Cistus incanus and Cistus monspeliensis inhibit the contractile response in isolated rat smooth muscle

The lyophilized aqueous extracts from Cistus incanus L. (CI) and Cistus monspeliensis L. (CM) collected in Sicily were studied in order to evaluate their myorelaxant activity by using isolated smooth muscle of rat ileum and rat aorta. Both CI and CM extracts concentration-dependently inhibited the contractile response to acetylcholine (ACh), phenylephrine (PE) and to 100 mM KCl. The concentration-contraction curves to ACh in ileum and to PE in aorta, were displaced to the right by Cistus extracts in a non-competitive manner, with a depression of the maximum contractile response. The EC50 (microg/ml) of CM and CI were: ileum/KCl, CM 457+/-99, CI 681+/-80; ileum/ACh 100 microM, CM 297+/-66, CI 335+/-41; aorta/KCl, CM 360+/-21, CI 843+/-36; and aorta/PE 10 microM, CM 287+/-33, CI 451+/-58. The two extracts resulted almost equi-active in ileum, whereas CM was more active than CI in aorta. These data indicate that Cistus extracts act as spasmolytic on intestinal and vascular smooth muscle. The antagonism they exert on ACh-, PE- and KCl-evoked contractions seems to be functional, because it is not specifically directed toward any particular receptor; furthermore, a calcium-antagonist activity seems unlikely, since the extracts are capable of completely block the contractile response to agonists.     

Inhibitory effects of the sesquiterpene T-cadinol on contractile responses in the isolated guinea-pig ileum

The smooth muscle relaxing effect of the sesquiterpene T-cadinol, isolated from scented myrrh (resin of Commiphora guidottii Chiov., Burseraceae), was investigated. The compound inhibited the contractile responses in the isolated guinea-pig ileum to histamine, carbachol, Ba²⁺ and K⁺ in a concentration dependent and reversible manner. The antagonism of the receptor-mediated contractions induced by histamine and carbachol was not of a competitive type. The contractions induced by Ba²⁺- and K⁺ were somewhat more sensitive to the action of T-cadinol than the receptor mediated contractions. It is suggested that the compound may interfere with a step of the contraction sequence common to all four spasmogens.     

Effects of extract of Cistus populifolius L. on the central nervous system.

We report the effects on the central nervous system (CNS) and on analgesic activity of an aqueous extract of Cistus populifolius L. The extract was assayed for effects on spontaneous locomotor activity, methylphenidate-induced hypermotility, motor coordination, exploratory behaviour, rectal temperature and sodium pentobarbital-induced hypnosis. Analgesic activity was evaluated using the hot plate test. The C. populifolius extract at dosages of 286 and 430 mg/kg caused very significant reductions in spontaneous locomotor activity, hypermotility, motor coordination, exploratory behaviour and rectal temperature, and a slight increase of sleeping time was noted in the sodium pentobarbital-induced sleep test. The extract exhibited central analgesic affects in the hot plate test.     

Vasodilator Effects of the Extract of the Leaves of Cistus populifolius on Rat Thoracic Aorta

The effects of different extracts of Cistus populifolius L. on smooth muscle were studied. The aqueous extract inhibited in a dose dependent manner the noradrenaline (NA) (10⁻⁹–1.03×10⁻⁶ MSC ) and CaCl₂ (2×10⁻⁴–1.28×10⁻² MSC )-induced contractions in rat thoracic aorta. Furthermore, this extract induced relaxant effects in rat aorta precontracted with NA (10⁻⁶ MSC ) and with K⁺ (80 mMSC ). Two different vasodilator responses were observed on NA-induced contractions: one an endothelium-dependent response abolished by methylene blue but not by indomethacin, and the other an endothelium-independent response unaffected by methylene blue and indomethacin similar to that obtained with a flavone, luteolin (10⁻⁵ MSC ). The search for active constituents included a bioactivity-directed fractionation of the lyophilized aqueous extract (LAE) using vascular reactivity experiments. Four different fractions (Cl₂CH₂, Me₂CO, MeOH, H₂O) were analysed at two different concentrations (1 and 2 mg (dry plant)/mL). The methanol fraction was the most active on NA precontracted vascular segments with endothelium, whereas the water fraction was the most active on segments without endothelium. These relaxant effects were less on K⁺ (80 mMSC )-induced contractions. Due to these results we suggest that this plant contains interesting hydrophilic compounds with strong pharmacological action. The endothelium-independent relaxant effect is probably related to flavonoid constituents. However we cannot relate the endothelium-dependent relaxation to known natural compounds in Cistus species. The presence of these constituents with relaxing properties on smooth muscle could account for the use of Cistus plant in traditional medicine.     

