Evaluation of the analgesic and antiedematogenic activities of Quassia amara bark extract

We evaluated the possible antiedematogenic, antinociceptive and/or sedative effects of four different extracts obtained from the bark of Quassia amara namely, 70% ethanol (70EtOH), 100% ethanol (100EtOH), dichloromethane (DCM) and hexane extracts (HEX). The oral administration (100, 250 and 500 mg/kg) of these extracts did not show significant effects in any experiment. However, when administered intraperitoneally, the HEX extract decreased the paw edema induced by carrageenan, showed antinociceptive effects on the hot-plate test and on acetic acid-induced writhing, and showed sedative effects on pentobarbital-induced sleep. Naloxone did not reverse the antinociceptive effect of this extract. In conclusion, although the mechanisms are uncertain, the results demonstrated that these effects are apparently related to sedative and muscle relaxant or psychomimetic activities of the HEX extract of the plant.     

Antiplasmodial activity of Setaria megaphylla

The antimalarial activity of an ethanol leaf extract of Setaria megaphylla was studied in vivo in mice infected with Plasmodium berghei berghei during early and established infections. Setaria megaphylla (100-300 mg/kg/day) exhibited a significant (p < 0.05) blood schizonticidal activity in 4-day early infection and in established infection with a significant (p < 0.05) mean survival time comparable to that of the standard drug, chloroquine, 5 mg/kg/day. The leaf extract possesses a promising antiplasmodial activity in vivo which can be exploited in malaria therapy.     

Simalikalactone D is responsible for the antimalarial properties of an Amazonian traditional remedy made with Quassia amara L. (Simaroubaceae)

French Guiana (North-East Amazonia) records high malaria incidence rates. The traditional antimalarial remedy most widespread there is a simple tea made out from Quassia amara L. leaves (Simaroubaceae). This herbal tea displays an excellent antimalarial activity both in vitro and in vivo. A known quassinoid, simalikalactone D (SkD), was identified as the active compound, with an IC(50) value of 10nM against FcB1 Plasmodium falciparum chloroquine resistant strain in vitro. Lastly, it inhibits 50% of Plasmodium yoelii yoelii rodent malaria parasite at 3.7 mg/kg/day in vivo by oral route. These findings confirm the traditional use of this herbal tea.     

The in vitro and in vivo antimalarial activity of Cardiospermum halicacabum L. and Momordica foetida Schumch. Et Thonn

Two plants Cardiospermum halicacabum L. and Momordica foetida Schumch. Et Thonn traditionally used to treat symptoms of malaria in parts of East and Central Africa were screened for in vitro and in vivo antimalarial activity. Using the nitro tetrazolium blue-based parasite lactate dehydrogenase assay as used by [Makler, M.T., Ries, J.M., Williams, J.A., Bancroft, J.E., Piper, R.C., Gibbins, B.L., Hinrichs, D.J., 1993. Parasite lactate dehydrogenase as an assay for Plasmodium falciparum drug sensitivity. American Journal of Tropical Medicine and Hygiene 48, 739-741], water extracts from the two plants were found to have weak in vitro antiplasmodial activity with 50% inhibitory concentrations (IC50s) greater than 28.00 microg/ml. In vivo studies of water extracts from the two plants showed that Momordica foetida given orally in the dose range 10, 100, 200 and 500 mg/kg twice daily prolonged survival of Plasmodium berghei (Anka) infected mice from 7.0+/-1.8 to 17.9+/-1.8 days. The water extract of Cardiospermum halicacabum L was toxic to mice, none surviving beyond day 4 of oral administration, with no evidence of protection against Plasmodium berghei malaria. The study emphasizes the discrepancy that might be found between in vitro and in vivo testing of plant-derived antimalarial extracts and the need to consider in vitro antiplasmodial data with this in mind. Further studies on Momordica foetida as a source of an antimalarial remedy are indicated on the basis of these results.     

