In vivo and in vitro activities of the seed extract of Piper guineense Schum. and Thonn. against skin and gill monogenean parasites of gold fish (Carassius auratus auratus)

Methanol extracts of the seeds of Piper guineense (Piperaceae) were active against gold fish (Carassius auratus auratus L. Pisces Cyprinidae) monogenean parasites. The seed extract of P. guineense was administered at different concentrations (0.5-2.0 mg/L) under in vivo and in vitro conditions. There was a higher efficacy of the effects of the extracts against fish parasites under in vitro situations than under in vivo. Three major compounds (piperanine, N-isobutyl (E,E)-2,4 decadienamide and Deltaalpha,beta-dihydrowasanine) were identified from the seed extract of Piper guineense by LC-MS analysis.     

Uterine muscle reactivity to repeated administration and phytochemistry of the leaf and seed extracts of Piper guineense

The leaf and seed of Piper guineense were separately extracted and the effects of repeated treatments on rat uterine contractions and their chemical composition were investigated. Repeated treatments with the extracts enhanced spontaneous uterine muscle contractions in a dose related pattern for up to 14 days which was followed by a marked decrease in uterine response in those treated for 30 days. Similarly, the pretreatment with the extracts maximally enhanced oxytocin induced uterine contraction in those rats treated for 3 days, this was followed by a gradual reversal of the effect when treatment was repeated for up to 14 days. This enhanced uterine contraction was inhibited following treatment for 30 days. In a further study, treatment with the extracts induced a significant increase in the uterine weight similar to that seen with oestradiol. It is therefore concluded that the leaf and seed extracts of Piper guineense possess oestrogenic and oxytocic properties which might justify their usage in Nigerian traditional medicine.     

Effects of stembark and leaf extracts of Bridelia ferruginea on skeletal muscle

The ethanolic extracts of the leaves and stembark of Bridelia ferruginea were separately investigated for their effects on skeletal muscle using the phrenic nerve-hemidiaphragm muscle preparation from rats. The bark extract inhibited twitch tension induced by direct electrical stimulation (muscle) (MS) but not indirect electrical stimulation (nerve) (NS) of the diaphragm. It inhibited tetanus tension to both nerve (TNS) and muscle stimulation (TMS), had no effect on K⁺-induced contracture and reduced the minimal fusion frequency (MFF). The leaf extract had no effect on twitch tension to NS and MS or K⁺-induced contracture but increased tetanus tension to TNS or TMS as well as MFF. These findings suggest that the bark extract does not affect influx of extracellular Ca²⁺ but inhibits the intracellular mobilization of Ca²⁺. The leaf extract also had no effect on influx of extracellular Ca²⁺ but most likely facilitated the intracellular mobilization of Ca²⁺. Thus, the intracellular action of the bark extract is opposite to that of the leaf extract.     

Effect of Extract of Leaf and Seed of Piper guineense on Some Smooth Muscle Activity in Rat,Guinea-pig and Rabbit

Extracts of the leaf and seed of Piper guineense were separately prepared and their pharmacological effects screened using smooth muscle of the gastrointestinal tract and uterus. The leaf extract enhanced both the frequency and tone of spontaneous contractions of rabbit jejunum and induced contraction of guinea-pig ileum, which were blocked by atropine. The seed extract had the opposite effect on rabbit jejunum, an inhibition which was antagonized by prazocin, and little or no effect on guinea-pig ileum. Both extracts had a stimulant effect on rat uterine muscle, the seed extract to a lesser extent.     

Comparison of the skeletal muscle relaxant properties of Portulaca oleracea extracts with dantrolene sodium and methoxyverapamil

