Guanhui Liu

Cordycepin is a key active component of Cordyceps militaris, but the molecular mechanism underlying temperature-regulated biosynthesis remains unclear. In this study, Cordyceps militaris strain KN-1 was used as experimental material, with low-temperature (15 °C), control (20 °C), and high-temperature (25 °C) treatments applied during the fruiting body stage. Transcriptomics, untargeted metabolomics, weighted gene co-expression network analysis (WGCNA), and Reverse Transcription quantitative PCR (RT-qPCR) validation were integrated to elucidate the molecular mechanism of temperature-mediated cordycepin biosynthesis. The results showed that 25 °C increased fruiting body cordycepin content by 84%, while 15 °C reduced it. Transcriptomic analysis identified differentially expressed genes (DEGs) enriched in transmembrane transport and fatty acid metabolism, and untargeted metabolomics revealed differential metabolites (DAMs) enriched in lipids and organic acids, indicating that temperature primarily affects Cordyceps militaris membrane function. WGCNA showed that the MEblue module was positively correlated with cordycepin (r = 0.93), with Major Facilitator Superfamily (MFS) members accounting for the highest proportion (47.1%) that may affect cordycepin transmembrane transport. Multi-omics analysis indicated that high temperature promotes cordycepin accumulation through the synergistic regulation of multiple pathways: upregulating genes in the pentose phosphate pathway, purine metabolism, and cordycepin biosynthetic gene cluster (Cns1–Cns3), increasing protective agent pentostatin content, downregulating cordycepin-degrading genes, and enhancing cordycepin transmembrane transport. This study clarifies the molecular mechanism of temperature-mediated cordycepin accumulation, providing a theoretical basis for improving cordycepin production via temperature regulation, optimizing Cordyceps militaris strain quality, and facilitating efficient industrial production.

Mulberry leaves contain polysaccharides, phenols, alkaloids, and other active ingredients which have medicinal and edible value. In this study, fermented mulberry leaf powder was prepared by solid-state fermentation using Pediococcus pentosaceus JC30. The effects of the fermentation on the phytochemical, flavor characteristics, phenolics, and antioxidant activity of mulberry leaves were studied. The results showed that the content of γ-aminobutyric acid in fermented mulberry leaf powder (FMLP) increased by 6.73-fold and the content of phytic acid decreased by 11.16%. Ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis showed that the fermentation of Pediococcus pentosaceus JC30 altered the phenolic composition of mulberry leaves, increasing the total free phenolic content by 88.43%. In particular, the contents of free phenols such as leucocyanidin, myricetin, and quercetin increased significantly and were positively correlated with antioxidant capacity. The fermentation of Pediococcus pentosaceus JC30 significantly enhanced the scavenging ability of DPPH free radicals, hydroxyl radicals, and the total reducing ability of mulberry leaves. Gas chromatography ion mobility spectrometry (GC-IMS) analysis showed that FMLP has an intense fruity and floral aroma, while having less grassy and earthy odor. The fermentation improved the phytochemical, flavor, and nutritional value of mulberry leaves, which provides more possibilities for the development of mulberry leaf products outside the sericulture industry.

Bombyx batryticatus is the dried body of silkworm (Bombyx mori Linnaeus) larvae infected with Beauveria bassiana. It is widely used in traditional Chinese medicine for treating convulsions, epilepsy, and hyperglycemia. In this study, Bombyx batryticatus and its extract were prepared. The total reducing power, hydroxyl radical scavenging and superoxide anion radical scavenging activities, as well as the α-glucosidase inhibitory activity of Bombyx batryticatus extract were superior to those of normal silkworm larvae extract. Among them, the IC₅₀ value of Bombyx batryticatus extract for α-glucosidase was 5.76 mg/mL, while that of normal silkworm larvae extract was 7.0 mg/mL. Untargeted metabolomic analysis was employed to compare the material composition of normal silkworm larvae and Bombyx batryticatus. The results revealed 101 metabolic differences between the two groups, including a significant increase in fatty acids and their derivatives in the Bombyx batryticatus extract. Further separation and purification of the Bombyx batryticatus extract were performed using solvents of varying polarity. The chloroform fraction exhibited the highest inhibitory activity against α-glucosidase, with an IC₅₀ value of 0.217 mg/mL. LC-MS further identified compounds in the chloroform fraction, suggesting that those alkaloids, fatty acids, and their derivatives may be responsible for its strong α-glucosidase inhibitory activity. This study elucidates the material basis underlying the pharmacological effects of Bombyx batryticatus, particularly its hypoglycemic components, thereby providing critical experimental support for its future development and application in medicine.