Evaluation of French Guiana traditional antimalarial remedies

In order to evaluate the antimalarial potential of traditional remedies used in French Guiana, 35 remedies were prepared in their traditional form and screened for blood schizonticidal activity in vitro on Plasmodium falciparum chloroquine re4sistant strain (W2). Some of these extracts were screened in vivo against Plasmodium yoelii rodent malaria. Ferriprotoporphyrin inhibition test was also performed. Four remedies, widely used among the population as preventives, were able to inhibit more than 50% of the parasite growth in vivo at around 100 mg/kg: Irlbachia alata (Gentiananceae), Picrolemma pseudocoffea (Simaroubaceae), Quassia amara (Simaroubaceae), Tinospora crispa (Menispermaceae) and Zanthoxylum rhoifolium (Rutaceae). Five remedies displayed an IC50 in vitro < 10 microg/ml: Picrolemma pseudocoffea, Pseudoxandra cuspidata (Annonaceae) and Quassia amara leaves and stem, together with a multi-ingredient recipe. Two remedies were more active than a Cinchona preparation on the ferriprotoporphyrin inhibition test: Picrolemma pseudocoffea and Quassia amara. We also showed that a traditional preventive remedy, made from Geissospermum argenteum bark macerated in rum, was able to impair the intrahepatic cycle of the parasite. For the first time, traditional remedies from French Guiana have been directly tested on malarial pharmacological assays and some have been shown to be active.     

Quassia amara L. (Simaroubaceae) leaf tea: effect of the growing stage and desiccation status on the antimalarial activity of a traditional preparation

In French Guiana, Quassia amara L. (Simaroubaceae) leaf tea is a well-known widely used traditional antimalarial remedy. Impact of the vegetal sampling condition on in vivo and in vitro antimalarial activity was assessed. Traditional infusions were prepared with juvenile or mature leaves, both either fresh or dried. Results showed that growing stage and freshness of vegetal material exert a striking effect on antimalarial activity, both in vitro and in vivo. By far, leaf tea made from fresh juvenile (FJ) Quassia amara leaves was the most active. In vitro, active component (simalikalactone D) concentration correlates biological activities, although unexplained subtle variations were observed. In vivo, tea made with dried juvenile (DJ) leaves displays a peculiar behavior, meaning that some components may help simalikalactone D delivery or may be active in vivo only, therefore enhancing the expected curative effect of the traditional preparation.     

In vivo antimalarial activities of extracts from Amaranthus spinosus L. and Boerhaavia erecta L. in mice

Extracts obtained from two Burkinabe folk medicine plants, spiny amaranth (Amaranthus spinosus L., Amaranthaceae) and erect spiderling (Boerhaavia erecta L., Nyctagynaceae) were screened for antimalarial properties with the aim of testing the validity of their traditional uses. The plant extracts showed significant antimalarial activities in the 4-day suppressive antimalarial assay in mice inoculated with red blood cells parasitized with Plasmodium berghei berghei. We obtained values for ED(50) of 789 and 564 mg/kg for Amaranthus spinosus and Boerhaavia erecta extracts, respectively. Moreover the tested vegetal material showed only low toxicity (1,450 and 2,150 mg/kg as LD(50) for Amaranthus spinosus and Boerhaavia erecta, respectively).     

Antiplasmodial activity of Cylicodiscus gabunensis

The antimalarial activity of ethanolic stembark extract of Cylicodiscus gabunensis was studied in vivo in mice infected with Plasmodium berghei berghei during early and established infections as well as for repository activity. The LD(50) of the extract was determined to be 223.6 mg/kg, while doses of 250 mg/kg and above were found to be lethal to mice. Cylicodiscus gabunensis extract (20-60 mg/kg/day) exhibited a significant (P<0.05) blood schizontocidal activity in 4-day early infection, repository evaluation and in established infection with a significant mean survival time comparable to that of the standard drug, chloroquine, 5 mg/kg/day. The stembark extract possesses a promising antiplasmodial activity, which can be exploited in malaria therapy.     

