Deciphering molecular mechanism underlying antileishmanial activity of Nyctanthes arbortristis, an Indian medicinal plant

Ethnopharmacological relevance

Nyctanthes arbortristis L. (Oleaceae) is widely used in the traditional medicine of India. The plant is shown to have antibacterial and antileishmanial activities.

Aim of the study

Evaluation of iridoid glucosides from the plant as inhibitor of trypanothione reductase (TryR), a validated drug target enzyme of the Leishmania parasite. The study contributes towards understanding mechanism of antileishmanial effect of the plant.

Materials and methods

TryR of Leishmania parasite is expressed and purified. Iridoid glucosides are isolated from the plant and tested as inhibitor of TryR enzyme of the parasite.

Results

Inhibitory constant (K_i) of various iridoid glucosides ranges from 3.24 ± 0.05 μM to 6.49 ± 0.05 μM. Thus, the molecular mechanism underlying antileishmanial activity of these compounds is mediated through inhibition of TryR.

Conclusion

The current study also points out towards potential application of iridoid glucosides as novel drugs against the disease.     

Effect of Emblica officinalis (fruit) against UVB-induced photo-aging in human skin fibroblasts

Ethnopharmacological relevance

Emblica officinalis fruit (EO), commonly known as Amla is a reputed traditional medicine and functional food used in Indian subcontinent. It has long been used in Indian folk medicine to treat liver diseases, stomach ulcers, inflammatory diseases, metabolic disorders, geriatric complaints, skin disorders and beauty care.

Aim of the study

Recently, it has been shown to promote pro-collagen content and inhibit matrix metalloproteinase levels in skin fibroblast. The aim of the present study was to investigate the efficacy of EO to inhibit UVB-induced photo-aging in human skin fibroblasts.

Materials and methods

Mitochondrial activity of human skin fibroblasts was measured by MTT-assay. Quantifications of pro-collagen 1 and matrix metalloproteinase 1 (MMP-1) release were performed by immunoassay techniques. Hyaluronidase inhibition assay was studied in vitro using bovine testicular hyaluronidase and human umbilical cord hyaluronic acid. Cell cycle analysis was performed by flowcytometry using propidium iodide.

Results

EO stimulated, the otherwise UVB inhibited cellular proliferation and protected pro-collagen 1 against UVB-induced depletion via inhibition of UVB-induced MMP-1 in skin fibroblasts (10-40 μg/mL, p > 0.001). EO exhibited inhibitory activity of hyaluronidase (10-40 μg/mL, p > 0.001). Treatment with EO also prevented UVB disturbed cell cycle to normal phase.

Conclusion

The results of the present study suggests that EO effectively inhibits UVB-induced photo-aging in human skin fibroblast via its strong ROS scavenging ability and its therapeutic and cosmetic applications remain to be explored.     

Antidepressant effect of Valeriana wallichii patchouli alcohol chemotype in mice: Behavioural and biochemical evidence

Ethnopharmacological relevance

Valeriana wallichii DC, an ayurvedic traditional medicine has now been shown to exist chemically as three distinct chemotypes. The study aimed to investigate the antidepressant effect of dichloromethane extract of Valeriana wallichii patchouli alcohol chemotype.

Materials and methods

Antidepressant effect of dichloromethane extract of Valeriana wallichii (10, 20 and 40 mg/kg, p.o.) using forced swim test, was determined in both acute and chronic study. The neurotransmitter levels were estimated in mouse forebrain after two weeks of dosing.

Results

Single administration of extract (40 mg/kg) significantly inhibited the immobility period in mice (p < 0.05). Similarly, chronic administration of extract (20 and 40 mg/kg) significantly reduced the immobility period and significantly increased the levels of norepinephrine and dopamine in mouse forebrain (p < 0.05).

Conclusions

The extract demonstrated antidepressant effect and significantly increased the norepinephrine and dopamine levels in forebrain.     

