Evaluation of antinociceptive effects of Crassocephalum bauchiense Hutch (Asteraceae) leaf extract in rodents

Ethnopharmacological relevance

The leaves of Crassocephalum bauchiense have long been used in traditional Cameroonian medicine for the treatment of epilepsy, pain, inflammatory disorders, arthritis and intestinal pain.

Aim of the study

In this study, we attempted to identify the possible antinociceptive action of the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum baucheiense.

Materials and methods

Using acetic acid induced abdominal constrictions, formalin-, capsaisin- and glutamate-induced nociception, and hot plate assay procedures, the antinociceptive effects of the aqueous extract and the alkaloid fraction was assessed after oral administration in mice. Morphine sulfate was used as reference analgesic agent. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of the extracts of Crassocephalum bauchiense. Male and female Swiss mice were used to assess acute toxicity of these extracts.

Results

The aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced a significant antinociceptive effects in the acetic acid, formalin, glutamate, capsaicin and hot plate tests. These antinociceptive effects of Crassocephalum bauchiense were significantly attenuated by pretreatment with naloxone. The extracts of Crassocephalum bauchiense did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to the aqueous extract and the alkaloid fraction, so it was not possible to calculate the LD₅₀.

Conclusion

The results confirm the popular use of Crassocephalum bauchiense as an antinociceptive, and contribute to the pharmacological knowledge of this species because it was shown that the aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced dose related antinociception in models of chemical and thermal nociception through mechanisms that involve an interaction with opioidergic pathway.     

Antipsychotic and sedative effects of the leaf extract of Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae) in rodents

ETHNOPHARMACOLOGICAL RELEVANCE: Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae) has been used as a medicine for the treatment of epilepsy, insomnia, dementia and psychotic disorders in Cameroonian traditional medicine. AIM OF THE STUDY: This study was designed to examine whether the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum bauchiense possess antipsychotic and sedative properties in rodents. MATERIALS AND METHODS: The rectal temperature of mice was recorded with a probe thermometer at a constant depth. Novelty-induced rearing behavior is used to evaluate a central excitatory locomotor behavior in mice. The antipsychotic effects of the extracts were assessed using the apomorphine animal model of psychosis. The catalepsy test was tested based on the ability of the leaves extracts of Crassocephalum bauchiense to alter the duration of akinesia by placing the naive mice with both forelegs over a horizontal bar. The extracts of Crassocephalum bauchiense effects were evaluated on sodium pentobarbital-induced sleeping time. In addition, gamma-aminobutyric acid concentrations in the brain treated mice were also estimated. RESULTS: The aqueous extract and the alkaloid fraction from Crassocephalum bauchiense caused dose-dependent inhibition of novelty-induced rearing behavior, decreased the apomorphine-induced stereotypy and fighting, and had significant fall of the body temperature. The aqueous extract prolonged the sodium pentobarbital sleeping time. This prolongation was not reversed by bicuculline, a light-sensitive competitive antagonist of GABA(A) receptors complex. However, the effect of the aqueous extract on sodium pentobarbital-induced sleeping time was blocked by N-methyl-β-carboline-3-carboxamide, a partial inverse agonist of the benzodiazepine site in the GABA(A) receptor complex and flumazenil, a specific antagonist of the benzodiazepine site in the GABAA receptor complex. In biochemical experiments, the concentration of the inhibitory amino acid, gamma-aminobutyric acid, was significantly increased in the brain of animals treated with the aqueous extract of Crassocephalum bauchiense and sodium valproate. CONCLUSIONS: The results show that the antipsychotic and sedative properties of Crassocephalum bauchiense are possibly mediated via the blockade of dopamine D-2 receptors and GABAergic activation, respectively. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for these neuropharmacological actions and also to identify the active substances present in the extracts of Crassocephalum bauchiense.     

Sedative, antiepileptic and antipsychotic effects of Viscum album L. (Loranthaceae) in mice and rats

Ethnopharmacological relevance

Viscum album L. is claimed in traditional medical practice, to be useful in the treatment of epilepsy and insomnia in Himachal Pradesh, India.

