Chitosan-Coated Cinnamon/Oregano-Loaded Solid Lipid Nanoparticles to Augment 5‑Fluorouracil Cytotoxicity for Colorectal Cancer: Extract Standardization, Nanoparticle Optimization, and Cytotoxicity Evaluation

This study aimed to coat lipid-based nanocarriers with chitosan to encapsulate nutraceuticals, minimize opsonization, and facilitate passive-targeting. Phase one was concerned with standardization according to the World Health Organization. Qualitative analysis using liquid chromatography–high-resolution mass spectrometry (LC-HRMS/MS) investigated the active constituents, especially reported cytotoxic agents. Cinnamaldehyde and rosmarinic acid were selected to be quantified using high-performance liquid chromatography. Phase two was aimed to encapsulate both extracts in solid lipid nanoparticles (core) and chitosan (shell) to gain the advantages of both materials properties. The developed experimental model suggested an optimum formulation with 2% lipid, 2.3% surfactant, and 0.4% chitosan to achieve a particle size of 254.77 nm, polydispersity index of 0.28, zeta potential of +15.26, and entrapment efficiency percentage of 77.3% and 69.1% for cinnamon and oregano, respectively. Phase three was focused on the evaluation of cytotoxic activity unencapsulated/encapsulated cinnamon and oregano extracts with/without 5-fluorouracil on HCT-116 cells. This study confirmed the success of the suggested combination with 5-fluorouracil for treating human colon carcinoma with a low dose leading to decreasing side effects and allowing uninterrupted therapy

Secondary metabolites from fungal endophytes of <i>Solanum nigrum</i>

<p>Three endophytic fungi, <i>Aspergillus</i> sp. (SNFSt), <i>Aspergillus</i> sp. (SNFL) and <i>Lasiodiplodia theobromae</i> (SNFF) were isolated from stems, leaves and fruits of <i>Solanum nigrum</i> L, respectively. The static fermentation of the three fungal strains led to the characterization of nine known metabolites (<b>1</b>–<b>9)</b> using HRESIMS and NMR analyses.</p

Application of Ultraviolet‑C Radiation and Gaseous Ozone for Microbial Inactivation on Different Materials

With the advent of the COVID-19 pandemic, there has been a global incentive for applying environmentally sustainable and rapid sterilization methods, such as ultraviolet-C radiation (UVC) and ozonation. Material sterilization is a requirement for a variety of industries, including food, water treatment, clothing, healthcare, medical equipment, and pharmaceuticals. It becomes inevitable when devices and items like protective equipment are to be reused on/by different persons. This study presents novel findings on the performance of these sterilization methods using four microorganisms (Escherichia coli,Staphylococcus aureus,Candida albicans, and Aspergillus fumigatus) and six material substrates (stainless steel, polymethyl methacrylate, copper, surgical facemask, denim, and a cotton-polyester fabric). The combination of both ozone and UVC generally yields improved performance compared to their respective applications for the range of materials and microorganisms considered. Furthermore, the effectiveness of both UVC and ozone was higher when the fungi utilized were smeared onto the nonabsorbent materials than when 10 μL droplets were placed on the material surfaces. This dependence on the contaminating liquid surface area was not exhibited by the bacteria. This study highlights the necessity of adequate UVC and ozone dosage control as well as their synergistic and multifunctional attributes when sterilizing different materials contaminated with a wide range of microorganisms

Herbicidins from <i>Streptomyces</i> sp. CB01388 Showing Anti-<i>Cryptosporidium</i> Activity

A high-content imaging assay was used to screen the fraction collection of the Natural Product Library at The Scripps Research Institute for inhibitors of <i>Cryptosporidium parvum</i>. A chemical investigation of one strain, <i>Streptomyces</i> sp. CB01388, resulted in the isolation of six herbicidins (<b>1</b>–<b>6</b>), one of which is new (herbicidin L, <b>1</b>). Five of the six herbicidins (<b>1</b>–<b>3</b>, <b>5</b>, <b>6</b>) showed moderate inhibitory activity against <i>C. parvum</i>, with <b>1</b> and <b>6</b> comparable to the FDA-approved drug nitazoxanide, and <b>2</b>-<b>6</b> showed no toxicity to the host HCT-8 cells and human HEK293T and HepG2 cells. These findings highlight the herbicidin scaffold for anti-<i>Cryptosporidium</i> drug development

Chaxapeptin, a Lasso Peptide from Extremotolerant <i>Streptomyces leeuwenhoekii</i> Strain C58 from the Hyperarid Atacama Desert

Lasso peptides are ribosomally synthesized and post-translationally modified peptides (RiPPs) that possess a unique “lariat knot” structural motif. Genome mining-targeted discovery of new natural products from microbes obtained from extreme environments has led to the identification of a gene cluster directing the biosynthesis of a new lasso peptide, designated as chaxapeptin <b>1</b>, in the genome of <i>Streptomyces leeuwenhoekii</i> strain C58 isolated from the Atacama Desert. Subsequently, <b>1</b> was isolated and characterized using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance methods. The lasso nature of <b>1</b> was confirmed by calculating its nuclear Overhauser effect restraint-based solution structure. Chaxapeptin <b>1</b> displayed a significant inhibitory activity in a cell invasion assay with human lung cancer cell line A549

Biosynthetic Potential-Based Strain Prioritization for Natural Product Discovery: A Showcase for Diterpenoid-Producing Actinomycetes

Natural products remain the best sources of drugs and drug leads and serve as outstanding small-molecule probes to dissect fundamental biological processes. A great challenge for the natural product community is to discover novel natural products efficiently and cost effectively. Here we report the development of a practical method to survey biosynthetic potential in microorganisms, thereby identifying the most promising strains and prioritizing them for natural product discovery. Central to our approach is the innovative preparation, by a two-tiered PCR method, of a pool of pathway-specific probes, thereby allowing the survey of all variants of the biosynthetic machineries for the targeted class of natural products. The utility of the method was demonstrated by surveying 100 strains, randomly selected from our actinomycete collection, for their biosynthetic potential of four classes of natural products, aromatic polyketides, reduced polyketides, nonribosomal peptides, and diterpenoids, identifying 16 talented strains. One of the talented strains, <i>Streptomyces griseus</i> CB00830, was finally chosen to showcase the discovery of the targeted classes of natural products, resulting in the isolation of three diterpenoids, six nonribosomal peptides and related metabolites, and three polyketides. Variations of this method should be applicable to the discovery of other classes of natural products