Inhibitory effects of Okbyungpoong-Gamhmi on anaphylactic responses

We investigated the effect of a herbal formulation Okbyungpoong-Gamhmi (OG) on mast cell-dependent anaphylactic reactions by intra-rectal administration. OG concentration dependently inhibited compound 48/80-induced anaphylaxis-like response and ear swelling response with doses of 0.01-1g/kg. OG also inhibited the passive cutaneous anaphylaxis at the same concentrations. The histamine release induced by compound 48/80 or IgE from the rat peritoneal mast cells was reduced by 64.2 and 63.6%, respectively, at 1g/l. These results provide evidence that intra-rectal therapy of OG may be beneficial in the treatment of anaphylactic response.     

Anti-spasmodic effects of Zizyphus lotus (L.) Desf. extracts on isolated rat duodenum

Aim of the study

The present study deals with the anti-spasmodic activity of the aqueous and the methanolic extracts of the leaves and the root barks of Zizyphus lotus (L.) Desf. on male rats.

Materials and methods

This activity was assessed on contractions of isolated rat duodenum, induced by acetylcholine, KCl, and BaCl₂ and compared with the effect of atropine and papaverine.

Results

Both extracts of leaves and root barks caused significant relaxation of spontaneous contractions and produced a concentration-dependent inhibition (P < 0.01–0.001) of contraction induced by spasmogenic agents.

Conclusion

These results indicate that Zizyphus lotus extracts contain anti-spasmodic constituents mediating their effect through cholinergic receptors and blockade Ca²⁺ influx. This could explain the traditional use of Zizyphus lotus in the treatment of the intestinal diseases.     

Effects of Thymus species extracts on rat duodenum isolated smooth muscle contraction

The diethylether, ethylacetate and butanolic extracts from Thymus webbianus and Thymus leptophyllus were tested for spasmolytic activity. Pre-incubation of the isolated rat duodenum with these extracts for 10 min produced a concentration-dependent inhibition of acetylcholine-induced contractions. This effect was at least ten times greater with the apolar extracts than with the polar extracts.     

Pharmacological effects of Agapanthus africanus on the isolated rat uterus.

The Agapanthus africanus plant is used by South African traditional healers as a phytomedicine in herbal remedies to treat pregnancy-related ailments and to augment labour. It has already been shown that an aqueous extract of A. africanus causes smooth muscle contractions in the isolated uterus and ileum preparations. In the present study, the effects of an aqueous extract of A. africanus leaves was examined on receptor systems involved in contraction of the uterine smooth muscle in order to determine the mechanism of its pharmacological effect relevant to its ethnic use to augment labour. The extract was tested on the isolated rat uterus preparation. The aqueous extract of A. africanus leaves was found to exhibit agonist activity on uterine muscarinic receptors and to promote the synthesis of prostaglandins in the oestrogenized rat uterus. Some pharmacological justification for the ethnic use of A. africanus as a herbal oxytocic in prolonged labour has been provided.     

