of attacks in FMF patients (attacks characteristics score). The patient's self-evaluation was based mainly on symptoms--abdominal, chest pains, temperature, arthritis, myalgia, erysipelas-like erythema. All of 3 features (duration, frequency, severity of attacks) showed significant improvement in the verum group as compared with the placebo. In both clinical and self evaluation the severity of attacks was found to show the most significant improvement in the verum group. Both the clinical and laboratory results of the present phase II (pilot) clinical study suggest that ImmunoGuard is a safe and efficacious herbal drug for the management of patients with FMF.

Effect of andrographolide and Kan Jang--fixed combination of extract SHA-10 and extract SHE-3--on proliferation of human lymphocytes, production of cytokines and immune activation markers in the whole blood cells culture

The immunomodulatory properties of a diterpene lactone andrographolide and Kan Jang--a standardized fixed combination of Andrographis paniculata extract SHA-10 and Eleutherococcus senticosus extract SHE-3 were investigated. Their role on spontaneous and phytohemagglutinin (PHA)-induced proliferation of human peripheral blood lymphocytes (PBL) and on production of interferon-gamma (INF-gamma) and tumor necrosis factor-alpha (TNF-alpha) were determined in vitro. Proliferation of PBL induced by PHA was enhanced by co stimulation with andrographolide and Kan Jang. At the same time andrographolide and Kan Jang inhibit spontaneous proliferation of PBL in vitro. These preparations also have effect on the formation of INF-gamma, TNF-alpha and some immune activation markers such as neopterin (Neo), beta-2-microglobulin (beta2MG), and soluble receptor for interleukin-2 (sIL-2R or sCD25) in blood cells culture. Andrographolide and Kan Jang stimulate the INF-gamma, Neopterin and beta2MG formation, but do not have any significant effect on the production of INF-gamma and Neopterin in PHA stimulated blood cells. An opposite effect on these immune makers was observed in the PHA-stimulated blood cells: both andrographolide and Kan Jang increase the formation of TNF-alpha and beta2MG in cultivated whole blood cells. Thus, andrographolide and Kan Jang can have an in vitro effect on the activation and proliferation of immunocompetent cells as well on the production of key cytokines and immune activation markers. The results show an overall higher effect of the fixed combination as compared with the equivalent amount of the pure substance andrographolide. The data are consistent with results from clinical studies of Kan Jang and contributed to a better understanding of these results.

Analysis of aromatic aldehydes in brandy and wine by high-performance capillary electrophoresis

A new method of analysis of vanillin, syringaldehyde, coniferaldehyde, and sinapaldehyde in brandy and wine by high-performance capillary electrophoresis is described. Electrophoretic mobility of these compounds is achieved by a borate buffer at pH 9.3. At this pH, the sensitivity of UV detection of these phenolic aldehydes also increases. UV absorptions at 348, 362, 404, and 422 nm were selected for monitoring vanillin, syringaldehyde, coniferaldehyde, and sinapaldehyde, respectively. This procedure was performed simultaneously during one run using a diode array detector. Samples of brandy or wine were analyzed directly without concentration, extraction, or any other preliminary treatment of the test sample. The limits of detection were found to be 0.275, 0.1425, 0.1475, and 0.1975 ppm for syringaldehyde, coniferaldehyde, sinapaldehyde, and vanillin, respectively, which is acceptable for analysis of both brandy and wine aged in oak barrels. The method has been shown to be linear in a range from 0.3 to 57 mg/L. Recoveries ranged between 99.9% and 107.7% for all of the compounds tested. Repeatability and reproducibility of the method were high. The relative standard deviation was consequently approximately 3% and also between 4.47% and 6.89% for all tested compounds. The method is useful for the identification of counterfeit brandy, which is easy to recognize by the absence of sinapaldehyde, syringaldehyde, and coniferaldehyde, which are not detectable in false brandy.