The effects of aqueous (AEE), dialysable (DIF) and methanol (MEE) extracts of Portulaca oleracea stems and leaves were compared with those of dantrolene sodium and methoxyverapamil (D-600) with respect to inhibition of twitch tension on the rat phrenic nerve-hemidiaphragm and with respect to contracture induced by nicotinic agonists on the frog rectus abdominis preparations. The extracts, dantrolene and D-600 inhibited twitch tension due to indirect electrical stimulation via the phrenic nerve (NS) on hemidiaphragm muscle, whereas the extracts and dantrolene inhibited, in addition, twitch amplitude due to direct muscle stimulation (MS). The extracts, dantrolene and D-600 also attenuated K+- and caffeine-induced contractures with the extracts and D-600 also reducing the time taken for the K+-induced contracture to fall to basal tension. In addition, the tetanic tension due to NS and MS was attenuated with only the extracts and dantrolene reducing the twitch/tetanus ratio (MS). There was a non-significant but consistent tendency for mutual potentiation between the extracts and dantrolene with respect to their inhibitory effect on twitch amplitude (MS) resulting in a shift to the left of the concentration-response curves to the extracts or dantrolene. This was not evident with the extracts and D-600 or dantrolene and D-600. Simultaneous addition of the extracts and dantrolene resulted in an increase in the rate of twitch tension inhibition and a decrease in the time to maximum relaxation of twitch amplitude (MS). The extracts and D-600 proved more effective in attenuating nicotinic agonist (acetylcholine, carbachol and nicotine)-induced contractures on the rectus abdominis muscle than dantrolene. From these observations, it appears that the Portulaca oleracea extracts mimic, in part, the effect of D-600 and dantrolene on the rat hemidiaphragm and frog rectus abdominis muscles; therefore, the muscle relaxant properties of the extracts may be due, in part, to inhibition of trans-membrane Ca influx, interference with the Ca-induced Ca release process and/or inhibition of the release of intracellular Ca from stores in the sarcoplasmic reticulum.     

Mechanism-based inhibition of CYP3A4 and CYP2D6 by Indonesian medicinal plants

Thirty samples of Indonesian medicinal plants were tested for their mechanism-based inhibition on cytochrome P450 3A4 (CYP3A4) and CYP2D6 via erythromycin N-demethylation and dextromethorphan O-demethylation activities in human liver microsomes. From screening with 0 and 20min preincubation at 0.5mg/ml of methanol extracts, five plants (Cinnamomum burmani bark, Foeniculum vulgare seed, Strychnos ligustrina wood, Tinospora crispa stem, and Zingiber cassumunar rhizome) showed more than 30% increase of CYP3A4 inhibition, while three (Alpinia galanga rhizome, Melaleuca leucadendron leaf, and Piper nigrum fruit) showed more than 30% increase of CYP2D6 inhibition. In these eight plants, Foeniculum vulgare seed, Cinnamomum burmani bark, and Strychnos ligustrina wood showed time-dependent inhibition on CYP3A4 and Piper nigrum fruit and Melaleuca leucadendron leaf on CYP2D6. Among these, four plants other than Melaleuca leucadendron revealed NADPH-dependent inhibition. Thus, Foeniculum vulgare, Cinnamomum burmani, and Strychnos ligustrina should contain mechanism-based inhibitors on CYP3A4 and Piper nigrum contain that on CYP2D6.     

Essential oil composition of Piper guineense and its antimicrobial activity. Another chemotype from Nigeria

The analysis of the essential oil of Piper guineense from Nigeria presents a new chemotype of constituents different from earlier reports with the absence of the usual myristicin. Ishwarane, a common constituent of Aristolochia indica and Bixa orellana, was also isolated from the essential oil of the fruit. The essential oil inhibited the growth of Pseudomonas aeruginosa UCH 655 strain at 5 mg/mL on which standard antibiotic drugs were ineffective.     

Effects of extracts of Portulaca oleracea on skeletal muscle in vitro

Extracts of Portulaca oleracea inhibited twitch tension due to direct (MS) and indirect electrical stimulation via the phrenic nerve (NS) of the rat hemidiaphragm muscle. The rank order of potency was dialysable extract greater than or equal to methanol extract greater than diethylether extract, although all exhibited equal efficacy. The non-dialysable extract did not inhibit twitch tension due to MS or NS. The dialysable, methanol and diethylether extracts inhibited tetanus tension, and attenuated the area under the K+- and caffeine-induced contracture. The contracture induced by nicotinic agonists and K+ on the rectus abdominis muscle was significantly inhibited by these extracts.     