Pharmacologic effects of mansonine on arrhythmias induced in isolated rat heart

The effect of 3 x 10(-13) M Mansonine (MSN) was observed on arrythmias induced on isolated rat heart, perfused with either hypopotassic solution, atropine solution, or MacEwen physiological saline at 18 degrees C. Generally the reversal of induced arrythmias was complete with the hypopotassic solution, and partial with the MacEwen solution at 18 degrees C. On the other hand, when atropine and MSN were combined, their effects induced heart arrest, probably due to an intracellular calcium accumulation. In this case, the heart recovery occurred by preventing the calcium influx, either through EDTA chelation, or blockade of calcium channels. It was concluded that MSN probably acts like most cardiac glycosides, by blocking the Na(+)-K+ ATPase. This may activate a calcium influx, which causes the subsequent positive inotropic effect, as well as a negative chronotropic effect due to an increase of the membrane activation set point.     

Inhibitory effects of various flavonoids isolated from leaves of persimmon on angiotensin-converting enzyme activity

The leaves of the persimmon Diospyros kaki, have been traditionally used for treatment of hypertensive diseases in Japan. We have studied the inhibitory effects of four flavonoids isolated from the leaves of the persimmon on angiotensin-converting enzyme activity. The four flavonoids astragalin [1], kaempferol-3-O-(2"-O-galloyl)-glucoside [2], isoquercitrin [3], and quercetin-3-O-(2"-O-galloyl)-glucoside [4] inhibited the angiotensin-converting enzyme activity in a dose-dependent fashion. Compounds 1-4 produced 67%, 53%, 33%, and 48% inhibition at a concentration of 300 micrograms/ml, respectively. The 50% inhibitory concentrations (IC50) of 1 and 2 for the angiotensin-converting enzyme were 180 micrograms/ml and 280 micrograms/ml, respectively. On the other hand, 2 and 4 were shown to have tannin activities, but 1 and 3 had no tannin activities. These results suggest that there is no relationship between the inhibition for angiotensin converting enzyme activity and the tannin activity for the four flavonoids.     

Parthenolide inhibits the contractile responses of rat stomach fundus to fenfluramine and dextroamphetamine but not serotonin

The isolated rat stomach fundus preparation, a sensitive bioassay to evaluate serotonin-(5-HT) like activity, was used as a model to study the effects of parthenolide (PAR), a component of Tanacetum parthenium (feverfew), on 5-HT storage, release and stimulation of the 5-HT_2B receptor. Cumulative-concentration response curves to 5-HT and the indirect-acting serotonergics fenfluramine (F) and dextroamphetamine (DA) on fundus were obtained in the presence and absence of 1 × 10⁻⁶ to 1 × 10⁻⁵ PAR. 5-HT release elicited by F and DA was indirectly assessed by comparing the contraction elicited by these compounds on tissues from reserpine-treated, l-p-chlorophenylalanine (1-PCPA)-treated and untreated rats. The observed order of agonist potencies on intact fundus was: 5-HT > DA > F and the order of intrinsic activity was: 5-HT > DA > F. PAR did not show agonist effects nor antagonism toward 5-HT on rat fundus at all concentrations used. However, PAR antagonized non-competitively the effects of F and DA. Contractile responses to 5-HT were not significantly different on mucosa-denuded fundus and tissue strips from untreated, 1-PCPA- and reserpine-treated rats. PAR appears to inhibit 5-HT release mediated responses by the indirect-acting 5-HT agonists on fundal tissue.     

Terminalia arjuna,an ayurvedic cardiotonic,increases contractile force of rat isolated atria

The direct effects of aqueous, ethanolic, chloroform and petroleum ether extracts of Terminalia arjuna (family: Combretaceae) bark, an ayurvedic remedy for cardiovascular disorders, were studied on isolated atria of rats. The aqueous extract produced a substantial positive inotropic effect (EC₅₀ = 0.25 mg/mL) but no change in the rate. The ethanol, chloroform and petroleum ether extracts all decreased the rate of contraction. A slight increase in force was seen with ethanol and chloroform extracts. Higher concentrations of the chloroform extract had a negative inotropic effect. The ethanol extract decreased the maximum following frequency of the left atria. It is concluded that Terminalia arjuna has a significant positive inotropic property on rat atria in vitro which could contribute to its efficacy in treating cardiovascular disorders.     