Effects of cell concentration and growth period on articular and ear chondrocyte transplants for tissue engineering

This study determined the effects of chondrocyte source, cell concentration, and growth period on cartilage production when isolated porcine cells are injected subcutaneously in a nude mouse model. Chondrocytes were isolated from both ear and articular cartilage and were suspended in Ham's F-12 medium at concentrations of 10, 20, 40, and 80 million cells per cubic centimeter. Using the nude mouse model, each concentration group was injected subcutaneously in 100-microl aliquots and was allowed to incubate for 6 weeks in vivo. In addition, cells suspended at a fixed concentration of 40 million cells per cubic centimeter were injected in 100-microl aliquots and were incubated for 1, 2, 3, 4, 5, 6, 9, and 12 weeks. Each concentration or time period studied contained a total of eight mice, with four samples harvested per mouse for a final sample size of 32 constructs. All neocartilage samples were analyzed by histologic characteristics, mass, glycosaminoglycan level, and DNA content. Control groups consisted of native porcine ear and articular cartilage. Specimen mass increased with increasing concentration and incubation time. Ear neocartilage was larger than articular neocartilage at each concentration and time period. At 40 million cells per cubic centimeter, both ear and articular chondrocytes produced optimal neocartilage, without limitations in growth. Specimen mass increased with incubation time up to 6 weeks in both ear and articular samples. No significant variations in glycosaminoglycan content were found in either articular or ear neocartilage, with respect to variable chondrocyte concentration or growth period. Although articular samples demonstrated no significant trends in DNA content over time, ear specimens showed decreasing values through 6 weeks, inversely proportional to increase in specimen mass. Although both articular and ear sources of chondrocytes have been used in past tissue-engineering studies with success, this study indicates that a suspension of ear chondrocytes injected into a subcutaneous location will produce biochemical and histologic data with greater similarity to those of native cartilage. The authors believe that this phenomenon is attributable to the local environment in which isolated chondrocytes from different sources are introduced. The subcutaneous environment of native ear cartilage accommodates subcutaneously injected ear chondrocyte transplants better than articular transplants. Native structural and biochemical cues within the local environment are believed to guide the proliferation of the differentiated chondrocytes.

Rhodiola rosea in stress induced fatigue--a double blind cross-over study of a standardized extract SHR-5 with a repeated low-dose regimen on the mental performance of healthy physicians during night duty

The aim of this study was to investigate the effect of repeated low-dose treatment with a standardized extract SHR/5 of rhizome Rhodiola rosea L, (RRE) on fatigue during night duty among a group of 56 young, healthy physicians. The effect was measured as total mental performance calculated as Fatigue Index. The tests chosen reflect an overall level of mental fatigue, involving complex perceptive and cognitive cerebral functions, such as associative thinking, short-term memory, calculation and ability of concentration, and speed of audio-visual perception. These parameters were tested before and after night duty during three periods of two weeks each: a) a test period of one RRE/placebo tablet daily, b) a washout period and c) a third period of one placebo/RRE tablet daily, in a double-blind cross-over trial. The perceptive and cognitive cerebral functions mentioned above were investigated using 5 different tests. A statistically significant improvement in these tests was observed in the treatment group (RRE) during the first two weeks period. No side-effects were reported for either treatment noted. These results suggest that RRE can reduce general fatigue under certain stressful conditions.

Pharmacokinetic and oral bioavailability of andrographolide from Andrographis paniculata fixed combination Kan Jang in rats and human

Validated analytical methods (HPLC, CE and GC-MS) for determining the amount of andrographolide (AND) in the blood plasma of rats and human volunteers following the oral administration of Andrographis paniculata extract (APE) and Andrographis paniculata fixed combination Kan Jang tablets were developed and used for the pharmacokinetic study. Andrographolide was quickly and almost completely absorbed into the blood following the oral administration of APE at a dose of 20 mg/kg body wt. in rats. Its bio-availability, however, decreased four-fold when a 10-times-higher dose was used. Since a large part (55 %) of AND is bound to plasma proteins and only a limited amount can enter the cells, the pharmacokinetics of AND are described well by a one-compartment model. Renal excretion is not the main route for eliminating AND. It is most likely intensely and dose dependently metabolized. Following the oral administration of four Kan Jang tablets (a single therapeutic dose, equal to 20 mg of AND) to humans, maximum plasma levels of approximately 393 ng/ml (approx. 1.12 microM) were reached after 1.5-2 hours, as quantified using a UV diode-array detection method. Half-life and mean residence times were 6.6 and 10.0 hours, respectively. AND pharmacokinetics in humans are explained well by an open two-compartment model. The calculated steady state plasma concentration of AND for multiple doses of Kan Jang (after the normal therapeutic dose regimen, 3 x 4 tablets/day, about 1 mg AND/kg body wt./day) was approximately 660 ng/ml (approx. 1.9 microM), enough to reveal any anti-PAF effect, particularly after drug uptake when the concentration of AND in blood is about 1342 ng/ml (approx. 3.8 microM, while for anti-PAF effect EC50 - 5 microM).

