Tannic acid alleviates 3-nitropropionic acid-induced ovarian damage in Brandt's vole (Lasiopodomys brandtii).

Tannic acid (TA) is a polyphenol with antioxidant properties present in various plants. In this study, we explored the protective effect of TA against ovarian oxidative stress in Brandt's voles and its underlying mechanism. At various doses, 3-nitropropionic acid (3-NPA) was intraperitoneally injected into Brandt's voles to simulate ovarian oxidative stress. Thereafter, various doses of TA were intragastrically administered to examine the protective effect of TA against 3-NPA-induced ovarian damage. Changes in inflammation, autophagy, apoptosis, and oxidative stress-related factors were investigated through various biochemical and histological techniques. Ovarian oxidative stress was successfully induced by the intraperitoneal administration of 12.5 mg/kg 3-NPA for 18 days. As a result, the ovarian coefficient decreased and ovarian tissue fibrosis was induced. TA treatment effectively alleviated the increase in luteinizing hormone and follicle-stimulating hormone levels; the decrease in estradiol, progesterone, and anti-Müllerian hormone levels; and the decline in fertility induced by 3-NPA. Compared to that in the 3-NPA group, TA decreased the expression of autophagy-related proteins beclin-1 and LC3, as well as the level of apoptosis. It also activated the AKT/mTOR signaling pathway, downregulated PTEN and p-NF-κB expression, and upregulated Nrf2 expression. In conclusion, our findings indicate that TA could inhibit autophagy via the regulation of AKT/mTOR signaling, suppressing oxidative damage and inflammatory responses through Nrf2 to alleviate 3-NPA-induced ovarian damage. Collectively, the current findings highlight the protective effects of TA in Brandt's vole, where it promotes the maintenance of normal ovarian function.

Construction of a polymer-based fluorescent probe with dual responsive sites for monitoring changes of lysosomal viscosity.

As highly dynamic organelles, lysosomes are involved in various physiological processes. The viscosity of lysosomes plays critical roles in maintaining their normal physiological function and abnormal variations of viscosity are associated with many diseases. Monitoring the changes of lysosomal viscosity could contribute to understanding lysosome-related physiological and pathological processes. In this work, based on an indole fluorophore and fluorescent polymer, poly(2-hydroxyethyl methacrylate) (PHEM), a new polymeric fluorescent probe, In-PHEM, with dual responsive sites for tracking changes of lysosomal viscosity is presented. In-PHEM showed excellent fluorescence properties and high photostability. With this robust probe, the variation of the lysosomal viscosity in cells under different physiological conditions, including inducer stimulation, the process of starvation and apoptosis, was monitored using dual-channel imaging. Therefore, this work may provide a powerful tool for monitoring changes of lysosomal viscosity and helping to understand the relationship between the viscosity changes of lysosomes and their related diseases.

Tannic Acid Induces Intestinal Dysfunction and Intestinal Microbial Dysregulation in Brandt's Voles (Lasiopodomys brandtii).

Brandt's vole (Lasiopodomys brandtii) is a small herbivorous mammal that feeds on plants rich in secondary metabolites (PSMs), including tannins. However, plant defense mechanisms against herbivory by Brandt's voles are not clearly established. This study aimed to investigate the effects of dietary tannic acid (TA) on the growth performance, intestinal morphology, digestive enzyme activities, cecal fermentation, intestinal barrier function, and gut microbiota in Brandt's voles. The results showed that TA significantly hindered body weight gain, reduced daily food intake, changed the intestinal morphology, reduced digestive enzyme activity, and increased the serum zonulin levels (p < 0.05). The number of intestinal goblet and mast cells and the levels of serum cytokines and immunoglobulins (IgA, IgG, TNF-α, IL-6, and duodenal SlgA) were all reduced by TA (p < 0.05). Moreover, TA altered ß-diversity in the colonic microbial community (p < 0.05). In conclusion, the results indicate that TA could damage the intestinal function of Brandt's voles by altering their intestinal morphology, decreasing digestive ability and intestinal barrier function, and altering microbiota composition. Our study investigated the effects of natural PSMs on the intestinal function of wildlife and improved our general understanding of plant-herbivore interactions and the ecological role of PSMs.