Antimalarial and antiplasmodial activity of husk extract and fractions of Zea mays.

CONTEXT: Zea mays L. (Poacae) husk decoctions are traditionally used in the treatment of malaria by various tribes in Nigeria. OBJECTIVE: To assess the antimalarial and antiplasmodial potentials of the husk extract and fractions on malaria parasites using in vivo and in vitro models. MATERIALS AND METHODS: The ethanol husk extract and fractions (187-748 mg/kg, p.o.) of Zea mays were investigated for antimalarial activity against Plasmodium berghei using rodent (mice) malaria models and in vitro activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using the SRBR green assay method. Median lethal dose and cytotoxic activities against HeLa and HEKS cells were also carried out. The GCMS analysis of the most active fraction was carried out. RESULTS: The husk extract (187-748 mg/kg, p.o.) with LD50 of 1874.83 mg/kg was found to exert significant (p < 0.05-0.001) antimalarial activity against P. berghei infection in suppressive, prophylactive and curative tests. The crude extract and fractions also exerted prominent activity against both chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC50 values of 9.31 ± 0.46 µg/mL (Pf 3D7) and 3.69 ± 0.66 µg/mL (Pf INDO). The crude extract and fractions were not cytotoxic to the two cell lines tested with IC50 values of >100 µg/mL against both HeLa and HEKS cell lines. DISCUSSION AND CONCLUSION: These results suggest that the husk extract/fractions of Zea mays possesses antimalarial and antiplasmodial activities and these justify its use in ethnomedicine to treat malaria infections.

Antimalarial, antiplasmodial and analgesic activities of root extract of Alchornea laxiflora.

CONTEXT: Alchornea laxiflora (Benth.) Pax. & Hoffman (Euphorbiaceae) root decoctions are traditionally used in the treatment of malaria and pain in Nigeria. OBJECTIVE: To assess the antimalarial, antiplasmodial and analgesic potentials of root extract and fractions against malarial infections and chemically-induced pains. MATERIAL AND METHODS: The root extract and fractions of Alchornea laxiflora were investigated for antimalarial activity against Plasmodium berghei infection in mice, antiplasmodial activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method and analgesic activity against experimentally-induced pain models. Acute toxicity study of the extract, cytotoxic activity against HeLa cells and GCMS analysis of the active fraction were carried out. RESULTS: The root extract (75-225 mg/kg, p.o.) with LD50 of 748.33 mg/kg exerted significant (p < 0.05-0.001) antimalarial activity against P. berghei infection in suppressive, prophylactive and curative tests. The root extract and fractions also exerted moderate activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC50 value of 38.44 ± 0.89 µg/mL (Pf 3D7) and 40.17 ± 0.78 µg/mL (Pf INDO). The crude extract was not cytotoxic to HeLa cells with LC50 value >100 µg/mL. The crude extract and ethyl acetate fraction exerted significant (p < 0.05-0.001) analgesic activity in all pain models used. DISCUSSION AND CONCLUSIONS: These results suggest that the root extract/fractions of A. laxiflora possess antimalarial, antiplasmodial and analgesic potentials and these justify its use in ethnomedicine to treat malaria and pain.

Anti-inflammatory and antinociceptive activities of Homalium letestui.

CONTEXT: Homalium letestui Pellegr (Flacourtiaceae) is used in various decoctions traditionally by the Ibibios of the Niger Delta of Nigeria to treat stomach ulcer, malaria and other inflammatory diseases, as well as an aphrodisiac. OBJECTIVE: To investigate the anti-inflammatory and antinociceptive activities of the stem extract of the plant. MATERIALS AND METHODS: The ethanol stem extract (500, 750, 1000 mg/kg, i.p.) of H. letestui was investigated for anti-inflammatory activity using carrageenan, egg albumin-induced and xylene-induced ear edema models and analgesic activity using acetic acid-induced writhing, formalin-induced paw licking and thermal-induced pain models. The ethanol extract was administered to the animals orally, 30 min to 1 h depending on the model, before induction of inflammation/pain. The LD50 was also determined. GC-MS analysis of dichloromethane fraction was carried out. RESULTS: The extract caused a significant (p < 0.05-0.001) reduction of inflammation induced by carrageenan (8.3-70.0%), egg albumin (10.0-71.42%) and xylene (39.39-84.84%). The extract also reduced significantly (p < 0.05-0.001) pain induced by acetic acid (44.22-73.65%), formalin (55.89-79.21%) and hot plate (93.0-214.5%). The LD50 was determined to be 4.38 ± 35.72 g/kg. DISCUSSION AND CONCLUSION: The results of this study suggest that the ethanol stem extract of H. letestui possesses anti-inflammatory and analgesic properties which may in part be mediated through the chemical constituents of the plant as revealed by the GC-MS.

