Antimicrobial Efficacy of Methylated Lac Dye, an Anthraquinone Derivative

Antibiotic Isoflavonoids, Anthraquinones, and Pterocarpanoids from Pigeon Pea (Cajanus cajan L.) Seeds against Multidrug-Resistant Staphylococcus aureus

Cajanus cajan L. (pigeon pea, locally known in the Philippines as kadios) seed is a functional food with health benefits that extend beyond their nutritional value. C. cajan seeds contain highly diverse secondary metabolites with enriched beneficial properties, such as antibacterial, anticancer, and antioxidant activities. However, the antibacterial activities of secondary metabolites from Philippine-grown C. cajan, against multidrug-resistant Staphylococcus aureus have not been thoroughly described. Here, we investigated the in vitro antibacterial properties of C. cajan seed against multidrug-resistant S. aureus ATCC BAA-44 (MDRSA) and three other S. aureus strains (S. aureus ATCC 25923, S. aureus ATCC 6538, and coagulase-negative S. aureus) and, subsequently, identified the antibiotic markers against S. aureus strains using mass spectrometry. Secondary metabolites from C. cajan seeds were extracted using acetone, methanol, or 95% ethanol. Antibacterial screening revealed antibiotic activity for the C. cajan acetone extract. Bioassay-guided purification of the C. cajan acetone extract afforded three semi-pure high-performance liquid chromatography (HPLC) fractions exhibiting 32–64 µg/mL minimum inhibitory concentration (MIC) against MDRSA. Chemical profiling of these fractions using liquid chromatography mass spectrometry (LCMS) identified six compounds that are antibacterial against MDRSA. High-resolution mass spectrometry (HRMS), MS/MS, and dereplication using Global Natural Products Social Molecular Networking (GNPS)™, and National Institute of Standards and Technology (NIST) Library identified the metabolites as rhein, formononetin, laccaic acid D, crotafuran E, ayamenin A, and biochanin A. These isoflavonoids, anthraquinones, and pterocarpanoids from C. cajan seeds are potential bioactive compounds against S. aureus, including the multidrug-resistant strains.

Vishaghn Dhoop, Nano-Scale Particles with Detoxifying Medicinal Fume, Exhibits Robust Anti-Microbial Activities: Implications of Disinfection Potentials of a Traditional Ayurvedic Air Sterilization Technique

The rapidly increasing global burden of healthcare associated infections (HAI) is resulting in proportionate increase in chemical disinfection in healthcare settings, adding an extra burden of environmental toxicity. Therefore, alternative disinfection techniques with less or no adverse side-effects need to be explored. In this regard, ayurvedic 'dhoopan' technique involving slow combustion of medicinal herbs, minerals and animal products hold great promise. In this study, dhoopan of a traditionally defined ayurvedic medicinal mix, 'Vishaghn Dhoop' (VD) has been assessed for its anti-microbial potentials against both Gram-positive and negative pathogenic bacteria, Mycobacterium and pathogenic fungus, Candida albicans. Fume generated from slow combustion of VD was subjected to physico-chemical characterization and was assessed for anti-microbial effects. VD fume contained particles of 354 ± 84 nm size, laden with anti-microbial metabolites. On agar plates, VD fumigation reduced bacterial growth by 13 - 38%. Liquid culture aeration with VD fume inhibited bacterial growth by 50 - 85%, and fungal growth by 80%. In real life settings (in vivo), un-sanitized rooms fumigated with VD fumes for 30 min reduced the environmental microbial loads by 10 folds. In addition, the safety of VD fumigation was evaluated through in vitro cytotoxicity assay on human lung epithelial (A549) cells. Cells exposed to media-collected VD fumes for 24 h exhibited normal cyto-safety profile. Collectively, these observations provide scientific evidence in support of a traditional technique of disinfection, which can be fine-tuned to have implications in clinical, healthcare and food industry where, disinfection is a prime requirement.

Novel Hybrid Polymer Composites Based on Anthraquinone and Eco-Friendly Dyes with Potential for Use in Intelligent Packaging Materials

This study aimed to present the influence of bio-based and anthraquinone dyes and their combinations on the optical properties of ethylene-propylene (EPM) composites after thermo-oxidative and climatic aging. Therefore, the chosen polymer was filled with a natural, plant-origin flavonoid—quercetin, and with two commercial anthraquinone dyes (C.I. Solvent Yellow 163 and C.I. Solvent Red 207). The manufactured polymer composites were subjected to accelerated aging tests: weathering and thermo-oxidation, respectively. Examination of the materials’ properties indicated that the combination of synthetic and natural dyes can result in better resistance to oxidizing agents and higher thermal stability of ethylene-propylene products. Moreover, color change of quercetin-containing samples due to exposure to simulated atmospheric conditions could be a promising solution for use as aging indicators in intelligent packaging materials that will inform about the ongoing degradation process. Another interesting finding is that these samples exhibited good fungistatic activity against Candida albicans yeast and Aspergillus niger mold. Overall, this novel solution based on hybrid polymer composites containing natural and commercial dyes is a more environmentally friendly alternative to traditional materials used in the plastic packaging industry with better and more desirable properties.

Regio-specific biotransformation of alizarin to alizarin methoxide with enhanced cytotoxicity against proliferative cells

Alizarin has been reported to have an antigenotoxic activity along with an inhibitory effect on the tumor cell growth of human colon carcinoma cells. Alizarin was biotransformed into an O-methoxide derivative using O-methyltransferase from Streptomyces avermitilis MA4680 (SaOMT2) to enhance its bioefficacy. The biotransformed product was extracted, purified, and characterized using various chromatographic and spectroscopic analyses, and confirmed to be an alizarin 2-O-methoxide. The antiproliferative activity of the compound against gastric cancer cells (AGS), uterine cervical cancer (Hela), liver cancer (HepG2), and normal cell lines was investigated. Alizarin 2-O-methoxide showed an inhibitory effect on all three cancer-cell lines at very low concentrations, from 0.078 µM, with no cytotoxicity against 267B1 (human prostate epithelial) and MRC-5 (normal human fetal lung fibroblast).

Lac water extract inhibits IFN-γ signaling through JAK2-STAT1-IRF1 axis in human melanoma

Interferon-γ (IFN-γ) is a cytokine that plays an important role in the host defense of infectious diseases and in immune surveillance during tumor development.