Materials and methods

The effect of Viscum album L. on epilepsy, psychosis and sedative activity was evaluated in mice and rats using standard procedure.

Results

The aqueous leaf extract of Viscum album L. prolonged the pentobarbital induced sleeping time and reduced the locomotor activity in actophotometer. This suggests that reduced locomotor activity facilitate GABAergic transmission. In addition the extract reduced MES, INH and PTZ-induced convulsions which suggest that there may be possibility of blocking Na⁺ channels, opening of Cl⁻channels or enhancing the GABAergic system. The extract decreased the apomorphine-induced stereotyped behavior and potentiates the HAL-induced cataleptic score which suggests the extract possess antidopaminergic activity.

Conclusion

The results obtained in present study suggested that title plant exhibited sedative, antiepileptic and antipsychotic activity in mice and rats.     

Neuropharmacological study of Dracocephalum moldavica L. (Lamiaceae) in mice: sedative effect and chemical analysis of an aqueous extract

Ethnopharmacological relevance

Dracocephalum moldavica is used as a tranquilizer and as remedy for nervous conditions relief in the Mexican traditional medicine. Despite its intensive use no literature reported neuropharmacological studies on Dracocephalum moldavica as yet.

Aim of the study

The sedative, anxiolytic-like and antidepressant-like effects of the aqueous extract of aerial parts of Dracocephalum moldavica (Lamiaceae) (DM) were evaluated in behavioral models in mice. The general toxic effects of DM were evaluated as well as their chemical analysis was performed.

Materials and methods

DM effects were evaluated on pentobarbital-induced sleeping time (SPT), the hole-board (HBT), and the avoidance exploratory behavior (AEBT) tests and on the forced swimming test (FST). General activity and motor coordination were evaluated in the open field (OFT) and Rota-rod tests, respectively. The acute toxicity of DM was determinate by its LD₅₀ dose. The chemical analyses DM were performed by chromatographic and HPLC–ESI-MS techniques.

Results

DM prolonged the pentobarbital-induced sleeping time, induced sedation in the HBT, decreased spontaneous activity and produced motor coordination impairment in mice. However, DM did not show anxiolytic effects in the AEBT or HBT and it was not effective in FST. The DM-treatment produced mortalities with LD₅₀ = 470 mg/kg body weight.The HPLC–ESI-MS analysis of DM revealed that (acacetin, apigenin and luteolin)-7-O-β-d-(6″-O-malonyl)-glucoside derivates are the main compounds of DM.

Conclusions

DM induced sedative actions and a general inhibition of CNS activity observed by the decrease of animals’ general activity, motor coordination and exploration.     

Anti-inflammatory and analgesic effects of ethanol and aqueous extracts of Pterocephalus hookeri (C.B. Clarke) Höeck

Aim of the study

This study evaluates the anti-inflammatory and analgesic activities of the ethanol and aqueous extracts of a Tibetan herb Pterocephalus hookeri (C.B. Clarke) Höeck to provide experimental evidence for its traditional use such as cold, flu and rheumatoid arthritis.

Materials and methods

Investigations on the analgesic effects of P. hookeri (C.B. Clarke) Höeck were carried out, including hot-plate test and acetic acid-induced writhing. The anti-inflammatory activities were observed by utilizing the following models: carrageenin-induced edema of the hind paw of rats, cotton pellet-induced granuloma formation in rats, acetic acid-induced permeability, and xylene-induced ear edema in mice. The effects of the administration of indomethacin were also studied.

Results

It has been shown that the ethanol and aqueous extracts significantly increased the hot-plate pain threshold and reduced acetic acid-induced writhing response in mice. The ethanol and aqueous extracts remarkably inhibited the increase in vascular permeability induced by acetic acid and ear edema induced by xylene. The ethanol extract also significantly decreased the carrageenin-induced rat paw edema perimeter and inhibited the increase of granuloma weight.

Conclusion

The results show that the ethanol and aqueous extracts have both central and peripheral analgesic activities and as anti-inflammatory effects, supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.     

