Total steroidal alkaloids from Veratrum patulum L. Inhibit platelet aggregation, thrombi formation and decrease bleeding time in rats

Ethnopharmacological relevance

Veratrum patulum L. (Liliaceae) is used as one source of the Chinese traditional drug “Lilu” which has been used in the treatment of aphasia arising from apoplexy, wind type dysentery, headache, etc. for thousands of years.

Aim of the study

To evaluate the antithrombotic effect of Veratrum patulum L. (Liliaceae) total steroidal alkaloids (VpA) and explore the potential mechanisms.

Materials and methods

The antithrombotic effect of VpA was evaluated in two experimental thrombosis models in rat. The potential antithrombotic mechanisms of VpA were explored by determining the coagulation parameters and platelet aggregation induced by various agonists. Cutting-tail rat model was used to evaluate the influence of VpA on bleeding time.

Results

VpA significantly inhibit the formation of arterial and venous thrombosis and showed different inhibitory effect on the platelet aggregation induced by various agonists with the following potency order: collagen > ADP > thrombin. VpA showed no influence on the coagulation parameters in rat. But VpA decreased the cutting-tail bleeding time in rat.

Conclusion

VpA possess antithrombotic effect on venous and arterial thrombosis. The antithrombotic effect of VpA is due to its inhibition to platelet aggregation, especially induced by collagen.     

Antiplatelet and anticoagulant effects of Panax notoginseng: Comparison of raw and steamed Panax notoginseng with Panax ginseng and Panax quinquefolium

Ethnopharmacological significance

Panax notoginseng (Burk.) F. H. Chen (Araliacea) is traditionally used for its hemostatic and cardiovascular effects when raw and as a tonic when steamed.

Aim of the study

This study aims to compare the effects of raw and steamed Panax notoginseng, Panax ginseng C. A. Meyer and Panax quinquefolium Linn. on platelet aggregation and plasma coagulation.

Materials and methods

Effects on collagen-induced platelet aggregation were investigated using a platelet aggregometer, while the plasma coagulation times (prothrombin time, activated partial thromboplastin time and thrombin time) were determined using a blood coagulation analyzer. The data was corroborated with ex vivo platelet aggregation and in vivo rat bleeding time.

Results

Raw and steamed Panax notoginseng significantly inhibit platelet aggregation and plasma coagulation. Steamed Panax notoginseng has significantly more potent antiplatelet and anticoagulant effects than the raw extract, and the antiplatelet and anticoagulant effects increase with increasing steaming durations. Comparing the three common Panax species, Panax notoginseng has higher antiplatelet effect than Panax ginseng and Panax quinquefolium. The in vitro antiplatelet and anticoagulant effects are positively translated into a prolongation of in vivo rat bleeding time after oral administration of the raw and steamed extracts.

Conclusion

The results indicate that the three common Panax species affect platelet aggregation and plasma coagulation differently, with steamed Panax notoginseng showing the greatest antiplatelet and anticoagulant effects. Panax notoginseng may be a good source of lead compounds for novel antiplatelet and anticoagulant therapeutics.     

Hypercoagulability in cancer patients grouped by syndromes differentiated with the theory of abnormal hilit in traditional Uyghur medicine

Objective

To investigate the relationship in malignant-neoplasm patients of hypercoagulability between syndromes differentiated with the theory of abnormal hilit in traditional Uyghur medicine (TUM).

Methods

A total of 248 patients with malignant tumors were enrolled. Based on the theory of TUM they were divided into two groups: abnormal Savda and abnormal Non-Savda (including abnormal Khan, abnormal Sepra and abnormal Belghem types); fifty healthy volunteers were selected as controls. Platelet (PLT), prothrombin time (PT), plasma fibrinogen (FIB), thrombin time (TT), activated partial thromboplastin time (aPTT) and D-Dimer (D-D) were measured in both groups.