Antioxidative burst and hepatoprotective effects of ethanol root extract of Hippocratea africana against paracetamol-induced liver injury.

CONTEXT: Hippocratea africana (Willd.) Loes. ex Engl. (Celastraceae) root is used traditionally as an antipoison or antidote to treat liver diseases. OBJECTIVE: To evaluate antioxidative burst and hepatoprotective potentials of H. africana against paracetamol-induced liver injury in rats. MATERIALS AND METHOD: Antioxidative burst activity of the extract (1-100 µg/ml) in whole blood, neutrophils and macrophages was investigated using a luminol/lucigenin-based chemiluminescence assay. The hepatoprotective effect of the extract (200-600 mg/kg) was evaluated by the assay of liver function parameters, antioxidant enzymes and histopathological studies of the liver. GC-MS analyses of hexane and dichloromethane fractions were also carried out. RESULTS AND DISCUSSION: The root extract/fractions exerted pronounced inhibition of oxidative burst activity in whole blood, neutrophils (intracellular and extracellular) and macrophages (3.04-99.70%). The administration of the root extract caused significant (p < 0.05-0.001) reduction of high levels of liver enzymes (AST, ALT and ALP), total cholesterol, direct and total bilirubin as well as elevation of serum levels of total protein, albumin and antioxidant enzymes (SOD, CAT, GPx and GSH). Histology of the liver sections of extract and silymarin-treated animals showed reductions in the pathological features compared to the paracetamol-treated animals. The chemical pathological changes were consistent with histopathological observations suggesting a marked hepatoprotective effect of the root extract of H. africana. The GC-MS analysis revealed some pharmacologically active compounds. CONCLUSION: The results show that the root extract of H. africana has hepatoprotective potential probably due to its antioxidative burst activity.

In vivo antihyperglycaemic and antihyperlipidemic activities and chemical constituents of Solanum anomalum.

Solanum anomalum is a plant used ethnomedically for the treatment of diabetes. The study was aimed to validate ethnomedical claims in rat model and identify the likely antidiabetic compounds. Leaf extract (70-210 mg/kg/day) and fractions (140 mg/kg/day) of S. anomalum were evaluated in hyperglycaemic rats induced using alloxan for effects on blood glucose, lipids and pancreas histology. Phytochemical characterisation of isolated compounds and their identification were performed using mass spectrometry and NMR spectroscopy. Bioinformatics tool was used to predict the possible protein targets of the identified bioactive compounds. The leaf extract/fractions on administration to diabetic rats caused significant lowering of fasting blood glucose of the diabetic rats during single dose study and on repeated administration of the extract. The hydroethanolic leaf extracts also enhanced glucose utilization capacity of the diabetic rats and caused significant lowering of glycosylated hemoglobin levels and elevation of insulin levels in the serum. Furthermore, triglycerides, LDL-cholesterol, and VLDL-cholesterol levels were lowered significantly, while HDL-cholesterol levels were also elevated in the treated diabetic rats. There was absence or few pathological signs in the treated hyperglycaemic rat pancreas compared to that present in the pancreas of control group. Diosgenin, 25(R)-diosgenin-3-O-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranoside, uracil, thymine, 1-octacosanol, and octacosane were isolated and identified. Protein phosphatases along with secreted proteins are predicted to be the major targets of diosgenin and the diosgenin glycoside. These results suggest that the leaf extract/fractions of S. anomalum possess antidiabetic and antihyperlipidemic properties, offer protection to the pancreas and stimulate insulin secretion, which can be attributable to the activities of its phytochemical constituents.

In vitro and in vivo antimalarial activity and chemical profiling of sugarcane leaves.

