Cardiovascular effects of Hyptis fruticosa essential oil in rats

In non-anesthetized normotensive rats, Hyptis fruticosa essential oil (HFEO, 5, 10, 20 and 40 mg/kg; i.v.) induced hypotension associated with tachycardia. In intact and isolated rings of rat superior mesenteric artery (control), HFEO (1-1000 microg/ml, n=6, cumulatively) induced concentration-dependent relaxations of tonus induced by 10 microM phenylephrine (Phe) (pD(2)=2.6+/-0.27; E(max)=64+/-8.3%). In denuded endothelium pre-contracted rings with Phe or K(+)-depolarizing solution (80 mM), the concentration-response curves to HFEO were not shifted (pD(2)=2.3+/-0.25 and 2.3+/-0.28, respectively), but their maximal responses were significantly (P<0.05 vs control) increased (E(max)=122.3+/-18.2% and 92+/-3.6%, respectively). HFEO was also capable of antagonizing the concentration-response curves to CaCl(2) (3 microM-30 mM) in a dose-dependent manner.     

In vitro studies on the selective cytotoxic effect of crocetin and quercetin

Crocetin (5-20 microg/ml), quercetin (10-40 microg/ml), and cisplatin (60-180 microg/ml) used as a positive control drug, were tested against human rhabdomyosarcoma (RD) cells and African green monkey kidney (Vero) cells. The cell viability, morphological changes, and lactate dehydrogenase activity were assessed. RD cell growth was found to be inhibited dose dependently by the three tested compounds. Morphological observation by phase contrast microscopy revealed that both crocetin and quercetin caused intense damage only on the malignant (RD) cells, whereas mild toxic effect was seen with cisplatin also on normal (Vero) cells.     

Antioxidant activity of polyphenols from solid olive residues of c.v. Coratina

The antioxidant profile of extracts from solid olive residue (SOR) of c.v. Coratina, a cultivar widely diffused in the south of Italy, using both cell-free and cell-based experimental models, was investigated. A total hydroalcoholic extract (polyphenols content 19.7%) and a purified extract (Oleaselecttrade mark) (polyphenols content 35.1%) were tested for their ability to quench the stable free radical DPPH, the peroxyl radicals (ORAC assay), by monitoring the loss in fluorescence of R-phycoerythrin induced by the peroxyl radical generator AAPH and their ability to inhibit the cumene hydroperoxide-induced lysis of rat red blood cells (RBC). The total hydroalcoholic extract showed IC(50) 26.96+/-1.53 microg/ml in the DPPH assay, that 10 microg/ml were equivalent to 2.11+/-0.12 microg/ml Trolox (ORAC assay) and IC(50) 1.7+/-0.20 microg/ml in the RBC hemolysis. The Oleaselect extract was 4 to 5 folds more active than the hydroalcoholic extract in all the experimental models, with IC(50) values of 7.36+/-0.38 microg/ml in the DPPH test and of 0.38+/-0.03 microg/ml in RBC; the antioxidant activity in the ORAC assay was slightly greater than that of Trolox (10 microg/ml equivalent to 11.45+/-0.40 microg/ml). The scavenging effect of the extract in the ORAC assay was compared to that of verbascoside (the main polyphenol component) and of caffeic acid (the basic constituent of verbascoside): the results indicate that caffeic acid (10 microg/ml equivalent to 35.70+/-2.95 microg/ml Trolox) is more potent than verbascoside (10 microg/ml equivalent to 15.42+/-1.21 microg/ml Trolox) in entrapping peroxyl radicals. Finally the antioxidant activity of the Oleaselect extract was confirmed in human umbilical endothelial cells (EC) exposed to the site-specific peroxyl radical inducer AAPH, where a massive lipid peroxidation process (marker the fluorescence probe BODIPY) takes place, paralleled by a marked loss of cell viability (calcein assay). The purified extract (1-20 microg/ml) pre-incubated with EC for 1 h dose-dependently inhibited both the lipid-peroxidation damage and cell death. Taking into account the total polyphenol content, these results clearly indicate a greater antioxidant activity for the purified extract, due to a cooperative antioxidant interaction among its polyphenol constituents.     

Pimarane diterpene from Viguiera arenaria (Asteraceae) inhibit rat carotid contraction

ent-Pimara-8(14),15-dien-19-oic acid (PA) isolated from Viguiera arenaria (Asteraceae; Heliantheae) inhibited rat carotid rings contraction induced by phenylephrine (10(-8) mol/l) or potassium chloride (45 mmol/l) at concentration ranging from 5 to 20 microg/ml. This inhibitory effect was not reversible after the removal of this compound from the medium bath.     

