Lipopolysaccharide increased the acute toxicity of the Rhizoma coptidis extract in mice by increasing the systemic exposure to Rhizoma coptidis alkaloids

Ethnopharmacological relevance

Rhizoma coptidis is used as an antidysenteric in clinics in China. However, patients suffering from dysentery are susceptible to the acute toxicity of Rhizoma coptidis. The current study investigates the effects of lipopolysaccharide (LPS), which are a key pathogenic factor in dysentery, on the acute toxicity of a Rhizoma coptidis extract in mice; possible mechanisms are proposed.

Materials and methods

Acute toxicity and pharmacokinetic experiments in mice were conducted. The plasma concentration of Rhizoma coptidis alkaloids in mice was determined using liquid chromatography/tandem mass spectrometry. The activity of acetylcholinesterase (AChE) in the tissue homogenate was determined using an AChE determination kit.

Results

Pretreatment with LPS for 16 h increased the acute toxicity of the oral Rhizoma coptidis extract. Systemic exposure to Rhizoma coptidis alkaloids was also increased by LPS pretreatment. Neostigmine significantly increased whereas pyraloxime methylchloride reduced the acute toxicity of the Rhizoma coptidis extract. LPS pretreatment alone showed no significant effect on the activity of thoracoabdominal diaphragm AChE. However, it enhanced the inhibitory effect of the Rhizoma coptidis extract. LPS pretreatment did not affect the acute toxicity of various dosages of tail vein-injected berberine.

Conclusions

LPS increased the acute toxicity of the oral Rhizoma coptidis extract in mice by increasing the systemic exposure to the Rhizoma coptidis alkaloids.     

The inhibitory activities of the components of Huang-Lian-Jie-Du-Tang (HLJDT) on eicosanoid generation via lipoxygenase pathway

Aim of the study

Huang-Lian-Jie-Du-Tang (HLJDT) is a traditional Chinese medicine with anti-inflammatory use. In the present study, the effects of its component herbs and pure components were observed on eicosanoid generation to find out the contributory components and their precise targets on arachidonic acid (AA) cascade.

Materials and methods

By monitoring leukotriene B₄ (LTB₄), 5-hydroxyeicosatetraenoic acid (5-HETE), and 12-hydroxy-5,8,10-heptadecatrienoic acid (12-HHT), we compared the effects of HLJDT, HLJDT free of one or two component herbs, and water extract of four single component herbs of HLJDT (Rhizoma coptidis, Radix scutellariae, Cortex phellodendri and Fructus gardeniae) on eicosanoid generation in rat elicited peritoneal macrophages. In addition, thirteen pure compounds from HLJDT (baicalin, baicalein, wogonoside, wogonin, berberine, magnoflorine, phellodendrine, coptisine, palmatine, jateorrhizine, crocin, chlorogenic acid, and geniposide) were tested in the macrophages. Furthermore, the efficacies of these thirteen compounds were evaluated on cell-free purified enzymes: leukotriene A₄ hydrolase (LTA₄H), 5-, 15-lipoxygenase (5-, 15-LO), and cyclo-oxygenase-1/2 (COX-1/2). Moreover, the possible synergetic effect on LO pathway derived LTB₄ generation between the active components was also tested in rat peritoneal macrophages.

Results

Our experiments showed that Rhizoma coptidis and Radix scutellariae were responsible for the suppressive effect of HLJDT on eicosanoid generation. Some of the pure components including baicalein, baicalin, wogonoside, wogonin, coptisine, and magnoflorine inhibited eicosanoid generation in rat macrophages via LO pathway of AA cascade. Further experiments on cell-free purified enzymes confirmed that Radix scutellariae derived baicalein and baicalin showed significant inhibition on 5-LO and 15-LO, while Rhizoma coptidis derived coptisine showed medium inhibition on LTA₄H. On the other hand, no significant inhibition of thirteen components on COX-1/2 was observed. Moreover, the slight synergetic inhibition on LTB₄ between baicalein and coptisine was proved in the rat peritoneal macrophages.

Conclusions

Baicalein and coptisine, the active components of HLJDT, for the first time are found to interfere with arachidonic acid cascade via inhibition on different points of LO pathway. This finding makes the mechanism of HLJDT clearer and achieves its safer therapeutic application.     

