Characterization of biofilm formed by multidrug resistant Pseudomonas aeruginosa DC-17 isolated from dental caries.

The present work reports with the screening of biofilm-producing bacteria from the dental caries. The dental pathogens showed resistance against various antibiotics and biofilm forming ability at various levels. Among the bacterial strain, Pseudomonas aeruginosa DC-17 showed enhanced biofilm production. Extracellular polymeric substance (EPS) was synthesized by the selected bacterial isolate considerably and contributed as the major component of biofilm. EPS composed of eDNA, proteins and lipids. The total protein content of the EPS was found to be 1.928 mg/mL and was the major component than carbohydrate and DNA. Carbohydrate content was 162.3 mg/L and DNA content of EPS was 4.95 µg/mL. These macromolecules interacted in the matrix to develop dynamic and specific interactions to signalling biofilm to differentiating various environments. Also, the isolated bacteria showed resistant against various commercially available antibiotics. The isolates showed more resistance against penicillin (98%) and were sensitive against amoxicillin. Among the factors, temperature, pH and sugar concentration influenced biofilm formation. Biofilm forming ability of the selected bacterial stain was tested at various pH values and alkaline pH was favoured for biofilm production. Biofilm production was found to be maximum at 40 °C and 8% sucrose enhanced biofilm formation. Biofilm formed by P. aeruginosa DC-17 was resistant against various tested antimicrobials and chemicals.

Green synthesis of silver nanoparticles using aqueous rhizome extract of Zingiber officinale and Curcuma longa: In-vitro anti-cancer potential on human colon carcinoma HT-29 cells.

This study was aimed to analyze the anti-cancer activity of silver nanoparticles (AgNPs) synthesized using aqueous plant extracts from the rhizome of Curcuma longa and Zingiber officinale. Synergistic aqueous extract of rhizome of C. longa and Z. officinale was used to green synthesis of AgNPs. Characterization of AgNPs was performed using UV-visible spectroscopy, FTIR, X-ray diffraction, TEM, and SEM analyses. Anti-cancer activity of AgNPs against human colon carcinoma (HT-29) cells was tested using MTT assay. UV-Visible spectroscopy analysis indicated the surface plasmon resonance (SPR) sharp peak at 350-430 nm wavelength that corresponds to the production of AgNPs. FTIR analysis reveals that existence of carboxyl (-C[bond, double bond]O) and amine (N-H) functional groups in the AgNPs. The X-ray diffraction analysis confirms four spectral peaks at 111, 200, 220, and 311. SEM analysis showed that AgNPs are in a spherical shape with a size of 42-61 nm and TEM analysis showed particle size are ranged between 20-51 nm. Anti-cancer study reveals that AgNPs had shown cytotoxicity against HT-29 cells at the concentrations ranged from 25 to 500 µg/mL and IC50 at 150.8 µg/mL. This study concludes that AgNPs synthesized using rhizome of Z. officinale and C. longa possesses potential anti-cancer activity.

Identification of phytochemical components from Aerva lanata (Linn.) medicinal plants and its in-vitro inhibitory activity against drug resistant microbial pathogens and antioxidant properties.

This study aimed to determine the phytochemical components, microbial inhibitory effectiveness and antioxidant properties of Aerva lanata plant extracts. The whole plant showed various medicinal applications in folklore and traditional medicine in various parts of the world. The organic extracts such as ethanol, ethyl acetate, chloroform, acetone, water and methanol were subjected for various phytochemical analysis and confirmed for the existence of flavonoids, glycosides, terpenoids and alkaloid containing components. Alternatively, the extracts were performed for the antibacterial activities against the microbial pathogens and antioxidant properties. Results indicated that, the solvent extracts showed prominent activity against the tested strains. The MIC concentrations of plant were detected from 5 mg/ml to 40 mg/ml. The plant extract was highly effective against E. coli and E. aerogenes and the MIC was 5 mg/ml. In addition, the extracts noted promising antioxidant activities. The antioxidant activities were dose dependent manner. In conclusion, A. lanata extracts showed that significant major phytochemicals and effective antioxidant and anti-microbial properties.

In vitro Antibacterial Activity of Aqueous and Ethanol Extracts of Aristolochia indica and Toddalia asiatica Against Multidrug-Resistant Bacteria.