Dual inhibition of cyclooxygenase-1 and 5-lipoxygenase by aerial part of Bupleurum fruticescens methanol extract

The effect of the methanol extract from aerial parts of Bupleurum fruticescens on the release of eicosanoids and hydrolytic enzymes was determined on in vitro cell systems. The extract had a significant effect on 5-lipoxygenase (5-LOX) activity, inhibiting both LTB4 and 5(S)-HETE production with IC50 values of 112 microg/ml and 95 microg/ml, respectively. At concentrations of 200 microg/ml, the extract also inhibited cyclooxygenase-1 (90%) and elastase activities (54%). The 12-LOX activity in intact platelets was not affected; a fact, which suggests that phospholipase A2 (PLA2) activity, is not modified by the extract.     

Cytotoxicity and antibacterial activity of extractives from Wedelia calendulacea

The cytotoxicity and antibacterial activity of petroleum ether, chloroform and methanol extracts of Wedelia calendulacea were assayed by brine shrimp lethality bioassay and standardized disk diffusion method against 19 bacterial strains. Three diterpenes isolated from the plant were also evaluated for in vitro antibacterial activities. The LC50 for the crude extracts against the brine shrimp nauplii were found to be 4.59 microg/ml, 7.99 microg/ml and 14.88 microg/ml, respectively, whereas the positive control, vincristine sulfate showed an LC50 of 0.58 microg/ml. Among the crude extracts and pure compounds tested, (-)-kaur-16-en-19-oic acid isolated from the chloroform extract showed the highest inhibitory activity against most of the bacterial strains with mean zone of inhibition of 10-21 mm at 200 microg/disc.     

Effect of meliacine,a plant derived antiviral,on tumor necrosis factor alpha

The effect of meliacine (MAS) and two fractions MAB 1 and MAB 2 obtained from it on the in vitro production of TNF-alpha of murine macrophages induced by bacterial lipopolysaccharide (LPS) (from Escherichia coli) was tested. Simultaneous administration of the above fractions (ranging from 14 to 56 microg/ml) and LPS (10 microg/ml) to a macrophage culture significantly increased the amount of TNF-alpha released at 24 h of induction in a dose-dependent manner. Meliacine alone, at a concentration of 56 microg/ml, is a weak inducer of TNF-alpha production.     

Anti-plasmodial activity of Ailanthus excelsa

The anti-plasmodial activity of Ailanthus excelsa stem bark was investigated. The methanolic extract inhibited in vitro growth of chloroquine-sensitive (D10) and resistant strains (W2) of Plasmodium falciparum (IC50 4.6 and 2.8 microg/ml, respectively). The effect was retained in the chloroform fraction (3.1 and 2.1 microg/ml, respectively). The anti-plasmodial activity could be ascribed to the impairment of haemoglobin degradation through the inhibition of plasmepsin II activity (IC50 of 13.43+/-1.74 microg/ml) and of the haem detoxification to haemozoin.     

树木菌根真菌——美味红菇复合制剂的生物效应*

在探明菌根真菌美味红菇生理活性物质的基础上,为使其实用化,又从该菌的发酵液中提取并研制成真菌复合制剂。除在医学上进行了一系列抗菌活性试验外,同时还在育苗造林上,利用不同树种进行防病保苗促进生长的生物活性试验。本文主要报道应用美味红菇复合制剂对几种亚热带针阔叶树种幼苗和种子进行体内生物活性的试验结果。目的在于观察和研究该复合制剂对促进幼苗生长和提高抗生能力的生物效应,以便进一步开拓美味红菇复合制剂的有效应用范围和途径。     

Amoebicidal and giardicidal compounds from the leaves of Zanthoxylum liebmannianun

The crude ethanol extract from the leaves of Zanthoxylum liebmannianum exhibited inhibitory effect on the reproduction of trophozoites of Entamoeba histolytica (IC(50)=3.48 microg/ml) and Giardia lamblia (IC(50)=58.00 microg/ml). From this extract, asarinin, hyperin, beta-sitosterol, and beta-sitosterol glucoside were isolated. Among them, asarinin was the most active with IC(50) values of 19.86 microg/ml for E. histolytica and 35.45 microg/ml for G. lamblia. The remaining compounds showed moderate activity against both parasites.     

