Antipyretic and antimalarial activities of crude leaf extract and fractions of Enicostema littorale

ObjectiveTo evaluate the antiplasmodial and antipyretic activities of whole plant extract and fractions of Enicostemma littorale (E. littorale) for ascertaining the folkloric claim of its antimalarial and antipyretic activities.MethodsThe crude extract (260 – 780 mg/kg) and fractions (chloroform and acqeous; 520 mg/kg) of E. littorale were investigated for antiplasmodial activity against chloroquine-sensitive Plasmodium berghei (P. berghei) infections in mice and for antipyretic activity against dinitrophenol, amphetamine and yeast-induced pyrexia. The antiplasmodial activity during early and established infections as well as prophylactic were investigated. Artesunate (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Antipyretic activity of the crude extract was also evaluated against dinitrophenol, amphetamine and yeast-induced pyrexia.ResultsThe extract and fractions dose-dependently reduced parasitaemia induced by chloroquine-sensitive P. 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 from 11 to 27 days relative to control (P<0.01 – 0.001). The activities of extract/fractions were comparable to that of the standard drugs used (artesunate and pyrimethamine). On pyrexia induced by dinitrophenol, amphetamine and yeast, the extract caused inhibitions which were statistically significant (P<0.05 – 0.001) and in a dose-dependent fashion.ConclusionsThese plant extracts possess considerable antiplasmodial and antipyretic activities, which justify its use in ethnomedicine.     

Isolation,fractionation and evaluation of the antiplasmodial properties of Phyllanthus niruri resident in its chloroform fraction

ObjectiveTo investigate the antiplasmodial activity of Phyllanthus niruri (P. niruri) methanol extract (ME) and its fractions in mice.MethodsP. niruri methanol extract and its chloroform, ethanol and aqueous portions were tested against chloroquine-sensitive Plasmodium berghei berghei in early, established and repository models of infection using Knight and Peter's 4-day suppressive model, Ryley and Peters curative model and Peters prophylactic model respectively.ResultsChemosuppression of parasitaemia (37.65%–50.53 %) was elicited by 100–400 mg/kg (b.w.) of ME. At doses of 100 mg/kg b.w., the chloroform fraction (F1) significantly (P<0.01) suppressed parasitaemia by 85.29%, while ethanol and aqueous fractions (F2 and F3, respectively) elicited 67.06% and 51.18% chemosuppression. The most active fraction, F1 was selected for further antiplasmodial screening. In established infection, ME reduced parasitaemia (15.81%–62.96%) while F1 significantly (P<0.01) reduced parasitaemia (44.36%–90.48%), with effects comparable to that of chloroquine (96.48%). The prophylactic antiplasmodial activity of ME (92.50% suppression) was also significant (P<0.01) and was more effective than pyrimethamine (85.00%). Additionally, cell membrane integrity of non-parasitized erythrocytes incubated with 125–500 mg/mL F1 was maintained.ConclusionsThese findings indicate the antiplasmodial efficacy of P. niruri methanol extract, and the localization of this effect in its chloroform fraction.     

Antiplasmodial and antipyretic studies on root extracts of Anthocleista djalonensis against Plasmodium berghei

ObjectiveTo evaluate the antimalarial activities of ethanolic root extract/fractions of Anthocleista djalonensis (A. djalonensis) in Plasmodium berghei (P. berghei) infected mice.MethodsA. djalonensis root extract (175–1 000 mg/kg) and fractions (chloroform, ethyl acetate and methanol; 250 and 500 mg/kg) were investigated for antiplasmodial activity against chloroquine-sensitive Plasmodium berghei infections in mice and for antipyretic activity against dinitrophenol, amphetamine and yeast-induced pyrexia. The antiplasmodial activity during early and established infections as well as prophylactic were investigated. Artesunate (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Antipyretic activity of the crude extract was also evaluated against dinitrophenol, amphetamine and yeast-induced pyrexia.ResultsThe 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 from 13 to 28 days relative to control (P<0.001). The activities of extract/fractions were comparable to that of the standard drugs used (chloroquine and pyrimethamine). On pyrexia induced by dinitrophenol, amphetamine and yeast, the extract inhibited significantly (P<0.05 – 0.001) and in a dose-dependent fashion temperature rise caused by these pyrogens.ConclusionsA. djalonensis root extract has antiplasmodial and antipyretic activities which may in part be mediated through the chemical constituents of the plant.     