Results

Compared with the control and abnormal Non-Savda groups, in the abnormal Savda group the PLT count increased (P<0.05), the PT was lengthened (P<0.01), and the FIB significantly increased (P<0.01). D-Ds in the three groups were significantly different (P<0.05). No significant difference was found in TT and aPTT values (P>0.05).

Conclusion

Hypercoagulability existed in patients with malignant tumors in the different types of TUM syndromes, especially in the abnormal Savda group; this was characterized by increased blood viscosity, platelet aggregation and thrombosis. D-D appears to be a significant predictor for the therapeutic effect of TUM in relation to malignant tumor therapies.     

Purification and characterization of a novel antithrombotic peptide from Scolopendra subspinipes mutilans

Ethnopharmacological relevance

The centipede has been prescribed for the treatment of cardiovascular diseases in Korea, China and other Far Eastern Asian countries for several hundred years.

Materials and methods

A novel antithrombotic peptide was isolated from Scolopendra subspinipes mutilans using a combination of ultrafiltration, Sephadex G-50 column, Source 15Q anion exchange column and RP-HPLC C18 column.

Results

The molecular mass of the purified peptide is 346 Da measured by Electrospray Ionization Mass Spectrometry (ESI-MS). The primary structure of the peptide is Ser-Gln-Leu (SQL) determined by Edman degradation. SQL potently prolonged the activated partial thromboplastin time (aPTT), and inhibited platelet aggregation.

Conclusions

These results help to clarify the mechanism of the antithrombotic activity of the centipede for effective treatment of cardiovascular and cerebrovascular diseases.     

Pharmacokinetics of 8-O-acetylharpagide and harpagide after oral administration of Ajuga decumbens Thunb extract in rats

Ethnopharmacological relevance

Ajuga decumbens Thunb is a medicinal plant native to China popularly used to treat chronic pelvic inflammation and hysteromyoma. Its main bioactive components are iridoid glycosides, such as 8-O-acetylharpagide and harpagide that had presented antibacterial, anti-inflammatory, and antiviral activities.

Aim of the study

To establish a sensitive LC–MS/MS method and compare the pharmacokinetics of 8-O-acetylharpagide and harpagide in rats after oral administration of their pure forms and from compounds obtained from Ajuga decumbens extract.

Materials and methods

Rats received orally 15 mg/kg (equivalent of 6 mg/kg 8-O-acetylharpagide and 1.5 mg/kg harpagide), 30 mg/kg and 60 mg/kg of Ajuga decumbens Thunb extract and were compared to animals that received 12 mg/kg of 8-O-acetylharpagide or 3 mg/kg of harpagide p.o. Concentrations of 8-O-acetylharpagide and harpagide in plasma were determined by LC–MS/MS method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis.

Results

Results showed that the iridoid glycosides were quickly absorbed by oral route and showed a dose-dependence profile. Pharmacokinetic parameters of both glycosides were essentially the same except Tmax when dosed as the extract or pure forms.

Conclusion

8-O-acetylharpagide was metabolized to harpagide, which affected the pharmacokinetic profiles of harpagide when dosed as the extract. This pharmacokinetic study seems to be useful for a further clinical study of Ajuga decumbens Thunb extract.     

Antithrombotic effects of Danggui,Honghua and potential drug interaction with clopidogrel

Aim of the study

The antithrombotic effect of Danggui and Honghua, herbs commonly used in Traditional Chinese medicine to treat the syndrome corresponding to vascular thrombosis, and their potential interactions with clopidogrel were investigated.

Materials and methods

The efficacy of Danggui, Honghua alone or combination with clopidogrel was determined in three experimental models. Bleeding time and hematology parameters were measured to evaluate safety.