Inhibitory effects of triterpenes isolated from Hoelen on free radical-induced lysis of red blood cells

Hoelen, sclederma of Poria cocos Wolf, has long been used as a sedative and diuretic in traditional medicine. Formerly, we demonstrated that Hoelen in vitro protects red blood cells from AAPH-induced hemolysis. In this study, tests were carried out to identify the main ingredient of Hoelen that has the scavenging effect on free-radicals. Triterpene carboxylic acids isolated from the methanol extract of Hoelen, i.e. pachymic acid, polyporenic acid, 3-epidehydrotumulosic acid, 3beta-hydroxylanosta-7,9(11), 24-trien-21-oic acid and 3-o-acetyl-16 alpha -hydroxytrametenolic acid, were found to have inhibitory activities against AAPH-induced lysis of red blood cells.     

柴胡皂苷d-黄芩苷配伍对CCl_4诱导大鼠HSC的TLR4-NF-κB通路作用研究

目的:探讨柴胡皂苷d-黄芩苷(SaikosaponinD-Baicalin,SB)对CCl4诱导肝星状细胞(Hepatic stellate cell,HSC)的作用机制。方法:HSC分空白对照(无药物处理),CCl4诱导(6mmol/L CCl_4作用6h),给药(6mmol/L CCl4作用6h后,2.5、5、10ug/ml的SB作用24h),TAK-242、BYA 11-7082组(6mmol/L CCl_4作用6h后,TAK-242 10mol/L、BYA 11-7082 2mol/L作用24h)。ELISA法检测透明质酸酶(Hyaluronidase,HA)、层粘连蛋白(Laminin,LN)、III型前胶原(ProcollagenⅢ,PCIII)、IV型胶原(Collagen Type IV,IV-C)浓度,RT-PCR、Western blot方法检测细胞中Toll样受体4(Toll-like receptors4,TLR4)、核转录因子(NF-κB)基因、蛋白的表达。结果:与CCl4干预组比较,SB、TAK-242、BYA 11-7082可降低CCl4造成的HSC细胞增殖,HA、LN、PCIII、HA细胞释放水平及NF-κB基因、蛋白的表达。SB、TAK-242可下调TLR4基因、蛋白表达。结论:SB可以抑制CCl4诱导的炎症因子基因、蛋白表达,改善肝纤维化相关指标,其作用机制可能与TLR4-NF-κB转录活性及蛋白活性相关。     

Inhibitory effects of Ganoderma applanatum on rat lens aldose reductase and sorbitol accumulation in streptozotocin-induced diabetic rat tissues

Aldose reductase, the key enzyme of the polyol pathway, is known to play important roles in diabetic complications. Therefore, inhibitors of aldose reductase would be potential agents for the prevention of diabetic complications. To evaluate the inhibitory potential of aldose reductase from Ganoderma applanatum (Polyporaceae), methanol (MeOH) and water extracts were tested for their effects on rat lens aldose reductase (RLAR). The effects of both extracts on streptozotocin (STZ)-induced diabetes in rats were also investigated. The MeOH extract exhibited a potent rat lens aldose reductase (RLAR) inhibition in vitro, and showed a significant inhibition, of not only serum glucose concentrations, but also of sorbitol accumulations in the lens, red blood cells (RBC) and sciatic nerves in STZ-induced diabetic rats. Associated with a reduction in serum glucose concentration in STZ-induced diabetic rats, this extract was found to cause a significant glucose tolerance effect. These results suggested that G. applanatum might possess constituents with antidiabetic and inhibitory effects on diabetic complications.     