Screening Azadirachta indica and Pisum sativum for possible antimalarial activities

Solvent-free extracts obtained from the leaves of Azadirachta indica and Pisum sativum were screened for antimalarial action using Plasmodium berghei in mice. Four days of oral dosing with 500 mg/kg and 125 mg/kg of the methanol extract of A. indica showed a parasite suppression which was statistically significant although all test animals died after 5 days, just 1 day longer than the untreated control group. A 50 mg/kg oral dose of the aqueous extract of P. sativum was found to have significant prophylactic activity by producing a parasite suppression of 31.9%.     

Antidiabetic activity of standardized extract of Quassia amara in nicotinamide-streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the efficacy of a standardized methanol extract of Quassia amara L. (Family: Simaroubaceae) in nicotinamide–streptozotocin‐induced diabetic rats. Non insulin dependent diabetes mellitus was induced by streptozotocin in rats pre‐treated with nicotinamide. Diabetic rats were treated with oral doses of Quassia amara extract (QaE; 100 and 200 mg/kg) or glibenclamide (10 mg/kg; as standard). QaE and glibenclamide were administered as a suspension in 0.3% carboxy methyl cellulose for 14 days. Control animals received an equal volume of vehicle. Blood samples were collected by retro‐orbital puncture on day 14, 1 h after last treatment. Plasma glucose, insulin and lipid parameters (total cholesterol, LDL‐C, HDL‐C and triglycerides) were measured using commercially available biochemical kits. The oral glucose tolerance test was performed to evaluate the effect of the extract on peripheral glucose utilization in normal rats. Both doses of QaE significantly (p < 0.01) reduced elevated fasting blood glucose levels in diabetic rats. In the oral glucose tolerance test, QaE treatment significantly increased (p < 0.05) the glucose tolerance compared with the vehicle. QaE and glibenclamide, effectively normalized dyslipidemia associated with streptozotocin‐induced diabetes. The findings of the present study indicate that Quassia amara extract may be potentially valuable in the treatment of diabetes and associated dyslipidemia. Copyright © 2011 John Wiley & Sons, Ltd.     

Screening for antimalarial activity in the genus Potomorphe

Ethanolic extracts (CEE) of leaves from Potomorphe umbellata and Potomorphe peltata, popularly said to have antimalarial capacity, were submitted to the 4-day suppressive test in Plasmodium berghei-infected mice. The CEE of P. umbellata administered either orally (250 and 1250 mg/kg) or subcutaneously (100 and 500 mg/kg) evidenced strong antimalarial activity, significantly reducing the levels of parasitaemia in a dose-dependent manner. On the other hand, the CEE of P. peltata was ineffective in lowering the parasitemic levels in malarious mice, which had been treated either orally (500 mg/kg) or subcutaneously (20, 100 and 500 mg/kg). An ethanol extract of the dry whole plant of P. peltata was also inactive.     

In vivo antiplasmodial activity of Bombax buonopozense root bark aqueous extract in mice infected by Plasmodium berghei

OBJECTIVE: To evaluate the in vivo antiplasmodial activity and the oral acute toxicity of the Bombax buonopozense root bark aqueous extract.METHODS: The in vivo antiplasmodial activity of the root bark aqueous extract of Bombax buonopozense against early and established rodent malaria infections in chloroquine sensitive Plasmodium berghei strain in mice was investigated, and oral acute toxicity of the aqueous root bark extract of Bombax buonopozense was also evaluated in mice.RESULTS: The findings of this study revealed significant(P 0.05) and dose dependent decrease in parasitaemia in the parasitized groups treated with varying doses of the extract(50-200 mg/kg p.o.) in both suppressive and curative tests. There was also significant decrease in parasitaemia density in the chloroquine treated group. The aqueous extract was found no toxicity in mice and the oral LD50 was determined to be greater than 5000 mg/kg.CONCLUSION: Bombax buonopozense root bark aqueous extract possesses potent antiplasmodial activity and may therefore, serve as potential sources of new antimalarial agents.     

