Antiplasmodial activity of Homalium letestui

The in vivo antiplasmodial activity of the ethanol root extract of Homalium letestui used as a malaria remedy in Southern Nigeria was evaluated in Plasmodium berghei berghei infected mice. Homalium letestui root extract (500-1000 mg/kg/day) exhibited significant (p < 0.05) blood schizontocidal activities both in a 4-day early infection test and in an established infection with a considerable mean survival time comparable to that of the standard drug, chloroquine, 5 mg/kg/day. The root extract possesses significant (p < 0.05) antiplasmodial activity, which can be exploited in malaria therapy.     

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.     

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.     

Antimalaria activity of ethanolic extract of Tetrapleura tetraptera fruit

The in vivo antiplasmodial activity of the ethanol fruit extract of Tetrapleura tetraptera used as spice and in the treatment of various ailment in Niger Delta region of Nigeria was evaluated in Plasmodium berghei infected mice. Tetrapleura tetraptera (300-900 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 comparable to that of the standard drug, chloroquine, 5 mg/kg day. The fruit extract possesses significant (P < 0.05) antiplasmodial activity with may have contributed to the immune status of the Nigerians against malaria in addition to its nutritive value.     

In vivo antimalarial activities of Quassia amara and Quassia undulata plant extracts in mice

Extracts obtained from two Nigerian Simaroubaceae plants, Quassia amara L. and Quassia undulata (Giull and Perr) D. Dietr were screened for antimalarial properties using a total of six extracts. The plant extracts showed significant antimalarial activities in the 4 day suppressive in vivo antimalarial assay in mice inoculated with red blood cells parasitized with Plasmodium berghei berghei. Plant extracts were studied at 100 mg and 200 mg per kg body weight mouse per day, respectively. At a concentration of 100 mg/kg of mouse, Q. amara leaf hexane extract had the highest suppressive activity with a parasite density of 0.16 +/- 0.001%. Q. amara leaf methanol extract had an outstanding activity; of 0.05 +/- 0.03% at 200 mg/kg. Chloroquine (10 mg/kg, positive control) had a suppressive activity of 0.34 +/- 0.02 in the same assay on day 4.     

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.     

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.     

Effects of American ginseng berry extract on blood glucose levels in ob/ob mice

In this study, we evaluated antihyperglycemic effects of American ginseng berry extract in diabetic ob/ob mice. Animals received daily intraperitoneal (IP) injections of the extract 150 mg/kg for 12 days. On days 5 and 12, the extract-treated ob/ob mice had significantly lower fasting blood glucose levels compared to day 0 (both p < 0.05). Glucose tolerance improved significantly, which was shown by overall glucose excursion, calculated as area under the curve (AUC) during the two-hour IP glucose tolerance test. The AUC decreased by 31.8% on day 12 compared to day 0 (p < 0.01). In addition, after 12 days of the berry extract treatment, a significant reduction in body weight (p < 0.01 compared to day 0) and a significant increase in body temperature (p < 0.01 compared to day 0) was noticeable. Our results support in vivo antihyperglycemic and antiobese activity of American ginseng berry extract that may prove to be of clinical importance in the prevention and treatment of Type 2 diabetes.     

Antimalarial activities of Tithonia diversifolia (Asteraceae) and Crossopteryx febrifuga (Rubiaceae) on mice in vivo

Ethanolic extracts of the aerial part of Tithonia diversifolia and the stem bark of Crossopteryx febrifuga were investigated against early, residual (repository) and established malaria infections in vivo using Swiss albino mice at a dose range of 50-400 mg/kg per day. Chloroquine at 5 mg/kg per day was used as the positive control for the early and established infections while Pyrimethamine at 1.2 3/kg per day was used as the positive control for the residual infection test. Dose dependent chemo suppressive activities were obtained at the different levels of the infection tested. Tithonia diversifolia and Crossopteryx febrifuga gave some level of suppression of parasitaemia in the early and established infection stages. Tithonia diversifolia was active at 200 mg/kg per day in the repository test. The mean survival period of the mice treated with the extract in the established infection test was low, a possible indication of toxicity as a result of sub chronic administration of the extract. Crossopteryx febrifuga was inactive in the repository test. Beside the above limitations, the suppression of parasitaemia by the extracts at the highest dose was similar to chloroquine and pyrimathamine.     

