Antimicrobial constituents from three endophytic fungi

ObjectiveTo evaluate the antimicrobial potential of extracts of the endophytic fungi Plectophomella sp., Physalospora sp., and Crataegus monogyna (C. monogyna) and study the tentative identification of their active constituents.MethodsCrude extracts and isolated compounds were screened for antimicrobial activity using the agar well diffusion method. Four compounds were purified from three endophytic fungi using column chromatography and their structures have been assigned based on their ¹H and ¹³C nuclear magnetic resonance spectra.ResultsPlectophomella sp., Physalospora sp., and C. monogyna extracts showed promising antifungal, antibacterial and herbicidal properties. (-)-Mycorrhizin A was isolated from Plectophomella sp. while cytochalasins E and K were isolated from Physalospora sp. Similarly radicinin was purified from the endophytic fungus C. monogyna. The ethyl acetate extract of Plectophomella sp. showed significant antifungal activity towards Ustilago violacea (U. violacea) and Eurotium repens (E. repens) and significant antibacterial activity against Bacillus megaterium. Interestingly, the ethyl acetate extracts of Physalospora sp. and C. monogyna showed strong herbicidal and antifungal activities towards Chlorella fusca, U. violacea, E. repens, Mycotypha microspora (M. microspora), Fusarium oxysporum, Escherichia coli, and Bacillus megaterium. (-)-Mycorrhizin A showed significant antifungal activity towards U. violacea and E. repens. Cytochalasins E and K showed strong antifungal activity against E. repens and M. microspora especially towards fungal Mycotypha microspora. Similarly cytochalasins E and K showed good herbicidal activity towards Chlorella fusca. Radicinin showed strong antifungal activity against E. repens and M. microspora.ConclusionsAntimicrobial activities demonstrated by the extracts of the endophytic fungi Plectophomella sp., Physalospora sp., and C. monogyna and four isolated compounds clearly demonstrate that these fungi extracts and active compounds present a great potential use in the food, cosmetic and pharmaceutical industries.     

Evaluation of extracts and essential oil from Callistemon viminalis leaves: Antibacterial and antioxidant activities,total phenolic and flavonoid contents

ObjectiveTo investigate antioxidant and antibacterial activities of Callistemon viminalis (C. viminalis) leaves.MethodsThe essential oil of C. viminalis leaves obtained by hydro-distillation was analyzed by GC/MS. Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant (DPPH assay) and antibacterial (agar disc diffusion and 96-well micro-plates methods) actives.ResultsFourteen components were identified in the essential oil, representing 98.94% of the total oil. The major components were 1,8-cineole (64.53%) and α-pinene (9.69%). Leaf essential oil exhibited the highest antioxidant activity of (88.60±1.51)% comparable to gallic acid, a standard compound [(80.00±2.12)%]. Additionally, the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic (tetracycline). The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.ConclusionsIt can be suggested that C. viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis. The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C. viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.     

Antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis

ObjectiveTo explore antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis (A. officinalis).MethodsIn the present study the leaf extracts of A. officinalis were examined for its antibacterial potential using five different solvents against some reference strains of human pathogenic bacteria for the crude extract. Maximum activity was observed for ethyl acetate and hence different concentrations like 15 μL, 25 μL, and 50 μL of ethyl extracts was checked for its antibacterial activity. Partial purification of crude extract was carried by column chromatography and fractions were analyzed using gas chromatography-mass spectrometry (GC-MS) to identify compounds.ResultsThe crude ethyl acetate extracts of A. officinalis showed remarkable antibacterial activity with zones of inhibition of 13 mm against Eschericia coli (E. coli) and 11 mm against Staphylococcus aureus (S. aureus). Fraction 13 (ethyl acetate÷methanol= 8÷2) as the most potent one against with the minimal inhibitory concentration of 30 mm against E. coli and 25 mm against S. aureus. The GCMS resultsof active column fraction (F13) revealed that the active principals were a mixture of hydroxy-4 methoxybenzoic acid, diethyl phthalate, oleic acid.ConclusionsThe leaf extracts with proven antibacterial effects can clearly be directed towards cancer treatment as to inhibiting cancer cell growth. The limited number of test organisms owes to a constraint of resource. So, the effect of strong bursts of leaf extracts on human pathogenic bacteria should further be tested on a wide range of test organisms.     

