Plant-based Natural Products as inhibitors for Efflux Pumps to Reverse Multidrug Resistance in Staphylococcus aureus: A Mini Review.

Wounds provide a favourable site for microbial infection. Wound infection makes the healing more complex and does not proceed in an orchestrated manner leading to the chronic wound. Clinically infected wounds require proper antimicrobial therapy. Broad-spectrum antibiotics are usually prescribed first before going to targeted therapy. The current conventional mode of therapy mainly depends on the use of antibiotics topically or systemically. Repeated and prolonged use of antibiotics, however, leads to multidrug resistance. Staphylococcus aureus is the most common multidrugresistant microorganism found in wounds. It effectively colonizes the wound and produces many toxins, thereby reducing the host immune response and causing recurrent infection, thus making the wound more complex. The overexpression of efflux pumps is one of the major reasons for the emergence of multidrug resistance. Inhibition of efflux pumps is, therefore, a potential strategy to reverse this resistance. The effective therapy to overcome this antibiotic resistance is to use combination therapy, namely the combination of an inhibitor, and a non-antibiotic compound with an antibiotic for their dual function. Many synthetic efflux pump inhibitors to treat wound infections are still under clinical trials. In this connection, several investigations have been carried out on plant-based natural products as multidrug resistance-modifying agents as they are believed to be safe, inexpensive and suitable for chronic wound infections.

1-Tetracosanol isolated from the leaves of Eupatorium glandulosum, accelerates wound healing by expressing inflammatory cytokines and matrix metalloproteinase.

ETHNOPHARMACOLOGICAL RELEVANCE: The leave paste of the plant, Eupatorium glandulosum H. B & K, has been traditionally used to treat cuts and wounds by the tribal community of the Nilgiris district of Tamilnadu, India. AIM OF THE STUDY: The present study was carried out to investigate the wound healing potential of this plant extract and the compound, 1-Tetracosanol, isolated from the ethyl acetate fraction. MATERIALS AND METHODS: An in vitro study was designed to compare the viability, migration and apoptosis of the fresh methanolic extract fractions and 1-Tetracosanol using mouse fibroblast NIH3T3 cell lines and human keratinocytes HaCaT cell lines, respectively. 1-Tetracosanol was evaluated for its viability, migration, qPCR analysis, in silico, in vitro and in vivo. RESULTS: 1-Tetracosanol at the concentration of 800, 1600, 3200 µM has significant wound closure of 99% at 24 h. The compound when screened in silico against various wound healing markers, TNF-α, IL-12, IL-18, GM-CSF and MMP-9, revealed high binding energy of -5, 4.9 and -6.4 kcal/mol for TNF-α, IL-18 and MMP-9, respectively. Gene expression and the release of cytokines increased at an early stage of the wound repair. 1-Tetracosanol, at 2% gel showed 97.35 ± 2.06% wound closure at 21st day. CONCLUSION: 1-Tetracosanol is a good lead for drug development targeted towards wound healing activity and work in this direction is in progress.

Plant-based Natural Products for Wound Healing: A Critical Review.

Wound healing is an intricate process consisting of four overlapping phases, namely hemostasis, inflammation, proliferation, and remodelling. Effective treatment of wounds depends upon the interaction of appropriate cell types, cell surface receptors, and the extracellular matrix with the therapeutic agents. Several approaches currently used for treating wounds, such as advanced wound dressing, growth factor therapy, stem cell therapy, and gene therapy, are not very effective and lead to impaired healing. Further, repeated use of antibiotics to treat open wounds leads to multi- drug resistance. Today there is considerable interest in plant-based drugs as they are believed to be safe, inexpensive, and more suitable for chronic wounds. For example, a large number of plant- based extracts and their bioactive compounds have been investigated for wound healing. In recent years the structural and mechanistic diversity of natural products have become central players in the search for newer therapeutic agents. In the present review, a thorough critical survey of the traditionally used plant-based drugs used worldwide for wound healing with special reference to the natural products/bioactive compounds isolated and screened is presented. It is hoped that this review will attract the attention of the research community involved in newer drug design and development for wound healing.

Potential inhibitors for FKBP51: an in silico study using virtual screening, molecular docking and molecular dynamics simulation.

