Biosynthesis and Characterization of a Novel Fibrinolytic Alkaline Serine Protease from Newly Isolated Bacillus flexus BF12 for Biomedical Applications

BACKGROUND

Cardiovascular Diseases (CVDs) such as stroke, high blood pressure, peripheral vascular disease, ischemic heart disease and acute myocardial infarction are some of the leading causes of death. To treat CVDs, commercially available thrombolytic agents are widely used. However, these thrombolytic agents have various side effects. Alternatively, fibrinolytic enzymes from bacterial sources are highly safe and have direct blood clot lytic activity.

METHODS

A fibrinolytic enzyme producing bacterial strain, Bacillus flexus BF12, was isolated from a solar saltpan in Kanyakumari District, Tamilnadu, India. Enzyme production was improved by optimizing physical factors and nutritional factors.

RESULTS

A novel fibrinolytic enzyme was isolated from a strain of the studied B. flexus BF12. Enzyme production was enhanced significantly by optimizing process parameters. The critical physical factors (pH and salinity) and influencing nutritional factors (carbon, nitrogen and ions) were optimized by one variable at a time approach, followed by the statistical method. The strain BF12 was highly active at alkaline pH (>7.0) and between 4 and 6% NaCl concentration. The nutrients such as fructose (carbon source), beef extract (nitrogen source) and CaCl₂ significantly influenced enzyme production. Central composite design and response surface methodology improved 3.2-fold enzyme yield than unoptimized culture medium. Fibrinolytic protease was purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography.

DISCUSSION

The molecular weight of an enzyme was found to be 23 kDa. It was active at a broad temperature (40-60 °C) and pH (7.0-9.0) ranges. Enzyme activity was enhanced by Ca²⁺ and Co²⁺ ions. The purified protease retained 100% enzyme activity in the presence of ethanol and acetone. Acetonitrile, butanol, DMSO, methanol and chloroform showed enzyme activity of 63%, 92.5%, 94.7%, 92.3% and 90.4%, respectively. The purified enzyme degraded 100% of human blood clot.

CONCLUSION

The Bacillus flexus BF12 fibrinolytic enzyme shows promising potentials in nutraceutical and food fortification applications. The application of fibrinolytic enzymes could prevent CVDs.

In vitro antioxidant and cytotoxic activities of polyherbal extracts from Vetiveria zizanioides, Trichosanthes cucumerina, and Mollugo cerviana on HeLa and MCF-7 cell lines

Various metabolites exist in the medicinal plants have lot of potential to cure various diseases and disorders. Plants such as, Vetiveria zizanioides, Trichosanthes cucumerina, and Mollugo cerviana were collected from Western Ghats, Tamilnadu, India. Phytochemicals were extracted from these plants using various organic solvents and tested against Gram-positive and Gram-negative bacteria. The phytochemicals such as, carbohydrate, alkaloids, steroids, saponins, flavonoids and tannin were detected from these medicinal plants. Among the extracts, methanol showed potent activity and this solvent was used to extract polyherbal medicinal plants. Methanol extract of V. zizanioides was found to be highly active against E. coli (27 ± 2 mm), P. mirabilis (19 ± 3 mm) and B. subtilis (18 ± 2 mm). Ethyl acetate extract showed high activity against E. coli (24 ± 2 mm), P. mirabilis (22 ± 3 mm) and B. subtilis (20 ± 1 mm). These three plants were taken at 1:1:1 ratio and extracted with methanol at 1:10 ratio and synergistic activity was tested against bacterial pathogens. Synergistic activity of polyherbal extract was analyzed. The extracted crude herbal medicine was found to be effective against Staphylococcus aureus, E. coli, Enterbacter sp., Pseudomonas aeruginosa, Bacillus subtilis and Proteus mirabilis. The zone of inhibition was 33 ± 3 mm, 17 ± 2 mm, 22 ± 2 mm, 40 ± 2 mm, 33 ± 1 mm and 38 ± 2 mm zone of inhibition against E. coli, S. aureus, P. aeruginosa, P. mirabilis, B. subtilis and Enterobacter sp. Polyherbal extract was found to be highly effective against P. mirabilis and Enterobacter sp. MIC values of polyherbal extract ranged from 29 ± 2.5 µg/ml to 34 ± 2.5 µg/ml. MIC value was found to be less against P. mirabilis and was high against S. aureus. Antioxidant property varied between 49 ± 3% and 95.3 ± 2%. At 20 µg/ml antioxidant activity was reported as 49 ± 3% and it was increased at higher concentrations of polyherbal extract. Two cell lines (HeLa and MCF cell lines) were selected to analyze cytotoxic activity of polyherbal extract. The methanol extract of polyherbal fraction showed cytotoxicity against these two cell lines. The LC50 value was 467 ± 2.9 µg/ml against HeLa cell line and >800 µg/ml against MCF-7 cell lines. The polyherbal extract showed antibacterial, antioxidant and anticancer activities.