Plant adaptogens. III. Earlier and more recent aspects and concepts on their mode of action

Stimulus-response coupling systems responsible for defence and adaptation of organism to stressors are multi-target and very complicated pharmacological systems, including the neuroendocrine (stress) and immune system. The mode of action of adaptogens is basically associated with the stress-system (neuroendocrine-immune complex) and can be directed on the various targets of the system involved in regulation (activation and inhibition) of stimulus-response coupling. However, clinical studies performed according to the most modern standards are quite limited. On the other hand there is an extensive amount of clinical experience and also established use in self care etc. These aspects are planned to be dealt within a subsequent article which will be devoted to the application in three areas: self care, adjuvants in medicine and curative action in some diseases. At this stage, nevertheless, it seems possible to define some most important "stress-markers" for evaluation of efficiency of adaptogens in experimental and clinical pharmacological studies. They can be both activating (catecholamines, LT-s, cytokines, NO, etc.--"switch on" system--which activates energetic and other resources of the organism), and deactivating (corticosteroids and PGE2-endogenous mediators of cellular communications, which protect cells and whole organism from overreacting to the activating messengers--"switch off" system) stress-messengers. The balance between the activities of the "switch on" and "switch off" systems reflects the well being of the organism. It could be established on different levels of the homeostasis (heterostasis) with different levels of the sensitivity to stressors (Figure 8). The response of stress system--"reactivity" is different at the various levels of heterostasis and depends on adaptation--capacity of the organism (or a cell) to protect itself. In the process of adaptation to stressor's effects the basal levels mediators of switch on (e.g. NO) and switch of (e.g. cortisol) systems are increasing but their balance (the ratio) does not change. In other words, adaptogens increase the capacity of stress system to respond to external signals at the higher level of the equilibrium of activating and deactivating mediators of stress response. Consequently, plant adaptogens can be defined as "smooth" pro-stressors which reduce reactivity of host defense systems and decrease damaging effects of various stressors due to increased basal level of mediators involved in the stress-response. In further studies of adaptogens it seems important to find correlation between adaptogenic activity (a decrease in the "reactivity" of the organism--the basal level of activating and deactivating messengers: ILs, LTB4, NO, PGE2, cortisol, but not their ratio) and their therapeutic efficiency (symptomatic evaluation).

Effect of Andrographis paniculata extract on progesterone in blood plasma of pregnant rats

The effect of the powdered extract of Andrographis paniculata leaves (APE), an active principle of Kan Jang tablets [standardized for content of andrographolide (4.6%) and 14-deoxo-andrographolide (2.3%) content (total andrographolids--6.9%)] on blood progesterone content in rats was studied. Peroral administration of APE during the first 19 days of pregnancy in doses of 200, 600, and 2000 mg/kg (i.e. doses 30, 90, and 300 fold higher than its daily therapeutic dose in humans) does not exhibit any effect on the elevated level of progesterone in the blood plasma of rats. Let us assume then that in therapeutic dose, Andrographis paniculata extract cannot induce progesterone-mediated termination of pregnancy.