Combination effects of chloroquine with the febrifugine and isofebrifugine mixture against a blood-induced infection with chloroquine-resistant Plasmodium berghei NK65 in ICR mice

The combination effects of chloroquine with a mixture of febrifugine and isofebrifugine were evaluated against a blood-induced infection with chloroquine-resistant P. berghei NK65 in ICR mice. Mice in the untreated control showed a progressively increasing parasitemia leading to mouse death. A two-day dosage of 20 mg base/kg of chloroquine alone showed little effect against P. berghei NK65 infection, and all mice died from day 13 to 14 with an increasing parasitemia. A four-day dosage of 1 mg/kg of the febrifugine and isofebrifugine mixture alone showed a little antimalarial activity, but all mice died from day 19 to 27 with an increasing parasitemia. On the other hand, mice treated with chloroquine plus alkaloids survived during the experiment. All mice treated with chloroquine alone or the alkaloid mixture alone showed low parasitemia levels during a drug administration and following a few days, but then malaria parasites increased in the bloodstream of the treated mice until death. On the other hand, malaria parasites in the mice given chloroquine plus alkaloids decreased on day 6 and then were not detected by a microscopic examination during observation period.     

Anticonvulsant, analgesic and antipyretic activities of Taxus wallichiana Zucc

Taxus wallichiana Zucc. (Himalayan Yew) is often used in northern areas of Pakistan for the treatment of pyrexia, acute pains and epilepsy. We have investigated certain pharmacological activities of the methanol leaf extract against convulsion, nociception and pyrexia induced in rodents. The aim was to justify and explore its folk uses in these pathological conditions, on scientific basis. The studies were carried out using acetic acid-induced nociception and pentylenetetrazole-induced convulsions in mice, while formalin test and yeast-induced pyrexia in rats. Significant analgesic (67.77 and 74.29%) effect was found in acetic acid-induced model at doses of 100 and 200mg/kg, i.p. respectively. Crude extract exhibited significant (P<0.05) inhibition of the formalin noxious stimulation on both early and late phases of pain by the extracts (100 and 200mg/kg doses). In case of yeast-induced pyrexia model, 200mg/kg dose showed very significant (P<0.01) inhibition while 50 and 100mg/kg dose caused a significant (P<0.05) inhibition. Plant extract has controlled the pentylenetetrazole-induced convulsions in mice. 100 and 200mg/kg i.p doses of the extract significantly (P<0.05) inhibited the mioclonus and clonus while inhibition of tonus and hind limb tonic extension (HLTE) was highly significant (P<0.01). The anticonvulsant activity of this plant has been reported for the first time throughout the whole genus. The observed pharmacological activities provide the scientific basis for the folkloric use of the plant in treating epilepsy, pyrexia and acute pain.     

Effect of Khaya grandifoliola extract on Plasmodium berghei berghei in mice

Khaya grandifoliola stem bark extract was tested for antimalarial action against Plasmodium berghei berghei in mice. The schizontocidal activity of the extract was assessed on early and established infections using chloroquine as a standard drug. The repository activity was also investigated and pyrimethamine was used as the standard. In the early infection test (like the chloroquine group), K. grandifoliola extract was effective in suppressing the malaria infection. However, on the established infection, the extract failed to effectively suppress the infection. The extract also demonstrated residual activity.     

Curry leaf (Murraya koenigii Spreng.) reduces blood cholesterol and glucose levels in ob/ob mice

We observed that curry leaf (Murraya koenigii) extract possesses the property to decrease blood cholesterol and blood glucose levels in diabetic ob/ob mice. Mice received daily intraperitoneal injections of 80 mg/kg curry leaf extract for 10 consecutive days. The extract significantly decreased blood cholesterol level from 277.6 +/- 16.6 mg/d (day 0) to 182.0 +/- 15.3 mg/d (day 10, p < 0.01 compared with the change in vehicle group). The extract also significantly decreased blood glucose level from 387.0 +/- 15.6 mg/dl (day 0) to 214.0 +/- 26.6 mg/dl (day 10, p < 0.01). In addition, body weight was reduced after extract treatment. Our data suggest that curry leaf may be proved to be of clinical importance in improving the management of high cholesterol level and type 2 diabetes.     

Antimalarial 4-phenylcoumarins from the stem bark of Hintonia latiflora

The EtOAc extract of the stem bark of Hintonia latiflora showed the suppression of total parasitemia and the chemosuppression of schizont numbers, when tested in vivo against Plasmodium berghei infection in mice. Bioassay-directed fractionation of the EtOAc extract, using the in vitro 16 h and the in vivo 4-day suppression tests on P. berghei schizont numbers, led to the isolation of the new compound 5-O-beta-D-glucopyranosyl-7,4'-dimethoxy-3'-hydroxy-4-phenylcoumarin (1), along with the known 5-O-beta-D-glucopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin (2). The structure of compound 1 was established on the basis of spectroscopic data interpretation. Compounds 1 and 2 suppressed the development of P. berghei schizonts in vitro with IC50 values of 24.7 and 25.9 microM, respectively. Compound 2 suppressed the development of schizonts at the dose of 40 mg/kg by 70.8% in the in vivo assay.     