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.

Insights of antidiabetic, anti-inflammatory and hepatoprotective properties of antimicrobial secondary metabolites of corm extract from Caladium x hortulanum

Medicinal plants have therapeutic potential and are used worldwide to treat various diseases. In this study, the corm of Caladium x hortulanum was extracted with various solvents and implied the availability of phytochemicals such as flavonoids, alkaloids, tannins, steroids, phenols, glycosides, saponins and terpenoids. The solvent extracts of the corm showed antibacterial and antifungal activity with the growth inhibition zone ranged 0-24 mm. The isolation of phytochemicals was carried out using gel column chromatography, Thin Layer Chromatography followed by High Performance Liquid Chromatography. Gas Chromatography and Mass Spectrophotometry analysis was used to determine the phytochemicals. The corm extract showed potent antidiabetic activity on Hep G2 cell lines and CCl4 induced toxicity was elucidated. This possessed antiinflammatory property on murine monocyclic macrophage cell line RAW 264.7 showed 45.85 ± 1.8% inhibition of cyclooxygenase activity. The corm extract showed hepatoprotective activity. The CCl4 incorporated Hep G2 cells showed 19.629 ± 1.5% viability, whereas viability increased as 78.82 ± 1.9% at 100 µg/ml of extract.

Solid-substrate bioprocessing of cow dung for the production of carboxymethyl cellulase by Bacillus halodurans IND18

The production of carboxymethyl cellulase (CMCase) by Bacillus halodurans IND18 under solid substrate fermentation (SSF) using cow dung was optimized through two level full factorial design and second order response surface methodology (RSM). The central composite design (CCD) was employed to optimize the vital fermentation parameters, such as pH of the substrate, concentration of nitrogen source (peptone) and ion (sodium dihydrogen phosphate) sources in medium for achieving higher enzyme production. The optimum medium composition was found to be 1.46% (w/w) peptone, 0.095% (w/w) sodium dihydrogen phosphate and pH 8.0. The model prediction of 4210IU/g enzyme activity at optimum conditions was verified experimentally as 4140IU/g. The enzyme was active over a broad temperature range (40-60±1°C) and pH (7.0-9.0) with maximal activity at 60±1°C and pH 8.0. This study demonstrated the potential of cow dung as novel substrate for CMCase production.

A low cost fermentation medium for potential fibrinolytic enzyme production by a newly isolated marine bacterium, Shewanella sp. IND20

Agro-residues were used as the substrate for the production of fibrinolytic enzyme in solid state fermentation. In this study, two-level full factorial design (2⁵) and response surface methodology were applied to optimize a fermentation medium for the production of fibrinolytic enzyme from the marine isolate Shewanella sp. IND20. The 2⁵ factorial design demonstrated that the physical factors (pH and moisture) and nutrient factors (trehalose, casein, and sodium dihydrogen phosphate) had significant effect on fibrinolytic enzyme production. Central composite design was employed to search for the optimal concentration of the three factors, namely moisture, pH, and trehalose, and the experimental results were fitted with a second-order polynomial model at 99% level (p < 0.0001). The optimized medium showed 2751 U/mL of fibrinolytic activity, which was 2.5-fold higher than unoptimized medium. The molecular weight of fibrinolytic enzyme was found to be 55.5 kDa. The optimum pH and temperature were 8.0 and 50 °C, respectively.