Composition of the non-polar extracts and antimicrobial activity of Chorisia insignis HBK. leaves

ObjectiveTo investigate the chemical constituents of the petroleum ether extract and the ether fraction of the 70% ethanol extract of Chorisia insignis HBK. leaves, as well as screen its antimicrobial activity.MethodsDifferent chromatographic methods were applied to investigate the non-polar extracts and the diffusion assay method was applied to study the antimicrobial activity.ResultsA total of 50 compounds from the unsaponifiable matter and 20 fatty acid methyl esters were identified from the petroleum ether extract by GC/MS analysis. n-Hentriacontane, n-tritriacontane, stigmastanol, 3-methoxy-5, 6-dihydrostigmasterol, 7,8-dihydroergosterol, 4-methylcholesterol, cholestanol, multiflorenol, cholest-5-en-3-one, cholest-6-one, 5,6-dihydroergosterol, stigmasterol, dihydroalbigenin and 11-methyl-Δ^{5,7,9,15,17,23}-triacont-hex-ene were isolated from the petroleum ether extract. Methyl heptacosanoate and quinic acid ester of rhamnose were isolated from the ether fraction of the 70% ethanol extract. Antimicrobial activity of the total alcohol extract and the successive fractions showed that the ether and the ethyl acetate fractions have potent antibacterial activity against Bacillus subtilis and Bacillus cereus.ConclusionsThe ether and the ethyl acetate fractions could be used in pharmaceutical formulations as antibacterial agents against Bacillus subtilis and Bacillus cereus, and further clinical trials should be performed in order to support the above investigations.     

In vitro antioxidant activity and total phenolic content of endophytic fungi isolated from Eugenia jambolana Lam.

ObjectiveTo elucidate the antioxidant activity and total phenolic content (TPC) of ethyl acetate extracts of endophytic fungi isolated from Eugenia jambolana by three different antioxidant assays.MethodsTwenty one different endophytic fungal extracts were screened for presence of various phytochemicals, TPC and in vitro antioxidant activity. TPC was tested by Folin-Ciocalteau reagent based assay. DPPH free radical scavenging, hydrogen peroxide scavenging and reducing power assays were used to evaluate the antioxidant activity.ResultsAlkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all 21 endophytes. A significant positive correlation was found between antioxidant activity and TPC in fungal extracts. There is 36% endophytic extracts having high phenolic content exhibited potent antioxidant activity. Chaetomium sp., Aspergillus sp., Aspergillus peyronelii and Aspergillus niger strain showed the highest antioxidant activity ranging from 50% to 80% having 58 mg/g to 60 mg/g GAE total phenolics. Ascorbic acid used as a standard showed 90% reducing potential.ConclusionsThe results reveal that metabolites produced by endophytic fungi isolated from Eugenia jambolana can be a potential source of novel natural antioxidant compounds.     

Phytochemical analysis and in vitro antimicrobial activity of Illicium griffithii Hook. f. & Thoms extracts