Identification of the toxic constituents in Rhizoma Coptidis

Aim of the study

Rhizoma Coptidis (Huanglian) is a widely used Traditional Chinese Medicine. However, it causes human as well as animal toxicities. In this study, we aimed to ascertain the toxic constituents in Rhizoma Coptidis.

Materials and methods

The acute toxicity of both the total extract and the alkaloid-rich extract of Rhizoma Coptidis were tested in mice. The dose related tissue concentration of the Rhizoma Coptidis alkaloids in mice was determined using high performance liquid chromatography with ultraviolet detection. The influence of phenobarbital sodium [a non-selective hepatic enzyme (P450) inducer] on the acute toxicity of Rhizoma Coptidis as well as the tissue concentration of the alkaloids was investigated. The cytotoxicity of the Rhizoma Coptidis alkaloids was tested in six cell lines using the MTT assay.

Results

The median acute oral lethal dose of the total extract of Rhizoma Coptidis was 2.95 g/kg in mice. The alkaloid-rich extract was much more toxic than the total extract of Rhizoma Coptidis. Four Rhizoma Coptidis alkaloids were detected in brain, heart, and lung tissues of mice that received the oral total extract of Rhizoma Coptidis. Tissue concentration increased nonlinearly with higher doses. Phenobarbital sodium decreased the tissue concentration of every alkaloid as well as the toxicity of Rhizoma Coptidis. All alkaloids, especially berberine, showed dose and time dependent cytotoxicity.

Conclusions

The toxic constituents of Rhizoma Coptidis were the alkaloids, mainly berberine.     

In vitro antiplasmodial activity of indole alkaloids from the stem bark of Geissospermum vellosii

Ethnopharmacological relevance

The stem bark of Geissospermum vellosii has been traditionally used by the native population of northern South America to treat malaria. Indole alkaloids have been previously isolated from this plant, but the antiplasmodial constituents have not yet been described. As part of our ongoing investigations of new bioactive compounds with activity against malaria parasites, we tested the in vitro antiplasmodial activity of isolated fractions and purified alkaloids from Geissospermum vellosii.

Materials and methods

Indole alkaloids were isolated and identified from a methanolic crude extract of Geissospermum vellosii bark using a combination of high performance counter current chromatography, mass spectrometry and nuclear magnetic resonance technologies. The methanolic extract, the crude alkaloid fractions and the purified compounds were tested for in vitro antiplasmodial activity against the chloroquine-sensitive strain of Plasmodium falciparum (D10).

Results

An indole alkaloid (4) along with four known indole alkaloids, geissolosimine (1), geissospermine (2), geissoschizoline (3), and vellosiminol (5) were isolated and structure elucidated. The antiplasmodial activity (IC₅₀) of the methanolic crude extract was 2.22 μg/mL, while for the isolated compounds it ranged from 0.96 μM to 13.96 μM except for (5) which showed a low activity (157 μM). Geissolosimine (1) showed the highest antiplasmodial activity (0.96 μM).

Conclusions

This study provides evidence to support the use of Geissospermum vellosii as an antimalarial agent, as used by the native populations. Geissolosimine (1) is a lead molecular structure for possible antimalarial drug development.     

Rhizoma coptidis and berberine-induced activation of murine microglia N9 cells

Aims of the study

To investigate the effect of water extract of Rhizoma coptidis (WEC) and berberine on the activation of murine microglia N9 cells and corresponding mechanism related to mitochondria.

Materials and methods

Phagocytic activity of murine microglia N9 cells was measured by neutral red staining method after the cells were treated with various concentrations of WEC and alkaloids for 24 h. Flow cytometric analysis was performed to determine the level of intracellular ROS, Ca²⁺, and mitochondrial transmembrane potential (Δψ) after 87 μg/ml of WEC and 12.4 μg/ml of berberine treatment. Global changes of gene expression in WEC- and berberine-treated N9 cells were measured using cDNA microarray.

