In silico approach of naringin as potent phosphatase and tensin homolog (PTEN) protein agonist against prostate cancer.

Prostate cancer (PC) is one of the major impediments affecting men, which leads approximately 31,620 deaths in both developing and developed countries. Although some chemotherapy drugs have been reported for prostate cancer, they are not effective due to the lack of safety, efficacy and low selectivity. Hence, the novel alternative anticancer agents with remarkable effect are highly appreciable. Natural plants contain several bio-active compounds which have been traditionally used for the various medical treatments. Particularly, naringin is a natural bio-active compound commonly found in the citrus fruits, which have shown numerous biological activities. Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene, which activates both lipid phosphates and protein phosphates. The PTEN gene is negative regulator of PI3K/AKT/mTOR pathways, since, this signaling pathway play an essential role in the cell survival, proliferation and migration. In the present in silico investigation, structure based virtual screening, molecular docking, molecular dynamics simulation and Adsorption, Distribution, Metabolism, Excretion (ADME) prediction were employed to determine the binding affinity, stability and drug likeness properties of top ranked screened compounds and naringin, respectively. The results revealed that the complex has good molecular interactions, binding stability (peak between 0.3 and 0.4 nm) and no violations in the Lipinski Rule of 5 in naringin, but the screened compounds violated the drug likeness properties. From the in silico analyses, it is identified that naringin compound might assist in the development of novel therapeutic candidate against prostate cancer. Communicated by Ramaswamy H. Sarma.

Fucoidan serves a neuroprotective effect in an Alzheimer's disease model.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that causes memory and cognitive deficits. The present study was carried out to evaluate the protective effects of fucoidan in monocrotophos induced AD in Drosophila melanogaster. In silico studies showed that fucoidan exhibited binding energy of -9.3 kcal with proteins. Consistent with this, fucoidan, in a dose and time-dependent fashion, had inhibitory activity against cholinergic and monoamine-metabolized enzymes in vitro. Fucoidan inhibited the increase in total mRNA and protein in monocrotophos fed flies and prevented changes in biochemicals, neurochemicals and latency time of locomotor, learning and memory induced by monocrotophos. Together, the findings show that fucoidan serves a neuroprotective effect in Alzheimer's disease model in D. melanogaster.

Isolation, structural elucidation and antiplasmodial activity of fucosterol compound from brown seaweed, Sargassum linearifolium against malarial parasite Plasmodium falciparum.

The brown seaweed, Sargassum linearifolium (Turner) C. Agardh, 1820 is commonly available along the south-east coast of India. Its compound fucosterol was isolated and confirmed through spectral characterisation and chemical transformation methods. The antiplasmodial effect of the isolated fucosterol was investigated against the 3D7 chloroquine sensitive Plasmodium falciparum strain, parasitaemia percentage was determined at 48 h and morphological change was studied through microscopic examination after Giemsa staining. A perceptible antiplasmodial effect was produced by fucosterol compound against the P. falciparum and positive control, chloroquine with the IC50 values (µg/mL) of 7.48 and 12.81, respectively. Fucosterol showed higher antiplasmodial activity as compared to chloroquine. It is inferred that both the fucosterol and chloroquine could have inhibited the schizont stage of the parasite during the intra-erythrocyte asexual development. The findings underline the usefulness of the seaweed-based fucosterol and further studies are warranted.

In vitro antiplasmodial activity of bacterium RJAUTHB 14 associated with marine sponge Haliclona Grant against Plasmodium falciparum.

Malaria is the most important parasitic disease, leading to annual death of about one million people, and the Plasmodium falciparum develops resistance to well-established antimalarial drugs. The newest antiplasmodial drug from a marine microorganism helps in addressing this problem. In the present study, Haliclona Grant were collected and subjected for enumeration and isolation of associated bacteria. The count of bacterial isolates was maximum in November 2007 (18 × 10(4) colony-forming units (CFU) g(-1), and the average count was maximum during the monsoon season (117 × 10(3) CFU g(-1)). Thirty-three morphologically different bacterial isolates were isolated from Haliclona Grant, and the extracellular ethyl acetate extracts were screened for antiplasmodial activity against P. falciparum. The antiplasmodial activity of bacterium RJAUTHB 14 (11.98 µg[Symbol: see text]ml(-1)) is highly comparable with the positive control chloroquine (IC(50) 19.59 µg[Symbol: see text]ml(-1)), but the other 21 bacterial extracts showed an IC(50) value of more than 100 µg[Symbol: see text]ml(-1). 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 isolates 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 bacterium RJAUTHB 14. The 16S rRNA gene partial sequence of bacterium RJAUTHB 14 is deposited in NCBI (GenBank accession no. GU269569). It is concluded from the present study that the ethyl acetate extracts of bacterium RJAUTHB 14 possess lead compounds for the development of antiplasmodial drugs.