ObjectiveTo evaluate the antimicrobial activity of hexane, ethyl acetate and methanol extracts of seeds and fruits of Illicium griffithii (I. griffithii)(Family: Schisandraceae).MethodsThe antimicrobial activity of the organic extracts were determined using disc diffusion assay against Gram-positive bacterial strains (three reference cultures and three clinical isolates), Gram-negative bacterial strains (nine reference cultures and six clinical isolates), and six fungi. The primary phytochemical and chemical compositions were analyzed using qualitative chemical analysis and gas chromatography-mass spectrometry respectively.ResultsEthyl acetate extract of fruits was effective against most of the tested reference cultures such as Staphylococcus aureus, Yersinia enterocolitica, Vibrio parahaemolyticus, Bacillus subtilis, Salmonella paratyphi, Enterococcus feacalis, Xanthomonas oryzae and Pseudomonas aerugenosa, whereas methanol extract showed activity only against Staphylococcus aureus, Bacillus subtilis and Xanthomonas oryzae. The hexane and ethyl acetate extracts of fruits were more effective against most of the clinical isolates, whereas methanol extract was effective only against Klebsiella pneumoniae ESBL. The extracts of fruits and seeds did not show any significant antifungal activity against tested fungi. The presence of phenols, tannins, flavonoids, triterpenoids, steroids, alkaloids, saponis and carbohydrates in the different extracts was established. Gas chromatography-mass spectrometry studies on hexane and ethyl acetate extract of fruits resulted in the identification of 31 and 39 compounds respectively.ConclusionsPotent antibacterial phytochemicals are present in ethyl acetate extract of I. griffithii fruits. Further studies are needed to investigate activities of I. griffithii against multidrug resistant bacteria.     

Phytochemical and biological activities of Bituminaria bituminosa L. (Fabaceae)

ObjectiveTo investigate the phytochemical composition, the antioxidant and antibacterial activities of Bituminaria bituminosa L. (Fabaceae) (B. bituminosa).MethodsThe aerial parts of B. bituminosa yielded two compounds. The structures of these compounds were determinated using UV, ¹H-NMR and ¹³C-NMR experiments and comparison of their spectroscopic properties with literature data. The antibacterial activity of the extracts (CH₂Cl₂, ethyl acetate and n-BuOH) was determinated using disk diffusion method against standard and clinical strains. Antioxidant potential of n-BuOH extract was evaluated through two methods: DPPH and cupric ion reducing antioxidant capacity assay.ResultsThe n-BuOH extract from B. bituminosa yielded the isolation of isoflavone and flavone. The extracts CH₂Cl₂, ethyl acetate and n-BuOH demonstrated significant antibacterial activities. CH₂Cl₂ extract showed the maximum antibacterial activity with high concentration of 2 mg/mL against Staphylococcus aureus ATCC 29213, Klebsiella pneumonia and Escherichia coli ATCC 25922 (20.45 mm, 16.41 mm and 15.74 mm inhibition zone, respectively). The value IC₅₀ was 0.26 μg/mL for n-BuOH extract using DPPH method. Whereas the E% value was 0.10 L/mg every centimeter for cupric ion reducing antioxidant capacity assay.ConclusionsThe phytochemical study of B. bituminosa revealed the presence of isoflavone (daidzin) and flavone (isoorientin) and identified for the first time in this specie. The antibacterial activity of the plant B. bituminosa is certainly related to its chemical content. The n-BuOH extract showed a significant antioxidant activity.     

Synthesis and antibacterial evaluation of 2–substituted–4,5–diphenyl–N–alkyl imidazole derivatives

ObjectiveTo synthesis 2–substituted–4,5–diphenyl–N–alkyl imidazole derivatives. and evaluate their antibacterial activity.MethodsA mixture of benzil (10 mmol) and ammonium acetate (0.1 mol) (immediately fused) in glacial acetic acid (25 mL) was stirred at 80–100 °C for 1 h under nitrogen atmosphere (to prevent incorporation of any atmospheric impurities and moisture). Substituted aldehydes (10 mmol) in glacial acetic acid (5 mL) was added drop-wise over a period of 15–20 min at the same temperature and stirred for another 4 h, the progress of the reaction was monitored by TLC test using ethyl acetate as eluent. The newly synthesized compounds were characterized by IR, ¹HNMR, ¹³CNMR and by mass spectroscopy.ResultsAll the synthesized compounds were confirmed by spectroscopical techniques and evaluated for antimicrobial activity against Staphylococcus aureus(S. aurius), Bacilus subtilus (B. subtilus), and Escheria coli (E. coli). These compounds showed antibacterial activity (zone of inhibition) against S. aurius ranged from 3 mm to 9 mmin diameter, B. subtilus, 4–8 mm, and E. coli 5–12 mm. Out of 2a-2e, only 2a and 2b showed some sort of activity but none of them had considerable activity compared with that of the standard.ConclusionsAll the synthesized compounds show moderate activity against the tested bacteria S. aurius, B. subtilus, and E. coli. So, further structural modification is necessary to improve the antibacterial action of 2-substituted-4,5-diphenyl-N-alkyl imidazole derivatives.     