Results

Danggui and Honghua exhibited antithrombotic effects against venous thrombosis and pulmonary embolism. Especially in the case of venous thrombosis, the thrombus weight was decreased significantly by Danggui or Honghua when compared with control. Bleeding time and coagulation time tended to be prolonged by Danggui or Honghua, but only prothrombin time (PT) and thrombin time (TT) were augmented significantly. The combinations of Danggui plus clopidogrel and of Honghua plus clopidogrel failed to significantly enhance the antithrombotic effects of clopidogrel alone against arterial thrombosis, venous thrombosis and pulmonary embolism. However, both Danggui and Honghua significantly potentiated the prolongation caused by clopidogrel on the tail bleeding time and PT.

Conclusions

Danggui and Honghua possess antithrombotic activity and cannot potentiate the antithrombotic effect of clopidogrel. However, they significantly enhance the deleterious effect of clopidogrel on bleeding time, PT and TT.     

Inhibitory effects of Bulnesia sarmienti aqueous extract on agonist-induced platelet activation and thrombus formation involves mitogen-activated protein kinases

Ethnopharmacological relevance

B. sarmienti has long been recognized in folk medicine as a medicinal plant with various medicinal uses. Traditionally, it has been appreciated for the skin-healing properties of its essence. The bark has also been employed to treat stomach and cardiovascular disorders and reported to have antitumor, antioxidant and anti-inflammatory activities. However, information on its antiplatelet activity is limited.

Aim of the study

To examined the effects of B. sarmienti aqueous extract (BSAE) in platelet physiology.

Materials and methods

The anti-platelet activity of BSAE was studied using rat platelets for in vitro determination of the extract effect on agonist-induced platelet aggregation, ATP secretion, [Ca²⁺]_i mobilization and MAP kinase phosphorylation. The extract in vivo effects was also examined in arterio-venous shunt thrombus formation in rats, and tail bleeding time in mice.

Result

HPLC chromatographic analysis revealed that B. sarmienti extract contained (+)-catechin (C), (−)-epigallocatechin (EGC), (−)-epicatechin (EC), and (−)-epicatechin gallate (ECG). BSAE, significantly and dose dependently, inhibited collagen, thrombin, or ADP-induced platelet aggregation. The 50 percent inhibitory concentrations (IC₅₀) of the extract for collagen, thrombin and ADP-induced platelet aggregation were 45.3 ± 2.6, 100 ± 5.6 and 110 ± 4.6 μg/ml, respectively. Collagen activated ATP release and thrombin-induced intracellular Ca²⁺ concentration were reduced in BSAE-treated platelets. In addition, the extract in vivo activity showed that BSAE at 100 mg/kg significantly attenuated thrombus formation in rat extracorporeal shunt model while mice tail bleeding time was not affected. Moreover, BSAE attenuated p38 mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase 1 (JNK1) and extracellular-signal-regulated protein kinase 2 (ERK2) phosphorylations.

Conclusion

BSAE inhibits platelet activation, granule secretion, aggregation, and thrombus formation without affecting bleeding time, and that this effect is mediated by inhibition of P38, JNK1 and ERK2 phosphorylations. The ability of BSAE to inhibit platelet function might be relevant in cases involving aberrant platelet activation where the plant extract could be considered as a candidate to anti-platelet and antithrombotic agent.     

In vitro antioxidant, antiplatelet and anti-inflammatory activity of Carpobrotus rossii (pigface) extract

Ethnopharmacological relevance

Carpobrotus rossii (CR) has a history of use as a food and therapeutic agent by Australian indigenous peoples and early European settlers and is believed to contain a number of pharmacologically active polyphenolic compounds.

Aims of the study

Oxidation of low density lipoprotein (LDL), platelet aggregation, and inflammation contribute to the development and progression of atherosclerosis. The aim of the present study was to investigate the antioxidant, antiplatelet and anti-inflammatory activity of CR extract using human blood components.

Materials and methods

An assay employing in vitro copper-induced oxidation of serum lipids was used to assess antioxidant activity of CR extract (and tannin, flavonoid and pre- and post-flavonoid fractions). The effects of CR extract on ADP- and collagen-induced platelet aggregation, and on basal (unstimulated) and lipopolysaccharide (LPS)- and phytohaemagglutinin A (PHA)-stimulated cytokine release from peripheral blood mononuclear cells (PBMC) were also investigated.