In vivo Antimalarial Activity of a Labdane Diterpenoid from the Leaves of Otostegia integrifolia Benth

In Ethiopian traditional medicine, the leaves of Otostegia integrifolia Benth. are used for the treatment of several diseases including malaria. In an ongoing search for effective, safe and cheap antimalarial agents from plants, the 80% methanol leaf extract O. integrifolia was tested for its in vivo antimalarial activity, in a 4‐day suppressive assay against Plasmodium berghei. Activity‐guided fractionation of this extract which showed potent antiplasmodial activity resulted in the isolation of a labdane diterpenoid identified as otostegindiol. Otostegindiol displayed a significant (P < 0.001) antimalarial activity at doses of 25, 50 and 100 mg/kg with chemosuppression values of 50.13, 65.58 and 73.16%, respectively. Acute toxicity studies revealed that the crude extract possesses no toxicity in mice up to a maximum dose of 5000 mg/kg suggesting the relative safety of the plant when administered orally. The results of the present study indicate that otostegindiol is among the antimalarial principles in this medicinal plant, and further support claims for the traditional medicinal use of the plant for the treatment of malaria. Copyright © 2013 John Wiley & Sons, Ltd.     

Anti-ulcerogenic properties of Quassia amara L. (Simaroubaceae) standardized extracts in rodent models

Aim of the study

Quassia amara L. is commonly used in Costarican folk medicine. It has been used for the treatment of a broad range of gastrointestinal symptoms such as dyspepsia, gastritis and constipation. In this study, the gastroprotective activity of two standardized extracts of Quassia amara L., Lipro^® and Ligas^®, was evaluated.

Materials and methods

Anti-ulcerogenic properties were evaluated in female rats under acute ulcer-induction models (ethanol, indomethacin and hypotermic restraint). To get a deeper insight in the anti-ulcerogenic properties of the extracts, Ligas^® was evaluated in the Shay rat model. Five parameters were estimated with this model: gastric mucus barrier, non-protein sulfhydril groups (NPSG) in the gastric mucosa, and pH, total acidity and peptic activity of the gastric juice.

Results

Induction of ulcers by 95% ethanol (0.5 mL per os), indomethacin (100 mg/kg s.c.) and stress (2 h in hypothermic restraint) was inhibited significantly with administration of Lipro^® (p < 0.05), in a dosage range from 4.9 mg/kg/d to 48.9 mg/kg/d. Treatment was given for one week. The extract Ligas^® showed a significant augmentation of NPSG (p < 0.05) in a dosage range from 4.0 to 39.7 mg/kg. Ligas^® did not produce a significant change (p > 0.05) in the other indicators.

Conclusions

Quassia amara L. standardized extracts, Lipro^® and Ligas^®, showed an important anti-ulcerogenic effect in acute ulcer induction models. Their effect was related to an increase in gastric barrier mucus and non-protein sulfhydril groups.     

Evaluation of antiplasmodial activity of ethanolic seed extract of Picralima nitida

The in vivo antiplasmodial activity of the ethanol seed extract of Picralima nitida grown particularly for the leaf and seed in Niger Delta region of Nigeria was evaluated in Plasmodium berghei berghei infected mice. Picralima nitida (35-115 mg/kg day) exhibited significant (P<0.05) blood schizonticidal activity both in 4-day early infection test and in established infection with a considerable mean survival time though not comparable to that of the standard drug, chloroquine, 5 mg/kg day. The seed extract possesses significant (P<0.05) antiplasmodial activity which correlate with it reported in vitro activity.     