Monitoring in vitro efficacy of Holarrhena antidysenterica against multidrug resistant enteropathogenic bacteria

ObjectiveTo assess antibacterial activities of leaf and bark extracts of Holarrhena antidysenterica (H. antidysenterica), used by an Indian aborigine for ailments of human gastrointestinal tract, against eight extended spectrum β-lactamase producing multidrug resistant enteropathogens.MethodsAntibacterial activities of eight solvent-extracts of the plant were monitored by the agar-well diffusion method on lawns of all bacteria. Further, minimum inhibitory concentrations and minimum bactericidal concentrations of the best three solvent extracts were determined by the micro-broth dilution method. Preliminary phytochemical analysis of the active leaf and bark extracts were carried out.ResultsIt was found that Enterobacter aerogenes was resistant to 14 of 16 antibiotics, likewise, Escherichia coli to 13, Klebsiella sp. to 14, Salmonella paratyphi to 7, Salmonella typhi to 15, Shigella dysenteriae and Shigella sonnei to 14, Vibrio cholerae to 4 of 16 antibiotics. It was found that plant-extracts with petroleum ether and n-hexane had the least antibacterial activity. Extracts of leaves with chloroform, methanol, and water registered moderate antibacterial activity, whereas bark-extracts with ethyl acetate, acetone, and ethanol had a comparatively higher antibacterial activity on all these strains. Maximum sizes of zone of inhibition due to leaf extracts with ethyl acetate, acetone, and ethanol, and on the other hand, bark extracts with ethyl acetate, acetone and methanol were recorded against these bacteria; minimum inhibitory concentration and minimum bactericidal concentration values of specifically these extracts were determined. Phytochemical analysis of the methanolic bark extract of H. antidysenterica confirmed the presence of alkaloids, terpenoids, reducing sugars, tannins, and flavonoids.ConclusionData analysis revealed that leaves and bark of H. antidysenterica could serve as complementary/supplementary drugs along with suitable antibiotics to control the marauding multidrug resistant enteropathogens.     

Anti-arthritis activity of roots of Hemidesmus indicus R.Br. (Anantmul) in rats

ObjectiveTo investigate the protective effects of hydroalcoholic and its fractions from roots of Hemidesmus indicus on arthritis in in vitro models of rodents.MethodsPreliminary phytochemical analysis and thin-layer chromoatography were performed to analyze constituents of hydroalcoholic extract and its three fraction namely ethyl acetate fraction, chloroform fraction and residual fraction of root of Hemidesmus indicus. Arthritis rats models were established by Complete Freund's Adjuvant. The parameters including paw edema, body weight, arthritic index, erythrocyte sedimentation rate, serum rheumatoid factor, serum C-reactive protein, serum nitrite level, and histopathology of synovial joints were observed. Methotrexate was taken as positive control.ResultsRats treated with hydroalcoholic extract (450 mg/kg, p.o.), ethyl acetate (75 mg/kg, p.o.), chloroform (60 mg/kg, p.o) and residual fractions (270 mg/kg, p.o.), showed significant decrease in physical and biochemical parameters compared with arthritic model rats. Hydroalcoholic extract and its ethyl acetate fraction of Hemidesmus indicus showed significantly higher anti-arthritic activity than chloroform and residual fraction. Histopathological analysis demonstrated that both of hydroalcoholic extract and its ethyl acetate fraction had comparable anti-arthritic activity with methotrexates.ConclusionsThe present study suggests that Hemidesmus indicus has protective activity against arthritis and the activity might be attributed to presence of terpenoid in hydroalcoholic extract, as well as in ethyl acetate fraction.     