Results

CR extract increased the lag time of serum oxidation (maximum of ∼4-fold at 20 μg/ml) in a concentration-dependent manner. The antioxidant activity resided only in the tannin and post-flavonoid fractions. CR had no effect on ADP-induced platelet aggregation, but significantly decreased collagen-induced platelet aggregation. LPS, but not PHA, significantly increased the release of IL-1β and TNF-α from PBMC. CR extract alone inhibited monocyte chemoattractant protein (MCP)-1 release and in the presence of LPS, inhibited IL-10, TNF-α and MCP-1 release compared to LPS alone.

Conclusion

CR has significant in vitro antioxidant, antiplatelet and, potentially, anti-inflammatory activity.     

Dragon's Blood extract has antithrombotic properties, affecting platelet aggregation functions and anticoagulation activities

Ethnopharmacological relevance

Dragon's Blood from Dracaena cochinchinensis (Lour.) S.C. Chen (Yunnan, China), as a traditional Chinese medicinal herb, was shown to have certain antithrombotic effects. A new preparation process was used to extract effective components from Dragon's Blood. A 95% ethanol extract A (EA) and a precipitate B (PB) fraction were obtained and compared. Reliability of the preparation process was validated by pharmacodynamic experiments.

Materials and methods

A rat/mouse thrombosis and blood stasis model was developed for this study, and EA and PB effects on thrombosis, platelet functions and blood coagulation activities were analyzed.

Results

It was observed that the EA fraction had significantly better inhibitory effects than the PB fraction on thrombosis (p < 0.05), platelet aggregation function (p < 0.01) and anticoagulation activity (p < 0.05-0.01).

Conclusions

The results obtained here showed that EA fraction from Dragon's Blood contained pharmacologically effective compounds with antithrombotic effects, partially improving platelet function and anticoagulation activity.     

The Operculina macrocarpa (l.) urb. (jalapa) tincture modulates human blood platelet aggregation

Ethnopharmacological relevance

Operculina macrocarpa is an ornamental climbing plant of the Northeastern Brazil extensively used in traditional medicine as depurative of the blood and for the treatment of thrombosis. To investigate the antiplatelet and anticoagulant potential of Operculina macrocarpa and to determine the possible mechanisms of action.

Material and methods

The Operculina macrocarpa tincture (OMT) was characterized by the polyphenol content and chromatographic profile established by HPLC with detection and quantification of three phenol acids (caffeic, clorogenic and gallic acids). The human platelet aggregation was induced in vitro by the agonists ADP, collagen, thrombin, epinephrine or arachidonic acid, and the antiplatelet effect of OMT was evaluated in the presence or absence of aspirin (a nonselective inhibitor of cyclooxygenase), pentoxifylline (a phosphodiesterase inhibitor), ticlopidine (a P2Y₁₂ purinoceptor antagonist) or ODQ (a selective inhibitor of guanilate cyclase). The effect of OMT on the partial thromboplastin time, prothrombin time and bleeding time were investigated on human or rat plasma.

Results

The strongest antiplatelet effect of OMT (50–400 µg/mL) was observed on the ADP- induced aggregation with inhibitions up to 55%, while among others agonists (epinephrine, collagen, thrombin and arachidonic acid) maximal inhibitions reached by OMT (200 µg/mL) were on platelet aggregation induced by collagen (18%) or epinephrine (20%). The antiplatelet effect of OMT (400 µg/mL) was comparable to aspirin, a nonspecific inhibitor of cyclooxygenase. The ticlopidine and pentoxifylline increased 5.1 and 3.8 fold the inhibitory effect of OMT on ADP-induced platelet aggregation, respectively. On the other hand, l-arginine, ODQ and aspirin showed a slightly or no effect on antiplatelet effect of OMT. The bleeding time in rats was significantly increased by OMT, but the tincture did not interfere on the activated partial thromboplastin or prothrombin time in human plasma.