Consequences of subchronic exposure to ethanolic extract from fruits and leaves of Schinus molle var. areira L. in mice

Aim of the study

Several extracts of Schinus molle var. areira L. plant proved to be useful for the treatment of different pathologies and for the control of insect pest. Due to these potential uses, it is necessary to study their safety. In this work, we evaluated the effects of subchronic exposure to ethanolic extracts from leaves and fruits of Schinus molle var. areira in mice.

Materials and methods

The plant extract was added to the diet at 1 g/kg body weight/day for 90 days. At the end of the exposure, behavioral and functional parameters in a functional observational battery and motor activity in an open field were assessed. Finally, several biochemical and histopathological studies were realized.

Results

The exposure to extract from leaves produced an increase in the number of rearings in the open field and of urine pools in the functional observational battery. On the other hand, the exposure to extract from fruits produced an increase in the neutrophil count and a decrease in the lymphocyte count and in the total cholesterol levels. None of the exposures affected the different organs evaluated.

Conclusions

Our results suggest that subchronic exposure to ethanolic extracts from leaves and fruits of Schinus molle var. areira should be potentially useful in the treatment of lipid pathologies and safe to use.     

Analgesic and anti-inflammatory activities of 11-O-galloylbergenin

Aims of the study

Current study was designed to explore the analgesic and anti-inflammatory effects of a constituent isolated from Mallotus philippinensis, in order to validate its folk use.

Materials and methods

11-O-galloylbergenin was isolated from ethanolic extract of Mallotus philippinensis. Analgesic and anti-inflammatory activities of the test compound were assessed using formalin test and carrageenan-induced paw edema models.

Results

11-O-galloylbergenin showed significant analgesic activity at doses of 20 and 40 mg/kg against formalin test in rats. Similarly, 11-O-galloylbergenin exhibited significant anti-inflammatory activity in carrageenan-induced paw edema model at doses of 10, 20 and 30 mg/kg.

Conclusion

11-O-galloylbergenin has demonstrated its significant potential to be further investigated for its discovery as a new lead compound for management of pain and inflammation.     

Protective effect of Ilex latifolia, a major component of "kudingcha", against transient focal ischemia-induced neuronal damage in rats

Aims of the study

Ilex latifolia (Aquifoliaceae), a primary component of “kudingcha”, has been used in Chinese folk medicine to treat various kinds of diseases including headaches, inflammatory diseases, and cardiac ischemic injury. The present study investigated the protective effect of the ethanol extract of Ilex latifolia against transient, focal, ischemia-induced neuronal damage.

Materials and methods

Transient focal ischemia was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/reperfusion) in rats. After MCAO/reperfusion, brain infarction and neuronal death were measured by triphenyltetrazolium chloride and hematoxylin and eosin staining, respectively. Glutathione concentration and lipid peroxidation rate were measured. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), cyclooxygenase 2 (COX-2), and anti-apoptotic and pro-apoptotic proteins were detected by Western blot.

Results

Ilex latifolia (50-200 mg/kg) significantly reduced MCAO/reperfusion-induced infarction and edema formation, neurological deficits, and brain cell death. Depletion of glutathione level and lipid peroxidation induced by MCAO/reperfusion were inhibited by administration of Ilex latifolia. The increase of phosphorylated MAPKs, COX-2, and proapoptotic proteins and the decrease of antiapoptotic protein in MCAO/reperfusion rats were significantly inhibited by treatment with Ilex latifolia.

Conclusion

Ilex latifolia ameliorated ischemic injury induced by MCAO/reperfusion in rats, and this neuroprotective effect might be associated with its anti-apoptotic effect, resulting from anti-oxidative and anti-inflammatory actions.     