Isolation and identification of bioactive antibacterial components in leaf extracts of Vangueria spinosa (Rubiaceae)

ObjectiveThe column chromatographic fraction of ethyl acetate (EA1, EA2, EA3, EA4 and EA5) leaf extracts of Vangueria spinosa (V. spinosa) were screened for antibacterial activity and phytochemical analysis.MethodsEA3 fraction was isolated and identified by column chromatography, thin layer chromatography, spectral data analysis and phytochemical screening were used for analysis.ResultsEA3 fraction was significantly active at 4 to 64 mg/L against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa with minimum inhibitory concentration of 1.5625 to 3.1250 mg/mL. The active fraction (EA3) revealed the presence of flavonoid with retention factor value (R_f) of 0.39. The active antibacterial agent in the most potent fraction (EA3) was isolated and identified as flavonoid (?)–epicatechin–3–O–β–glucopyranoside by thin layer chromatography (TLC) and phytochemical screening. EA1 and EA2 show inhibitory activity at 4 to 64 mg/L against Staphylococcus aureus only where as fraction EA4 and EA5 do not shows any inhibitory activity within that range of concentration against any bacteria.ConclusionsThe results support the ethnomedicinal use of leaf of V. spinosa for the treatment of bacterial diseases.     

Preliminary phytochemical analysis, antibacterial, antifungal and anticandidal activities of successive extracts of Crossandra infundibuliformis

ObjectiveTo investigate the phytochemical, antibacterial, antifungal and anticandidal activity of successive extracts of Crossandra infundibuliformis (Acanthaceae) leaves.MethodsPreliminary screening on the presence of alkaloids, saponins, phytosterols, phenolic compounds, flavanoids, tannins, carbohydrates, terpenoids, oils and fats were carried out by phytochemical analysis. The antibacterial, antifungal and anticandidal activities were done by agar well diffusion technique.ResultsThe successive extracts have an array of chemical constituents and the MIC values of antibacterial activity ranges from 0.007 8 to 0.015 0 μg/mL. In case of antifungal and anticandidal activities the MIC values were between 0.125 and 0.250 μg/mL.ConclusionsThese findings demonstrate that the leaf extracts of C. infundibuliformis presents excellent antimicrobial activities and thus have great potential as a source for natural health care products.     

An in vitro antibacterial and antifungal effects of cadmium(II) complexes of hexamethyltetraazacyclotetradecadiene and isomers of its saturated analogue

ObjectiveTo evaluate the antibacterial and antifungal effects of cadmium(II) complexes with hexamethyltetraazacyclotetradecadiene ligands.MethodsFive coordinated square pyramidal cadmium(II) complexes and six coordinated square octahedral cadmium(II) complexes have been synthesized by interaction of 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (denoted by L.2HClO₄) and C-chiral isomers of its saturated analogue (denoted by ‘teta’ and ‘tetb’) with different salts of Cd²⁺ ion [e.g. CdI₂, Cd(NO₃)₂·6H₂O, CdCl₂·2H₂O and Cd(ClO₄)₂·6H₂O] in methanolic solution. Complexes of the ligands were investigated for antibacterial activity by disc diffusion method and antifungal effect by poisoned food technique.ResultsThe newly synthesized cadmium(II) complexes of the ligands were screened as potential antimicrobial agent against a number of medically important bacteria (Staphylococcus aureus, Bacillus cereus, Salmonella typhi, Shigella dysenteriae and Escherichia coli) and against two fungi (Candida albicans and Aspergillus aculeatus). The growth inhibiting activity of the ligands and complexes against bacteria and fungi were compared with the standard antibiotic ampicillin and commercially important antifungal agent, griseofulvin respectively. Among them some of the macrocyclic complexes were found to be more fungitoxic and antibacterial than the reference antifungal drug griseofulvin and antibacterial drug ampicillin respectively.ConclusionsHexamethyltetraazacyclotetradecadiene ligands and its complexes could be considered as very potential antibacterial and antifungal agent with further investigation.     

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.     