Bacteria have developed multidrug resistance against available antimicrobial agents. Infectious diseases caused by these multidrug-resistant bacteria are major causes of morbidity and mortality in human beings. Synthetic drugs are expensive and inadequate for the treatment of diseases, causing side effects and ineffective against multidrug-resistant bacteria. The medicinal plants are promising to have effective antimicrobial property due to presence of phytochemical compounds like alkaloids, flavanoids, tannins and phenolic compounds. The present study aimed to find the antimicrobial activity of medicinal plants against multidrug-resistant bacteria. Multidrug-resistant bacteria were identified by Kirby-Bauer disc diffusion method. Production of ß-lactamases (extended spectrum ß-lactamases, metallo ß-lactamase and AmpC ß-lactamase) were identified by combination disc method. Antibacterial activity of aqueous and ethanol extract of Aristolochia indica and Toddalia asiatica were detected by agar well diffusion assay and minimum inhibitory concentration. All bacteria used in this study showed antibiotic resistance to ≥3 antibiotics. Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Vibrio cholerae were found to be positive for ß-lactamase production. Ethanol extract of Aristolochia indica showed more significant antibacterial activity against multidrug-resistant bacteria than Toddalia asiatica. Ethanol extracts of Aristolochia indica and Toddalia asiatica showed minimum inhibitory concentration values of 50-100 µg/ml and 100-200 µg/ml, respectively against multidrug-resistant bacteria. From this study, it was concluded that Aristolochia indica has more potential to treat multidrug-resistant bacteria than Toddalia asiatica.

α-Glucosidase inhibition and antioxidant properties of Streptomyces sp.: in vitro.

Streptomyces strain isolated from the soil sediment was studied for its in vitro α-glucosidase and antioxidant properties. Morphological characterization and 16S rRNA partial gene sequencing were carried out to confirm that the strain Loyola AR1 belongs to genus Streptomyces sp. Modified nutrient glucose broth was used as the basal medium for growth and metabolites production. Ethyl acetate extract of Loyola AR1 (EA-Loyola AR1) showed 50% α-glucosidase inhibition at the concentration of 860.50 ± 2.68 µg/ml. Antioxidant properties such as total phenolic content of EA-Loyola AR1 was 176.83 ± 1.17 mg of catechol equivalents/g extracts. EA-Loyola AR1 showed significant scavenging activity on 2,2-diphenyl-picrylhydrazyl (50% inhibition (IC50), 750.50 ± 1.61 µg/ml), hydroxyl (IC50, 690.20 ± 2.38 µg/ml), nitric oxide (IC50, 850.50 ± 1.77 µg/ml), and superoxide (IC50, 880.08 ± 1.80 µg/ml) radicals, as well as reducing power. EA-Loyola AR1 showed strong suppressive effect on lipid peroxidation (IC50, 670.50 ± 2.52 µg/ml). Antioxidants of ß-carotene linoleate model system reveals significantly lower than butylated hydroxyanisole.

Spectral detection of sickle cell anemia and thalassemia.

Sickle cell disease (SCD) and thalassemia (Thal) are the most common inherited, autosomal, recessive blood disorders which lead to complications such as vasoocclusion and splenomegaly. Patients who suffer from these diseases have poor quality of life and shorter life span. The most common techniques for detection of these diseases are complete blood cell count, followed by electrophoresis and high performance liquid chromatography. In this connection, the results of this paper indicate the potential of a new technique, based on spectral analysis of blood plasma and cellular components, to detect SCD and Thal with accuracy of 90% and above. To the best of our knowledge this would be the first report on spectral pathology of hemoglobinopathy.

In vitro studies on α-glucosidase inhibition, antioxidant and free radical scavenging activities of Hedyotis biflora L.