Pharmacological characterization of the diuretic effect of Hibiscus sabdariffa Linn (Malvaceae) extract

Ethnopharmacological relevance

Hibiscus sabdariffa L. (Malvaceae) populary known in Mexico as “Jamaica”, “flor de Jamaica”, has widely used in Mexican Traditional Medicine as antihypertensive and diuretic, although the latter activity has been reported the present work show evidence about the diuretic, natriuretic and potassium-sparing effects.

Aim of the study

To evaluate the diuretic activity of Hibiscus sabdariffa aqueous extract on in vivo and in situ models.

Materials and methods

The Hibiscus sabdariffa aqueous extract was administrated in increasing doses and evaluated the diuresis produced and disposal of electrolytes. Moreover, in isolated kidney was determined the renal filtration rate with plant extract, furosemide and amiloride.

Results

The yield of Hibiscus sabdariffa aqueous extraction was 28.3% and the chemical standardization from 1 g of extract was: 56.5 mg delphinidin-3-O-sambubioside, 20.8 mg/g cyanidin-3-O-sambubioside, 3.2 mg/g quercetin, 2.1 mg/g rutin and 2.7 mg/g chlorogenic acid. The diuretic and natriuretic effect of Hibiscus sabdariffa aqueous extract showed a dose-dependent behavior. The pharmacological constants of natriuretic effect was ED50 = 86 mg/kg and Emax = 0.9 mEq/100 g/5 h. In the model of kidney in situ was observed that renal filtration increased 48% with the aqueous extract of Hibiscus sabdariffa and an additive effect when was perfuse with furosemide.

Conclusion

The compound presents in Hibiscus sabdariffa as quercetin had effect on the vascular endothelium causing oxide nitric release, increasing renal vasorelaxation by increasing kidney filtration. Therefore, the diuretic effect of Hibiscus sabdariffa may be mediated by nitric oxide release.     

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

Aim of the study

In order to evaluate the antimalarial potential of traditional remedies used in Peru, Indigenous and Mestizo populations from the river Nanay in Loreto were interviewed about traditional medication for the treatment of malaria.

Materials and methods

The survey took place on six villages and led to the collection of 59 plants. 35 hydro-alcoholic extractions were performed on the 21 most cited plants. The extracts were then tested for antiplasmodial activity in vitro on Plasmodium falciparum chloroquine resistant strain (FCR-3), and ferriprotoporphyrin inhibition test was also performed in order to assume pharmacological properties.

Results

Extracts from 9 plants on twenty-one tested (Abuta rufescens, Ayapana lanceolata, Capsiandra angustifolia, Citrus limon, Citrus paradise, Minquartia guianensis, Potalia resinífera, Scoparia dulcis, and Physalis angulata) displayed an interesting antiplasmodial activity (IC₅₀ < 10 μg/ml) and 16 remedies were active on the ferriprotoporphyrin inhibition test.

Conclusions

The results give scientific validation to the traditional medical knowledge of the Amerindian and Mestizo populations from Loreto and exhibit a source of potentially active plants.     

Antinociceptive and antiinflammatory activities of Adiantum latifolium Lam.: Evidence for a role of IL-1β inhibition

Aim of study

Adiantum, one of the most widely distributed genera of the family Pteridaceae, is employed in folk medicine worldwide. Adiantum latifolium Lam. has been used in Latin American traditional medicine as anxiolytic, analgesic and antiinflammatory. The present study investigates the antinociceptive and antiinflammatory properties of the methanolic extract of Adiantum latifolium (MEA) in animal models of pain and inflammation to confirm its medicinal use.

Material and methods

The antinociceptive and antiinflammatory activities of MEA were evaluated using the writhing, formalin, and tail-flick tests, carrageenan-induced paw edema and arachidonic acid-induced ear edema. Mice motor performance was evaluated in the rota rod test and the acute toxicity evaluated over 14 days.

