Abdulhameed Sabu

Cuminaldehyde as a Lipoxygenase Inhibitor: In Vitro and In Silico Validation

The search for lipoxygenase (LOX) inhibitors has been carried out for decades due to its importance in inflammatory diseases. In the present study, it was observed that the methanolic extract of Cuminum cyminum L. inhibited LOX activity. Activity-guided screening of the C. cyminum crude extracts helped the identification and isolation of cuminaldehyde as a 15-LOX inhibitor. The enzyme kinetics analysis suggested cuminaldehyde to be a competitive inhibitor and the IC50 value derived from LB plots is 1,370xa0μM. Binding constants of cuminaldehyde on LOX was deduced by isothermal titration calorimetry. The combined thermodynamics and molecular modeling analyses suggested cuminaldehyde as a competitive LOX inhibitor. It is proposed from the present study that the coordinate bond between the Fe2+ atom in the active site of the enzyme and the cuminaldehyde may be responsible for the enzyme inhibition. The study suggests that cuminaldehyde may be acting as an anti-inflammatory compound and may be therefore included in the category of leads for developing dual COX-LOX inhibitors as non-steroidal anti-inflammatory drugs (NSAIDs).

Inverted binding due to a minor structural change in berberine enhances its phospholipase A2 inhibitory effect

Biotransformation of berberine by Rhizopus oryzae leads to its demethylation, producing hydroxyl derivatives, as revealed by Fourier Transform Infra Red spectroscopy, Nuclear Magnetic Resonance and Electro Spray Ionization-Mass Spectrometric analyses. Surface Plasmon Resonance and enzyme kinetic studies showed that biotransformed derivatives of berberine had a higher inhibitory potential than berberine towards phospholipase A(2). X-ray crystal structures demonstrated that biotransformed berberine binds to PLA(2) in an entirely different, inverted orientation with respect to the binding of berberine. This study brings out the significance of biotransformation in generation of better drug-lead compounds.

Traditional fermentation of Ayurvedic medicine yields higher proinflammatory enzyme inhibition compared to wine-model product

This study investigated the process of preparing fermented medicines as prescribed in Ayurveda, the traditional Indian system of medicine. Berberine, an alkaloid, was used as a model compound. Berberine is the active constituent of Berberis aristata and is alleged to have anti-inflammatory effect. Biotransformation of berberine was studied by the phospholipase A2 assay in fermented products prepared in traditional and commercially available brewers yeast-induced environments. Sugar and alcohol levels were estimated to indicate the culmination of fermentation. It was confirmed that traditional fermentation biotransforms berberine to a greater extent than commercially available brewers yeast-induced fermentation. Therefore, fermentation induced by commercially available yeast is no substitute for the ethnopharmacological and traditional fermentation prescribed in the traditional Indian system of medicine.

Therapeutic Enzymes: l-Glutaminase

Abstract Glutamine aminohydrolase (glutaminase or l -glutaminase; EC 3.5.1.2) is an amidase enzyme that converts glutamine to glutamate with the release of ammonia. It acts as an endopeptidase, hydrolyzing the peptide bonds present in the interior of a protein molecule [1] . The enzyme was named after the discovery of its activity by Hans Krebs in 1935. It mainly catalyzes the hydrolysis of the γ-amido bond of l -glutamine and it plays a major role in the nitrogen metabolism of both prokaryotes and eukaryotes [2] . Glutaminase is seen in the inner membrane of mitochondria and is the predominant glutamine-using enzyme in the brain. Microorganisms are also well known producers of this commercially important enzyme. l -Glutaminase is widely used as an oncolytic enzyme and as an antiretroviral agent because of its capability to degrade small molecules like glutamine. Glutaminase also finds application in the food industry as a flavor-enhancing agent. The sources, production strategies, characteristics, and applications of l -glutaminase are discussed here.

Dioxygenase from Aspergillus fumigatus MC8: molecular modelling and in silico studies on enzyme-substrate interactions

Flavoenzymes have been extensively studied for their structural and mechanistic properties because they find potential application as industrial biocatalysts. They are attractive for biocatalysis because of the selectivity, controllability and efficiency of their reactions. Some of these enzymes catalyse the oxidative modification of protein substrates. Among them oxygenases (monoxoygenases and dioxygenases) are of special interest because they are highly entantio as well as regio-selective and can be used for oxyfunctionalisation. Dioxygenase enzymes catalyse oxygenation reactions in which both di-oxygen atoms are incorporated into the product. A dioxygenase enzyme purified from Aspergillus fumigatus MC8 was subjected to protein digestion followed by peptide sequencing. The sequence analysis of the peptide fragments resulted in identifying its match with that of an extracellular dioxygenase sequence from the same species of fungus existing in the protein database. The sequence was submitted to protein homology/analogy recognition engine online server for homology modelling and the 3D structure was predicted. Subsequently, the in silico studies of the enzyme–substrate (protein–ligand) interaction were carried out by using the method of molecular docking simulations wherein the modelled dioxygenase enzyme (protein) was docked with the substrates (ligands), catechin and epicatechin.