Bioassay guided fractionation and identification of active anti-inflammatory constituent from Delonix elata flowers using RAW 264.7 cells

CONTEXT

Delonix elata (L.) Gamble (Fabaceae) has been used in the Indian traditional medicine system to treat rheumatism and inflammation.

AIM

To assess the anti-inflammatory effect of Delonix elata flowers and to isolate the active principle.

MATERIALS AND METHODS

The prompt anti-inflammatory constituent was isolated from Delonix elata flower extracts using bioassay guided fractionation in liposaccharide (LPS) stimulated RAW 264.7 macrophage cell line. The anti-inflammatory activity of extracts/fractions/sub-fractions/compounds (10, 25, and 50 µg/ml) was evaluated by estimating the levels of nitric oxide (NO), TNF-α, and IL-1β after 24 h of LPS induction (1 μg/ml). The isolated active compound was subjected to NMR, IR, and UV analyses for structure determination.

RESULTS

In an attempt to search for anti-inflammatory constituents, the active pure principle was isolated and crystallized as a white compound from Delonix elata flowers methanol extract. This active compound (50 µg/ml) decreased the release of inflammatory mediators levels such as NO (0.263 ± 0.03 µM), TNFα (160.20 ± 17.57 pg/ml), and IL-1β (285.79 ± 15.16 pg/ml) significantly (p < 0.05); when compared to the levels of NO (0.774 ± 0.08 µM), TNFα (501.71 ± 25.14 pg/ml), and IL-1β (712.68 ± 52.25 pg/ml) from LPS-stimulated macrophage cells. The active compound was confirmed as hesperidin with NMR, IR, and UV spectroscopy data. This is the first report of this compound from Delonix elata flowers.

CONCLUSION

The findings of the study support the traditional use of Delonix elata flowers to treat inflammation.

Modeling customer support performance in Indian IT hardware industry

Purpose

Customer support assumes strategic importance in India for branded IT‐hardware products. An authorized service center and a stream of specialized service centers undertake field services and represent a sale‐territory's support network. “Time constrained” service men have to deliver customized service meeting a promised time‐standard. The stochastic demand for support services severely mars the customer response resulting in poor service quality. A manufacturer has to address the following decisions under these conditions: what is the ideal staffing level in a territory considering restricted server availability? What will be the impact of changing the staffing levels on customer service level? This study develops an analytical model to address these decisions.

Design/methodology/approach

The study identifies the variables underlying stochastic service demand through a field survey and determines the demand distribution. Applying stochastic principles the study derives relation between field staffing level and customer response considering server time constraint. Study performs statistical analysis to validate this model with real time data on variables collected from the field survey.

Findings

The outcomes of analysis reveal the following findings: this model can be applied in service systems where a time constrained server has to deliver expected level of performance (research implication); and increasing field staffing levels obscures the significant difference between the customer waiting times under very high levels of uncertain demand (practical implication).

Originality/value

The study derives relation between the staffing levels and customer waiting time considering uncertain demand with restricted working hour conditions.

Dynamic changes of endothelin-1, nitric oxide, and cyclic GMP in patients with congenital heart disease

BACKGROUND

Pulmonary hypertension causes major morbidity and mortality after congenital heart surgery, but its mechanism remains unclear.