In vivo antiplasmodial potential of three herbal methanolic extracts in mice infected with Plasmodium berghei NK65

Objective: The present study deals with the investigation of antiplasmodial potential of leaf methanolic extract of Aegle marmelos, Aristolochia indica and Cassia auriculata against Plasmodium berghei(NK65)infected mice.Methods: The chloroquine-sensitive parasites P. berghei(1 × 106) were inoculated into Swiss albino mice intraperitoneally. The methanol extracts of three herbal plants were orally administered in P. berghei infected mice which were further assessed using the four-day suppressive test at different doses of 150, 300 and 600 mg/kg per day. Chloroquine(CQ) was used as the standard drug with of 1.25, 2.5 and 5 mg/kg concentrations and was orally administered.Results: The leaves of A. marmelos, A. indica, and C. auriculata were found to suppress P. berghei parasitaemia in Swiss albino mice by(67.0 ± 4.02)%,(72.0 ± 8.44)% and(52.7 ± 2.06)% at 600 mg/kg/d with ED50 values of 284.73, 233.77 and 562.48 mg/kg, respectively. These herbal plants increased the mean survival time of infected mice and prevented body weight loss. GC-MS analysis revealed the presence of hentriacontan-16-one(C31 H62 O) in A. indica extract. The histopathology study showed non-toxic to kidney and liver at 600 mg/kg/body weight.Conclusions: Overall results revealed that herbal plants may be active in the development of novel and cheap antimalarial compounds.     

The antidiarrhoeal activity of Alchornea cordifolia leaf extract

Diarrhoea is a public health problem in developing countries. It is therefore important and useful to identify plants with antidiarrhoeal activity. Alchornea cordifolia is quoted by many traditional healers as a plant with this activity. The antidiarrhoeal activity of its leaf extract was investigated against castor oil induced diarrhoea in mice, using morphine as the standard reference drug. A significant (p < 0.01) dose related (100 mg/kg, 200 mg/kg, 400 mg/kg, 800 mg/kg) antidiarrhoeal activity of A. cordifolia leaf ethanol extract was observed with 800 mg/kg extract being the most effective. It delayed mouse intestinal transit accelerated by castor oil, inhibited the production of diarrhoeal faeces and modified the fluid and electrolyte transport across the colonic mucosa when administered intraluminally. Phytochemical screening revealed the presence of tannins and flavonoids which may account for the increased colonic water and electrolyte reabsorption, a mechanism suggested for the antidiarrhoeal activity of A. cordifolia.     

Antinociceptive, anti-inflammatory and antidiabetic effects of Bryophyllum pinnatum (Crassulaceae) leaf aqueous extract

In order to scientifically appraise some of the ethnomedical uses of Bryophyllum pinnatum leaves, the present study was undertaken to investigate the antinociceptive, anti-inflammatory and antidiabetic properties of the plant's leaf aqueous extract in experimental animal models. The antinociceptive effect of the herb's leaf extract was evaluated by the 'hot-plate' and 'acetic acid' test models of pain in mice. The anti-inflammatory and antidiabetic effects of the plant's extract were investigated in rats, using fresh egg albumin-induced pedal (paw) oedema, and streptozotocin (STZ)-induced diabetes mellitus. Diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used respectively as reference drugs for comparison. Bryophyllum pinnatum leaf aqueous extract (BPE, 25-800 mg/kg i.p.) produced significant (P<0.05-0.001) antinociceptive effects against thermally- and chemically-induced nociceptive pain stimuli in mice. The plant extract (BPE, 25-800 mg/kg p.o. or i.p.) also significantly (P<0.05-0.001) inhibited fresh egg albumin-induced acute inflammation and caused significant (P<0.05-0.001) hypoglycaemia in rats. The results of this experimental animal study suggest that Bryophyllum pinnatum leaf aqueous extract possesses antinociceptive, anti-inflammatory and hypoglycaemic properties. The different flavonoids, polyphenols, triterpenoids and other chemical constituents of the herb are speculated to account for the observed antinociceptive, anti-inflammatory and antidiabetic properties of the plant.     

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%.     

Antimalarial Activity of Alkaloids from Pogonopus tubulosus

The antimalarial activity of the Bolivian medicinal plant Pogonopus tubulosus (D.C.) Schumann was evaluated by in vitro testing on trophozoite stages of resistant and sensitive strains of Plasmodium falciparum and by in vivo tests on P. berghei and P. vinckei petteri in mice. The bark of this medicinal plant yielded three alkaloids: tubulosine, psychotrine, cephaeline. Tubulosine showed an interesting activity in vitro with an IC₅₀ of 0.006 μg/mL against the sensitive strain of P. falciparum and an IC₅₀ of 0.011 μg/mL against the resistant strain of P. falciparum . This compound had good in vivo antimalarial activity with an ED₅₀ of 0.05 mg/kg/day on P. vinckei petteri strain and an ED₅₀ of 0.45 mg/kg/day on P. berghei.