The effects of extracts from anti-diarrheic Thai medicinal plants on the in vitro growth of the intestinal protozoa parasite: Blastocystis hominis

The activities of n-hexane, dichloromethane and methanol extracts from five anti-diarrheic Thai medicinal plants, Acacia catechu (Fabaceae) resin, Amaranthus spinosus (Amaranthaceae) whole plant, Brucea javanica (Simaroubaceae) seed, Piper longum (Piperaceae) fruit and Quercus infectoria (Fagaceae) nut gall were tested against the in vitro growth of fresh isolates of the intestinal protozoan parasite, Blastocystis hominis. The extracts at concentrations that ranged from 62.5 to 2000 microg/mL, were incubated with several isolates of Blastocystis hominis for 48 h. The activities were classified as killed, inhibited, moderately inhibited and not-inhibited. Dichloromethane and methanol extracts from the Brucea javanica seed and a methanol extract from Quercus infectoria nut gall showed the highest activity. At a concentration of 2000 microg/mL, the three extracts killed 82, 75 and 67% of the Blastocystis hominis samples tested and inhibited 94, 100 and 76% of them, respectively. Metronidazole, used as a reference antiprotozoan drug, at a concentration of 40 microg/mL, killed 97% of the Blastocystis hominis isolates and inhibited all samples tested at concentrations that ranged from 1.25 to 20 microg/mL.     

Butea superba Roxb. enhances penile erection in rats

This study aimed to investigate the effects of ethanol extracts of Butea superba in increasing intracavernous pressure (ICP) in vivo. The extracts were prepared from fresh and dried root cores and fresh and dried root barks. Penile erection was induced in aged rats by electrical stimulation of the cavernous nerve. Cavernous smooth muscle relaxation was also observed in vitro in the presence of the extract, cGMP or isobutyl-methylxanthine (IBMX) alone or the extract together with cGMP or IBMX. The dried root core extract from Phrae was the most effective in increasing the ICP. The dose-response relationship study revealed a bell-shape curve with the maximum effective dose at 1 mg/kg. The ICP of the control and 1 mg/kg extract-treated animals were 45.3 +/- 2.5 and 100.9 +/- 14.0 mmHg, respectively. The extract, cGMP and IBMX alone induced dose dependent muscle relaxation. B. superba significantly enhanced the effects of cGMP and IBMX. The results suggest that ethanol extracts of B. superba are effective in enhancing penile erection. The dried root core extract from Phrae is the most effective part with a maximal dose of 1 mg/kg. The results also suggest that B. superba may act through cAMP/cGMP pathways.     

Pharmacological effects of Eugenia punicifolia (Myrtaceae) in cholinergic nicotinic neurotransmission

The effects of the aqueous crude extract (5%) of Eugenia punicifolia on cholinergic nicotinic neurotransmission were investigated. Actions of aqueous crude extract over the inhibitory effect of the cholinergic nicotinic antagonists gallamine or pancuronium, on contractions induced by electrical stimulation of phrenic nerve of rat diaphragm, were studied. Tissues were mounted as for isotonic contractions and stimulation was delivered at submaximal voltage. Addition of Eugenia punicifolia did not alter the amplitude of twitch contraction. Gallamine (IC(50): 28.8+/-0.51 microM) or pancuronium (IC(50): 3.16+/-0.11 microM) completely inhibited twitch contractions. After the maximum effect of the antagonists was achieved, addition of the aqueous crude extract (0.5-1.0 mL) totally recovered the responses to electrical stimulation. Neostigmine, a reversible acethylcholinesterase inhibitor, partially recovered responses (49.70+/-6.90% at 1 microM). In another series of experiments, previous incubation of the extract (0.5 mL) shifted to the right inhibitory concentration-response curves for the antagonists gallamine (IC(50) before E. punicifolia: 35.8+/-1.61 microM; IC(50), after E. punicifolia: 2.24+/-0.04 mM) and pancuronium (IC(50), before E. punicifolia: 3.55+/-0.13 microM; IC(50), after E. punicifolia: 0.39+/-0.01 mM). Our results show that the aqueous extract of E. punicifolia recovered the action of competitive nicotinic antagonists at the neuromuscular junction. A receptor-mediated mechanism or the possibilities of interactions of the extract with the enzyme acethylcholinesterase, however, remain to be investigated.     