METHODS AND RESULTS

Plasma endothelin-1 (ET-1), nitric oxide (NO), and cyclic GMP (cGMP) were assayed at 6 intervals in 50 children undergoing cardiopulmonary bypass (CPB): before CPB, 10 minutes into CPB, and 0, 3, 6, and 12 hours after CPB. Three groups based on pulmonary flow and pressure were analyzed: low flow (LF, n=21), high flow/low pressure (systolic pulmonary pressure/systemic pressure ratio, Pp/Ps<50%, HF-LP, n=11), and high flow/high pressure (Pp/Ps> or =50%, HF-HP, n=19). HF-HP and HF-LP received alpha-blockers (chlorpromazine and/or prazosin). HF-HP patients received nitric oxide donors (nitroglycerin/sodium nitroprusside). ET-1 peaked at 6 hours, with its highest level in the HF-HP group (P<.01, by ANOVA). ET-1 correlated significantly with Pp/Ps at 6 hours (r2=.43, P<.005). In the HF-HP group, ET-1 remained above the other groups at 12 hours (12.7+/-2.5 pg/mL versus 6.4+/-1.1 pg/mL versus 6.5+/-3.8 pg/mL P<.05 by ANOVA). NO metabolites were elevated equivalently for the HF-HP and HF-LP groups (5.7+/-2.6 micromol/L versus 0.3.5+/-2.5 micromol/L at 12 hours, P=NS) despite nitric oxide donors and the excess ET-1 in HF-HP patients. Levels of cGMP were similarly elevated in HF-HP and HF-LP patients during this study.

CONCLUSIONS

Endogenous NO may decrease vascular tone and maintain low pulmonary pressure in HF-LP patients. High levels of ET-1, inadequate NO production, and/or impaired responses to NO may increase pulmonary pressure in HF-HP patients.

Aryl sulfotransferase IV deficiency in rat liver carcinogenesis initiated with diethylnitrosamine and promoted with N-2-fluorenylacetamide or its C-9-oxidized metabolites

Down regulation of aryl sulfotransferase IV (AST IV) in promotion/progression of liver carcinogenesis by N-2-fluorenylacetamide (2-FAA) has been established. This study examined whether the C-9 oxidized metabolites of 2-FAA, which have recently been shown to promote diethylnitrosamine (DEN)-initiated liver carcinogenesis in male Sprague-Dawley rats, effect the above change. Hence, in DEN-initiated rats, the effects of promoting regimens of 9-OH-2-FAA or 9-oxo-2-FAA, 15 oral doses at 50 and 100 mumol/kg of body weight, were compared to those of 2-FAA at 50 mumol/kg of body weight and of the vehicle on the activity of N-hydroxy(OH)-2-FAA sulfotransferase (ST), an isozyme of AST IV and AST IV expression and distribution. Relative to the vehicle, treatment with the fluorenyl compounds led to decreased levels in hepatic N-OH-2-FAA ST activity and development of hepatic nodules and tumors which had still lower levels of the ST activity than the respective remnant livers. At approximately 8 months after treatment with the C-9-oxidized compounds at doses twice that of 2-FAA, the extents of decreases in the hepatic N-OH-2-FAA ST activity and cytosolic AST IV protein in tumors were comparable to those with 2-FAA. Immunocytochemical analysis showed close association of AST IV deficiency with neoplastic liver lesions. In comparison to N-OH-2-FAA, 9-OH-2-FAA had only low and 9-oxo-2-FAA lacked sulfate acceptor activity in the presence of male rat liver cytosol or AST IV. At 3.3-fold greater concentration than N-OH-2-FAA, 9-oxo-2-FAA inhibited (27%) the sulfate acceptor activity of N-OH-2-FAA in the presence of AST IV, which suggested interference by 9-oxo-2-FAA at the active site. Although the C-9-oxidized compounds do not appear to be substrates for N-OH-2-FAA ST, their ability to cause a decrease in N-OH-2-FAA ST activity and protein similar to that of 2-FAA supports their role in hepatocarcinogenesis. Whereas 9-OH-2-FAA had a 3.9-fold greater sulfate acceptor activity in the presence of female than male rat liver cytosol and inhibited dehydroepiandrosterone ST activity of female rat liver, N-OH-2-FAA and 9-oxo-2-FAA inhibited estrone ST activity of male rat liver, suggesting that the C-9-oxidized compounds as well as N-OH-2-FAA are substrates for STs other than AST IV.