Over the years, FK506-binding proteins have been targeted for different pharmaceutical interests. The FK506-binding protein, encoded by the FKBP5 gene, is responsible for stress and metabolic-related disorders, including cancer. In addition, the FKBD-I domain of the protein is a potential target for endocrine-related physiological diseases. In the present study, a set of natural compounds from the ZINC database was screened against FKBP51 protein using in silico strategy, namely pharmacophore modeling, molecular docking, and molecular dynamic simulation. A protein-ligand-based pharmacophore model workflow was employed to identify small molecules. The resultant compounds were then assessed for their toxicity using ADMET prediction. Based on ADMET prediction, 4768 compounds were selected for molecular docking to elucidate their binding mode. Based on the binding energy, 857 compounds were selected, and their Similarity Tanimoto coefficient was calculated, followed by clustering according to Jarvis-Patrick clustering methods (Jarp). The clustered singletons resulted in 14 hit compounds. The top 05 hit compounds and 05 known compounds were then subjected to 100 ns MD simulation to check the stability of complexes. The study revealed that the selected complexes are stable throughout the 100 ns simulation; for FKBD-I (4TW6), crystal structure compared with FKBP-51 (1KT0) crystal structure. Finally, the binding free energies of the hit complexes were calculated using molecular mechanics energies combined with Poisson-Boltzmann. The data reveal that all the complexes show negative BFEs, indicating a good affinity of the hit compounds to the protein. The top five compounds are, therefore, potential inhibitors for FKBP51. Communicated by Ramaswamy H. Sarma.

Virtual high throughput screening: Potential inhibitors for SARS-CoV-2 PLPRO and 3CLPRO proteases.

The pandemic, COVID-19, has spread worldwide and affected millions of people. There is an urgent need, therefore, to find a proper treatment for the novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the causative agent. This paper focuses on identifying inhibitors that target SARS-CoV-2 proteases, PLPRO and 3CLPRO, which control the duplication and manages the life cycle of SARS-CoV-2. We have carried out detailed in silico Virtual high-throughput screening using Food and Drug Administration (FDA) approved drugs from the Zinc database, COVID-19 clinical trial compounds from Pubchem database, Natural compounds from Natural Product Activity and Species Source (NPASS) database and Maybridge database against PLPRO and 3CLPRO proteases. After thoroughly analyzing the screening results, we found five compounds, Bemcentinib, Pacritinib, Ergotamine, MFCD00832476, and MFCD02180753 inhibit PLPRO and six compounds, Bemcentinib, Clofazimine, Abivertinib, Dasabuvir, MFCD00832476, Leuconicine F inhibit the 3CLPRO. These compounds are stable within the protease proteins' active sites at 20ns MD simulation. The stability is revealed by hydrogen bond formations, hydrophobic interactions, and salt bridge interactions. Our study results also reveal that the selected five compounds against PLPRO and the six compounds against 3CLPRO bind to their active sites with good binding free energy. These compounds that inhibit the activity of PLPRO and 3CLPRO may, therefore, be used for treating COVID-19 infection.

A combination of resveratrol and 3,3'-diindolylmethane, a potent radioprotector.

PURPOSE: Exposure to ionizing radiation causes damage to the genomic integrity and stability of the cell. Though a large number of molecules have been studied for their radioprotective capability, no single agent is available today that meets all the requirements of a good radiprotector. In this study, we have investigated a combination of Resveratrol (RSV) and 3,3'-Diindolyl methane (DIM) for its efficacy for radioprotection. It is our hypothesis that this combination that possesses less toxicity than synthetic compounds, free radical scavenging potential, and the capacity to interfere with the several of the signaling cascades that trigger damage to cell by ionizing radiation may possess good radioprotective capability. MATERIALS AND METHODS: Mice were pre-treated with a combination of RSV and DIM and the 30-day mortality assay, endogenous antioxidant levels in intestinal mucosa, metaphase chromosomal aberrations, and micronuclei formation were assessed after exposed to ionizing radiation. RESULTS: The dose modifying factor (DRF) obtained for RSV, DIM, and the combination is 1.15, 1.17, and 1.3, respectively. Pre-treatment of mice with the combination results in significant (***p = .001) protection of the endogenous antioxidant levels, chromosomal aberrations, micronuclei formation, after exposure to ionizing radiation. CONCLUSIONS: Our findings suggest that pre-treatment with the combination of RSV and DIM protects effectively from the ionizing radiation-induced damage at the molecular, cellular, and tissue levels by counteracting both the direct and indirect effects.

Classical taxonomy studies of medicinally important Ipomoea leari.

