Metabolites in Conocarpus erectus leaves attenuate α-amylase activity by modulating amino acid residues of α-amylase: an in vitro and docking study / Los metabolitos en las hojas de Conocarpus erectus atenúan la actividad de la α-amilasa al modular los residuos de aminoácidos de la α-amilasa: un estudio in vitro y de acoplamiento

The antioxidant activity and the inhibitory potential of α-amylase of lyophilized hydroethanolic extracts of Conocarpus erectus leaves obtained by ultrasonication were determined. The most potent extract was subjected to ultra-high performance liquid chromatography system equipped with mass spectrometer for metabolite identification. The identified metabolites were docked in α-glucosidase to assess their binding mode. The results revealed that 60% ethanolic extract exhibited highest ferric reducing antioxidant power (4.08 ± 0.187 mg TE/g DE) and α-amylase inhibition (IC50 58.20 ± 1.25 µg/mL. The metabolites like ellagic acid, 3-O-methyl ellagic acid, ferujol, 5, 2 ́-dihydroxy-6,7,8-trimethyl flavone and kaempferol glucoside were identified in the extract and subjected to molecular docking studies regarding α-amylase inhibition. The comparison of binding affinities revealed 3-O-methyl ellagic acid as most effective inhibitor of α-amylase with binding energy of -14.5911 kcal/mol comparable to that of acarbose (-15.7815 kcal/mol). The secondary metabolites identified in the study may be extended further for functional food development with antidiabetic properties.

Se determinó la actividad antioxidante y el potencial inhibidor de la α-amilasa de extractos hidroetanólicos liofilizados de hojas de Conocarpus erectus obtenidos por ultrasónicación. El extracto más potente se sometió a un sistema de cromatografía líquida de ultra alto rendimiento equipado con un espectrómetro de masas para la identificación de metabolitos. Los metabolitos identificados se acoplaron en α-glucosidasa para evaluar su modo de unión. Los resultados revelaron que el extracto etanólico al 60% exhibió el mayor poder antioxidante reductor férrico (4.08 ± 0.187 mg TE/g DE) e inhibición de la α-amilasa (IC50 58.20 ± 1.25 µg/mL. Los metabolitos como el ácido elágico, 3-O-metil elágico ácido, ferujol, 5, 2 ́-dihidroxi-6,7,8-trimetil flavona y kaempferol glucósido se identificaron en el extracto y se sometieron a estudios de acoplamiento molecular con respecto a la inhibición de la α-amilasa. La comparación de las afinidades de unión reveló 3-O-metil El ácido elágico como inhibidor más eficaz de la α-amilasa con una energía de unión de -14,5911 kcal/mol comparable a la de la acarbosa (-15,7815 kcal/mol). Los metabolitos secundarios identificados en el estudio pueden ampliarse aún más para el desarrollo funcional de alimentos con propiedades antidiabéticas.

Metabolite profiling and antidiabetic attributes of ultrasonicated leaf extracts of Conocarpus lancifolius

Objective: To profile the secondary metabolites and to evaluate the antidiabetic potential of hydroethanolic leaf extracts of Conocarpus lancifolius.Methods: The various hydroethanolic extracts o f Conocarpus lancifolius leaf were prepared by ultrasonication assisted freeze-drying. Total phenolic contents, flavonoid contents, antioxidant activity, α-glucosidase and α-amylase inhibitions of leaf extracts were determined. The metabolite profiling was accomplished by UHPLC-Q-TOF-MS/MS analysis. The antidiabetic assessment of the most potent extract was carried out by measuring the hypoglycemic and hypolipidemic effect in the high fat diet-fed diabetic albino mice. The blood glucose level, haemoglobin, total cholesterol, high-density lipoproteins (HDL) and low-density lipoproteins (LDL) were determined. Results: The 60％ ethanolic extract exhibited the highest phenolic and flavonoid contents of (349.39 ± 2.13) mg GAE/g dry extract and (116.95 ± 2.34) mg RE/g dry extracts, respectively, and the highest DPPH scavenging activity with an IC50 value of (32.87 ± 1.11) μg/mL. The IC50 values for α-glucosidase and α-amylase inhibitions were (38.64 ± 0.93) μg/mL and (44.80 ± 1.57) μg/mL, respectively. UHPLC-Q-TOF-MS/MS analysis confirmed the presence of gallic acid, ellagic acid, corilagin, kaempherol-3-O-rutinoside, caffeic acid derivative, isorhamnetin and galloyl derivatives in the 60％ ethanolic extract. Plant extract at a dose of 450 mg/kg body weight reduced blood glucose level, total cholesterol, LDL and HDL, and increased haemoglobin in alloxan-induced diabetic mice, Conclusions: Conocarpus lancifolius leaves are proved as a good source of biologically functional metabolites and possess antidiabetic activity which may be further explored to treat diabetes.