Depressant effects of Clinopodium mexicanum Benth. Govaerts (Lamiaceae) on the central nervous system

Ethnopharmacological relevance

The decoction of leaves of Clinopodium mexicanum Benth. Goaverts (Lamiaceae), commonly known as “Toronjil de Monte”, is used in the Mexican traditional medicine to induce sleep, as well as sedative and analgesic remedy.

Aim of the study

To evaluate the putative depressant effects of an aqueous extract of the medicinal plant Clinopodium mexicanum on the central nervous system (CNS).

Materials and methods

The effects of the extract (AECM) on mice were tested in several animal paradigms, including sodium pentobarbital-induced sleep, open field tests, and hole-board tests. The effects of AECM on pentylenetetrazole- and picrotoxin-induced convulsions in mice and on the antithermonociceptive response in the hot-plate paradigm were also tested. Additionally, the active extract (AECM) was analyzed with HPLC–ESI-MS techniques.

Results

Mice acutely treated with AECM at 100, 200, 500 and 1000 mg/kg doses prolonged the sleeping time induced by sodium pentobarbital (42 mg/kg). This extract, at 100 and 200 mg/kg doses, showed a sedative effect in the hole-board paradigm and decreased spontaneous activity in mice. AECM at 10, 100 and 200 mg/kg prolonged the onset of seizures induced by pentylenetetrazole (90 mg/kg) and antagonized tonic convulsions induced by picrotoxin (10 mg/kg). Additionally, AECM inhibited the response to a thermonociceptive stimulus. The intraperitoneal AECM treatment produced mortality with an LD₅₀ = 2154 mg/kg. Chemical analysis showed that the flavanone glycosides neoponcirin, poncirin, and isonaringenin are the main compounds of the active extract.

Conclusions

This study demonstrates that an acutely administered single dose of an aqueous extract of Clinopodium mexicanum can exert depressant effects on the CNS. These findings are in agreement with the traditional use of Clinopodium mexicanum to induce sleep as well as sedative and analgesic remedy. The chemical analysis of AECM revealed the presence of the flavanone glycosides neoponcirin, poncirin, and isonaringin.     

Isolation of jacaranone,a sedative constituent extracted from the flowers of the Mexican tree Ternstroemia pringlei

Ethnopharmacological relevance

Ternstroemia pringlei represents one of the most widely employed and commercially exploited medicinal plant in Mexico, used popularly as a tranquilizer and for the treatment of insomnia.

Aim of the study

To investigate the sedative constituents of the plant through a bio-guided fractionation of extracts derived from calyx and fruits.

Materials and methods

Crude extracts with different polarities (CHCl₃, AcOEt, MeOH, aqueous) were prepared and subjected to chromatographic fractionation, leading to the isolation of the sedative compound (1) from the MeOH crude extract. The identity of 1 was unequivocally established by means of 1D and 2D NMR spectroscopic analysis. The sleeping time induced by sodium pentobarbital and the elevated plus-maze models were performed on mice to determine the sedative and anxiolytic activities, respectively. Bioactivity was also investigated though in vitro GABA release experiments using mice brain slices.

Results

The sedative compound was established as jacaranone (1), and its effect was clearly demonstrated through a dose-dependent response analysis (ED₅₀ = 25 mg/kg mouse weight). When tested in the elevated plus-maze model, none of the extracts from Ternstroemia pringlei displayed anxiolytic activity. GABA release experiments showed that the MeOH and aqueous crude extracts released this neurotransmitter at a ratio of 217 and 179 pmol/g protein, respectively, evidencing the presence of other bioactive constituents in the extracts apart of 1, whose activity was absent in this model.

Conclusions

Although 1 has been isolated and identified in a number of plant species, this is the first time that its sedative effect has been demonstrated. No previous record exists of other sedative compounds having been isolated from Ternstroemia pringlei.     

Estimation of anti-inflammatory,antinociceptive and antioxidant activities on Arctium minus (Hill) Bernh. ssp. minus

Ethnopharmacological relevance

Arctium minus (Hill) Bernh. ssp. minus (Asteraceae) leaves are used to alleviate rheumatic pain, against fever and sunstroke with externally application in Turkish folk medicine.