Antimalarial potency of the leaf extract of Aspilia africana (Pers.) C.D. Adams

ObjectiveTo investigate the antimalarial activity of ethanol extract of Aspilia africana (A. africana) leaf.MethodsThe ethanol extract of A. africana leaf (100–400 mg/kg) was screened for blood schizonticidal effect against chloroquine-sensitive Plasmodium berghei (P. berghei) in mice both in early and established models of antimalarial studies.ResultsThe leaf extract exhibited significant (P<0.05) antiplasmodial activity in 4-day early infection and in established infection tests with a considerable mean survival time comparable to that of standard drug, chloroquine (10 mg/kg).ConclusionsThe findings show that ethanol extract of A. africana leaf possesses potent antiplasmodial activity which justify the use in ethnomedicine and can be developed in malaria therapy.     

Antimalarial and analgesic activities of ethanolic leaf extract of Panicum maximum

ObjectiveTo evaluate antiplasmodial and analgesic activities of ethanolic leaf extract/fractions of Panicum maximum.MethodsThe crude leaf extract (47–190 mg/kg) and fractions (chloroform, ethyl acqeous and methanol; 96 mg/kg) of Panicum maximum were investigated for antiplasmodial activity against chloroquine sensitive Plasmodium berghei infections in mice and for analgesic activity against chemical and heat-induced pains. The antiplasmodial activity during early and established infections as well as prophylactic were investigated. Artesunate at 5 mg/kg and pyrimethamine at 1.2 mg/kg were used as positive controls. Analgesic activity of the crude extract/fractions was also evaluated against acetic acid, formalin and heat-induced pains.ResultsThe 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 from 13 to 28 days compared with control (P<0.001). The activities of extract/fractions were incomparable to that of the standard drugs (Artesunate and pyrimethamine). On chemically and thermally-induced pains, the extract inhibited acetic acid and formalin-induced inflammation as well as hot plate-induced pain in mice. These inhibitions were statistically significant (P<0.001) and in a dose-dependent fashion.ConclusionsPanicum maximum leaf extract has antiplasmodial and analgesic activities which may in part be mediated through the chemical constituents of the plant.     

In vivo antiplasmodial activities of ethanolic extract and fractions of Eleucine indica

ObjectiveTo evaluate the in vivo antiplasmodial activities of the extract and fractions (n-hexane, chloroform, ethylacetate, butanol, aqueous) of the whole plant in Plasmodium berghei berghei infected mice.MethodsOral administrations of the extract (200, 400, and 600 mg/kg) of Eleucine indica and fractions (400 mg/kg) were screened in the 4-day, repository and curative tests. Chloroquine (5 mg/kg), pyrimethamine (1.2 mg/kg) and artesunate (5 mg/kg) were used as controls.ResultsThe extract showed significant (P< 0.05–0.001) dose-dependent, antiplasmodial activity in the 4-day, repository and curative tests and increased the survival times of the infected mice. All the fractions exhibited significant antiplasmodial activity with the highest being ethylacetate fraction.ConclusionsEleucine indica extract and fractions possess antimalarial activity which confirms the ethnobotanical use of this plant as a malarial remedy and opens a new highway to further investigate its potentials in the on-going fight against malaria.     