In vivo antimalarial activity and toxicological effects of methanolic extract of Cocos nucifera (Dwarf red variety) husk fibre

OBJECTIVE: Phytochemical constituents as well as antimalarial and toxicity potentials of the methanolic extract of the husk fi bre of Dwarf Red variety of Cocos nucifera were evaluated in this study.METHODS: The dried powdered husk fi bre was exhaustively extracted with hexane, ethyl acetate and methanol successively and the methanolic extract was screened for fl avonoids, phenolics, tannins, alkaloids, steroids, triterpenes, phlobatannins, anthraquinones and glycosides. A 4-day suppressive antimalarial test was carried out using Plasmodium berghei NK65-infected mice, to which the extract was administered at doses of 31.25, 62.5, 125, 250 and 500 mg/kg body weight(BW). Toxicity of the extract was evaluated in rats using selected hematological parameters and organ function indices after orally administering doses of 25, 50 and 100 mg/kg BW for 14 d.RESULTS: Phytochemical analysis revealed the presence of alkaloids, tannins, phenolics, saponins, glycosides, steroids and anthraquinones in the extract. Moreover, the extract reduced parasitemia by 39.2% and 45.8% at doses of 250 and 500 mg/kg BW respectively on day 8 post-inoculation. Various hematological parameters evaluated were not significantly altered(P0.05) at all doses of the extract, except red blood cell count which was signifi cantly elevated(P0.05) at 100 mg/kg BW. The extract significantly increased(P0.05) urea, creatinine, cholesterol, high-density lipoprotein-cholesterol and bilirubin concentrations in the serum as well as atherogenic index, while it reduced albumin concentration significantly(P0.05) at higher doses compared to the controls. Alanine aminotransferase activity was reduced in the liver and heart signifi cantly(P0.05) but was increased in the serum signifi cantly(P0.05) at higher doses of the extract compared to the controls.CONCLUSION: The results suggest that methanolic extract of the Dwarf red variety has partial antimalarial activity at higher doses, but is capable of impairing normal kidney and liver function as well as predisposing subjects to cardiovascular diseases.     

In vivo antimalarial activities of Enantia polycarpa stem bark against Plasmodium berghei berghei in mice

Ethnopharmacological relevance

Enantia polycarpa (PC) Engl. Et Diels (Annonaceae) is used in traditional medicine as an antimalarial remedy in Southern Nigeria.

Aim of the study

The antimalarial activities of ethanolic stem bark extracts of Enantia polycarpa was studied in vivo, in mice infected with Plasmodium berghei berghei.

Materials and methods

The ethanolic stem bark extract of Enantia polycarpa was administered at doses ranging from 200 to 600 mg/kg/day to Plasmodium berghei infected mice in both early and established models of antiplasmodial studies.

Results

The extract of Enantia polycarpa exhibited promising antimalarial activity against both early and established infections. At a dose of 600 mg/kg the extract achieved a 75.8% and 72% chemosuppression of parasitaemia in the study of acute and established infections, respectively. The extract also prolonged mean survival time of Plasmodium berghei infected mice during the study of established infection. The mean survival time of mice administered Enantia polycarpa extract at 600 mg/kg/day (27 days) was significantly longer than infected/untreated control (12 days). For the acute toxicity study the extract had an intraperitoneal LD₅₀ of 186 mg/kg but caused no mortality when administered orally at doses as high as 2,000 and 4,000 mg/kg.

Conclusions

Collectively, the results indicate that Enantia polycarpa is safe when administered orally and possesses promising antimalarial activity, thus supporting its use in traditional medicine for the treatment of malaria.     

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.     

Toxicity,antimicrobial and anthelmintic activities of Vernonia guineensis Benth. (Asteraceae) crude extracts

Ethnopharmacological relevance

This study examined the antibacterial, antifungal, and anthelmintic properties of extracts obtained from the plant Vernonia guineensis, a plant commonly used in traditional Cameroonian medicine.