Immunomodulatory effects of the methanolic extract of Epimedium alpinum in vitro

The effect of the methanolic extract of root and rhizome of Epimedium alpinum (MEEA) on phenotype and functions of rat lymphocytes in vitro was studied. It has been found that MEEA at lower concentrations (0.1 microg/ml and 1 microg/ml) significantly enhanced proliferation of splenocytes and thymocytes triggered by concanavalin A (Con A), whereas higher concentrations of the extract (50 microg/ml-500 microg/ml) were inhibitory. The stimulatory effect of MEEA on Con A-induced proliferation of splenocytes correlated with the up-regulation of interleukin-2 receptor alpha (IL-2Ralpha) expression. In addition, increased production of IL-2 was observed when a blocking IL-2Ralpha monoclonal antibody (mAb) was added to cell cultures. MEEA-suppressed proliferation of splenocytes was due to the inhibition of IL-2 production, the down-regulation of IL-2Ralpha expression and the induction of apoptosis. Cellular proliferation in the presence of inhibitory concentrations of MEEA higher than 50 microg/ml could not be restored by the addition of exogenous IL-2.     

Antioxidant and hepatoprotective effect of Acanthus ilicifolius

The alcoholic extract of Acanthus ilicifolius leaves inhibited the formation of oxygen derived free radicals (ODFR) in vitro with IC(50) of 550 microg/ml, 2750 microg/ml, 670 microg/ml and 600 microg/ml (Fe(2+)/ascorbate system), 980 microg/ml (Fe(3+)/ADP/ascorbate system) for superoxide radical production, hydroxyl radical generation, nitric oxide radical formation and lipid peroxide formation, respectively. The oral administration of the extract (250 and 500 mg/kg) significantly reduced CCl(4) induced hepatotoxicity in rats, as judged from the serum and tissue activity of marker enzymes [glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and alkaline phosphatase (ALP)]. These results were comparable with those obtained with curcumin (100 mg/kg, p.o.).     

Screening of Argentinian plants for pesticide activity

Aerial parts of 27 plant species native to Argentina were tested in anti-insect, germination inhibition and bactericide bio-assays. In antifeedant assays on Epilachna paenulata larvae, 11 species showed strong feeding deterrent effects (higher than 90% at 200 microg/cm(2)). Twelve plants strongly inhibited the germination of Avena sativa seeds, but only six inhibited Raphanus sativum germination at 10 mg/ml. Four plants showed complete growth inhibition of Escherichia coli at a concentration of 2 mg/ml.     

A new epicatechin gallate and calpain inhibitory activity from Orostachys japonicus

Calpains are calcium-dependent proteases that cleave a variety of intracellular substrates. The overactivation of mu-calpain is associated with a wide range of disease conditions. To search for calpain inhibitors from natural products, the phytochemical constituents of the ethyl acetate fraction of the whole plant of Orostachys japonicus (Crassulaceae) were studied. The various chromatographic separation of this fraction led to the isolation of a new tannin, (-)-epicatechin 5-gallate (1) along with 9 known compounds. Their structures were elucidated by spectroscopic and chemical analyses. Among them, (-)-epicatechin 5-gallate (1) and kaempferol (9) exhibited moderate inhibitory activity against mu-calpain with IC(50) values of 18.0+/-2.9 and 15.4+/-2.0 microg/ml, respectively.     

The antiplasmodial activity of spermine alkaloids isolated from Albizia gummifera

In the present study the methanolic extract of Albizia gummifera was fractionated into various fractions. These fractions were tested against choroquine sensitive (NF54) and resistant (ENT30) strains of Plasmodium falciparum. All other fractions apart from the alkaloidal fraction showed low activity with IC 50 above 3 microg/ml. The alkaloidal fraction exhibited strong activity against NF54 and ENT30 with IC 50 of 0.16+/-0.05 and 0.99+/-0.06 microg/ml, respectively. Five known spermine alkaloids were isolated from the alkaloidal fraction. These alkaloids exhibited activities against NF54 and ENT30 with IC 50 ranging from 0.09+/-0.02 to 0.91+/-0.10 microg/ml. Four of the alkaloids were further evaluated for in vivo activity against rodent malaria parasite Plasmodium berghei. The alkaloids showed percentage chemosuppression of parasitaemia in mice ranging from 43 to 72%. The use of the extracts A. gummifera for treatment of malaria in traditional medicine seems to have a scientific basis.     

