Antimicrobial Activity of Crude Metabolites of Vitis vinifera using Methanol Extract against the Clinical Pathogens.

Background: The Vitis vinifera, also known as grapevine, is one of the most widely grown fruit crops in the world and is renowned for producing wine and grapes. Other than their importance in gastronomy and ecology, certain sections of the V. vinifera plant have shown promising bioactive qualities. The numerous phytochemicals in this plant, including flavonoids, stilbenes, and phenolic acids, are what gives its antibacterial and antifungal properties though the antimicrobial properties of seed extract have to be studied, however in this present study we focus on screening and its biological compatibility of seed extracts of V. vinifera. Methods: The commercial power of seed (V. vinifera) obtained from local market near Poonamallee, Chennai, India. and the extraction of crude metabolites was done by direction extraction method, the antimicrobial activity was done by well diffusion method, and Minimum Inhibitory concentration was done by CLSI guideline. To check the biocompatibility of crude metabolites was done by hemolytic assay. Results: Studies have demonstrated that grapevine extracts and their separated components have potent antibacterial and antifungal effects against a variety of pathogenic microorganisms, including bacterial strains that are resistant to antibiotics. The Minimum Inhibitory Concentration of the plant's extracts have demonstrated potential 128 µg/mL for S. aureus, and 256 µg/mL E. faecalis and C. albicans as the best inhibitory concentration. The biological compatibility of crude metabolites shows 3 % of lysis at 512 µg/mL. Conclusion: V. vinifera is a prospective source for the creation of novel antimicrobial drugs because of its antibacterial capabilities. To completely understand the chemicals' mode of action and to create efficient treatments for microbial illnesses, more research is necessary.

Antimicrobial Activity and Biological Compatibility Study of Methanolic Crude Extract of Senna auriculata (Flower).

Senna auriculata is a little flowering tree or shrub that is indigenous to India and Sri Lanka. It is also known by the names Tanner's Cassia and Avarampoo. It is a member of the Fabaceae family and is popular for its therapeutic and beautifying effects. S. auriculata is used in traditional medicine to treat a wide range of conditions, including diabetes, fever, inflammation, skin problems, and liver issues. However, the antimicrobial activity of different species of S. auriculata from Tamil Nadu is still not fully explored. In this present study, the antimicrobial activity of S. auriculata (Flower) was obtained and shade dried and extracted the crude metabolites the, extracted metabolites was screened for it's antimicrobial properties and biological compatibility. The antimicrobial activity of crude metabolites shows 14 mm zone of inhibition (ZOI) for S. aureus at 2 mg/well, whereas the P. aeruginosa and C. albicans show 12 mm ZOI for at 2 mg/well concentration. The minimum inhibitory concentration also shows the 128 µg/mL for S. aureus and 256 µg/mL P. aeruginosa and E. faecalis. The biological compatibility of crude metabolites shows 5% of hemolytic activity at higher concentrations the compound the metabolites having S. auriculata (Flower) may be biologically compatible.

Antibacterial Activity of Hibiscus sabdariffa (Rosella) Using Methanolic Extract.

Hibiscus sabdariffa L. (Rosella) has a long history of use in food preparation, herbal remedies, hot and cold beverages, food industry flavoring, and herbal drinks. More than 300 species of Hibiscus are grown all over the world. It is an annual herbaceous shrub belonging to the family Malvacea. However, limited is known about the antimicrobial properties of H. sabdariffa; the purpose of this study was to investigate the antimicrobial activity of H. sabdariffa (Rosella) extract against a range of pathogens, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The results of the study showed that H. sabdariffa (Rosella) extract had a significant antimicrobial effect, against S. aureus and E. coli. Further the minimum inhibitory concentration (MIC) shows 128 µg/mL concentration followed by E. coli 256 µg/mL. The biocompatibility of crude metabolites shows highly compatible with Red blood cells (RBC's). This finding suggests that the crude metabolites of H. sabdariffa (Rosella) could be the source to control the human pathogens.

An Indian butyrylcholinesterase variant L307P is not structurally stable: a molecular dynamics simulation study.

The human butyrylcholinesterase (BChE) activity is less than 1% in the serum of silent variant individuals of Vysya community in India. They are homozygous for a point mutation at codon 307 (CTT → CCT) resulting in the substitution of leucine 307 by proline. The reason for the disappearance of the protein in the serum has not been explicated till date. Based on this background, we performed molecular dynamics simulation to probe the structural stability of Indian variant (L307P) in comparison with wild and other BChE variants (D70G, E497V, V142M) having differential esterase activity. The simulation of all the mutants except D70G showed a much larger Cα root mean square deviation from the wild BChE crystal structure, showing the overall conformational disturbance. Further analysis revealed that secondary structure of the mutant proteins was not stable. The orientation of the catalytic triad is also distorted in all the mutants. The distance between δ nitrogen of His438 to ε oxygen of Glu325 and ε nitrogen of His438 to γ oxygen of Ser198 were highly altered in L307P mutant than the wild and other three variants throughout the simulation. Such disparity of distances between the catalytic residues may be due to the change in the protein conformation attributing to their differential catalytic activity. Our studies thus prove that the Indian BChE L307P mutant with negligible activity is possibly due to its structural instability when compared to other BChE variants.