Materials and methods

For in vitro studies, 10 g of leaf and tuber powder from V. guineensis was extracted separately using dichloromethane, methanol and distilled water. The extracts were dried in vacuo and used for antimicrobial and anthelmintic activity studies. In the antimicrobial assay, extracts were tested against bacterial and fungal organisms including; Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, Aspergillus fumigatus, Candida albicans and Trichophyton mentagrophytes. In the anthelmintic assay, larval and adult stages of the hookworm Ancylostoma ceylanicum and the mouse nematode Trichuris muris were used. For the acute toxicity test, male and female rats of 150–200 g body weight were used in the experiment. The aqueous extract of V. guineensis tubers was administered in 4 doses of 500, 1000, 2000 and 4000 mg/kg per group (n=6), respectively, and the control group received distilled water.

Results

The crude extracts exhibited weak antibacterial and antifungal activity except for the dichloromethane extract, which showed moderate activity against A. fumigatus (MIC=200 μg/ml). In the anthelmintic assay, the organic extracts of the tubers had 100% killing efficacy against T. muris at 2 mg/ml in 48 h, while the aqueous extract showed no activity. The organic leaf extracts demonstrated potent activity killing 100% of the adult worms 1 mg/ml in 24 h. The aqueous leaf extract was active at 2 mg/ml in 72 h, killing 100% of the adult worms. In the acute toxicity test, V. guineensis did not produce any toxic signs or death at the maximum concentration of 4000 mg/kg.

Conclusion

Crude extracts from V. guineensis possess anthelmintic activity against T. muris with only weak antibiotic activity. Acute administration of aqueous extract from V. guineensis tubers did not produce toxic effects in rats. The absence of acute toxicity at the highest concentration tested indicates that the tea decoction from V. guineensis extract is safe at concentrations ≤4000 mg/kg.     

Evaluation of the antidiarrhoeal activity of Byrsocarpus coccineus

Based on its use in traditional African medicine, the antidiarrhoeal activity of the aqueous leaf extract of Byrsocarpus coccineus, Connaraceae, was evaluated on normal and castor oil-induced intestinal transit, castor oil-induced diarrhoea, enteropooling and gastric emptying. The extract (50, 100, 200 and 400 mg/kg, p.o.) produced a significant (P<0.05) dose dependent decrease in propulsion in the castor oil-induced intestinal transit in mice. The mean peristaltic index (%) for these doses of extract, control (distilled water; 10 ml/kg, p.o.) and morphine (10 mg/kg, s.c.) were 55.27+/-1.86, 53.12+/-3.73, 38.60+/-3.79, 30.25+/-1.27, 89.33+/-5.62 and 20.29+/-3.38, respectively. The effect of the extract at the highest dose was significantly (P<0.05) lower than that of the standard drug. This effect was antagonised by yohimbine (1 mg/kg, s.c.) but not by isosorbide dinitrate (IDN, 150 mg/kg, p.o.). At 200 mg/kg, the extract produced a significant decrease in propulsion in normal intestinal transit. In a dose dependent manner, it delayed the onset of diarrhoea, produced a significant decrease in the frequency of defaecation, severity of diarrhoea and protected the mice treated with castor oil. Mean diarrhoea scores were 30.83+/-1.72, 22.40+/-1.71, 21.43+/-1.32, 13.80+/-0.33, 18.00+/-3.94 and 7.67+/-2.41 for control, extract (50, 100, 200 and 400 mg/kg) and morphine, respectively. This effect was not antagonized by IDN. The extract (400 mg/kg) significantly decreased the volume (ml) of intestinal fluid secretion induced by castor oil (0.60+/-0.23) compared with 1.27+/-0.12 for control. However, there was no significant effect on gastric emptying. The results obtained suggest that Byrsocarpus coccineus possesses antidiarrhoeal activity due to its inhibitory effect on gastrointestinal propulsion, mediated through alpha(2) adrenoceptors, and also inhibition of fluid secretion. Preliminary phytochemical analysis revealed the presence of alkaloids, tannins, saponins, reducing sugars, glycosides and anthraquinones.