Inhibitory effects of fungi on aggregation of rabbit platelets and rat polymorphonuclear leucocytes in vitro

Fungi of six families, encompassing 28 species, have been screened for their inhibitory effects on adenosine-5'-diphosphate (ADP), acetyl-glyceryl-phosphorylcholine (PAF) or collagen-induced rabbit platelet aggregation. Some fungi have also been studied for their ability to inhibit neutrophil aggregation induced by calcium ionophore A 23187. The results suggest that fungi may be a potential source of inhibitors of platelet and neutrophil aggregation.     

Relaxant effects of Artemisia ludoviciana on isolated rat smooth muscle tissues

Ethnopharmacological relevance

Artemisia ludoviciana spp. mexicana (Willd. Ex.) Spring D.D. Keck (Asteraceae), known as “estafiate” is employed for the treatment of diarrhea, dysentery, parasites, abdominal pain, vomiting, stomach ache, and also as antispasmodic agent. The aim of the present study was to evaluate the relaxant effect of hexanic (HEAl), dichloromethanic (DEAl) and methanolic (MEAl) extracts on isolated trachea, ileum and aorta rat rings, and to establish the tracheo-relaxant mode of action of DEAl.

Materials and methods

All extracts were investigated based on their capacity of to inhibit the rat ileum spontaneous contraction, to relax contraction induced by noradrenaline (0.1 μM) on endothelium-intact and endothelium-denuded thoracic aorta rat rings, and also to inhibit contraction provoked by carbachol (1 μM) on rat trachea.

Results

Organic extracts had no spasmolytic action on ileum strips compared to positive control (papaverine, p < 0.05). On the other hand, all extracts induced a significant concentration- and partial endothelium-dependent vasorelaxant activity. Extracts also showed significant relaxant effect on pre-contracted tracheal tissue in a concentration-dependent manner. In last two experiments, DEAl was the most potent and efficient extract; however, it was less potent than papaverine and theophylline, used as positive controls (p < 0.05). In tracheal preparation, DEAl shifted to the right, in a parallel manner, the concentration-response curves induced by carbachol (p < 0.05). Also, DEAl induced a significant relaxant effect on the contraction produced by potassium chloride (KCl, 80 mM). Pre-incubation with 1-H-[1,2,4]-oxadiazolo-[4,3a]-quinoxalin-1-one (ODQ, 10 μM), indomethacin (10 μM), N_ω-nitro-l-arginine methyl ester (l-NAME, 10 μM), glibenclamide (10 μM) and 2-aminopyridine (2-AP, 100 μM) did not modify the DEAl-relaxant curves.

Conclusions

Functional experiments suggest that the most active extract, DEAl, induced its relaxant effect by possible muscarinic receptors antagonism and calcium channel blockade in tracheal rings. On the other hand, significant vasorelaxant activity showed by DEAl is partially endothelium-dependent. Finally, spasmolytic activity induced by the extracts in the rat ileum was not significant, which suggests that the antidiarrheic effect of the plant is related to antimicrobial and antiparasitic properties previously described.     

Uterotonic effects of hydromethanolic extract of Parquetina nigrescens (Periplocaceae) on spontaneous contractile activity in the isolated myometrium of pregnant rats

Parquetina nigrescens (Afz.) Bullock (Periplocaceae) hydromethanolic extract (PAR) in reference solution exerts a stimulating and spasmogenic action on the pregnant rat myometrium in vitro. This action is characterised by increasing amplitude of spontaneous isometric contractions and a slight elevation of muscular basic tonus. These effects on myometrium may be compared with those provoked by sulprostone (PGE₂) in the same experimental conditions. In calcium free solution, Parquetina nigrescens extract could restore partially spontaneous contractile activity. On the contrary, in presence of EDTA PAR induces a complete abolition of the activity. On the other hand, in calcium free solution, sulprostone is able to develop a clear elevation of basic tonus (contracture). These observations support the hypothesis that the extract has an oxytocin-like effect, which is characterised by an extracellular influx of calcium, responsible for the increase of the maximum isometric contraction amplitude. Sulprostone activates both extracellular and intracellular calcium responsible for the increase of contractile activity and development of the contracture of uterine smooth muscle.