Promoting activities of the C-9 oxidized metabolites of N-2-fluorenylacetamide in liver carcinogenesis in the rat

The promoting potential of the C-9 oxidized metabolites of N-2-fluorenylacetamide (2-FAA) was examined and compared to that of the promoter 2-FAA in the two-stage hepatocarcinogensis system Male Sprague Dawley rats were initiated with a single intraperitoneal injection of diethylnitrosamine at 200 mg/kg of body weight (b.wt.). One, 2 and 5 weeks thereafter rats were given by gavage 5 doses per week of 2-FAA (0.05 mmol/kg of b.wt.), 9-hydroxy- or 9-oxo-2-FAA (0.05 and 0.1 mmol/kg of b.wt.) or the vehicle polyethylene glycol 400 (2 ml/kg of b.wt.). All rats underwent partial (70%) hepatectomy on day 3 after 5 initial doses. Following treatment with 2FAA, 9-hydroxy-or 9-oxo-2-FAA, the levels of gamma-glutamyl-transpeptidase activity and placental glutathione S-transferase (GST-P) were increased in the livers proportional to the increased numbers of foci of GST-P positive hepatocytes. The activities of the C-9 oxidized compounds were dose-dependent since treatment at 0.1 mmol/kg of b.wt. resulted in -2-fold greater effects than that at 0.05 mmol/kg of b.wt. The incidences of hepatocellular carcinoma increased with time after treatment and the relative order of potency was: 2-FAA>9-oxo-2-FAA>9-hydroxy-2-FAA. These data combined with our earlier evidence for preferential oxidations of 2-FAA at C-9 by hepatic microsomes of male Sprague Dawley rats support the significance of these metabolites as a promoting stimuli in liver carcinogenesis by 2-FAA.

Modulations of hepatic gamma-glutamyltranspeptidase and N-hydroxy-N-2-fluorenylacetamide sulfotransferase activities following treatment of rats with a hepatocarcinogenic regimen: effect of partial hepatectomy

The feasibility of using biochemical assays of gamma-glutamyltranspeptidase (gamma-GTP) and N-hydroxy-N-2-fluorenylacetamide sulfotransferase (N-OH-2-FAA ST) activities to monitor the effects of treatment of male Sprague-Dawley rats with a two-stage hepatocarcinogenic regimen was investigated. One week after initiation with diethylnitrosamine (200 mg/kg of bw), the rats were treated with 10 oral doses within 2 weeks of N-2-fluorenylacetamide (2-FAA) at 0.05 mmole/kg or vehicle (corn oil) at 5 ml/kg of body weight. After five doses of 2-FAA or corn oil, half of the rats in each group underwent partial (70%) hepatectomy (PH). Three days after completion of 2-FAA treatment, gamma-GTP activity increased approximately 8-fold in the livers of both the nonhepatectomized (-PH) and hepatectomized (+PH) groups. After 17 days, the enzyme activity decreased to the control level in the -PH group but increased 3.1-fold above the control level in the +PH group. After 31, 66, and 87 days, gamma-GTP activity increased only 1.4- to 2.6-fold in the -PH group, whereas that of +PH group increased 15- to 32-fold. N-OH-2-FAA ST activity, determined 3 days after completion of 2-FAA treatment, decreased by approximately 60% in the -PH and +PH groups. After 17 days, the effect of PH became evident in that the losses of N-OH-2-FAA ST activity were smaller (20%) in the -PH than in the +PH group (45.5%). After 31, 66, and 87 days, the respective decreases of 27, 29, and 41% in the +PH group were significant.(ABSTRACT TRUNCATED AT 250 WORDS)