Results

WEC and berberine, but not palmatine and jatrorrhizine, enhanced phagocytic activity of murine N9 cells in a dose-dependent manner. Both of WEC and berberine stimulated free radical generation, enhanced mitochondrial Δψ and induced gene expression of Ndufab1, Cox6a2 and Atp5a1. However, a more significant phagocytic effect was observed for WEC. WEC, but not berberine, increased intracellular Ca²⁺ concentration. The gene expression of Atp5c1 was selectively up-regulated by WEC, while three genes of Uqcrq, Cox8b, and Atp5g2 were induced by berberine.

Conclusions

WEC and berberine activated murine microglia N9 cells by the regulation of mitochondrial function and mitochondria-related signal molecules. The action of WEC is stronger than that of berberine, indicating that the effect of WEC is ascribed partially, but not totally, to berberine.     

Iridoids as chemical markers of false ipecac (Ronabea emetica), a previously confused medicinal plant

Ethnopharmacological relevance

Several roots or rhizomes of rubiaceous species are reportedly used as the emetic and antiamoebic drug ipecac. True ipecac (Carapichea ipecacuanha) is chemically well characterized, in contrast to striated or false ipecac derived from the rhizomes of Ronabea emetica (syn. Psychotria emetica). Besides its previous use as substitute of ipecac, the latter species is applied in traditional medicine of Panama and fruits of its relative Ronabea latifolia are reported as curare additives from Colombia.

Materials and methods

Compounds of Ronabea emetica were isolated using standard chromatographic techniques, and structurally characterized by NMR spectroscopy and mass spectrometry. Organ specific distribution in Ronabea emetica as well as in Ronabea latifolia was further assessed by comparative HPLC analysis.

Results

Four iridoid-glucosides, asperuloside (1), 6α-hydroxygeniposide (2), deacetylasperulosidic acid (3) and asperulosidic acid (4) were extracted from leaves of Ronabea emetica. Rhizomes, used in traditional medicine, were dominated by 3. HPLC profiles of Ronabea latifolia were largely corresponding. These results contrast to the general tendency of producing emetine-type and indole alkaloids in species of Psychotria and closely related genera and merit chemotaxonomic significance, characterizing the newly delimited genus Ronabea.

Conclusions

The aim of the work was to resolve the historic problem of adulteration of ipecac by establishing the chemical profile of Ronabea emetica, the false ipecac, as one of its less known sources. The paper demonstrates that different sources of ipecac can be distinguished by their phytochemistry, thus contributing to identifying adulterations of true ipecac.     

Sedative, hypnotic and anticonvulsant activities of the ethanol fraction from Rhizoma Pinelliae Praeparatum

Ethnopharmacological relevance

Rhizoma Pinelliae Praeparatum is the product of raw Rhizoma Pinellia processed with alkaline solution and Licorice, which had been widely used for treatment of insomnia in traditional Chinese medicine. The present study aimed to investigate the sedative, hypnotic and anticonvulsant activities of ethanol fraction from Rhizoma Pinelliae Praeparatum (EFRP) and to determine whether these effects were related to GABAergic mechanism.

Materials and methods

The sedative, hypnotic and anticonvulsant activities of EFRP were investigated with locomotion activity, pentobarbital-induced sleeping and nikethamide (NKTM)-induced convulsion tests, respectively. Additionally, the effects of flumazenil (an antagonist of GABA_A receptor) and l-malic acid (blocker of synthetic enzyme for GABA) on the hypnotic activity of EFRP were evaluated.

Results

EFRP at dose of 12 g/kg significantly inhibited the locomotion activity of mice. EFRP showed synergic effect on pentobarbital-induced sleeping by increased numbers of mice falling asleep, reduced the sleep latency and prolonged the sleeping time. l-malic acid and flumazenil inhibited the augment effects of EFRP on pentobarbital-induced sleeping. EFRP promoted a significant protection to NKTM-induced convulsion, by prolonged the death latency and decreased mortality.

Conclusion

EFRP possessed sedative, hypnotic and anticonvulsant activities and these activities may be related to the GABAergic system.     

Chemical constituents from the stem bark of Symplocos paniculata Thunb. with antimicrobial, analgesic and anti-inflammatory activities

Ethnopharmacological relevance

The stem bark of Symplocos paniculata Thunb. has been used to check abortion in folk medicine in India.

Aim of the study

The present study was undertaken to isolate the phytochemicals from the plant together with the evaluation of antimicrobial, analgesic and anti-inflammatory activities of the plant extract and isolated compounds.