Antiplasmodial and analgesic activities of Clausena anisata

ObjectiveAntiplasmodial and analgesic activities of the leaf extract and fractions of Clausena anisata (C. anisata) were evaluated for antimalarial and analgesic activities.MethodsThe crude leaf extract (39–117 mg/kg) and fractions (chloroform and acqeous; 78 mg/kg) of C. anisata were investigated for antiplasmodial activity against chloroquine-sensitive Plasmodium berghei (P. berghei) infections in mice using suppressive, prophylactic and curative models and analgesic activity against acetic acid, formalin and heat-induced pains. 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.ResultsThe extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine-sensitive P. berghei 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 17 to 21 days relative to control (P<0.01 ? 0.001). On chemically and thermally-induced pains, the extract inhibited acetic acid and formalin-induced inflammation as well as hot plate-induced pain in mice. These inhibitions were statistically significant (P<0.001) and in a dose-dependent fashion.ConclusionsThe antiplasmodial and analgesic effects of this plant may in part be mediated through its chemical constituents and it can be concluded that the C. anisata possess significant antimalarial and analgesic properties.     

In vitro and in vivo antiplasmodial activity and cytotoxicity of extracts of Phyllanthus niruri L. herbs traditionally used to treat malaria in Indonesia

In endemic areas where malaria is prevalent, medicinal plants are often used to treat malaria. This study was conducted to evaluate the in vitro and in vivo antiplasmodial activity and cytotoxicity of extracts of meniran (Phyllanthus niruri L.) herb traditionally used to treat malaria in Indonesia. Three extracts viz aqueous, methanolic and chloroformic extracts were obtained by maceration of the herbs. A radioactive method was used to evaluate the in vitro antiplasmodial activity of the extracts on chloroquine-resistant (FCR-3) and chloroquine-sensitive (D-10) strains of Plasmodium falciparum. In vitro antiplasmodial activity was expressed by the concentration inhibiting 50% of parasite growth (IC50). Cytotoxicity was estimated on Hela cells and the Cytotoxicity Index (CI = IC50 on HeLa cells/IC50 on FCR-3 strain) was calculated to evaluate the safety of tested extracts. A standard 4-day test on P berghei infected mice was used to evaluate the in vivo antiplasmodial activity of the extracts showing strong in vitro antiplasmodial activity, for both the methanolic and aqueous extracts. The in vivo antiplasmodial activity was expressed by the dose inhibiting 50% of parasite growth (ED50). The IC50 values obtained for these extracts against P. falciparum ranged from 2.3 to 202.4 microg/ml. The methanolic extract was the most active in vitro extract with an IC50 that ranged from 2.3 to 3.9 microg/ml and a CI that ranged from 41.3 to 57.5. This was also the most in vivo active extract with an ED50 of 9.1 mg/kg/d. Further study will be conducted to isolate and purify active compounds presented in the methanolic extract.     

Antimalarial potency of the methanol leaf extract of Maerua crassifolia Forssk (Capparaceae)

ObjectiveTo investigate the in vivo antiplasmodial effect of methanol leaf extract of Maerua crassifolia in mice infected with chloroquine sensitive Plasmodium berghei berghei.MethodsThe extract was evaluated for activity against early infection, curative effect against established infection at dose levels of 100, 200 and 400 mg/kg p.o. Chloroquine at 10 mg/kg was used as standard drug.ResultsA dose dependent chemo-suppression of the parasites was obtained at different dose levels of the extract tested with a considerable mean survival time.ConclusionsThe results support continued investigation of components of traditional medicines as potential new antimalarial agents.     

Larvicidal and repellent activity of medicinal plant extracts from Eastern Ghats of South India against malaria and filariasis vectors