Aim of the study

To evaluate the anti-inflammatory, antinociceptive and antioxidant activities of aqueous and ethanol extracts prepared from the leaves of Arctium minus ssp. minus.

Materials and methods

The ethanolic and aqueous extracts from the leaves of Arctium minus ssp. minus were evaluated in mice for anti-inflammatory activity using carrageenan-induced hind paw edema model and for antinociceptive activity using p-benzoquinone-induced abdominal contractions test. Moreover, the antioxidant power of the extracts has been determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and flow injection analysis-luminol chemiluminescence (FIA-CL). In addition, the total phenolic content in both extracts was determined with spectrophotometric method.

Results

Our results showed that only the ethanol extract exhibited a dose-dependent anti-inflammatory activity ranging between 11.1 and 23.6% at 200 mg/kg dose as well as displayed a significant antinociceptive activity without inducing any gastric damage. Although, both extracts were shown to possess significant DPPH radical-scavenging activity, that of aqueous extract was found to have more pronounced activity. In FIA-CL system, the ethanol extract was shown to possess a significant scavenger activity against H₂O₂ while the aqueous extract was much more potent antioxidant activity against HOCl-luminol CL than ethanol extract.

Conclusion

According to our results, it was concluded that Arctium minus ssp. minus contains potent natural antioxidants. In this study, in vivo experimental results have also supported the folk medicinal utilization of Arctium minus ssp. minus.     

Substantiation of the ethnopharmacological use of Conyza sumatrensis (Retz.) E.H.Walker in the treatment of malaria through in-vivo evaluation in Plasmodium berghei infected mice

Ethnopharmacological relevance

Scientific validation of ethnopharmacologically used plants and their utilization for therapeutic interventions can be a source of affordable treatment especially for neglected diseases in endemic areas. Conyza sumatrensis is a plant which finds its use in treating malaria like fevers but lacks proper scientific validation. Our study has tried to address this gap by authenticating its traditional use for the treatment of malaria.

Aim of the study

Evaluate the antimalarial activity of extracts derived from Conyza sumatrensis for its ethnopharmacological validation.

Materials and methods

Shade dried leaves were extracted with varying concentrations of ethanol and concentrated for bio-evaluation. Swiss albino mice infected with 1×10⁶ parasitized red blood cells, were orally administered with test extracts for 7 days in two sets of experiments. The first set was used to evaluate alcoholic, hydroalcoholic and aqueous extracts while the second set was used to evaluate the dose response of alcoholic extract ranging from 500–1600 mg/kg. Mean survival time, parasitaemia and haemoglobin levels were considered to interpret the antimalarial potential. Phytochemical analysis for the presence of flavonoids, alkaloids tannins, total phenolics, riboflavin and thiamine was also carried out.

Results

Among the three extracts administered at 1000 mg/kg, chemo suppression was significantly (p<0.001) observed in the alcoholic extract (62.59±12.52%) followed by hydroalcoholic (41.81±19.04%, p<0.01) and aqueous (32.04±19.04%, P<0.05) indicating that the active constituents leach out in ethanol. The dose response study involving the ethanol extract concluded the optimum dose to be 1000 mg/kg, as also evidenced by the haemoglobin levels.

Conclusion

The plant exhibits moderate antimalarial activity which can be further prospected for active fractions or pure molecules for adjunctive therapy.     

In vivo anti-inflammatory activities of Ocimum suave in mice

Ethnopharmacological relevance

Ocimum suave has been used in the Ethiopian traditional medicine to relieve pain, fever, inflammation and other disease conditions.

Aim of the study

The aim of the present study was to investigate the anti-inflammatory activities of the aqueous and ethanol leaf extracts and some fractions of Ocimum suave in mice.

Materials and methods

The crude extracts were screened for their anti-inflammatory activities on carrageenan-induced mouse paw edema at three dose levels. The butanol and aqueous fractions of the aqueous extract were also evaluated for their anti-inflammatory activities using carrageenan, histamine and serotonin-induced mouse paw edema at three dose levels. Normal saline and aspirin were employed as negative and positive control groups, respectively.