Antioxidant activity and free radical scavenging activities of Streptomyces sp.strain MJM 10778

Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS radical scavenging activity in ethyl acelale extract were determined.Results:The 16 S rDNA sequencing analysis revealed that Streptomyces sp.strain MJM 10778.which was isolated from Hambak Mountain.Korea,has 99.9% similarity to Streptomyces misionensis(S.misionenis) NBRC 13063.The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC.13063.The entire antioxidant assay with the ethyl acelale extract displayed good radical scavenging activity.The IC_(50) values of the strain MJM 10778 extract on DPPH,.NO.and ABTS radicals were identified to he 92.8 μg/mL,0.02 μg/ml,and 134.9 μg/mL,respectively.The ethyl acetate extract of the strain MJM 10778 showed an 81.500% of cell viability at 100 μg/mL in Raw264.7cell viability assay.Conclusions:The results obtained suggesl that the ethyl acetate extract of Streptomyces sp.strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.     

Antioxidant activity and identification of bioactive compounds from leaves of Anthocephalus cadamba by ultra–performance liquid chromatography/electrospray ionization quadrupole time of flight mass spectrometry

ObjectiveTo evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba (A. cadamba) (Roxb.) Miq. (Rubiaceae) and study the tentative identification of their active constituents.MethodsThe extract/fractions were screened for antioxidant activity using various in vitro assays viz. DPPH assay, ABTS assay, superoxide anion radical scavenging assay, reducing power assay and plasmid DNA nicking assay. Total phenolic content of extract/fractions was determined by colorimetric method. An ultra–performance LC-electrospray-quadrupole-time of flight mass spectrometry method was used to analyse the active constituents of extract/fractions of A. cadamba.ResultsThe ethyl acetate fraction was found to be most active fraction in all the assays as compared to other extract/fractions. The IC₅₀ value of ethyl acetate fraction (ETAC fraction) was 21.24 μg/mL, 1.12 μg/mL, 9.68 μg/mL and 57.81 μg/mL in DPPH assay, ABTS assay, reducing power assay and superoxide scavenging assay respectively. All the extract/fractions also showed the potential to protect the plasmid DNA (pBR322) against the attack of hydroxyl radicals generated by Fentońs reagent. The bioactive compounds were identified by UPLC-ESI-QTOF-MS, by comparing the mass and λ_max with literature values.ConclusionsThe potential of the extract/fractions to scavenge different free radicals in different systems indicated that they may be useful therapeutic agents for treating radical-related pathologic damage.     

In vitro antiplasmodial activity of Clathria vulpina sponge associated bacteria against Plasmodium falciparum

ObjectiveTo identify the possible antiplasmodial drugs from bacteria associated with marine sponge Clathria vulpina (C. vulpina).MethodsThe C. vulpina samples were collected from Thondi coast and subjected to enumeration and isolation of associated bacteria. Filtered and sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg/mL) from isolated bacterial strains were screened for antiplasmodial activity against Plasmodium falciparum. Potential extracts were also screened for biochemical constituents.ResultsThirty one bacterial strains were isolated from twelve sponge samples collected from Thondi coast and screened for antiplasmodial assay. The count of bacterial strains were maximum in November 2007 (19×10⁴ CFU/g) and the average count was maximum during the monsoon season (110×10³ CFU/g). The antiplasmodial activity of strain THB15 was highly comparable (IC₅₀ = 20.73 μg/mL) with the positive control chloroquine (IC₅₀ = 19.59 μg/mL) and 21 bacterial strains 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 bacterial strains after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of sugars and alkaloids in the ethyl acetate extracts of bacterial strains.ConclusionThe ethyl acetate extract of THB15 possesses lead compounds for the development of antiplasmodial drugs.     