ObjectiveTo evaluate the larvicidal and repellent activities of ethyl acetate and methanol extracts of Acacia concinna (A. concinna), Cassia siamea (C. siamea), Coriandrum sativum (C. sativum),Cuminum cyminum (C. cyminum), Lantana camara (L. camara), Nelumbo nucifera (N. nucifera) Phyllanthus amarus (P. amarus), Piper nigrum (P. nigrum) and Trachyspermum ammi (T. ammi) against Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus).MethodsThe larvicidal activity of medicinal plant extracts were tested against early fourth-instar larvae of malaria and filariasis vectors. The mortality was observed 24 h and 48 h after treatment, data were subjected to probit analysis to determine the lethal concentrations (LC₅₀ and LC₉₀) to kill 50 and 90 per cent of the treated larvae of the tested species. The repellent efficacy was determined against two mosquito species at five concentrations (31.25, 62.50, 125.00, 250.00, and 500.00 ppm) under the laboratory conditions.ResultsAll plant extracts showed moderate effects after 24 h and 48 h of exposure; however, the highest activity was observed after 24 h in the leaf methanol extract of N. nucifera, seed ethyl acetate and methanol extract of P. nigrum against the larvae of An. stephensi (LC₅₀ = 34.76, 24.54 and 30.20 ppm) and against Cx. quinquefasciatus (LC₅₀ = 37.49, 43.94 and 57.39 ppm), respectively. The toxic effect of leaf methanol extract of C. siamea, seed methanol extract of C. cyminum, leaf ethyl acetate extract of N. nucifera, leaf ethyl acetate and methanol extract of P. amarus and seed methanol extract of T. ammi were showed 100% mortality against An. stephensi and Cx. quinquefasciatus after 48 h exposer. The maximum repellent activity was observed at 500 ppm in methanol extracts of N. nucifera, ethyl acetate and methanol extract of P. nigrum and methanol extract of T. ammi and the mean complete protection time ranged from 30 to 150 min with the different extracts tested.ConclusionsThese results suggest that the leaf and seed extracts of C. siamea, N. nucifera, P. amarus, P. nigrum and T. ammi have the potential to be used as an ideal ecofriendly approach for the control of the An. stephensi and Cx. quinquefasciatus.     

Pharmacognostic study and anti – inflammatory activity of Phyllanthus reticulatus Poir. fruit

ObjectiveTo study pharmacognostic evaluation and anti – inflammatory activity of Phyllanthus reticulatus Poir. (P. reticulatus) fruit.MethodsThe fruit sample was studied by macroscopical, microscopical and other WHO recommended methods for standardisation. The hydroalcoholic extract of ripe fruit was also screened for anti-inflammatory activity by carrageenan induced left hind paw oedema in rat at doses of 200 mg/kg and 400 mg/kg, orally.ResultsTransverse section of fruit and powder study showed the presence of epicarp, mesocarp, endocarp, fibres and sclereids. Hydroalcoholic extract of fruit showed significant (P < 0.01) reduction of paw volume when compared with diclofenac sodium. The extract showed anti – inflammatory activity at 200 mg/kg and 400 mg/kg and was comparable with diclofenac sodium.ConclusionsPharmacognostic profile of Phyllanthus reticulatus provides the simplest and quickest means to establish the identity and purity and thereby assure the quality of sample. The hydroalcoholic extract shows significant anti – inflammatory activity at both doses when compared with standard drug diclofenac sodium (100 mg/kg).     

Antimicrobial, antiplasmodial, haemolytic and antioxidant activities of crude extracts from three selected Togolese medicinal plants

ObjectiveTo investigate the antioxidant, antimicrobial, antiplasmodial, acute toxicity and haemolytic activities of methanolic extracts of three plants. Phytochemical analysis to determine the phenolic contents was also carried out.MethodsThe 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging, NCCLS broth microdilution and Plasmodium Lactate Dehydrogenase (pLDH) assays were used to determine antioxidant, antimicrobial and antiplasmodial activities, respectively. Haemolysis assay was conducted on A⁺ human red blood cells and acute toxicity on male Swiss albino mice. Phenolics were quantitatively determined using spectrophotometric methods.ResultsThe DPPH assay yielded interesting antioxidant activities of methanolic extract of Parinari curatellifolia (P. curatellifolia) and Entada africana (E. africana) (IC₅₀ were 0.20±0.01 μg/mL and 0.47±0.01 μg/mL, respectively). This activity was highly correlated with phenolic contents of extracts. The antimicrobial tests displayed minimal inhibitory concentrations (MICs) values ranging from 0.90 to 1.80 mg/mL for Serratia marcescens (S. marcescens) the most susceptible bacterial strain. MIC value was 1.20 mg/mL for susceptible fungal strains including Mucor rouxi (M. rouxi), Fusarium oxyporum (F. oxyporum) and Rhizopus nigricans (R. nigricans). pLDH assay showed moderate antiplasmodial activity of Balanites aegyptiaca (B. aegyptiaca) (IC₅₀ = 24.56±3.45 μg/mL), however this extract was highly haemolytic and toxic in mice (LD₅₀ = 625±128 mg/kg).ConclusionsOur results support in part the use of the selected plants in the treatment of microbial infections. In addition the plant showed interesting antioxidant activity that could be useful in the management of oxidative stress.     