Conclusions

This study showed that the tincture of Operculina macrocarpa has antiplatelet effect that cannot be attributed to a single biochemical mechanism and at least part of it cannot be related to the OMT inhibition of P2Y₁₂ purinergic receptors.     

Immunomodulatory effects of crude phenylethanoid glycosides from Ligustrum purpurascens

Ethnopharmacological relevance

Ligustrum purpurascens, named as “Ku ding cha”, has been used as a kind of functional tea in southern China for about two thousand years, which has the effects on diuresis, anti-hypertension, weight-loss and anti-inflammation.

The aim of the study

This study was aimed to investigate the immune enhancement effects of the crude phenylethanoid glycosides (CPGs) from Ligustrum. Purpurascens on mice and analyze the chemical profiles of phenylethanoid glycosides in the CPGs.

Materials and methods

The immune functions enhancing potential of CPGs was determined using serum hemolysin antibody, phagocytosis, splenocyte antibody production, and NK cells activity assays. The contents of five major constituents in the crude glycosides of Ligustrum purpurascens were determined by using liquid chromatography, other five glycosides were deduced according to their UV and MS spectra compared with the literature as well.

Results

In the immunizing experiment, mice treated with different doses of CPGs showed an increase (p<0.01) in the haemagglutination titre compared with the control group. The increases (p<0.05) were found to be significant at doses of 440 mg/kg and 1.32 g/kg in the experiments of antibody production of spleen cells, MΦ phagocytosis of chicken RBCs and NK cell activity. Further chemical characterization yielded 10 constituents from CPGs, five glycosides were quantified by HPLC and the structures of other five compounds were speculated according to their UV and MS spectra.

Conclusion

The results suggested that phenylethanoid glycosides from Ligustrum purpurascens have immunomodulatory effects on mice.     

Neuroprotective activity of Matricaria recutita Linn against global model of ischemia in rats

Ethnopharmacological relevance

Traditionally, the whole plant is used for various diseases, including neuronal disorders.

Aim of the study

To evaluate the neuroprotective effect of Matricaria recutita L. against global cerebral ischemia/reperfusion (I/R) injury-induced oxidative stress in rats.

Materials and methods

Neuroprotective activity was carried out by global cerebral ischemia on Sprague–Dawley rats by bilateral carotid artery (BCA) occlusion for 30 min followed by 60 min reperfusion. The antioxidant enzymatic and non-enzymatic levels were estimated along with cerebral infarction area and histopathological studies.

Results

The Matricaria recutita L. methanolic extract showed dose-dependent neuroprotective activity by significant decrease in lipid peroxidation (LPO) and increase in the superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and total thiol levels in extract treated groups as compared to ischemia/reperfusion group. Cerebral infarction area was significantly reduced in extract treated groups as compared to ischemia/reperfusion group.

Conclusion

The methanolic extract of Matricaria recutita L. showed potent neuroprotective activity against global cerebral ischemia/reperfusion injury-induced oxidative stress in rats.     

Anti-inflammatory compounds of “Qin-Jiao”, the roots of Gentiana dahurica (Gentianaceae)

Ethnopharmacological relevance

“Qin-Jiao” is a well-known traditional Chinese medicinal (TCM) herb having been used generally for fighting rheumatoid arthritis (RA) since ancient times. The root of Gentiana dahurica Fisch (Gentianaceae) is one of the four officially validated “Qin-Jiao” as listed in the Chinese Pharmacopoeia. In addition, it is a common Tibetan medicinal herb used for the treatment of tonsillitis, urticaria, and RA, while the flowers have been used as a Mongolian herb for curing cough sore throat and eliminating the phlegm due to its anti-inflammatory effect.