Saccharum officinarum Linn. (sugarcane, Family-Poaceae) is employed in Ibibio traditional medicine for the treatment of various infections and diseases such as malaria. We This study aims to assess the antiplasmodial effect of the leaf extract and fractions on human malaria parasite (Plasmodium falciparum) in vitro, and rodent malaria parasite (P. berghei) in vivo, and analyse the bioactive components of the active fraction(s). The leaf extract and fractions of S. officinarum were prepared and their growth inhibitory effects tested against the chloroquine resistant P. falciparum strain (Dd2) and P. berghei infection in mice. An acute toxicity of the extract was determined. A combination of gas chromatography and liquid chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy was applied for metabolites profiling of crude extract and active fractions. The leaf extract and fractions demonstrated moderate activity against P. falciparum with the dichloromethane fraction producing the most potent activity (EC50 = 15.4 µg/mL). The leaf extract (170-510 mg/kg, p.o., LD50 = 1732 mg/kg) and fractions demonstrated significant (p < 0.05-0.001) effect on P. berghei infection in prophylactic  tests as well as in established infection with n-butanol fractions producing the highest effect. An unusual sulphur-containing compound, dilaurylthiodipropionate, fatty acids, phenolic acids, flavonoid and flavonoid glycoside were identified in the active fractions. These results give credence to the use of sugarcane leaves as malarial remedy locally by confirming the in vitro and in vivo antiplasmodial potential of leaf extract/fractions of S. officinarum.

In vivo antimalarial activities of ethanolic crude extracts and fractions of leaf and root of Carpolobia lutea.

Carpolobia lutea (leaves and root) is used traditionally as malarial remedy by the Ibibios of Niger Delta of Nigeria and Benin. This study was aimed to investigate the antiplasmodial potentials of the crude leaf and root extracts of this plant as well as their fractions in vivo in Plasmodium berghei berghei-infected mice to give scientific proof to the ethnobotanical claims and correlate with the reported in vivo activity. The ethanolic extracts of Carpolobia lutea leaf (245-735 mg/kg/day) and root (7-21 mg/kg/day) were screened for blood plasmocidal activity against chloroquine-sensitive Plasmodium berghei in mice. The antimalarial activity in 4-day and curative tests was evaluated. Carpolobia lutea leaf extract (245-735 mg/kg/day) and fractions exhibited significant (p<0.05-0.01) antiplasmodial activity both in 4-day early infection test and in established infection with a considerable mean survival time which was incomparable to that the standard drug, chloroquine (5 mg/kg/day). The root extract (7-21 mg/kg/day) and fractions also demonstrated a promising blood schizontocidal activity in early and established infections. These plant extracts and fractions possess considerable antiplasmodial activities which justify their use in ethnomedicine and can be exploited in the control of malaria.

Isolation and characterization of bioactive xanthones from Hippocratea africana (Willd.)Loes.ex Engl. (Celastraceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Hippocratea africana root is used in African folk medicine for the treatment of several ailments, including pain and inflammation. AIM OF THE STUDY: To isolate anti-inflammatory and analgesic compounds from the roots of H. africana, with accompanying antioxidant potentials. MATERIALS AND METHODS: Dichloromethane, ethyl acetate, and aqueous fractions of H. africana roots, and isolated compounds from the bioactive ethyl acetate fraction were evaluated for anti-inflammatory and analgesic activities using the xylene induced oedema in mice and thermal induced pain models, respectively. The antioxidant potentials of isolated compounds were tested in 2,2-diphenyl-1-picryhydrazyl radical and ferric reducing antioxidant power assays. Structures were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR experiments, ionization mass spectrometry, and comparison with literature data. RESULTS: Isoathyriol (1,3,7-trihydroxy-6-methoxyxanthone) and norathyriol (1,3,6,7-tetrahydroxyxanthone) were isolated from the potent anti-inflammatory and analgesic ethyl acetate fraction of H. africana roots. Isoathyriol and norathyriol demonstrated good anti-inflammatory, analgesic, and antioxidant properties compared with the standards used in each assay. CONCLUSIONS: This study substantiates the use of H. africana root extract in the alleviation of inflammation and pain, and reports the characterization of secondary metabolites in H. africana and for the first time the presence of xanthones in Hippocratea genus.

Antimicrobial activity of root extract and crude fractions of Croton zambesicus.

