The effects of liquid-solid ratio, acetic acid concentration and extraction time on the yield of acid-soluble collagen(ASC) from the swim bladders of grass carp were optimized by statistical analysis using response surface methodology. The response surface methodology (RSM) was used to optimize the yield of ASC by implementing the Box-Wilson design. Statistical analysis of the results showed that the linear and quadric terms of these three variables had significant effects. However, no interactions between the three variables were found to contribute to the response at a significant level. The optimal conditions for higher yield of ASC were a liquid-solid ratio of 17.85, an acetic-acid concentration of 0.54 M and a time of 34 h. Under these conditions, the model predicted an ASC yield of 8.39%. Verification of the optimization showed that an ASC yield of 8.21±0.15% was observed under the optimal conditions. The experimental values agreed with the predicted values, using analysis of variance, indicating an excellent fit of the model used and the success of response surface methodology for modeling extraction of ASC from the swim bladders of grass carp.

Sangguayin (SGY), comprising four types of Chinese herbs, can be used as both food and medicine and has been clinically used to treat type 2 diabetes mellitus (T2DM) for a long time. Our previous study demonstrated the antidiabetic effect of SGY in experimental T2DM rats fed with a high‐fat diet and treated with a low dose of streptozotocin. However, its mechanism of action is questionable. In this study, we refined the traditional SGY decoction and investigated its antidiabetic activity in db/db mice. We evaluated the possible molecular mechanism using skeletal muscle tissues. The results show that the treatment with SGY preparation resulted in a decrease in the blood glucose, glycated serum protein, and blood lipid levels and an improvement in the glucose tolerance as well as insulin resistance. In addition, SGY preparation remarkably upregulated the expression of insulin receptor, insulin receptor substrate‐1, phosphoinositide 3 kinase (PI3K), protein kinase B (Akt), and glucose transporter type 4 (GLUT4). Thus, SGY preparation is an effective agent for the treatment of T2DM, and its molecular mechanism may be related to the regulation of PI3K/Akt signaling in the skeletal muscle.

Background: Although our team has demonstrated the antidepressant effect of Gardeniae Fructus oil (OGF) in the early stages, the mechanism of whether OGF works by regulating the gut microbiota is not clear. This study aims to elucidate OGF’s gut-brain axis mechanism in depression.Methods: Chronic unpredictable mild stress (CUMS) was used to establish a depressed mouse model, and the depression-like behavior of mice was observed by behavioral tests after antibiotic pretreatment and fecal microbiota transplantation (FMT). HE staining was used to observe the pathological changes in the hippocampus and colon; ELISA was used to detect the content of neurotransmitters and pro-inflammatory factors; Western blot was used to detect the expression of colonic tight junction proteins. The signaling pathways regulating the antidepressant properties of OGF were obtained by transcriptome sequencing analysis and validated at the protein level.Results: Compared with the CON group, mice in the CUMS group showed significant depressive-like behavior, pathological damage to the hippocampus and colon tissues, significant decrease in levels of 5-HT, DA, and BDNF in the hippocampus, significant increase in levels of IL-1β, IL-6, TNF-α, DAO, and LPS in serum, significant decrease in colonic tight junction protein expression, and significant increase in protein expression of TLR4, p-NF-κB, NLRP3, ASC, and IL-1β in the hippocampus (P < 0.01); Compared with the CUMS group, the FMT group could effectively improve the above situation (P < 0.05, P < 0.01), whose therapeutic effect was second only to the OGF group (P < 0.01), while ABX + OGF group did not show obvious therapeutic effect.Conclusion: OGF might exert antidepressant effects by modulating gut microbiota and mediating the hippocampal TLR4/NF-κB/NLRP3 pathway.

Depression poses a considerable threat to global health, underscoring the critical need for safe treatments. Because of its homology of medicine and food, Gardeniae Fructus is widely used in clinical and every-day life contexts. Gardeniae Fructus oil (OGF) is a waste byproduct of the food industry with promising recycling potential. While previous research has demonstrated the antidepressant effects of OGF, the precise mechanism remains unclear. To fill this gap in the literature, this paper elucidates the composition and potential antidepressant mechanism of OGF. According to the results, OGF is mainly composed of fatty acids and unsaponifiable matter. OGF could effectively attenuate depression-like behaviors in mice with chronic unpredictable mild stress by modulating the microbiota-gut-brain axis. Mechanisms include improving gut dysbiosis, regulating short-chain fatty acids, protecting the intestinal barrier function, reducing hippocampal damage, and alleviating neuroinflammation by inhibiting the activation of the TLR4/NF-κB/NLRP3 pathway. Fecal microbiota transplantation experiments confirmed the involvement of the gut microbiota in the modulation of depression-like behavior by OGF. This study establishes the antidepressant effects of OGF as well as the underlying mechanism, demonstrating its potential as a novel dietary intervention for depression treatment.

The renin-angiotensin system (RAS) is the primary pathway for regulating blood pressure in the body, and angiotensin-converting enzymes (ACEs) play a crucial role in it. Hirudo nipponia is an invertebrate that contains a variety of active peptides; however, there are no studies on the ACE inhibitory activity of hirudo. In the present study, our aim was to identify the active peptides in hirudo based on active peptide database analysis, unexpectedly filling the gap in hirudo ACE inhibitory activity research. Prep-HPLC was used to separate the part below 3 kD from hirudo. The peptide composition of the isolates was obtained based on Orbitrap LC-MS. The activity of each group of peptides was predicted by the database and the activity was determined by bioassay. Peptides with validation activity were screened through the database. In total, 337 peptides and 18 peptides matching the NCBI leech protein database were identified. All four fractions showed ACE inhibitory activity, and the IC50 was 0.8266, 0.2708, 0.4432, and 0.1764 mg/mL, respectively. Six screened peptides showed good affinity for ACE. This work reveals for the first time that low-molecular-weight peptides from H. nipponia have ACE inhibitory activity, which can provide a new explanation for leech treatment of hypertension.