In vitro antiplasmodial effect of ethanolic extracts of coastal medicinal plants along Palk Strait against Plasmodium falciparum.

OBJECTIVE: To identify the possible antiplasmodial compounds from Achyranthes aspera (A. aspera), Acalypha indica (A. indica), Jatropha glandulifera (J. glandulifera) and Phyllanthus amarus (P. amarus). METHODS: The A. aspera, A. indica, J. glandulifera and P. amarus were collected along Palk Strait 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 A. aspera, A. indica, J. glandulifera and P. amarus were tested for antiplasmodial activity against Plasmodium falciparum. The potential extracts were also tested for their phytochemical constituents. RESULTS: Of the selected plants species parts, the stem extract of A. indica showed excellent antiplasmodial activity (IC50= 43.81µg/mL) followed by stem extract of J. glandulifera (IC50= 49.14µg/mL). The stem extract of A. aspera, leaf and root extracts of A. indica, leaf, root and seed extracts of J. glandulifera and leaf and stem extracts of P. amarus showed IC50 values between 50 and 100 µg/mL. Statistical analysis revealed 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 showed that there were no morphological changes in erythrocytes by the ethanolic extract of all the tested plant extracts. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, flavonoids, phenols, saponins, triterpenoids, proteins, and tannins in the ethanolic extracts of tested plants. CONCLUSIONS: The ethanolic stem extracts of P. amarus and J. glandulifera possess lead compounds for the development of antiplasmodial drugs.

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

OBJECTIVE@#To 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).@*METHODS@#The 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.@*RESULTS@#The leaf extract of O. sanctum showed excellent antiplasmodial activity (IC(50) 35.58 μg/mL) followed by leaf extract of O. basilicum (IC(50) 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 IC(50) 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.@*CONCLUSIONS@#The ethanolic leaf extracts of O. sanctum possess lead compounds for the development of antiplasmodial drugs.

In vitro antiplasmodial activity of spiro benzofuran compound from mangrove plant of Southern India

OBJECTIVE@#To find out the in vitro antiplasmodial activities of mangrove leaf extracts.@*METHODS@#In vitro antiplasmodial assay was carried out with 13 different mangrove plants. Column chromatography was performed with the most potent Agecerious corniculatum (A. corniculatum) by using various solvent extractions. GC-MS was also preformed with the most potent ethanolic fraction of the A. corniculatum extract.@*RESULTS@#Of the 13 mangroves plants, A. corniculatum showed maximum percentage of parasitemia suppression (94.98 ± 1.16)%. Column chromatography was performed with A. corniculatum with different solvents and the methanolic extract showed maximum percentage (99.73±1.63)% of parasitemia inhibition at 150 μg/mL concentration with the IC(50) value of (29.28±3.23) μg/mL concentration. The results of the GC-MS analysis observed that, the most potent methanolic extract showed maximum retention time (30.687 RT) and the chemical class was identified as Spiro [benzofuran-2(3 H), 1'(3 cyclohexane)-2',3-dione, 7-chloro-4',6] which was responsible for the antiplasmodial activity.@*CONCLUSIONS@#It is concluded from the present study that, the chemical constituents of A. corniculatum collected from Pichavaram mangrove forest can be used as a putative antiplasmodial drugs in future.