Aim of this study was to evaluate the in vitro α-glucosidase inhibition and antioxidant activity of hexane, ethyl acetate and methanol extracts of Hedyotis biflora L. (Rubiaceae). In in vitro α-glucosidase inhibition and antioxidant activity, the methanol extract showed potent effect compared to hexane and ethyl acetate extracts. The methanol extract of H. biflora (HBMe) showed 50% α-glucosidase inhibition at the concentration of 480.20 ± 2.37 µg/ml. The total phenolic content of HBMe was 206.81 ± 1.11 mg of catechol equivalents/g extract. HBMe showed great scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC(50) 520.21 ± 1.02 µg/ml), hydroxyl (IC(50) 510.21 ± 1.51 µg/ml), nitric oxide (IC(50) 690.20 ± 2.13 µg/ml) and superoxide (IC(50) 510.31 ± 1.45 µg/ml) radicals, as well as high reducing power. HBMe also showed a strong suppressive effect on lipid peroxidation. Using the ß-carotene method, the scavenging values of HBMe was significantly lower than BHT, and metal chelating ability of HBMe also showed a strong inhibition effect when compared to the reference standard. The active compound ursolic acid from HBMe was identified using various spectroscopical studies. The results obtained in this study clearly indicate that HBMe has a significant potential to use as a natural α-glucosidase inhibition, antioxidant agent.

In vitro α-glucosidase inhibition and antioxidative potential of an endophyte species (Streptomyces sp. loyola UGC) isolated from Datura stramonium L.

Endophytic actinomycetes isolated from Datura stramonium L. was evaluated for its effects against in vitro α-glucosidase inhibition, antioxidant, and free radical scavenging activities. Based on microbial cultural characteristic and 16S rRNA sequencing, it was identified as Streptomyces sp. loyola UGC. The methanolic extract of endophytic actinomycetes (MeEA) shows remarkable inhibition of α-glucosidase (IC50 730.21 ± 1.33 µg/ml), scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC50 435.31 ± 1.79 µg/ml), hydroxyl radical (IC50 350.21 ± 1.02 µg/ml), nitric oxide scavenging (IC50 800.12 ± 1.05 µg/ml), superoxide anion radical (IC50 220.31 ± 1.47 µg/ml), as well as a high and dose-dependent reducing power. The MeEA also showed a strong suppressive effect on rat liver lipid peroxidation. Antioxidants of ß-carotene linoleate model system revels significantly lower than BHA. The total phenolic content of the extract was 176 mg of catechol equivalents/gram extract. Perusal of this study indicates MeEA can be used as natural resource of α-glucosidase inhibitor and antioxidants.

Antimicrobial activity of Ulopterol isolated from Toddalia asiatica (L.) Lam.: a traditional medicinal plant.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Toddalia asiatica (L.) Lam. (Rutaceae) are widely used in folk medicine in India to treat various ailments like cough, malaria, indigestion, influenza lung diseases and rheumatism, fever, stomach ailments, cholera and diarrhea. In our earlier communication we have reported the antimicrobial study on the various extracts of the leaves and the isolation and identification of Flindersine, a quinolone alkaloid as the major active principle. In the present study, we report the antibacterial and antifungal activities of Ulopterol, a coumarin isolated as another major active antimicrobial principle. MATERIALS AND METHODS: The leaves were successively extracted with hexane, chloroform, ethyl acetate, methanol and water. The extracts were studied for their antimicrobial activity against selected bacteria and fungi by using disc-diffusion method. The ethyl acetate extract which was found to possess highest antimicrobial activity was subjected to activity guided fractionation by column chromatography over silica gel. This resulted in the isolation of the coumarin, Ulopetrol, an active principle besides Flindersine which was reported by us earlier. The structure of the compound was elucidated using physical and spectroscopic data. Flindersine and Ulopterol were quantified by HPLC. RESULTS: Ulopterol showed activity against the bacteria viz. Staphylococcus epidermidis, Enterobacter aerogenes, Shigella flexneri, Klebsiella pneumoniae (ESBL-3967), Escherichia coli (ESBL-3984) and fungi viz. Aspergillus flavus, Candida krusei and Botrytis cinerea. Quantification by HPLC showed the content of Flindersine and Ulopterol to be 0.361% and 0.266% respectively on dry weight basis of the leaves. CONCLUSIONS: Ethyl acetate extract (successive extraction) contained Ulopterol, a coumarin, besides Flindersine, a quinolone alkaloid, as a major active principle in the antimicrobial studies. This is the first report of the antimicrobial activity of Ulopterol and also its first report from the plant.

Characterization and phylogenetic analysis of novel polyene type antimicrobial metabolite producing actinomycetes from marine sediments: Bay of Bengal, India.