Aim of the study

The aim of the study was to characterize the anti-inflammatory compounds in “Qin-Jiao”, on the basis of detailed investigation on not only the phytochemical study of Gentiana dahurica, but also the bioactive evaluation on compounds obtained presently and previously from different “Qin-Jiao” origins and Gentiana species.

Materials and methods

The ethanol extract of air-dried roots of Gentiana dahurica was suspended into H₂O and extracted with EtOAc and n-BuOH, successively. Repeated column chromatography (CC) and semi-preparative HPLC were carried out on each of the fractions. The isolated compounds were determined by detailed spectroscopic analysis and acidic hydrolysis. Anti-inflammatory activities of 18 isolates, together with 12 typical compounds obtained previously by our group from the other “Qin-Jiao” origins (Gentiana crassicaulis, Gentiana straminea) and Gentiana rigescens, were tested by inhibitory effects on LPS-induced NO production in macrophage RAW264.7 cells and TPA-induced cyclooxygenases-2 and -1 (COXs-2/1) production on zebrafish model.

Results

A new lignan glycoside (1) was identified, together with 20 known compounds, including 10 iridoid glycosides (2–11), three steroids (12–14), four lignans (15–18), one phenylpropanoid (19) and two triterpenes (20–21). Anti-inflammatory bioassay showed that only compound 21 displayed potential inhibitory effect on NO production (IC₅₀=16.85 μM), while 20 tested compounds had inhibitory activities on COXs-2/1. Among them, the triterpenoid 21 was the most active compound with an inhibitory value of 78% at a concentration of 30 μM. All the tested compounds showed no cytotoxicity on five human cancer cell lines (40 μM) and zebrafish (30 μM), except for 21 displaying weak cytotoxicity on human myeloid leukemia HL-60 (IC₅₀=16.43 μM).

Conclusion

Most of compounds particularly iridoid glycosides from “Qin-Jiao” display potential inhibitory effect on COXs-2/1. The results support the historical importance of the well-known TCM herb, “Qin-Jiao”, having been commonly used for fighting RA. As major components, the bioactive iridoid glycosides should play important role in the anti-inflammatory effect of “Qin-Jiao”. Although further research will be required to evaluate the selective activities of the COXs-2/1 inhibitors, this work validates the medicinal use of “Qin-Jiao” and provides information for different “Qin-Jiao” origins having different treating effects on RA.     

Taoren-Honghua herb pair and its main components promoting blood circulation through influencing on hemorheology, plasma coagulation and platelet aggregation

Ethnopharmacological relevance

Persicae Semen (Taoren) and Carthami Flos (Honghua) used in pair which is named as Taoren-Honghua (TH) herb pair has been used in traditional Chinese medicine (TCM) for promoting blood circulation to dissipate blood stasis for many years in China.

Aim of the study

This paper investigated the effects of TH and its main components amygdalin and hydroxysafflor yellow A (HSYA) on hemorheological disorders of blood stasis in rats.

Materials and methods

Rats were randomly divided into seven groups (control group, model group, TH group, amygdalin group, HSYA group, amygdalin + HSYA group, and aspirin group) with eight animals in each, whose gender was equally distributed throughout groups. All treatments were performed by gavage and administered seven times with an interval of 12 h. After the fifth administration, the model rats except those in control group with blood stasis were established by being placed in ice-cold water during the interval between two injections of adrenaline hydrochloride (Adr); and blood samples were collected 30 min after the last administration on the following day.

Results

TH could significantly decrease whole blood viscosity (WBV), plasma viscosity (PV) and packed cell volume (PCV). It also significantly prolonged thrombin time (TT) and thromboplastin time (APTT), increased prothrombin time (PT) and lowered fibrinogen content (FIB). HSYA which significantly decreased WBV and PV had no effect on plasma coagulation parameters. Amygdalin could significantly decrease PV, prolong APTT and decrease FIB, showing few effects on WBV. TH and its main components amygdalin and HSYA could significantly reduce platelet aggregation and protect vascular endothelial cells. Based on the above results, amygdalin and HSYA were responsible for the main curative effects of TH and usually had synergetic effects, such as decreasing PV and platelet aggregation percentage.