The root extract and fractions of Croton zambesicus were screened for antimicrobial activity against some typed and pure cultures of bacterial and fungal species. These were carried out by the Plate-hole diffusion method on Mueller-Hinton agar (MHA) for bacteria and Sabouraud Dextrose Agar (SDA) for the fungi. The Minimum Inhibitory Concentrations (MICs) of test samples found to be active by the diffusion test were determined based on the macrodilution method. The crude extract as well as chloroform and n-hexane fractions had activity against B. subtilis only. While ethyl acetate fraction had a wide spectrum of activity against all the bacteria organisms tested with a promising minimum inhibitory concentrations. However, the crude extract and the fractions were inactive against all the fungal species tested. This result confirms its ethnomedicinal use in the treatment of microbial infections.

Antiinflammatory, analgesic and antipyretic activities of ethanolic root extract of Croton zambesicus.

The ethanolic root extract of C. zambesicus (27-81mg/kg) was evaluated for antiiflammatory, analgesic and antipyretic properties in mice. The extract (27-81mg/kg) demonstrated a weak antiinflammatory activity. However, a significant (P<0.01-0.001) analgesic and antipyretic activities were observed in all the experimental models tested. The extract may be exerting its effects through central mechanisms. These findings confirms its ethnomedical use in the treatment of malarial-associated symptoms.

Subchronic toxicity studies of the ethanolic root extract of Croton zambesicus.

Subchronic toxicity study of the crude root extract of Croton zambesicus (27-81 mg/kg), which is used traditionally as malarial remedy, was carried out in rodents to evaluate the safety profile. Effect of the extract on body weights, haematological indices as well as liver and kidney functions and histology of various organs were investigated. Subchronic treatment of rats for 21 days caused comparable increase in body weights of rats in extract treated and control groups. The extract caused a dose-dependent increases in RBC, PCV, Hb, WBC, bleeding time and clotting time. The increases were only significant (P<0.05) at the highest dose of the extract (81 mg/kg) for RBC and WBC when compared to control. There was no significant (P>0.05) differences in the means of other haematological parameters in the extract treated groups compared to control. The extract caused significant (P<0.05-0.01) increases in the level of serum total protein, ALT, ALP, total bilirubin and total cholesterol. The was no significant (P>0.05) changes in the levels of albumin and AST. The extract did not produce any significant (P>0.05) changes in the mean concentrations of urea, creatinine, Na+, K+, and Cl- ions of rats in the extract treated groups compared to that of control. Histopathologic analysis of the vital organs revealed no significant lesions in the brain, liver, kidney, heart, spleen, ovary, and testis. The results suggest the extract to be safe when taken orally though with an insignificant effect on the liver.

Antiplasmodial activity of root extract and fractions of Croton zambesicus.

AIM OF THE STUDY: Antiplasmodial activity of root extract and fractions of Croton zambesicus were evaluated to ascertain the folkloric claim of its antimalarial activity and elucidate its antiplasmodial mechanism of action. MATERIAL AND METHOD: The crude ethanolic root extract (27-81 mg/kg) and gradient fractions (n- hexane, chloroform, ethyl acetate and methanol; 54 mg/kg) of Croton zambesicus were investigated for antiplasmodial activity against chloroquine--sensitive Plasmodium berghei infections in mice. The antiplasmodial activity during early and established infections as well as the prophylactic activity were investigated. Chloroquine (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. Oxidant generation potentials of the crude extract and fractions was also evaluated to elucidate their mechanism of action. RESULTS: The crude root extract (27-81 mg/kg) demonstrated significant (P<0.01-0.001) schizonticidal activity during early and established infections and also had prophylactic activity. The activity was comparable to that of the standard drug used (chloroquine 5 mg/kg, pyrimethamine 1.2 mg/kg). Methanol, ethyl acetate and chloroform fractions had comparative in vivo antiplasmodial activity and oxidant generation potentials. CONCLUSION: The antiplasmodial activity of this root extract and fractions which is likely to be through peroxidation confirms the folkloric use of this plant.

Antiulcer and anticonvulsant activity of Croton zambesicus.

