Tea Research Institute

Di-(2-ethylhexyl) phthalate (DEHP) is a prevalent plasticizer that has been demonstrated to induce male reproductive toxicity through the disruption of spermatogenesis. Icariin (ICA), a bioactive compound derived from the traditional Chinese medicine Epimedium, holds significant potential in the treatment of male infertility. However, its clinical utilization is constrained by low absorption and fast metabolism upon oral administration. Herein, we first developed ICA-loaded chondroitin sulfate (CS) and polyvinylpyrrolidone K30 (PVP K30) microneedle (MN) patches (ICA MNs) for treating DEHP-induced testicular dysfunction. The results found that ICA MNs significantly reduced DEHP-induced oxidative stress and apoptosis in GC-1 cells by modulating the Keap1/Nrf2/HO-1 pathway. In addition, ICA MNs mitigated DEHP-induced testicular damage, sperm irregularities, and blood-testis barrier impairment in rats, surpassing the efficacy of oral ICA treatment. Proteomic analysis indicated a restoration of the testicular proteome toward normal levels after ICA MN treatment. Comprehensive safety assessments revealed no adverse systemic effects, highlighting the biocompatibility of ICA MNs. These findings suggest ICA MNs as a promising therapeutic approach for male infertility associated with DEHP exposure, offering targeted and efficient transdermal delivery.

Tea cultivar genotype plays a critical role in shaping rhizosphere microbiome assembly, yet the underlying mechanisms remain poorly understood. This study employed a controlled pot experiment with five widely cultivated Chinese tea cultivars (Camellia sinensis) to investigate how cultivar-specific variation influences rhizosphere microbial communities and their assembly processes. Rhizosphere soil microbiomes (bacterial and fungal communities) and metabolomes were characterized using 16S rRNA and ITS2 amplicon sequencing combined with untargeted metabolomics. Significant differences in rhizosphere metabolite composition, primarily organic acids, fatty acids, and carbohydrates, were observed among cultivars, which corresponded to distinct bacterial and fungal community structures. Redundancy analysis (RDA) revealed that rhizosphere metabolites explained 19.87% of bacterial and 21.63% of fungal community compositional variation, second only to soil physicochemical properties. Neutral community model and modified stochasticity ratio analyses indicated that microbial assembly across cultivars was predominantly deterministic, and rhizosphere metabolite profiles were strongly correlated with microbial community structure. Notably, arbuscular mycorrhizal fungi made up about 11% of the fungal communities in minimally fertilized pot systems, contrasting sharply with their near-absence in conventionally managed systems plantations. These findings demonstrate that tea cultivar genotype significantly shapes rhizosphere microbiome assembly through metabolic differentiation, providing a theoretical foundation for integrating microbiome considerations into tea breeding programs and developing cultivar-specific management strategies.

As widely consumed beverage, the stability is crucial to the quality and shelf life of tea beverage. In this study, whey protein isolate (WPI)-beta-cyclodextrin (β-CD) was added to investigate its effect on the stability of jasmine tea beverage by pH, thermal and storage stability. The results showed tea beverages under neutral and acidic conditions are more stable than those under alkaline conditions, and have higher antioxidant activity and total phenol retention rate. The storage stability experiments (25 °C for 30 d, and 4 °C for 150 d) showed the higher the storage temperature, the less stable the tea beverages were. WPI-β-CD addition was beneficial to delaying the degradation of tea polyphenols in the tea beverages, delayed by 6.41% after 150 d of storage. This study provides a theoretical basis for the development of new tea beverage products and the wide application of EGCG.

Pile fermentation is a crucial process for developing the characteristic mellow taste and aged aroma of dark tea, yet the internal quality transformation mechanism of this process is still unclear. This study employed a high-sensitivity analytical platform based on gas chromatography–mass spectrometry (GC-MS) to systematically investigate the dynamic interplay between key chemical components, enzyme activities, and volatile compounds during the pile fermentation of primary dark tea. Our findings revealed a significant decrease in ester-type catechins, crude protein, and protopectin, alongside a notable accumulation of non-ester-type catechins, gallic acid, and soluble components. The multi-enzyme system—comprising PPO/POD, pectinase/cellulase, and protease—cooperatively drove the oxidation of phenols, cell wall degradation, and the release of aromatic precursors. This was complemented by GC-MS analysis, which identified and quantified 103 volatile compounds across nine chemical classes. The total content of volatile compounds increased significantly, with alcohols, esters, and aldehydes/ketones being the dominant groups. Floral and fruity compounds such as linalool and geraniol accumulated continuously, while esters exhibited an initial increase followed by a decrease. Notably, carotenoid degradation products, including β-ionone, were significantly enriched during the later stages. This study revealed a “oxidation–hydrolysis–reconstruction” metabolic mechanism co-driven by microbial activity and a multi-enzyme system, providing a theoretical foundation for the precise regulation of pile fermentation and targeted quality improvement of primary dark tea.