Results

Both ethanol and aqueous extracts significantly decreased carrageenan-induced inflammation at all the three doses used. However, greater paw edema inhibition was observed with the aqueous extract. The two fractions also showed significant reduction of inflammation against inflammatory models in which the aqueous residue exhibited the highest inhibition.

Conclusions

From the present findings, it can be concluded that the ethanol and aqueous leaf extracts as well as butanol and aqueous fractions of Ocimum suave have shown anti-inflammatory properties.     

Cholesterol-reducer,antioxidant and liver protective effects of Thymbra spicata L. var. spicata

Ethnopharmacological relevance

Thymbra spicata is a member of the Lamiaceae family; leaves of this plant have recently gained much popularity as a remedy to combat hypercholesterolaemia.

Aim of the study

To evaluate the antihypercholesterolaemic, antioxidant and anti-steatohepatitic activities of the diethyl ether (DEE), ethyl acetate (EtOAc) and remaining aqueous (RA) extracts from Thymbra spicata var. spicata in mice.

Materials and methods

In this study, diethyl ether, ethyl acetate and remaining aqueous extracts of Thymbra spicata L. var. spicata P.H.Davis (Lamiaceae) were evaluated for the effects on the plasma total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG) and glucose; blood malondialdehyde (MDA) and reduced glutathione (GSH); erythrocyte superoxide dismutase (SOD) and catalase activity (CAT) in mice fed with high-fat diet (HFD).

Results

The HFD induced an increase in plasma TC, TG, LDL, MDA concentrations compared to control group. However, administration of DEE with HFD reduced TC, LDL, TG and MDA concentrations, while increased HDL concentration, as well as GSH, SOD and CAT activities compared to HFD. The other extract from the plant was RA, which also showed a similar activity profile with DEE except CAT. On the other hand, administration of EtOAc extract with HFD decreased plasma TC, TG and MDA, while GSH concentration was increased. Histopathologically, best liver conditions were observed in DEE and lesser in RA extracts. Based on the results obtained in this investigation it is suggested that the DEE and partially RA extracts of Thymbra spicata var. spicata displayed significant antihypercholesterolaemic, antioxidant and anti-steatohepatitic activities. HPLC analysis of the DEE extract of Thymbra spicata var. spicata revealed the presence of carvacrol (44.13%).

Conclusion

The observed cholesterol-reducer, antioxidant and liver protective effects of the DEE and partially of RA extracts of Thymbra spicata which contain mainly carvacrol indicates that these extracts possess some potential medicinal value and explain their ethnomedical use.     

Anti-influenza virus effects of the aqueous extract from Mosla scabra

Ethnopharmacological relevance

Mosla scabra (Thunb.) C. Y. Wu is a broadly used species in the southeastern China as an antipyretic and antiviral drug for the treatment of colds, fever, inflammation and chronic bronchitis.

Aim of the study

To investigate the anti-influenza virus activities of the aqueous extract from Mosla scabra (AEMS), and to provide evidence for the implication of its immunomodulatory potential for the overall protective effect in lethal murine experimental influenza A infection.

Materials and methods

The anti-influenza virus activities of AEMS or ribavirin were evaluated in embryonated eggs and in a mouse infection model and the effects of AEMS on early immune responses during influenza virus infection were evaluated in a mouse infection model.

Results

At the concentration of 0.3–30.0 mg/ml, AEMS exhibited both preventive and therapeutical effect on embryonated egg. Oral administration of AEMS to mice infected with influenza virus A (IVA) was highly effective in preventing death, inhibiting pneumonia and reducing lung viral titers. It also significantly enhanced IFN-γ, IL-2, IL-4 and IL-5 cytokine-producing splenocytes, increased T-cell subsets like CD4⁺ and CD4⁺/CD8⁺, decreased levels of IL-6 after infection, and provided protective immunity. At a dosage of 4800 mg/kg, almost all treated mice survived, suggesting that AEMS is of low toxicity. However, ribavirin has weaker efficacy compared to AEMS.