Antiviral, antioxidant and toxicological evaluation of mangrove associate from South East coast of India

Objective: To identify the antiviral antioxidant and toxicological evaluation of marine halophyte.Methods:Mangrove associates such as Salicornia brachiata, Clerodendron inerme, Rhizophora lamarckii, Suaeda maritima were collected. In vitro antiviral studies such as HBsAg binding assay, DNA polymerase inhibition assay, RT inhibition assay were carried out. Moreover, antioxidant properties, ash content, elemental analysis, LD50 analysis were measured for theS. maritima leaf extract which was the most potent. Results: S. maritima leaf extract showed minimum concentration of IC50 value with HBsAg binding assay, DNA polymerase inhibition assay, RT inhibition assay as 325.98, 843.09 and 587.32 μg/ml concentrations respectively. Antioxidant properties of S. maritima leaf extract showed the minimum concentration (23.64±5.27μg/ml) of IC50 value with the nitric oxide scavenging assay, followed by DPPH assay (112.03±18.39μg/ml). The ash content of S. maritima leaf extract was varied between 8.05% to 87.30%concentrations. The elemental analysis of S. maritima showed the values within the limits of WHO guidelines. The lethal dose of S. maritima leaf extract was identified as 3000 mg/kg/body weight. The sub acute toxicity was not showed any significant differences with organ weights between control and extract treated animals. Biochemical parameters such as SGOT, SGPT, ALP, sugar and urea were not showed any significant variations between control and extract treated animals. But, the results of haematological parameters such as WBC (6600±234.90 cells/cumm), lymphocytes (69±14.09), polymorphs (38±9.38), eosinophils (02±0.00) were found significantly increased with extract treated animals. Phytochemical analysis of S. maritima leaf extract showed the presence of various phytochemical constituents such as reducing sugars, polyophenols, flavonoids and tannins with the leaf extract. Conclusions: The results of the present findings pave the way for the identification of novel molecules for the possible utilization of antiviral and antioxidant drugs from Suaeda maritima leaf.

In vitro antiplasmodial activity of marine sponge Clathria indica associated bacteria against Palsmodium falciparum

Objective: To identify the possible antiplasmodial drugs from bacteria associated with marine sponge Clathria indica. Methods: Clathria indica 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 μg.mL-1) from isolated bacterial isolates were screened for antiplasmodial activity against Palsmodium falciparum and potential extracts were also screened for biochemical constituents. Results: The count of bacterial strains were maximum in November 2007 (19×104 CFU.g-1) and the average count was maximum during the monsoon season (107×10 3 CFU.g-1). Thirty one morphologically different bacterial isolates were isolated from Clathria indica and the ethyl acetate bacterial extracts were screened for antiplasmodial activity against Palsmodiumfalciparum. The antiplasmodial activity of a isolate THB23 (IC 50 28.80 μg.mL-1) extract is highly comparable with the positive control chloroquine (IC50 19.59 μg.mL-1) and 17 bacterial extracts which showed IC50 value of more than 100 μg.mL-1. 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 carbohydrates and alkaloids in the ethyl acetate extracts of bacterial isolates. Conclusions: The ethyl acetate extracts of THB23 possesses novel compounds for the development of antiplasmodial drugs.

In vitro antiplasmodial effect of ethanolic extracts of coastal medicinal plants along Palk Strait against Plasmodium falciparum

Objective: To identify the possible antiplasmodial compounds from Achyranthes aspera (A. aspera), Acalypha indica (A. indica), Jatropha glandulifera (J. glandulifera) and Phyllanthusamarus (P. amarus). Methods: The A. aspera, A. indica, J. glandulifera and P. amarus were collected along Palk Strait 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 A. aspera, A. indica, J. glandulifera and P. amarus were tested for antiplasmodial activity against Plasmodiumfalciparum. The potential extracts were also tested for their phytochemical constituents. Results:Of the selected plants species parts, the stem extract of A. indica showed excellent antiplasmodial activity (IC50= 43.81μg/mL) followed by stem extract of J. glandulifera (IC50= 49.14μg/mL). The stem extract of A. aspera, leaf and root extracts of A. indica, leaf, root and seed extracts of J.glandulifera and leaf and stem extracts of P. amarus showed IC 50 values between 50 and 100 μg/mL. Statistical analysis revealed 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 showed that there were no morphological changes in erythrocytes by the ethanolic extract of all the tested plant extracts. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, flavonoids, phenols, saponins, triterpenoids, proteins, and tannins in the ethanolic extracts of tested plants. Conclusions: The ethanolic stem extracts of P. amarus and J. glandulifera possess lead compounds for the development of antiplasmodial drugs.

Hepatoprotective and antioxidant properties of marine halophyte Luminetzera racemosa bark extract in CCL(4) induced hepatotoxicity.