BACKGROUND: Ipomoea leari which belongs to the family Convolvulaceae is an unexplored medicinal plant in the Indian medicinal system. According to ethnobotanical information, the whole plant is used for various disorders such as anti-inflammatory, psychotomimetic and anticancer activities. The current study seeks to standardize the parameters for this herb. MATERIALS AND METHODS: The identification of the pharmacognostical, morphoanatomical characters of Ipomoea leari (leaf, stem and root) were carried out in terms of organoleptic, macroscopic, microscopic, physicochemical, florescence and phytochemical analyses. Physicochemical parameters such as total ash, moisture content and extractive values were determined by World Health Organization (WHO) guidelines. The plant material was fixed in formalin-5 mL + acetic acid-5 mL + 70% ethyl alcohol-9 mL (FAA) and dehydrated with graded series of tertiary-butyl alcohol. Toluidine blue, a polychromatic stain was used for staining the sections and then whole components were observed with Nikon lab photo device with microscopic units. RESULTS: Microscopically, leaf consists of prominent midrib and the lamina, both having dorsiventral symmetry. The stomata are actinocytic. The stem consists of an epidermal layer of one cell thickness, wide cortex, vascular cylinder and wide pith. The root measuring 1.6 mm thick was studied. It consists of uniformly thick and continuous periderm, wide cortex and thick vascular cylinder. Qualitative analysis revealed the presence of carbohydrates, flavonoids, glycosides, steroids and phenols. The pharmacognostic studies were carried out in terms of macroscopic, phytoconstituent and chromatographic analyses of Ipomoea leari. Various standard methods were adopted to carry out the investigation. CONCLUSION: The results of the present study provide valuable pharmacognostic information of Ipomoea leari for its identification. Our result's suggest that Ipomoea leari is a promising candidate as an adjuvant therapy in various disorders and preparation of monograph.

Elastin-like polypeptides and their applications in anticancer drug delivery systems: a review.

Elastin-like polypeptides (ELPs) are large molecular weight biopolymers. They have been widely studied as macromolecular carriers for targeted delivery of drugs. The aim of the present article is to review the available information on ELPs (including our recent investigations), their properties, drug delivery applications to tumor sites and future perspectives. This review also provides information on the use of short synthetic ELPs for making ELP-drug conjugates, for targeted delivery of anticancer drugs. In the present review we also focus on the point that short ELPs can also be used for targeting anticancer drugs to tumor sites as they behave similar to long ELPs regarding their capacity to undergo inverse temperature transition (ITT) behavior.

Resveratrol for the Management of Diabetes and its Downstream Pathologies.

Over the past 10 years more than 10,000 papers and in vitro investigations have been published that identify or analyse various critical pathways and biological processes through which the phytoalexin resveratrol has been shown to attenuate the metabolic dysfunctions, acute symptomatology and the consequential downstream pathologies related to type 2 diabetes. More recently, several clinical trials have confirmed resveratrol's potential to substantially enhance the therapeutic effects of the pharmaceutical metformin hydrochloride, particularly related to glucose management, insulin sensitivity and cardioprotection. Metformin is the most commonly prescribed type 2 diabetes treatment worldwide; consequently, any compound with the ability to safely and effectively augment its therapeutic effects warrants intensive investigation. This paper elucidates the principal modes of action that underly resveratrol's promising potential as an effective adjunct treatment for patients currently being administered metformin.

Resveratrol supplementation improves glycemic control in type 2 diabetes mellitus.

Resveratrol is a naturally occurring polyphenolic compound. Numerous animal studies have been reported on its wide-ranging beneficial effects in the biological system including diabetes mellitus (DM). We hypothesized, therefore, that oral supplementation of resveratrol would improve the glycemic control and the associated risk factors in patients with type 2 diabetes mellitus (T2DM). The present clinical study was therefore carried out to test the hypothesis. Sixty-two patients with T2DM were enrolled from Government Headquarters Hospital, Ootacamund, India, in a prospective, open-label, randomized, controlled trial. Patients were randomized into control and intervention groups. The control group received only oral hypoglycemic agents, whereas the intervention group received resveratrol (250 mg/d) along with their oral hypoglycemic agents for a period of 3 months. Hemoglobin A(1c), lipid profile, urea nitrogen, creatinine, and protein were measured at the baseline and at the end of 3 months. The results reveal that supplementation of resveratrol for 3 months significantly improves the mean hemoglobin A(1c) (means ± SD, 9.99 ± 1.50 vs 9.65 ± 1.54; P < .05), systolic blood pressure (mean ± SD, 139.71 ± 16.10 vs 127.92 ± 15.37; P < .05), total cholesterol (mean ± SD, 4.70 ± 0.90 vs 4.33 ± 0.76; P < .05), and total protein (mean ± SD, 75.6 ± 4.6 vs 72.3 ± 6.2; P < .05) in T2DM. No significant changes in body weight and high-density lipoprotein and low-density lipoprotein cholesterols were observed. Oral supplementation of resveratrol is thus found to be effective in improving glycemic control and may possibly provide a potential adjuvant for the treatment and management of diabetes.