Materials and methods

The plant extract was subjected to column chromatography for isolation of phytochemicals. The agar diffusion method was adopted for antimicrobial activity to determine MICs. Ethanolic extract and isolated compounds were selected for investigating their analgesic activity on acetic acid-induced writhing response in mice. The anti-inflammatory activity was performed on carrageenan-induced paw edema in rats.

Results

The stem bark of the plant afforded seven compounds, 4-(8-hydroxyethyl) cyclohexan-1-oic acid (1); androst-5(6)-ene 17-one 3β-O-(β-d-glucopyranoside) (2); 9β,25-cyclo 3β-O-(β-d glucopyranosyl)-echynocystic acid (3); 9β,19-cyclo 24-methylcholan-5,22-diene 3β-O-{β-d-glucopyranosyl (1 → 6) α-l-rhamnopyranoside} (4); 30-ethyl 2α,16α-dihydroxy 3β-O-(β-d-glucopyranosyl) hopan-24-oic acid (5); 32,33,34-trimethyl-bacteriohopan-16-ene 3-O-β-d-glucopyranoside (6) and flavone 3′,4′,5′,6-tetramethoxy 7-O-β-d-glucopyranosyl (1 → 3) β-d-glucopyranoside (7). The extract and isolated compounds exhibited antimicrobial, analgesic and anti-inflammatory activities.

Conclusion

The present study concludes that ethanolic extract of the plant and its constituents having significant antimicrobial, analgesic and anti-inflammatory activities.     

Antitussive, expectorant and anti-inflammatory activities of four alkaloids isolated from Bulbus of Fritillaria wabuensis

Ethnopharmacological relevance

Bulbus Fritillaria Cirrhosae (BFC), known by the Chinese name “Chuan-Bei-Mu”, is used as an antitussive, antiasthmatic and expectorant drug for more than 2000 years in China, and Bulbus of Fritillaria wabuensis S. Y. Tang & S. C. Yueh (BFW) was recorded in the 2010 edition of China Pharmacopoeia as one of sources for BFC. The primary objective of this study was to evaluate the antitussive, expectorant and anti-inflammatory effects of alkaloids - imperialine, imperialine-β-N-oxide, isoverticine, and isoverticine-β-N-oxide, which were isolated from BFW, and to provide experimental evidence for its traditional use.

Materials and methods

The alkaloids were isolated using phytochemical methods, and their structures were determined by spectroscopic analysis. Their antitussive effects were measured using murine model of ammonia induced cough, the expectorant effects were evaluated by measuring mice's tracheal phenol red output, and the anti-inflammatory effects were assessed by using the murine model of xylene induced ear edema.

Results

The structures of the four alkaloids - imperialine, imperialine-β-N-oxide, isoverticine, and isoverticine-β-N-oxide isolated from BFW were confirmed. The four alkaloids significantly inhibited cough frequency and increased latent period of cough in mice induced by ammonia. Imperialine and isoverticine showed obviously antitussive activities in a dose-dependent manner. Besides, the four alkaloids markedly enhanced mice's tracheal phenol red output in expectorant assessment and significantly inhibited the development of ear edema in anti-inflammatory evaluation assay. Moreover, significant differences were found between the structure-activity relationships of the four alkaloids.

Conclusions

The four alkaloids exhibited significant antitussive, expectorant and anti-inflammatory activities. We suggest that they may be the active ingredients of BFW. The results of the present study provided evidence for BFW to be used as an antitussive and expectorant Traditional Chinese Medicine (TCM).     

Anti-diabetic activity of Chiliadenus iphionoides

Ethnopharmacological relevance

Chiliadenus iphionoides (Boiss. & Blanche) Brullo (Asteraceae), a small aromatic shrub found throughout Israel, is used traditionally in the treatment of diabetes mellitus. In this study, Chiliadenus iphionoides anti-diabetic activity was characterized using cellular and animal models.

Materials and methods

Pancreatic β cells, adipocytes, and skeletal myotubes were treated with an ethanolic extract of Chiliadenus iphionoides to study the extract's effects on insulin secretion and glucose uptake. The sand rat (Psammomys obesus) was used to study Chiliadenus iphionoides acute and long term effects in vivo. An oral starch tolerance test was performed as well as a 30 day feeding study.