Conclusions

The study may provide scientific information to further understanding of the mechanism(s) of TH and its main components in activating blood circulation to dissipate blood. It may also create valuable insight into the possible effects and utilization of TH and its components as a feasible alternative therapeutic agent for patients with hemorheological disorders.     

Traditionally used Veronica officinalis inhibits proinflammatory mediators via the NF-κB signalling pathway in a human lung cell line

Ethnopharmacological relevance

Extracts from Veronica officinalis L. are traditionally used for the treatment of lung diseases; however, the effective compounds and the mode of action are still unknown.

Aim of the study

Here we analyzed the effects of a standardized Veronica extract on genes expression and signalling protein production associated with the development of inflammatory lung diseases.

Material and methods

The degranulation capacity of primary mast cells, as well as gene expression and release of inflammatory mediators from human lung epithelial cells (A549 cells) were analyzed in relation to the synthetic drugs azelastine and dexamethasone. Gene and protein expression of cyclooxygenase-2 were investigated by semi-quantitative RT-PCR and western blotting, respectively. The involvement of phosphorylated mitogen-activated protein kinases and NF-κB signaling in regulation of these molecules were characterized by western blotting and electrophoretic mobility shift assays. Characteristic extract components were identified by LC–MS and verminoside was quantified by HPLC analysis.

Results

We demonstrated that Veronica officinalis has a small influence on the degranulation capacity of mast cells but rather inhibits gene and protein expression of the chemokine eotaxin in A549 lung epithelial cells, which is essential for recruitment of inflammatory-associated cells in lung diseases. Furthermore, release of the inflammatory mediator PGE₂ was diminished through inhibition of COX-2 expression via the NF-κB signaling pathway in TNF-α-activated A549 cells. Phytochemical analysis identified verproside and verminoside as the most abundant iridoid glycosides.

Conclusion

Our results are a contribution to explaining the observed anti-inflammatory effects of Veronica offcinalis extract on a molecular level. However, its clinical potency has at first to be proven in animals and subsequently in clinical trials.     

Effects of Tribulus terrestris on endocrine sensitive organs in male and female Wistar rats

Aim of the study

Investigate the possible effects of Tribulus terrestris (TT) on endocrine sensitive organs in intact and castrated male rats as well as in a post-menopausal rat model using ovariectomized females.

Materials and methods

Three different dose levels of TT (11, 42 and 110 mg/kg/day) were administered to castrated males for 7 days and to intact males and castrated females for 28 days. In addition to TT treatment, all experiments also included a group of rats treated with dehydroepiandrosterone (DHEA). In experiments using castrated males and females we also used testosterone and 17α-ethynylestradiol, respectively, as positive controls for androgenicity and estrogenicity.

Results

Neither DHEA nor TT was able to stimulate androgen sensitive tissues like the prostate and seminal vesicle in both intact and castrated male rats. In addition, administration of TT to intact male rats for 28 days did not change serum testosterone levels as well as did not produce any quantitative change in the fecal excretion of androgenic metabolites. However, a slight increase in the number of homogenization-resistant spermatids was observed in rats treated with 11 mg/kg/day of TT extract. In ovariectomized females, TT did not produce any stimulatory effects in uterine and vaginal epithelia.

Conclusions

Tribulus terrestris was not able to stimulate endocrine sensitive tissues such as the prostate, seminal vesicle, uterus and vagina in Wistar rats, indicating lack of androgenic and estrogenic activity in vivo. We also showed a positive effect of TT administration on rat sperm production, associated with unchanged levels of circulating androgens.     