Results

Intraperitoneal (1-100 mg/kg) or oral (100-400 mg/kg) administration of MEA produced a dose-related inhibition of acetic acid-induced writhing in mouse. Furthermore, treatment with MEA (100 mg/kg) inhibited both the early and late phases of formalin-induced hypernociception. In contrast, MEA (100 mg/kg/IP) did not prevent the thermal nociception in the tail-flick test. In addition, MEA (100 and 200 mg/kg/IP) inhibited important events related to the inflammatory response induced by carrageenan or arachidonic acid, namely local edema and increase in tissue interleukin-1β levels. MEA (300 mg/kg/IP)-treated mice did not show any motor performance alterations. Over the study period of 14 days, there were no deaths or toxic signs recorded in the group of mice given 1000 mg/kg of MEA.

Conclusion

The results demonstrate that Adiantum latifolium has antinociceptive and antiinflammatory activities, acting through the inhibition of IL-1β production.     

Acute and sub-chronic oral toxicity studies of an aqueous stem bark extract of Pterocarpus soyauxii Taub (Papilionaceae) in rodents

Pterocarpus soyauxii Taub (Papilionaceae) is used in Cameroonian traditional medicine and pharmacopoeia to treat hypertension, diabetes, gastrointestinal parasitizes and cutaneous diseases.

Aim of the study

The present investigation was carried out to evaluate the safety of an aqueous stem bark extract of Pterocarpus soyauxii by determining toxicity after acute and sub-chronic oral administration in male and female rodents.

Materials and methods

The acute toxicity test was conducted in mice. An aqueous extract of barks was administrated by gavage in single doses of 2.5-12.5 g/kg. General behaviour and mortality were examined for up to 7 days. The sub-chronic toxicity test was performed in rats. The plant extract was administered by daily gavage of 150-600 mg/kg for 42 days. Body weight, food and water intakes were followed weekly. Haematological, biochemical and organ parameters were determined at the end of the 42-day administration.

Results

In the acute study in mice, oral administration of the aqueous extract of Pterocarpus soyauxii caused dose-dependent general behaviour adverse effects and mortality. The no-observed adverse effect level (NOAEL) of the extract was 5.0 g/kg. The lowest-observed adverse effect level (LOAEL) was 7.5 mg/kg. Mortality increased with the dose, LD₅₀ was > 10.75 g/kg for the mouse. In the sub-chronic study in rats, daily oral administration of the aqueous extract of Pterocarpus soyauxii did not result in death or significant changes in haematological or biochemical parameters, excepted increased hepatic catalase activity (P < 0.05) at the dose of 600 mg/kg. No alteration was observed in body weight, food and water intake. Liver, kidney, lung and pancreas histopathology did not reveal morphological alteration.

Conclusions

The results showed that the aqueous stem bark extract of Pterocarpus soyauxii Taub had very low toxicity in oral acute high dose administration and no toxicity in oral sub-chronic low dose administration and indicate that the plant could be considered safe for oral medication.     

Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors

Aim of the study

A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors.

Materials and methods

Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM.

Results

From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC₅₀ = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition.

Conclusions

Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors.     

Anti-inflammatory activity of Terminalia paniculata bark extract against acute and chronic inflammation in rats

Ethnopharmacological relevance

Terminalia paniculata Roxb. (Family-Combretaceae) is a wild tree commonly used in traditional ayurvedic medicine for the treatment of inflammation of parotid glands and in menstrual disorders.

Aim of the study

To explore the folk use of Terminalia paniculata on pharmacological grounds to evaluate the scientific basis of anti-inflammatory activity.

Materials and methods

The anti-inflammatory activity of Terminalia paniculata was studied against carrageenan-induced hind paw edema, air pouch inflammation and complete Freund's adjuvant (CFA)-induced arthritis in rats. The aqueous extract of Terminalia paniculata bark (TPW) was administered at the concentrations of 100, 200 and 400 mg/kg body weight.