In vitro susceptibility of Helicobacter pylori to botanical extracts used traditionally for the treatment of gastrointestinal disorders

The gram-negative bacterium Helicobacter pylori (HP), identified in 1982, is now recognized as the primary etiological factor associated with the development of gastritis and peptic ulcer disease. In addition, HP infections are also associated with chronic gastritis, gastric carcinoma and primary gastric B-cell lymphoma. For centuries, herbals have been used in traditional medicine to treat a wide range of ailments, including gastrointestinal (GI) disorders such as dyspepsia, gastritis and peptic ulcer disease (PUD). However, the mechanism of action by which these botanicals exert their therapeutic effects has not been completely elucidated. As part of an ongoing screening program, the study assessed the in vitro susceptibility of 15 HP strains to botanical extracts, which have a history of traditional use in the treatment of GI disorders. Methanol extracts of Myristica fragrans (seed) had a MIC of 12.5 microg/mL; Zingiber officinale (ginger rhizome/root) and Rosmarinus officinalis (rosemary leaf) had an MIC of 25 microg/mL. Methanol extracts of botanicals with a MIC of 50 microg/mL included Achillea millefolium, Foeniculum vulgare (seed), Passiflora incarnata (herb), Origanum majorana (herb) and a (1:1) combination of Curcuma longa (root) and ginger rhizome. Botanical extracts with a MIC of 100 microg/mL included Carum carvi (seed), Elettaria cardamomum (seed), Gentiana lutea (roots), Juniper communis (berry), Lavandula angustifolia (flowers), Melissa officinalis (leaves), Mentha piperita (leaves) and Pimpinella anisum (seed). Methanol extracts of Matricaria recutita (flowers) and Ginkgo biloba (leaves) had a MIC > 100 microg/mL.     

The toxicity of extracts of plant parts of Moringa stenopetala in HEPG2 cells in vitro

The cytotoxicity of extracts from a widely used species of plant, Moringa stenopetala, was assessed in HEPG2 cells, by measuring the leakage of lactate dehydrogenase (LDH) and cell viability. The functional integrity of extract-exposed cells was determined by measuring intracellular levels of ATP and glutathione (GSH). The ethanol extracts of leaves and seeds increased significantly (p < 0.01) LDH leakage in a dose- and time-dependent manner. The water extract of leaves and the ethanol extract of the root did not increase LDH leakage. A highly significant (p < 0.001) decrease in HEPG2 viability was found after incubating the cells with the highest concentration (500 microg/mL) of the ethanol leaf and seed extracts. At a concentration of 500 microg/mL, the water extract of leaves increased (p < 0.01), while the ethanol extract of the same plant part decreased (p < 0.01), ATP levels. The root and seed extracts had no significant effect on ATP levels. The ethanol leaf extract decreased GSH levels at a concentration of 500 microg/mL (p < 0.01), as did the ethanol extract of the seeds at 250 microg/mL and 500 microg/mL (p < 0.05). The water extract of the leaves did not alter GSH or LDH levels or affect cell viability, suggesting that it may be non-toxic, and is consistent with its use as a vegetable. The data obtained from the studies with the ethanol extract of the leaves and seeds from Moringa stenopetala show that they contain toxic substances that are extractable with organic solvents or are formed during the process of extraction with these solvents. The significant depletion of ATP and GSH only occurred at concentrations of extract that caused leakage of LDH. Further investigation with this plant in order to identify the constituents extracted and their individual toxic effects both in vivo and in vitro is warranted. This study also illustrates the utility of cell culture for screening plant extracts for potential toxicity.     

In vitro and in vivo antiplasmodial activity of 'saye', an herbal remedy used in Burkina Faso traditional medicine

'Saye', a traditional medicine used in Burkina Faso, which consists of extracts of Cochlospermum planchonii (rhizome), Cassia alata (leaf) and Phyllanthus amarus (whole plant), showed a significant effect against Plasmodium falciparum and Plasmodium berghei parasites grown in vivo (IC(50) = 80.11 +/- 3.40 microg/mL; ED(50) = 112.78 +/- 32.32 mg/kg). In vitro the activity was lower.     