Conclusions

These results showed, for the first time, while both AEMS and ribavirin appeared to have similar efficacy against IVA, AEMS playing a role as an immunomodulator and antiviral inhibitor during influenza virus infection, was considered to be less toxic and may warrant further evaluation as a possible agent for the treatment of influenza.     

Anticonvulsant effect of Marsilea quadrifolia Linn. on pentylenetetrazole induced seizure: a behavioral and EEG study in rats

Ethnopharmacological relevance

Marsilea quadrifolia Linn (MQ) extract has been used traditionally as sedative and antiepileptic drug in India.

Aim of this study

To investigate the anticonvulsive potential of MQ extracts by using behavior and electroencephalographic (EEG) analysis on pentylenetetrazole (PTZ) induced seizure model in rats.

Materials and methods

For anticonvulsant effect, 60 minutes after administration of MQ, behavior and EEG were analyzed during PTZ (60 mg/kg) induced seizures. Changes of EEG power, latency of onset of seizure, seizure severity score, and duration of epileptic seizure were determined.

Results

Both the water and ethanol extract of MQ increased the latency of seizure but also decreased duration of epileptic seizure and seizure severity score. This reduction of seizure severity was also observed in EEG recording and EEG power analysis. The effectiveness of MQ ethanol extract is better than MQ water extract.

Conclusion

Both water and ethanol extract of MQ were effective in reducing the severity of behavioral and EEG seizures induced by PTZ in rats. This study justifies the traditional use of this plant in epilepsy.     

Studies on the analgesic,anti-inflammatory and antipyretic effects of Parquetina nigrescens leaf extract

Ethnopharmacological relevance

Parquetina nigrescens is a shrub that is commonly used in different parts of West Africa for the treatment of several ailments which includes pain, fever and inflammatory conditions.

Aim of the study

The present study was designed to investigate the analgesic, anti-inflammatory and antipyretic effects of the aqueous extract of Parquetina nigrescens leaves in rats.

Materials and methods

Five groups were used for each study, groups 1 and 5 served as control (saline) and reference (indomethacine) respectively, while groups 2–4 received the extract (50–200 mg/kg) orally. Formalin paw licking and hot plate latency tests were used for analgesic studies. Carrageenan oedema, cotton pellet granuloma and formaldehyde arthritis models were used to quantify the anti-inflammatory activities while the brewer’s yeast was used for inducing pyrexia.

Results

The results of the analgesic study show that the extract produced significant (p < 0.05) analgesia in the hot plate and in the formalin tests. In the anti-inflammatory study, Parquetina nigrescens produced significant (p < 0.05) inhibition of the various types of inflammation. The extract also inhibited the pyrexia induced by brewer’s yeast.

Conclusion

The result justifies the traditional uses of Parquetina nigrescens for the treatment of fever, inflammatory and painful conditions.     

Effect of Vaccinium bracteatum Thunb. leaves extract on blood glucose and plasma lipid levels in streptozotocin-induced diabetic mice

Aim of the study

To investigate the hypoglycemic effects of Vaccinium bracteatum Thunb. leaves (VBTL) extract in streptozotocin-induced diabetic mice.

Materials and methods

After administration of VBTL extract for 4 weeks, the body weight, organ weight, blood glucose (BG), insulin and plasma lipid levels of streptozotocin-induced diabetic mice were measured.

Results

Body weights of diabetic mice treated with VBTL extract were partly recovered. The BG levels of AEG (diabetic mice treated with VBTL aqueous extract) were reduced to 91.52 and 85.82% at week 2 and week 4, respectively (P < 0.05), while those of EEG (diabetic mice treated with VBTL ethanolic extract) were reduced slightly (P > 0.05). The insulin levels of AEG and EEG were obviously higher (P < 0.05) than those of MC (diabetic mice in model control group). Comparing with MC, AEG and EEG had significantly lower (P < 0.05) TC or TG levels and similar HDL-cholesterol or LDL-cholesterol levels. In comparison with non-diabetic control mice, AEG had similar plasma lipid levels except higher LDL-cholesterol level, while EEG had higher TC, TG and LDL-cholesterol levels and lower HDL-cholesterol levels.