Results

Chiliadenus iphionoides extract increased insulin secretion in β cells as well as glucose uptake in adipocytes and skeletal myotubes. The extract also displayed hypoglycemic activity in the diabetic sand rat.

Conclusions

Chiliadenus iphionoides exhibits considerable anti-diabetic activity, although the mechanism of action remains to be determined.     

Anti-angiogenic activity of Gynura segetum leaf extracts and its fractions

Ethnopharmacological relevance

Gynura segetum is a popular medicinal plant in Indonesia and Malaysia, known to possess various medicinal properties especially for treatment of cancer, diabetes and hypertension.

Aim of the study

This study was carried out to evaluate the anti-angiogenic effect of Gynura segetum leaves extracts and its fractions. The chemical compositions of the active extracts were also determined.

Materials and methods

The anti-angiogenic activity of Gynura segetum leaves extracts and its fractions was evaluated in vivo using the chick embryo chorioallantoic membrane (CAM) assay. Gas chromatography-mass spectrometry (GC-MS) analysis was carried out to identify the chemical compositions of the active extracts.

Results

The CAM treated with Gynura segetum leaves extracts and its fractions (100 μg/disc) showed a significantly greater anti-angiogenic effect compared to the positive control suramin (50 μg/disc). Chemical analysis of the active extracts from the leaves of Gynura segetum yielded nine known compounds: undecane (1), neophytadine (2), hexadecanoic acid, methyl ester (3), 9,12-octadecadienoic acid, methyl ester (4), 9,12,15-octadecatrienoic acid, methyl ester (5), phytol (6), tetradecanal (7), octadecanoic acid, methyl ester (8) and γ-sitosterol (9).

Conclusions

These results suggested that Gynura segetum has anti-angiogenic activity. The plant may be used as a potential source for protection against cancer.     

Gastrodia elata prevents huntingtin aggregations through activation of the adenosine A₂A receptor and ubiquitin proteasome system

Ethnopharmacological relevance

Gastrodia elata Blume (Fam. Orchidaceae) is a traditional Chinese herbal medicine for treating headaches, dizziness, tetanus, epilepsy, and numbness of the limbs, which suggests that it has neuroprotective effect.

Aim of the study

To validate the neuroprotection of Gastrodia elata in preventing neurodegenerations, such as Huntington's disease (HD).

Materials and methods

MTT assay was used to validate the protection of Gastrodia elata. In pheochromocytoma (PC12) cell. Transient transfection of mutant huntingtin (Htt) in PC12 cell was used as an in vitro model of HD. Filter retardation assay was used to measure Htt-induced protein aggregations. Proteasome activity was monitored by transfection of pZsProSensor-1 and imaged by a confocal laser scanning microscope.

Results

This protection of Gastrodia elata could be blocked by an A_2A-R antagonist and a protein kinase A (PKA) inhibitor, indicating an A_2A-R signaling event. Gastrodia elata could reverse mutant Htt-induced protein aggregations and proteasome de-activation through A_2A-R signaling. In addition, activation of PKA tended to activate proteasome activity and reduce mutant Htt protein aggregations. The proteasome inhibitor, MG 132, blocked Gastrodia elata-mediated suppression of mutant Htt aggregations.

Conclusion

Gastrodia elata prevented mutant Htt aggregations and increased proteasomal activity by targeting the A_2A-R through PKA-dependent pathway.     

Intracellular replication inhibitory effects of Galla Rhois ethanol extract for Brucella abortus infection

Ethnopharmacological relevance

Galla Rhois (GR) has long been applied in traditional Korean and Oriental medicine. Although GR has an anti-bacterial effect, the anti-bacterial mechanism and therapeutic efficiency of GR for intracellular parasitic Brucella infection are still unclear.

Aim of the study

The objective of this study was to investigate the antibacterial and therapeutic effects of GR ethanol extract (GRE), which is a natural antibacterial component for the treatment of Brucella abortus infection.