Toxicological studies on stem bark, leaf and seed kernel of yellow oleander (Thevetia peruviana)

A comparative study of the toxic effects of extracts from stem bark, leaf and seed kernel of yellow oleander (Thevetia peruviana) in albino rats was carried out. Male and female albino rats weighing 150-200 g were administered crude aqueous extracts of stem bark, leaf and seed kernel of the plant by intraperitoneal injection or exposed to baits prepared with the dry extracts of the plant parts. The control groups either received distilled water by injection, or were fed non-poisoned baits. Extracts from all the plant parts were toxic, and produced marked poisoning symptoms that culminated in death. Poisoning symptoms manifested earlier (10 min after treatment) in rats administered aqueous kernel extracts intraperitoneally as against 45 min to several hours in rats poisoned by ingestion of toxicant. Poisoning symptoms indicated serious cardiac, neuromotor and mental malfunctioning, and manifested as tachycardia, arrhythmia, paralysis, ataxia and disorientation. The lethal dose was lowest (507 mg/kg) with the concentrated aqueous kernel extract (CAKE), and highest (5700 mg/kg) with the bait formulated using 40% of the kernel meal - FKM(B). Rats treated by injection with aqueous kernel extract (AKE) died faster within 10 h, than those with the aqueous leaf or stem bark extracts that died after 260 h. No mortality or abnormal behavioural changes were observed among animals in the control groups.     

Antibacterial activity of Harungana madagascariensis leaf extracts

Aqueous extracts of the leaf of Harungana madagascariensis were analysed phytochemically and evaluated for antimicrobial activity against strains of Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa. Glycosides, tannins, saponins, flavonoids and alkaloids were detected in the plant material. B. subtilis, E. coli and S. typhi, but not Ps. aeruginosa, showed susceptibility at MICs of 2.0 and 15.6 mg/mL; and MBCs of 2.0-3.9 mg/mL and 15.6-31.3 mg/mL, respectively, for the cold and hot extracts. Staph. aureus showed susceptibility only to the hot extract. Concentrations of 2.5-10.0 mg/mL of the cold extract killed over 7 log(10) of the test bacterial population within 30-60 min of exposure. The hot extract needed higher concentrations and longer treatment to achieve similar levels of bacterial cell killing. The results provide a rationalization for the traditional use of H. madagascariensis leaf extracts for the treatment of gastrointestinal disorders.     

Inhibitory effects of sudanese medicinal plant extracts on hepatitis C virus (HCV) protease

One hundred fifty-two methanol and water extracts of different parts of 71 plants commonly used in Sudanese traditional medicine were screened for their inhibitory effects on hepatitis C virus (HCV) protease (PR) using in vitro assay methods. Thirty-four extracts showed significant inhibitory activity (>/=60% inhibition at 100 microg/mL). Of these, eight extracts, methanol extracts of Acacia nilotica, Boswellia carterii, Embelia schimperi, Quercus infectoria, Trachyspermum ammi and water extracts of Piper cubeba, Q. infectoria and Syzygium aromaticum, were the most active (>/=90% inhibition at 100 microg/mL). From the E. schimperi extract, two benzoquinones, embelin (I) and 5-O-methylembelin (II), were isolated and found as potent HCV-PR inhibitors with IC(50) values of 21 and 46 microM, respectively. Inhibitory activities of derivatives of I against HCV-PR as well as their effects on other serine proteases were also investigated.Copyright 2000 John Wiley & Sons, Ltd.     

The neuromuscular blockade produced by pure alkaloid,mitragynine and methanol extract of kratom leaves (Mitragyna speciosa Korth.)

Aim of the study

The effects of pure alkaloid, mitragynine and a methanolic extract of kratom leaves were investigated on neuromuscular junction and compound nerve action potential.

Materials and methods

Wistar rats were killed by cervical dislocation and decapitated. The phrenic nerve–hemidiaphragms, hemidiaphragms and sciatic nerve were isolated.