OBJECTIVE: To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andrapradesh coast of India. METHODS: Antagonistic actinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1% glucose used as a base for primary screening. Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level. Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method. RESULTS: Among the 210 actinomycetes, 64.3% exhibited activity against Gram positive bacteria, 48.5 % showed activity towards Gram negative bacteria, 38.8% exhibited both Gram positive and negative bacteria and 80.85 % isolates revealed significant antifungal activity. However, five isolates AP-5, AP-18, AP-41 and AP-70 showed significant antimicrobial activity. The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates. Sequencing analysis indicated that the isolates shared 98.5%-99.8% sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons. The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30°Cfor five days. The antimicrobial activity was assessed using broth micro dilution technique. Each of the culture extracts from these five strains showed a typical polyene-like property. The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Curvularia lunata were 67.5 and 125.0 µg/mL, respectively. CONCLUSIONS: It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.

Partial regeneration of beta-cells in the islets of Langerhans by Nymphayol a sterol isolated from Nymphaea stellata (Willd.) flowers.

Reduction of the beta-cell mass is critical in the pathogenesis of diabetes mellitus. The discovery of agents which induce regeneration of pancreatic beta-cells would be useful to develop new therapeutic approaches to treat diabetes. The present study was aimed at identifying a new agent for the control of diabetes through regeneration of pancreatic beta cells and insulin secretory potential. Nymphaea stellata flower chloroform extract (NSFCExt) showed significant plasma glucose lowering effect. Further NSFCExt was utilized to isolate and identify the lead compound based on bioassay guided fractionation; we found Nymphayol (25,26-dinorcholest-5-en-3beta-ol) a new crystal [space group P2(1) (No. 4), a=9.618(5), b=7.518(5), c=37.491(5)]. It was purified by repeat column. The structure was determined on the basis of X-ray crystallography and spectral data. Oral administration of Nymphayol for 45 days significantly (p<0.05) lowered the blood glucose level and more importantly it effectively increased the insulin content in diabetic rats. In addition, Nymphayol increased the number of beta cell mass enormously. Islet-like cell clusters in the islets of Langerhans were clearly observed based on histochemical and immunohistochemical study.

Insulin secretagogue effect of Ichnocarpus frutescence leaf extract in experimental diabetes: a dose-dependent study.

Ichnocarpus frutescence (L.) R.Br. is an evergreen plant and many preparations have been used in traditional Indian medicine for centuries to treat several illnesses including diabetes. However, scientific evidence supporting these actions is lacking. In the present study we prepared various extracts of I. frutescence (IF) leaves which were tested against streptozotocin-induced diabetic rats. IF leaf methanolic extract (IFLMExt) showed significant plasma glucose lowering effect. Therefore, we prepared IFLMExt, which was tested against different types of glycemia (normal, glucose-fed hyperglycemic and streptozotocin-induced diabetic rats) for their potential to induce insulin secretion and cellular insulin responses. Fasting plasma glucose (FPG) levels were determined at different doses and times following treatment with IFLMExt or with vehicle in normal, glucose fed-hyperglycemic and diabetic rats. Oral administration of IFLMExt led to a significant blood glucose-lowering effect in glucose-fed hyperglycemic and diabetic rats. The hypoglycemic effect was observed at doses of 100 and 200 mg/(kg bw) after 6 and 2 h administration, respectively, in glucose-fed hyperglycemic rats. The maximum effect of IFLMExt was detected at 2 h with 200 mg/(kg bw) in diabetic animals and this profile was maintained for the next 6 h (37.23%) but increased after that at 24 h. Oral administration of IFLMExt daily for 45 days to diabetic rats significantly reduced the FPG (54.5%) to near normal. After 7 days of streptozotocin administration plasma insulin decreased in diabetic controls compared to normal controls. Treatment with IFLMExt significantly prevented the decrease in plasma insulin levels from day 0 to 45 in comparison to diabetic controls. Oral administration of n-hexane fraction led to a significant glucose-lowering effect in diabetic rats (54.50%). Histopathological examination showed that IFLMExt extract protected the pancreatic tissue from streptozotocin-induced damage enormously. Oral administration of IFLMExt extract and n-hexane fraction to normal and streptozotocin-induced diabetic rats decreased plasma glucose levels without hypoglycemic effect. The results suggest that methanolic extract and n-hexane fraction of IF may provide new therapeutic avenues against diabetes.