Protective effects of Phyllanthus acidus (L.) Skeels leaf extracts on acetaminophen and thioacetamide induced hepatic injuries in Wistar rats

ObjectiveTo investigate and compare the hepatoprotective effects of crude ethanolic and aqueous extracts of Phyllanthus acidus (L.) Skeels (P. acidus) leaves on acetaminophen (APAP) and thioacetamide (TAA) induced liver toxicity in wistar rats. Silymarin was the reference hepatoprotective agent.MethodsIn two different sets of experiments, the P. acidus extracts (200 and 400 mg/kg, body weight) and silymarin (100 mg/kg, body weight) were given orally for 7 days and a single dose of APAP (2 g/kg, per oral) or TAA (100 mg/kg, subcutaneous) were given to rats. The level of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin and total protein were monitored to assess hepatotoxicity and hepatoprotection.ResultsAPAP or TAA administration caused severe hepatic damage in rats as evident from significant rise in serum AST, ALT, ALP, total bilirubin and concurrent depletion in total serum protein. The P. acidus extracts and silymarin prevented the toxic effects of APAP or TAA on the above serum parameters indicating the hepatoprotective action. The aqueous extract was found to be more potent than the corresponding ethanolic extract against both toxicants. The phenolic and flavonoid content (175.02±4.35 and 74.68±1.28, respectively) and 2,2-diphenyl-1-picrylhydrazil (DPPH) [IC₅₀ = (33.2±0.31)μg/mL] scavenging potential was found maximum with aqueous extract as compared to ethanolic extract.ConclusionsThe results of present study suggests that the aqueous extract of P. acidus leaves has significant hepatoprotective activity on APAP and TAA induced hepatotoxicity, which might be associate with its high phenolic and flavonoid content and antioxidant properties.     

Immunostimulant activity of Phyllanthus reticulatus Poir: a useful plant for infectious tropical diseases

ObjectiveTo confirm the ethnomedicinal claim of Phyllanthus reticulatus Poir as immune enhancer.MethodsThe hydroalcoholic extract of fruits and leaves of the plant were evaluated for immunostimulant activity on albino mice at the dose levels of 100 and 200 mg/kg orally. The assessment of immunostimulant activity on specific and non-specific immunity was studied by neutrophil adhesion test, carbon clearance test and cyclophosphamide induced myelosuppression. Cyclophosphamide (30 mg/kg) was used to induce immunosuppresion in mice and levamisole (50 mg/kg) was used as immunostimulating agent.ResultsOral administration of both the doses of fruit and leaf extracts showed significant increase in phagocytic activity (^***P<0.001) and the percentage of neutrophil adhesion (^**P<0.01). Significant increase in white blood cell (^*P<0.05, ^**P<0.01) count was seen on administration of both the doses of fruits and leaves extracts.ConclusionsThe study demonstrates that both the plant parts triggers specific and non-specific responses and thus reveals a promise to hold immunostimulant activity.     

In vitro antiplasmodial activity of marine sponge Stylissa carteri associated bacteria against Plasmodium falciparum