Antiplatelet effects of Spatholobus suberectus via inhibition of the glycoprotein IIb/IIIa receptor

Ethnopharmacological relevance

The vine stem of Spatholobus suberectus is a widely used blood-activating and stasis-dispelling medicine for the treatment of diseases related to blood stasis syndrome in traditional medicine in Korea, Japan, and China.

Aim of the study

To demonstrate the clinical effects of Spatholobus suberectus against blood stasis syndromes using in vitro and in vivo platelet aggregation studies and to investigate its exact mechanisms.

Materials and methods

We extracted vine stems of Spatholobus suberectus, using 95% EtOH (SSE) and investigated its antiplatelet activity on platelet aggregation induced by collagen and ADP in human platelet-rich plasma (PRP). For the mechanism study, a glycoprotein IIb/IIIa (GP IIb/IIIa) assay using flow cytometric analysis and a thromboxane A₂ (TXA₂) assay were performed. In addition, we investigated the effects of SSE in a thromboembolic mouse model.

Results

SSE significantly inhibited ADP- and collagen-induced platelet aggregation in human PRP concentration-dependently without affecting plasma clotting time. It also significantly inhibited fibrinogen binding to the GP IIb/IIIa receptor and partly inhibited the formation of TXA₂. In the in vivo study, oral administration of SSE dose-dependently suppressed the death of thromboembolism model mice induced by intravenous injection of collagen plus epinephrine.

Conclusions

SSE showed antiplatelet activity without anticoagulant effects mainly through the inhibition of fibrinogen binding to the GP IIb/IIIa receptor. Our current results support the clinical usage of SSE in the East Asian region treating atherothrombotic diseases and may represent a new natural source to develop antiplatelet agents.     

疏血通与阿司匹林合用能够改善脑缺血再灌注损伤后凝血纤溶系统

目的：观察疏血通(SXT)与阿司匹林合用对脑缺血再灌注损伤大鼠凝血及纤溶系统的影响。 方法：选用经典的线栓法制备大鼠局灶性脑缺血再灌注损伤模型。将50只雄性SD大鼠随机分为假手术组、脑中动脉栓塞（MCAO/R）模型组、阿司匹林(10 mg/kg)组、疏血通(0.6 ml/kg)组、疏血通(0.6 mg/kg)+阿司匹林(10 mg/kg)组。按照Longa的5级评分方法进行神经功能缺损评分;干湿重法测定脑组织含水量;四氮唑红（TTC）染色测定脑梗塞体积;腹主动脉取血检测血小板聚集率（MPAR）、凝血四项并用酶联免疫法检测大鼠血浆中血小板CD61、CD62p、 6-酮前列腺素F1α(6-keto-PGF1α)、抗凝血酶Ⅲ(AT-Ⅲ)、D-二聚体(D-dimer)、纤溶酶原激活物抑制剂-1(PAI-1)、组织因子 (TF)、组织型纤溶酶原激活物(t-PA)、血小板血栓烷素B2 (TXB2)、血管性血友病因子（vWF）的含量。 结果：疏血通与阿司匹林合用能够改善MCAO/R诱导大鼠神经功能缺损,减轻脑水肿,缩小脑梗死体积。与假手术组相比较纤维蛋白原（FIB）、6-PGF1α、AT-Ⅲ、t-PA均有显著的下降;与模型组相比较,疏血通与阿司匹林合用组的上述指标都有明显上调。模型组的凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、凝血酶时间（TT）、CD61、CD62p、D-dimer、PAI-1、TF、TXB2和vWF与假手术组相比都有明显上升;经疏血通与阿司匹林处理组的上述指标都有明显下降。合用效果与单用药比较,差异具有显著性。与假手术组比较,MPAR显著升高;阿司匹林治疗后,MPAR显著下调;疏血通与阿司匹林合用给药组MPAR下调水平降低。 结论：疏血通与阿司匹林合用能抑制血小板活化,调节血小板最大聚集率,改善凝血功能和纤溶系统。