Results

TPW showed significant (p < 0.05) anti-inflammatory activity by reducing the edema volume in carrageenan-induced paw edema in rats. Further, TPW (400 mg/kg) also reduced the carrageenan-induced leukocyte migration (50.92 ± 5.71%) and myeloperoxidase activity (49.31 ± 5.24%) in air pouch exudates. TPW (200 mg/kg) exhibits anti-rheumatic and analgesic activities by improving the altered haematological milieu (ESR, CRP, RF, WBC, RBC and Hb) and also by inhibiting the flexion scores and radiographic changes in CFA-induced arthritis. This extract also had significant (p < 0.05) effects on the occurrence of secondary lesions compared to CFA control.

Conclusions

Terminalia paniculata bark may be a potential preventive or therapeutic candidate for the treatment of chronic inflammation and arthritis.     

Antiosteoporotic activity of Davallia formosana

Ethanopharmacological relevance

In Taiwanese folk medicine, Davallia formosana is used to treat bone diseases, including osteoporosis.

Aim

This study evaluated the anti-osteoporotic effect of ethanolic extract derived from Davallia formosana (DFE).

Materials and methods

In this in vitro study, we investigated the inhibitory action of DFE on RANKL-stimulated osteoclastogenesis. The in vivo effects of DFE on bone metabolism were evaluated using ovariectomized (OVX) rats orally administered DFE (200, 500 mg/kg), alendronate (2.5 mg/kg, three times a week) or its vehicle for 12 weeks.

Results

This in vitro study demonstrated that DFE inhibited osteoclast differentiation, and also isolated the active component, (−)-epicatechin 3-O-β-d-allopyranoside (ECAP). DFE did not affect the body or vaginal weight in OVX rats. The bone mineral density and bone calcium content in OVX rats were lower in the control group showing that DFE was able to prevent significant bone loss. In addition, the three point bending test and the microcomputer tomography scanning showed that DFE treatment enhanced bone strength and inhibited the deterioration of trabecular microarchitecture. In the biochemical assay, DFE decreased urinary deoxypyridinoline and calcium concentrations, but did not inhibit serum alkaline phosphatase activities, indicating that it ameliorated bone loss via inhibition of bone reabsorption.

Conclusions

These results suggest that DFE may represent a useful remedy for the treatment of bone reabsorption diseases such as osteoporosis. In addition, ECAP could be used as a marker compound to control the quality of DFE.     

Hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients

Ethnopharmacological relevance

Bitter melon (Momordica charantia L.) has been widely used as an traditional medicine treatment for diabetic patients in Asia. In vitro and animal studies suggested its hypoglycemic activity, but limited human studies are available to support its use.

Aim of study

This study was conducted to assess the efficacy and safety of three doses of bitter melon compared with metformin.

Materials and methods

This is a 4-week, multicenter, randomized, double-blind, active-control trial. Patients were randomized into 4 groups to receive bitter melon 500 mg/day, 1000 mg/day, and 2000 mg/day or metformin 1000 mg/day. All patients were followed for 4 weeks.

Results

There was a significant decline in fructosamine at week 4 of the metformin group (−16.8; 95% CI, −31.2, −2.4 μmol/L) and the bitter melon 2000 mg/day group (−10.2; 95% CI, −19.1, −1.3 μmol/L). Bitter melon 500 and 1000 mg/day did not significantly decrease fructosamine levels (−3.5; 95% CI −11.7, 4.6 and −10.3; 95% CI −22.7, 2.2 μmol/L, respectively).

Conclusions

Bitter melon had a modest hypoglycemic effect and significantly reduced fructosamine levels from baseline among patients with type 2 diabetes who received 2000 mg/day. However, the hypoglycemic effect of bitter melon was less than metformin 1000 mg/day.     

Protective effects of methanolic extract of Hedyotis puberula (G. Don) R. Br. ex Arn. against experimentally induced gastric ulcers in rat

Aim of the study

This study was aimed to evaluate the antiulcer activity of the whole plants of Hedyotis puberula (G. Don) R. Br. ex Arn.