Conclusions

Both aqueous and ethanolic extract of VBTL possess a potential hypoglycemic effect in streptozotocin-induced diabetic mice.     

Extracts from Leonurus sibiricus L. increase insulin secretion and proliferation of rat INS-1E insulinoma cells

Ethnopharmacological relevance

Traditional Mongolian medicine (TMM) uses preparations from herbs as one form of medication for the treatment of a diversity of diseases including diabetes mellitus (DM). We evaluated the effect of extracts from the plant Leonurus sibiricus L. (LS), used in TMM to treat typical symptoms of type 2 DM, on insulin secretion, electrophysiological properties, intracellular calcium concentration and cell proliferation of INS-1E insulinoma cells under standard cell culture conditions (SCC; 11.1 mM glucose).

Materials and methods

Insulin secretion was measured by ELISA, electrical properties were assessed by whole cell patch clamping, intracellular calcium concentration (Ca_i) by Fluo-4 time lapse imaging, insulin receptor expression was verified by RT-PCR and cell proliferation assessed by CellTiter-Glo® cell viability assay.

Results

Insulin released from INS-1E cells into the culture medium over 24 h was significantly increased in presence of 500 mg/L aqueous LS extract (LS OWE) as well as methanolic LS extract (LS MeOH/H2O) but not in the presence of the butanol-soluble extract (LS MeOH/BuOH). Acute application of LS OWE resulted in a depolarization of the cell membrane potential paralleled by an initial increase and subsequent decline and silencing of action potential frequency, by KATP channel inhibition, persisting depolarization and an increase in Ca_i. The electrophysiological effects were comparable to those of 100 μM tolbutamide, which, however failed to elevate insulin secretion under SCC. Furthermore all LS extracts stimulated INS-1E cell proliferation.

Conclusions

The finding that extracts from Leonurus sibiricus L. enhance insulin secretion and/or foster cell proliferation may provide possible explanations for the underlying therapeutic principles in the empirical use of LS-containing formulations in DM and DM-related disorders as applied in TMM.     

The roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) inhibit atherogenic events: A study of the combination effects of the 2-herb formula

Ethnopharmacological relevance

The roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) are principle herbs of Chinese herbal formulae which have long been used to treat cardiovascular diseases.

Aim of study

The present study validated the anti-atherogenic effects of three extracts, Danshen alone (DE), Gegen alone (GE) as well as DGE and interpreted their combination effects statistically.

Materials and methods

The anti-atherogenic effects of the three extracts were studied in three assays with regards to inflammation, foam cell formation and vascular smooth muscle cell (vSMC) proliferation using lipopolysaccharide (LPS)-induced nitric oxide production model, macrophage foam cell formation model and platelet-derived growth factor (PDGF)-induced vSMC proliferation model, respectively. The combination effects of DGE were statistically analyzed using combination index (CI) and fixed-ratio experimental design.

Results

The anti-atherogenic effects of the three extracts including anti-inflammation, anti-foam cell formation and anti-vSMC proliferation were demonstrated in this study. Their combination effects in anti-inflammation, anti-foam cell formation and anti-vSMC proliferation were found to be synergistic, additive and antagonistic, respectively.

Conclusions

This study provided scientific support for the combination use of DGE on atherosclerosis and presented one of the first applications of statistical interpretations of the combination effects of the 2-herb formula.     

Ipomoea asarifolia neutralizes inflammation induced by Tityus serrulatus scorpion venom

Ethnopharmacological relevance

Envenoming caused by scorpion sting is a serious public health problem. In Brazil, 13,038 accidents caused by venomous animals have been reported. Of this total, 53% of the cases and 14 deaths were caused by scorpions. Furthermore, Tityus serrulatus (Buthidae) is the most dangerous scorpion due to the high toxicity of its venom. The treatment is the common supportive therapy and the serum therapy, but some people do not have access to both therapies and seek healing through the use of medical plants.

Aim of the study

This study evaluated the ability of the crude extract and fractions from the leaves of Ipomoea asarifolia in neutralizing the main biological effects caused by Tityus serrulatus envenoming in mice.