Materials and methods

The antibacterial activity of GRE towards Brucella abortus was evaluated by incubating Brucella abortus with GRE. Following treatment with GRE, Brucella abortus adherence, uptake, intracellular growth, and intracellular trafficking in macrophages were monitored. Mice were infected intraperitoneally with Brucella abortus and treated orally with GRE for 14 days, and then the weight and CFUs from each spleen were monitored.

Results

The viability of Brucella abortus was markedly decreased in a dose-dependent manner. Moreover, Brucella abortus internalization and intracellular growth within macrophages were reduced in GRE-treated cells. The number of bacteria that adhered to GRE-pretreated cells was significantly lower than that of untreated cells. With regards to intracellular trafficking, treatment with GRE augmented the colocalization of Brucella abortus-containing phagosomes with LAMP-1. GRE-treated mice showed considerably decreased weight and bacterial burdens in the spleen compared to untreated mice.

Conclusion

GRE exhibits antibacterial and protective effects on Brucella abortus in vitro and in vivo. These results highlight the beneficial effects of GRE in the prevention and treatment of brucellosis.     

Anti-inflammatory properties of Ajuga bracteosa in vivo and in vitro study and their effects on mouse model of liver fibrosis

Ethnopharmacological relevance

The entire plant of Ajuga bracteosa Wall has been used to treat various inflammatory disorders, including hepatitis, in Taiwan.

Aim

This study evaluated the hepatoprotective ability of Ajuga bracteosa extract (ABE).

Materials and methods

We investigated the inhibitory action of a chloroform fraction of ABE (ABCE) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells and Kupffer cells. Hepatic fibrosis was induced in mice through the administration of CCl₄ twice a week for 8 weeks. Mice in three CCl₄ groups were treated daily with water and ABE throughout the duration of the experiment.

Results

In LPS-stimulated RAW264.7 cells and Kupffer cells, ABCE inhibited the production of NO and/or TNF-α and also blocked the LPS-induced expression of NO synthase. ABCE inhibited the activation of NF-κB induced by LPS, associated with the abrogation of IκBα degradation, with a subsequent decrease in nuclear p65 and p50 protein levels. The phosphorylation of MAPKs in LPS-stimulated RAW264.7 cells was also suppressed using ABCE. In the in vivo study, ABE protected the liver from injury by reducing the activity of plasma aminotransferase, and by improving the histological architecture of the liver. RT-PCR analysis showed that ABE inhibited the hepatic mRNA expression of LPS binding protein, CD14, TNF-α, collagen(α1)(I), and α-smooth actin.

Conclusion

These results indicate that ABE alleviated CCl₄-induced liver fibrosis, and that this protection is probably due to the suppression of macrophage activation.     

Effects of Curcuma comosa on the expression of atherosclerosis-related cytokine genes in rabbits fed a high-cholesterol diet

Aim of the study

Curcuma comosa has been known to have potential use in cardiovascular diseases, but its immunoregulatory role in atherosclerosis development and liver toxicity has not been well studied. We therefore investigated the effects of Curcuma comosa on the expression of atherosclerosis-related cytokine genes in rabbits fed a high-cholesterol diet.

Materials and methods

Twelve male New Zealand White rabbits were treated with 1.0% cholesterol for one month and were subsequently treated with 0.5% cholesterol either alone, or in combination with 5 mg/kg/day of simvastatin or with 400 mg/kg/day of Curcuma comosa powder for three months. The expression of IL-1, MCP-1, TNF-α, IL-10, and TGF-β in the isolated abdominal aorta and liver were determined by real-time RT-PCR. Liver toxicity was determined by hepatic enzyme activity.

Results

Curcuma comosa significantly decreased the expression of pro-inflammatory cytokines, leading to a stronger reduction in IL-1, MCP-1, and TNF-α expression compared to that was suppressed by simvastatin treatment. However, neither Curcuma comosa nor simvastatin affected the expression of anti-inflammation cytokines. In the liver, Curcuma comosa insignificantly decreased the expression of pro-inflammatory cytokines and significantly increased the expression of the anti-inflammatory cytokine IL-10 without altering the activity of hepatic enzymes. In contrast, simvastatin significantly increased the MCP-1 and TNF-α expressions and serum ALT level, without affecting the expression of anti-inflammatory cytokines.