Materials and methods

Gastroprotective potential of the Hedyotis puberula methanol extract (200 and 400 mg/kg body weight) was studied on indomethacin (IND), ethanol and pyloric ligation (PL)-induced gastric ulcer models in rats.

Results

The treatment with Hedyotis puberula extract at 400 mg/kg p.o. protected the rats against the ulceration which was comparable to the reference drug omeprazole. Pretreatment with extract protected rats from gastric lesion development by way of increased pH and decreased volume, acidity and pepsin content of gastric secretion. Furthermore, total carbohydrate: protein ratio of the gastric juice were noticeably increased in pretreated rats.

Conclusion

Results of our study showed that Hedyotis puberula possess significant gastroprotective activity and validate the folklore claim.     

Bronchospasm potentiating effect of methanolic extract of Ficus religiosa fruits in guinea pigs

Ethnopharmacological relevance

The sacred tree Peepal (Ficus religiosa family: Moraceae) has numerous therapeutic utility in folk medicine.

Aim of the study

It has been reported to be used in ethno medical treatment of asthma and also in epilepsy due to its high serotonin content, which has been implicated in pathophysiology of asthma, this led us to carry out the present study.

Materials and methods

The in vivo studies of histamine induced bronchospasm in guinea pigs and in vitro isolated guinea pig tracheal chain and ileum preparation.

Results

Pre-treatment of guinea pigs with ketotifen (1 mg/kg, p.o.) has significantly delayed the onset of histamine aerosol induced pre-convulsive dyspnea, compared with vehicle control (281.8^a ± 11.7 vs. 112.2 ± 9.8). The administration of methanolic extract (125, 250 and 500 mg/kg, p.o.) did not produced any significant effect on latency to develop histamine induced pre-convulsive dyspnea. On the other hand, methanolic extract of the fruits at the doses employed (i.e., 0.5, 1 and 2 mg/ml) has significantly potentiate the EC₅₀ doses of both histamine and acetylcholine in isolated guinea pig tracheal chain and ileum preparation. In addition, HPLC analysis of the methanolic extract showed the presence of high amounts of serotonin (2.89%, w/w).

Conclusions

On the basis of data, it may be concluded that Ficus religiosa fruits have been found to be ineffective against histamine induced bronchospasm in guinea pigs. In addition, methanolic extract of the fruits have shown to potentiate the bronchoconstriction induced by both histamine and acetylcholine on guinea pig tracheal chain preparation.     

Antidepressant-like activity of the aqueous extract of Allium macrostemon in mice

Aim of the study

The aim of this study was to identify the effects of water extracts of Allium macrostemon Bunge (AM-W), a traditional herb, in mice.

Materials and methods

The antidepressant-like activities of AM-W were evaluated through behavioral despair in forced swimming test and tail suspension test. To elucidate the mode of action of the antidepressant-like effects of AM-W, new born cells in the subgranular zone and the granule cell layer were analyzed by immunostaining for incorporation of 5-bromo-2-deoxyuridine (BrdU). In addition, the effects of AM-W on the expression levels of brain-derived neurotrophic factor (BDNF) were investigated by western blotting and immunohistochemistry.

Results

The administration of AM-W reduced the immobility duration in the forced swimming test and tail suspension test (100 or 200 mg/kg, P < 0.05). Sub-chronic administration of AM-W (100 or 200 mg/kg, p.o., for 14 days) increased the number of BrdU-incorporating cells. The percentage of BrdU-incorporating cells co-localized with NeuN was significantly increased after AM-W administration (100 or 200 mg/kg, P < 0.05). Moreover, the expression levels of BDNF which is reported to be associated with neurogenesis were significantly increased in the hippocampus after administration of AM-W.

Conclusions

These results suggest that AM-W may be a good antidepressant, and that its mechanism of action may be related to its positive effects on neurogenesis and BDNF release.     