Footprinting of inhibitor interactions of in silico identified inhibitors of trypanothione reductase of Leishmania parasite.

Structure-based virtual screening of NCI Diversity set II compounds was performed to indentify novel inhibitor scaffolds of trypanothione reductase (TR) from Leishmania infantum. The top 50 ranked hits were clustered using the AuPoSOM tool. Majority of the top-ranked compounds were Tricyclic. Clustering of hits yielded four major clusters each comprising varying number of subclusters differing in their mode of binding and orientation in the active site. Moreover, for the first time, we report selected alkaloids and dibenzothiazepines as inhibitors of Leishmania infantum TR. The mode of binding observed among the clusters also potentiates the probable in vitro inhibition kinetics and aids in defining key interaction which might contribute to the inhibition of enzymatic reduction of T[S] 2. The method provides scope for automation and integration into the virtual screening process employing docking softwares, for clustering the small molecule inhibitors based upon protein-ligand interactions.

Screening natural products database for identification of potential antileishmanial chemotherapeutic agents.

Leishmaniasis is a parasitic infection caused by unicellular protozoan organism belonging to the family Trypanosomatidae. Among various forms of the disease, visceral leishmaniasis is the most lethal and caused by Leishmania infantum or Leishmania donovani. The redox metabolism of parasite requires a key enzyme, trypanothione reductase which is a validated drug target. In the past decade, it was observed that these protozoan parasites had developed resistance against many of available drugs. Importantly in the case of visceral leishmaniasis drug resistance is very high in the Indian subcontinent, a major endemic region of Leishmania donovani infection. In search for new drugs, we aim to identify potential natural product inhibitors of trypanothione reductase which can be further developed as anti-leishmanial drug. We have performed in silico virtual screening of a natural product data set of 800 diverse chemical entities. Leishmania infantum trypanothione reductase crystal structure (PDB ID: 2JK6) was used in the virtual screening process, docking studies to identify potential lead compounds. The compounds were sorted based upon their binding energy and the top 50 ranked protein-inhibitor complexes were clustered using AuPosSOM to ligand foot print the interactions. We report a few alkaloids and sterols for the first time, which could be potential trypanothione reductase inhibitors. The footprinting of protein-inhibitor interactions into clusters has also provided clues on various possible orientations that inhibitors can attain at the active site of Trypanothione reductase. Moreover, biological significance of the interactions has also been discussed.

Mitogen-activated protein kinase 4 of Leishmania parasite as a therapeutic target.

Protein kinases are important regulators of many different cellular processes such as transcriptional control, cell cycle progression and differentiation, and have drawn much attention as potential drug targets. Leishmania mexicana mitogen-activated protein kinase 4 (LmxMPK4) is crucial for the survival of the parasite. As the crystal structure of the enzyme is not known, we have used bioinformatics techniques to model LmxMPK4 structure. The current study reveals conservation of all sequence and structural motifs of LmxMPK4. Study shows mitogen-activated protein kinases are highly conserved throughout different Leishmania species and significant divergence is observed towards mammalian mitogen-activated protein kinases. Additionally, using virtual docking methods, we have identified inhibitors for LmxMPK4. The sequence and structure analysis results were helpful in identifying the ligand binding sites and molecular function of the Leishmania specific mitogen-activated protein kinase.

Molecular docking studies of selected tricyclic and quinone derivatives on trypanothione reductase of Leishmania infantum.

Visceral leishmaniasis, most lethal form of Leishmaniasis, is caused by Leishmania infantum in the Old world. Current therapeutics for the disease is associated with a risk of high toxicity and development of drug resistant strains. Thiol-redox metabolism involving trypanothione and trypanothione reductase, key for survival of Leishmania, is a validated target for rational drug design. Recently published structure of trypanothione reductase (TryR) from L. infantum, in oxidized and reduced form along with Sb(III), provides vital clues on active site of the enzyme. In continuation with our attempts to identify potent inhibitors of TryR, we have modeled binding modes of selected tricyclic compounds and quinone derivatives, using AutoDock4. Here, we report a unique binding mode for quinone derivatives and 9-aminoacridine derivatives, at the FAD binding domain. A conserved hydrogen bonding pattern was observed in all these compounds with residues Thr335, Lys60, His461. With the fact that these residues aid in the orientation of FAD towards the active site forming the core of the FAD binding domain, designing selective and potent compounds that could replace FAD in vivo during the synthesis of Trypanothione reductase can be deployed as an effective strategy in designing new drugs towards Leishmaniasis. We also report the binding of Phenothiazine and 9-aminoacridine derivatives at the Z site of the protein. The biological significance and possible mode of inhibition by quinone derivatives, which binds to FAD binding domain, along with other compounds are discussed.