Yinchenhao Decoction mitigates intestinal impairment induced by high carbohydrate diet in largemouth bass: insights from inflammation, apoptosis, oxidative stress, tight junctions, and microbiota homeostasis

Abstract

Abstract As a major source of energy, carbohydrates have a protein sparing effect. However, excessive consumption of carbohydrates can harm the intestinal barriers of fish, particularly carnivorous fish. The traditional Chinese medicine component, Yinchenhao Decoction (YD), may improve intestinal barriers and microbial community equilibrium in both animals and humans. In the current investigation, a series of NC and HC with graded YD experiments were undertaken, and the results suggest that 2% and 4% YD treatments significantly reduced gut inflammation and mucosal loss caused by HC. Compared to NC, HC significantly decreased the relative expression of intestinal tight junction-related genes (ZO1, claudin1, claudin7, and occludin). However, with the application of YD, the expression of tight junction-related genes (ZO1, claudin1, and claudin7) increased significantly (p < 0.05). Stepwise, administration of YD significantly reduced elevated plasma diamine oxidase (DAO) activity caused by HC (p < 0.05). Additionally, YD significantly downregulated the mRNA expression of endoplasmic reticulum stress-related genes (GRP78, ATF6, CHOPα, IRE1, XBP1, and Eif2α) and pro-apoptosis genes (caspase3, caspase8, and bax) (p < 0.05), while upregulating the anti-apoptosis gene bcl2 (p < 0.05). Moreover, YD significantly increased the mRNA expression of antioxidant genes CAT and the enzyme activities of CAT and GPX, while decreasing keap1 and MDA concentration significantly (p < 0.05). Additionally, YD markedly decreased the expression of pro-inflammatory genes (IL1β, TNFα, IL8, and NF-κB) and the immune enzyme activity (ACP and AKP) (p < 0.05). By upregulating the expression of anti-inflammatory genes (IKB and IL10). I Notably, YD modulated the largemouth bass intestinal microbial community, enhancing the diversity and increasing the abundance of probiotic microorganisms in the intestinal microbiota. The study's results demonstrate that YD supplementation in a high-carbohydrate (HC) diet reduced inflammation, apoptosis, oxidative stress, and tight-junction injury in the intestines. Furthermore, it helped maintain gut microbiota homeostasis, suggesting that YD could be a valuable functional addition in aquaculture practices.