Bromelain: Methods of Extraction, Purification and Therapeutic Applications

Bromelain is a concoction of sulfhydryl proteolytic enzymes. Depending upon the site of extraction it can be regarded as either stem bromelain (SBM) (EC 3.4.22.32) or fruit bromelain (FBM) (EC 3.4.22.33). Bromelain remain enzymatic active over a broad spectrumand endure a range of pH (5.5 to 8.0) and temperature (35.5 to 71 ºC). It is one of the extensively investigated proteolytic enzyme owing to its astonishing applications in various industries. This necessitated employing a strategy that result in highest purified bromelain in less steps and lowest cost. Use of modernistic approach such as membrane filtration, reverse micellar systems, aqueous two phase extraction and chromatographic techniques have shown promise in this regard. Besides its industrial applications, bromelain has been widely utilized as a potential phytomedical compound. Some of its reported actions include inhibition of platelet aggregation, anti-edematous, anti-thrombotic, anti-inflammatory, modulation of cytokines and immunity, skin debridement and fibrinolytic activity. It also assist digestion, enhance absorption of other drugs and is a potential postoperatively agent that promote wound healing and reduce postsurgical discomfort and swelling.

Isolation and Identification of Glucose Oxidase Hyper Producing Strain of Aspergillus niger.

Aims: Glucose oxidase is an enzyme with large scale applications in various industries. It is also used in several diagnostic kits which makes it medically important as well. Our aim was to isolate indigenous glucose oxidase hyper producing strain of Aspergillus niger from different soil samples of Punjab, Pakistan. Study Design: An experimental study. Place and Duration of Study: Institute of Industrial Biotechnology, GC University, Lahore from March 2011 to July 2012. Methodology: Two hundred and seventy nine fungal strains were isolated from soil of different localities of Punjab. Isolates were screened for glucose oxidase production using submerged fermentation. Glucose oxidase hyper producer isolate was identified using morphological and molecular techniques i.e. 18S rDNA. DNA was isolated and amplified using PCR. Gene sequencing was done and homology analysis was studied. Rate of glucose oxidase production was also analysed. Results: Glucose oxidase hyper producing isolate was identified as A. niger A247 strain. This strain gave best reproducible results (145.22 ±0.034 U/g of cell mass) after 72 hrs of fermentation at 30ºC and at a medium pH of 7.2. Conclusion: Our results indicate the natural ability of A. niger to produce Glucose oxidase in large quantity instead of using genetic manipulation techniques.

Concomitant production of two proteases and alpha-amylase by a novel strain of Bacillus subtilis in a microprocessor controlled bioreactor

We describe the simultaneous production of Bacillus subtilis based proteases and alpha amylase using a computer controlled laboratory scale 7.5 L batch bioreactor. The present strain is the first to be reported that concomitantly produces these two industrially important enzymes. The growth and sporulation of Bacillus subtilis was monitored and maximum production of alkaline protease and alpha amylase was found to coincide with maximum sporulation. Two types of proteases were detected in the fermentation broth; a neutral and an alkaline protease most active in a pH range of 7.0-8.0 and 8.0-10, respectively. Maximum production of proteases was observed at an incubation temperature of 37ºC while that of alpha amylase was observed at 40ºC. The optimum aeration and agitation levels for protease production were 0.6 L/L/min and 200rpm, respectively, and for alpha amylase were 0.6 L/L/min and 150 rpm. The kinetic parameters Yp/x and qp were also found to be significant at the given fermentation conditions.

Biosynthesis of protease from Lactobacillus paracasei: kinetic analysis of fermentation parameters.

Fifteen strains of Lactobacillus species, isolated from different samples of curd were screened for their ability to produce more extracellular protease. The proteolytic activities of these strains based on casein hydrolysis showed a variation of 1.26-5.80 U ml(-l), with Lactobacillus IH8 showing the maximum activity and was identified as L. paracasei. Different cultural conditions for enhanced production of protease by L. paracasei were optimized. The optimal conditions for production of the enzyme were an incubation temperature of 35 degrees C and a medium pH of 6.0. The maximum proteolytic activity of L. paracasei (7.28 Uml(-1)) was achieved after 48 h of cultivation. The kinetic parameters such as product yield (Yp/x,), growth yield (Yx/s), specific product yield (qp) and specific growth yield (qs) coefficients also revealed that the values of experimental results were kinetically significant.