Type 2 diabetes (T2D) presents a significant health challenge, underscoring the need for functional foods and nutraceutical hypoglycemic bioactive peptides for its prevention. This study investigates the potential of proteolytic hydrolysate from artificially cultivated Chinese giant salamander (CGS) meat, a rich protein source, as a preventive strategy for T2D. We produced a CGS meat hydrolysate (CGSh) and demonstrated its ability to inhibit the T2D drug target DPP-IV through in vitro assays. We identified five peptides (WRPPDH, WAPPSKD, IPDSPF, IPEMIF, and VPIAVPT) with high DPP-IV inhibitory activity in CGSh, suggesting its potential antidiabetic effects. In vivo experiments showed that CGSh effectively reduced insulin resistance in mice induced with a high-fat diet, as evidenced by a slower increase in blood glucose levels and a decreased HOMA-IR index. 16S rRNA sequencing analysis revealed that CGSh improved gut microbial homeostasis, promoting beneficial microorganisms and reducing harmful bacteria. Metabolomic analyses identified an increase in valeric acid levels and highlighted nine potential biomarker metabolites. By inhibiting metabolic pathways such as AGE-RAGE, CGSh may also prevent diabetic complications and reduce inflammation. These findings suggest that CGSh has a promising hypoglycemic effect, making it a potential functional food ingredient for T2D prevention and treatment.

Pu-erh tea, a traditional Chinese beverage, performs an anti-obesity function, but the correlation between its components and efficacy remains unknown. Here, we screened two Pu-erh teas with significant anti-obesity efficacies from 11 teas. In vitro experiments revealed that lipid accumulation in L02 cells and lipid synthesis in 3T3-L1 cells were significantly better inhibited by Tea-B than Tea-A. Further in vivo experiments using model mice revealed that the differences in chemical components generated two pathways in the anti-obesity efficacy and mechanism of Pu-erh teas. Tea-A changes the histomorphology of brown adipose tissue (BAT) and increases the abundance of Coriobacteriaceae_UCG_002 and cyclic AMP in guts through high chemical contents of cyclopentasiloxane, decamethyl, tridecane and 1,2,3-trimethoxybenzene, eventually increasing BAT activation and fat browning gene expression; the high content of hexadecane and 1,2-dimethoxy-benzene in Tea-B reduces white adipose tissue (WAT) accumulation and the process of fatty liver, increases the abundance of Odoribacter and sphinganine 1-phosphate, inhibits the expression of lipid synthesis and transport genes. These mechanistic findings on the association of the representative bioactive components in Pu-erh teas with the anti-obesity phenotypes, gut microbes, gut metabolite structure and anti-obesity pathways, which were obtained for the first time, provide foundations for developing functional Pu-erh tea.

Andrias davidianus (Chinese giant salamander, CGS) is the largest and oldest extant amphibian species in the world and is a source of prospective functional food in China. However, the progress of functional peptides mining was slow due to lack of reference genome and protein sequence data. In this study, we illustrated full-length transcriptome sequencing to interpret the proteome of CGS meat and obtain 10703 coding DNA sequences. By functional annotation and amino acid composition analysis, we have discovered various genes related to signal transduction, and 16 genes related to longevity. We have also found vast variety of functional peptides through protein coding sequence (CDS) analysis by comparing the data obtained with the functional peptide database. Val-Pro-Ile predicted by the CDS analysis was released from the CGS meat through enzymatic hydrolysis, suggesting that our approach is reliable. This study suggested that transcriptomic analysis can be used as a reference to guide polypeptide mining in CGS meat, thereby providing a powerful mining strategy for the bioresources with unknown genomic and proteomic sequences.

Ulcerative colitis (UC) is an incurable and highly complex digestive disease affecting millions of people worldwide. Compared to the current therapeutic drugs, bioactive peptides are more promising and safe substances as functional foods or drugs for the prevention and treatment of UC. The alcohol-soluble components from fermentation broth by fresh wheat germ and apple (AC-WGAF) were found to be effective in UC prevention in dextran sulfate sodium-induced mice in vivo. Herein, 4 novel peptides are identified from AC-WGAF by membrane ultrafiltration, recycling preparative high-performance liquid chromatography, and matrix-assisted laser desorption–ionization time-of-flight/time-of-flight mass spectrometry, possessing anti-colitis activity via using an in vitro model. One of those peptides named T24 (PVLGPVRGPFPLL) exhibited the most remarkable anti-colitis activity by preventing tight junction protein loss, maintaining epithelial barrier integrity, and promoting cell proliferation during in vitro and in vivo studies by regulating mitogen-activated protein kinase signaling pathways. Thus, T24 is a promising peptide as a functional food or novel drug for UC prevention and treatment.

Eucommia ulmoides Oliver is a native plant and valuable tonic Chinese medicine in China with a long history, great economic value and comprehensive development potential. Traditionally, the comprehensive utilization rate of E. ulmoides Oliv. is still very low, only bark has been used as medicine and other parts of Eucommia ulmoides Oliv. cannot be fully utilized, even the leaves have been well utilized in food products in Japan in the past decades. In order to improve the comprehensive utilization efficiency of E. ulmoides Oliv., in this review, we summarized the varieties and contents of main active compounds, biological functions and pharmacological effects in different parts of E. ulmoides Oliv. The findings suggest that other parts of E. ulmoides Oliv. could replace the bark of E. ulmoides Oliv. to some extent besides of their respective applications. The unique and extensive physiological functions between different parts of E. ulmoides Oliv. indicate that the comprehensive utilization of E. ulmoides Oliv. has a wide space to develop, which is also an effective way to protect E. ulmoides Oliv. resources and improve its the utilization rate.