This review covers the role of the nematode Caenorhabditis elegans as a whole organism model to study natural products for healthy aging. Literature between 2012 and 2023 was comprehensively analysed and is presented in a concise way.

In this study, an integrated in silico-in vitro approach was employed to discover natural products (NPs) active against SARS-CoV-2. The two SARS-CoV-2 viral proteases, i.e., main protease (M^pro) and papain-like protease (PL^pro), were selected as targets for the in silico study. Virtual hits were obtained by docking more than 140,000 NPs and NP derivatives available in-house and from commercial sources, and 38 virtual hits were experimentally validated in vitro using two enzyme-based assays. Five inhibited the enzyme activity of SARS-CoV-2 M^pro by more than 60% at a concentration of 20 μM, and four of them with high potency (IC₅₀ < 10 μM). These hit compounds were further evaluated for their antiviral activity against SARS-CoV-2 in Calu-3 cells. The results from the cell-based assay revealed three mulberry Diels-Alder-type adducts (MDAAs) from Morus alba with pronounced anti-SARS-CoV-2 activities. Sanggenons C (12), O (13), and G (15) showed IC₅₀ values of 4.6, 8.0, and 7.6 μM and selectivity index values of 5.1, 3.1 and 6.5, respectively. The docking poses of MDAAs in SARS-CoV-2 M^pro proposed a butterfly-shaped binding conformation, which was supported by the results of saturation transfer difference NMR experiments and competitive ¹H relaxation dispersion NMR spectroscopy.

The small and transparent nematode Caenorhabditis elegans is increasingly employed for phenotypic in vivo chemical screens. The influence of compounds on worm body fat stores can be assayed with Nile red staining and imaging. Segmentation of C. elegans from fluorescence images is hereby a primary task. In this paper, we present an image-processing workflow that includes machine-learning-based segmentation of C. elegans directly from fluorescence images and quantifies their Nile red lipid-derived fluorescence. The segmentation is based on a J48 classifier using pixel entropies and is refined by size-thresholding. The accuracy of segmentation was >90% in our external validation. Binarization with a global threshold set to the brightness of the vehicle control group worms of each experiment allows a robust and reproducible quantification of worm fluorescence. The workflow is available as a script written in the macro language of imageJ, allowing the user additional manual control of classification results and custom specification settings for binarization. Our approach can be easily adapted to the requirements of other fluorescence image-based experiments with C. elegans.

Ethnopharmacological relevanceEthnomedicinal fungi have a long history of use in the treatment of tumors and inflammatory disorders, pathologies often associated with dysregulated angiogenesis and immune-vascular interactions. However, their effects on endothelial cell functions relevant to angiogenesis and inflammation remain insufficiently characterized.Aim of the studyThe aim of this study was to identify the bioactive compounds from ethnopharmacologically relevant medicinal fungi by screening their ethanolic extracts for their effects on angiogenesis- and inflammation-related endothelial cell functions, followed by the identification and targeted isolation of these compounds using molecular networking and bioactivity-guided fractionation.Materials and MethodsTwenty-six ethanolic extracts from traditionally and popularly used macrofungi were screened in vitro for bioactivities related to angiogenesis and inflammation. Assays included endothelial cell proliferation and migration using human umbilical vein endothelial cells (HUVECs), as well as leukocyte adhesion to TNF-activated endothelial cells. Feature-based molecular networking was applied to correlate bioactivity with chemical profiles. Bioactive constituents from Inonotus obliquus were isolated and evaluated for anti-proliferative activity.ResultsEleven fungal extracts significantly inhibited HUVEC proliferation at 25 µg/µL, with Fomitopsis betulina and Inonotus obliquus showing the highest activity. None of the extracts affected endothelial migration, and only one inhibited leukocyte adhesion. Molecular networking revealed a rich and diverse occurrence of lanostane-type triterpenes (LTTs) in all anti-proliferative extracts. Chemical investigation of Inonotus obliquus led to the isolation of several LTTs, of which lanosterol and inotodiol inhibited HUVEC proliferation with IC50 values of 2.1 µM and 9.1 µM, respectively, whereas more oxidized LTTs showed reduced activity.ConclusionsExtracts rich in LTTs exhibit pronounced anti-proliferative effects on endothelial cells, supporting the traditional use of certain polypores in conditions involving aberrant angiogenesis.

Ethnomedicinal fungi have a long history of use in the treatment of tumors and inflammatory disorders, pathologies often associated with dysregulated angiogenesis and immune-vascular interactions. However, their effects on endothelial cell functions relevant to angiogenesis and inflammation remain insufficiently characterized. The aim of this study was to identify the bioactive compounds from ethnopharmacologically relevant medicinal fungi by screening their ethanolic extracts for their effects on angiogenesis- and inflammation-related endothelial cell functions, followed by the identification and targeted isolation of these compounds using molecular networking and bioactivity-guided fractionation. Twenty-six ethanolic extracts from traditionally and popularly used macrofungi were screened in vitro for bioactivities related to angiogenesis and inflammation. Assays included endothelial cell proliferation and migration using human umbilical vein endothelial cells (HUVECs), as well as leukocyte adhesion to TNF-activated endothelial cells. Feature-based molecular networking was applied to correlate bioactivity with chemical profiles. Bioactive constituents from Inonotus obliquus were isolated and evaluated for anti-proliferative activity. In the three assays performed, the inhibition of endothelial cell proliferation was observed as the most consistent and robust effect. Eleven fungal extracts significantly inhibited HUVEC proliferation at 25 μg/mL, with Fomitopsis betulina and Inonotus obliquus showing the highest activity. None of the extracts affected endothelial migration, and only one inhibited leukocyte adhesion. Molecular networking revealed a rich and diverse occurrence of lanostane-type triterpenes (LTTs) in all anti-proliferative extracts. Chemical investigation of Inonotus obliquus led to the isolation of several LTTs, of which lanosterol and inotodiol inhibited HUVEC proliferation with IC₅₀ values of 2.1 μM and 9.1 μM, respectively, whereas more oxidized LTTs showed reduced activity. Many extracts enriched in LTTs exhibit pronounced anti-proliferative effects on endothelial cells, suggesting a potential modulation of angiogenesis-related processes and thereby supporting the traditional use of certain polypores in conditions involving aberrant angiogenesis.