An aqueous birch leaf extract of Betula pendula inhibits the growth and cell division of inflammatory lymphocytes

Ethnopharmacological relevance

Leaf extracts of Betula pendula have been traditionally used for the treatment of patients with rheumatoid arthritis (RA) or osteoarthritis.

Aim of the study

We investigated the anti-proliferative capacity of an aqueous leaf extract of Betula pendula (BPE) on human primary lymphocytes in vitro, because activated lymphocytes play a major role in the initiation and maintenance of RA.

Materials and methods

Lymphocyte proliferation and cell division was measured by the activity of mitochondrial dehydrogenases and by using the membrane-permeable dye carboxyfluorescein diacetate succinimidyl ester (CFSE), respectively. Apoptosis was analyzed by surface staining of phosphatidylserine and intracellular activation of effector caspases 3 and 7 in comparison to the drug methotrexate using flow cytometric and photometrical analysis. In addition, the impact of the extract on cell cycle distribution was investigated by propidium iodide staining of DNA. For the bioassays BPE concentrations of 10-160 μg/mL were investigated. A phytochemical analysis, using LC-MS and HPLC, was conducted to identify the polyphenolic constituents of the birch leaf extract.

Results

Leaf extracts of Betula pendula inhibited the growth and cell division (CD8⁺: 40 μg/mL: 45%; 80 μg/mL: 60%; 160 μg/mL: 87%) (CD4⁺: 40 μg/mL: 33%; 80 μg/mL: 54%; 160 μg/mL: 79%) of activated, but not of resting T lymphocytes in a significant dose-dependent manner. The inhibition of lymphocyte proliferation due to apoptosis induction (compared to untreated control: 40 μg/mL: 163%; 80 μg/mL: 240%; 160 μg/mL: 348%) and cell cycle arrest was comparable to that of methotrexate. LC-MS analyses showed that the extract contains different quercetin-glycosides.

Conclusion

Our results give a rational basis for the use of Betula pendula leaf extract for the treatment of immune disorders, like rheumatoid arthritis, by diminishing proliferating inflammatory lymphocytes.     

Effects of tanshinone IIA, a major component of Salvia miltiorrhiza, on platelet aggregation in healthy newborn piglets

Ethnopharmacological relevance

Tanshinone IIA (STS), an active ingredient of the Chinese herb Danshen (Salvia miltiorrhiza) for angina and stroke in adults, has been reported to inhibit platelet function. However, its effect on platelet and underlying mechanism remain largely unknown, particularly in neonates.

Materials and Methods

To investigate the effect of STS on the platelet aggregation and its interaction with various platelet activation pathways, platelet aggregatory function was studied in whole blood stimulated by collagen (2-10 μg/ml) ex vivo in newborn piglets receiving intravenous STS (0.1-10 mg/kg, n = 8) and in vitro in whole blood from newborn piglets (n = 6) incubated with STS (0.1-100 μg/ml). The respective morphological changes of platelets were also examined by scanning electron microscopy. Plasma levels of nitrite/nitrate (NOx) and thromboxane B₂ (TxB₂), matrix metalloproteinase (MMP)-2 and -9 activities were also examined. To further delineate the mechanistic pathway, the effect of STS on endothelial microparticles release from cultured human umbilical vein endothelial cells (HUVECs) was quantified by flow cytometry.

Results

STS impaired the ex vivo, but not in vitro, collagen-stimulated platelet aggregation. Infusion of STS elevated the plasma level of TxB₂ at 10 mg/kg. However, STS had no effect on NOx level. Incubating cultured HUVECs with STS (1 and 10 μg/ml) caused a significant release of endothelial microparticles. Morphologically, STS elicited platelet activation in vivo, but not in vitro.

Conclusions

STS impairs the ex vivo whole blood platelet aggregatory function by activating platelet in vivo in healthy newborn piglets. It implies that STS may elicit its effects by stimulating endothelial microparticles production and eicosanoid metabolism pathway.