Novel lipoxygenase inhibitor, 1-ethenoxy-2-methylbenzene, from marine cyanobacteria Microcoleus chthonoplastes

Abstract Lipoxygenase (LOX) inhibitors are considered to be important anti-inflammatory agents as it can control many inflammatory responses to some extent. Even though the marine bio-systems are not well explored, they are considered to be one of the promising repositories for drug lead molecules against variety of diseases. In the present study a new LOX inhibitor compound, 1-ethenoxy-2-methylbenzene, reported first time from a living system, Microcoleus chthonoplastes, has been isolated by activity guided fractionation and further structurally characterised by techniques such as FTIR, NMR and LC MS/MS. Further enzyme kinetics, isothermal titration calorimetry and molecular docking methods were used in order to get a better understanding of enzyme–ligand interactions. This exploration suggests its worthiness as a lead molecule for the development of a better anti-inflammatory drug. Its high structure–activity resemblance to cuminaldehyde from cumin seeds, which is earlier reported as a LOX inhibitor, is also established.

A Novel, Poly(Ethyl Ethylene Ether) Inhibitor to Trypsin from Marine Cyanobacteria, Lyngbya confervoides

A novel, poly(ethyl ethylene ether) inhibitor to trypsin was purified from marine cyanobacteria, Lyngbya confervoides from the coastal areas of Thalassery, North Kerala. The kinetics and the thermodynamic parameters of its interactions with the enzyme were also studied. It was demonstrated that the substrate binding, catalytic triad of the enzyme could be blocked by the inhibitor, as expressed by molecular simulation studies. The study also showed that the cyanobacterial group could prove to be a potential source of novel enzyme inhibitors for various applications.

Fermentation in ancient Ayurveda: Its present implications

A review of fermentation practised in Ayurveda, together with the literature produced on various aspects of Ayurvedic fermentation, is presented. The analyses may be viewed in the following categories: classical prescriptions for fermentative production of Ayurvedic drugs, physicochemical parameters of fermented Ayurvedic drugs, changes observed in medicinal tinctures due to fermentation, significance of changes due to fermentation, clinical evaluation of fermented drug products of Ayurveda, prospects for research on fermented Ayurvedic drugs and solid-state fermentation in Ayurveda. The strength of fermentation as a unique method of preparing herbal drugs as described in classical texts of Ayurveda, as well as deficiencies in the analyses of the Ayurvedic fermentative process as evidenced in research publications, is also assessed. The review of the process also highlights the significance of solid-state fermentation, employed in the preparation of certain Ayurvedic pills as a tradition in Kerala, India, as an improvement on the classical text, Ashtangahrudayam. Emphasis is also given to the need for critical studies to understand the differences between tinctures and fermented liquors and their therapeutic applications, to improve and find new applications of the fermented Ayurvedic drugs. Rational drug design-protocol based modification and synthesis of analogues, supported and guided by the biotransformation evidenced in fermented polyherbal formulae, as prescribed effectively in Ayurvedic classics, would be a novel working principle for achieving better therapeutics for other systems of medicine as well.

New Features and Properties of Microbial Cellulases Required for Bioconversion of Agro-industrial Wastes

Abstract A relevant and modern objective for second-millennium biotechnology is the enzymatic conversion of renewable cellulosic biomass to inexpensive fermentable sugars. New and more efficient fermentation processes will convert this biological “currency” to a variety of commodity products. Although early strides will be made using process development and engineering disciplines, mid-term and longer advances must rely heavily on insight gained through protein and metabolic engineering technologies. These challenging goals can be met most effectively by the full integration of academic, federal, and industrial efforts in teams that develop and apply new fundamental knowledge to key cost drivers. The present chapter describes a comprehensive and illustrative analysis on basic and applied aspects of fungal cellulases. A description of different substrates of cellulases as well as fundamental biotechnological and catalytic aspects are reviewed and discussed to illustrate the potential of cellulases in the food and bioprocess industries. Moreover, an emphasis on the scientific and technological advances and challenges of cellulase study is also described.

Coffee Husk: A Potential Agro-Industrial Residue for Bioprocess

Agro-industrial processing always generates waste materials. Coffee is one of the largest commodities in the world, and its processing yields coffee husk as waste by-product. Its disposal without proper treatment can cause serious environmental problems. Coffee husk contains carbohydrates including fermentable sugars, polyphenols such as tannins, lipids. Various microorganisms including filamentous fungi are reported to grow on it despite the presence of antimicrobial compounds. Chemical nature of coffee husk makes it a suitable and inexpensive source for solid-state fermentation. Several studies have been reported on the application of coffee husk in bioprocess. It acts as a substrate as well as carbon source during fermentation. Production of various enzymes such as xylanases, cellulases, polygalacturonases, polyphenol oxidases, tannases in high titers can be achieved by fermentation using coffee husk as substrate. Apart from production of enzymes, bioconversion of coffee husk is also achieved during bioprocess which in turn favors sustainable utilization of waste products. Production of citric acid, gibberellic acid, gallic acid, polyhydroxyalkanoates (PHA), and bacterial cellulose is reported by fermentation using coffee husk as substrate. Mass production of microorganisms is another advantage of using coffee husk in bioprocess. It is excellent for the growth of various biocontrol agents such as Trichoderma sp. Besides economic production, prolonged shelf life of biocontrol agents multiplied on coffee husk makes it more attractive. Biopesticides such as Bacillus sphaericus and B. thuringiensis can also be produced by solid-state fermentation on coffee husk. The sustainable management of agro-industrial waste like coffee husk through bioprocess makes it as an attractive source of wealth.