ObjectiveTo identify the possible antiplasmodial drugs from bacteria associated with marine sponge Stylissa carteri (S. carteri).MethodsThe S. carteri samples were collected from Thondi coast and subjected for enumeration and isolation of associated bacteria. Filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μ g/mL) from isolated bacterial strains were screened for antiplasmodial activity against Plasmodium falciparum (P. falciparum) and potential extracts were also screened for biochemical constituents.ResultsTwelve samples of S. carteri were collected and subjected for enumeration and isolation of associated bacteria. The count of bacterial strains were maximum in November 2007 (34 × 10⁴ CFU/g) and the average count was maximum during the monsoon season (203 × 10³ CFU/g). Thirty two morphologically different bacterial strains were isolated from S. carteri and the ethyl acetate bacterial extracts were screened for antiplasmodial activity against P. falciparum. The antiplasmodial activity of a strain THB17 (IC₅₀ 20.56 μ g/mL) extract is highly comparable with the positive control chloroquine (IC₅₀ 19.59 μ g/mL) and 13 bacterial extracts which showed IC₅₀ value of more than 100 μ g/mL. Statistical analysis reveals that, significant in vitro antiplasmodial activity (P<0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes showed no morphological changes in erythrocytes by the ethyl acetate extract of bacterial strains after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of reducing sugars and alkaloids in the ethyl acetate extracts of bacterial strains.ConclusionsThe ethyl acetate extract of THB17 possesses lead compounds for the development of antiplasmodial drugs.     

In vitro antiplasmodial activity of marine sponge Clathria vulpina extract against chloroquine sensitive Plasmodium falciparum

ObjectiveTo explore the antiplasmodial potential of marine sponge Clathria vulpina (C. vulpina) against chloroquine sensitive Plasmodium falciparum (P. falciparum).MethodsThe marine sponge C. vulpina was collected from Thondi coast, authenticated and subjected for extraction by soaking in ethanol:water mixture (3:1 ratio). The percentage of extract was calculated. Filter sterilized extracts (100, 50, 25, 12.5, 6.25, 3.125 μg/mL) were screened for antiplasmodial activity against chloroquine sensitive P. falciparum. The extract was also tested for its hemolytic activity.ResultsThe percentage yield of extract of C. vulpina was found to be 4.8%. The crude extract of C. vulpina showed excellent antiplasmodial activity (IC₅₀=14.75 μg/mL) which was highly comparable to the positive control chloroquine (IC₅₀=7 μg/mL). Statistical analysis reveals that the significant antiplasmodial activity (P<0.05) was observed between the concentrations and the time of exposure. The chemical injury to erythrocytes was also carried out, which showed that there were no morphological changes in erythrocytes by the ethanolic extracts of sponges after 48 h of incubation. The extract showed slight hemolytic activity which almost equal to chloroquine at 100 μg/mL concentration (1.023%).ConclusionsThe marine sponge C. vulpina can be used as a putative antiplasmodial drug after completing successful clinical trials.     

In vitro antiplasmodial activity of ethanolic extracts of South Indian medicinal plants against Plasmodium falciparum

ObjectiveTo explore the antiplasmodial potential ofCatharanthus roseus L (C. roseus), Coccinea grandis (C. grandis), Thevetia peruviana (T. peruviana), Prosopis juliflora (P. juliflora), Acacia nilotica (A. nilotica), Azadirachta indica (A. indica) (Abr. Juss) and Morinda pubescens (M. pubescens).MethodsThe C. roseus L, C. grandis, T. peruviana, P. juliflora, A. nilotica, A. indica (Abr. Juss) and M. pubescens were collected from Ramanathapuram District, Tamil Nadu, India and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg/mL) were tested for antiplasmodial activity against Plasmodium falciparum. The phytochemical constituents in the potential extracts were also detected.ResultsOf the selected plants species, the bark extract of A. indica (Abr. Juss) showed excellent antiplasmodial activity (IC₅₀ 29.77 μg/mL) followed by leaf extract of A. indica (Abr. Juss) (IC₅₀47.20 μg/mL) and leaf extract of C. roseus L (IC₅₀49.63 μg/mL). The leaf, bark and flower extracts of P. juliflora showed IC₅₀values of more than 100 μg/mL. Statistical analysis reveals significant antiplasmodial activity (P<0.01) between the concentrations and time of exposure. Additionally, no chemical injury was found in the erythrocytes incubated with the ethanolic extract of all the tested plants. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, carbohydrates, flavonoids, phenols, saponins, triterpenoids, proteins and tannins in the ethanolic extracts of the tested plants.ConclusionsThe ethanolic bark extracts of A. indica (Abr. Juss) possess lead compounds for the development of antiplasmodial drugs.     