On the mechanism of action of plant adaptogens with particular reference to cucurbitacin R diglucoside

Cucurbitacin R diglucoside (DCR), one of the active principles of Bryonia alba L. root was found to have an effect on the production of corticosteroids and the biosynthesis of eicosanoids in the adrenal cortex, isolated adrenocortical cells, blood plasma, and leukocytes under stress and stress-free conditions in vitro and vivo. DCR prevents stress-induced alterations of eicosanoids in blood and moderately stimulates the adrenal cortex to adapt organism to stress, because a moderate increase in corticosteroid secretion protects the defense system of organisms from becoming hyperactive. DCR enhances sensitivity to stress due to the effects of eicosanoids and corticosteroids.

Inhibitory effect of andrographolide from Andrographis paniculata on PAF-induced platelet aggregation

Andrographolide, an active principle of the Chinese drug Andrographis paniculata, used for prevention and treatment of common cold in Scandinavia and known as an antiinflammatory, antiviral, antithrombotic, hypotensive and antiatherosclerotic drug, was investigated for its suggested influence on the biosynthesis of eicosanoids and the platelet-activating factor (PAF). Whereas in isolated human polymorph-nuclear leukocytes (PMNL) no influence on the biosynthesis was found, it could be shown that andrographolide inhibits PAF-induced human blood platelet aggregation in a dose dependent manner (IC50-5 microM). These results indicate that andrographolide has a mechanism of action different from that of non-steroidal antiinflammatory drugs (NSAID) and most likely associated with the cardiovascular and antithrombotic activity described of Andrographis paniculata.

Pharmacological activity of phenylpropanoids of the mistletoe, Viscum album L., host: Pyrus caucasica Fed

Although a great number of compounds have been isolated from Viscum album (mistletoe, Viscaceae), none of them could be clearly shown to possess the established hypotensive, vasodilator, cardiotonic and antitumor activity of alcoholic preparations. In the course of our investigation of Armenian mistletoe Viscum album, host: Pyrus caucasica, which has been used in Armenian traditional medicine for the treatment of cardiovascular diseases and for stimulation of the immune system, four phenylpropanoid glycosides were isolated from EtOH-extract: coniferyl alcohol 4-O-β-D-glucopyranoside (coniferin), syringenin 4-O-β-D-glucopyranoside (syringin), and coniferylalcohol- and syringenin 4-O-β-D-apiofuranosyl (1→2)-β-D-glucopyranosides. The structures were established on the basis of the spectral and chemical data. All substances inhibited ADP-induced platelet aggregation, and the apiosyldiglycosides only inhibited leukotriene B4 release from TPA and calcium ionophore A-23187 stimulated human granulocytes. It is suggested that an antitumoral effect of ethanolic extract of Viscum album could be associated with the inhibition of protein kinase C (PKC).

Beditine, a new benzodioxane derivative, as a suppressor of human polymorphonuclear leukocyte and platelet activation

Beditine, 2-(2-amino-4-thiazolyl)-1,4-benzodioxane hydrochloride is a new substance which reduced platelet activation and degranulation, prevented aggregation and superoxide generation by activated human polymorphonuclear leukocytes (PMNL) and inhibited the activation of arachidonate 5-lipoxygenase. Beditine may, therefore, be a useful agent in the treatment of cardiovascular disease.

On the mechanism of biosynthesis of leukotrienes and related compounds

[10D-3H; 3-14C]- and [10L-3H; 3-14C]arachidonic acids were incubated with human polymorphonuclear leukocytes and with human platelets. Leukotriene B4 and 5(S),12(S)-dihydroxy-6trans,8cis,10trans,14-cis-eicosatetraenoic acid (5,12-DHETE) were isolated and the 3H/14C ratios determined. It could be concluded that the 10D (pro-R)-hydrogen is eliminated in the conversion of 5(S)-hydroperoxy-6trans,8-cis,11cis,14cis-eicosatetraenoic acid into leukotriene A4 whereas in the conversion of arachidonic acid into 5,12-DHETE the 10L (pro-S)-hydrogen is lost. Incubation of the doubly labeled arachidonic acids with human platelets confirmed and extended previous data on the stereochemistry of the hydrogen removal from C-10 during the conversion into 12(S)-hydroperoxy-5cis,8cis,10trans,14cis-eicosatetraenoic acid, i.e., the 10L (pro-S)-hydrogen is eliminated and the 10D (pro-R)-hydrogen retained.