Screening of Indonesian medicinal plants for inhibitor activity on nitric oxide production of RAW264.7 cells and antioxidant activity

Traditional Indonesian medicinal plants were screened for their inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and for the antioxidant activity through the evaluation of free radical scavenging effect and reducing power. The results of screening indicated that 50 methanolic extracts inhibited (>50%) lipopolysaccharides (LPS)-induced NO release from RAW264.7 cells at 50 microg/ml, with 18 having greater than 100% inhibition. At 200 microg/ml, 61 methanol extracts exhibited inhibitory activity (>50%), with 45 showing greater than 100% inhibition. In addition, the free radical scavenging effects of 6 methanolic extracts were found to be more than 50% for extract concentration of 0.5 mug/ml. The results indicate that the extracts contain active compounds that inhibit NO release and scavenge free radical.     

Antioxidant activity of isocytisoside and extracts of Aquilegia vulgaris

Two extracts (ethyl acetate and ethanol) and isocytisoside obtained from Aquilegia vulgaris were tested for their antioxidant and free radical scavenging activity in vitro. Inhibition both non-enzymatic (IC50: 150-219 microg/ml) and enzymatic (IC50: 23-60 microg/ml) microsomal lipid peroxidation was observed, the extracts being more active than isocytisoside. The substances tested appeared to be weak hydroxyl radical scavengers, showed very low TEAC values and moderate iron chelation ability. However, all preparations at the concentration 25 microg/ml inhibited superoxide anion formation at the range 47-68%. Despite of the lack of a potent free radical scavenging ability the substances tested demonstrated significant antioxidant activity. Relationship between this parameter and the content of phenolic groups was noticed.     

Antibacterial and allelopathic activity of extract from Castanea sativa leaves

Following the extraction of Castanea sativa with an aqueous solution of sulfuric acid (pH 3.0), the ethyl acetate soluble fraction was tested for its antibacterial and allelopathic activity. The extract was shown to have pronounced antibacterial effects against seven of the eight strains of Gram-positive and Gram-negative bacteria used (MIC in the range of 64-256 microg/ml and MBC in the range of 256-512 microg/ml). The active fraction was analyzed by TLC and HPLC showing the presence of rutin, hesperidin, quercetin, apigenin, morin, naringin, galangin and kaempferol. Standards of the identified flavonoids were tested against the same bacterial strains. The highest activity was shown by quercetin, rutin and apigenin. The allelopathic effect was tested against Raphanus sativus seed germination. The extract, quercetin, rutin and apigenin caused a decrease in the percentage of seed germination and root and epicotyl growth.     

Morinda lucida extract induces endothelium-dependent and -independent relaxation of rat aorta

The effect of an aqueous extract of Morinda lucida (ML) on vascular tone was tested using rat aortic rings precontracted with noradrenaline (10(-7) mol/l). Relaxation responses were determined with endothelium-intact, L-NAME-treated, methylene blue-treated and endothelium-denuded tissues. In the concentration range of 0.25-9.0 mg/ml, ML elicited vasorelaxation in noradrenaline-precontracted rings. This relaxation response was partially attenuated by removal of the endothelium, and completely inhibited by pretreatment of rings with L-NAME and methylene blue. Thus, ML-induced relaxation of vascular smooth muscle occurs via endothelium-dependent and -independent mechanisms, the former of which involves the nitric oxide-cGMP pathway.     

Pro-cognitive activity induced in the rat by low doses of R-(+)-hyoscyamine

In the passive-avoidance test R-(+)-hyoscyamine (10-100 microg kg(-1) i.p.) prevented amnesia induced by antimuscarinic treatment with AF-64A and benzhexol. The antiamnesic effect of R-(+)-hyoscyamine was comparable to that exerted by the cholinesterase inhibitor physostigmine (0.2 mg kg(-1) i.p) and the M(1) selective agonist AF-102B (10 mg kg(-1) i.p.). In the social learning test, R-(+)-hyoscyamine (10-100 microg kg(-1) i.p.) in adults rats, reduced the duration of active exploration of the familiar partner in the second session of the test similar to the nootropic drug piracetam (30 mg kg(-1) i.p.). These results demonstrated the ability of R-(+)-hyoscyamine to modulate memory functions and suggest that R-(+)-hyoscyamine could be useful in the treatment of cognitive deficits.