The ethanolic root extract of Croton zambesicus was investigated for its potential to protect gastric mucosa against ulcers induced by indomethacin, ethanol and reserpine. The anticonvulsant activity of the root extract against pentylene tetrazol (PTZ)- and picrotoxin-induced convulsion in mice was also studied. The extract (27-81 mg/kg) produced a significant (P<0.005-0.001) dose-dependent effects against the ulcerogenic effect of different agents used; indomethacin, ethanol and reserpine. The effect of the extract was lower than that of the standard drug, cimetidine (100 mg/kg) in the indomethacin and reserpine-induced ulcer models and higher than that of propranolol (40 mg/kg) in ethanol-induced ulcer model. The extract (27-81 mg/kg) could not protect mice from convulsion in both PTZ--and picrotoxin-induced convulsion. The root extract significantly (P<0.01-0.001) delayed the onset and latency of convulsion caused by PTZ and picrotoxin. The root extract possesses antiulcer and anticonvulsant properties.

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.

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.

Antidiabetic activities of ethanolic extract and fraction of Anthocleista djalonensis.

OBJECTIVE: To evaluate the antidiabetic activities of ethanolic root extract/fraction of Anthocleista djalonensis (A. djalonensis) in alloxan-induced diabetic rats. METHODS: A. djalonensis root extract/fractions (37-111 mg/kg) were administered to alloxan-induced diabetic rats for 14 days and blood glucose levels (BGLs) of the diabetic rats were monitored at intervals of hours and days throughout the duration of the treatment. RESULTS: Treatment of alloxan-induced diabetic rats with the extract/fractions caused a significant (P<0.001) reduction in fasting BGLs of the diabetic rats both in acute study and prolonged treatment (2 weeks). The activities of the extract and fractions were more than that of the reference drug, glibenclamide. CONCLUSIONS: These results suggest that the root extract/fractions of A. djalonensis possess antidiabetic effect on alloxan-induced diabetic rats and this justifies its use in ethnomedicine and can be exploited in the management of diabetes.

Antidiabetic and hypolipidemic activities of ethanolic leaf extract and fractions of Melanthera scandens.

OBJECTIVE: To evaluate the antidiabetic and hypolipidemic activities of ethanolic leaf extract and fraction of Melanthera scandens (M. scandens) in alloxan-induced diabetic rats. METHODS: M. scandens leaf extract/fractions (37-111 mg/kg) were administered to alloxan-induced diabetic rats for 14 days and blood glucose levels (BGL) of the diabetic rats were monitored at intervals of 7 hours for acute study and 14 days for prolonged study. Lipid profiles of the treated diabetic rats were determined after the period of treatment. RESULTS: Treatment of alloxan-induced diabetic rats with the extract/fractions caused a significant (P<0.001) reduction in fasting bloodglucose levels (BGL) of the diabetic rats both in acute study and prolonged treatment (2 weeks). The activities of the extract and fractions were more than that of the reference drug, glibenclamide. The extract/fractions exerted a significant reduction in the levels of serum total cholesterol, triglycerides, LDL and VLDL of extract with increases in HDL levels of the diabetic rats. CONCLUSIONS: These results suggest that the leaf extract/fractions of M. scandens possesses antidiabetic effect on alloxan induced diabetic rats and this justifies its use in ethno medicine and can be exploited in the management of diabetes.

Antiplasmodial and antiulcer activities of Melanthera scadens.

OBJECTIVE: To evaluate the antimalarial and antiulcerogenic activities of leaf extract and fractions of Melanthera scandens (M. scandens). METHODS: The crude leaf extract (37-111 mg/kg) and fractions (chloroform, ethylacetate and methanol; 78 mg/kg) of M. scadens were investigated for antiplasmodial activity against chloroquine-sensitive Plasmodium berghei infections in mice and for antiulcer activity against experimentally-induced ulcers. The antimalarial activity during early and established infections as well as prophylactic was investigated. Artesunate (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. Antiulcer activity of the crude extract was also evaluated against indomethacin, ethanol and histamine induced ulcers. RESULTS: The extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine-sensitive Plasmodium berghei infection in prophylactic, suppressive and curative models in mice. These reductions were statistically significant (P<0.001). They also improved the mean survival time (MST) from 9.28 to 17.73 days as compared with the control (P<0.01-0.001). The activities of extract/fractions were incomparable to that of the standard drugs i.e. artesunate and pyrimethamine. On experimentally-induced ulcers, the extract inhibited indomethacin, ethanol and histamine induced ulcers. These inhibitions were statistically significant (P<0.001) and in a dose-dependent fashion. CONCLUSIONS: The antiplasmodial and antiulcerogenic effects of this plant may in part be mediated through the chemical constituents of the plant.