OBJECTIVE: To identify the hepatoprotective and antioxidant activity of Luminetzera racemosa (L. racemosa) bark extract. METHODS: Wistar albino rats were divided into 6 groups: Group 1 served as control; Group 2 served as hepatotoxin (CCL(4) treated) group; Group 3 served as positive control (Silymarin) treated groups; Group 4, 5 and 6 served as (100, 200 and 300 mg/kg bw p.o.) L. racemosa bark extract treated groups. Moreover, in vitro antioxidant indexes, including DPPH, hydroxyl radical scavenging activity (HRSA), NO, ferric reducing antioxidant power (FRAP), lipid hydroperoxide (LPO) and super oxide dismutase (SOD) were also analyzed in the bark extract. RESULTS: The results suggested that, the level of serum glutamate oxyloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatise (ALP), bilurubin, cholesterol, sugar and lactate dehydrogenase (LDH) were significantly (P<0.05) increased in hepatotoxin treated rats when compared with the control group. But, the maximum reduction of SGOT [(225.36±13.65) IU/L], SGPT [(96.85±17.36) IU/L], ALP [(315.37±17.16) IU/L], bilirubin [(2.97±0.46) mg/dL], cholesterol [(163.73±17.54) mg/dL], sugar [(127.35±27.35) mg/dL] and LDH [(1 784.00±268.36) IU/L] were observed with 300 mg/kg bw of bark extract treated rats. Histopathological scores showed that, no visible changes were observed with high dose (300 mg/kg bw) of bark extract treated rats except mild fatty changes. The in vitro antioxidant assays showed that, the IC(50) values were observed as (44.17±6.87) µg/mL, (42.45±2.81)µg/mL, (62.37±3.98)µg/mL, (54.24±3.09)µg/mL, (87.25±5.90) µg/mL and (71.54±5.42)µg/mL for DPPH, HRSA, NO, FRAP, LPO and SOD radical scavenging activities, respectively. CONCLUSIONS: The hepatoprotective and antioxidant activities of the bark extract might be to the presence of unique chemical classes such as flavonoids, alkaloids and polyphenols.

Antiplasmodial activity of two marine polyherbal preparations from Chaetomorpha antennina and Aegiceras corniculatum against Plasmodium falciparum.

The ocean covers more than 70% of earth surface and hosts most 300,000 described species of plants and animals to use, which have been virtually unexploited for the development of medicines. Marine plants are the good source of biologically active entities which exhibit therapeutic properties, when applied single or in combination of different plant extracts (polyherbal). Polyherbal preparations are always a complex mixture of different forms and thus different compounds, which might act as agonistic, synergistic, complementary, antagonistic or toxic way. The present study was initially carried out to test the antiplasmodial activity of 13 mangrove plants and eight seaweeds species distributed along the coast of south India. Of these, mangrove species Aegiceras corniculatum and the seaweed species Chaetomorpha antennina have shown maximum antiplasmodial activity. Hence, the present study was mooted out to increase the percentage of antiplasmodial activity when applied as polyherbal preparations. The effect of marine polyherbal preparations from the methanolic extracts of two marine plants A. corniculatum and C. antennina for their antiplasmodial activity was tested. It shows that the polyherbal extract showed 63.50 ± 0.408% suppression of parasitaemia against Plasmodium falciparum at 1.5 mg ml⁻¹ concentration. In vivo test was carried out with rat animal model to find out the effectiveness of the polyherbal extracts in the live system, which reveals that polyherbal extracts have exhibited remarkable antiplasmodial activity (50.57 ± 0.465%) against Plasmodium berghei at 120 mg kg⁻¹ bw. This study shows that combinations of mangrove plants and seaweeds extracts had a source of lead compounds for the development of new drugs for the treatment of malaria.

In vitro antiplasmodial activity of ethanolic extracts of mangrove plants from South East coast of India against chloroquine-sensitive Plasmodium falciparum.