Antagonistic properties of seagrass associated Streptomyces sp. RAUACT-1: A source for anthraquinone rich compound

ObjectiveTo identify the antibacterial potential of seagrass (Syringodium isoetifolium) associate microbes against bacterial pathogens.MethodsEumeration of microbial associates were analyzed with leaf and root samples of Syringodium isoetifolium. MIC and MBC were calculated for bacterial pathogens with microbial associates. Phylogenetic and GC-MS analysis were calculated for Actinomycetes sp. (Act01) which was the most potent.ResultsOf the isolated microbial associates phosphatase producing bacterial isolates were identified as maximum [(261.78±35.09) CFU×10⁴/g] counts in root sample. Of the selected microbial isolates Actinomycete sp (Act01) showed broad spectrum of antibacterial activity against antibiotic resistant and fish bacterial pathogens. Phylogenetic analysis of Act01 showed maximum identities (99%) with the Streptomyces sp. (GU5500072). The 16s rDNA secondary structure of Act01 showed the free energy values as ?366.3 kkal/mol. The GC-MS analysis Act01 showed maximum retention value with 23.742 RT and the corresponding chemical class was identified as 1, 4-dihydroxy-2-(3-hydroxybutyl)-9, 10-anthraquinone 9, 10-anthrac.ConclusionsIn conclusion, Streptomyces sp. (GU045544.1) from Syringodium isoetifolium could be used as potential antibacterial agent.     

Antibacterial activity of ethyl acetate and aqueous extracts of Mentha longifolia L. and hydroalcoholic extract of Zataria multiflora Boiss. plants against important human pathogens

ObjectiveTo determine the potential antibacterial activity of ethyl acetate and aqueous extracts from Mentha longifolia L. (M. longifolia) and hydroalcoholic extract of Zataria multiflora Boiss. (Z. multiflora) against important human pathogens.MethodsPseudomonas aeruginosa, Shigella dysenteriae, Klebsiella pneumoniae (K. pneumonia), Enterobacter cloacae, Salmonella typhi, Proteus mirabilis, Serratia marcescens, Bacillus cereus, Staphylococcus saprophyticus and Staphylococcus aureus were kinds of pathogenic bacteria to determine the antibacterial effect of aqueous and ethyl acetate extracts of M. longifolia and hydroalcoholic extract of Z. multiflora using broth microdiluation method.ResultsThe lowest minimum inhibitory concentration and minimum bactericidal concentration values for K. pneumonia and Pseudomonas aeruginosa (1.25 and 2.5 mg/mL) were observed by the hydroalcoholic extract of Z. multiflora and the lowest minimum inhibitory concentration and minimum bactericidal concentration values for K. pneumonia and Serratia marcescens (2.5 and 5 mg/mL) were observed by the aqueous extracts of M. longifolia.ConclusionsIn conclusion, it seems that Z. multiflora and M. longifolia extracts could inhibit the growth of all of the mentioned bacteria.     

Evaluation of wound healing and antimicrobial potentials of Ixora coccinea root extract

ObjectiveTo evaluate the wound healing and antimicrobial activity of root extracts of Ixora coccinea (I. coccinea).MethodsTo investigate the wound healing efficacy of root extract of I. coccinea Linn, five groups of animals were divided each containing six animals. Two wound models including incision and excision wound models were used in this study. The parameters studied were tensile strength on incision wound model and in terms of wound contraction for excision wound model were compared with standard Nitrofurazone (NFZ) ointment (0.2% w/w). Six extracts (ethanol, aqueous, petroleum ether, benzene, chloroform and ethyl acetate) of I. coccinea were screened for in vitro growth inhibiting activity against different bacterial strains viz, Staphylococcus aureus, Bacillus pumilius, Enterococcus faecalis, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa and fungi Candida albicans and Aspergillus niger were compared with the standard drugs ciprofloxacin and chloramphenicol for antibacterial and griseofulvin for antifungal screening. The serial dilution and cup (or) well plate methods were used for the antimicrobial study and MIC was determined.ResultsThe ethanolic extract showed significant (P<0.001) wound healing activity when compared to standard drug NFZ with respect to normal control group. Amongst all, ethanolic extract showed highly significant antibacterial activity against all bacterial strains used in this study when compared to standard. The aqueous extract showed moderate significant inhibition against all bacterial strains when compared to standard. All the extracts were shown negligible activity against the fungal strains used in this study.ConclusionsThe ethanolic root extract of I. coccinea showed pronounced wound healing and antibacterial activity. The probable reason to heal the wound was that the external application of the extract prevented the microbes to invade through the wound thus the protection of wound occurs against the infection of the various organisms.