Gluten-free rice bread made from japonica rice finds challenge in achieving a good shape and structure, presenting a significant obstacle in the baking industry. This study aims to improve the quality of rice bread with japonica rice flour by hot extrusion treatment (without additives). The effects of extrusion on the amylose content, gelatinization degree, hydration capacity, short-range molecular ordering, and microstructure of japonica rice flour were investigated. The results show that the amylose content of the extruded flour increased by 12.43% and the gelatinization degree of it increased by 13.23 times, showing disrupted starch granules, numerous pores, and a better hydration capacity. The addition of extruded flour improved the overall viscoelasticity of the batter. Compared to the control group, the specific volume and porosity of the optimized rice bread were increased by 19.46% and 61.92%, respectively. The gas cell density was increased by 4.63 times, and the average gas cell area of rice bread was reduced by 47.14%. The correlations among the raw material properties of rice flour, the batter properties, and the quality of rice bread products were revealed by principal component analysis. This study demonstrates that the addition of moderate amounts of extruded japonica rice flour could improve the quality of rice bread products.

Antibiotic resistance genes (ARGs) have become recognized contaminants and pose a high public health risk. The animal gut microbiota is a reservoir of ARGs, but the knowledge of the origin and dissemination of ARGs remains unclear. In this study, we provide a comprehensive profile of ARGs and mobile genetic elements in the gut microbiota from 30 bovines to study the impact of modern antibiotics on resistance. A total of 42 ARG types were detected by annotating the metagenomic sequencing data from Comprehensive Antibiotic Resistance Database (CARD). We found that the diversity and abundance of ARGs in individual yaks were significantly lower than those in dairy and beef cattle ( p < 0.0001). The results of heat map and single nucleotide polymorphism clustering suggest that ARGs from dairy and beef cattle are more similar, whereas those from yaks cluster separately. The long-term use of antibiotics may contribute to this difference, suggesting that antibiotic consumption is the main cause of ARG prevalence. Furthermore, abundant insertions were also found in this study, signifying a strong potential for horizontal transfer of ARGs among microbes, especially pathogens.

In the present study, the hypoglycemic effects of wheat bran alkyresorcinols (ARs) were investigated in type 2 diabetes mellitus (T2DM) mice induced by a high-fat/high-sucrose diet (HFSD) combined with low dose streptozotocin (STZ). After the consumption of 5 mg kg⁻¹ d⁻¹ acarbose (positive control) and different doses of wheat bran ARs (50, 200 and 500 mg kg⁻¹ d⁻¹) for 4 weeks, the fasting blood glucose (FBG) levels in T2DM mice were found to be reduced significantly (p < 0.05), and the effects of 200 and 500 mg kg⁻¹ d⁻¹ administration were better than that of 50 mg kg⁻¹ d⁻¹. The results of the oral glucose tolerance test (OGTT) also showed that both acarbose and AR administration significantly increased the glucose tolerance of the T2DM mice. Then, the fasting serum insulin levels (FINS) were significantly reduced by AR treatment, and the effect of 500 mg kg⁻¹ d⁻¹ AR administration was better than that of 5 mg kg⁻¹ d⁻¹ acarbose. The profile of plasma lipids was analyzed simultaneously, and the results showed that the contents of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) were significantly decreased, while the content of high-density lipoprotein cholesterol (HDL-C) was increased significantly after 200 and 500 mg kg⁻¹ d⁻¹ AR treatment (p < 0.05). Furthermore, 200 and 500 mg kg⁻¹ d⁻¹ ARs significantly increased the content of hepatic glycogen and the activity of glucokinase (p < 0.01) in T2DM mice. The relative mRNA levels of glucose transporter 2 (GLUT2) in the liver tissue were increased markedly in 200 and 500 mg kg⁻¹ d⁻¹ AR treatment groups (p < 0.01), and the relative mRNA levels of glucose transporter 4 (GLUT4) in the epididymal adipose tissue were increased significantly in all AR treatment groups, especially significantly higher than acarbose (p < 0.01). Histological analyses revealed that treatment with ARs exerted a protective role on pancreatic β-cells. The results indicated that ARs could be an effective hypoglycemic active ingredient in whole grain diets.