Malaria is one of the most prevalent infectious diseases in the world. Treatment for malaria is commonly inadequate due to the lack of quality assured effective drugs. The effectiveness of these drugs is declining at an ever accelerating rate, with consequent increase in malaria related morbidity and mortality. The newest antiplasmodial drug from plants is needed to overcome this problem. Numerous mangroves and mangal associates are used as folklore medicine to treat various human diseases. The mangrove plant species are a good source of potential bioactive entities which exhibits many therapeutic properties. The present study was carried out to test the antiplasmodial activity of five mangrove plant species distributed along the South East coast of India. Bruguiera cylindrica, Ceriops decandra, Lumnitzera racemosa, Rhizophora apiculata, and Rhizophora mucronata mangrove plant extracts exhibited in vitro antiplasmodial activity against chloroquine-sensitive Plasmodium falciparum. Of which, the ethanolic bark extract of R. mucronata exhibited high antiplasmodial activity (IC(50)=62.18 µg.ml(-1)). Statistical analysis reveals that, significant antiplasmodial activity (P<0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out and it shows that no morphological differences in erythrocytes by the ethanolic extract of mangrove plants after 48 h of incubation. The screening for phytochemical constituents in the mangrove plants were carried out and it reveals that, the presence of alkaloids, triterpenes, flavonoids, tannins, catachin, anthroquinone, phenols, sugars, and proteins. This study shows that the mangrove plants had a source of lead compounds for the development of new drugs for the treatment of malaria.

Hepatoprotective and antioxidant activity of a mangrove plant Lumnitzera racemosa.

OBJECTIVE: To identify the hepatoprotective and in vitro antioxidant activity of Lumnitzera racemosa (L. racemosa) leaf extract. METHODS: Animals in Group 1 served as vehicle control, Group 2 served as hepatotoxin (CCL4 treated) group, Group 3 served as positive control (Silymarin) group, and Group 4, 5 and 6 served as (75, 150 and 300 mg/kg bw p.o.) L. racemosa leaf extract treated groups. Moreover, in vitro antioxidant DPPH, hydroxyl radical scavenging activity (HRSA), NO, ferric reducing antioxidant power (FRAP), lipid hydroperoxide (LPO) and super oxide dismutase (SOD) were also analyzed for the leaf extract. RESULTS: The levels of the serum parameters such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), bilirubin, cholesterol (CHL), sugar and lactate dehydrogenase (LDH) were significantly increased in CCL4 treated rats when compared with the control group (P<0.05). But the L. racemosa leaf extract treated rats showed maximum reduction of SGOT [(210.36±19.63) IU/L], SGPT [(82.37±13.87) IU/L], ALP [(197.63±23.43) IU/L], bilurubin [(2.15±0.84) mg/dL], cholesterol [(163.83±15.63) mg/dL], sugar [(93.00±7.65) mg/dL] and LDH [(1134.00±285.00) IU/L] were observed with the high dose (300 mg/kg bw) of leaf extract treated rats. Histopathological scores showed that, no visible changes were observed with high dose (300 mg/kg bw) of leaf extract treated rats except few mild necrosis. The IC50 values were observed as (56.37±4.87) µg/mL, (57.68±1.98) µg/mL, (64.15±2.90) µg/mL, (61.94±3.98) µg/mL, (94.53±1.68) µg/mL and (69.7±2.65) µg/mL for DPPH, HRSA, NO, FRAP, LPO and SOD radical scavenging activities, respectively. CONCLUSIONS: In conclusion, the hepatoprotective effect of the L. racemosa leaf extract might be due to the presence of phenolic groups, terpenoids and alkaloids and in vitro antioxidant properties.

Seaweeds as a source of lead compounds for the development of new antiplasmodial drugs from South East coast of India.

The problems of resistant lines of Plasmodium falciparum are escalating. Twelve seaweeds species belong to five different families (Sargassaceae, Gracilariaceae, Hypneaceae, Corallinaceae and Halimedaceae) were collected from Mandapam coastal area, and the seaweeds extracts were tested for in vitro antiplasmodial activity against P. falciparum. Among the tested seaweeds, Gracilaria verrucosa (IC(50) 5.55 µg.ml(-1)) and Hypnea espera (IC(50) 8.94 µg.ml(-1)) showed good antiplasmodial activity, and these results are comparable with positive controls such as artemether (IC(50) 4.09 µg.ml(-1)) and chloroquine (IC(50) 19.59 µg.ml(-1)), respectively. Turbinaria conoides, Sargassum myriocystem, Hypnea valentiae and Jania rubens extracts showed IC(50) values between 5 to 50 µg.ml(-1). Sargassum sp., Turbinaria decurrens and Halimeda gracilis extracts showed IC(50) values between 50 to 100 µg.ml(-1). Gracilaria corticata, Jania adherens and Halimeda opuntia extracts showed IC(50) value of more than 100 µg.ml(-1). 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 was also carried out, and it shows that no morphological changes in erythrocytes by the ethanolic extract of seaweeds extracts after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of sugars, proteins, phenols and carboxylic acid in the ethanolic extracts of seaweeds. It is concluded from the present study that the ethanolic extracts of seaweeds of G. verrucosa and Hypnea espera possess lead compounds for development of antiplasmodial drugs.

