Research progress on components and mechanisms of neurotoxicity induced by traditional Chinese medicine

The analysis of raw and processed Polygonatum kingianum saponins and stimulatory mechanism in Caenorhabditis elegans

Polygonati Rhizoma, a Chinese medicine often used in the clinic, can irritate the tongue and throat, so it must be processed before use. Polygonati Rhizoma contains a variety of chemical components, with saponins being one of the main active ingredients. Saponins can be highly irritating to human mocous membranes and have toxicity. In this study, total saponins were extracted from raw and processed Polygonati Rhizoma and detected by UPLC-Q-TOF-MS to identify their constituents. A total of 46 saponins were detected in TSRPR(total saponins of raw Polygonati Rhizoma), TSSPR(total saponins of steamed Polygonati Rhizoma) and TSWPR(total saponins of Polygonati Rhizoma steamed in wine). Of these, 9 compounds that were present in TSRPR were not detected in TSSPR and TSWPR. C.elegans was used as a model animal to study the neurotoxic effect and its mechanisms. TSRPR was found to have neurotoxic effects on C.elegans, but TSSPR and TSWPR had no adverse effects on the nematodes. The disappearance of the irritant effect of raw Polygonati Rhizoma after processing might be related to the changes in the composition of saponins, and the main reason might be the structural transformation of saponins. In particular, the sugar chains of some highly irritating saponins may have been removed or highly irritating saponins isomerized into weakly irritating saponins. The mechanisms of neurotoxic effects on C.elegans may include upregulation of ced-3 and egl-1 expression to promote apoptosis, damage to GABAergic and cholinergic neurons, downregulation of the GABA transmitter receptor genes ggr-1 and gab-1, and a decrease in glutamate levels that impairs nerve signal transmission.

Screening tools to evaluate the neurotoxic potential of botanicals: building a strategy to assess safety

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This paper outlines the selection of NAMs, including in vitro assays using primary rat cortical neurons, zebrafish embryos, and Caenorhabditis elegans. These assays aim to assess neurotoxic endpoints such as neuronal activity and behavioral responses. Microelectrode array recordings of rat cortical neurons provide insights into the impact of botanical extracts on neuronal function, while the zebrafish embryos and C. elegans assays evaluate neurobehavioral responses. The paper also provides an account of the selection of botanical case studies based on expert judgment and existing neuroactivity/toxicity information. The proposed battery of assays will be tested with these case studies to evaluate their utility for neurotoxicity screening.

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The complexity of botanicals necessitates the use of multiple NAMs for effective neurotoxicity screening. This paper discusses the evaluation of methodologies to develop a robust framework for evaluating botanical safety, including complex neuronal models and key neurodevelopmental process assays. It aims to establish a comprehensive screening framework.

First genome assembly and annotation of Sanghuangporus weigelae uncovers its medicinal functions, metabolic pathways, and evolution

Sanghuangporus, also known as "Sanghuang" in China, is a well-known genus of traditional Chinese medicinal macrofungi. To make more effective use of Sanghuangporus resources, we completed the first genome assembly and annotation of a monokaryon strain of S. weigelae in the present study. A 33.96-Mb genome sequence was assembled as 13 contigs, leading to prediction of 9377 protein-coding genes. Phylogenetic and average nucleotide identity analyses indicated that the S. weigelae genome is closely related to those of other Sanghuangporus species in evolutionary tree, which clustered in one clade. Collinearity analysis revealed a high level of collinearity of S. weigelae with S. baumii, S. vaninii, and S. sanghuang. Biosynthesis pathways potentially involved in medicinal properties, including terpenoid and polysaccharide synthesis, were identified in S. weigelae, while polysaccharides were identified as the main medicinal metabolites in S. weigelae, with flavonoids more important in Sanghuangporus than other medicinal mushroom groups. Genes encoding 332 carbohydrate-active enzymes were identified in the S. weigelae genome, including major glycoside hydrolases and glycosyltransferases predicted, revealing the robust lignocellulose degradation capacity of S. weigelae. Further, 130 genes, clustered in seven classes were annotated to encode cytochromes P450 in the S. weigelae genome. Overall, our results reveal the remarkably medicinal capacity of S. weigelae and provide new insights that will inform the study of evolution and medicinal application of S. weigelae. The data are a reference resource for the formulation of scientific and rational ecological protection policies for Sanghuangporus species.