Background: Cinnamomum longepaniculatum (Gamble) N. Chao ex H. W. Li, whose leaves produce essential oils, is a traditional Chinese medicine and economically important tree species. In our study, two C. longepaniculatum varieties that have significantly different essential oil contents and leaf phenotypes were selected as the materials to investigate secondary metabolism. Result: The essential oil content and leaf phenotypes were different between the two varieties. When the results of both transcriptome and metabolomic analyses were combined, it was found that the differences were related to phenylalanine metabolic pathways, particularly the metabolism of flavonoids and terpenoids. The transcriptome results based on KEGG pathway enrichment analysis showed that pathways involving phenylpropanoids, tryptophan biosynthesis and terpenoids significantly differed between the two varieties; 11 DEGs (2 upregulated and 9 downregulated) were associated with the biosynthesis of other secondary metabolites, and 12 DEGs (2 upregulated and 10 downregulated) were related to the metabolism of terpenoids and polyketides. Through further analysis of the leaves, we detected 196 metabolites in C. longepaniculatum. The abundance of 49 (26 downregulated and 23 upregulated) metabolites differed between the two varieties, which is likely related to the differences in the accumulation of these metabolites. We identified 12 flavonoids, 8 terpenoids and 8 alkaloids and identified 4 kinds of PMFs from the leaves of C. longepaniculatum. Conclusions: The combined results of transcriptome and metabolomic analyses revealed a strong correlation between metabolite contents and gene expression. We speculate that light leads to differences in the secondary metabolism and phenotypes of leaves of different varieties of C. longepaniculatum. This research provides data for secondary metabolite studies and lays a solid foundation for breeding ideal C. longepaniculatum plants.

Puerarin (Pue) is a kind of isoflavone compound extracted from Pueraria lobata, which has significant antioxidant activity. Excessive use of acetaminophen (APAP) can cause oxidative stress in the liver and eventually lead to acute liver injury. The purpose of this study was to investigate the protective effect and the mechanism of puerarin on APAP‐induced liver oxidative damage. In in vitro experiments, puerarin significantly increased the cell activity of HepG2 cells, reduced the ROS accumulation, alleviated the oxidative damage and mitochondrial dysfunction. In in vivo studies, our results showed that puerarin enhanced antioxidant activity and alleviated histopathological damage. Further studies showed that puerarin decreased the expression of Keap1, promoted the nuclear migration of Nrf2, and up‐regulated the expression of GCLC, GCLM, HO‐1 and NQO1. This study demonstrated that puerarin can protect APAP‐induced liver injury via alleviating oxidative stress and mitochondrial dysfunction by affecting the nuclear migration of Nrf2 via inhibiting Keap1.

Brasenia schreberi is a widely consumed aquatic plant, yet the knowledge regarding its bioactive components, particularly polysaccharides, remains limited. Therefore, this study aimed to optimize the extraction process of polysaccharides from B. schreberi using the response surface method (RSM). Additionally, we characterized the polysaccharides using various methods and assessed their antioxidant capabilities both in vitro and in vivo, employing cell cultures and Caenorhabditis elegans. Furthermore, these polysaccharides were incorporated into a unique yogurt formulation. Our findings demonstrated that hot water extraction was the most suitable method for extracting polysaccharides from B. schreberi, yielding samples with high sugar content, significant antioxidant capacity, and a well-defined spatial structure. Moreover, pectinase was employed for polysaccharide digestion, achieving an enzymolysis rate of 10.02% under optimized conditions using RSM. Notably, the results indicated that these polysaccharides could protect cells from oxidative stress by reducing apoptosis. Surprisingly, at a concentration of 250 μg/mL, the polysaccharides significantly increased the survival rate of C. elegans from 31.05% to 82.3%. Further qPCR results revealed that the polysaccharides protected C. elegans by up-regulating the daf-16 gene and down-regulating mTOR and insulin pathways, demonstrating remarkable antioxidant abilities. Upon addition to the yogurt, the polysaccharides significantly enhanced the water retention, viscosity, and viability of lactic acid bacteria. These outcomes underscore the potential of polysaccharides from B. schreberi as a valuable addition to novel yogurt formulations, thereby providing additional theoretical support for the utilization of B. schreberi.

Polyvinyl alcohol (PVA)/chitosan (CS)-based films incorporated with Antrodia cinnamomea polysaccharide (ACP) and tea tree essential oil (TTEO) were developed using a solution casting method. The physicochemical, bioactive, and structural attributes, as well as the effects of these films on post-harvest ‘Yuluxiang’ pears, were assessed. The results demonstrated strong interactions among all functional components. The integration of ACP reinforced the mechanical properties of PVA/CS-based films, whereas the combined incorporation of ACP/TTEO enhanced water resistance, ultraviolet-light shielding ability, and barrier performance against oxygen and water vapor. Contact angle measurements showed that the PVA/CS/ACP/TTEO composite film exhibited superior wettability and adhesion to pear surfaces. Furthermore, the PVA/CS/ACP/TTEO composite film exhibited potent antibacterial activity, recording 99.99% inhibition against Staphylococcus aureus and 99.91% against Escherichia coli. TGA and DTG analyses suggested that ACP improved the thermal stability and restricted the film’s degradation rate. Antioxidant assays revealed that the incorporation of ACP and TTEO markedly elevated the antioxidant ability of the PVA/CS-based film. After 21 days of storage, the PVA/CS/ACP/TTEO composite film effectively maintained firmness, titratable acidity, vitamin C levels, and the activities of superoxide dismutase and catalase in post-harvest pears. Moreover, the composite film delayed fruit yellowing and oiliness, lowered the accumulation of hydrogen peroxide and malondialdehyde, and significantly reduced microbial counts (p < 0.05). This study demonstrates that the fabricated PVA/CS/ACP/TTEO composite film possesses the ability to extend the shelf life of perishable fruits under ambient storage conditions.

Camphora longepaniculata is an important economic crop renowned for its rich volatile terpene compounds. Terpene synthases (TPS) are key enzymes in the biosynthesis of these compounds, playing significant roles in plant growth, development, and secondary metabolism. In this study, a total of 86 TPS genes were identified in Camphora longepaniculata, which were classified into five groups based on their evolutionary relationships. Analysis of cis-regulatory elements revealed associations between TPS genes and processes related to plant growth, development, and environmental stress responses. Gene Ontology (GO) enrichment analysis indicated that these TPS genes are predominantly linked to various enzymatic activities. Furthermore, analysis of duplication events revealed that tandem duplications (TD) and whole genome duplications (WGD) are major driving forces in the evolution of the TPS gene family. Notably, 18 TPS genes were found to be upregulated in high essential oil content varieties of Camphora longepaniculata. These findings lay a solid foundation for further exploration of the functions of TPS genes in Camphora longepaniculata.