Materials and methods

BALB/c mice were pretreated (i.v.) with 100 μλ of aqueous extracts and fractions dichloromethane, ethyl acetate, and n-butanol (CH₂Cl₂, EtOAc, and n-BuOH, respectively) of Ipomoea asarifolia, rutin or saline. Then, the animals received 100 μλ (i.p.) of venom of Tityus serrulatus (0.8 mg/kg). After six hours, the peritoneal lavage was performed with PBS and the number cells were determined using a Neubauer chamber. The supernatants were collected for determination of cytokines, such as IL-6, IL-12, and IL-1β.

Results

The aqueous extract, fractions and rutin, at all doses, significantly reduced cell migration, which was endorsed by the reduction of the levels of certain cytokines.

Conclusion

This is the first study that demonstrated the potential effect of Ipomoea asarifolia against inflammation caused by Tityus serrulatus venom, suggesting that these extracts and/or their bioactive molecules, especially the flavonoid rutin, have potential use in the therapy of this envenomation.     

Pharmacological evaluation of sedative–hypnotic activity and gastro-intestinal toxicity of Rhizoma Paridis saponins

Ethnopharmacological relevance

Rhizoma Paridis saponins (RPS) have been well studied for antimicrobial, anti-hemorrhagic, and anticancer effects. However, scientific information on RPS regarding the toxic and neuropharmacological effects is limited. In this study, the acute oral toxicity, sedative–hypnotic activity and gastro-intestinal toxicity of RPS were investigated.

Materials and methods

The acute toxicity was carried out by administering single doses (800–5000 mg/kg) of RPS to adult mice. Rotarod test and sodium pentobarbital-induced hypnosis activity were used to evaluate the neuropharmacological effects on mice. Gastric emptying and intestinal transit were used to investigate the gastric–intestinal system effects.

Results

A single oral administration of RPS dose-dependently caused adverse effects on the general behavior and mortality rate of mice. LD₅₀ value of oral acute toxicity was 2182.4 mg/kg, with 95% confidence limit of 1718.4–2807.8 mg/kg. In the test of sleeping mice, RPS acted in synergy with sodium pentobarbital at doses 250 and 500 mg/kg while motor coordination was not influenced within 120 min after treatment with RPS. Regarding the gastric–intestinal toxicity, RPS (100, 250, and 500 mg/kg) significantly inhibited gastric emptying but did not affect the intestinal transit.

Conclusions

RPS, which is a hypotoxic anticancer drug, possesses the sedative–hypnotic activity and gastric stimulus side effect.     

Dual effects of crude extracts obtained from Petiveria alliacea L. (Phytolaccaceae) on experimental anxiety in mice

Aim of the study

Different preparations obtained from P. alliacea have been traditionally used in South America and Brazil for many medical conditions.To investigate the effects of fresh whole plant (WP) extract, aerial part (AP) extract, and root (R) extract obtained from Petiveria alliacea using the elevated plus maze (EPM) model of anxiety in mice. Total flavonoid content present in Petiveria alliacea extracts was also determined.

Materials and methods

WP, AP, or R (300–900 mg/kg) extracts were orally administered to mice 30 min before they were subjected to the EPM and open field test. Total flavonoid content present in the extracts was determined by spectrophotometry.

Results

The WP extract (300 and 900 mg/kg) caused anxiolytic-like effects, and the AP extract (300 mg/kg) induced anxiogenic-like effects in mice subjected to the EPM. No effect on anxiety-like behavior was observed with acute administration of the R extract. The content of flavonoids present in the AP extract (1.34%) was almost threefold higher than the flavonoid content present in the WP extract (0.52%).

Conclusions

Preparations using different fresh parts of Petiveria alliacea caused opposite effects on experimental anxiety in mice. However, predicting the extent to which flavonoid content present in Petiveria alliacea extracts differentially induces anxiolysis or anxiogenesis in mice was not possible. Further studies will be necessary to elucidate the effects of flavonoids or other substances present in Petiveria alliacea extracts on experimental anxiety.