In vitro antiplasmodial activity of ethanolic extracts of seaweed macroalgae against Plasmodium falciparum.

Malaria is a major health problem in many developing countries. The drugs resistant Plasmodium falciparum causes the most virulent form of malaria in humans and it is described as a public health disaster causing increased morbidity and mortality. Thirteen seaweeds species which belong to four different families (Rhodomelaceae, Cladophoraceae, Ulvaceae, and Caulerpaceae) were collected from Mandapam coastal area and the seaweeds extracts were tested for in vitro antiplasmodial activity against P. falciparum. Among them, Caulerpa toxifolia (IC(50) 5.06 µg·ml(-1)) showed potential antiplasmodial activity than other seaweeds extracts and it can be comparable with the positive control artemether (IC(50) 4.09 µg·ml(-1)). Caulerpa peltata (IC(50) 16.69 µg·ml(-1)) also exhibited good antiplasmodial activity and the IC(50) value is lesser than the positive control chloroquine (IC(50) 19.59 µg·ml(-1)). 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 was also carried out and it shows that no morphological changes in erythrocytes by the ethanolic extract of seaweeds extracts after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of sugars, proteins, and phenols in the ethanolic extracts of seaweeds. It is concluded from the present study that, the ethanolic extracts of seaweeds of C. toxifolia and C. peltata possesses lead compounds for development of antiplasmodial drugs.

Mangrove plants as a source of lead compounds for the development of new antiplasmodial drugs from South East coast of India.

Malaria is the world's leading killer among the infectious diseases. The treatment of malaria is mystified by the challenges of widespread resistance of the malaria parasites to cheap and affordable antimalarial drugs. The present study was made in an attempt to identify the in vitro antiplasmodial activity against mangrove plant parts. (Avicennia marina, Acanthus ilicifolius, Bruguiera cylindrica, Excoecaria agallocha, Rhizophora apiculata, and Rhizophora mucronata mangrove plant extracts exhibited in vitro antiplasmodial activity against Plasmodium falciparum). Of the selected mangrove plant parts, the bark extract of A. marina exhibited minimum concentration of inhibitory activities IC(50) 49.63 µg.ml(-1). The leaf extract of A. marina, the hypocotyl extract of B. cylindrica, the leaf extract of E. agallocha, the flower extract of R. mucronata, and the hypocotyl extract of R. apiculata showed IC(50) values between 50 and 100 µg.ml(-1). Statistical analysis reveals that significant antiplasmodial activity (P<0.05) 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 mangrove plants after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of alkaloids, carboxylic acids, coumarins, saponins, flavonoids, xanthoproteins, tannins, phenols, sugars, resins, steroids, and proteins in the ethanolic extracts of mangrove plants. It is concluded from the present study that the ethanolic extracts of mangrove plant parts of A. marina possess lead compounds for the development of antiplasmodial drugs.

In vitro antiplasmodial activity of marine sponge Hyattella intestinalis associated bacteria against Plasmodium falciparum

Objective: To identify the antiplasmodial drugs from the marine sponge Hyattella intestinalis (H. intestinalis) associated bacteria. Methods: The H. intestinalis 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 3.125μg/mL) from bacterial isolates were screened for antiplasmodial activity against P. falciparum and potential extracts were also screened for biochemical constituents. Results: The count of THB isolates were maximum in November 2007 (20×10 4 CFU/g) and the average count was maximum during the monsoon season (77×103 CFU/g). A total of 29 bacteria were isolated based on the morphological characteristics and screened for antiplasmodial activity. The antiplasmodial activity of THB20 extract (IC50 41.88 μg/mL) showed at two fold concentration of IC50 value of the positive control chloroquine (IC50 19.59 μg/mL) and 14 bacterial isolates showed IC50 value of more than 100 μg/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 THB isolates after 48 h of incubation. The antiplasmodial activity of potential bacterial isolates might be due to the presence of sugars and alkaloids in the ethyl acetate extracts. Conclusions: It is concluded from the present study that, the ethyl acetate extracts of THB20 posses novel metabolites for the development of newer antiplasmodial drugs.