Conclusions

In this study, we demonstrated that Curcuma comosa exerts anti-inflammatory activity in the aorta and liver without causing liver toxicity, indicating that Curcuma comosa is a potential candidate as an alternative agent in cardiovascular disease therapy.     

Increased sexual motivation in female rats treated with Humulus lupulus L. extract

Aim of the study

To evaluate the influence of Humulus lupulus extract on sexual behavior in female rats.

Materials and methods

Ovariectomized rats hormonally primed with estradiol benzoate (1.5 μg/rat) and progesterone (500 μg/rat) were acutely treated by oral gavage with Humulus lupulus extract dosed at 5, 10 and 25 mg/kg and then tested for partner preference and sexual receptivity.

Results

The administration of Humulus lupulus extract at the highest dose significantly increased the preference for the stimulus male during the partner preference test and the number of proceptive behaviors during the receptivity test, without affecting the lordosis response.

Conclusions

Humulus lupulus extract increased sexual motivation in hormone-primed female rats.     

Anticonvulsant activity of aqueous root extract of Ficus religiosa

Ethnopharmacological relevance

Ficus religiosa Linn is frequently used for the treatment of nervous disorders among Pawara tribe of the Satpuda range, India.

Aim of the study

This study aimed to investigate the anticonvulsant activity of the aqueous aerial root extract of Ficus religiosa in chemoconvulsant-induced seizures in mice.

Materials and methods

The anticonvulsant activity of the extract (25, 50 and 100 mg/kg, p.o.) was investigated in strychnine-, pentylenetetrazole-, picrotoxin- and isoniazid-induced seizures in mice. Rat ileum and fundus strip preparations were used to study the effect of the extract on acetylcholine (Ach)- and serotonin (5-HT)-induced contractions, respectively.

Results

The extract showed no toxicity and protected the animals in the strychnine and pentylenetetrazole tests in a dose-dependent manner. Its effect in the picrotoxin and isoniazid tests, however, was less potent. The extract also exhibited dose-dependent potentiation of Ach in rat ileum but failed to potentiate the effect of 5-HT in rat fundus strip preparation.

Conclusions

The results suggest that an orally administered aqueous root extract of Ficus religiosa has dose-dependent and potent anticonvulsant activities against strychnine- and pentylenetetrazole-induced seizures. The observed activities may be ascribed to the appreciable content of zinc and magnesium in the extract.     

Antidiabetic activity of alcoholic stem extract of Nervilia plicata in streptozotocin-nicotinamide induced type 2 diabetic rats

Ethnopharmacological relevance

Nervilia plicata (Orchidaceae) has long been used in the antidiabetic medicinal preparations of traditional healers of Wayanad (Kerala), but recuperative potential of the plant was remained undefined. We demonstrated the regenerative potential of the plant extract on kidney affected by type 2 diabetes besides lowering blood glucose.

Aim of the study

The aim of the current study was to investigate the recuperative and regenerative potential of alcoholic stem extract of Nervilia plicata on streptozotocin-nicotinamide induced type 2 diabetic models.

Materials and methods

Non insulin dependent diabetes mellitus (NIDDM) was induced in overnight fasted rats by intramuscular injection (IMI) of 60 mg/kg STZ and 120 mg/kg of nicotinamide after 5 min interval. Blood glucose was assessed by a glucometer, serum urea and creatinine levels were determined by diacetylmonooxime method and Jaffe reaction respectively. Kidney sections were taken and stained with Masson's tri-dye and Periodic Acid Schiff (PAS) and examined for structural changes. Also lipid peroxidation product (LPP) levels were determined as thio barbituric acid reactive substance levels (TBARS) method.

Results

On administration of 5 mg/kg of plant extract, blood glucose levels of the NIDDM rats showed 62.00 and 76.29% decrease in the blood glucose levels on day 0 and day 30 respectively. Damages caused to the kidney tissue were negligible or not seen. Serum urea and creatinine levels showed 61.49 and 70.96% decrease on day 30. LPP levels of kidney and pancreas showed 70.58 and 77.41% decrease respectively.

Conclusion

These results demonstrate significant antidiabetic and regenerative potential of the Nervilia plicata, justifying the use of plant in the indigenous system of medicine. Isolation and characterisation of the compound(s) playing pivotal role in the cure would open new vistas in the therapy of type 2 diabetes.