Results

Kratom methanolic extract present at 0.1–1 mg/mL and mitragynine (0.0156 mg/mL) decreased the muscle twitch on the isolated phrenic nerve–hemidiaphragm and hemidiaphragm preparation. Muscle relaxation caused by kratom extract (1 mg/mL) was greater than the effect of mitragynine. Pancuronium and succinylcholine potentiated the effect of kratom extract. It also had a direct relaxation effect on the hemidiaphragm muscle. The muscle relaxation caused by kratom extract was not antagonized by neostigmine, tetraethylammonium and calcium chloride. High concentrations of kratom extract (10–40 mg/mL) and mitragynine (2 mg/mL) blocked the nerve conduction, amplitude and duration of compound nerve action potential.

Conclusions

The mechanism of action of kratom extract might not act as a competitive antagonist of acetylcholine yet its dominant effect was at the neuromuscular junction and not at the skeletal muscle or somatic nerve.     

Investigations of anti-inflammatory and antinociceptive activities of Piper cubeba, Physalis angulata and Rosa hybrida

The anti-inflammatory activities of Piper cubeba (fruit), Physalis angulata (flower) and Rosa hybrida (flower) were determined by carrageenan-induced paw edema, arachidonic acid-induced ear edema and formaldehyde-induced arthritis in mice. The anti-allergic and analgesic activities of these plants were also studied by using 2,4-dinitrofluorobenzene (DNFB)-induced contact hypersensitivity reaction (type IV) and hot plate test in mice, respectively. These plant extracts clearly exhibited inhibitory effects against acute and subacute inflammation by oral administration (200 mg/kg). Also, administration (200 mg/kg, p.o.) of plant extracts for 1 week significantly inhibited type IV allergic reaction in mice (P<0.05). Rosa hybrida showed an analgesic effect against hot plate-induced thermal stimulation at a dose of 200 mg/kg. These results provide support for the use of Rosa hybrida in relieving inflammatory pain, and insight into the development of new agents for treating inflammatory diseases.     

In vitro antimicrobial, anthelmintic and cyclooxygenase-inhibitory activities and phytochemical analysis of Leucosidea sericea

Ethnopharmacological relevance

Leucosidea sericea is used as a vermifuge and in the treatment of ophthalmia by various tribes in southern African countries.

Aim of the study

The study aimed at screening leaves and stems of Leucosidea sericea for pharmacological activity and validating the plant's traditional use. A general phytochemical screening was also carried out.

Materials and methods

Petroleum ether (PE), dichloromethane (DCM), ethanol (EtOH) and water extracts of the plant parts were investigated for antimicrobial, anthelmintic and cyclooxygenase (COX) inhibitory activities. Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and Candida albicans were used for the antimicrobial evaluation. Caenorhabditis elegans was used for the anthelmintic assay using the microdilution technique. Cyclooxygenase-1 and -2 (COX-1 and -2) were used to evaluate the anti-inflammatory potential of the plant extracts. Phytochemical analysis for phenolic compounds, including gallotannins, condensed tannins and flavonoids was done using 50% methanol extracts of the leaves and stems employing spectrophotometric methods.

Results

The leaf extracts exhibited broad spectrum antibacterial activity ranging from 0.025 to 6.25 mg/ml. The most noteworthy minimum inhibitory concentration (MIC) of 0.025 mg/ml was exhibited by PE and DCM leaf extracts against Bacillus subtilis and Staphylococcus aureus, respectively. In the anthelmintic assay, the best minimum lethal concentration (MLC) value of 0.26 mg/ml was observed for the DCM and EtOH leaf extracts. Both leaf and stem organic solvent extracts exhibited high to moderate inhibition against COX-1 and -2 at a screening concentration of 250 μg/ml. At lower concentrations, the extracts displayed a dose-dependent inhibition, with the lowest IC₅₀ values of 0.06 μg/ml (COX-1) and 12.66 μg/ml (COX-2) exhibited by the PE extract of the leaves. Generally, the leaf extracts exhibited better pharmacological activities and contained higher amounts of phenolic compounds than the stem extracts. Alkaloids and saponins were only detected in the leaf and stem extracts, respectively.

Conclusion

The reported results support the local use of Leucosidea sericea against eye infections and as a vermifuge. The pharmacological activities exhibited by the leaf extracts are probably due to their higher phenolic levels.