瑞香素抗红外期疟原虫作用的研究

目的　研究瑞香素 (DPNT)抗红外期疟原虫的作用。方法　于ICR小鼠腹腔注射约氏疟原虫子孢子后 0 5h灌胃给药 ,连续 4d。不同剂量的DPNT及DPNT伍用伯氨喹 (PQ)的抗疟作用 ,分别以d7ICR小鼠阴性率及d1 1 或d1 2 ICR小鼠每千个红细胞被原虫感染数作评价 ,并观察DPNT对ICR小鼠血红蛋白浓度的影响。结果　DPNT的剂量范围为每天 10～ 10 0mg/kg ,连服 4d ,d7原虫阴性小鼠数及d1 1 红细胞被感染程度与对照组相比其差异均无显著性 ;DPNT每天 5 0mg/kg和每天PQ5mg/kg配伍组的d7小鼠阴性率与PQ每天 10mg/kg组相当。ICR小鼠DPNT每天 5 0mg/kg组与对照组血红蛋白浓度在d8天有差异。结论　DPNT单独用药 ,无明显抗红外期疟原虫作用 ,但DPNT每天 5 0mg/kg与PQ每天 5mg/kg伍用的抗疟效果与PQ每天 10mg/kg相当。DPNT在短期内可致小鼠贫血。     

In vitro antiplasmodial effect of ethanolic extracts of traditional medicinal plant Ocimum species against Plasmodium falciparum

ObjectiveTo identify the possible antiplasmodial compounds from leaf, stem, root and flower extracts of Ocimum canum (O. canum), Ocimum sanctum (O. sanctum) and Ocimum basilicum (O. basilicum).MethodsThe O. canum, O. sanctum and O. basilicum were collected from Ramanathapuram District, Tamil Nadu and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg/mL) of leaf, stem, root and flower extracts of O. canum, O. sanctum and O. basilicum were tested for antiplasmodial activity against Plasmodium falciparum (P. falciparum). The potential extracts were also tested for their phytochemical constituents.ResultsThe leaf extract of O. sanctum showed excellent antiplasmodial activity (IC₅₀ 35.58 μg/mL) followed by leaf extract of O. basilicum (IC₅₀ 43.81 μg/mL). The leaf extract of O. canum, root extracts of O. sanctum and O. basilicum, the stem and flower extracts of all the three tested Ocimum species showed IC₅₀ values between 50 and 100 μg/mL. Statistical analysis reveals that, significant antiplasmodial activity (P <0.01) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out and it shows that, there were no morphological changes in erythrocytes by the ethanolic extract of O. canum, O. sanctum and O. basilicum. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, flavonoids, phenols, saponins, triterpenoids, proteins, resins, steroids and tannins in the ethanolic extracts of tested plants.ConclusionsThe ethanolic leaf extracts of O. sanctum possess lead compounds for the development of antiplasmodial drugs.     

Immunomodulatory activity of an aqueous extract of Polygonum minus Huds on Swiss albino mice using carbon clearance assay

ObjectiveTo explore the immunomodulatory properties of aqueous extract of Polygonum minus Huds (P. minus), on swiss albino mice using carbon clearance assay.MethodsThe study was performed using in-vivo carbon clearance assay or phagocytosis. Aqueous extract of P. minus was administered by oral route to Swiss albino mice for seven days. Levamisole, 2.5 mg/kg was used as standard drug.ResutlsThe phagocytic function of reticuloendothelial system was significantly (P<0.05) enhanced by levamisole and P. minus aqueous extract groups compared to the control. Treatment with aqueous extract of P. minus at 200 and 400 mg/kg body weight resulted in dose dependent increase in phagocytic index (K) where phagocytic index of aqueous extract of P. minus at 400 mg/kg body weight is comparable to the standard drug Levamisole at 2.5 mg/kg body weight.ConclusionsAqueous extract of P. minus has exhibited significant increase in phagocytosis at doses of 200 mg/kg body weight and 400 mg/kg body weight.